Patent application number | Description | Published |
20080253785 | IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD - An image forming apparatus capable of reducing damage in a fixing section and printing a high-quality image on a sheet at low cost without reducing productivity. A sheet shifting mechanism is arranged upstream of a transfer roller and moves the sheet in a sheet lateral direction orthogonal to the sheet conveying direction. In order to change a position at which a sheet passes through a fixing roller, the sheet shifting mechanism is controlled for every conveyance of a predetermined number of sheets, whereby sheet movement in the sheet lateral direction is controlled. A correction amount for an error due to sheet shifting by the sheet shifting mechanism is stored for each of sheet shift positions. An image forming position in the sheet lateral direction of a photosensitive drum is shifted on the basis of the sheet shift position and the stored correction amount. | 10-16-2008 |
20080253818 | IMAGE FORMING APPARATUS AND CONTROL METHOD THEREFOR - An image forming apparatus that can satisfy productivity at the time of double-sided image formation without jamming due to a collision of a succeeding sheet with a preceding sheet, and without upsizing of the apparatus. The image forming apparatus performs a sheet circulation transport for circulating and transporting a sheet to an image forming unit to perform image formation on both a first side and a second side of the sheet. The sheet is fed to the image forming unit at a predetermined image formation start timing for the first side image formation. The first side image-formed sheet is reversed, and re-fed to the image forming unit for the second side image formation while causing the first side image-formed sheet to wait at least one of sheet waiting positions. A full state where all the sheet waiting positions are full of the first side image-formed sheets is detected. The sheet feeding unit is controlled so that the number of sheets on which the sheet circulation transport is performed is greater than the number of the sheet waiting positions. When the full state detecting unit detects the full state, the sheet re-feeding unit is controlled so that a head sheet among the first side image-formed sheets waiting at the sheet waiting positions is fed in advance of the predetermined image formation start timing. | 10-16-2008 |
20100117289 | IMAGE FORMING SYSTEM - An image forming system having: a sheet feeding unit which cuts a roll sheet and feeds cut sheets; a stack unit which stacks and stores the sheets fed by the sheet feeding unit and feeds the stored sheets; an image forming portion which forms an image on the sheets fed from the stack unit; and a controlling unit configured to control the feeding unit and the stack unit so that the stack unit feeds a sheet stored in the stack unit to the image forming portion when the sheet feeding unit feeds a sheet to the stack unit so as to stack the sheet from the sheet feeding unit into the stack unit. | 05-13-2010 |
20110280643 | IMAGE FORMING APPARATUS IMPROVED IN OPERABILITY FOR PRINT JOB INVOLVING SINGLE-SIDED PRINTING AND DOUBLE-SIDED PRINTING - An image forming apparatus capable of improving productivity in a print job mixedly involving single-sided printing and double-sided printing. Sheets are fed one by one to an image forming section. When double-sided printing is to be performed, a sheet having an image formed on the first side thereof by the image forming section is re-fed thereto so as to have an image formed on the second side thereof. When a sheet for double-sided printing exists, which is posterior in page order to a sheet for single-sided printing, an image forming order is changed such that the first side of the sheet for double-sided printing is subjected to image formation prior to the sheet for single-sided printing. When it is predicted that a state will occur in which the sheet for single-sided printing cannot be fed, the image forming order is not changed. | 11-17-2011 |
20110286756 | IMAGE FORMING APPARATUS - An image forming apparatus, which forms an image on a recording medium, including: an image bearing member; a toner image forming portion configured to form a toner image on the image bearing member; a transfer device configured to transfer the toner image formed on the image bearing member to the recording medium; a fixing device configured to pressurize and heat the recording medium to which the toner image is transferred, to fix the toner image on the recording medium; and a control circuit portion configured to control a temperature of the fixing device, wherein the control circuit portion controls a temperature of the fixing device for a first recording medium considering a temperature of the fixing device for a second recording medium to be fixed after the first recording medium. | 11-24-2011 |
20130202338 | IMAGE FORMING APPARATUS IMPROVED IN OPERABILITY FOR PRINT JOB INVOLVING SINGLE-SIDED PRINTING AND DOUBLE-SIDED PRINTING - An image forming apparatus capable of improving productivity in a print job mixedly involving single-sided printing and double-sided printing. Sheets are fed one by one to an image forming section. When double-sided printing is to be performed, a sheet having an image formed on the first side thereof by the image forming section is re-fed thereto so as to have an image formed on the second side thereof. When a sheet for double-sided printing exists, which is posterior in page order to a sheet for single-sided printing, an image forming order is changed such that the first side of the sheet for double-sided printing is subjected to image formation prior to the sheet for single-sided printing. When it is predicted that a state will occur in which the sheet for single-sided printing cannot be fed, the image forming order is not changed. | 08-08-2013 |
20150210494 | IMAGE FORMING APPARATUS - An image forming apparatus includes a stacking portion on which a sheet is to be stacked, an image forming unit, a size detection unit, a setting unit, a notification unit, and a control unit. The image forming unit forms an image on a sheet fed from the stacking portion. The size detection unit detects a size of a sheet stacked on the stacking portion. The setting unit sets at least one sheet size to be allowed for use at the image forming apparatus. The notification unit provides notification of information. The control unit causes the notification unit to provide a warning in a case where the size of the sheet detected by the size detection unit is not included in the at least one sheet size set by the setting unit. | 07-30-2015 |
20150241808 | IMAGE FORMING APPARATUS THAT FORMS COLOR IMAGE BY SUPERIMPOSING PLURALITY OF IMAGES IN DIFFERENT COLORS - An image forming apparatus includes: a generation unit configured to generate correlation data indicating a relationship between a relative position of a first image and a second image corresponding to a first speed and a relative position of the first image and the second image corresponding to a second image forming speed; a controller configured to, in a case where a image forming unit forms an image at the second speed, correct a relative position of the first image and the second image based on first information and on correlation data; and a prohibition unit configured to prohibit formation of the measurement image at the second speed in a case where a housing unit does not house a predetermined recording material corresponding to the second speed. | 08-27-2015 |
20150242714 | IMAGE FORMING APPARATUS THAT FORMS COLOR IMAGE BY SUPERIMPOSING PLURALITY OF IMAGES - An image forming apparatus includes a unit configured to correct a relative position of a first image and a second image, and a controller configured to form a first measurement image in a case where a first condition is satisfied, and to form the first measurement image and a second measurement image in a case where a second condition is satisfied. The controller is further configured to, in a case where the first condition is satisfied, determine whether or not the second condition is satisfied before the first condition is satisfied next, and in a case where the second condition is satisfied before the first condition is satisfied next, cause an image forming unit to form the first measurement image and the second measurement image. | 08-27-2015 |