Abstract: An image forming apparatus in which the intensity of a light beam used to form a latent image is switched in response to a change in resolution. A laser emits a light beam for forming a latent image on a photosensitive drum. A polygon mirror scans the emitted light beam. BD sensors detect the scanned beam. A timing controller selects the preferable timing from a storage device table according to the intensity of the light beam or the resolution when controlling the light emission timing of the lasers in response to a detection of timing of the detected light beam.

Abstract: A full-color image forming apparatus has a cooling fan switchable between rotating speeds of “full speed” and “half speed.” A transfer portion thermistor is installed near a photosensitive drum and an intermediate transfer member, and a printer control portion controls the rotating-speed switching of a cooling fan based on the temperature detected by the transfer portion thermistor. The printer control portion sets the rotating speed of the cooling fan at “half speed” when print job is started, sets a fan speed switching threshold value at 30° C. during the print job of only the single-side printing, sets the fan speed switching threshold value at 25° C. during a duplex print job, and switches the cooling fan to “full speed” when the detection temperature is higher than the set fan speed switching threshold value.

Abstract: An image forming apparatus that is capable of carrying out image formation on a recording medium such as plain paper without increasing the FCOT (First Copy Out Time) and is also capable of carrying out optimal image formation on a recording medium, such as thick paper, for which the processing speed is reduced with no registration misalignment between the leading ends of toner images and the leading end of the recording medium. An image is primarily transferred onto a rotatively driven image carrier, and the image on the image carrier is secondarily transferred onto a recording medium. An image writing reference position signal for starting image formation is issued based on the circumference of the image carrier which is the length of the image carrier in the direction of rotation thereof or based on a detected reference position on the image carrier.

Abstract: An image formation device changes the rotational rate of a polygon motor, i.e. the main-scanning rate, and selects one of pulse width conversion tables when an image formation is performed multiple times on a single sheet of transfer paper. The changing of the main-scanning rate is for preventing inconsistent sizes between a first recorded image and a second recorded image caused by shrinkage of transfer paper. The pulse width conversion tables allow the pulse widths to be modulated.

Abstract: An image forming apparatus that is capable of carrying out image formation on a recording medium such as plain paper without increasing the FCOT (First Copy Out Time) and is also capable of carrying out optimal image formation on a recording medium, such as thick paper, for which the processing speed is reduced with no registration misalignment between the leading ends of toner images and the leading end of the recording medium. An image is primarily transferred onto a rotatively driven image carrier, and the image on the image carrier is secondarily transferred onto a recording medium. An image writing reference position signal for starting image formation is issued based on the circumference of the image carrier which is the length of the image carrier in the direction of rotation thereof or based on a detected reference position on the image carrier.

Abstract: An image forming apparatus which enables the user to easily remove a sheet bundle left in the apparatus after a bookbinding-mode job is stopped in the middle of execution thereof. In a bookbinding mode of the apparatus, in a sheet stacking section, a plurality of sheets having images formed thereon are stacked as a sheet bundle; in a gluing section, glue is applied to an end face of the sheet bundle; and in a bonding section, a cover sheet is bonded to the sheet bundle to wrap the sheet bundle in the cover sheet. When a bookbinding-mode job is canceled during execution thereof, in the gluing section, glue is applied to the sheet bundle stacked in the stacking section before the job is stopped, and a discharge section discharges the glue-applied sheet bundle which is neither wrapped nor trimmed.

Abstract: An image forming apparatus which is capable of eliminating density irregularities of an image formed caused by potential irregularities of the photosensitive member when the drum is irradiated by a beam of constant luminous intensity. A laser driver irradiates a beam modulated based on an image signal onto a photosensitive member. A current controller variably controls a driving current for driving the laser driver. A PWM pulse width converter modulates a pulse width of the beam based on the image signal. A potential sensor measures the potential of the photosensitive member after the photosensitive member is irradiated by a beam having a predetermined luminous intensity. A selector causes the current controller to correct the driving current based on low frequency components of irregularities of the potential and changes a modulation coefficient used for modulating the pulse width based on high frequency components of the irregularities of the potential.

Abstract: This invention can improve the appearance quality of a pamphlet produced by suppressing a swell of a folded sheet bundle and prevent a drop in productivity without enlarging the size of a sheet processing apparatus. A sheet bundle receiving position is changed depending on a sheet size and the moving direction of the press unit is changed corresponding to the sheet size of a conveyed sheet bundle. As a consequence, the enlargement of the sheet processing apparatus can be avoided without deteriorating productivity.

Abstract: A sheet post-processing apparatus has a sheet conveying portion which receives and conveys a sheet discharged from an apparatus on an upstream side, and discharges it to an apparatus on a downstream side or a discharge tray, a sheet post-processing portion which carried out post-processing on the sheet, and a power saving control portion which renders the sheet post-processing apparatus into a power saving state, and the power saving control portion maintains electric power supply to the sheet conveying portion, and interrupts electric power supply to the sheet post-processing portion. The sheet post-processing apparatus, even in the power saving state, is capable of discharging the sheet discharged from the apparatus on the upstream side to the apparatus on the downstream side or a discharge tray.

Abstract: A binding apparatus which can meet user requests and adapt to usage conditions by a user. An adhesive is heated and melted, and then applied to a sheet bundle to bind the sheet bundle. One of the following modes is selected: a first adhesive temperature adjusting mode in which the adhesive is heated when power supply to the bookbinding apparatus is turned on, and a second adhesive temperature adjusting mode in which the adhesive is heated when binding of the sheet bundle is started.

Abstract: An image forming apparatus including: a stapling device which applies staple processing to a portion assuming a trailing end of a sheet with respect to a transport direction of the sheet; a first punch device which applies punch processing to a portion assuming a leading end of the sheet in the transport direction of the sheet; and a second punch device which applies the punch processing to the portion assuming the trailing end of the sheet in the transport direction of the sheet, in which a setting of both a staple mode for performing the staple processing by the stapling device and a first punch mode for performing the punch processing by the first punch device is inhibited, and a setting of both the staple mode and a second punch mode for performing the punch processing by the second punch device is allowed.

Abstract: An image formation device changes the rotational rate of a polygon motor, i.e. the main-scanning rate, and selects one of pulse width conversion tables when an image formation is performed multiple times on a single sheet of transfer paper. The changing of the main-scanning rate is for preventing inconsistent sizes between a first recorded image and a second recorded image caused by shrinkage of transfer paper. The pulse width conversion tables allow the pulse widths to be modulated.

Abstract: A water content determination apparatus which are capable of precisely determining water content contained in a medium regardless of an environment where an image forming apparatus is installed. The water content determination apparatus. A signal in accordance with presence or absence of a medium in an electrostatic capacitance region formed on a paper path is outputted where the medium for image forming is conveyed. Temperature in the water content determination apparatus is determined based on an output signal of the detection device in absence of the medium passing in the electrostatic capacitance region. Water content contained in the medium is determined based on the output signal of the detection device in absence of the medium passing in the electrostatic capacitance region, the output signal of the detection device in presence of the medium passing in the electrostatic capacitance region, and the temperature determined by the temperature determination device.

Abstract: When a plurality of toner containers mounted on a developing rotary unit are simultaneously determined as toner-absent toner containers, toner container replacement may not be efficient because toner containers are replaced at a replacement position. Therefore, when the toner containers mounted on the developing rotary unit are simultaneously determined as toner-absent toner containers, a toner container to be preferentially replaced is selected so as to be able to be placed at a replacement position by considering the usability of the toner containers.

Abstract: An image-forming apparatus includes a rotatable photoreceptor carrying a toner image thereon, a rotatable intermediate transfer member, a primary transfer device facilitating primary transfer of the toner image from the photoreceptor onto the intermediate transfer member, a secondary transfer device facilitating secondary transfer of the toner image from the intermediate transfer member onto a sheet, and a controller controlling rotation speed of the intermediate transfer member. The controller sets the rotation speed at a first speed during primary transfer. After primary transfer and a delay period, the controller changes the rotation speed to a second speed. The controller determines which rotation of the intermediate transfer member to change the speed.

Abstract: An image forming apparatus includes a photosensitive member, an intermediate transfer material, a first transfer device, a second transfer device, a feed device, a refeed device, and a controller which executes selectively first and second modes, in which one or two images are formed on one round of the intermediate transfer material. An image, which should be formed on a refed sheet, is formed on a first half area on one round of the intermediate transfer material, and an image, which should be formed on a fed sheet, is formed on a second half area on one round, in a case of executing the second mode when performing image formation on both sides of a sheet. The first mode is executed before returning to the second mode after executing the first mode instead of executing the second mode when performing both side image formation.

Abstract: A full-color image forming apparatus has a cooling fan switchable between rotating speeds of “full speed” and “half speed.” A transfer portion thermistor is installed near a photosensitive drum and an intermediate transfer member, and a printer control portion controls the rotating-speed switching of a cooling fan based on the temperature detected by the transfer portion thermistor. The printer control portion sets the rotating speed of the cooling fan at “half speed” when print job is started, sets a fan speed switching threshold value at 25° C. during the print job of only the single-side printing, sets the fan speed switching threshold value at 30° C. during a duplex print job, and switches the cooling fan to “full speed” when the detection temperature is higher than the set fan speed switching threshold value.

Abstract: An image forming apparatus generates a PWM signal corresponding to input image data and controls a timing of a light source to emit a light beam based on the PWM signal in order to perform tone reproduction. The image forming apparatus includes a data processing unit configured to generate the PWM signal for one pixel based on image data for continuous two pixels in the image data. The data processing unit selects an origin of pulse growth in generation of the PWM signal for one pixel in accordance with the image data for the two pixels to generate the PWM signal.

Abstract: In order to reduce a driving time for a scanner motor that rotates the polygon mirror, when it is within a predetermined time period after the power has turned ON or opening/closing of the door has been detected, the driving of the scanner motor is prohibited, even though a print-preparation request created through key operation, opening/closing of the document feeder, setting documents into the document feeder, or the like, is issued; when it is not within a predetermined time period after the power has turned ON or opening/closing of the door has been detected, in order to shorten the first-print time, the scanner motor is driven in response to a print-preparation request.

Abstract: An image forming apparatus in which the intensity of a light beam used to form a latent image is switched in response to a change in resolution. A laser emits a light beam for forming a latent image on a photosensitive drum. A polygon mirror scans the emitted light beam. BD sensors detect the scanned beam. A timing controller selects the preferable timing from a storage device table according to the intensity of the light beam or the resolution when controlling the light emission timing of the lasers in response to a detection of timing of the detected light beam.