Abstract: A drive transmission device that performs drive transmission through a plurality of systems and includes a first involute spline joint to perform drive transmission to a primary rotating body to be driven and a second involute spline joint to perform drive transmission to a secondary rotating body to be driven.

Abstract: An image forming system, in which a method of detecting a misregistration of a color image is performed, includes multiple image carriers, an optical writing unit, a transfer member extended by a drive roller and at least one driven roller, a rotation detector, a roller driving unit, a belt controller, an image detector configured to detect the images formed on the surface of the transfer member and obtain detection data, and a controller configured to calculate an amount of misregistration and correct relative misregistration of a scanning line between the image carriers based on a result of the calculation. In the image forming system, a distance from a transfer position to a detection position is an integer multiple of a travel distance of the transfer member during one revolution of the at least one driven roller.

Abstract: An image forming apparatus that includes a plurality of image bearing members, a plurality of drive sources each including a drive gear, a plurality of driven gears, a visible image forming unit, an endless traveling member, a transfer unit, an image detection unit, and a controller. The controller controls rotation of the plurality of image bearing members according to a velocity fluctuation pattern of each surface of the image bearing members based on a detection time interval between predetermined visible detection images formed on the surface of the image bearing member and transferred therefrom to the endless traveling member detected by the image detection unit. Each of the plurality of driven gears includes a gear portion and an engaging portion integrated therewith. The gear portion includes a geared circumference and the engaging portion engages the image bearing member.

Abstract: After detecting a speed fluctuation pattern per rotation of a photosensitive drum, a process that forms an image based on image data while causing the photosensitive drum to rotate at a nonstandard linear speed is executed as an image forming process by driving a process driving motor that drives the photosensitive drum to curb a speed fluctuation of the photosensitive drum by using a driving speed fine tuning pattern. Before executing the image forming process, a fine-tuning-pattern correcting process is executed for correcting the driving speed fine tuning pattern of the process driving motor, based on the nonstandard linear speed.

Abstract: An image forming apparatus includes at least first, second and third image carriers, a first drive source, a second drive source, at least one visible image forming mechanism for forming a visible image on the image carriers, a transfer unit for overlappingly transferring the visible images, an image detector, and a controller. The first drive source transmits a driving force to at least the first image carrier. The second drive source transmits a driving force to at least two image carriers other than the first image carrier. The controller calculates an amount of misalignment of the overlapped visible images that remain at the start timing of image formation based on the start timing of image formation after the timing correction, and separately determines driving speeds of the first and the second drive sources based on the amount of misalignment of the overlapped visible images.

Abstract: In cases where the transfer positions of toner images of respective colors that are formed on respective photosensitive bodies show a positional deviation, the rpm values of driving parts that drive the photosensitive bodies are adjusted in accordance with the amount of the positional deviation so that the linear velocities of the photosensitive bodies are constant. Alternatively, in the speed setting processing in which specified reference toner images are formed on the respective photosensitive bodies at a specified timing and are transferred onto an intermediate transfer belt, and then the relative amounts of mutual positional deviation of the respective reference toner images are calculated on the basis of the timing at which the respective reference toner images are detected by toner image detection sensors, and the driving speeds of the respective photosensitive bodies are individually set on the basis of the results of these calculations.

Abstract: In accordance with the present invention, a transparent or semitransparent window is formed in a developing device or a process cartridge to allow one to see the inside of the developing device via the window from the outside. The window may preferably be formed in the top wall of the developing unit or that of the process cartridge.

Abstract: An image forming apparatus, in which a program for carrying out an image forming method is provided, includes a transfer member to receive respective images formed on a plurality of image bearing members, an image detecting unit to detect the images conveyed on the transfer member, a paper length detecting unit to detect a length of a recording medium in a sheet travel direction, a counting unit to count the number of recording media and to change a count up value according to a detection result by the paper length detecting unit, and a control unit to control an image forming timing with respect to the image bearing members based on a detection timing of the image and to perform a positional deviation adjustment each time a counted value increases by a predetermined amount so as to reduce an amount of a positional deviation of the image.

Abstract: An image forming apparatus is disclosed. In at least one embodiment, the apparatus includes a plurality of image carriers to carry an image; a plurality of drivers to drive the image carriers; a plurality of drive-force transmitting members to transmit a driving-force from the drivers to image carriers; a developing unit, provided to the image carriers, to develop the image; a transfer member, facing the image carriers, to receive the image from the image carriers sequentially; an image detector to detect the image on the transfer member to check a detection timing of the image; a sensor, provided to each of the image carriers, to detect a rotational speed of image carriers; and a controller to conduct an image-to-image displacement control, a speed-deviation checking, and a phase adjustment control for each of the plurality of image carriers with the image detector and sensor.

Abstract: An image forming apparatus includes a plurality of image carriers, an optical writing unit, a plurality of developing units, a transfer member, a transfer unit, an image sensor, and a control unit. In at least one embodiment, the image sensor is configured to sense a positional displacement detection pattern including visible images on the transfer member to detect a positional displacement between the visible images on each of the plurality of image carriers. The control unit is configured to execute a positional displacement correction control to calculate an amount of the positional displacement and determine respective target drive speeds of the plurality of drive sources. The control unit is also configured to control so that the positional displacement detection pattern is formed when the plurality of drive sources are driven at substantially identical speeds and the positional displacement detection pattern thus formed is sensed by the image sensor.

Abstract: An imaging apparatus is disclosed that includes plural image carriers on which different-colored toner images are formed, the image carriers being driven and rotated to transfer the different-colored toner images onto one of an endless transfer member that is driven to rotate in contact with the image carriers or a transfer material that is carried by the endless transfer member. The imaging apparatus includes a phase calculating unit that extracts a periodic rotational variation component of each of the image carriers from a combination of periodic rotational variation components generated within said imaging apparatus and calculates a rotational phase of each of the image carriers based on the extracted periodic rotational variation component, and a rotational phase adjusting unit that adjusts a rotation stop phase of each of the image carriers based on the calculated rotational phase.

Abstract: An image forming apparatus to form an image on a recording medium, capable of reducing deterioration of image bearer, is disclosed. In one embodiment, the image forming apparatus includes an image bearer, a driver to move the image bearer, a image forming device to form a visible image on the image bearer, a contacting member to form a nip by contacting with the image bearer, and a controller to control the driver for driving stop with a distance shifted on a surface of the image bearer from a start of driving. An amount of the shifted distance is greater than a width of the nip and is not a divisional number of a peripheral length of the image bearer.

Abstract: An image forming apparatus includes a plurality of image bearing members, each of which is configured to bear a portion of a pattern image including a plurality of reference images in a given form, an endless moving member facing the plurality of image bearing members and configured to receive the pattern image, an image detecting unit configured to detect the plurality of reference images, a rotational angle detecting unit configured to separately detect each image bearing member at a given rotational angle, and a controller configured to detect a speed deviation pattern for each revolution of each image bearing member. The controller is configured to detect the speed deviation pattern based on a result obtained from a phase component and a quadrature component of a frequency signal generated from the detection result obtained by the rotational angle detecting unit and a result of detecting the plurality of reference images in the pattern image transferred onto the endless moving member.

Abstract: An image forming apparatus includes a latent image carrier having a moving surface on which a latent image is formed, a drive control mechanism to control a drive of the latent image carrier so as to match a rotation angular speed of the latent image carrier with a target rotation angular speed thereof, a surface moving member having a moving surface on which an adjustment pattern for use in controlling the drive of the latent image carrier is formed, an image forming mechanism to develop the latent image with toner and transfer a resultant toner image on the surface moving member so as to form the adjustment pattern along a surface moving direction thereof, a pattern sensor to detect the adjustment pattern, a correction mechanism to correct the target rotation angular speed of the latent image carrier based on an amplitude and a phase of a variable component in a pattern interval of the adjustment pattern detected with the pattern sensor.

Abstract: An image forming apparatus is disclosed. In at least one embodiment, the apparatus includes a plurality of image carriers to carry an image; a plurality of drivers to drive the image carriers; a plurality of drive-force transmitting members to transmit a driving-force from the drivers to image carriers; a developing unit, provided to the image carriers, to develop the image; a transfer member, facing the image carriers, to receive the image from the image carriers sequentially; an image detector to detect the image on the transfer member to check a detection timing of the image; a sensor, provided to each of the image carriers, to detect a rotational speed of image carriers; and a controller to conduct an image-to-image displacement control, a speed-deviation checking, and a phase adjustment control for each of the plurality of image carriers with the image detector and sensor.

Abstract: An image forming method in which an electrostatic latent image is formed by exposure with an exposure light of light scanning means onto an image carrier charged by charging means, visualization of the electrostatic latent image as a toner image, transfer of the toner image onto a transfer member by application of a bias voltage, and removal of the toner remaining on the image carrier following transfer with a cleaning blade, the exposure being initiated by the light scanning means after a position“a” on the image carrier where said bias voltage has been initiated passes the cleaning blade.

Abstract: A color printing apparatus having a color registration difference correction function, the color registration difference caused by a difference of rotation speeds of each photosensitive drum after a print mode changes from a one photosensitive drum mode to an all photosensitive drums mode.

Abstract: A color-drift correcting method in an image forming apparatus includes a first and a second color-drift correcting. The first color-drift correcting includes correcting the color-drift amount in a sub scanning direction and a skew relative to the reference color image being based on each color-drift amount of at least three mark-patterns, each of which mark-pattern is formed each color image, so as to decide a corrected-image line as a virtual image line for each color, assumed when the color images are superposed onto a transfer media. A second color-drift correcting includes correcting the color-drift amount in the sub scanning direction so that the virtual image lines corresponding to each of the colors other than the reference color intersect with the virtual image line of the reference color at at least two points.

Abstract: A transmission comprises a rotary shaft; a gear secured to the rotary shaft coaxially; and a regulative member secured to the rotary shaft. This regulative member press-contacts one end of the gear to maintain the gear exactly perpendicular to an axis of the rotary shaft. A photosensitive drum is fit to the gear. The regulative member is secured on the rotary shaft by press fitting.

Abstract: An image forming apparatus includes image forming units, a toner supply device, a common-unit detection device, an initial operation execution device, and a determination device. Each image forming unit is detachably provided in the image forming apparatus, and includes at least a development device containing toner. At least two of the image forming units are common image forming units having a common structure. When the common-unit detection device detects a common image forming unit at installation thereof, the initial operation execution device supplies a predetermined amount of toner to a development device of the common image forming unit and mixes to charge the toner by friction for a predetermined time period. Then, the. determination device detects whether the toner in the development device is charged to a predetermined level, and determines, based on the detection, whether to mix the toner one more time for another predetermined time.