Abstract: Provided is an image forming apparatus that realizes a distributed control system with a reduced number of power lines, and that has highly reliable power supply and an effective power saving mode. To accomplish this, the image forming apparatus employs a distributed control system including a master CPU, a plurality of sub master CPUs, and a plurality of slave CPUs. The master CPU supplies 5-V power to the sub master CPUs and the slave CPUs in the power saving mode, and supplies 24-V power thereto in a normal mode. Also, the sub master CPUs determine the operating mode in accordance with the level of the supplied power voltage, and operate accordingly.

Abstract: Image forming apparatus that forms an electrostatic latent image on a surface of a photosensitive member with a laser beam, including a generation unit configured to generate a high-speed clock and a low-speed clock mutually different in frequency, a scanning unit configured to perform scanning of the laser beam in a main scanning direction based on the low-speed clock, a detection unit configured to detect the laser beam during a scanning operation performed by the scanning unit, a first shift register unit configured to receive a detection signal from the detection unit according to the high-speed clock, and an output unit configured to receive a parallel output of the first shift register unit in synchronization with the low-speed clock and to output detection timing of the laser beam as a detection signal synchronized with the low-speed clock and a value corresponding to a shift number defined by the high-speed clock.

Abstract: There is provided an image forming apparatus which adopts a distributed control system and increases the error detection accuracy of each control unit. To accomplish this, the image forming apparatus includes a master control unit that controls the overall image forming apparatus, a plurality of sub-master control units that control a plurality of functions for performing image formation, and a plurality of slave control units that control loads for implementing a plurality of functions. The master control unit determines a diagnosis path for performing a diagnosis process for an error using the signal lines and a connection bridge connected to the respective control units. The master control unit performs the diagnosis process for an error in accordance with the determined diagnosis path.

Abstract: Image forming apparatus that forms an electrostatic latent image on a surface of a photosensitive member with a laser beam, including a generation unit configured to generate a high-speed clock and a low-speed clock mutually different in frequency, a scanning unit configured to perform scanning of the laser beam in a main scanning direction based on the low-speed clock, a detection unit configured to detect the laser beam during a scanning operation performed by the scanning unit, a first shift register unit configured to receive a detection signal from the detection unit according to the high-speed clock, and an output unit configured to receive a parallel output of the first shift register unit in synchronization with the low-speed clock and to output detection timing of the laser beam as a detection signal synchronized with the low-speed clock and a value corresponding to a shift number defined by the high-speed clock.

Abstract: A first lower layer control unit controls a conveyance unit, that conveys the medium in a first conveyance section of a conveyance path. A second lower layer control unit controls a conveyance unit, that conveys the medium in a second conveyance section located downstream of the first conveyance section. An upper layer control unit determines whether the medium is at a position where both the first lower layer control unit and the second lower layer control unit engage with conveyance control of the medium, instructs the first lower layer control unit and the second lower layer control unit to operate in synchronization with each other when the medium is at the position, and instructs the second lower layer control unit to operate asynchronously to the first lower layer control unit when the medium is not at the position.

Abstract: Image forming apparatus that forms an electrostatic latent image on a surface of a photosensitive member with a laser beam, including a generation unit configured to generate a high-speed clock and a low-speed clock mutually different in frequency, a scanning unit configured to perform scanning of the laser beam in a main scanning direction based on the low-speed clock, a detection unit configured to detect the laser beam during a scanning operation performed by the scanning unit, a first shift register unit configured to receive a detection signal from the detection unit according to the high-speed clock, and an output unit configured to receive a parallel output of the first shift register unit in synchronization with the low-speed clock and to output detection timing of the laser beam as a detection signal synchronized with the low-speed clock and a value corresponding to a shift number defined by the high-speed clock.

Abstract: An image forming apparatus capable of forming a high-resolution image without complicating a circuit construction. A difference between a phase of an operation clock for a ED detection unit and a phase of an operation clock for an image processing unit is measured by a phase measurement unit of the image forming apparatus, and a timing of data delivery between the BD detection unit and the image processing unit is adjusted by a BD input timing adjuster based on a measurement result. A difference between the phase of the operation clock for the image processing unit and a phase of an operation clock for a laser drive unit is measured by the phase measurement unit, and a timing of data delivery between the image processing unit and the laser drive unit is adjusted by an image output timing adjuster based on a measurement result.

Abstract: An image forming apparatus capable of forming a high-resolution image without complicating a circuit construction. A difference between a phase of an operation clock for a BD detection unit and a phase of an operation clock for an image processing unit is measured by a phase measurement unit of the image forming apparatus, and a timing of data delivery between the BD detection unit and the image processing unit is adjusted by a BD input timing adjuster based on a measurement result. A difference between the phase of the operation clock for the image processing unit and a phase of an operation clock for a laser drive unit is measured by the phase measurement unit, and a timing of data delivery between the image processing unit and the laser drive unit is adjusted by an image output timing adjuster based on a measurement result.

Abstract: The image forming apparatus has the plurality of control units and executes distributed processing in which any one control unit having monitoring execution authority monitors for an abnormal condition in each control unit. Each control unit determines, from its own processing load, monitoring capability information that indicates whether monitoring for an abnormal condition is possible or not. If, in a case where the control unit has the monitoring execution authority, the monitoring capability information does not satisfy predetermined information, then the control unit delegates the monitoring execution authority to another control unit whose monitoring capability information does satisfy the predetermined information.

Abstract: A first lower layer control unit controls a conveyance unit, that conveys the medium in a first conveyance section of a conveyance path. A second lower layer control unit controls a conveyance unit, that conveys the medium in a second conveyance section located downstream of the first conveyance section. An upper layer control unit determines whether the medium is at a position where both the first lower layer control unit and the second lower layer control unit engage with conveyance control of the medium, instructs the first lower layer control unit and the second lower layer control unit to operate in synchronization with each other when the medium is at the position, and instructs the second lower layer control unit to operate asynchronously to the first lower layer control unit when the medium is not at the position.

Abstract: The present image forming apparatus includes a first control unit and a second control unit driven by built-in clock oscillators to realize the distributed control. The first control unit generates, using a first timer driven by the built-in clock oscillator of the first control unit, a pulse signal corresponding to a predetermined clock rate and outputs the pulse signal to the second control unit. The second control unit measures, using a second timer driven by the built-in clock oscillator of the second control unit, a pulse width of the pulse signal outputted from the first control unit, and calculates a correction coefficient using reference pulse width corresponding to the predetermined clock rate and the measured pulse width. The processing unit processes using the calculated correction coefficient.

Abstract: A sheet processing apparatus configured to bind a sheet bundle includes a folding portion configured to fold the sheet bundle, a sheet processing portion provided upstream of the folding portion and configured to form a groove at a fold position of at least one sheet of the sheet bundle, and a controller configured to control an operation of the sheet processing portion. The controller controls an operation of the sheet processing portion such that a width of a groove formed on a sheet located on an outer side of the folded sheet bundle is larger than that of a groove formed on a sheet located on an inner side of the folded sheet bundle.

Abstract: Provided is an image forming apparatus that realizes a distributed control system with a reduced number of power lines, and that has highly reliable power supply and an effective power saving mode. To accomplish this, the image forming apparatus employs a distributed control system including a master CPU, a plurality of sub master CPUs, and a plurality of slave CPUs. The master CPU supplies 5-V power to the sub master CPUs and the slave CPUs in the power saving mode, and supplies 24-V power thereto in a normal mode. Also, the sub master CPUs determine the operating mode in accordance with the level of the supplied power voltage, and operate accordingly.

Abstract: This invention provides an image forming apparatus that suppresses a control error between CPUs when the CPUs operate in cooperation with each other in distributed control by the CPUs. To accomplish this, the image forming apparatus utilizes a distributed control system. Respective CPUs measure time interval concerning image formation processing using their built-in clock oscillators, and perform operations in cooperation with each other. Correction coefficients are calculated based on the time interval measured by the respective CPUs to correct a measurement error generated by the operation an error of the respective clock oscillators. Clock count values each indicating a timing to drive a load is corrected based on the correction coefficients.

Abstract: An image forming apparatus capable of forming a high-resolution image without complicating a circuit construction. A difference between a phase of an operation clock for a BD detection unit and a phase of an operation clock for an image processing unit is measured by a phase measurement unit of the image forming apparatus, and a timing of data delivery between the BD detection unit and the image processing unit is adjusted by a BD input timing adjuster based on a measurement result. A difference between the phase of the operation clock for the image processing unit and a phase of an operation clock for a laser drive unit is measured by the phase measurement unit, and a timing of data delivery between the image processing unit and the laser drive unit is adjusted by an image output timing adjuster based on a measurement result.

Abstract: There is provided an image forming apparatus which adopts a distributed control system and suppresses generation of radiation noise without increasing the cost. To accomplish this, the image forming apparatus includes a master control unit that controls the overall image forming apparatus, a plurality of sub-master control units that control a plurality of functions for performing image formation, and a plurality of salve control units that control loads for implementing a plurality of functions. The image forming apparatus performs distributed control. The image forming apparatus determines the operating frequencies of the salve control units in accordance with loads controlled by the salve control units. The image forming apparatus compares the operating frequencies of the slave control units. Based on the comparison result, the image forming apparatus changes the operating frequency of a slave control unit that is equal to the operating frequency of another slave control unit.

Abstract: There is provided an image forming apparatus which adopts a distributed control system and increases the error detection accuracy of each control unit. To accomplish this, the image forming apparatus includes a master control unit that controls the overall image forming apparatus, a plurality of sub-master control units that control a plurality of functions for performing image formation, and a plurality of salve control units that control loads for implementing a plurality of functions. The master control unit determines a diagnosis path for performing a diagnosis process for an error using the signal lines and connection bridge connected to the respective control units. The master control unit performs the diagnosis process for an error in accordance with the determined diagnosis path.

Abstract: There are provided an image forming apparatus which implements divisional control using a plurality of control units without an increase in cost and a control method for the apparatus. To accomplish this, this image forming apparatus includes a master control unit that controls the overall image forming apparatus, a plurality of sub-master control units that control a plurality of functions for performing image formation, and a plurality of salve control units that control loads for implementing a plurality of functions. The master control unit is connected to the plurality of sub-master control units via first signal lines. The plurality of sub-master control units are connected to the plurality of slave control units via second signal lines higher in data transfer timing accuracy than the first signal lines.

Abstract: This invention provides an image forming apparatus to which a distributed control system is applied and which improves error detection accuracy in each control unit. To accomplish this, the image forming apparatus includes a master control unit which controls the overall image forming apparatus, a plurality of sub-master control units which control a plurality of functions required to implement image formation, and a plurality of slave control units which control loads required to implement the plurality of functions. Each slave control unit includes a monitoring unit which monitors the operation of the other active slave control unit and performs an error diagnosis when the slave control unit is inactive.

Abstract: A sheet processing apparatus configured to bind a sheet bundle includes a folding portion configured to fold the sheet bundle, a sheet processing portion provided upstream of the folding portion and configured to form a groove at a fold position of at least one sheet of the sheet bundle, and a controller configured to control an operation of the sheet processing portion. The controller controls an operation of the sheet processing portion such that a width of a groove formed on a sheet located on an outer side of the folded sheet bundle is larger than that of a groove formed on a sheet located on an inner side of the folded sheet bundle.