Canon Kabushiki Kaisha

Shigeo Hata

Akihiko Sakai

Katsuhide Koga

Satoru Yamamoto

Keita Takahashi

Hirotaka Seki

Shoji Takeda

Atsushi Otani

Kiyoshi Okamoto

Yoshihito Osari

Shingo Kitamura

Michio Kawase

Yasuyuki Aiko

Takashi Nagaya

Noriyoshi Chizawa

Takashi Birumachi

Masashi Oyumi

Hiroshi Tanioka

Daisaku Kamiya

Naohisa Nagata

Takeo Yamamoto

Mitsuhiro Ota

Mitsuru Amimoto

Toshihiko Ohtsubo

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.

Image forming apparatus

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.

Image forming apparatus implemented by a distributed control system

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.

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.

A plurality of subsystems having diverse individual functions can be connected to an image forming apparatus. Each of the subsystems is made up of, for example, plural kinds of units which are different in performance from each other. Each of the units has inherent information related to the performance, and decides the operation specification of the entire image forming apparatus according to the combination of those units.

One scanning interval of a laser beam is divided into a plurality of blocks, correction data, which corresponds to optical characteristics of an optical unit placed between a laser element and a photosensitive drum, is stored in memory in association with each block, the correction data corresponding to a block being scanned by the laser beam is read out of the memory, and the laser is driven upon correcting the laser drive signal based upon the correction data read out and correction data corresponding to a block adjacent to the block being scanned by the laser.

Image forming apparatus and method of controlling same

A toner density detection apparatus has a sensor unit and a controller. The sensor unit irradiates a toner patch formed on an image carrier with light, splits the light reflected by the toner patch into first and second light components, receives the first and second light components, and outputs first and second light reception signals. The controller causes an analog/digital converter to convert, based on a reference voltage, the output first and second light reception signals into first and second digital data, and detects the density of the toner patch based on the first and second digital data. The toner density detection apparatus adjusts the toner density detection value based on a comparison between a first reference value stored in advance and the first digital data, and a comparison between a second reference value stored in advance and the second digital data.

Toner density detection apparatus and image forming apparatus having the same

An image forming apparatus that can realize an image having adequate image quality, density and color, without provoking excessive consumption of a developer and reduction in productivity. Image formation is performed by forming a latent image on an image carrier based on image information, then developing and transferring the latent image. An image for adjustment on a portion is formed other than a portion on which the latent image is formed on the image carrier. The density of the image for adjustment is detected. Image density is adjusted based on the density of the detected image for adjustment. Image formation control is executed whereby density is adjusted when an image is formed. A printing rate that indicates the percentage of the image formation to a sheet used for image formation is calculated. When the printing rate is determined to be within a set range, the image formation control is executed at a set frequency. On the other hand, when the printing rate is determined to be outside the set range, the set frequency is changed and the image formation control is executed.

Image formation control based on printing rate

An image forming apparatus forms an image by laser beams from a plurality of lasers. The image forming apparatus includes a light amount control circuit that detects displacement in a sub-scanning direction of the main scanning line of a laser beam from the predetermined laser, from a reference position. The apparatus decides an allotted amount of light for each of the plurality of lasers in accordance with the detected displacement and controls to drive each of the plurality of lasers in accordance with the decided allotted amount of light for each laser.

Image forming apparatus and control method therefor

An image forming system includes an image forming unit which forms an image as a toner image on a printing medium, a first fixing unit which fixes, on the printing medium, the toner image formed by the image forming unit, a second fixing unit arranged at a position different from the first fixing unit and used when a larger amount of heat is necessary for fixing the toner image on the printing medium, and a changing unit which changes the sequence of image formation by the image forming unit when the second fixing unit is used during image formation.

Image forming system and control method that change sequence of image formation based on fixation method

An image forming apparatus has a configuration in which a plurality of subsystems, each having a specific function, are interchangeably connected to a base platform. Each of the subsystems includes a plurality of units having a variety of different performances. A control unit is capable of control each of the subsystems so that the image forming apparatus flexibly provides functions that are tailored to individual users' requirements.

Image forming apparatus including an interchangeable engine and an interchangeable paper feeding and outputting system

An image forming apparatus includes a position detection circuit which detects the registration error amount between a recording medium conveyance unit and an image forming unit positioned by a positioning mechanism, on the basis of reading of a reference pattern arranged on either unit, and a controller which calculates a correction amount on the basis of the detected registration error amount and controls the operation timings of the image forming unit and recording medium conveyance unit in accordance with the correction amount.

In an image formation method of an image formation apparatus for correcting uneven image formation on the basis of vibration property information corresponding to an operation sequence in image formation, vibration property information corresponding to a plurality of operation sequences are stored in a storage device. The uneven image formation is corrected on the basis of vibration property information corresponding to an operation sequence selected from the storage device. Vibration property information generated by driving a movable member is measured when the selected operation sequence is being executed while correcting the uneven image formation. It is determined whether the measured vibration property information is similar to the vibration property information selected from the storage device. The vibration property information stored in the storage device is rewrite-controlled in accordance with the measurement result or the determination result.

Image formation apparatus and image formation method

A light source control apparatus for controlling the output of a light source for forming an electrostatic latent image on an image carrying member in an electrophotographic image forming apparatus, the light source control apparatus according to the present invention including a storing unit that stores first drive control data of the light source on two or more positions of the image carrying member, an interpolating that generates second drive control data on at least one interpolation position between the two or more positions based on the first drive control data, a digital-analog converting unit that converts the first and second drive control data to an analog signal, a low-pass filter that cuts a high-frequency component of the analog signal outputted from the digital-analog converting unit, and a driving unit that drives the light source in response to the analog signal from which the high-frequency component has been cut by the low-pass filter, wherein the low-pass filter has a cut-off frequency higher than a frequency for sampling on the two or more adjacent positions on the image carrying member and lower than a frequency for sampling on the two or more positions and the interpolation position.

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Toride, Japan

Shigeo Hata