Ricoh Company, Ltd.

Kunihiro Komai

Tatsuya Miyadera

Yoshinori Shirasaki

Akinori Yamaguchi

Takuhei Yokoyama

Takeshi Shikama

Izumi Kinoshita

Masayuki Hayashi

Hiroaki Ikeda

Motohiro Kawanabe

Fuminori Tsuchiya

Motoyoshi Takahashi

Yasuo Yamaguchi

Akira Yashiro

Takayuki Kawamoto

Katsuhiko Maeda

Susumu Miyazaki

Shinji Minami

An image forming apparatus includes a rotatable photoconductor, a charging device, a voltage applying device, a current detection device, and control circuitry. The control circuitry is configured to determine a film thickness of the photoconductor based on a charging current detected with the current detection device; determine an estimated film thickness of the film thickness, based on a previous film thickness and travel information of the photoconductor after determination of the previous film thickness; determine a discharging start voltage that the voltage applying device applies to start discharging from the charging device to the photoconductor; determine, from the estimated film thickness and the discharging start voltage, a film thickness determining voltage that the voltage applying device applies to pass a film thickness determining current being a charging current used for determining the film thickness; and apply the film thickness determining voltage to the charging device to determine the film thickness.

Image forming apparatus and image forming method

An optical writing device is configured to form electrostatic latent images on a plurality of photosensitive elements by a plurality of light sources. The optical writing device includes: an image-data acquiring section that acquires image data; and a light-source control section that performs light-emission control on the light source based on pixel data generated from acquired image data, and also performs a neutralization process on the photosensitive element by controlling the light source to expose the photosensitive element to light. In the neutralization process, the light-source control section divides a period during which light-on/off control can be performed on the light source, into sub-periods based on pixel data input to the light-source control section, and causes the light sources to be lit in any one of the sub-periods so as to always place at least one of the plurality of light sources in a light-off state.

Optical writing device, image forming apparatus, and method of controlling optical writing device

According to an embodiment, provided is an image forming device that includes: an image forming unit forming an image in a predetermined cycle in a direction orthogonal to a conveying direction of a printing medium; a velocity acquisition unit acquiring a conveying velocity of the printing medium at a position where the image is formed by the image forming unit; and a correcting unit correcting the cycle on which the image forming unit forms the image in accordance with the conveying velocity acquired by the velocity acquisition unit.

Image forming device and control method for image forming device

An optical writing device forms an electrostatic latent image and includes a pixel-information acquiring unit that acquires pixel information and stores the acquired pixel information in a storage medium with respect to each main scanning line; a tilt correcting unit that generates a tilt correction signal specifying a main scanning line from which the pixel information to be input to a light source is read out from the storage medium in order to correct a tilt of the electrostatic latent image; a position correcting unit that generates a position correction signal specifying a timing to input the pixel information to the light source in order to correct a position of the electrostatic latent image; and a pixel-information-input control unit that controls input of the pixel information from the storage medium to the light source in response to the tilt correction signal and the position correction signal.

Optical writing device, image forming apparatus, and method for controlling optical writing device

In the invention, an inclination amount of sensors is reflected in positional deviation correction patterns, and for correcting formation positions of images of various colors, the positional deviation correction patterns are formed on a conveying belt. The positional deviation correction patterns are detected by the sensors. A control unit calculates positional deviation correction amounts based on detection results of the positional deviation correction patterns. Based on the calculated positional deviation correction amounts, the control unit performs calculation for correcting the positional deviation correction patterns, and cancels the inclination amount reflected in the calculation results to obtain final positional deviation correction amounts. Skew correction is performed based on the final positional deviation correction amounts, and thus, the positional deviations are corrected.

Image forming apparatus and method for controlling the same

An aspect of the present invention provides an image forming apparatus including: a photosensitive element where a latent image is formed and developed into a toner image; an image carrier; an intermediate transfer driving roller that drives the image carrier; a primary transfer roller for transferring the toner image from the photosensitive element to the image carrier; a secondary transfer roller for secondary transfer of the toner image from the image carrier to a medium; a bias applying unit that applies, as a secondary transfer bias, a first bias and a second bias to the intermediate transfer driving roller and the secondary transfer roller, respectively; and a fixing unit that fixes the toner image onto the medium. The first bias is lower than a minimum voltage at which discharge to the primary transfer roller can occur. The second bias depends on the first bias and is opposite in polarity therefrom.

A light source control apparatus which controls, based on image data input, light emission of a light source which forms an electrostatic latent image on an image bearing body in an electrophotographic image forming apparatus is disclosed, including a pattern generating unit which generates an internal pattern for position aligning and concentration correcting according to the image data; and a mirroring processing unit which performs a process of mirroring the image data and the internal pattern at a later stage of the pattern generating unit.

Light source control apparatus and image forming apparatus

An optical writing device includes: a photosensitive element whose surface relatively moves with respect to a light source by rotation; a pixel information acquiring unit that acquires pixel information of an image to be formed on the photosensitive element as an electrostatic latent image; a line pixel information storing unit that stores the pixel information for every main scanning line; a light emission control unit that causes a light source to emit light based on the pixel information; a rotation position recognizing unit that recognizes a rotation position of the photosensitive element; and a light quantity control unit that controls a light quantity of the light source based on the pixel information of every one main scanning line in accordance with the rotation position, with reference to correction value information in which the rotation position and information related to a correction of the light quantity are associated.

Optical writing device having a correction value information generating unit, image forming apparatus, and method of controlling optical writing device thereof

An image forming apparatus can transfer a plurality of color component images onto a surface of a recording medium to form an image on the recording medium. The image forming apparatus includes a pattern generation part to generate information about an alignment pattern to be used for a calibration of an image forming, a plurality of stations each including a photosensitive drum to form an alignment pattern corresponding to each of a plurality of color components onto a carry belt or the recording medium, and a read part to detect a plurality of alignment patterns formed by the plurality of stations.

Image forming apparatus including image forming calibration

A power supply circuit includes a voltage regulator to which a first high voltage is supplied, to operate at constant voltage and regulate the supplied first high voltage, and a first rectifier circuit to which the first high voltage is supplied, connected in parallel to the voltage regulator, to rectify the supplied first high voltage for output as a first DC voltage. When the first high voltage is a pseudo-alternating-current (AC) voltage consisting of two types of high voltages that alternate, the voltage regulator regulates each of the two different types of the voltages to output a desired pseudo-AC voltage.

Power supply circuit, image forming apparatus incorporating same, and power supply method to supply voltage to image forming apparatus

A line-head control device that controls a line head includes: a calculation unit that divides image data into a plurality of areas in sub-scanning direction and calculates a printing percentage for each of the areas; an allocation unit that allocates a total correction amount, for correcting magnification of the image data in the sub-scanning direction, to the areas according to the printing percentage for each of the areas calculated by the calculation unit; and a control unit that changes an emission period of the light emitted from the line head so as to satisfy a partial correction amount that is an allocation of the total correction amount to each of the areas, exposes the image carrier to the light emitted from the line head with the changed light emission period, thereby causing a latent image to be formed on the image carrier based on the image data.

Line-head control device, image forming apparatus, and line-head control method

An apparatus to form plural images on an image conveyor includes plural photoconductor bodies, a light exposure device, a development device, a transfer device, and a pattern detection device, wherein the light exposure device includes an optical scanning part, a first light detection part having a first light receiving face, a second light detection part having a second light receiving face being non-parallel to the first light receiving face, a third light detection part having a third light receiving face being non-parallel to the first light receiving face, the optical scanning part, the first light detection part, and the second light detection part being provided inside a housing of the light exposure device, the third light detection part being provided outside the housing, and a light exposure timing control device.

Image forming method

A toner consumption calculator includes a plurality of line memories; a recorder that sequentially records image data including a plurality of pixels into the line memories; a skew correction unit that performs skew correction on the image data by sequentially reading the image data from the line memories while controlling read timing; and a counter that sequentially reads the image data from the line memories and counts toner consumption of a target pixel on the basis of light amounts of surrounding pixels of the target pixel.

Toner consumption calculator, image forming apparatus, and toner consumption calculation method

An image processing apparatus includes a reading part configured to optically read skew amount measurement patterns and opposite ends of a paper sheet; an image skew amount detecting part configured to detect skew amounts on a color basis based on the skew amount measurement patterns; a paper sheet skew amount detecting part configured to detect a skew amount of the paper sheet based on a displacement between the opposite ends of the paper sheet; a skew correction amount calculating part configured to calculate skew correction amounts of the respective colors based on the skew amounts; and a skew correcting part configured to shift the images to correct the skews by recording input image data in plural lines of a line memory, dividing the input image data into plural areas in a main scanning direction, and setting line delay amounts on an area basis based on the skew correction amounts.

Image processing apparatus, an image forming apparatus, an image processing method and a recording medium

An optical writing device forms an electrostatic latent image on a photosensitive element by a connected light source controlled by a light source control circuit that includes: a pixel data output unit; a pixel data correcting unit that corrects a skew between main scanning line of electrostatic latent image and photosensitive element and a local deviation of the electrostatic latent image on the main scanning line, and outputs pixel data; a pattern generating unit that outputs pixel data for forming a predetermined pattern in an electrostatic latent image; a first light source control unit for causing a first light source, that needs correction of the local deviation, to emit light; a second light source control unit for causing a second light source, that does not need correction of the local deviation, to emit light; and a switch that switches between a first transmission status and a second transmission status.

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Osaka, Japan

Kunihiro Komai