Sharp Kabushiki Kaisha Corporation

Yoshikazu Harada

Norio Tomita

Toshio Yamanaka

Kyosuke Taka

Nobuo Manabe

Yoshiteru Kikuchi

Tetsushi Ito

Hideaki Kadowaki

Ayumu Oda

Kengo Matsuyama

Kenichi Isomi

Yoshiharu Yoneda

Yasuji Yamauchi

Yasuo Kitabatake

Tetsuya Yamaguchi

Showtaro Okamoto

Hiroshi Tachiki

Takaharu Motoyama

Hidekazu Sakagami

Takayuki Ohno

Kenji Tanaka

Eiichi Kido

Toshiaki Ino

Tadasu Taniguchi

Hirokazu Fujita

Masaki Amemiya

Manabu Matsumoto

Noriaki Taguchi

Kohichi Yamauchi

Masanobu Yamamoto

Mitsuyoshi Terada

Takashi Makiura

Yuji Kumagai

Takahiko Yoshida

Hiroshi Naka

Hiroaki Uchiyama

Kazunobu Takahashi

Koichi Nakamura

Shinichi Yamane

Yasuji Nakahama

Koichi Yamauchi

Shoichi Fukutome

Daisuke Shige

Eiji Kamimura

Yutaka Eba

A set of adjustment pattern images includes first adjustment pattern images and second adjustment pattern images to be formed on a first side and a second side of a recording sheet, respectively, by an image forming apparatus. The set of adjustment pattern images is employed to adjust an image forming position by the image forming apparatus such that an image forming position of the first adjustment pattern images is aligned with an image forming position of the second adjustment pattern images. The set of adjustment pattern images includes at least two first adjustment pattern images that are spaced from each other and at least two second adjustment pattern images that are spaced from each other, and the first adjustment pattern images on the first side and the second adjustment pattern images on the second side are arranged alternately with each other.

Image forming apparatus, image adjustment method for the image forming apparatus, and adjustment pattern image

A floor type multi-display apparatus includes a multi-display, transparent panels, and a plurality of support members. The multi-display includes a plurality of displays. The support members include first support members disposed between adjacent ones of the displays in a scattered fashion, and second support members disposed around the multi-display. The support members have respective plate portions positioned along and closely to edges of the displays. The support portion and the base portion of each of the first support members project toward two displays located closely thereto from the plate portion of the first support member. The support portion and the base portion of each of the second support members project toward only one display located closely thereto from the plate portion of the second support member.

Floor type multi-display apparatus and floor structure for installation of a floor type multi-display apparatus

An image forming apparatus including: an output image forming section for forming an image and a pattern on a supporting medium under a prescribed condition; an output section for transferring the formed image on a recording sheet; a correction section for performing reading of the formed pattern and correcting the condition based on a result of the reading; and a correction control section for controlling operations of the output image forming section, the output section, and the correction section, wherein the correction control section identifies whether or not an area where the image is to be formed and an area where the pattern is to be formed overlap each other, and when the areas are identified that they do not overlap each other, the correction control section controls the output image forming section to simultaneously form the image and the pattern in parallel on the supporting medium.

Image forming apparatus

In an image forming apparatus, a computing unit computes phase shift amounts A(i) for every correction relative phase angle &#x3b8;(j) based on an amplitude B of a reference compressional wave &#x3b1;a, an amplitude C(i) of a detection compressional wave &#x3b1;(i), and a relative phase angle &#x3c6;(i). A setting unit specifies the phase shift amounts A(i), and sets a correction relative phase angle &#x3b8;(j) corresponding to the specified phase shift amounts A(i). A correction unit corrects, based on the correction relative phase angle &#x3b8;(j) set by the setting unit, a relative phase shift between a periodic variation in the circumferential speed of a first image bearing member and a periodic variation in the circumferential speed of a second group image bearing member by operationally controlling at least one of first and second drive units.

An LD switch is turned ON to output image data outputted from an image processing section to a laser diode, and to irradiate a laser light to a photosensitive drum. The number of pixel dots included in the image data outputted from the image processing section is computed by line basis to detect an image density based on the total sum of the pixel dots of each color at a timing when the image data of Nth line is outputted from the image processing section. The detected image density is compared with a threshold value to turn OFF the LD switch at a timing when the image data of (N+&#x3b1;)th line is outputted when the image density is greater than the threshold value. This suppresses a variation in a rear-end-void length due to sheet slippage.

Image forming apparatus and image forming method with sheet slip compensation

In an embodiment of the present invention, an image forming apparatus includes a transfer belt that primarily transfers a toner image formed on a photosensitive drum; a secondary transfer unit including a transfer mechanism portion that secondarily transfers the primarily transferred toner image to a paper; an optical sensor that detects a reference toner image on the transfer belt; and a shutter that protects a detection face of the optical sensor, wherein a separation/contact mechanism portion disposed so as to be brought into contact with both of the shutter and the secondary transfer unit is provided, and the separation/contact mechanism portion allows the shutter to move so as to open and allows the secondary transfer unit to move so as to separate from the transfer belt when the reference toner image is detected by the optical sensor, and allows the shutter to move so as to separate from the transfer belt when the secondary transfer unit is drawn out from an apparatus main body.

Intermediate transfer-type image forming apparatus with separation/contact mechanism

There is provided an image forming apparatus that includes couplings for photoreceptor drums, couplings for waste toner transporting screws, and couplings for developing rollers, that transmit driving force to each of a plurality of driving shafts for driving a process portion that performs image formation by an electrophotographic method, and a plurality of coupling attaching/detaching members for attaching/detaching the plurality of coupling members, so as to drive the process portion. In the image forming apparatus, the plurality of coupling attaching/detaching members are provided so as to be movable independently, and the image forming apparatus includes a coupling attaching/detaching member driving mechanism that operates the coupling attaching/detaching members in association with each other.

Coupling mechanism for a process portion of an image forming apparatus

An image forming apparatus includes a controller for detecting the opening and closing of a shutter from the output from an optical sensor and controlling the opening and closing operation of the shutter based on the detected result. The controller determines that if the optical sensor is turned 'ON' within a predetermined period of time from when the shutter begins opening, the operation of the shutter from the closed state to the open state is correctly detected. When no reflected light is detected by the optical sensor even after a predetermined time has elapsed, the controller determines that an anomaly has occurred and closes the shutter and repeat another detecting process.

Multiple photoconductive drums on which images with different color components are formed respectively are rotated using individual motors, multiple adjustment images are formed at a predetermined interval along the cycle length of one rotation of each photoconductive drum, the reference phases for the rotation of the respective photoconductive drums are determined based on the maximum portions of the divergences between the predetermined interval and the detection interval of each adjustment image, and the individual motors are controlled so that the respective reference phases determined are aligned. The image forming region corresponding to the cycle length of one rotation of the photoconductive drum is divided into four or more even-numbered regions, the divergence amount of each region is calculated, and the maximum portions of the divergences are determined based on the difference between the divergence amounts of the divided regions being away from each other by a half cycle length.

Image forming apparatus and image forming adjustment method

An image forming apparatus include: a plurality of photosensitive drums; a latent image forming unit for forming an electrostatic latent image on each photosensitive drum; a developing unit for developing each electrostatic latent image; a transferring unit for superimposing and transferring the developed images onto a moving record medium; a measurement unit for measuring positions of the transferred images on the record medium; and a control unit for controlling the photosensitive drums, the latent image forming unit, the developing unit, and the transferring unit. The control unit includes: a calculating unit for calculating a value related to alignment errors in the positions measured by said measurement unit in accordance with a sine-curve fitting method; and a correcting unit for correcting the alignment errors by the calculated value.

Alignment error correcting unit for image forming apparatus

A color registration method in a color image forming apparatus including a plurality of drum-type photoconductors for driving some or all of the photoconductors having the same diameter to match pitch fluctuations which correspond to a rotational cycle of the photoconductors, the method including: a first measurement step for forming a first registration image for each color and measuring formation positions of a plurality of predetermined portions in each registration image; a second measurement step for forming a second registration image for each color and measuring formation positions of a plurality of predetermined portions in each registration image; a calculation step for calculating a periodic fluctuation component being contained in the images in different colors and corresponding to the rotational cycle of the photoconductors so as to obtain phases thereof; and a step for adjusting a rotational phase of the photoconductors in order for the obtained phases matching to each other, wherein the interval between first and second registration images in the rotating direction is set such that disturbance components in which a cycle is assumed beforehand, cancel with each other by calculating the deviation.

Color registration method and image forming apparatus

It is an object to prevent distortions and deviations of images caused by the eccentricity of a driven gear mounted to a rotational shaft of a photosensitive drum. There are provided a driving gear which is secured to a rotational shaft of a rotational driving power source and is rotated at a constant peripheral speed, a driven gear secured coaxially to a rotational shaft of a cylindrical-shaped photosensitive member, a phase control gear having the same diameter as that of the driven gear and having the same rotational speed variation characteristic as that of the driven gear, and a transmission gear, and a driving force from the driving gear is transmitted to the driven gear through the phase control gear and the transmission gear.

Photosensitive-member driving mechanism

An image forming apparatus includes an image forming unit that forms a color image in which a plurality of color component images are superimposed; and a formation controlling unit that allows the image forming unit to form images for adjustment of formation positions of the respective color component images. The formation controlling unit allows the image forming unit to form, for each color, a plurality of adjustment images having different tilts with respect to a main scanning direction. A shift of a detected position of each adjustment image from a reference position in which each adjustment image should be formed is calculated, a tilt and an intercept of a regression line that uses the reference positions and the calculated shifts as variables are calculated, and a shift in the main scanning direction and a shift in a sub-scanning direction are determined based on the calculated tilt and intercept.

Image forming apparatus and method of adjusting color shift

An image forming apparatus including: image forming sections, each image forming section forming an image of a color component among plural color components under a predetermined condition, and forming a pattern of each color component for adjusting the condition; a detecting section that reads the formed patterns so as to perform a temporary detection and a main detection of a deviation from a reference under the condition; and a correction control section that determines whether the deviation of the temporary detection exceeds a predetermined threshold value or not, and when the deviation exceeds the threshold value, executes the main detection to fully detect the deviation so as to correct the condition, wherein the correction control section controls to form the pattern for the temporary detection, the number of the color components for the temporary detection being fewer than those of the patterns to be used for the main detection.

Image forming apparatus and correction method of image forming condition

A color image forming apparatus including: a plurality of drum-type photoconductors for forming an image in a different color on each peripheral surface and the photoconductors having at least two different diameters; a plurality of driving sections for driving each photoconductor at a driving speed in accordance with the diameter so that each photoconductor rotates at a predetermined peripheral speed; a correction signal output section for outputting a speed correction signal to correct a periodic pitch fluctuation included in each formed image; and a drive control section for controlling the driving section to correct the driving speed of each photoconductor by the speed correction signal, wherein the speed correction signal is a signal having the same cycle as a rotational cycle of each photoconductor.

Growing community of inventors

Nara, Japan

Yoshikazu Harada