摘要:
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.
摘要:
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.
摘要:
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.
摘要:
An image forming apparatus with an image adjusting function using a adjustment patterns transferred on an endless belt including; a calculation unit that obtains, based on the measured positions of the adjustment patterns, a deviation in a rotating direction and/or in a width direction, respectively; and an adjustment unit that adjusts an image to be formed based on each obtained deviation, the adjustment patterns including a first oblique pattern obliquely intersecting with one straight line extending in the width direction of the endless belt in a right front direction and a second oblique pattern obliquely intersecting with the line in a left front direction, the calculation unit obtaining the deviation in the rotating direction from an average of the deviations of the first and second oblique pattern in the rotating direction and obtaining the deviations of the first and second oblique pattern in the width direction, respectively.
摘要:
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+α)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.
摘要:
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.
摘要:
In an image forming apparatus, a computing unit computes phase shift amounts A(i) for every correction relative phase angle θ(j) based on an amplitude B of a reference compressional wave αa, an amplitude C(i) of a detection compressional wave α(i), and a relative phase angle φ(i). A setting unit specifies the phase shift amounts A(i), and sets a correction relative phase angle θ(j) corresponding to the specified phase shift amounts A(i). A correction unit corrects, based on the correction relative phase angle θ(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.
摘要:
In an image forming apparatus, a computing unit computes phase shift amounts A(i) for every correction relative phase angle θ(j) based on an amplitude B of a reference compressional wave αa, an amplitude C(i) of a detection compressional wave α(i), and a relative phase angle φ(i). A setting unit specifies the phase shift amounts A(i), and sets a correction relative phase angle θ(j) corresponding to the specified phase shift amounts A(i). A correction unit corrects, based on the correction relative phase angle θ(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.
摘要:
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.
摘要:
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.