Abstract: A belt drive control device of the present invention is constructed to sense the angular displacement or the angular velocity of a driven roller, separates from the angular displacement or the angular velocity sensed an AC component having a frequency that corresponds to the periodic thickness variation of an endless belt in the circumferential direction, and then controls the rotation of a drive roller in accordance with the amplitude and phase of the AC component.

Abstract: A device for driving an endless belt of the present invention includes a drive roller and a roller pair adjoining the drive roller at a side where a photoconductive element is positioned and contacting the belt. The eccentricity of the drive roller and that of the roller pair are reduced to reduce the variation of belt speed when the drive roller is controlled at a preselected angular velocity. Even when the drum is eccentric, the device stably operates integrally with the belt without any slip or oscillation.

Abstract: A belt drive control device constructed to sense the angular displacement or the angular velocity of a driven roller. The belt drive control device separates, from a sensed angular displacement or the angular velocity, an AC component having a frequency that corresponds to the periodic thickness variation of an endless belt in the circumferential direction, and then controls the rotation of a drive roller in accordance with the amplitude and phase of the AC component.

Abstract: An image formation apparatus is provided with a photosensitive drum, an optical writing device which writes an image on the outer surface of the photosensitive drum, a developing device which develops the image using toner an intermediate transfer belt onto which the toner image on the photosensitive drum is transferred, a rotation angle detection unit which detects the rotation angle of the photosensitive drum, an eccentric detection unit which detects the amount eccentricity of the photosensitive drum from the rotary axis of the photosensitive drum, and a correction unit which, obtains eccentricity of the photosensitive drum based on the amount eccentricity, the rotation angle and the radius of the photosensitive drum, and corrects a distortion and a color offset in the toner image based on the obtained eccentricity.

Abstract: A device for driving an endless belt of the present invention includes a drive roller and a roller pair adjoining the drive roller at a side where a photoconductive element is positioned and contacting the belt. The eccentricity of the drive roller and that of the roller pair are reduced to reduce the variation of belt speed when the drive roller is controlled at a preselected angular velocity. Even when the drum is eccentric, the device stably operates integrally with the belt without any slip or oscillation.

Abstract: An image forming apparatus of the present invention includes at least one rotatable image carrier, an image forming device for forming different images on the image carriers, a first image transferring device for transferring the images from the image carriers to a first image transfer body driven to move via a first image transfer position where it faces the image carriers, and a second image transferring device for transferring the resulting composite image from the first image transfer body to a second image transfer body driven to move via a second image transfer position where it faces the first image transfer body. The moving speed of each image carrier is equal to the moving speed of the second image transfer body. A period of time necessary for the surface of the first image transfer body to move from the first image transfer position to the second image transfer position is a natural number multiple of the period of speed variation occurring on the above surface.

Abstract: An image forming apparatus that reduces an influence of the variation of rotation speed of an image carrier, which is ascribable to, e.g., the eccentricity of a driven transmission member mounted on the image carrier, on the misregister of different colors. Further, the apparatus reduces the influence of the load variation of the image carrier acting on a transfer medium drive member on the misregister of different colors.

Abstract: An image formation apparatus is provided with a photosensitive drum, an optical writing device which writes an image on the outer surface of the photosensitive drum, a developing device which develops the image using toner an intermediate transfer belt onto which the toner image on the photosensitive drum is transferred, a rotation angle detection unit which detects the rotation angle of the photosensitive drum, an eccentric detection unit which detects the amount eccentricity of the photosensitive drum from the rotary axis of the photosensitive drum, and a correction unit which, obtains eccentricity of the photosensitive drum based on the amount eccentricity, the rotation angle and the radius of the photosensitive drum, and corrects a distortion and a color offset in the toner image based on the obtained eccentricity.

Abstract: An image forming apparatus that reduces an influence of the variation of rotation speed of an image carrier, which is ascribable to, e.g., the eccentricity of a driven transmission member mounted on the image carrier, on the misregister of different colors. Further, the apparatus reduces the influence of the load variation of the image carrier acting on a transfer medium drive member on the misregister of different colors.

Abstract: The optical disk is a data-writable optical disk and it has a defect processing selection area. Data indicating whether a defect processing is to be executed or not, or data indicating whether the defect processing is to be executed using a disk drive or using a computer is stored in the defect processing selection area. The address of this defect processing selection area is recorded by making the use of a wobbled guide groove.

Abstract: An image forming apparatus of the present invention is capable of reducing the influence of the variation of rotation speed of an image carrier, which is ascribable to, e.g., the eccentricity of a driven transmission member mounted on the image carrier, on the misregister of different colors. Further, the apparatus of the present invention reduces the influence of the load variation of the image carrier acting on a transfer medium drive member on the misregister of different colors.

Abstract: An image formation apparatus including at least one rotary member pressed onto the belt directly or indirectly and allowed to integrally rotate with the shift of the belt, a belt driving unit which moves the belt, or a rotary member driving unit which rotates the rotary member, and at least one of rotary member load correction unit for correcting variations in the load imposed on the rotary member and belt load correction unit for correcting variations in the load imposed on the belt.

Abstract: In an optical pickup method and device of the present invention, a grating unit separates a light beam, emitted by a light source, into a 0th order diffracted beam and 1st order diffracted beams. An objective lens focuses the diffracted beams, sent from the grating unit, onto a recording surface of an optical recording medium through a transparent substrate of the medium, so that a main spot is formed on the recording surface by the 0th order diffracted beam and sub-spots, interposing the main spot therebetween, are formed on the recording surface by the 1st order diffracted beams. A reflection beam detector receives reflection beams from the main spot and the sub-spots of the medium to generate detection signals from the received reflection beams.

Abstract: The object of the present invention is to provide an optical recording/reproducing method and apparatus that accurately record data blocks onto an optical disk in a seamless formation while effectively reducing the deterioration of recording properties of the disk. The recording properties of the disk may deteriorate when data is repeatedly written to a same data block of the disk. In the optical recording/reproducing method and apparatus of the invention, a read clock signal is generated in response to recorded data on an optical storage medium. A write clock signal is generated in response to a position information carrying signal detected from the storage medium. A phase difference between the read clock signal and the write clock signal is detected when writing data blocks to the storage medium in a seamless formation. It is determined whether a phase of the write clock signal is delayed or advanced based on the phase difference.

Abstract: An optical-pickup device includes a plurality of light sources, an objective lens for converging light from the plurality of light sources on an optical disc, and at least one light-receiving element for receiving light reflected by the optical disc. A light source of the plurality of light sources, which light source is not used for recording/reproducing, is used for detecting relative tilt between the optical disc and the objective lens.

Abstract: A belt drive control device of the present invention is constructed to sense the angular displacement or the angular velocity of a driven roller, separates from the angular displacement or the angular velocity sensed an AC component having a frequency that corresponds to the periodic thickness variation of an endless belt in the circumferential direction, and then controls the rotation of a drive roller in accordance with the amplitude and phase of the AC component.

Abstract: An image processor for a digital image of an object having a crack is disclosed, the digital image being made of a plurality of pixels. The image processor comprises a counter for counting a number of the pixels relating to the crack within a selected portion of the image, the selected portion being of a known area, an investigator for investigating the relationship among the pixels relating to the crack within the selected portion of the image, and a width evaluator for evaluating the width of the crack corresponding to the selected portion of the image on the basis of the number of the pixels and the relationship among the pixels.

Abstract: The optical disk is a data-writable optical disk and it has a defect processing selection area. Data indicating whether a defect processing is to be executed or not, or data indicating whether the defect processing is to be executed using a disk drive or using a computer is stored in the defect processing selection area. The address of this defect processing selection area is recorded by making the use of a wobbled guide groove.

Abstract: An image forming apparatus of the present invention includes at least one rotatable image carrier, an image forming device for forming different images on the image carriers, a first image transferring device for transferring the images from the image carriers to a first image transfer body driven to move via a first image transfer position where it faces the image carriers, and a second image transferring device for transferring the resulting composite image from the first image transfer body to a second image transfer body driven to move via a second image transfer position where it faces the first image transfer body. The moving speed of each image carrier is equal to the moving speed of the second image transfer body. A period of time necessary for the surface of the first image transfer body to move from the first image transfer position to the second image transfer position is a natural number multiple of the period of speed variation occurring on the above surface.

Abstract: An optical-pickup device includes a plurality of light sources, an objective lens for converging light from the plurality of light sources on an optical disc, and at least one light-receiving element for receiving light reflected by the optical disc. A light source of the plurality of light sources, which light source is not used for recording/reproducing, is used for detecting relative tilt between the optical disc and the objective lens.