Canon Kabushiki Kaisha

Threebond Co., Ltd.

Hidenori Kanazawa

Go Araki

Hisashi Ishikawa

Ryosuke Otani

Yoichi Takikawa

Takashi Kawana

Kenichi Fujii

Yuki Nakajima

Hiroyuki Yamazaki

Osamu Nagasaki

Hiroyuki Fukuhara

Shuhei Watanabe

Junya Kobayashi

Takaomi Uezono

Naoki Satou

Satoshi Matsuo

Kunihiko Kamata

Tomohiro Onoda

The present invention performs inplane uneven density correction that suppresses a number of tone correction properties and has few correction residuals. Accordingly, a holding unit of an apparatus of the present invention holds a plurality of tone correction properties respectively corresponding to a plurality of spot diameters that divide a range of a spot diameter of a light exposed on a surface of a photoreceptor by a predetermined interval. In addition a setting unit sets a tone correction property selected from the plurality of tone correction properties based on a spot diameter on the photoreceptor for a pixel corresponding to pixel data C. A correction unit corrects the pixel data C based on the set tone correction property, to generate tone correction data Cc.

Tone correction image processing based on pixel formation position on a photoreceptor

An image forming apparatus of the present invention acquires first correction characteristics representing an output density for an input gradation value at a reference position in a main scanning direction and second correction characteristics representing a relative relationship of an output density at a predetermined position in the main scanning direction with the output density at the reference position in the main scanning direction. Then, the image forming apparatus corrects image data corresponding to the predetermined position in the main scanning direction based on the first correction characteristics and the second correction characteristics.

Image forming apparatus and density correction method in image forming apparatus based on correction characteristics

In an image forming apparatus, a correction control unit of an image clock control unit controls the frequency of an image clock, so that the partial magnification of each position in an image region in which an image is formed is corrected in a main scanning direction that is a direction in which a laser beam scans a scanning region of one line. When controlling the frequency of the image clock, the correction control unit makes the change rate (the slope) that is a change amount of the image clock per unit time, be smaller in a non-image region being a region other than the image region, than the change rate in the image region.

Image forming apparatus

The present invention performs inplane uneven density correction that suppresses a number of tone correction properties and has few correction residuals. Accordingly, a correction unit corrects pixel data D based on a plurality of tone correction properties respectively corresponding to a plurality of spot diameters of a light to expose on a surface of a photoreceptor, and to generate a plurality of pieces of correction data Dand D. A setting unit sets a ratio Rb based on a spot diameter on the photoreceptor of a pixel corresponding to the pixel data D. A blending unit generates tone correction data Dc by blending the plurality of pieces of correction data Dand Dbased on the ratio Rb.

Image processing apparatus, method of controlling same, and image forming apparatus

An image forming apparatus includes: a photosensitive member; an exposure unit configured to divide one pixel into a plurality of pixel pieces and perform exposure on a pixel piece-by-pixel piece basis, to form an electrostatic latent image on the photosensitive member; a determination unit configured to determine, based on image data, an isolated pixel surrounded by blank pixels in the electrostatic latent image; a selection unit configured to select a correction target pixel from the blank pixels surrounding the isolated pixel; and a correction unit configured to correct the image data so as to expose a pixel piece of the correction target pixel.

Image forming apparatus that divides one pixel into plurality of pixel pieces and performs exposure on pixel piece-by-pixel piece basis

An image forming apparatus includes a reading unit for sequentially reading, from image data, pieces of pixel data of target pixels along a predetermined direction, a cumulative sum calculation unit for calculating a cumulative sum of gradation values represented by pieces of pixel data of target pixels in a significant image portion read by the reading unit, a determination unit for determining whether the target pixel read by the reading unit is located at a boundary between the significant image portion and a background portion that is a non-significant image portion, and a correction unit for correcting, if the determination unit determines that the target pixel is located at the boundary, a gradation value represented by pixel data of the target pixel by adding a correction amount based on the cumulative sum up to the target pixel calculated by the cumulative sum calculation unit to the gradation value.

Image formation with gradation value of boundary pixels corrected using cumulative sum of grataion values of pixels in significant image portion

There is provided an image forming apparatus comprising: a scanning unit configured to scan, in accordance with image signals, a photosensitive member with laser light in a main scanning direction at a scanning speed that is not constant; an image signal generation unit configured to generate image signals that are changed such that the faster the scanning speed is, the narrower an image signal width becomes; a clock signal generation unit configured to generate sampling clock signals for sampling the image signals whose image signal width is changed such that the faster the scanning speed is, the shorter a sampling interval becomes; and a count unit configured to count image signals whose image signal width is changed based on the sampling clock signals.

Image forming apparatus and method for counting image signals with changed image signal width

A scanning unit performs scanning over a photosensitive member with a laser beam irradiated from a light source. A width correction unit corrects exposure time. A luminance correction unit corrects luminance of the laser beam for forming latent images. A density correction unit corrects a density value of each of the pixels of the image data according to a scanning position of the laser beam on the surface of the photosensitive member.

Image forming apparatus that forms latent image by irradiating photosensitive member with light

An image forming apparatus includes: a scanning unit configured to form a latent image on a photosensitive member, wherein a scanning speed changes within a scan line; a control unit configured to perform correction control of a luminance and a light-emitting time of a light source; a holding unit configured to hold profile information indicating a change of the light spot due to an environment or due to a position of the pixel. The holding unit is further configured to hold scanning information indicating the light-emitting time of the light source or the luminance of the light source with respect to a pixel, for correcting a change in the scanning time of the pixel, and the control unit is further configured to perform the correction control based on the scanning information and the profile information.

Image forming apparatus and optical scanning apparatus for scanning photosensitive member with light spot

A pixel distance corrector configured to correct a pixel distance in the main scanning direction so that latent images corresponding to each pixel of image data are formed on the surface of the photosensitive member at substantially equal intervals in the main scanning direction. A controller configured to control a light source to emit light with a first light emission luminance with respect to an image part of the photosensitive member, and a second light emission luminance which is lower than the first light emission luminance, with respect to a non-image part of the photosensitive member. The controller is configured to correct light emission luminance so that the second light emission luminance decreases as the scanning speed decreases.

Image forming apparatus having light emission luminance based on scanning speed

An image forming apparatus includes: specifying unit configured to specify, based on image data, a pixel to be subjected to correction from among pixels of an image to be formed from the image data; and a correction unit configured to correct an exposure amount of an exposure unit for the pixel to be subjected to correction from an exposure amount indicated by the image data. The correction unit is further configured to correct the exposure amount applied by the exposure unit to the pixel to be subjected to correction by not exposing at least a portion of a region of the pixel to be subjected to correction according to the a distance between the pixel to be subjected to correction and an edge of the image to be formed from the image data.

Image forming apparatus and image processing apparatus that specify pixels to be subjected to correction, and correct exposure amount

An image forming apparatus includes: specifying unit configured to specify, based on image data, a pixel to be subjected to correction from among pixels of an image to be formed from the image data; and a correction unit configured to correct an exposure amount of an exposure unit for the pixel to be subjected to correction from an exposure amount indicated by the image data. The correction unit is further configured to correct the exposure amount applied by the exposure unit to the pixel to be subjected to correction by not exposing at least a portion of a region of the pixel to be subjected to correction according to the distance between the pixel to be subjected to correction and an edge of the image to be formed from the image data.

An aqueous coating composition having excellent coating adhesion, workability, heat resistance and chemical resistance, and has an object to provide an aqueous coating composition for sealing, which is suitable for members to be screwed in. An aqueous coating composition including: as main components, component (A) an ethylene-vinyl acetate copolymer resin emulsion and component (B) two or more PTFE resin powders having different particle diameters, in which 35 to 80 parts by mass of water is contained on the basis of 100 parts by mass of the total of (A) and (B).

Aqueous coating composition

A composition for use as a self-locking agent is provided which comprises an aqueous dispersion of the following ingredients dissolved and dispersed in water: (a) a polyamide powder insoluble or slightly soluble in water, (b) an isocyanate compound, (c) a surfactant and (d) a water-soluble polyamide. The composition permits a polyamide resin layer of a smooth surface to be formed on a screw surface of a to-be-coated member. With use of the composition, it is possible to prevent slippage and sagging of the resin layer coated on the screw surface and improve the precision in resin coating processing.

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Mishima, Japan

Hidenori Kanazawa