Sharp Kabushiki Kaisha Corporation

Masaaki Ohtsuki

Masatsugu Nakamura

Mitsuru Tokuyama

Mihoko Tanimura

Hirofumi Sakita

Norihide Yasuoka

Hiroshi Kawano

Takashi Kitagawa

Shinji Imagawa

Takeshi Murata

Kouji Shinkawa

Yoshinori Ohtsuka

Mihoko Okada

Hirohumi Sakita

A toner supply device for supplying toner to a developing device includes: a first toner supply portion for supplying toner to a developing hopper; a second toner supply portion for supplying the stored toner to the first toner supply portion; a first toner supply driver for driving the first toner supply portion; a first residual toner quantity detector for detecting the residual toner quantity in the first toner supply portion; a second toner supply driver for driving the second toner supply portion; a second residual toner quantity detector for detecting the residual toner quantity in the second toner supply portion; and a controller for controlling the drives of the first and second toner supply drivers by switching on and off the drives of the first and second toner supply drivers in accordance with the residual toner quantities detected by the first and second residual toner quantity detectors.

Toner supply device, developing device and image forming apparatus with residual quantity of toner based control

A small domain generation section generates a plurality of small domains in a multi-valued image transmitted from an intermediate tone correction section. Each domain is constituted of a plurality of pixels. Counting means counts a signal input value of each pixel. Weighting calculation means corrects each signal input value of the 'pixels subjection to toner quantity equivalent value calculation' with reference to the signal input value of the small domain, and reads out a weighting coefficient from the weighting coefficient table based on the modified signal input value. The weighting calculation means multiplies the signal input value by the coefficient so as to convert the signal input value into a toner quantity equivalent value. Accumulating means calculates toner quantity equivalent values for all of the pixels of the multi-valued image. A total toner quantity equivalent value calculation section determines a total toner quantity equivalent value by accumulating all of the toner quantity equivalent values which are individually calculated each time an image is processed. When the total toner quantity equivalent value reaches a predetermined value, conditions for process control is set. On this account, the present invention achieves an image forming apparatus capable of accurate estimation of toner consumption quantity.

Image forming electrophotography apparatus setting conditions for process control based on a total toner quantity equivalent value

An image processing device of the present invention is provided with four kinds of sub masks in total including two kinds in a main scanning direction and two kinds in a sub scanning direction, in a main mask constituted by a plurality of pixels including a target pixel. In the image display device, when determining a target pixel of an inputted image data, a difference in a total density of the two kinds of sub masks in a main scanning direction is added to a normalized difference in total density of the two kinds of sub masks in a sub scanning direction, and a resultant value is compared with a threshold value so as to determine if the target pixel is an edge area or not.

Image processing device for image region discrimination

An image processing device of the present invention includes a region separating section and a filter processing section. With respect to a picture signal which is read out after resolution thereof in a sub scanning direction has been converted, the region separating section computes maximum density difference and complexity as feature parameters indicative of a characteristic of each pixel in the picture signal. Additionally, with respect to the complexity which is dependent on a size of the resolution in the sub scanning direction, the region separating section carries out a correction in accordance with the size of the resolution in the sub scanning direction, and separates the picture signal into each region by using the maximum density difference and the corrected complexity. In accordance with the size of the resolution in the sub scanning direction and each region separated by the region separating section, the filter processing section performs suitable image processing of the picture signal.

Image processing device

The image forming device according to the present invention performs resolution conversion processing or scaling processing of a binary image and outputs a processed image. The present image forming device is provided with an edge detecting section, which, during resolution conversion or scaling of the binary image, detects edges of the image and detects lengths and shapes of the edges, and with an interpolated/skipped line producing section, which performs resolution conversion processing or scaling processing based on the lengths and shapes of edges detected by the edge detecting section.

Image forming device

An image forming apparatus of the present invention includes (i) an image interpolating section for calculating interpolation point and interpolation density of the interpolation point when subjecting a binary image to resolution conversion and scaling and (ii) an offset amount correcting section for giving an offset beforehand when the image interpolating section calculates the interpolation point. As a result, the image forming apparatus can comply with unrounded magnifications of other than integral multiples and a desirable image even with respect to a character image and a pseudo-halftone image.

Image forming apparatus

An image processing apparatus includes a pixel number transforming section for processing input image data composed of a plurality of regions, each being represented by a plurality of pixels with a pixel number transformation, by performing an interpolation or a decrimation on a pixel. It further includes a region decision value extracting section for extracting a region decision value of a region that a target pixel belongs to, based on characteristic amounts representing characteristics of a block composed of the target pixel and a plurality of pixels around the target pixel, each pixel of the image data being considered to be the target pixel. A controller controls a sequential order of a filtering process and pixel number transformation process to be applied to a region, based upon the transformation increasing or reducing a number of pixels in a region. Finally, a region decision value transforming section is included for calculating a region decision value of each region processed with the pixel number transforming process by an interpolation or a decrimation of the region decision value as extracted from the input image data.

Image processing apparatus

The read out image data is stored in the mask memory in a predetermined mask unit, and binarized into binary value with a predetermined threshold in the binarizing circuit. The binarized image data is output to the main scanning direction-black pixel counting circuit and the sub scanning direction-black pixel counting circuit, respectively, to count black pixels in the main scanning direction and in the sub scanning direction, respectively. The largest value is determined by the comparator, and designated as the linkage degree. With the judging circuit, the area judgement of the character area, the photograph area and the dot area is performed based on the linkage degree.

Area judging apparatus

The present invention relates to image forming device such as copying machines and laser printers, which use an electrophotographic (xerognaphic) process. A simple control method without using any additional complex means can equalize a surface potentional of a light-sensitive drum to keep a light-quality of an image formed even for the first rotation of the light-sensitive drum. A charge-removal prohibiting means, a charge-potentional changing means and a developing bias-potentional changing means are controlled in accordance with an extent of a change of a surface potential of a light-sensitive body, which depends upon a light fatigue and an ambient temperature of the light-sensitive body and/or a pause after a preceding image process.

Growing community of inventors

Yamatokoriyama, Japan

Masaaki Ohtsuki