Image density control method
AssigneeRicoh Company, Ltd.
InventorsKazuo Murai, Yutaka Hasegawa
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Abstract
An image density control method for an electrophotographic apparatus is disclosed which prepares a white pattern region and a black pattern region on a photoconductive element whose electrostatic latent images are far different from each other in potential. Values relating to image densities individually associated with the two pattern regions are sensed and, based on the sensed values, parameters relating to image processing which effect image density are controlled. When any of the sensed values does not lie in a predetermined range, it is suitably compensated.
Claims14
A method of controlling a density of an image formed by developing an electrostatic image on a photoconductive element by means of a toner, said method comprising the steps of:
- (a) providing at least two regions for independent test patterns which are different from each other as latent images electrostatically formed on a photoconductive element;
- (b) sensing a value relating to an image density in each of the two pattern regions;
- (c) compensating the sensed value relating to the image density in each of the pattern regions when said value is out of a predetermined range;
- and
- (d) controlling an image density parameter relating to image precessing which has influence on image density, in response to the values relating to the image densities which are representative of the two pattern regions respectively;
- step (c) comprising a step of (e) interrupting a control over the image density parameter.
A method of controlling a density of an image formed by developing an electrostatic image on a photoconductive element by means of a toner in a developer, said method comprising the steps of:
- (a) providing at least two regions for independent test patterns which are different from each other as latent images electrostatically formed on a photoconductive element;
- (b) sensing a value relating to an image density in each of the two pattern regions;
- (c) performing primary toner supply to the developer in accordance with a number of electrostatic images developed by the toner;
- and
- (d) performing secondary toner supply to the developer in response to the values relating to the image densities which are representative of the two pattern regions respectively.
A method of controling a density of an image formed by developing an electrostatic image on a photoconductive element by means of a toner, said method comprising the steps of:
- (a) providing at least two regions for independent test patterns which are different from each other as latent images electrostatically formed on a photoconductive element, the pattern regions comprising a white pattern region and a black pattern region;
- (b) sensing an image density in each of the two pattern regions;
- (c) producing values relating to the image densities by multiplying the sensed image density of the black pattern region by a constant value which is predetermined in such a manner that the value relating to the image density of the black pattern region will be approximately equal to the value relating to the image density of the white pattern region;
- and
- (d) controlling an image density parameter relating to image processing which has influenece on image density, in response to the values relating to the image densities which are representative of the two pattern regions respectively.
Dependencies are inferred from the claim text.