JPH11258873A5

JPH11258873A5 - Image forming device

Info

Publication number: JPH11258873A5
Application number: JP1998062966A
Authority: JP
Filing date: 1998-03-13
Publication date: 2005-08-18

Description

【０００２】
【発明の属する技術分野】
この発明は、たとえばカラーレーザプリンタやカラーデジタル複写機などの電子写真式の画像形成装置に関する。 [0002]
[Technical Field to which the Invention Belongs]
The present invention relates to an electrophotographic image forming apparatus such as a color laser printer or a color digital copier.

そこで、比較的容易にかつ短時間で画質制御を行うことができ、開発効率の向上、メモリ容量の低減による製造コストの低減、更に、固体間差、再現性、経年変化に応じて適切な画質維持が可能な画像形成装置を提供することを目的とする。 Therefore, the object is to provide an image forming apparatus that can perform image quality control relatively easily and in a short time, improves development efficiency, reduces manufacturing costs by reducing memory capacity, and further, can maintain appropriate image quality in accordance with individual differences, reproducibility , and changes over time.

【０２５６】
【発明の効果】
以上詳述したようにこの発明によれば、比較的容易にかつ短時間で画像濃度の最適な制御を行うことができ、開発効率の向上、メモリ容量の低減による製造コストの低減、更に、固体間差、再現性、経年変化に応じて適切な画質維持が可能な画像形成装置を提供することができる。 [0256]
[Effects of the Invention]
As described above in detail, according to the present invention, it is possible to provide an image forming apparatus that can perform optimal control of image density relatively easily and in a short time, improve development efficiency, reduce manufacturing costs by reducing memory capacity, and further maintain appropriate image quality in accordance with individual differences, reproducibility, and changes over time.

Claims

an image forming means for forming a developer image on an image carrier based on image data;
a detection means for detecting the image quality of the image formed on the image carrier;
a plurality of operation means for adjusting the image quality formed on the image carrier;
a deviation calculation means for calculating a control amount deviation between the image quality detected by the detection means and a preset image quality;
a control means having a determination means for determining whether the calculated control amount deviation is within a predetermined allowable range , a selection means for selecting an operation means for correcting the calculated control amount deviation when the deviation exceeds the allowable range, a sensitivity detection means for detecting the sensitivity of the control amount deviation to the operation amount of the operation means by test-adjusting the image quality using the selected operation means , an operation amount determination means for determining an adjustment operation amount of the corresponding operation means in accordance with the detected sensitivity , and a means for operating the corresponding operation means in accordance with the determined operation amount to correct the deviation;
An image forming apparatus comprising:

an image forming means for forming a developer image on an image carrier based on image data;
a detecting means for detecting the image density of the developer image formed on the image carrier;
a plurality of operating means for adjusting the image density of the developer image formed on the image carrier;
a deviation calculation means for calculating a control amount deviation between the image density detected by the detection means and a preset image density;
a control means having a determination means for determining whether the calculated control amount deviation is within a predetermined allowable range , a selection means for selecting an operation means for correcting the calculated control amount deviation if the deviation exceeds the allowable range, a sensitivity detection means for test-adjusting the image quality using the selected operation means to detect the sensitivity of the control amount deviation to the operation amount of the operation means , an operation amount determination means for determining an adjustment operation amount of the corresponding operation means in accordance with the detected sensitivity , and a means for operating the corresponding operation means in accordance with the determined operation amount to correct the deviation;
An image forming apparatus comprising:

3. The image forming apparatus according to claim 1, wherein the control means further repeats the judgment, selection of the operation means, sensitivity detection, operation amount determination, and correction until all deviations converge within the allowable range.

4. The image forming apparatus according to claim 1, wherein the control means has an adjustment rule generating means for generating an adjustment rule indicating a priority of the operation amounts based on a dependency between the operation amounts of each of the operation means and the control amount deviation, and the selection means selects the operation means in accordance with the adjustment rule.

a charging means for charging the image carrier using a grid;
a first applying means for applying a grid bias voltage to the grid;
generating means for generating a high density test pattern and a low density test pattern having a density lower than that of the high density test pattern;
a latent image forming means for forming a latent image on the image carrier charged by the charging means based on the high-density test pattern and the low-density test pattern generated by the generating means;
a developing means for developing the latent image formed on the image carrier by the latent image forming means with a developer;
a second applying means for applying a developing bias voltage to the developing means;
a holding means for holding a contrast voltage, which is a relationship between an exposed portion potential and a developing bias voltage value, and a background voltage, which is a relationship between an unexposed portion potential and a developing bias voltage value, when the test pattern is formed on the image carrier;
a developer adhesion amount measuring means for measuring a high density portion of the amount of developer adhesion for a high density test pattern developed on the image carrier by the developing means and a low density portion of the amount of developer adhesion for a low density test pattern;
a setting unit that sets target values for the amounts of developer adhered to the high-density and low -density portions; and a deviation calculation unit that calculates a deviation between the high-density and low -density portions based on the target values for the amounts of developer adhered to the high-density and low -density portions set by the setting unit and the amounts of developer adhered to the high-density and low -density portions.
a control means for repeating the judgment, selection of the operating means, sensitivity detection, operation amount determination, and correction until all deviations converge within the allowable range; a judgment means for judging whether the deviation between the high density portion and the low density portion calculated by the calculation means is within an allowable range; a selection means for selecting an applying means from the first and second applying means for correcting the detected deviation if the deviation exceeds the allowable range; a sensitivity detection means for test-adjusting the grid bias value or the developing bias value by the selected applying means to detect the sensitivity of the controlled variable deviation to the adjustment operation amount of the applying means ; an operation amount determination means for determining the adjustment operation amount of the corresponding applying means in accordance with the detected sensitivity; and a control means for adjusting the grid bias value or the developing bias value by the corresponding applying means in accordance with the determined operation amount to correct the contrast voltage and background voltage for the deviation between the high density portion and the low density portion.
An image forming apparatus comprising:

6. The image forming apparatus according to claim 5 , wherein the developer adhesion amount measuring means measures the amount of reflected light from the high density portion, the amount of reflected light from the low density portion, and the amount of reflected light from the image carrier.

6. The image forming apparatus according to claim 5 , wherein the operating means changes the developing bias voltage after a predetermined time has elapsed after the grid bias voltage has been changed.

8. The image forming apparatus according to claim 5, wherein the control means has an adjustment rule generating means for generating an adjustment rule indicating a priority of the operation amounts from a dependency relationship between the operation amounts of each of the operation means and the control amount deviation , and the selection means selects the operation means in accordance with the adjustment rule.

a pattern generating means for generating a high density test pattern and a low density test pattern having a density lower than that of the high density test pattern;
an exposure means for forming a latent image on an image carrier based on the high-density test pattern and the low-density test pattern generated by the pattern generating means, and for controlling the exposure amount in accordance with target exposure amount information;
a developing means for developing, with a developer, the latent images of the high-density test pattern and the low -density test pattern formed on the image carrier by the exposure means;
a developer adhesion amount measuring means for measuring the amounts of developer adhered to the high-density test pattern and the low -density test pattern adhered to the image carrier by development by the developing means;
a light emission time correction means for correcting a light emission time per unit pixel based on light emission time correction information for the gradation data per unit pixel of the image data;
modulation control means for modulating and controlling the exposure means as a pulse width per unit pixel based on the light emission time information corrected by the light emission time correction means;
deviation calculation means for calculating deviations between the measured values of the high density portion and the low density portion measured by the developer adhesion amount measurement means and respective target values set in advance;
a control means having a determination means for determining whether each deviation calculated by the deviation calculation means is within an allowable range , a selection means for selecting a means for correcting the calculated deviation from the light emitting time correction means and the modulation control means when the determination means determines that the deviations are not within the allowable range, a sensitivity detection means for detecting the sensitivity of the deviation control amount to an adjustment operation amount by test adjusting the developer adhesion amount using the selected light emitting time correction means and modulation control means, an operation amount determination means for determining the adjustment operation amount of the light emitting time correction means and the modulation control means in accordance with the detected sensitivity , and a means for operating the light emitting time correction means and the modulation control means in accordance with the determined operation amount to correct the deviations, and repeating the determination, selection of the operation means, sensitivity detection, operation amount determination, and correction until all deviations converge to the allowable range;
An image forming apparatus comprising: