Electrophotography – Control of electrophotography process – Control of developing
Reexamination Certificate
1999-12-27
2001-05-08
Chen, Sophia S. (Department: 2852)
Electrophotography
Control of electrophotography process
Control of developing
C118S690000, C399S053000, C399S060000
Reexamination Certificate
active
06229971
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present Invention generally relates to toner concentration control technique for use in electrophotographic equipment.
2. Description of the Related Art
There has been proposed a toner concentration detection technique making use of electric conductivity of liquid developer in Japanese Patent Unexamined Publication No. 3-295453. The electric conductivity is measured using alternating current because direct current measurement causes movement of ionic carriers and polarization by which voltage drops are caused around electrodes. The measurement frequency is determined depending on the frequency response of the object. In the case of liquid developer, a frequency of 1 kHz may be preferably used.
However, there occurs an increase in the number of ionic contaminants or the like due to deterioration of liquid developer. Such ionic contaminants or the like become a factor that substantially influences the measurement, resulting in a lower degree of measurement accuracy.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a toner concentration detecting method and system which can measure the toner concentration with high accuracy.
Another object of the present invention is to provide a toner concentration controller which can keep the toner concentration optimally.
According to the present invention, a developing current flowing when the developing process is performed is used to estimate the toner concentration. A method for detecting a toner concentration of a developer including toner particles, comprises the steps of: developing a latent image having a predetermined area formed on a photoconductor using a developing member to move toner particles from the developing member to the photoconductor; detecting a developing current flowing through the developing member when the latent image is developed; and calculating the toner concentration based on the developing current and a toner developed area of the latent image.
The toner concentration may be calculated using a predetermined relationship among a developing current, a toner concentration, and a toner developed area of a latent image.
According to an aspect of the present invention, the latent image is a predetermined Image pattern having a predetermined toner developed area. The toner concentration may calculated using a predetermined relationship between a developing current and a toner concentration when the latent image has the predetermined toner developed area.
According to another aspect of the present invention, a toner developed area of the latent image is obtained by counting toner dots included in the predetermined area based on image data which is used to form the latent image on the photoconductor. The toner concentration may be calculated using a predetermined relationship among a developing current, a toner concentration, and a toner developed area of a latent image.
As described above, a developing current flowing on the developing process is detected and is used to estimate the toner concentration. Therefore, the toner concentration can be obtained accurately. For example, the measurement of the toner concentration is unaffected by an increase in the number of ionized impurities or the like due to deterioration of liquid developer.
REFERENCES:
patent: 4492179 (1985-01-01), Folkins et al.
patent: 4536082 (1985-08-01), Motohashi et al.
patent: 4786924 (1988-11-01), Folkins
patent: 5034775 (1991-07-01), Folkins
patent: 5150135 (1992-09-01), Casey et al.
patent: 5416564 (1995-05-01), Thompson et al.
patent: 5521683 (1996-05-01), Miyamoto et al.
patent: 61-153677 (1986-07-01), None
patent: 1-217377 (1989-08-01), None
patent: 3-75674 (1991-03-01), None
patent: 3-295453 (1991-12-01), None
patent: 4-170558 (1992-06-01), None
patent: 4-204878 (1992-07-01), None
patent: 5-224534 (1993-09-01), None
patent: 8-146775 (1996-06-01), None
Chen Sophia S.
NEC Corporation
Ngo Hoang
Young & Thompson
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