US 8,554,094 B2 · Image forming apparatus and image quality control method

Abstract

Certain embodiments provide an image forming apparatus including a photoconductor, a latent image forming portion, an image processing portion, a developer, a transferred body, a sensor that detects an image density of a toner image by the amount of toner attached to a surface and has a sensor characteristic in which a sensor output substantially monotonously decreases according to an increase in the amount of toner, a nonlinear amplifier that has a nonlinear amplification characteristic having one or more inflection points, and enlarges and corrects a value read by the sensor in a range where the sensor output monotonously decreases with respect to the amount of toner by amplification, and an image quality control portion that controls a forming condition of an electrostatic latent image using a correction value of a variation amount of the value at a side where the amount of toner is large in the range.

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Drawings

Claims20

Dependent claims

An image forming apparatus comprising:

a photoconductor operable to rotate;
a latent image forming portion configured to electrically charge the photoconductor and forms an electrostatic latent image on a surface of the photoconductor;
an image processing portion configured to generate image data or pattern data;
a developer configured to develop the electrostatic latent image of the image data or the pattern data using toner;
a transferred body configured to have a surface onto which a toner image on the photoconductor is transferred;
a sensor configured to detect an image density of the toner image according to the amount of toner attached to the surface, and have a sensor characteristic in which a sensor output substantially monotonously decreases according to an increase in the amount of toner;
a nonlinear amplifier configured to have a nonlinear amplification characteristic having one or more inflection points, and enlarge and correct a value read by the sensor in a range where the sensor output monotonously decreases with respect to the amount of toner by amplification;
and
an image quality control portion configured to control forming conditions of the electrostatic latent image by the latent image forming portion, using a correction value of a variation amount of the value read by the sensor, the value being output from the nonlinear amplifier, at a side where the amount of toner is large in the range.

6 more elements

An image quality control method comprising:

developing an electrostatic latent image of image data or pattern data on a surface of a photoconductor using toner;
detecting an image density of a toner image based on the amount of toner, by a sensor having a sensor characteristic with a relationship between the amount of toner and a sensor output, the relationship being that the sensor output substantially monotonously decreases according to an increase in the amount of toner;
enlarging and correcting a value read by the sensor in a range where the sensor output monotonously decreases with respect to the amount of toner by amplification in a nonlinear amplifier which has a nonlinear amplification characteristic having one or more inflection points;
and
controlling forming conditions of the electrostatic latent image, by an enlarged variation amount of the value read by the sensor at a side where the amount of toner is large in the range.

2 more elements

Dependencies are inferred from the claim text.

Description6,482 words

Summary390 words

#Exemplary embodiments described herein relate to an image forming apparatus and an image quality control method.

#An image density of a toner image printed on a belt varies depending on circumstances such as temperature or humidity inside or outside an apparatus. The image density of a toner image indicates a value obtained by dividing the gross weight of toner on a region by the area of the region. An image forming apparatus maintains image quality such that the image density does not vary.

#The image forming apparatus patterns a toner image for density adjustment on the belt. The image forming apparatus detects an attached toner amount of the toner image using an optical sensor. The image forming apparatus detects the image density of the toner image based on the attached toner amount.

Brief description of the drawings15 figures

#FIG. 1 is a configuration diagram of an image forming apparatus according to a first embodiment;

#FIG. 2 is a diagram illustrating a configuration example of an image forming portion used in the image forming apparatus according to the first embodiment;

#FIG. 3A is a diagram illustrating a configuration example of a sensor used in the image forming apparatus according to the first embodiment;

Detailed description5,725 words

#Certain embodiments provide an image forming apparatus comprising: a photoconductor operable to rotate; a latent image forming portion configured to electrically charge the photoconductor and forms an electrostatic latent image on a surface of the photoconductor; an image processing portion configured to generate image data or pattern data; a developer configured to develop the electrostatic latent image of the image data or the pattern data using toner; a transferred body configured to have a surface onto which a toner image on the photoconductor is transferred; a sensor configured to detect an image density of the toner image according to the amount of toner attached to the surface, and have a sensor characteristic in which a sensor output substantially monotonously decreases according to an increase in the amount of toner; a nonlinear amplifier configured to have a nonlinear amplification characteristic having one or more inflection points, and enlarge and correct a value read by the sensor in a range where the sensor output monotonously decreases with respect to the amount of toner by amplification; and an image quality control portion configured to control forming conditions of the electrostatic latent image by the latent image forming portion, using a correction value of a variation amount of the value read by the sensor, the value being output from the nonlinear amplifier, at a side where the amount of toner is large in the range.

#Hereinafter, an image forming apparatus and an image quality control method will be described in detail using the accompanying drawings as examples. In addition, the same part is given the same reference numeral in each drawing, and repeated description will be omitted.

#First Embodiment

Facts

Application

13/170,041Filed 27 Jun 2011 · us provisional application

Priority

2 Jul 2010

Published

US 2012/0002991 A15 Jan 2012

Granted

8 Oct 2013

Term ends

8 Mar 2032

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 255 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification4 codes

G03G 15/5058
By measuring the characteristics of an intermediate image carrying member or the characteristics of an image on an intermediate image carrying…:…
G03G 2215/0132
The linear arrangement being horizontal or slanted: vertical medium transport path at the secondary transfer
G03G 2215/0164
Characterised by the technical problem: uniformity control of the toner density at separate colour transfers
G03G
Electrography

Timeline

2 Jul 2010Priority claimedParent application 61/361,362
27 Jun 2011Application filedUS 13/170,041
27 Jun 2011Assigned to Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaishaassignment of assignor's interest
5 Jan 2012PublishedUS 2012/0002991 A1
8 Oct 2013GrantedUS 8,554,094 B2
12 Oct 2026TodayWithin its term
8 Mar 2032Term endsEstimated, includes 255 days of adjustment

Image forming apparatus and image quality control method

Life of this patent

Image forming apparatus and image quality control method

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims20

Description6,482 words

Classification4 codes

Life of this patent

Drawings

Description6,482 words