Image forming apparatus that controls image forming conditions for adjusting image density

Patent metadata

Field	Value
Publication number	US-9819826-B2
Application number	US-201615235780-A
Country	US
Kind code	B2
Filing date	Aug 12, 2016
Priority date	Sep 7, 2015
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

An image forming apparatus includes: an output unit configured to receive light reflected from a measurement image on an image carrier and output a signal corresponding to a light receiving result; a detection unit configured to detect a temperature of the output unit; a conversion unit configured to convert an output value output from the output unit, based on a conversion condition; a controller configured to control an image forming condition for adjusting a density of an image to be formed based on a converted output value by the conversion unit; and a generation unit configured to, at a predetermined timing, acquire an output value output from the output unit without emitting light, control the detection unit to detect the temperature, and generate the conversion condition based on the acquired output value and the detected temperature.

First claim

What is claimed is:

1. An image forming apparatus comprising:
an image carrier;
an image forming unit configured to form an image on the image carrier;
a light emitting unit configured to emit light;
an output unit configured to receive light reflected from a measurement image on the image carrier and output a signal corresponding to a light receiving result;
a detection unit configured to detect a temperature of the output unit;
a conversion unit configured to convert an output value output from the output unit, based on a conversion condition;
a controller configured to control an image forming condition for adjusting a density of an image to be formed by the image forming unit, based on a converted output value by the conversion unit; and
a generation unit configured to, at a predetermined timing, acquire an output value output from the output unit without the light emitting unit emitting light, control the detection unit to detect the temperature of the output unit, and generate the conversion condition based on the acquired output value and the detected temperature.

2. The image forming apparatus according to claim 1 , wherein
the conversion condition is a condition that is based on a relation between the output value from the output unit when the light emitting unit is not emitting light and the temperature of the output unit, and
the generation unit generates the conversion condition by polynomially approximating the detected temperature and the acquired output value at the predetermined timing, at a plurality of predetermined temperatures in the relation and a plurality of output values that correspond to the plurality of predetermined temperatures, and updating the relation with the polynomial used in the approximation.

3. The image forming apparatus according to claim 2 , further comprising:
a temperature control unit configured to control a temperature of the image forming apparatus to be in a predetermined temperature range,
wherein the plurality of predetermined temperatures are temperatures selected from temperatures outside the predetermined temperature range and temperatures that are an upper limit and a lower limit of the predetermined temperature range.

4. The image forming apparatus according to claim 1 , wherein a frequency of the predetermined timing is less than a frequency at which the controller controls the image forming condition.

5. The image forming apparatus according to claim 1 , wherein the generation unit does not generate the conversion condition at the predetermined timing if a difference between the temperature detected by the detection unit at the predetermined timing and the temperature detected by the detection unit when the conversion condition was generated is in a predetermined range.

6. The image forming apparatus according to claim 1 , wherein the predetermined timing is a timing at which the image forming apparatus is powered on.

7. The image forming apparatus according to claim 1 , wherein the predetermined timing is a timing at which the image forming apparatus returns from a power saving mode.

8. The image forming apparatus according to claim 1 , wherein the conversion unit converts the output value output by the output unit when the light that is reflected from the measurement image is received based on a value obtained from the temperature of the output unit detected by the detection unit when the light reflected from the measurement image is received by the output unit and the conversion condition.

Assignees

• Canon Kk

Inventors

• Sekiya Takeshi

Classifications

• H04N1/02815

  Means for illuminating the original, not specific to a particular type of pick-up head · CPC title

• H04N1/2346 Primary

  according to a detected condition or state of the reproducing device, e.g. temperature or ink quantity · CPC title

• H04N1/00814

  according to a detected condition or state of the reading apparatus, e.g. temperature · CPC title

• G03G15/5045

  Detecting the temperature · CPC title

• G03G15/5041

  Detecting a toner image, e.g. density, toner coverage, using a test patch (G03G15/553 takes precedence) · CPC title