Photocopying – Projection printing and copying cameras – Multicolor picture
Reexamination Certificate
2003-10-29
2004-11-02
Nguyen, Henry Hung (Department: 2851)
Photocopying
Projection printing and copying cameras
Multicolor picture
C355S027000, C347S251000
Reexamination Certificate
active
06812996
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an image processing apparatus, an image processing method and a program, and particularly to an image processing apparatus, an image processing method and a program that provide appropriate density in a finished film when an image is formed thereon.
PRIOR ART
In the prior art laser imager (image processing apparatus) for medical treatment, a diagnostic image is represented in density gradation. This has created a strong demand for a basic function of outputting always stable density, and various measures have been taken to ensure stable density.
The laser imager for medical treatment has a so-called calibration function of controlling the image formation portion to ensure that the digital or video signal sent from each diagnostic apparatus or imaging apparatus has a constant density on a film.
Constant density is ensured immediately after calibration has been carried out, but density is subjected to changes for various reasons with the lapse of time after calibration. The heat development process is known to be easily changed.
For example;
(1) Change in exposure system due to temperature rise in an apparatus;
(2) Change in characteristics of heat development process such as temperature rise in heat development cooling/transfer section caused by successive film processing;
(3) Change in sensitivity characteristics of the film stored in an apparatus;
(4) Change in the heat development drum characteristics due to deposition of fatty acid caused by successive film processing;
(5) Use of film different in heat development characteristics.
Sometimes a so-called density patch method is used. In this method, the density of a finished film having been exposed and developed is measured in order to compensate for these changes. Then compensation is applied to the next print. One of the known techniques according to this density patch method is the laser recoding apparatus (image processing apparatus) where the density of the film having been heat developed is measured, and the result of measurement is fed back to the intensity of laser beam. (This is disclosed in the Official Gazette of Tokkai 249138/1987)
In this density patch method, a rectangular area of about 5×10 mm at a predetermined position of a film is exposed at a predetermined light intensity, and the developed density of this area is measured. Based on the difference from the density that should be obtained (hereinafter referred to as “density for comparison”), the exposure amount and/or heat development conditions are changed to ensure the optimum density for the subsequent prints.
Accordingly, if an incorrect value is used for this density for comparison, a compensation system will determine that image density is inappropriate even if a process system reproduces an appropriate image (density). This will result in excessive or insufficient density.
The exposure and heat development systems contain causes for variation for each apparatus, and it is not preferred to use a constant value for the density for comparison.
PROBLEM TO BE SOLVED BY THE INVENTION—1
The first problem of the present invention is how to provide a density adjustment method that can keep the image density of the same diagnostic image signals within the scope of almost the same density, even if fluctuation has occurred to the characteristics of the exposure and development systems or a difference has occurred to the film characteristics in formation of a diagnostic image.
PROBLEM TO BE SOLVED BY THE INVENTION—2
The present inventors have been led to the present invention by finding out that the problem is caused by the following reasons: (1) The patch portion for measuring the finished density for obtaining the difference from the density for comparison is formed at the tip of a film so that a whole image will not be adversely affected; (2) the posture of the film separated from a heating drum and moving toward a cooling/transfer section is not constant for each machine, and fluctuation is also caused by the change in the drum heating characteristics (development characteristics) resulting from the use of a drum (this phenomenon is conspicuous due to a soiled surface especially in the case of a drum with silicon layer provided on the surface); and (3) the sensitivity on the tip of the film and that on the other portion may be different in the case of films A and B of different types, as shown in FIG.
8
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Thus, the second problem of the present invention is how to provide an image processing apparatus, an image processing method and a program wherein, even if there is any fluctuation in an image processing apparatus or films of different types (film characteristics) are used, the density value for comparison is automatically corrected using the measured density value of the patch portion immediately after calibration, whereby the default value is automatically corrected and the finished film is adjusted to have an appropriate density.
PROBLEM TO BE SOLVED BY THE INVENTION—3
In the aforementioned compensation system, comparatively stable image density is obtained if power is turned on at all times. However, if power is turned off and the operation is resumed after that, an appropriate image has not been obtained in some cases. For example, assume that the system is used for medical diagnosis, and a medical diagnostic image has to be created when the medical treatment facility is closed. Also assume that creation of a diagnostic print is completed on Friday. Based on the final print on this date, the compensation amount for the next print is stored, and printing is carried out based on the compensation amount. Diagnostic printing must be restarted on Monday of the following week. In such cases, stable density has not been obtained so far, according to the prior art. To solve this problem, the apparatus has been kept turned on even on Saturday and Sunday when the office is closed. This prior art method, however, is not recommended from the viewpoint of energy saving.
When power cannot be kept turned on by all means for the reason of security management, the only way is to restart calibration. This has resulted in excessive film consumption, according to the prior art.
The present inventors have been led to the present invention by finding out that the aforementioned problem is caused by the fact that the characteristics of the process system such as an exposure system for formation of a latent image or a heat development system for visualization of a latent image are changed in response to the turning on/off of power.
The third problem of the present invention is how to provide an image processing apparatus, an image processing method and a program characterized in that, even if power is turned off freely, the image of appropriate density can be outputted, without the need of unwanted consumption of films through calibration at every turning on of power, whereby energy is saved and a film is processed to have an appropriate density without wasting a film.
Other problems of the present invention will be apparent from the following description:
SUMMARY OF THE INVENTION
To achieve the aforementioned objects, a density adjustment method according to the present invention comprises:
an exposure step of forming an image by exposure of a film, based on the test exposure data or diagnostic image signal;
a step of developing the aforementioned latent image exposed and formed;
a step of measuring the density of the aforementioned developed image;
a step of creating a lookup table for relating the image signal and amount of exposure so as to reproduce the density specified by the diagnostic image signal, based on the aforementioned test exposure data and the measured density of the image formed on the film by the test exposure data; and
a step of correcting at least one of the exposure condition in the aforementioned exposure step and development condition in the aforementioned development step to ensure that the next film will have the optimized density, based on the difference between the measured dens
Horiuchi Makoto
Ono Youichi
Taguchi Akira
Umeki Mamoru
Frishauf Holtz Goodman & Chick P.C.
Konica Minolta Holdings Inc.
Nguyen Henry Hung
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