Image reading apparatus

Image analysis – Image sensing – Multiple scanning

Reexamination Certificate

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Reexamination Certificate

active

06618512

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image reading apparatus, and more particularly, an image reading apparatus which reads images recorded on an image recording material such as a photographic photosensitive material.
2. Description of the Related Art
A photographic film may be scratched on an emulsion surface or a back surface (the surface opposite the emulsion surface) depending on how the film is handled. When a photographic film has a scratch on a portion that corresponds to an image recording area and an image recorded on the photographic film is output (i.e., the image is recorded on a recording material such as photographic printing paper, or displayed on a displaying means such as a display), the scratch on the photographic film is often, depending on the size, depth or type of the scratch, clearly visible on the output image as a defect portion, such as a low density streak or a white streak. Also, when a photographic film has foreign matter such as dust on the surface, the foreign matter is clearly visible on an output image as a defect portion.
A surface exposure type photographic printing apparatus, which exposes and records an image onto photographic printing paper by irradiating a photographic film with light such that light transmitted through the photographic film irradiates the photographic printing paper, includes a diffusion plate disposed between a light source and the photographic film and irradiates the photographic film with light diffused by the diffusion plate, as a countermeasure for scratches on the photographic film. However, with the above-described technique, defects in an output image (the image exposed and recorded on photographic printing paper) are only slightly reduced (the defect portions only become slightly less obtrusive).
As a technique applicable to an image reading apparatus which reads an image recorded on a photographic film by a reading sensor such as a CCD, Japanese Patent Application Laid-Open (JP-A) No. 11-75039 has disclosed a technique of reading a photographic film with at least four lights corresponding to four wavelength ranges (three wavelength ranges of visible light and one wavelength range of invisible light, for example, infrared or ultraviolet), and correcting image information obtained by visible light readings on the basis of information obtained by an invisible light reading.
Amounts of visible light transmitted through the photographic film vary with image density of an image recorded on the photographic film, and are also varied at a portion of the photographic film having a scratch or foreign matter because a portion of the visible light irradiated to the portion of the photographic film is refracted or reflected at the portion of the photographic film. On the other hand, although amounts of invisible light transmitted through the photographic film vary at the portion of the photographic film having the scratch or foreign matter, the amounts are not affected by density of the image recorded on the photographic film.
Therefore, in accordance with the technique described in JP-A No. 11-75039, by detecting scratches and foreign matter on the photographic film on the basis of variations in amounts of invisible light transmitted through the photographic film, corrections for variations in amounts of visible light transmitted through the photographic film, which variations are due to scratches and foreign matter on the photographic film, i.e., corrections for defect portions in an image (an image represented by image information obtained by visible light readings) caused by the scratches and foreign matter on the photographic film, can be made with assurance.
To read an image recorded on a photographic film with high accuracy, it is desirable to read the image preliminarily at a relatively low resolution (pre-scanning), determine reading conditions on the basis of results of pre-scanning, and then read the image finally at a relatively high resolution (fine-scanning) under the determined reading conditions. However, in the technique described in JP-A No. 11-75039, optimal timing of reading with invisible light when two readings, pre-scanning and fine-scanning, are performed is not considered.
For example, when two readings, pre-scanning and fine-scanning, are performed, reading with invisible light may be performed during both pre-scanning and fine-scanning. In such a case, by performing a reading with invisible light during pre-scanning, status of defect portions can be tested, for example, during an image test carried out on the basis of an image displayed on a display or the like and, by performing a reading with invisible light during fine-scanning, defect portions can be detected with high accuracy and highly accurate corrections can be made, because the reading is performed at a high resolution. However, a problem with reading with invisible light during both of pre-scanning and fine-scanning is that reading takes a long time.
As described above, timing of reading with invisible light greatly affects accuracy of correction for defect portions and reading speed. However, required levels of accuracy of correction for defect portions, reading speed and the like when reading an image often differ between individual cases. For example, there are cases in which high reading speed is desired but high accuracy of correction for defect portions is not required. Conversely, there are cases in which a high quality image whose defect portions are corrected with high accuracy is desired even if reading speed is slow.
SUMMARY OF THE INVENTION
The present invention is intended to solve the above-described problems, and the first object of the present invention is to provide an image reading apparatus which detects defect portions in an image and can reduce reading time.
The second object of the present invention is to provide an image reading apparatus which can perform image reading so as to satisfy various requirements.
A first aspect of the present invention, to accomplish the first object, is an image reading apparatus including a reader which reads an image recorded on an image recording material; a detector which irradiates the image recording material with first light in an invisible region and detects second light in the invisible region which is one of the first light transmitted through and reflected from an image recording area in which the image is recorded; and a controller which effects control such that a preliminary reading of the image is performed by the reader, after which detection of the second light in the invisible region is performed by the detector, after which, and a fine reading of the image is performed by the reader under reading conditions determined on the basis of information obtained by the preliminary reading.
In the first aspect of the present invention, the reader reads the image recorded on the image recording material, and the detector detects the light transmitted through or reflected from the image recording area of the image recording material in which the image is recorded (the second light). Thereby, defect portions due to scratches or foreign matter in the image recording area of the image recording material can be detected on the basis of result of detection of the second light by the detector. Further, image data for which defect portions due to scratches and foreign matter on the image recording material have been corrected can be obtained by, for example, correcting image data obtained by reading of the image by the reader on the basis of results of detection of the second light by the detector.
Further, in the first aspect of the present invention, the controller effects control of the reader and the detector so as to perform the detection of the second light by the detector after the preliminary reading by the reader is performed, and then to perform the final reading (fine reading) by the reader. That is, detection of the second light by the detector can be performed only once, thereby reducing image reading time. When dete

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