Facsimile and static presentation processing – Facsimile – Picture signal generator
Reexamination Certificate
1999-07-19
2004-11-09
Williams, Kimberly (Department: 2624)
Facsimile and static presentation processing
Facsimile
Picture signal generator
C358S496000, C358S497000, C358S453000, C382S169000, C348S345000
Reexamination Certificate
active
06816287
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image reading apparatus and a focusing control method, and particularly to an image reading apparatus for reading images of an original to be read, such as a photographic film, on which images are recorded, and to a focusing control method applied to the image reading apparatus.
2. Description of the Related Art
There has conventionally been known an image processing system in which film images recorded on a photographic film are read by an image reading apparatus including image-formation means, an image sensor, and the like, and image processing such as various corrections is effected for image data obtained by the aforementioned reading, and thereafter, an image is recorded on a recording material or displayed on a display. The photographic film as mentioned herein is a film in which negative or positive images are made visible by development processing after the photographing of a subject thereon.
Some image reading apparatuses used by this type of image processing system allow reading of a so-called slide in which a photographic film is held on a film mount provided for each kind of photographic film. In such image reading apparatuses, in order to obtain image data of high quality, automatic focusing control is performed for a film image of a slide to be read so that a position at which an image is formed by image-formation means and a position at which light is received by an image sensor coincide with each other.
However, a photographic film is generally apt to be warped, and therefore, there are many cases in which a photographic film is warped even in a state of being held on a film mount. When automatic focusing control is performed for such a warped photographic film, although an optimal automatic focused state can be set for a specified position of a film image, focusing cannot be made at other positions.
A technique which can be applied to solve the above-described problem is disclosed in Japanese Patent Application Laid-Open (JP-A) No. 4-198929: in an image reading apparatus, comprising a line CCD as an image sensor, which repeats reading image corresponding to one line along a main scan direction (that is, a direction in which pixels of the line CCD are arranged) of film image, and synchronously with the reading of image moving a photographic film in a sub-scan direction by a distance corresponding to one line, to thereby allow reading of one image, prior to reading of film image, focusing positions at a plurality of positions located in the sub-scan direction of the film image are detected, and thereafter, based on the focusing positions, focusing positions between the plurality of positions are each calculated by approximation or interpolation, and when reading of film images is performed, each time the film images are moved in the sub-scan direction, focal adjustment in which image-formation means and the image sensor are moved to obtain the previously calculated focusing positions at the plurality of positions on the film image in the sub-scan direction is repeatedly performed, to thereby maintain constantly a focused state of the photographic film with respect to the sub-scan direction.
However, in the technique disclosed in JP-A No. 4-198929, the focused state is set each time the photographic film is moved in the sub-scan direction. Accordingly, there are drawbacks in that the time required for reading an image becomes longer, and although an effect is obtained for warping caused in the sub-scan direction of the photographic film, an effect is not obtained for warping caused in the main scan direction thereof.
SUMMARY OF THE INVENTION
The present invention has been devised in order to settle the above-described drawbacks and an object thereof is to provide an image reading apparatus which allows reading of image in a short time and setting of a focused state which is effective for warping caused in a main scan direction of an original to be read.
In order to achieve the above-described object, in accordance with a first aspect of the present invention, there is provided an image reading apparatus comprising:
a light source which illuminates an original to be read, on which an image is recorded;
image-formation means which allows one of light transmitted through the original to be read or light reflected by the original to be read, to form an image;
an image sensor which reads the image recorded on the original to be read and outputs read image as image data;
moving means for moving at least one of at least a portion of said image-formation means, said image sensor, and the original to be read in a direction along an optical axis of said image-formation means; and
control means which, based on a plurality of focusing positions obtained by controlling said moving means so that focusing control which allows a position where an image is formed by said image-formation means and a position of said image sensor to coincide with each other is effected for a plurality of regions of the image, obtains a final focusing position, and which controls said moving means so that at least one of at least a portion of said image-formation means, said image sensor, and the original to be read moves to a position based on the final focusing position.
In accordance with the image reading apparatus of the first aspect of the present invention, the original to be read on which the image is recorded is illuminated by the light source, light transmitted through the original to be read or light reflected by the original to be read is allowed to form an image by the (optical) image-formation means, and the image recorded on the original to be read is read by the image sensor in a state of being separated into a plurality of pixels and further outputted as image data. The aforementioned original to be read includes a transparent original such as a photographic film, and a reflection original such as a photographic print. Further, the image sensor includes a line CCD, an area CCD, and a photoelectric element other than CCD.
Further, the image reading apparatus of the first aspect includes the moving means for moving at least one of at least a portion of the image-formation means, the image sensor, and the original to be read in the direction along the optical axis of the image-formation means. Based on the plurality of focusing positions obtained by controlling the moving means so that automatic focusing control in which the position where an image is formed by the image-formation means and the position of the image sensor coincides with each other is performed for the plurality of regions of the image, the final focusing position is obtained by the control means. The moving means is controlled by the control means so that at least one of at least a portion of the image-formation means, the image sensor, and the original to be read moves to the position based on the final focusing position.
As the aforementioned image-formation means, a lens or a lens group can be used. Alternatively, a zoom lens whose magnification can be varied by moving a part of lenses may also be used. When a lens or a lens group is used, the entire image-formation means is moved, and when a zoom lens is used, a portion of the image-formation means is moved.
As described above, according to the image reading apparatus of the first aspect, the final focusing position is obtained based on the plurality of focusing positions for the plurality of regions of the image recorded on the original to be read, and at least one of at least a portion of the image-formation means, the image sensor, and the original to be read is located at the position based on the final focusing position. Accordingly, setting of a focused state suitable for each of the plurality of regions in the image becomes possible. Even when warping is caused in the original to be read, a focused state which is effective for warping, in the main scan direction, of the original to be read can be set with the aforementioned plurality of regions being located along th
Fuji Photo Film Co. , Ltd.
Sughrue & Mion, PLLC
Williams Kimberly
Worku Negussie
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