Facsimile and static presentation processing – Facsimile – Picture signal generator
Reexamination Certificate
2000-07-26
2004-09-14
Coles, Edward (Department: 2622)
Facsimile and static presentation processing
Facsimile
Picture signal generator
C358S461000, C358S406000, C250S208100, C348S096000, C348S097000, C348S098000
Reexamination Certificate
active
06791721
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The following relates to an image reading device that precisely reads an original's image data with light passed through the original, and an image reading device that more precisely reads the image data by using invisible light.
2. Description of the Related Art
In recent years, technology has become known wherein frame images recorded on the originals of photographic films and the like are photoelectrically read by reading sensors such as CCDs and the like. Image processing such as enlargement, reduction, various kinds of correction and the like is applied to digital image data obtained by this reading, and images are formed on recording materials by laser light that is modulated on the basis of the processed digital image data.
In technology for digitally reading frame images with these reading sensors such as CCDs and the like, in order to achieve high precision image reading, a frame image is preparatorily read (so-called prescanning). Reading conditions (e.g., the amount of light to shine on the frame image and the charge accumulation time and the like of a CCD) are decided according to density and the like of the frame image, and the frame image is read again under the thus decided reading conditions (so-called fine-scanning).
As a light source for the aforementioned image reading, conventionally, a halogen lamp was used as a general exposure light and the like. Infrared light was removed at a filter and light was sensed as each of three primary colors (R, G, B). Original image reading was performed with respective filters attached at CCDs. At this time, to reduce the effect on image reading of dirt and damage applied to the original, the original was illuminated with diffused light from the light source.
Further, in order to perform image reading at a higher image quality, image reading devices were proposed wherein the original was illuminated with infrared light, and a CCD or the like read the transmitted light. Thus, inappropriate pixels caused by dirt or damage applied to the original were detected, and image-reading data detected for the three primary colors was corrected.
In the image reading devices described above, by convention, halogen lamps and the like were used as light sources. Halogen lamps had the disadvantages of generating large amounts of heat and occupying large spaces. They also required infrared-cut filters, light modulation filters and the like. Thus, they also had the disadvantage of increasing the number of components
SUMMARY OF THE INVENTION
In order to overcome the aforementioned disadvantages, an object of the present invention is to provide an image reading device that can be made smaller and that can read images at high image quality.
A first aspect of the present invention is an image reading device which reads an image recorded at an original, using visible light for reading the image and invisible light for detecting inappropriate pixels, and corrects inappropriate pixels of image data, including: a light source formed by light emitting diodes which emit visible light for reading the image and invisible light for detecting inappropriate pixels; an area sensor which reads the image by receiving light that has been one of transmitted and reflected by the image; and an image processing section which detects inappropriate pixels on the basis of invisible light image data, which has been read by invisible light at the area sensor, and corrects the inappropriate pixels at visible light image data, which has been read by means of visible light.
Operation of the first aspect of the present invention is explained below.
Visible light for image reading illuminates the original from the light source, visible light that is one of transmitted and reflected by the original is incident at the area sensor, and the visible light image data is read. Then, invisible light for inappropriate pixel detection illuminates the original from the light source, invisible light that is one of transmitted and reflected by the original is incident at the area sensor, and the invisible light image data is read.
Output of a wavelength in the invisible light region is not altered by image information at the original, but is altered by scattering if there is a scratch or the like at the original. On the other hand, a wavelength in the visible light region can reliably read the image at the original but, if there is a scratch or the like at the original, a scattered element is included in the image data that is read, and cannot be identified.
Accordingly, at the image processing section, inappropriate pixels of the image are detected from output alterations of the invisible image data. Inappropriate pixels of the visible image data corresponding to the same image are corrected by a method such as interpolation or the like. Hence, by illuminating the original with invisible light for detecting inappropriate pixels (in addition to the visible light for image reading), inappropriate pixels are accurately detected. Then, by correcting the visible light image data for the inappropriate pixels, high quality image reading can be carried out.
Moreover, because an area sensor is used for image reading, processing can be performed quickly.
Furthermore, because the light source is formed of light emitting diodes, it is smaller than a halogen lamp or the like. Moreover, filters and the like that transmit only one of visible light and invisible light are not needed. Thus, the number of components is decreased and costs are reduced. Moreover, the light emitting diodes emit little heat. Thus, image reading is not affected by heat from the light source.
A second aspect of the present invention is an image reading device according to the first aspect wherein the light source is formed by light emitting diode elements that emit visible light and which are disposed in array form, and light emitting diode elements that emit invisible light and which are disposed in array form.
Operation of the second aspect of the present invention is explained below.
The light emitting diode elements that emit visible light and the light emitting diode elements that emit invisible light are disposed in an array. Thus, a frame image is illuminated with different types of light. Thus, image reading and inappropriate pixel detection can be performed.
A third aspect of the present invention is an image reading device according to the second aspect wherein the light source is formed by light emitting diode elements of each of at least four wavelengths, including at least three visible light region wavelengths and one invisible light region wavelength, the light emitting diode elements of each wavelength being arranged in a pattern which is planar and which is the same as patterns of the light emitting diode elements of other wavelengths.
Operation of the third aspect of the present invention is explained below.
The three wavelengths in the visible light region may be, for example, three primary colors for reading the image at the original as a full-color image. The wavelength in the invisible light region is one of infrared light and ultraviolet light. Light emitting diodes that emit light of each of these wavelengths are disposed in planar patterns that are respectively the same as each other. Thus, unevenness is suppressed in the same way for each illumination.
A fourth aspect of the present invention is an image reading device according to the second aspect wherein the light source is formed by a plurality of types of light emitting diode elements disposed in rows and columns, which types of light emitting diode element respectively emit at different wavelengths, and the types of light emitting diode element are disposed alternately in at least one direction of a direction of rows and a direction of columns, and a ratio of a spacing between adjacent light emitting diode elements in the one direction to a spacing between adjacent light emitting diode elements in another direction is 1:(number of types of light emitting diode element).
Operation of the
Konogaya Tatsuya
Nakamura Yoichi
Coles Edward
Safaipour Houshang
LandOfFree
Image reading device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image reading device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image reading device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3235871