Photocopying – Projection printing and copying cameras – Multicolor picture
Reexamination Certificate
2003-03-06
2004-10-26
Mathews, Alan (Department: 2851)
Photocopying
Projection printing and copying cameras
Multicolor picture
C355S032000
Reexamination Certificate
active
06809795
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a device for exposing a transparent photographic original so as to project a photographic image onto a light sensitive medium or onto a recording device which converts the image into electrical signals.
Such an exposure device is known, for example, from the European Patent no. EP 0 691 568. This patent describes a matrix composed of red, green, and blue LED elements that is used to expose photographic film to project the image onto photographic paper or onto a plane-surface sensor. As is usual with conventional light sources that expose and project transparent originals, the light of an LED matrix is scattered by a scatter plate in various directions. The scatter plate causes the light to be softer, so that scratches or other defects present in the photographic original are not reproduced, or are reproduced at a reduced level.
A disadvantage of such a scatter plate, positioned after the exposure device, is that it scatters a large portion of the light emitted from the LED away from the image, thus enormously reducing the efficiency of the light source, so that the exposure time for the projection is greatly increased. that the exposure time for the projection is greatly increased.
The German Patent Application No. DE 100 41 750 (not yet published) also describes an exposure device in which images to be scanned are illuminated using LED matrices. Each LED matrix includes LED's of different colors, and the light from several matrices is combined via a beam splitter into an illumination beam path to create the image of the photographic original.
This scanner contains no scatter medium to convert the light into soft light, so that defects present in the photographic original are reproduced without limitation in the recorded image data. Therefore, the patent document claims a correction process to correct these reproduced defects. Such defect-correction processes are very computer-time intensive, particularly if many defects are present, so that rapid processing of the recorded image signals is not possible using a defect-correcting scanner. photographing, processing, or image reproduction process are undesirable.
SUMMARY OF THE INVENTION
A principal objective of this invention is therefore to configure a scanner or printer in such a manner that the processing of the images to be reproduced may occur as quickly as possible without detraction from the image quality, particularly detraction caused by the reproduction of defects. This should be realizable with relatively low cost.
This objective, as well as other objectives which will become apparent from the discussions that follow, are achieved, in accordance with the present invention, by providing an exposure device which comprises:
(a) a primary light source with a number of elements emitting light of different bands of the spectrum, the light from the primary light source traveling to the photographic original along a first optical path, and striking the photographic original at a first incident angle; and
(b) at least one additional light source whose light travels to the photographic original along at least one additional optical path, wherein the light traveling along the additional optical path strikes the photographic original at a different incident angle from the first incident angle of the first optical path.
According to the invention, a transparent photographic original is illuminated from several directions for the purpose of projection whereby the light strikes the image along differing optical paths. Each point of the photographic original is struck by light arriving at different incident angles. The light arriving at different incident angles can be combined onto the photographic original, but it is more advantageous for quick processing for the photographic original to be illuminated simultaneously from different directions.
The light emitted from the primary light source serves to project the image content of the photographic original onto light-sensitive material or an electronic receptor device. For the projection of transparent color photographic originals, light emitters emitting light in different bands of the spectrum are provided. The light emitted from them strikes either directly along the first optical path onto the photographic original, or is directed onto the photographic original by means of illumination optics consisting of additional optical elements, such as condenser lenses or mirrors.
Based on the invention, other light sources are provided, in addition to this primary light source, that serve to illuminate the photographic original. The additional light sources may be actual light sources, or actual light-emitting sources, or the additional light sources may be virtual light sources. Virtual light sources may include mirrors or beam splitters that reflect the light of an actual light source. The light from additional actual and/or virtual light sources strikes at an incident angle differing from that of the primary light source onto the photographic original. It is particularly advantageous if several additional actual and/or virtual light sources are provided whose light strikes the photographic original at several different incident angles.
The light from the primary light source projects the image information located on the photographic original onto light-sensitive material or onto a recording device. If, however, defects such as scratches or dust are present on the photographic original, the light from this light source is diffracted, scattered, or reflected. The diverted light no longer strikes the entry pupil of the projecting optics, and cannot reach the light-sensitive material or recording device. Thus, the light from the primary light source which strikes the defects in the photographic original is not projected, or is only partially projected, onto the light-sensitive material or recording device, and the image information is only incompletely reproduced. Areas with dark defects or incomplete image information corresponding to the defects are the result in the projected image. strikes the defects in the photographic original is not projected, or is only partially projected, onto the light-sensitive material or recording device, and the image information is only incompletely reproduced. Areas with dark defects or incomplete image information corresponding to the defects are the result in the projected image.
In contrast, the light from additional actual and/or virtual light sources strikes the photographic original at an incident angle different from that of the primary light source, and, after straight-line penetration of the photographic original, does not strike the entry pupil of the projecting optics. No image information from the additional actual and/or virtual light sources is projected onto the light-sensitive material or recording device unless this light is deflected in some manner. This is exactly what happens at the sites of defects. At the defective sites of the photographic original at which the light from the primary light source is deflected away from the entry pupil, the light striking the entry pupil of the projecting optics at a different incident angle is split, scattered, or reflected. Thus, the light from an additional actual and/or virtual light source that illuminated the photographic original at suitable incident angles passes through the recording optics and thus onto the light-sensitive material or correspondingly onto the recording device, thus transferring the image information present at the defect site. The image information from the primary light source missing in the reproduction is replaced by image information projected from the additional actual and/or virtual light sources. Thus, defective sites in the photographic original may be so illuminated that they are not visible in the recording, or at least have reduced effect. Since defects occur in different forms and orientations, various incident angles are required to reduce their effects by means of light entering the entry pupil
Agfa-Gevaert Aktiengesellschaft
Mathews Alan
Milde & Hoffberg LLP
LandOfFree
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