JPH11284810A - Image acquisition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent set-off of a double side original without much decreasing an effective contrast of the original by a copying machine or a scanner. SOLUTION: In the case that a reflectance of a front side of an original cover in contact with a rear side of an original is high, set-off is remarkable. On the other hand, in the case that the reflectance is too low, the set-off is sufficiently suppressed but deterioration in an effective contrast is especially remarkable in an original whose light transmissivity is comparatively high. Then the reflectance of the reflecting face is controlled less than 90%. Adjusting the reflectance to be about 60-75% satisfies especially both of two trade-off objects.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION This invention relates generally to scanners, copiers, facsimile machines, and other devices used to convert an optical image of a document into an electronic signal, and more particularly to providing an image. Regarding the reflective surface used on the back side of the document.

[0002]

BACKGROUND OF THE INVENTION Electronic document scanners, copiers, and facsimile machines convert an optical image of a document into an electrical signal suitable for storage, display, printing, or electronic transmission. Scanned documents are generally classified as either transparent or opaque. For an opaque document, light is reflected from an image on the surface of the document and impinges on a photosensitive transducer, typically a photoconductive drum or an array of photosensitive sensor elements. However, documents are rarely completely opaque. In a typical device, some light passes through the document to a secondary reflective surface, such as a lid or an automatic document feeder. Some light then reflects off this secondary reflective surface and returns through the document again. Light that has passed twice through the document may also be detected by the photosensitive transducer. If the document has images on both sides, the image on the side of the secondary reflective surface may be partially imaged on the photosensitive transducer. For example, when copying a two-sided document, an image of the back side of the document may appear partially in the resulting copy. This undesirable result is often called bleed-through.
There is a need to reduce show-through in copiers, scanners, facsimile machines, and similar devices.

FIG. 1 shows a prior art scanner cover having a reflective surface 103a on the scanner cover 103f. The reflecting surface 103a is made of a transparent polyester film 1
03b is formed by evaporating silver, chrome, or aluminum on one side. On the reflection surface 103a,
A hard plate 103d of a hard plastic material is bonded. In addition, the plate 103d is supported by a hard plastic material scanner cover 103f having reinforcing feet 103e. Alternatively, for example, a metal can be deposited on the plate 103d or the plate 103d can be made of metal.

FIG. 2 shows another prior art scanner cover and reflective surface. In the figure, a document cover 103 includes a resin cover 103f, an elastic member 103g such as a sponge, a hard plate 103d made of a plastic material that does not easily deform, and a transparent polyester material having a reflective metal surface on one side.
Including the film 103b. These are stacked in the order described above. Since the hard plate 103d is sandwiched between the reflection surface 103a and the elastic member 103g, the surface 103a can push the three-dimensional original softly without being deformed when the original is placed under the three-dimensional original. Alternatively, metal can be deposited on plate 103d or plate 103d can be made from metal.

FIG. 3 shows another prior art scanner cover and reflective surface. In the figure, the layer 103b in FIG. 1 is supported by a resin sheet 103h, which is a transparent and flexible synthetic resin. For this reason, it is strong against a possible impact or the like. In FIG. 3, the reflecting surface 103a is shown as being formed between the sheet 103b and the sheet 103h, but may be between the sheet 103b and the sheet 103d.

[0007]

SUMMARY An improved document lid and secondary reflective surface are provided that minimize show-through and other problems associated with other important image parameters such as brightness, contrast, color shift, and the like. The document lid and secondary reflective surface also allow for cost and labor savings on the lid,
And the lid can be recycled.

[0008]

DETAILED DESCRIPTION FIG. 4 illustrates a document 100 placed face down on a transparent platen 102 having a lid or automatic document feeder 104. Document 100 has an image on front 110 and back 12
It may have a second image on zero. The lid or automatic document feeder 104 forms a secondary reflective surface 114. Lamp 106 provides light beam 108. Ray 1
The majority of 08 is reflected from the front face 110 of the document 100 to produce a front reflected ray 112. A portion of the light beam 108 passes through the document 100 and
, Passing through the second image on the back side 120 of the document and back through the document 100, producing a secondary reflected ray 116. Light rays 112 and 116 are both received and converted by photosensitive transducer 118. Transducer 118 may be a photosensitive drum or an array of photosensitive elements, or may scan a single beam of light and reflect it onto a single sensor. In this figure, lenses, mirrors, and other optical components that are irrelevant to the present invention, which are originally included in the scanning apparatus, are omitted and simplified.

[0009] Secondary reflected rays 116 are particularly important when scanning or copying color images, where accurate color reproduction (as perceived by the human visual system) is required. One way to eliminate the secondary reflected rays and the resulting show-through is to make the surface 114 non-reflective (black). However, a black surface can have other undesirable effects, such as: First, consider the dynamic range (ie, contrast) of the image, which is the difference in reflectivity between the darkest part of the image (also called shadow) and the lightest part of the image (also called highlight). let's watch. Document 100 is typically paper. If light can be reflected back through bright areas of the image, the bright areas will appear whiter, increasing the effective dynamic range. As an extreme example, consider the image on thin tissue paper. Bright areas of the image appear whiter when viewed on a white background. When viewed on a black background, light areas shift toward gray, reducing the dynamic range of the image. Second, a black background can cause a color shift. Blank paper usually acts as an optical filter,
Short wavelengths are suppressed and long wavelengths are passed. That is, white paper has a higher transmission for red and green wavelengths than for blue wavelengths. Again, use the extreme example of an image on thin tissue paper. When viewed on a white background, the red and green saturations are relatively increased and appear bright.
When viewed on a black background, red and green appear less saturated. Sensoryly, red tends to be relatively dull, ie, brick-like in color. Thus, for both dynamic range and color shift reasons, reflecting surface 1
It is not desirable to make 14 completely non-reflective.

In general, reducing the secondary reflectivity to less than about 30% results in appreciable color shifts in typical color images on typical white paper and reduces dynamic range. there is a possibility. The secondary reflectivity should preferably be at least 60% in order to keep the color shift and the dynamic range in a perceptually acceptable range. At another extreme, providing greater than 90% reflectivity can result in noticeable show-through on typical two-sided paper documents. A reflectivity of less than 75% is desirable to reduce show-through. Thus, the preferred range is to set the reflectivity to 60% as an acceptable compromise.
To 75%, while significantly reducing show-through, while reducing the resulting dynamic range and perceived color shift.

Many commercial products have a reflectance between 60% and 75%.
Made from molded tan or gray plastic in the% range. Typically, copier lids and scanner lids have a separate white surface or are painted white. Based on the above considerations, it is often desirable to use the plastic color of the product without modification to eliminate extra manufacturing costs. In addition, scanners and other equipment that use arrays of charge coupled devices have a calibration strip that is often used to measure the variability of individual sensors. The primary requirement of this calibration strip is that it be uniform along the strip (and perhaps even reflectivity between the strips). Cosmetic tinting of the plastic case often allows the plastic case to be used as a sensor uniformity calibration strip. Thus, an unpainted lid can also provide a uniformity calibration. As mentioned in the description of the prior art, the lid of a plastic copier or the lid of a scanner is usually manufactured using an injection molding method, and then the foam,
A layer of adhesive, reflective film, and a transparent protective film is attached to the scanner lid adjacent to the copier surface or the subject surface.

As shown in FIG. 5, the shape of the mold is such that the copier or scanner lid 200 matches the typical shape combination of lid, foam, adhesive, reflective film, and transparent protective film. Alternatively, the plastic lid 200 of the scanner or copier can itself be used as the secondary reflective surface 202. To ensure that the secondary reflective surface 202 of the scanner or copier lid 200 is defect-free and has a suitable reflective surface, the surface area of the molding tool may need to be polished or roughened. Absent. The molding tool needs to be reshaped so that the scanner or copier lid 200 can press the document 208 to be scanned or copied against the platen glass 204 of the scanner or copier. In such cases, the typical tan, grey, putty colors of plastic used in most electronic devices, computers, copiers, scanners, printers, etc., show-through,
60% -75% has proven to be an acceptable compromise between dynamic range and perceived color
Is a suitable color to provide a reflectance in the range

If the plastic scanner or copier lid 200 is modified and used as the secondary reflective surface 202, there are significant savings in parts, materials, and labor in manufacturing the scanner or copier. This is because, in particular, conventional foam / film / adhesive reflector assemblies are generally complex to align and mount under the lid of a scanner or copier. Furthermore, the lid 200 of the scanner according to the invention is recyclable as a single plastic part. In contrast, prior art scanner lids are generally not recyclable because the foam / film / adhesive reflector assembly is typically not removable or very expensive and laborious to remove from the scanner lid. . Thus, scanner lids or copier lids with secondary reflective surfaces according to the present invention are recyclable, and prior art scanner lids or copier lids are not recyclable.

The inventor of the present application has found that a substantially white secondary reflective surface is usually best for scanning / copying a transparent film, and a substantially black secondary reflective surface is scanned / copied with an OCR (optical character reader). And a secondary reflective surface that is nearly gray, i.e., 60-75% reflectivity,
It has been found that it is best for scanning / copying color documents. Therefore, scan /
Optimally, the end user can change the color of the secondary reflective surface based on the document being copied.

FIG. 6 illustrates a scanner or copier lid 300 having a secondary reflective surface 302 on which a document 308 to be scanned or copied can be pressed against a platen glass 304 of the scanner or copier. Another example is illustrated. The reflective surface 302 is made of a plastic of any color and is provided in the scanner / copier lid 300 using sliding or mating means 310 on the scanner / copier lid 300 and sliding or snapping means 312 on the reflective surface 302. Slide or slide in or snap fit or snap into place. Slide / snap means 312 and reflective surface 3
Numeral 02 is preferably a single integral part made of plastic. According to this embodiment of the invention, the end user removes the current reflective surface 302 and replaces it with another reflective surface 302 of a different color, thereby providing a reflective surface 3.
02 color can be changed.

Scan / for any given document
It is relatively easy to fabricate the plastic reflective surface 302 of various predetermined colors in order to optimize the copy conditions, and there are no special considerations. However, at this time, it is believed that just having a reflective surface 302 in three colors (ie, black, white, and grey / tan or putty color) would meet the scan / copy requirements for most documents. . Thus, if the end user determines that a transparent document must be scanned or copied, the white reflective surface 302 need only be slid or snapped into the scanner / copier lid 300. If the end user determines that a color document needs to be scanned or copied, the grey, tan, putty reflective surface 302 can simply be slid or snapped into the scanner / copier lid 300. good. If the end user determines that the document needs to be scanned or copied by OCR, then the black reflective surface 302 need only be slid or snapped into the scanner / copier lid 300.

According to the scanner / copier according to this embodiment of the present invention, optimum scanning / copying conditions for almost all documents can be realized. The present invention reduces manufacturing costs for parts and labor. Also,
The end user can determine which reflective surface 302 is needed. The reflective surface 302 and the lid 300 of the scanner / copier are made of plastic, adhesive, foam,
Both the scanner / copier lid 300 and the reflective surface are recyclable, as they are made entirely of injection molded plastic, rather than the usual configuration of metal / plastic film and plastic film layers.

The foregoing description of the present invention has been presented for purposes of illustration and description. For example, reflective surfaces can be screwed or Velcro not simply snap-fitted or slide-fitted.
It can be attached to the lid by any available means, such as o). Nevertheless, it would be preferable for the attachment means to be easily removable and re-fittable by any end user. A key concept of the present invention is that the reflective surface can be recycled by itself or with the lid of a scanner / copier integrated therewith. The above description is not intended to be exhaustive or to limit the invention to the precise form disclosed, and other modifications and variations are possible in light of the above teaching. The choice of embodiments and the description thereof best explain the principles of the invention and its practical application, and enable those skilled in the art to make various modifications and adaptations of the invention which are appropriate to the particular intended application. Made to be best available. It is intended that the appended claims be construed to include other alternative embodiments of the invention except insofar as limited by the prior art.

Examples of the embodiments of the present invention will be listed below.

[Embodiment 1] The following (a) and (b) are provided,
Apparatus for electronically converting an image located on a first surface into an electronic signal: (a) an area adapted to receive a document (100, 208, 308);
Having a first image (110) on a second surface and a second image (120) on a second surface, wherein the first image is located on the first surface; (b) A) a reflective surface (114) adjacent to the second surface of the document: the reflective surface has a reflectance of less than 90%;
This reduces the electronic conversion of the second image (120) by the device when converting the first image (110).

[Embodiment 2] The apparatus according to embodiment 1, wherein the reflection surface has a reflectance of less than 75%.

[Embodiment 3] An embodiment 2 characterized in that the reflection surface has a reflectance of more than 60%.
An apparatus according to claim 1.

[Embodiment 4] The following (a) to (e) are provided,
An image processing device for converting an image into an electronic signal: (a) a surface (204) supporting a document (208); (b) a lid for covering a back surface of the document supported on a surface of the support surface (204) (200): the lid has a light reflecting surface (202) facing the support surface, wherein the light reflecting surface is made of the same material as the lid and is integral with the lid; A light source that illuminates the document supported on a support surface (204); (d) a photodetector that generates an electrical signal in response to light reflected by the document; (e) a light detector that is generated by the photodetector. Means for processing the electrical signal.

[Fifth Embodiment] The image processing apparatus according to the fourth embodiment, wherein the light reflecting surface has a reflectance of 60% or more and 75% or less.

[Embodiment 6] An image processing apparatus provided with the following (a) to (e) and converting an image into an electronic signal: (a) a support member having a surface (304) for supporting a document (308); (b) a lid (300) for covering the back surface of the document supported on the front surface (304) of the support member: the lid has a light reflecting surface (302) facing the support surface, and The reflective surface is made from the same material as the lid, and the original is to be processed by the image processing device by removing the light reflective surface and replacing it with another lid having a different reflectance. (C) a light source for illuminating the document supported on the support surface; and (d) responsive to light reflected by the document. Photodetector that generates an electrical signal by e) means for processing the electrical signal generated by the photodetector.

[Seventh Embodiment] The image processing apparatus according to the sixth embodiment, wherein the light reflecting surface and the lid are made of plastic.

[Eighth Embodiment] An image processing apparatus according to the seventh embodiment, wherein the light reflecting surface can be snap-fitted into the lid.

[Embodiment 9] The image according to Embodiment 7, wherein the reflecting surface (302) can be slid into the lid (300) and can be slid and removed from the lid. Processing equipment.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross section of a lid of a first scanner having a reflecting surface according to the prior art.

FIG. 2 shows a cross section of a lid of a second scanner having a reflecting surface according to the prior art.

FIG. 3 is a diagram showing a cross section of a lid of a third scanner having a reflecting surface according to the prior art.

FIG. 4 is a diagram illustrating a cross-section of an image device cover including a secondary reflecting surface according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a cross-section of an image device cover including a reflective secondary reflective surface according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating a cross section of an image device cover including a reflective secondary reflective surface according to a third embodiment of the present invention.

[Explanation of symbols]

 100: Document 102: Platen 104: Automatic Document Feeder 114: Secondary Reflection Surface 106: Lamp 108: Light Ray 112: Front Reflection Ray 116: Secondary Reflection Ray 118: Photosensitive Transducer

 ────────────────────────────────────────────────── ─── Continued on front page (72) James Jay Graham, Inventor Fort Collins, Colorado, USA South County Road 5 1609 Court 800 (72) Inventor Julie T. Dow Fort Collins, Colorado, United States Stoneway Court 4028

Claims (1)

[Claims] An apparatus for electronically converting an image located on a first surface into an electronic signal, provided with the following (a) and (b): (a) receiving a document (100, 208, 308); Area made to: The document is the first
Having a first image (110) on a second surface and a second image (120) on a second surface, wherein the first image is located on the first surface; (b) A) a reflective surface (114) adjacent to the second surface of the document: the reflective surface has a reflectance of less than 90%;
This reduces the electronic conversion of the second image (120) by the device when converting the first image (110).