Facsimile and static presentation processing – Facsimile – Picture signal generator
Reexamination Certificate
1998-03-02
2001-02-06
Grant, II, Jerome (Department: 2724)
Facsimile and static presentation processing
Facsimile
Picture signal generator
Reexamination Certificate
active
06185011
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an image scanner, and more particularly, to a flatbed scanner with top and bottom light sources and a moveable light shield for scanning transparent and opaque documents.
2. Description of the Prior Art
Please refer to FIG.
1
.
FIG. 1
is a perspective view of a prior art scanner
10
. The scanner
10
comprises a housing
12
with a transparent platform
14
on its top end for placing a document to be scanned, and a scanning module (not shown) movably installed under the transparent platform
14
for scanning the document placed on the transparent platform
14
. The scanning module usually comprises a light source for emitting light upward and an image converter such as a CCD (charge coupled device) for converting a document image reflected from the document into a digital image. Since the light source is installed under the transparent platform
14
, the scanner
10
can only be used to scan opaque documents. If a user needs to scan a transparent document such as a photographic negative film, the user has to place a portable light panel
16
above the transparent platform
14
for emitting light downward through the transparent document and turn off the light source under the transparent platform
14
. The portable light panel
16
requires an external power adapter which should be plugged into a power socket before using. Using such a portable light panel
16
is very inconvenient.
Except for the portable light panel
16
, many scanner manufacturers provide a removable top cover equipped with a light panel for scanning transparent documents. When scanning a transparent document, a user has to remove the original top cover from a scanner, and install the top cover with the light panel. Because the top cover with the light panel is quite heavy and comprises an electric plug, the replacement of the top cover is also very inconvenient. Besides, if a user frequently needs to scan both transparent and opaque documents, the two top covers of the scanner have to be swapped quite frequently and this is very bothering.
SUMMARY OF THE INVENTION
It is therefore a primary objective of the present invention to provide a scanner which avoids replacing the top cover of the scanner to solve the above mentioned problem.
Briefly, in a preferred embodiment, the present invention provides a scanner comprising:
a housing having a transparent platform for placing a document;
a scanning module slidably installed inside the housing for scanning the document placed on the transparent platform, the scanning module comprising a bottom light source for emitting light upward toward the document and an image converter for converting an image of the document into a digital image;
a top cover movably installed on the housing;
a top light source installed under the top cover for emitting light to the document when the top cover is placed on the transparent platform;
a light shield movably installed under the top cover for shielding the top light source;
a sensor installed under the top cover for detecting whether the top light source is covered by the light shield; and a control circuit for switching on and off the top light source and the bottom light source in response to the sensor;
wherein when the top light source is covered by the light shield, the document image received by the image converter is generated by the light emitted from the bottom light source, and when the top light source is not covered by the light shield, the bottom light source will be turned off and the document image received by the image converter is generated by the light emitted from the top light source.
It is an advantage of the present invention that the scanner comprises top and bottom light sources and a moveable light shield so that when scanning a transparent document, a user only has to remove the light shield instead of the top cover. And when scanning an opaque document, only the light shield needs to be mounted on top of the top light source.
These and other objects and the advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
REFERENCES:
patent: 4540269 (1985-09-01), Thorne
patent: 4879604 (1989-11-01), Koshiyouji
patent: 4893196 (1990-01-01), Koshiyouji
patent: 4989099 (1991-01-01), Koshiyouji et al.
patent: 5038227 (1991-08-01), Koshiyouji et al
patent: 5392100 (1995-02-01), Yoshida
patent: 5606450 (1997-02-01), Chen
patent: 5703674 (1997-12-01), Nishio
patent: 5780829 (1998-07-01), Tsai et al.
patent: 5814809 (1998-09-01), Hein
patent: 5898508 (1999-04-01), Bekanich
patent: 310912 (1997-07-01), None
patent: 313936 (1997-08-01), None
Acer Peripherals Inc.
Grant II Jerome
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