Facsimile and static presentation processing – Facsimile – Picture signal generator
Reexamination Certificate
2001-10-23
2004-07-13
Lee, Cheukfan (Department: 2622)
Facsimile and static presentation processing
Facsimile
Picture signal generator
C358S497000
Reexamination Certificate
active
06762861
ABSTRACT:
BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to a scanner, and more particularly, to a scanner that has a movable mirror set inside its scanning module for increasing the resolution of scanned images.
2. Description of the Prior Art
FIG. 1
is a perspective view of a prior art scanner
10
. The scanner
10
comprises a housing
12
, a transparent platform
14
onto which a document
18
is placed, and a scanning module
16
for scanning the document
18
. The operator of the scanner
10
lays the document
18
face down on the transparent platform
14
. The scanning module
16
moves along a track inside the housing
12
and reads the document
18
through the transparent platform
14
.
FIG. 2
is a cross-sectional view of the scanning module
16
cut along line
2
—
2
. The scanning module
16
comprises a light source
22
, a fixed mirror set
23
, a lens
26
, and a charge coupled device (CCD)
28
. As the scanning module
16
moves across the document
18
, the light source
22
illuminates the document
18
. The image of the illuminated document
18
is reflected by the mirror set
23
. The lens
26
then focuses the image of the document
18
onto the CCD
28
.
The resolution of the scanned image is determined by how many photosensitive cells are built into the CCD
28
. Resolution is measured in dpi (dots per inch) and for a scanner
10
to scan at 600 dpi, 600 photosensitive cells must be built into each inch-long strip of the CCD
28
. To increase the resolution to 1200 dpi, twice as many photosensitive cells must be used when manufacturing the CCD
28
. As the desired resolution increases, the cost of manufacturing the CCD
28
increases. It is therefore an important objective to increase the resolution of the scanned image and still keep manufacturing costs low.
SUMMARY OF INVENTION
It is the primary objective of the claimed invention to provide a scanner in which a method may be employed to increase the resolution of a scanned image without increasing the number of photosensitive cells.
According to the claimed invention, the scanner comprises a housing, a transparent platform installed on the housing for placing a document, and a scanning module installed inside the housing for scanning the document. The scanning module comprises a first mirror set fixed inside the scanning module for reflecting light transmitted from the document, a second mirror set moveably installed inside the scanning module for changing an optical path of the light transmitted from the document so as to change resolution of a scanned image, and a lens set moveably installed inside the scanning module for focusing the light transmitted from the first and second mirror sets. When the second mirror set is moved to change the resolution of the scanned image, the lens set will move correspondingly to adjust the focus of the light transmitted from the first and second mirror sets.
It is an advantage of the claimed invention that the resolution of the scanned image can be increased without increasing the number of photosensitive cells built into the CCD.
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: 5117256 (1992-05-01), Haibara
patent: 5691824 (1997-11-01), Haded et al.
patent: 5845019 (1998-12-01), Yoshizawa et al.
patent: 5883727 (1999-03-01), Tsai
patent: 5907411 (1999-05-01), Han
patent: 6124952 (2000-09-01), Shieh et al.
patent: 6603514 (2003-08-01), Tsai et al.
Hsu Winston
Lee Cheukfan
Primax Electronics Ltd.
LandOfFree
Scanner with a movable mirror set in the scanning module for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Scanner with a movable mirror set in the scanning module for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Scanner with a movable mirror set in the scanning module for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3229364