Facsimile and static presentation processing – Facsimile – Picture signal generator
Reexamination Certificate
1999-07-01
2003-04-22
Coles, Edward (Department: 2722)
Facsimile and static presentation processing
Facsimile
Picture signal generator
C358S487000, C358S475000, C358S474000, C358S482000, C358S471000, C358S483000
Reexamination Certificate
active
06552828
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to the field of document scanner computer peripherals. In particular, the present invention is drawn to precision deep input guide clips that guide the document over the image sensor at an optimal angle and at an optimal pressure, and to document scanners using the same.
2. Description of the Related Art
Document scanners are computer peripherals that allow users to scan documents into their computers for later storage, retrieval and/or manipulation. Although document scanners are extremely useful peripherals, they have not yet attained the ubiquity of other common peripherals, such as CD-ROM or DVD drives, printers, modems or multimedia sound cards, for example. This state of affairs persists despite the fact that prices for document scanners for personal computers are low and continue to decline rapidly. It does not appear, therefore, that price constitutes a significant barrier to entry for consumers seeking to upgrade the functionality of their personal computers and for manufacturers seeking to integrate scanners into their own products. Instead, it is believed that document scanners have not, to date, realized their anticipated success due to a combination of shortcomings including lack of integration, poor reliability, difficulty of use and slow speed.
Several types of scanners exist, each type being specifically designed for a particular purpose: monochrome, color, sheet-fed, flatbed, handheld, photo-print, photo-slide, SCSI host interface, printer port host interface, IEEE1284 parallel port host interface, serial port host interface, USB host interface, IEEE1394 FireWire host interface, etc. Development costs and time to market are therefore significant. Only scanner manufacturers that are fully committed to document scanner products can afford to be involved in document scanner developments. Manufacturers that wish to incorporate document scanner functions into other types of equipment (multifunction terminals, consumer appliances, gaming devices for example) in order to differentiate their products from those of the competition have experienced difficulties in meeting their goal.
FIG. 1
shows a typical arrangement for a sheet-fed document scanner. In
FIG. 1
, a document
1
is displaced by a rotating roller paper feeding mechanism
3
driven by a motor
4
over a fixed image sensor
2
that senses reflected light from the document
1
. Alternatively, the paper feeding mechanism may be a belt, a plurality of rollers or a combination of one or more rollers and belts. Illumination is provided from the image sensor
2
. The image sensor
2
, together with its associated electronics (not shown), records a line of information at a time. When the document
1
is driven by the motor
4
and the roller
3
, the image sensor
2
records the entire document area swept. The scanner control electronics and the communication link with the host computer are not shown, for clarity.
FIG. 2
shows a typical arrangement for a duplex document scanner. In
FIG. 2
, a document
1
is displaced by two rotating rollers
3
and
6
driven by a motor
4
over two fixed image sensors
2
and
5
that sense reflected light from each side of the document. Alternatively, the paper feeding mechanism may be a plurality of belts (one shown at reference numeral
7
in FIG.
2
), or a plurality of rollers and belts. Illumination is provided from each image sensor
2
,
5
. The image sensors
2
,
5
, together with their associated electronics (not shown), record a line of information for each side of the document
1
. When the document
1
is driven by the motor
4
and the rollers
3
,
6
, the image sensors
2
,
5
, together with their associated electronics, record the entire area swept of the document
1
on both sides thereof. The scanner control electronics and the communication link with the host computer are not shown in FIG.
2
.
The image sensors used in sheet-fed and duplex scanners, for example, may be charge-coupled devices (CCD), monochrome or color sensors having a width of approximately 40 to 60 mm fitted with a suitable optical apparatus to reduce the image of the document and an illumination source or monochrome or color contact image sensors (CIS). These image sensors are usually available in B6, A4, A3 sizes or approximately 100 mm to 300 mm. The image sensors produce an analog signal that is commonly called a video signal. Illumination for sheet-fed and other types of scanners (e.g., flatbed scanners, slides scanners) and duplex scanners may be produced using light emitting diodes (LED), cold cathode fluorescent light (CCFL) tubes, electro-luminescent screens or filament lamps, for example. Color dropout (the elimination of a color) may be produced by using color filters that block a selected wavelength or by selecting light sources that generate the selected wavelength.
In both of the scanners shown in
FIGS. 1 and 2
, however, the document
1
is dragged across the surface of the glass covering the image sensors
2
,
5
. The document
1
, however, may be soiled, and have abrasive particles clinging thereto. The document
1
moreover, even though apparently unsoiled, may itself contain abrasive impurities therein. In addition, the ink used on the document
1
may not be fully dry and may leave an oily residue on the image sensor transparent (typically glass) surface. These abrasive particles, impurities and residues may, with repeated usage, scratch and obscure the surface of the glass covering the image sensors
2
,
5
, thereby degrading the quality of the resulting scanned image. This scratching may be further exacerbated by the roller
3
,
6
pressing the document
1
against the glass of the image sensors
2
,
5
with too great a pressure. The quality of the scanned images may also suffer from the effects of parasitic ambient light impinging upon the image sensors
2
,
5
. Such ambient light may reach the sensors
2
,
5
as the sensors
2
,
5
are not protected therefrom, particularly when the leading edge of the document
1
is dragged across the sensors
2
,
5
.
What are needed, therefore, are improved scanners that do not suffer from the forementioned disadvantages. Specifically, what are needed are document scanners with improved resistance to such soiling, scratching or obscuring of the image sensor glass. What are also needed are document scanners and associated document feeding mechanism that eliminate or reduce the amount of parasitic ambient light that is allowed to reach the scanner sensors.
SUMMARY OF THE INVENTION
An object of the present invention, therefore, is to provide document scanners that are resistant to such soiling, scratching or obscuring of the sensor glass or other corresponding transparent surface. It is another object of the present invention to provide a document scanner having an improved document feeding mechanism that introduces the document into the scanner at an optimal angle and at an optimal pressure to eliminate or reduce the glass scratching problems often associated with conventional document scanners, even when subjected to heavy usage patterns. Such a document scanner should also protect the image sensors from parasitic ambient light, thereby resulting in an improved scanned image quality.
In accordance with the above-described objects and those that will be mentioned and will become apparent below, a document scanner, according to an embodiment of the present invention, comprises:
an image sensor, the image sensor including a transparent surface over an optical focus line;
a feed roller motor;
a rotatable feed roller coupled to the feed roller motor, the feed roller being adapted to contact said transparent surface along a contact line that is offset from said optical focus line; and
a generally U-shaped deep input guide clip, the deep input guide clip including a plurality of retaining bends to clip onto the image sensor and including a document facing surface defining an opening aligned with the transparent surface, the retaining bends
Coles Edward
Cyberscan Technology, Inc.
Safaipour Houshang
Young Law Firm P.C.
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