Facsimile and static presentation processing – Facsimile – Picture signal generator
Reexamination Certificate
1999-02-12
2001-01-09
Lee, Cheukfan (Department: 2722)
Facsimile and static presentation processing
Facsimile
Picture signal generator
C358S471000, C358S496000, C358S498000
Reexamination Certificate
active
06172774
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a support structure for image reader optical unit for reading the information displayed on a manuscript surface as an image, in which the optical unit is mounted on a frame provided in such a manner as to be swung open around a fulcrum shaft. The support structure according to this invention is particularly suitable for an automatic paper-feed image reader of a double-side reading type.
DESCRIPTION OF THE RELATED ART
There are two types of image input device used as a device for inputting image information to a computer and other information processing equipment: one is the fixed document type often called the flat-bed type, and the other is the stationary optical unit type called the automatic paper-feed type. In addition, a two-in-one unit combining the flat-bed type with the automatic paper-feed type is also known.
FIG. 5
shows a typical example of a conventional type of image reader having a flat-bed reader section A and an automatic paper-feed reader section B. The flat-bed reader section A comprises a document board
1
made of a transparent plate, a swingable document holder
2
placed on the document board
1
, and a moving optical unit
3
traveling over the document board
1
; a document placed on the document board
1
being read by causing the moving optical unit
3
to travel over the document board
1
.
The automatic paper-feed reader section B, on the other hand, comprises a document carrier
4
for carrying a document, a document feeder
8
having a paper-feed roller
5
and two pairs of feed rollers
6
and
7
, a stacker
9
for holding document sheets that have been read, and a stationary optical unit
11
provided at a fixed location; a document sheet held between the feed roller pairs
6
and
7
and traveling at a constant speed from the right to the left in the figure being read by the stationary optical unit
11
provided at a fixed location.
A bound document, such as a book, can be read by the flat-bed reader section A, while multiple separate sheets of document can be continuously read by the automatic paper-feed reader section B. When a document is read by the automatic paper-feed reader section B, both sides of a traveling document sheet can be read by disposing the moving optical unit
3
at a location substantially facing the stationary optical unit
11
so that both the optical units
3
and
11
can read both sides of a document sheet simultaneously.
The optical units
3
and
11
each have an image sensor
12
, an image pickup lens
12
, a reflecting mirror
14
for deviating an optical path, and a light-source lamp
15
for illuminating the document.
The automatic paper-feed reader section B comprises a lower frame
16
and a swingable upper frame
17
so that the document path can be opened in case of paper jams. The upper frame
17
is pivotally fitted to the lower frame by a fulcrum shaft
22
, so that a document path
23
is opened by lifting the upper frame
17
upward by disengaging a lock (not shown) provided on the side of the document carrier
4
.
The apparatus shown in
FIG. 5
is a bottom feed type, in which document sheets on the document carrier
4
are fed one by one from the bottom, with the paper-feed roller
5
provided below the document path
23
, rotatably supported by the lower frame
16
. A separating pad
18
for separating paper sheets is provided on the side of the upper frame
17
elastically held in contact with the outer periphery of the paper-feed roller
5
. The feed roller pairs
6
and
7
feed the document by holding a document sheet between upper rollers
6
a
and
7
a
and lower rollers
6
b
and
7
b
, both rotatably supported by the upper frame
17
and the lower frame
16
, respectively.
The paper-feed roller
5
and the feed roller pairs
6
and
7
are normally driven simultaneously by a single motor
19
. In a type where an automatically fed document sheet is read by moving a moving optical unit
3
to the position of the automatic paper-feed reader section B, as shown in
FIG. 5
, however, it is necessary to reduce the size of the apparatus by installing the motor
19
and other rotation transmission mechanisms
21
in the upper frame
17
since there is not enough space for the motor
19
and other transmission mechanisms
21
in the lower frame
16
.
In the example shown in
FIG. 5
, the upper rollers
6
a
and
7
a
of the feed roller pairs
6
and
7
serve as driving rollers, while the lower rollers
6
b
and
7
b
as driven rollers rotatably supported in a free-running state. Rotating power is transmitted to the paper-feed roller
5
via a pair of gears provided on the upper and lower frames, which are brought in mesh with each other when the upper frame
17
is closed.
Attempts to miniaturize an image reader of the aforementioned construction by installing the motor
19
and other transmission mechanisms
21
for driving the roller pairs
6
and
7
of the automatic paper-feed reader section B and the document feeder
8
would involve a problem of deterioration in the reading performance of the stationary optical unit
11
provided on the upper frame
17
caused by the vibration generated from these pieces of equipment and propagated to the upper frame
17
. The upper frame
17
, which is pivotally supported by the lower frame
16
around the fulcrum shaft
22
, has low rigidity in the support structure thereof. Any attempt to achieve a small-sized. lightweight equipment with high reading line density using the aforementioned construction would inevitably encounter the problem of aggravated reading quality of the stationary optical unit
11
due to the vibration of the upper frame
17
.
SUMMARY OF THE INVENTION
It is a technical task of this invention to obtain technical means to implement an image reader having a swingable upper frame
17
pivotally supported by a lower frame
16
by a fulcrum shaft
22
, with a motor
19
for feeding document and other vibration sources installed on the upper frame to prevent the reading quality of the optical unit installed on the upper frame from being aggravated due to the vibration of the upper frame.
To accomplish the aforementioned task, this invention provides an image reader comprising a lower frame disposed below a document path, an upper frame disposed above the document path and pivotally supported by the lower frame via a fulcrum shaft, and an optical unit disposed above the document path, with a motor for driving a document feeder and/or the rotation transmission mechanism thereof installed on the upper frame; the optical unit having a unit frame that is separate from the upper frame; the unit frame and the upper frame being pivotally supported independently in non-contact state by a common fulcrum shaft supported by the lower frame with the respective closed positions thereof being locked independently via stoppers provided on the lower frame.
In the aforementioned conventional type of image reader, the upper frame
17
is apt to vibrate partly because of the existence of gaps between the fulcrum shaft
22
and the hole on the upper frame through which the fulcrum shaft
22
is passed, and partly because of the low rigidity of portions locked by the stopper. Increasing the rigidity of these portions would require appropriate fastening systems using screws, etc., making the opening and closing of the upper frame troublesome.
According to the construction of this invention, the vibration of the upper frame is absorbed by the gaps between the upper frame and the fulcrum shaft, and by low-rigidity portions where the upper frame makes contact with the stopper, and the vibration transmitted to the unit frame as a separate body from the upper frame that is supported by the fulcrum shaft and the stopper is also substantially attenuated. By providing the optical unit on this unit frame, therefore, aggravation of reading quality due to the vibration of the upper frame can be prevented.
Since the optical unit can be opened and closed around the fulcrum shaft, as in the case of the upper frame, adoption of t
Lee Cheukfan
PFU Limited
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