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Claims  |
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What is claimed is:
1. A picture image reader which reads picture image information in an
original by illuminating the original with light and by receiving the
transmitted or reflected light from the original, comprising:
(a) sensing means for reading picture image information by receiving the
light from the original which is illuminated;
(b) moving means for relatively moving said sensing means to the original;
(c) overlapping means for overlapping portions of reading picture images in
the picture image reading by said sensing means; and
(d) synthetic picture image formation means for synthesizing picture images
of the overlapped portion so as to obtain the picture images coinciding
with the picture images in the original, based on each of the picture
image information that is read by overlapping the picture images with said
sensing means.
2. A picture image reader as claimed in claim 1, in which said synthetic
picture image formation means comprises a weighting means for multiplying
each of the picture image information of the overlapped portion by
respective predetermined coefficients, and an adding means for summing the
multiplied picture image information.
3. A picture image reader as claimed in claim 2, in which said overlapping
means comprises a control unit for controlling said moving means so as to
have said sensing means read a portion of the picture image reading region
in an overlapped manner
4. A picture image reader which reads picture image information in an
original by illuminating the original with light and by receiving the
transmitted or reflected light from the original, comprising:
(a) sensing means for reading picture image information by receiving the
light from the original which is illuminated;
(b) moving means for relatively moving said sensing means to the original;
(c) overlapping means for overlapping portions of reading picture images in
the picture image reading by said sensing means; and
(d) synthetic picture image formation means for synthesizing picture images
of the overlapped portion so as to obtain the picture images coinciding
with the picture images in the original, based on each of the picture
image information that is read by overlapping the picture images with said
sensing means, said synthetic picture image formation means comprising a
weighting means for multiplying each of the picture image information of
the overlapped portion by respective predetermined coefficients, and an
adding means for summing the multiplied picture image information, said
overlapping means comprising a control unit for controlling said moving
means so as to have said sensing means read a portion of the picture image
reading region in an overlapped manner, said moving means comprising a
sensor transporting mechanism which lets said sensing means scan in a
first direction with respect to the original and an original transporting
mechanism which transports the original so as to let said sensing means
move in a second direction perpendicular to the first direction relative
to the original whenever said sensing means completes scanning in the
first direction, and the control unit controls the original transporting
mechanism to move the original in the second direction by a distance
smaller than the reading width in the second direction of said sensing
means so as to let said sensing means read the reading region of picture
images in an overlapped manner.
5. A picture image reader as claimed in claim 4, in which the sensor
transporting mechanism comprises a carriage for housing the sensing means
in its inside, guide rails for guiding the carriage in the first
direction, and a first motor for moving the carriage via a pulley and a
belt, the original transporting mechanism comprising rollers for holding
the original between them to feed it in the second direction and a second
motor for driving the rollers, and the control unit comprising a
microcomputer, I/O ports, and drivers for controlling the first motor so
as to move the sensing means scan in the first direction relative to the
original, as well as for controlling the second motor to move the original
in the second direction by a distance which is smaller than the reading
width Wr in the second direction of said sensing means so as to let said
sensing means read the reading region of picture images in overlapped
manner.
6. A picture image reader as claimed in claim 4, in which the weighting
means comprises at least two coefficient circuits for weighting each of
the picture image information of the overlapped portion by multiplying
them respectively with predetermined coefficients, and the adding means
comprising an adder for summing the weighted picture image information
obtained from each of the coefficient circuits.
7. A picture image reader as claimed in claim 6, in which said synthetic
picture image formation means further comprises a first gate for inputting
a preceding picture image information read by the n-th (n.gtoreq.1)
reading operation of the sensor, a second gate for inputting a succeeding
picture image information read by the (n+1)-th reading operation of the
sensor, a first line buffer for memorizing the picture image information
from the first gate in the second direction to outputting the
predetermined picture image information of the overlapped portion to the
first coefficient circuit, a second line buffer for memorizing the picture
image information from the second gate in the second direction to
outputting the predetermined picture image information of the overlapped
portion to the second coefficient circuit, and an output line buffer for
memorizing and outputting the picture image information of the
nonoverlapped portion from the first and second line buffers and the
picture image information of the overlapped portion from the adder.
8. A picture image reader as claimed in claim 1, in which said synthetic
picture image formation means comprises a division control means for
subdividing the overlapped portion into a plurality of narrowly stripped
regions, and an arranging means for arranging both picture image
information of the overlapped portion alternately in the area subdivided
into the plurality of narrow regions by the division control means.
9. A picture image reader as claimed in claim 8, in which the division
control means comprises a line counter and the arranging means comprising
a data selector.
10. A picture image reader as claimed in claim 4, in which said sensor
means comprises a rod array lens whose one end is arranged closely facing
the original, having an array construction long in the subscanning
direction with reading width of Wr, and a CCD sensor array which is
arranged in close contact with the other end of the rod array lens, having
an array construction, with reading width of Wr, consisting of a plurality
of sensors arranged in series in the second direction, similar to the rod
array lens.
11. A picture image reader as claimed in claim 4, in which said sensor
means comprises a first reading unit and a second reading unit, the first
reading unit consisting of a lens, a CCD sensor array, and a light source
for illumination, the second reading unit consisting of a lens, a CCD
sensor array, and a light source for illumination, and the first and
second reading units being arranged side by side in the first direction.
12. A picture image reader as claimed in claim 2, in which said sensing
means comprises an array of a plurality of line image sensors that are
constructed by arranging a plurality of photoelectric conversion elements
in a line, and said overlapping means comprising a rod array lens which is
arranged so as to have the images of a portion of the picture image of the
original overlapped on the line image sensors of at least two in number.
13. A picture image reader as claimed in claim 12, in which the weighting
means comprises at least two of coefficient ROM's for generating
predetermined coefficients and at least two of multipliers for multiplying
each of the picture image information for the overlapped portion by the
coefficients from the respective coefficient ROM's, and the adding means
comprising an adder for summing the weighted picture image information
from the respective multipliers.
14. A picture image reader which reads picture image information in an
original by illuminating the original with light and by receiving the
transmitted or reflected light from the original, comprising:
(a) sensing means for reading picture image information by receiving the
light from the original which is illuminated;
(b) moving means for relatively moving said sensing means to the original;
(c) overlapping means for overlapping portions of reading picture images in
the picture image reading by said sensing means; and
(d) synthetic picture image formation means for synthesizing picture images
of the overlapped portion so as to obtain the picture images coinciding
with the picture images in the original, based on each of the picture
image information that is read by overlapping the picture images with said
sensing means, said synthetic picture image formation means comprising a
weighting means for multiplying each of the picture image information of
the overlapped portion by respective predetermined coefficients, and an
adding means for summing the multiplied picture image information, said
sensing means comprising an array of a plurality of line image sensors
that are constructed by arranging a plurality of photoelectric conversion
elements in a line, said overlapping means comprising a rod array lens
which is arranged so as to have the images of a portion of the picture
image of the original overlapped on the line image sensors of at least two
in number, said weighting means comprising at least two of coefficient
ROM's for generating predetermined coefficients and at least two of
multipliers for multiplying each of the picture image information for the
overlapped portion by the coefficients from the respective coefficient
ROM's, and said adding means comprising an adder for summing the weighted
picture image information from the respective multipliers, the
coefficients .alpha. and .beta. of the two coefficient ROM's being set to
.alpha.=1 and .beta.=0 for the duration of the first half of one line in
which the picture image data A alone is effective, to .alpha.+.beta.=1 for
the duration at the middle of one line that corresponds to the overlapped
portion, and to .alpha.=0 and .beta.=1 for the duration of the latter half
of one line in which the picture image B alone is effective.
15. A picture image reader which reads picture image information in an
original by illuminating the original with light and by receiving the
transmitted or reflected light from the original, comprising:
(a) an optical sensor for reading picture image information by receiving
the light from the original which is illuminated;
(b) an optical sensor transporting mechanism which causes said optical
sensor scan in the first direction with respect to the original;
(c) an original transporting mechanism for transporting the original so as
to move the original in a second direction perpendicular to the first
direction relative to the original, whenever said optical sensor completes
scanning in the first diredction;
(d) a control unit for controlling the original transporting mechanism so
as to move the original in the second direction by a distance smaller than
the reading width Wr in the second direction of said optical sensor, in
order to let said optical sensor read the reading region of picture images
in the overlapped manner; and
(e) a synthetic picture image formation means for synthesizing a picture
image of the overlapped portion so as to have the picture image coincident
with the picture image in the original, based on each picture image
information that is read in overlapped manner by said optical sensor,
(f) said synthetic picture image formation means comprises at least two of
coefficient circuits for weighting through multiplication of each of the
picture image information of the overlapped portion with respective
predetermined coefficients, and an adder for summing the weighted picture
image information from each of the coefficient circuits.
16. A picture image reader which reads picture image information in an
original by illuminating the original with light and by receiving the
transmitted or reflected light from the original, comprising:
(a) an optical sensor formed by placing a plurality of line image sensors,
each constructed by arranging a plurality of photoelectric conversion
elements in a line, in the main scanning direction, in order to have the
images of a portion of the picture image in the original in overlaped
manner;
(b) a moving mechanism for relatively moving said optical sensor and the
original;
(c) a synthetic picture image formation mechanism for synthesizing picture
image for the overlapped portion so as to have the picture image
coincident with the picture image in the original, based on the picture
image information that is read overlapped by said optical sensor, and
(d) said synthetic picture image formation means comprises at least two of
coefficient ROM's for generating predetermined coefficients, at least two
of multipliers for multiplying each of the picture image information for
the overlapped portion with the coefficients from respective coefficient
ROM's, and an adder for summing the weighted picture image information
from each of the multipliers.
17. A picture image reader which reads picture image information in an
original by illuminating the original with light and by receiving the
transmitted or reflected light from the original, comprising:
(a) sensing means for reading picture image information by receiving the
light from the original which is illuminated;
(b) moving means for relatively moving said sensing means to the original;
(c) overlapping means for overlapping portions of reading picture images in
the picture image reading by said sensing means; and
(d) synthetic picture image formation means for synthesizing picture images
of the overlapped portion so as to obtain the picture images coinciding
with the picture images in the original, based on each of the picture
image information that is read by overlapping the picture images with said
sensing means, said synthetic picture image formation means comprising a
division control means for subdividing the overlapped portion into a
plurality of narrowly stripped regions, and an arranging means for
arranging both picture image information of the overlapped portion
alternately in the area subdivided into the plurality of narrow regions by
the division control means.
18. A picture image reader as claimed in claim 17, in which the division
control means comprises a line counter and the arranging means comprises a
data selector. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a picture image reader in facsimile, for
example, which reads the picture image information in a color original by
irradiating the original to be transmitted and by receiving the reflected
or transmitted light from the oringal.
2. Description of the Prior Art
In facsimile and others, for reading picture images of an original to be
transmitted, use is generally made of a solid sensor array consisting of
CCD sensor or the like with wide reading width that can read a plurality
of lines simultaneously. With such a device, there has been known a
reading method in which, as shown in FIG. 1, the picture image information
of the original 10 corresponding to the reading width of the sensor array
is scanned electronically or mechanically in a first direction, namely,
the main scanning direction, in one reading operation in the main scanning
direction. Then, the original is moved by a predetermined distance,
namely, by the amount of a pitch that corresponds to the reading width of
the sensor array, in the subscanning direction which is perpendicular to
the main scanning direction, to carry out the next reading operation in
the main scanning direction. The reading operation of the original for the
device consists of a repetition of the scanning operation as described in
the above.
Now, for reading picture images in the main scanning direction by means of
a sensor array, there are known also several other methods. Namely, a
method in which use is made of a reducing optical system whose lens is
utilized for illuminating the picture image reading area of the original,
as well as for focusing the picture images corresponding to the full
length in the main scanning direction by reducing the length, in order to
let the sensor array receive the reflected light from the picture image in
the original. Another is an erecting, unit-magnification, and contact
imaging method which supplies picture image information to the sensor
array via a rod lens array which is arranged to the full width in the main
scanning direction, with one end of the array facing the reading position
of the picture image of the original and the other end facing the sensor
array. Still another is a series reading method which reads the picture
image information by scanning the original in series successively in the
main scanning direction by moving the sensor array in the main scanning
direction. Here, the method of utilizing a reducing optical system and the
method of erect, unit-magnification, and contact imaging type are the
methods of scanning the original electrorically in the main scanning
direction. However, there are drawbacks such as, in the method of
utilizing a reducing optical system, the structure of the device becomes
bulky due to increase in the optical length for the lens, and in the
method of erect, unit-magnification, and contact imaging type, it becomes
costly due to the necessity of using a plurality of CCD sensors that
correspond to the width in the main scanning direction. In contrast, the
series reading method is a method in which scanning in the main scanning
direction is carried out mechanically, so that it has an advantage that
the device can be made compact and economical.
Hence, in constructing a color facsimile unit, it is desirable from the
viewpoint of economy and miniaturization to adopt the series reading
method which reads the picture image information in the original in
succession by scanning the original in series along the main scanning
direction while moving the sensor array in the main scanning direction.
However, the series reading method has a drawback in that the operation of
reading by scanning takes too long a time because it reads the picture
images by scanning the original in succession in continuous manner.
Moreover, in reading the original by scanning the original in the main
scanning direction, in one reading scan it reads the picture images in the
region that corresponds to the reading width of the sensor array, and in a
subsequent similar reading scan in the main scanning direction it reads
the picture images in the region that corresponds to the reading width of
the sensor array. In this way, in each reading scan it reads the picture
images that are located in the region corresponding to the reading width
of the sensor array. When each of the picture image information with a
width of region that is read in succession, is arranged in regular order
along the subscanning direction, it forms a reproduction of the original
picture images in the original. However, there is a problem that the
picture image information read by the sensor that is on one edge section
of the sensor array differs from that read by the sensor that is on the
other edge section, even if the same picture image is read by both of
them. This is due to the difference in characteristics of sensors on both
edge sections of a sensor array with fixed reading width, difference in
illumination and difference in precision of mechanism at both edge
sections, such as the difference in the distances from each of the sensor
on both edge sections to the original and the difference in shading
corrections. Because of this, if each picture image information read is
simply arranged in regular order in the direction of subscanning, there is
generated a discontinuity at each boundary of picture images, namely, at
the boundary of each main scanning. It then leads to a result that the
picture image is distorted unnaturally due to the discontinuity. In
particular, in the case of color picture images, there are generated not
only variable density in the picture image but also a difference in the
hue, so that the distortion becomes more conspicuous.
Further, there is another method, as shown in FIG. 2, in which picture
images are read by a plurality of line sensors 14 and 16 placed separated
in the direction of main scanning. In this method, the portion 19 of the
picture elements, which is the overlap between the two sensors, is
processed in which the two output signals for picture images that are
output from the sensors 14 and 16 are switched electrically to form one
line of continuous output signal for picture images, with an arbitrary
picture element in the overlapped picture elements as boundary.
However, according to the system, there are output picture image signals
that are different with the juncture as the boundary due to scatter in the
electrical characteristics (namely, nonlinear characteristics, offset, and
so forth) of each line of sensors, which produces a juncture in the
reproduced picture images.
Namely, human vision has a special feature that it has a very high ability
of detecting the relative difference between two images that are displayed
for comparison so that if the juncture of the output signals from the two
line image sensors becomes noticeable, then the image is perceived as a
band-like unevenness with width that corresponds to the length of the
sensors in the main scanning direction, which is an unsightly image.
In particular, human eyes are more sensitive to the difference in hue than
to the difference in brightness. Then, in a color image reader, if there
is a scatter in the electrical characteristics in the line image sensors
or a scatter in the spectroscopic characteristics of color filters that
are placed in front of each of line image sensor, then the juncture
between the output signals from the line image sensors becomes very
conspicuous. Since it is difficult to suppress these scatters to a low
level by selection or combination alone of image sensors or color filters,
there is a problem that the burden on the price is high also.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a picture image reader
which is capable of generating a picture image information that can
reproduce high quality picture images that do not give rise to distortions
in the boundary sections of the reading scans, obtained from the picture
images in the original by reading through scanning.
Another object of the present invention is to provide a picture image
reader which enables fast reading operation of the picture images in the
original.
In a picture image reader which reads the picture image information in the
original by receiving transmitted or reflected light from the original
which is illuminated, a special feature of the present invention lies in
that it comprises an optical sensor which reads picture image information
by receiving light from the original that is illuminated, an optical
sensor transporting mechanism which makes the optical sensor to scan in a
first direction relative to the original, an original transporting
mechanism which transports the original in a second direction that is
perpendicular to the first direction whenever the optical sensor completes
scanning in the first direction, at least two coefficient circuits
equipped with a control unit which controls the original transporting
mechanism so as to move the original in the second direction by a distance
which is less than the reading width W.sub.r of the optical scanner in the
second direction, in order for the optical sensor to be able to read the
picture image reading region in an overlapping manner, and a synthetic
picture image formation circuit which synthesizes images in the overlapped
section, in order to have images that coincide with those in the original,
based on each picture image information that is read by the optical sensor
in an overlapping manner, and the above-mentioned synthetic picture image
formation circuit weights each picture image information in the overlapped
section by multiplying it with a predetermined coefficient, and an adder
which adds the weighted picture image information that are sent from each
of the coefficient circuits.
These and other objects, features and advantages of the present invention
will be more apparent from the following description of the preferred
embodiments in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified diagram for illustrating one scanning method in the
reading operation that uses a sensor array;
FIG. 2 is a simplified diagram for illustrating the structure of the sensor
for another scanning method in the reading operation;
FIG. 3 is a perspective view of a color facsimile which employs a picture
image reader that embodies the present invention;
FIG. 4 is a block diagram for the control unit which controls the motors
and the fluorescent lamp shown in FIG. 3;
FIG. 5 is a disassembled perspective view of the carriage in the device
shown in FIG. 3;
FIGS. 6a and 6b are diagrams for illustrating the scanning method in the
device shown in FIG. 3;
FIG. 7 is a block diagram for the picture image synthetic processing
circuit in the first embodiment shown in FIG. 3;
FIG. 8 is a diagram for illustrating the operation of the picture image
synthetic processing circuit shown in FIG. 7;
FIG. 9 is a block diagram for a modification to the picture image synthetic
processing circuit in the first embodiment in accordance with the present
invention;
FIGS. 10a and 10b are the explanatory diagrams for illustrating the
operation of the picture image synthetic processing circuit shown in FIG.
9;
FIG. 11 is a simplified block diagram for the sensor section in a second
embodiment of the picture image reader in accordance with the present
invention;
FIG. 12 is a simplified diagram for illustrating the operation of the
second embodiment;
FIG. 13 is a block diagram for the second embodiment of the picture image
synthetic processing circuit of the present invention;
FIGS. 14a and 14b and FIG. 15 are diagrams for illustrating the operation
of the picture image synthetic processing circuit shown in FIG. 13;
FIG. 16 is a block diagram for a modification to the picture image
synthetic processing circuit in the second embodiment in accordance with
the present invention;
FIGS. 17a and 17b are diagrams for illustrating the operation of the
picture image synthetic processing circuit shown in FIG. 16;
FIG. 18 is a block diagram for a third embodiment of the picture image
synthetic processing circuit in accordance with the present invention;
FIG. 19 is a simplified diagram for illustrating the structure of the
sensor in the third embodiment shown in FIG. 18;
FIG. 20 is a diagram for illustrating the method of using memories in the
picture image synthetic processing circuit shown in FIG. 18;
FIGS. 21a to 21g are time charts for the picture image synthetic processing
operation;
FIGS. 22a to 22d are diagrams showing the patterns of picture image
synthetic processing;
FIG. 23 is a block diagram for a modification to the picture image
synthetic processing unit in the third embodiment;
FIG. 24 is a block diagram for another modification to the picture image
synthetic procssing unit in the third embodiment; and
FIG. 25 is a block diagram for still another modification to the picture
image synthetic processing unit in the third embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 3, there is shown a color facsimile unit employing a
picture image reader embodying the present invention, with reference
numeral 20. In the color facsimile unit 20, both ends of the main body 22
are bent upward to form the side wall sections 24a and 24b. Supported its
both ends between the upper edges of the side wall sections 24a and 24b is
a fluorescent lamp 26. Underneath and parallel to the fluorescent lamp 26
there are supported a pair of guide rails 28a and 28b that are separated
in parallel by a predetermined distance. At around the middle of these
guide rails 28a and 28b there is arranged a carriage 30 that is housing a
rod array lens and CCD sensor in its inside, for reading the picture image
information. Further, on the carriage 30 there is fixed with screws or
others a belt 32 which extends parallel to the guide rails 28a and 28b,
and the belt 32 is wound around a pair of pulleys 34a and 34b that are
arranged at left and right sides of the areas near the side wall sections
24a and 24b. The central part of the left-side pulley 34a is linked to the
drive shaft of a motor 36 which is controlled by a control unit that will
be described later. When the motor rotates, the pulley 34a is rotated to
move the belt 32, and by this action, the carriage 30 is moved and scans
the area between the side wall sections 24a and 24b in the main scanning
direction along the guide rails 28a and 28b. Between the side wall
sections 24a and 24b of the main body 22 and below the carriage 30 is
arranged an original to be transmitted, opposing the bottom surface of the
carriage 30. The edges of the original 38 are held between the original
feeding rollers 42 and 42' that are arranged freely rotatably across the
side wall sections 24a and 24b of the main body, and are set to be driven
to rotate by a motor 40 that is controlled by the control unit, as will be
described later. When the rollers 42 and 42' are rotated, the original 38
that is being held between the rollers 42 and 42' is fed in the
subscanning direction which is perpendicular to the main scanning
direction, that is, in the direction toward the rear of the main body 22
in FIG. 3. Moreover, directly beneath the fluorescent lamp 26 there is
arranged a platelike light-guiding member 44, made of a rectangular
transparent material, that is supported in parallel to the fluorescent
lamp 26, extending between the side wall sections 24a and 24b. One end
surface of the longitudinal direction of the platelike light-guiding
member 44 faces the fluorescent lamp 26 at a close distance, while its
opposite end is positioned between the carriage 30 and the original 38.
With this arrangement, light from the fluorescent lamp 26 impinges upon
the inside of the light-guiding member 44 through one of its ends that
faces the fluorescent lamp 26, and is set to irradiate the picture image
reading area of the original 38 which is placed beneath the carriage 30,
from the other end via the light-guiding member 44.
Referring to FIG. 4, there is shown a control unit 47 which consists of a
microcomputer 43, I/O ports 45, and drivers 46. With the control unit 47,
the operations of the motor 36 that moves the carriage 30, the motor 40
that moves the original, and the fluorescent lamp 26 are controlled.
The carriage 30 consits, as shown by a disassembled perspective view, FIG.
5, of a rod array lens 48 that has an array structure which is long in the
subscanning direction with a reading width Wr, having one of its ends
arranged to face the original 38 at a close distance, a CCD sensor array
50 which is arranged to make a close contact with the other end of the rod
array lens 48, having an array structure consisting of a plurality of
sensors that are arranged long in series in the subscanning direciton,
with reading width Wr, similar to the rod array lens 48, for reading
picture image information from the original 38 via the rod array lens 48,
a connector 52 connected to the CCD sensor array 50, and a carriage case
54 which houses each of these parts. The picture image information of the
original 38 that is read by the CCD sensor array 50 via the rod array lens
48 is provided from the connector 52 to the picture image synthetic
processing circuit that will be described later. Since the CCD sensor
array 50 and the rod array lens 48 have, as shown in the figure, a reading
width Wr which is long in the subscanning direction, when they are moved
by the belt 32 as mentioned earlier to scan to read the picture images of
the original 38 in the main scanning direction, it is possible to read at
once the picture images in the region that corresponds to the reading
width Wr in one operation.
In a picture image reader that is constructed as in the above, when the
carriage 30 is moved in the main scanning direction to read the picture
image information in the original 38 via the pulleys 34a and 34b and the
belt 32 by the roataion operation of the motor 36 under the control of the
control unit 47, light from the fluorescent lamp 26 is transmitted via the
light-guiding member 44 to illuminate the picture image reading area of
the original 38 that faces the bottom section of the carriage 30. As a
result, the reflected light from the picture image of the original 38 that
is illuminated by light through the light-guiding member 44 is detected by
the CCD sensor array 50 via the rod array lens 48, and the picture images
in the region that corresponds to the reading width Wr are read at once.
When the carriage 30 completes the reading and scanning action from one end
to the other end of the main scanning direction by the rotation of the
motor 36, the carriage 30 is brought back to the original position by the
action of reverse motion of the motor 36. At the same time, the original
is sent out by a fixed distance in the subscanning direction by the
rotation action of the rollers 42 and 42' for feeding the original. When
the feeding action in the subscanning direction is completed, there will
be started again by the motor 36 the reading action through the carriage
30 in the main scanning direction, and similar operation will be repeated
thereafter. The picture image information that is read by the CCD sensor
array 50 in the repeated reading operation is supplied to the picture
image synthetic processing unit that will be described later.
In this case, after picture images in the region that corresponds to the
reading width Wr are read in one scanning operation of the CCD sensor
array of the carriage 30 in the main scanning direction, and the original
38 is fed in the subscanning direction by the action of the rollers 42 and
42' for feeding original, if the distance of feeding equals the length
corresponding to the reading width Wr, then all of the picture images will
be read completely without missing any. In this embodiment, however,
feeding length of the original 38 is controlled via the motor 40 and the
rollers 42 and 42' to be less than the length that corresponds to the
reading width Wr. In this way, it is designed to read the same image
portion 52 once in one reading operation in the main scanning direction
and again in the next scanning operation in the main scanning direction,
as shown in FIG. 6. Namely, after first reading operation with reading
width Wr is done as shown by FIG. 6a, second reading operation is carried
out so as to have an overlapped portion of picture image 52 as shown by
FIG. 6b. With such an arrangement, all the reading operations will have
overlapped portions. Therefore, by forming synthesized images by applying
processings that will be described later to the overlapped sections 52,
the present invention aims at removing the distortion in the picture
images that used to be generated at the boundaries of each operation of
reading by scanning.
Referring to FIG. 7, there is shown a picture image synthetic processing
circuit for forming synthesized picture images at the overlapped sections
that represent the boundaries of the picture image scannings. In FIG. 8,
there is shown a diagram for illustrating the operation of the circuit.
As shown in FIG. 7, a preceding picture image information that is read in a
first reading operation is memorized via a gate 55 in a line buffer 56
which consists, for instance, of a flip-flop or a memory circuit.
Similarly, a succeeding picture image information that is read in a second
reading operation is memorized in a line buffer 60 via a gate 58. The
picture image information that is memorized in the line buffer 56 or the
line buffer 60 is that which is read by the CCD sensor 50 with reading
width Wr in one operation of the carirage 30 in the main scanning
direction. Each of the line buffers 56 and 60 memorizes the picture image
information in the direction of reading width of the sensor array 50
(namely, the subscanning direction). Therefore, the picture image
information S56 and S60 (see FIG. 8) that are output from each line
buffers 56 and 60 are output in parallel in the direction of the reading
width. In the picture image information S56 and S60 shown in FIG. 8, the
abscissas correspond to the direction of the reading width, while the
ordinates show the levels of the picture image information that are output
from the line buffers 56 and 60. As to the preceding picture image
information S56 that is memorized in the line buffer 56, there are given
hatches on the right-hand end sections of the line buffer 56 in FIG. 7 and
the picture image information S56 in FIG. 8. For the succeeduing picture
image information S60 that is memorized in the line buffer 60, there are
given hatches on the left-hand end sections of the line buffer 60 in FIG.
7 and the picture image information S60 in FIG. 8. These hatched portions
represent, as mentioned above, the overlapped picture image portion 52 in
the direction of the reading width, between the first reading operation
and the second reading operation.
In FIG. 7, the picture image information from the predetemrined portion
(hatched portion) in the line buffer 56 is supplied to a first coefficient
circuit 62, and the remaining picture image information of the line buffer
56 is supplied directly to the output line buffer 64 without going through
the coefficient circuit 62. Similarly, the picture image information from
the predetermined overlapped portion (hatched portion) in the line buffer
60 is supplied to a second coefficient circuit 66, and the other picture
image information is supplied directly to the output line buffer 64
without going through the coefficient circuit 66. The outputs from the
coefficient circuits 62 and 66 are added in an adder 70 to be supplied to
the output line buffer 64. Each of the coefficient circuits 62 and 66
weights the picture image information of the overlapped portion supplied
respectively by the line buffers 56 and 60 with predetermined coefficients
K62 and K66. By adding and averaging in the adder 70 the weighted
quantities obtained by the multiplication with the coefficients K62 and
K66, the present invention aims at eliminating unnatural sight from the
boundaries in the picture image information by obtaining picture image
information that coincides with the picture images in the original.
For that purpose, the first coefficient circuit 62 possesses a coefficient
K62, as shown in FIG. 8, which is sloped down gradually toward right in
the reading width direction of the figure. Further, the second coefficient
circuit 66 possesses, as shown by FIG. 8, a coefficient K66 which slopes
down gradually toward left in the reading width direction of the figure,
opposite to the previous case of the coefficient K62. Consequently, the
picture image information for the overlapped portion from the line buffers
56 and 60 that are processed in each coefficient circuits 62 and 66
undergo next the processing according to the coefficients K62 and K66, and
are represented as the picture image information S62 and S66, as hatched
in FIG. 8. The picture image information S62 and S66 from the coefficient
circuit 62 and 66 that are coefficient processed in this manner are added
in the adder 70. They are synthesized so as to coincide with the picture
images in the original, as shown by picture image information S64 of FIG.
8, without any apparent unnatural look at the boundaries between each
picture image information. The picture image information synthesized in
this way is supplied from the adder 70 to the output line buffer, and is
inserted between the picture image information for the unoverlapped
portions that are supplied directly from the line buffers 56 and 60.
Referring to FIG. 9, there is shown a modification to the picture image
synthetic processing circuit in the first embodiment of the picture image
reader in accordance with the present invention. In the first embodiment
shown in FIG. 7, coefficient circuits and an adder are employed to
synthetically process the picture images in the overlapped portion by
weighting and averaging. In contrast, in the present embodiment, the
preceding picture image information from the line buffer 56 and the
succeeding picture image information from the line buffer 60 are
alternately interposed with relatively small width, to form synthetic
images by the use of a data selector 74 and a line counter 76.
Namely, as shown in FIG. 10a, the overlapped portion 52 between a preceding
picture image information that was obtained in a first reading operation
and a succeeding picture image information that was read in a second
reading operation, is divided, as shown in FIG. 10b, into a plurality of
regions with small width in the reading width direction (that is, in the
subscanning direction). By controlling the data selector 74 with the line
counter 76, the preceding picture image information from the line buffer
56 and the succeeding picture image information from the line buffer 60
are taken out for each region in turn, to be supplied to the line buffer
64. In this manner, the picture image for the overlapped section is formed
synthetically by alternately interposing narrow strips of the preceding
picture image and the succeeding picture image.
By sy | | |
