U.S. patent application number 09/110143 was filed with the patent office on 2002-05-16 for image reading apparatus.
Invention is credited to ITO, YOSHINORI, USAMI, AKIHIRO.
Application Number | 20020057853 09/110143 |
Document ID | / |
Family ID | 16248332 |
Filed Date | 2002-05-16 |
United States Patent
Application |
20020057853 |
Kind Code |
A1 |
USAMI, AKIHIRO ; et
al. |
May 16, 2002 |
IMAGE READING APPARATUS
Abstract
Two or more original illumination units are mounted on an image
reading apparatus. In reading a patched original, an image read
while being illuminated along one direction is compared with an
image read while being illuminated along another direction or along
two directions including the one direction and another direction.
In accordance with an image data difference between the two images,
image processing or illumination light amount changing is performed
to erase shades to be caused by a patched portion of the
original.
Inventors: |
USAMI, AKIHIRO;
(YOKOHAMA-SHI, JP) ; ITO, YOSHINORI;
(KAWASAKI-SHI, JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Family ID: |
16248332 |
Appl. No.: |
09/110143 |
Filed: |
July 6, 1998 |
Current U.S.
Class: |
382/312 |
Current CPC
Class: |
H04N 1/4097 20130101;
H04N 1/00795 20130101; H04N 1/00827 20130101; G09B 21/003
20130101 |
Class at
Publication: |
382/312 |
International
Class: |
G06K 009/20 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 15, 1997 |
JP |
9-189856 |
Claims
What is claimed is:
1. An image reading apparatus comprising: illuminating means for
illuminating an original recorded with an image along a plurality
of directions; reading means for optically reading the illuminated
original; and controlling means for controlling to said reading
means to read the original a plurality of times and controlling
said illuminating means in accordance with a sequential number of a
reading order.
2. An image reading apparatus according to claim 1, wherein said
controlling means controls said illuminating means to illuminate
the original along one direction at reading of one sequential
number of the reading order, and to illuminate the original along
another direction at reading of another sequential number of the
reading order.
3. An image reading apparatus according to claim 1, wherein said
controlling means controls said illuminating means to illuminate
the original along one direction at reading of one sequential
number of the reading order, and to illuminate the original along a
plurality of directions including the one direction at reading of
another sequential number of the reading order.
4. An image reading apparatus according to claim 2, further
comprising correcting means for correcting shades on the original
in accordance with each image signal obtained at reading of each
sequential number of the reading order.
5. An image reading apparatus according to claim 2, wherein said
controlling means acquires information representative of shades on
the original in accordance with each image signal obtained at
reading of each sequential number of the reading order, and
controls said reading means to further read the original in
accordance with the acquired information while controlling said
illuminating means to increase an illumination light amount for the
shades on the original.
6. An image reading apparatus according to claim 3, further
comprising correcting means for correcting shades on the original
in accordance with each image signal obtained at reading of each
sequential number of the reading order.
7. An image reading apparatus according to claim 3, wherein said
controlling means acquires information representative of shades on
the original in accordance with each image signal obtained at
reading of each sequential number of the reading order, and
controls said reading means to further read the original in
accordance with the acquired information while controlling said
illuminating means to increase an illumination light amount for the
shades on the original.
8. An irregularly raised pattern reading apparatus comprising: a
sheet member placed on an original recording with an irregularly
raised pattern and made of a flexible material; and signal
generating means for generating an electrical signal corresponding
to the irregularly raised pattern reflected upon a surface of said
sheet member.
9. An irregularly raised pattern reading apparatus according to
claim 8, wherein said signal generating means comprises: a
plurality of striped first conductors disposed in parallel on a
surface of said sheet member; a roller disposed above said striped
first conductors by a predetermined gap and having an axial
direction perpendicular to said striped first conductors, said
roller being capable of rotating and moving along an extension
direction of said striped first conductors; a plurality of striped
second conductors disposed on a circular surface of said roller in
parallel with each other, one of said striped second conductors
being selectively made in contact with one of the striped first
conductors when said sheet member is deformed by the irregularly
raised pattern on the original; and terminal means connectable to
one of said striped second conductors being selectively connected
to one of said striped first conductors.
10. An irregularly raised pattern reading apparatus according to
claim 8, wherein said signal generating means includes a plurality
of pressure sensors disposed on the surface of said sheet member
and being operated when said sheet member is deformed by the
irregularly raised pattern on the original.
11. An irregularly raised pattern reading apparatus comprising
switch means including a plurality of switches mounted on a surface
in contact with an original recorded with an irregularly raised
pattern and operated in response to the irregularly raised pattern
on the original, said switch means generating an electrical signal
in accordance with a state of each of said plurality of switches.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an image reading apparatus
such as a scanner for reading an original on which images are
recorded.
[0003] 2. Related Background Art
[0004] An illumination apparatus of a conventional image reading
apparatus such as a scanner has been designed to equalize the
intensities of light from both the upstream and downstream sides of
an original (5:5 illumination) in order to erase shades to be
caused by an original illumination direction when a patched
original is read.
[0005] FIG. 13 illustrates the principle of illumination. An
original 201 has a patched original 202 pasted thereon. This
original 201 is placed on a glass mount 203 and illuminated with
two illumination units 204 and 205 from a lower position along
opposite directions. In this case, although illumination with the
illumination unit 205 does not produce a shade on the right side of
the patched original, illumination with the illumination unit 204
produces a shade 206 on the original 201 because of the presence of
the patched original 202.
[0006] To avoid this, a highlight area of an image has been
conventionally set rather dark by image processing or the like to
erase shades from the image, or in a copier machine, the highlight
area of an image has been conventionally set rather dark by an
image forming process to erase shades.
[0007] However, recently, user requirements for the reproduction of
a highlight area with an image reading apparatus are becoming
severe, and even the highlight area is desired to be reproduced
with fidelity. However, if an apparatus is designed to reproduce
even the highlight area, shades are produced when a patched
original or the like is read. With conventional techniques, the
reproduction of highlight areas and the erasure of shades are
contradictory with each other.
[0008] An image forming apparatus is prevailing which reads an
image of an original with an optical sensor and the read image of
the original is subjected to various image processing to record it
on a recording sheet. However, although a conventional image
forming apparatus can optically read color information recorded on
an original, it cannot read an original with an irregularly raised
pattern such as points of braille characters in monochrome
color.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide an image
reading apparatus capable of satisfying both the reproduction of
highlight areas and the erasure of shades.
[0010] It is another object of the present invention to provide an
apparatus capable of reading irregularly raised pattern
information.
[0011] According to one embodiment of the invention, an image
reading apparatus capable of satisfying both the reproduction of
highlight areas and the erasure of shades is provided which
comprises illuminating means for illuminating an original recorded
with an image along a plurality of directions, reading means for
optically reading the illuminated original, and controlling means
for controlling to the reading means to read the original a
plurality of times and controlling the illuminating means in
accordance with a sequential number of a reading order.
[0012] According to another embodiment of the invention, an
irregularly raised pattern reading apparatus is provided which
comprises a sheet member placed on an original recording with an
irregularly raised pattern and made of a flexible material, and
signal generating means for generating an electrical signal
corresponding to the irregularly raised pattern reflected upon a
surface of the sheet member.
[0013] By placing the sheet member on an original recorded with the
irregularly raised pattern such as braille characters and
three-dimensional lines, it is possible to read the irregularly
raised pattern and obtain electrical signals corresponding to the
irregularly raised pattern.
[0014] According to another embodiment of the invention, an
irregularly raised pattern reading apparatus is provided which
comprises switch means including a plurality of switches mounted on
a surface in contact with an original recorded with an irregularly
raised pattern and operated in response to the irregularly raised
pattern on the original, the switch means generating an electrical
signal in accordance with a state of each of the plurality of
switches.
[0015] Since a plurality of switches is selectively turned on or
off in accordance with the irregularly raised pattern, electrical
signals corresponding to the irregularly raised pattern can be
obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows the structure of an image reading apparatus
according to a first embodiment of the invention.
[0017] FIG. 2 is a block diagram showing the structure of a control
unit.
[0018] FIG. 3 is a flow chart illustrating an image reading
operation.
[0019] FIGS. 4A and 4B illustrate an operation of reading a patched
original.
[0020] FIG. 5 is a block diagram showing the structure of an image
processing unit.
[0021] FIGS. 6A and 6B illustrate CCD outputs.
[0022] FIG. 7 is a flow chart illustrating the operation by an
image comparison unit.
[0023] FIG. 8 is a flow chart illustrating the operation of an
image comparison unit according to a second embodiment of the
invention.
[0024] FIG. 9 shows the structure of illumination units according
to a third embodiment of the invention.
[0025] FIG. 10 shows another structure of the illumination units of
the third embodiment.
[0026] FIG. 11 is a block diagram showing the structure of an image
processing unit.
[0027] FIG. 12 shows the connection between a scanner and a host
computer.
[0028] FIG. 13 shows the structure of a conventional image reading
apparatus.
[0029] FIG. 14 is a perspective view of an image forming apparatus
according to an embodiment of the invention.
[0030] FIG. 15 is a schematic flow diagram illustrating the
operation of the image forming apparatus, from reading a normal
image original to outputting a copy of the original.
[0031] FIG. 16 is a schematic flow diagram illustrating the
operation from reading a braille original and to outputting a copy
of translation results, according to a fourth embodiment of the
invention.
[0032] FIG. 17 is a schematic diagram showing the structure of an
irregularly raised pattern reading apparatus of the fourth
embodiment.
[0033] FIG. 18 is a diagram illustrating the operation of detecting
a raised portion by the irregularly raised pattern reading
apparatus of the fourth embodiment.
[0034] FIG. 19 is a diagram illustrating an example of reading a
braille original according to the fourth embodiment.
[0035] FIGS. 20A and 20B illustrate an operation of fetching one
braille character.
[0036] FIG. 21 is a diagram showing a braille conversion
reference.
[0037] FIGS. 22A and 22B are diagrams illustrating how braille
characters are translated.
[0038] FIG. 23 is a diagram showing the structure of an irregularly
raised pattern reading apparatus according to a fifth embodiment of
the invention.
[0039] FIG. 24 is a diagram showing the structure of an irregularly
raised pattern reading apparatus according to a sixth embodiment of
the invention.
[0040] FIG. 25 is a schematic flow diagram illustrating the
operation of the irregularly raised pattern reading apparatus of
the sixth embodiment, from reading braille characters to forming an
image of translation results.
[0041] FIGS. 26A and 26B show the structure of an irregularly
raised pattern reading apparatus according to a seventh embodiment
of the invention.
[0042] FIGS. 27A and 27B illustrate the operation of the apparatus
of the seventh embodiment, reading a braille original as a binary
image.
[0043] FIG. 28 shows the structure of an irregularly raised pattern
reading apparatus according to an eighth embodiment of the
invention.
[0044] FIGS. 29A and 29B illustrate the operation of forming an
image of a geometrical figure constituted of three-dimensional
lines.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] FIG. 1 shows an image reading apparatus according to the
first embodiment of the invention. In FIG. 1, elements same as
those shown in FIGS. 29A and 29B are represented by using identical
reference numerals, and the duplicated description is omitted.
[0046] Illumination units 204 and 205 are made of halogen lamps.
Reference numerals 206, 207 and 208 represent scanning mirrors
which are accommodated in an unrepresented optical scanning unit.
As this unit reciprocally moves, light reflected from an original
201 is introduced to a CCD unit 209.
[0047] The CCD unit 209 is constituted of a CCD 210 as an image
pickup element, a CCD driver 211, and a lens 212 for focussing
light reflected from the scanning mirror 208 onto CCD 210. An image
signal output from CCD 210 is converted into digital image data of
8 bits and input to a control unit 213. An illumination control
unit 214 controls the illumination units 204 and 205 in accordance
with an output from the control unit 213.
[0048] FIG. 2 shows the structure of the control unit 213.
Reference numeral 215 represents a CPU which controls the entirety
of the apparatus by sequentially reading and executing a control
procedure (control programs) stored in a ROM (read-only memory)
216. Address and data buses of CPU 215 are connected to respective
loads via a bus driver and address decoder 217. Reference numeral
218 represents a RAM (random access memory) as a main storage used
for storing input data, as working areas and the like. Reference
numeral 219 represents an I/O interface which is connected to
respective loads including a motor and the like 220 for driving an
optical system, the illumination control unit 214, a solenoid and
the like 221. Reference numeral 222 represents an image processing
unit. An image signal output from the CCD unit 209 is input to this
image processing unit 222 which performs image processing to be
described later and outputs the results to a host computer 223 and
to other units.
[0049] FIG. 3 is a flow chart illustrating the operation of the
apparatus of this embodiment, FIGS. 4A and 4B illustrate the
operation of reading an original 201 with a patched original 202,
and FIG. 5 is a block diagram showing the structure of the image
processing unit 222 shown in FIG. 2.
[0050] A first original scan is performed at Step 224 shown in FIG.
3. In this case, as shown in FIG. 4A, the original 201 is
illuminated only with the illumination unit 204. Light entered CCD
210 during this original scan is converted into an electrical image
signal. This image signal is converted by an A/D converter 229 into
image data whose uneven illumination or the like of the original is
corrected by a shading correction unit 230 and thereafter it is
stored in a memory 231 (Step 225).
[0051] Next, at Step 226 a second original scan is performed. In
this case, as shown in FIG. 4B, the original 201 is illuminated
only with the illumination unit 205.
[0052] FIGS. 6A and 6B illustrate a difference of an output of CCD
210 between the first and second original scans.
[0053] Since the first original scan uses only the illumination
unit 204, a CCD output lowers at a shade portion 241, whereas since
only the illumination unit 205 is used at the second original scan,
no shade is produced.
[0054] Next, at Step 227, image data stored in a memory 231 is
sequentially read and an image comparison processing unit 232
executes the processes illustrated in FIG. 7 which correspond to
the processes to be executed by CPU 215 shown in FIG. 2.
[0055] I1(i, j) at Step 233 is image data obtained at the first
original scan, and I2(i, j) at Step 234 is image data obtained at
the second original scan. For example, a white area of the original
is I=255, and a black area is I=0. At Step 235 if I1(i,j) -I2(i, j)
is larger than a predetermined threshold value SO (>0), I1(i,j)
is used as an output image signal O(i,j) (Step 236). If I2(i,j)
-I1(i,j) is greater than the predetermined threshold value SO
(>0) (Step 237), I2(i, j) is used as the output image signal
O(i, j) (Step 238). If not at Step 237, {I1(i,j)+I2(i, j)}/2 is
used as the output image signal O(i,j) (Step 239). These output
image signals are supplied to a personal computer, a network, and a
printer.
[0056] In the first embodiment, only the illumination unit 205 is
used at the second original scan as shown in FIG. 4B. In the second
embodiment of the invention, both the illumination units 204 and
205 are used at the second original scan. In this case, the
processes shown in FIG. 7 may be used.
[0057] However, since the light amount by one illumination unit is
a half that by both the illumination units, an S/N ratio may become
poor (a white area of the original with one and both illumination
units takes the same signal, for example, 255 of 8 bits, because of
the shading correction). In such a case, the image signal obtained
with both the illumination units may be used as illustrated in FIG.
8.
[0058] At Steps 240 and 241, the first and second original scans
are performed to obtain image data. Next, at Step 242, a difference
between the image data is compared with a threshold value S1. This
threshold value S1 may take a negative value when noises are
considered.
[0059] If a difference of I2(i,j) -I1(i,j) is larger than Si,
I2(i,j) is used as the output image signal O(i,j) (Step 243),
whereas if not, I1(i, j) is used as the output image signal O(i,j)
(Step 244).
[0060] In the first and second embodiments, shades are erased by
image processing. In the third embodiment of the invention, shades
are erased by controlling an illumination light amount applied to
an original. In this embodiment, the third original scan is
performed. In this third original scan, the illumination control
unit 214 shown in FIG. 1 increases the light amount of the
illumination unit which does not produce shades at a shade position
identified by the shade information obtained in the first and
second embodiments.
[0061] Instead of using a halogen lamp as the illumination unit,
fluorescent lamps 245 and 246 may be used as shown in FIG. 9, or
LED arrays 247 and 248 in combination with short focal length lens
arrays 249 and 250 may also be used as shown in FIG. 10. In the
case of fluorescent lamps and LED arrays, the fluorescent lamps 245
and 246 shown in FIG. 9 and the LED arrays 247 and 248 shown in
FIG. 10 can be alternately turned on by synchronizing the CCD
storage time with an illumination time.
[0062] In this case, the image processing unit 222 has the
structure as shown in FIG. 11. As shown, the memory 231 shown in
FIG. 5 may be replaced by a line memory 251 such as a FIFO,
resulting in a low cost.
[0063] If a color image reading apparatus is used, the operations
similar to the above are performed for each of RGB signals.
[0064] For the shade erasure, as shown in FIG. 12, image data of
two sheets obtained by illumination in opposite directions may be
read with a scanner 252 and supplied to a host computer 223 which
in turn executes the processes shown in FIGS. 7 and 8.
[0065] FIG. 14 shows an image forming apparatus according to the
fourth embodiment of the invention. This image forming apparatus
shown as a perspective view in FIG. 14 is a digital copier equipped
with a braille original reading apparatus.
[0066] The digital copier 10 is constituted of mainly two
parts.
[0067] The first main part is an image scanner 11 (hereinafter
abbreviated as "reader") mounted on an upper region of the copier,
the reader reading an original and outputting digital image data.
The reader 11 has therein a controller 13 which performs various
image processing of the digital image data, controls the reader 11
itself and a printer 12 to be described later, and interfaces with
external apparatuses. The reader 11 has an original cover 14
functioning as a lid for pressing an original placed on an original
glass mount 17.
[0068] The second main part is the printer 12 mounted under the
reader 11, the printer 12 printing an image on a recording sheet in
accordance with the digital image data supplied from the controller
13.
[0069] If an original 18 is a normal image original, it is placed
on the original glass mount 17 with its image surface facing the
mount 17. The printer 12 has a mechanism under the original glass
mount 17, the mechanism reading image data with an unrepresented
optical sensor. If the original is a braille original, it is placed
directing the braille surface upward. The reader 11 has a mechanism
of reading irregularly raised pattern data on the original with an
irregularly raised pattern reader 15 which is mounted on the
original glass mount 17 side of the original cover 14.
[0070] On one side of the reader 11, an operation unit 16 is
mounted being connected to the controller 13. A user enters various
information, operation commands and the like via the operation unit
16 into the copier. In accordance with the information entered from
the operation unit 16, the controller 13 controls the operations of
the reader 11 and printer 12.
[0071] Also entered by a user from the operation unit 16 to the
controller 13 is a command for switching a normal mode of reading a
normal original with color images formed on the recording medium to
a braille mode of reading a braille original formed with
irregularly raised patterns.
[0072] The printer 12 may be an ink jet printer having an ink jet
recording head, an electrophotographic laser printer or the like,
which can print image data supplied from the controller 13 on a
recording medium such as a recording sheet and an OHP sheet.
[0073] This copier 10 operates as illustrated in FIG. 15 in the
ordinary mode. Specifically, the optical scanner built in the
scanner 11 reads image data on an original 20 (Step 21). The
controller 13 performs image processing of the read image data,
such as input masking and black character processing (Step 22). The
processed image data is supplied to the printer 12 to form an image
on a print sheet (Step 23) and output a copy 24.
[0074] As a user switches the operation mode to the braille mode by
using the operation unit 16, the operation illustrated in FIG. 16
is performed. Specifically, an input apparatus is switched from the
optical scanner to the irregularly raised pattern reading apparatus
15 to convert a braille original 30 into image data and read it as
a binary image (Step 31). Each braille character is fetched (Step
32) to recognize it through pattern matching (Step 33), and
thereafter each read braille character is replaced by an image of a
normal character having generally the same size, by using a font
(Step 34). An image constituted of a normal character is supplied
to the printer 12 which prints it on a recording sheet (Step 35) to
thereby form a translated image copy 36. In the above manner, a
braille character is translated into an ordinary character image
which can be read by novices of braille characters.
[0075] FIG. 17 shows the structure of the irregularly raised
pattern reading apparatus 15 used with the copier of this
embodiment.
[0076] As shown in FIG. 17, a press sheet 40 made of flexible
material is used for pressing an original and is fixed at its four
sides with a housing of the original cover 14. The press sheet 40
has a number of fine stripe conductors 41 (conductors A) disposed
in parallel. Each conductor A 41 has terminals 42 which are
represented by A1, A1, A3, . . . , starting from the deepest
ones.
[0077] Also shown in FIG. 17, a rod-like roller 43 is placed on the
press sheet 40, with its axis being perpendicular to the conductor
A 41. The roller 43 is rotatively supported by bearings 46. In the
normal state, there is a small clearance 44 between the roller 43
and sheet 40. Eight fine stripe conductors 45 (referred to as a
conductor B) are formed on the circular surface of the roller 43
and are disposed at an equal pitch along the circumferential
direction of the roller 43. A conductive wire 47 is inserted into
the bearing 46 of the roller 43, one end of the wire being adapted
to be made in contact with each of the conductors B 45 and the
other end being connected to one terminal B 48.
[0078] The operation of the irregularly raised pattern reading
apparatus will be described.
[0079] The roller 43 is moved to the right and left by a drive
mechanism constituted of an unrepresented motor and the like, and
as the roller 43 is moved, the surface of the roller 43 near at the
conductor A 41 rotates in a direction opposite to the motion of the
roller 43. For example, assuming that the roller 43 moves to the
right as viewed in FIG. 17, it rotates in the right direction
(clockwise direction). At the start of reading a braille original,
the roller 43 is at the leftmost position of the sheet 40. In this
state, one of the conductor B 45 is in contact with the terminal B
48. As the read operation starts, the roller 43 moves to the right
and rotates in the right direction. As the roller 43 moves to the
right by a distance 49 between two conductors B 45, the next
conductor B 45 becomes in contact with the conductor B 48. Namely,
as the roller 43 moves, the conductor B 45 becomes in contact with
each of the conductor B 48 at an interval of the distance 49, thus
defining coordinate values which are represented by B1, B2, B3, . .
. , starting from the leftmost side of the sheet 40.
[0080] As shown in FIG. 18, as a braille original 51 is set, the
conductor A 41 on the sheet 40 is lifted by a raised braille
character. Since the sheet 40 and conductors 41 are sufficiently
flexible and deformed, only a raised portion of a braille original
is lifted, and a recess portion is maintained unlifted.
[0081] The conductor A 41 lifted by the raised portion becomes in
contact with the lowest conductor B 45 of the roller 43. In this
case, the terminal A 42 connected to the lifted conductor A 41 is
electrically connected to the terminal B 48, it is possible to
detect that a raised portion is present at the coordinate point of
the original corresponding to the cross point between the
conductors B 45 and A 42.
[0082] As the roller 43 is scanned from the leftmost to the
rightmost, raised portions of the original can be identified as
indicated by black points in FIG. 19. Assuming that the positions
B1, B2, B3, . . . are x-coordinate values, and the positions A1,
A2, A3, . . . are y-coordinate values, the black points shown in
FIG. 19 correspond to on-pixels of a binary image. In the above
manner, a braille original is read and a binary image process is
performed. As above, the structure of this embodiment is
substantially the same as a number of switches disposed at
coordinate points of the x- and y-coordinate system.
[0083] Next, a process of fetching each braille character from the
binary image of braille original data will be described. Reference
numeral 71 in FIG. 20A represents a binary image of a braille
original. In this embodiment, the braille original is assumed as
having each braille character composed of a matrix like that formed
by a braille typewriter or the like.
[0084] First, two histograms 72 and 73 of the binary image 71 of
the braille original are formed in both the vertical and horizontal
directions. The horizontal histogram 72 is formed simply by
counting the number of dots present on each horizontal line along
the y-coordinate axis, and the vertical histogram 73 is formed
simply by counting the number of dots present on each vertical line
along the x-coordinate axis.
[0085] As shown in FIG. 20A, these histograms are constituted of
several columns regularly divided. If these columns are not
regularly divided, it means that the original placed obliquely was
scanned. In such a case, it is necessary to perform a pre-process
of distortion correction.
[0086] After the histograms are formed, first the vertical
histogram 73 is utilized to determine a width of one character.
With this process, partition lines are drawn for each combination
of two columns of the histogram 73. Similarly, the horizontal
histogram 72 is utilized to draw partition lines for each
combination of three columns. The resultant partition lines are
drawn on an area 74 shown in FIG. 20B. Each rectangle 75 indicated
by hatching represents one braille character.
[0087] By using a reference shown in FIG. 21 stored in the memory
of the controller 13, a pattern in each rectangle of the braille
original is converted into an ordinary character code, through
pattern matching. For this pattern matching, the reference is
enlarged or reduced so as to make it match the size of each braille
character in each rectangle 75 shown in FIG. 20B, and thereafter
the sum of matched points is compared with a proper threshold value
to identify the character code.
[0088] After the character code to be converted is identified, each
braille character in the original 71 is replaced by an image of a
character font, by using fonts stored in the controller 13. This
operation is performed so as to replace each braille character by a
font having a proper size by referring to the size of the fetched
rectangle 75.
[0089] An image constituted of ordinary characters is sent to the
printer 12 and an image is formed on a print sheet to terminate the
above processes. An example of an image after the translation
process is shown in FIG. 22B. In this embodiment, for each braille
character of the original shown in FIG. 22A, a corresponding normal
character is printed at the same position as the braille
character.
[0090] The irregularly raised pattern reading apparatus of this
embodiment or the fifth to eighth embodiments to be later
described, can read a geometrical figure constituted of
three-dimensional lines 161 and having a semi-circular cross
section 162. For example, such three-dimensional lines are used for
forming a map for blind person, with solid lines, dot/solid lines,
dot lines, broken lines, and dot/broken lines.
[0091] With the apparatus, the read three-dimensional lines are
converted into an image as shown in FIG. 29B and printed on a print
sheet. In this case, after an irregularly raised original is read
as a binary image and the controller 13 judges that the read binary
image is not an image of braille letters, the binary image is
directly supplied to the printer 12 without performing a process of
replacing braille characters by character fonts.
[0092] An irregularly raised pattern reading apparatus according to
the fifth embodiment of the invention has the structure shown in
FIG. 23.
[0093] In this embodiment, a number of small switches 102 are
disposed in a matrix shape on a plane 101 of the original cover 12
shown in FIG. 14 on the side in contact with an original.
[0094] In the braille mode, similar to the fourth embodiment, a
braille original 104 is placed with its braille surface being
directed upward. At the raised portion of a braille character, the
switch 102 is depressed against the force of a spring 103, and the
coordinate point of the turned-on switch 102 corresponds to an
on-pixel. In this manner, the braille original can be converted
into a binary image, similar to the fourth embodiment. The process
after the binary image is obtained is similar to the fourth
embodiment. In this manner, a copy of normal characters translated
from braille characters or a copy of an image converted from
three-dimensional lines can be obtained as final outputs.
[0095] In reading a normal original, it is placed with its image
surface downward to read the image information with an optical
scanner under the original glass mount 17. In this case, the spring
103 of each switch 102 functions to press the original.
[0096] According to the fifth embodiment, the structure of a roller
scan as in the fourth embodiment can be omitted, and the whole
surface of an original can be read at once so that a read speed can
be increased. Conversely, the fourth embodiment can omit a number
of conductive wires for interconnecting a number of switches 102 of
the fifth embodiment.
[0097] An irregularly raised pattern reading apparatus according to
the sixth embodiment of the invention has the structure shown in
FIG. 24.
[0098] An original press sheet 112 on the bottom of the original
cover 14 is made of elastic material having some thickness, and a
number of pressure sensors 111 are disposed in a matrix shape on
this original press sheet 112 similar to the switches of the fifth
embodiment.
[0099] A braille original is placed on the original glass mount 114
with its braille surface being directed upward, and is fixed with
the original press sheet 112. At the raised portion of the braille
original, the original press sheet is deformed upward convex, and
the pressure sensor 111 above the upward convex portion is applied
with a stronger pressure than other nearby sensors and a larger
output is obtained.
[0100] According to the sixth embodiment, the higher the raised
portion, the stronger the pressure is applied to the sensor. It is
therefore possible to read a braille original as a multi-value
image converted from multi-value outputs. Since a multi-value image
can be read, the application field of this reading apparatus
becomes broader so that an original of a geometrical figure drawn
with three-dimensional lines representative of several different
heights can be read and changed to an image.
[0101] As shown in FIG. 25, in translating braille characters, an
original read as a multi-value image with the braille reading
apparatus 121 is binarized (Step 122) before fetching each
character, and thereafter operations similar to the fourth
embodiment are performed.
[0102] An irregularly raised pattern reading apparatus of the
seventh embodiment of the invention has the structure shown in
FIGS. 26A and 26B which is an improved version of the original
reading apparatus of the optical type for reading a normal
original.
[0103] Referring to FIG. 26A, mounted on a carriage 132 of an image
pickup sensor 131 are a lens 1 for focussing light on an original
and a lamp 136 for applying light to the original. The sensor 131
is fixed to a sensor board 134 and a signal picked up with the
sensor 131 is supplied to the control unit 13 via a cable 135.
[0104] This lamp 136 can be moved on a rail 137 by an unshown
mechanism between the position near to the sensor 131 and the
position far from the sensor 131 as indicated by a
double-arrow.
[0105] In the normal mode for reading an image original, the lamp
136 is set as near as possible to the sensor 131 as shown in FIG.
26A so that a shade is hard to be produced by a step portion if it
is not so high, the step portion being formed by attaching a sheet
of paper on the original.
[0106] As the mode is switched to the braille mode, the lamp 136 is
moved to the position far from the sensor as shown in FIG. 26B.
Since the light source is remote from the position where the
original is read and becomes approximately horizontal to the
original, a shade 140 is likely to be produced by a step portion
even if it is not so high.
[0107] As shown in FIG. 26B, a gap 139 is formed between the
original glass mount 17 and the braille original. The lens 133
becomes out of focus in the area where the original is lifted, and
therefore the read image becomes slightly black in this area.
However, it does not become too dense because the degree of the
focus shift caused by a braille character is not great. A shadow
region 140 is lifted and is far more black than the region where
light is applied.
[0108] A multi-value image of the read braille original is
subjected simply to a threshold comparison by the control unit 13
so that a binary image having black shadows as shown in FIG. 27B
can be formed.
[0109] This binary image is matched with a braille reference like
that shown in FIG. 21 constituted of shadow patterns so that the
original can be translated in the manner like that illustrated in
FIG. 16.
[0110] An irregularly raised pattern reading apparatus according to
the eighth embodiment of the invention has the structure shown in
FIG. 28 modified from that shown in FIGS. 26A and 26B.
[0111] Two lamps 151 and 152 are fixedly mounted on a carriage 132.
In the normal mode, the lamp 151 near the sensor 131 is turned on
to read an original, and in the braille mode, the lamp 152 remote
from the sensor 131 is turned on to read an original.
[0112] In this embodiment, the lamp transport mechanism can be
omitted so that the mode switching can be performed faster. Reading
braille characters and translating them are quite the same as the
seventh embodiment.
[0113] Many widely different embodiments of the present invention
may be constructed without departing from the spirit and scope of
the present invention. It should be understood that the present
invention is not limited to the specific embodiments described in
the specification, except as defined in the appended claims.
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