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Description  |
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FIELD OF THE INVENTION
The present invention relates to image processing apparatuses, such as copying machines, scanners, facsimiles, and printers, which are capable of automatically joining images, which have been read in a divided manner, and forming the joined image
on a recording medium of a desired size.
BACKGROUND OF THE INVENTION
In order to combine a plurality of images together and to record the combined image on one sheet of paper, an information recording apparatus, such as disclosed in Japanese Examined Patent Publication No. 33752/1981 (Tokukoushou 56-33752), is
employed. In this apparatus, image data for each page is stored as each independent data. For example, if image data of 4 pages of A-4 size are respectively stored as independent data, the information recording apparatus is capable of reducing the
stored image data respectively and combining them together so as to form the combined image on one sheet of paper of A-4 size.
Here, in the case of applying the above-mentioned operation to an original document of a large size which cannot be read through one complete scanning, the image of the original document is read in a divided manner. These divided images are
stored as divided image data including of a plurality of pages. However, in the above-mentioned apparatus, since the image data are stored as individual data for respective pages, there is no correlation between those individual data for respective
pages. For this reason, even if the divided image data are reduced for the respective pages, and combined together, the divided images cannot be joined together into the original form.
Therefore, in the case of copying an original document having a size larger than, for example, the document platen on one sheet of paper of a desired size, the following method is used:
(1) An original document is divided into a plurality of regions, and those regions are respectively reduced and copied to form divided original documents;
(2) The divided original documents are trimmed and pasted to form one sheet of original document;
(3) The original document thus joined together is again copied.
However, in such a method including the above (1) through (3), troublesome and time consuming tasks are required in positioning and pasting the divided original documents manually, and in calculating a reduction rate in accordance with the size
of copy sheet whereon a complete copied image is formed. Further, even if the reduction rate is set uniformly in obtaining the divided original documents, slight errors are inevitable in the reduction rates for the divided original documents.
Therefore, offsets might be produced at the joints when those divided original documents are joined together.
Meanwhile, Japanese Laid-Open Patent Publication No. 331567/1992 (Tokukaihei 4-331567) has disclosed a digital image forming apparatus wherein in the case of copying an original document that is larger than the copiable size, a plurality of image
data that have been individually read are combined and compiled, and are reduced into a copiable size.
In this apparatus, if the copying operation is performed on an original document that is, for example, twice as large as the readable size, the original document is divided into two equal portions, and the portions are successively read. Then
the image data thus read are reduced, if necessary. In this case, upon reading the image data, the original document to be read later is placed on the document platen in a state where it is rotated by 180 degrees with respect to the original document
that was read previously. Then, the image data that was read firstly is rotated by 90 degrees, while the image data that was read secondly is rotated by 90 degrees in the direction opposite to the first rotation, and both of the image data are combined
together. Thus, a combined image is formed on one sheet of paper. Therefore, with such a digital image forming apparatus, the aforementioned troublesome and time consuming tasks are eliminated, and even in the case of copying an original document
larger than the size of the document platen, a copied image is formed on one sheet of paper of a desired size.
However, in such an digital image forming apparatus, since the image data are merely reduced, and merely rotated in the predetermined directions, offsets might be produced at the joints in a combined image, thereby causing an adverse effect on
picture quality. Further, in the case where divided original documents of an image come up to a number of pages, sufficient attention should be paid to the orientations of the original documents or to other factors when they are placed on the document
platen. This raises a problem related to low efficiency in operation.
SUMMARY OF THE INVENTION
It is the first objective of the present invention to provide an image processing apparatus which is capable of joining images that have been read in a divided manner accurately, in a short time, without causing any adverse effects on the
efficiency of operation.
It is the second objective of the present invention to provide an image processing apparatus which is capable of reducing the amount of information by which a joining operation is performed.
In order to achieve the first objective, the image processing apparatus of the present invention comprises:
(1) an input means for reading an image of an original document;
(2) a storage means for storing a plurality of partial images as respective partial document data, the partial images having been read by the input means in a divided manner; and
(3) a joint-portion processing means for recognizing reference data in response to an output of the input means, the reference data providing a key by which joints of the partial document data that have been stored in the storage means are
retrieved, for recognizing the joints using the recognized reference data as a key, and for positioning the respective partial document data in accordance with the recognized joints.
With the above arrangement, the joint-portion processing means recognizes reference data in response to the output of the input means, and further recognizes the joints of the partial document data that have been stored in the storage means by
using the reference data as a key. Then, the joint-portion processing means positions the partial document data in accordance with the recognized joints, and joins those partial document data, thereby forming document data that correspond to the image
of the original document.
More specifically, such reference data, which provide a key for detecting the joints, include: for example, specific partial document data that are predeterminately specified; partial document data that are first stored in the storage means; data
indicating a layout of the partial document data that are set in accordance with the storage sequence of the partial document data and a divided condition of the image; marks that are added to the partial document data so as to indicate the joints; and
numbers that are added to the partial document data so as to determine the layout of the partial document data.
Therefore, in the case of using an original document that has to be read by the input means in a divided manner due to, for example, its large size or other reasons, troublesome and time consuming tasks such as trimming and pasting the divided
images are eliminated. This improves efficiency of the operation. Further, joints are recognized from the partial document data using these reference data as a key, and the joining operation is carried out in accordance with the joints. Therefore,
even in the case where an image is divided into a number of portions, the joining operation of the divided images is executed accurately in a short time.
Moreover, a variable magnification means for variably magnifying the joined document data into a desired size may be added to the above arrangement. Thus, the joined image is readily reduced and formed on a recording medium of a desired size
without the necessity of time consuming calculations on reduction rate.
Also, the image processing apparatus of the present invention is provided with at least the following means in order to achieve the first objective:
(1) an input means for reading an image of an original document;
(2) a storage means for storing a plurality of partial images as respective partial document data, the partial images having been read by the input means in a divided manner; and
(3) a joint-portion processing means for obtaining specific image data containing features from the partial document data stored in the storage means by retrieving the partial document data stored in the storage means, and for selecting two
partial document data in the order of their increasing number on the specific image data, comparing the specific image data each other, recognizing joints at which the specific image data coincide with each other, and positioning the respective partial
document data in accordance with the recognized joints.
With the above arrangement, the joint-portion processing means obtains the specific image data containing features from the partial document data by retrieving the partial document data stored in the storage means, and recognizes joints of the
partial document data in the order of their increasing number on the specific image data obtained. In other words, the two partial document data, which have virtually the same amount of specific image data, have a high probability of coincident specific
image data. Therefore, by performing the recognition of specific image data in accordance with the above order, it becomes easier to find sides at which their specific image data coincide with each other, even in the case where the sides contain few
specific image data and it would be difficult to find joints from the sides.
Therefore, with the arrangement where the sequence of the joining operation is set in accordance with the amount of specific image data containing features, the joints are recognized in a short time and the layout of the partial document data is
easily determined without paying any particular attention to factors such as the sequence of inputting documents and the orientations of the documents upon reading. This occurs in the case of performing the joining operation on, for example, a number of
original documents or on original documents having complicated images. As a result, it becomes possible to carry out the joining operation accurately and quickly, to improve the efficiency of operation in joining images, and to prevent offsets that
would occur at the joints. This ensures high quality in the images.
Also, the image processing apparatus of the present invention is provided with at least the following means in order to achieve the first objective:
(1) an input means for reading an image of an original document;
(2) a storage means for storing a plurality of partial images as respective partial document data, the partial images having been read by the input means in a divided manner;
(3) a document-color recognition means for forming color data corresponding to the respective partial document data by recognizing the colors of the images read by the input means; and
(4) a joint-portion processing means for recognizing joints located between the partial document data stored in the storage means by retrieving the pattern of colors in the partial document data while comparing the color data formed in the
document-color recognition means with the partial document data stored in the storage means, and for positioning the respective partial document data in accordance with the recognized joints.
With the above arrangement, the colors of the images read by the input means are recognized by the document-color recognition means. Further, the joint-portion processing means recognizes the joints by performing the retrieving operation while
comparing the color data formed in the document-color recognition means with the respective partial document data, thereby joining the partial document data together.
Therefore, even in the case of performing the joining operation on, for example, a number of original documents or on original documents having complicated images, a plurality of partial images are joined together accurately and quickly without
paying any particular attention to factors such as the sequence of inputting documents and the orientations of the documents upon reading. Thus, it becomes possible to improve the efficiency of the operation and to enhance the quality of the images.
Moreover, in order to achieve the first and second objectives, the image processing apparatus of the present invention is provided with at least the following means:
(1) an input means for reading an image of an original document;
(2) a storage means for storing a plurality of partial images as respective partial document data, the partial images having been read by the input means in a divided manner; and
(3) a joint-portion processing means for recognizing joints located between the partial document data stored .in the storage means and for extracting image data that lie in a direction orthogonal to the joints of the partial document data and
positioning the respective partial document data in accordance with the image data that lie in a direction orthogonal to the joints.
With the above arrangement, the joint-portion processing means recognizes the joints from the partial document data stored in the storage means, and positions the respective partial document data. In performing this positioning, the image data
that lie in a direction orthogonal to the joints of the partial document data are extracted, and the positioning is performed so that the image data that lie in the orthogonal direction coincide with each other. This makes the change of extracted image
data clearer in the positioning as compared to the case of extracting image data that have slant angles with respect to the respective joints and performing the positioning by shifting the extracted image data in a parallel or perpendicular direction.
Therefore, since the positioning of the partial document data is carried out more effectively by the use of less image data, it becomes possible to reduce the amount of information, and to shorten the time of the joining operation. Thus, the
original documents read in a divided manner are joined together more accurately without causing any adverse effects on the efficiency of the operation.
Also, in order to achieve the first and second objectives, the image processing apparatus of the present invention is provided with at least the following means:
(1) an input means for reading an image of an original document;
(2) a storage means for storing a plurality of partial images as respective partial document data, the partial images having been read by the input means in a divided manner;
(3) a black-document discrimination means for discriminating whether the partial document data in question stored in the storage means are mono-color document data or color document data; and
(4) a joint-portion processing means for recognizing joints located between the partial document data stored in the storage means and for converting the color document data that have been discriminated by the black-document discriminating means
into mono-color document data and positioning the respective partial document data in accordance with the converted mono-color document data.
With the above arrangement, the joint-portion processing means recognizes the joints from the partial document data stored in the storage means, and positions the respective partial document data so that the respective images are smoothly joined
together. In performing the positioning of the partial document data, a discrimination is first made as to whether the partial document data in question stored in the storage means are mono-color document data or color document data. Then, if the
discrimination is made as color document data, the color document data are converted into mono-color document data.
Therefore, since the positioning of the partial document data is carried out based on only the mono-color document data, it becomes possible to reduce the amount of information, and to shorten the time of the joining operation, as compared to the
case where a decision is made for each of the colors, red, green and blue, in positioning the color document data.
Therefore, since the positioning of the partial document data is carried out more effectively by the use of less image data, it becomes possible to reduce the amount of information, and to shorten the time of the joining operation. Thus, the
original documents read in a divided manner are joined together more accurately without causing any adverse effects on the efficiency of the operation.
Also, in order to achieve the first and second objectives, the image processing apparatus of the present invention is provided with at least the following means:
(1) an input means for reading an image of an original document;
(2) a storage means for storing a plurality of partial images as respective partial document data, the partial images having been read by the input means in a divided manner;
(3) a joint-portion processing means for recognizing joints located between the partial document data stored in the storage means, and for enhancing the image data so that the outlines of images located in the proximity of the joints are made
distinct, and for positioning the respective partial document data in accordance with the enhanced image data.
With the above arrangement, the joint-portion processing means recognizes the joints from the partial document data stored in the storage means, and positions the respective partial document data so that the respective images are smoothly Joined
together. Here, in the case of using original documents of half-tone such as photographs wherein outlines of images are in a diffused state, images obtained in the proximity of the joints tend to be obscure upon positioning the partial document data.
In order to solve this problem, an image enhancing operation, such as formation of outline data by emphasizing the density of edges or by means of a differential processing, is performed. This eliminates the diffused state of the images, and
makes the outlines of the images clearer. Thus, it becomes possible to perform the positioning of the partial document data more easily as well as more accurately based on the enhanced image data.
Therefore, since the positioning of the partial document data is carried out more effectively by the use of less image data, it becomes possible to reduce the amount of information, and to shorten the time of the joining operation. Thus, the
original documents read in a divided manner are joined together more accurately without causing any adverse effects on the efficiency of the operation.
For a fuller understanding of the nature and advantages of the invention, reference should be made to the ensuing detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a construction of an image processing system that is installed in a digital copying machine in one embodiment of the present invention.
FIG. 2 is an explanatory drawing that schematically shows the construction of the digital copying machine.
FIG. 3 is a flow chart showing the sequence of processes that are carried out during a joining operation on partial document data in the digital copying machine.
FIG. 4 is a schematic drawing showing partial document data that are stored in an image memory in the image processing system.
FIG. 5(a) is a schematic drawing which shows retrieving regions in the partial document data; FIG. 5(b) is a schematic drawing which explains the positioning of the partial document data; and FIG. 5(c) is a plan view showing a copied image that
is obtained by joining the partial document data together.
FIG. 6 is a flow chart showing the sequence of processes that are carried out during a joining operation on partial document data in the digital copying machine of another embodiment of the present invention.
FIG. 7(a) is a schematic drawing which shows a layout of the inputted partial document data in the case of performing the operation shown in the flow chart of FIG. 6; FIG. 7(b) is a schematic drawing which shows the sequence of the joining
operation; and FIG. 7(c) is a plan view showing a copied image that is obtained by joining the partial document data together.
FIG. 8 is a flow chart showing the sequence of processes that are carried out during a joining operation on partial document data in the digital copying machine of still another embodiment of the present invention.
FIG. 9(a) is a schematic drawing which shows one example of the inputted partial document data in the case of performing the operation shown in the flow chart of FIG. 8; FIG. 9(b) is a schematic drawing which explains the positioning of the
partial document data; and FIG. 9(c) is a plan view showing a copied image that is obtained by joining the partial document data together.
FIG. 10 is a schematic drawing which shows one example of the partial document data whereon a plurality of marks are put, in the case of performing the operation shown in the flow chart of FIG. 8.
FIG. 11 is a flow chart showing the sequence of processes that are carried out during a joining operation on partial document data in the digital copying machine of still another embodiment of the present invention.
FIG. 12 is a schematic drawing which shows original documents on which the operation shown in the flow chart of FIG. 11 is carried out.
FIG. 13 is a schematic drawing which shows a layout of documents that is determined based on numbers that are put on the documents of FIG. 12.
FIG. 14(a) is a schematic drawing which shows retrieving regions in the partial document data in the case of processing one portion of the original documents shown in FIG. 12; FIG. 14(b) is a schematic drawing which explains the positioning of
the partial document data; and FIG. 14(c) is a plan view showing a copied image that is obtained by joining the partial document data together.
FIG. 15 is a flow chart showing the sequence of processes that are carried out during a joining operation on partial document data in the digital copying machine of still another embodiment of the present invention.
FIG. 16 is a flow chart showing the sequence of processes that are carried out when the features of the original documents are extracted in the flow chart of FIG. 15.
FIG. 17 is a schematic drawing which shows a layout of the partial document data in an image memory of the digital copying machine.
FIG. 18 is a schematic drawing which shows retrieving regions of the partial document data that are stored in the image memory.
FIG. 19 is a flow chart showing the sequence of processes that are carried out during a decision on coincidence or non-coincidence of the document data in the flow chart of FIG. 15
FIG. 20 is a flow chart showing the sequence of processes that are carried out during a judgement as to the completion of all the data processing in the flow chart of FIG. 15.
FIG. 21 is a schematic drawing which shows a layout of four images on which the operation shown in the flow chart of FIG. 15 is performed.
FIG. 22 is a flow chart showing the sequence of processes that are carried out during a compensation for loss of data in the flow chart of FIG. 15.
FIG. 23 is a schematic drawing which shows the partial document data in question on which the compensation for loss of data is carried out.
FIG. 24 is a flow chart showing the sequence of processes that are carried out during a compensation for loss of data in the flow chart of FIG. 15.
FIG. 25 is a flow chart showing the sequence of processes that are carried out during a judgement as to the completion of all the data processing in the flow chart of FIG. 15.
FIGS. 26(a) through 26(f) are plan views showing original documents on which the joining operation is carried out.
FIG. 27 is a schematic drawing which explains the positioning process of the partial document data in the joining operation.
FIG. 28 is a plan view showing a copied image that is obtained by joining the partial document data together.
FIG. 29 is a block diagram showing a construction of an image processing system that is installed in a digital copying machine in still another embodiment of the present invention.
FIGS. 30(a) and 30(b) are plan views showing original documents on which the joining operation is carried out in the digital copying machine.
FIG. 31 is a schematic drawing which explains the positioning process of the partial document data in the joining operation.
FIG. 32 is a plan view showing a copied image that is obtained by Joining the partial document data together.
FIG. 33 is a block diagram showing a construction of an image processing system that is installed in a digital copying machine in still another embodiment of the present invention.
FIG. 34(a) is a schematic drawing which shows partial document data stored in the image memory of the image processing system; FIG. 34(b) is a schematic drawing which shows a state wherein positioning is made by extracting image data that lie in
a direction orthogonal to the joints; FIG. 34(c) is a schematic drawing which shows the image data after the positioning has been completed; and FIG. 34(d) is a schematic drawing which shows a reduced state of the document data that have been joined
together.
FIG. 35 is a flow chart showing the sequence of processes that are carried out during a data extraction on each side of the partial document data in the operation shown in the flow chart of FIG. 15.
FIG. 36(a) is a schematic drawing which shows a state wherein positioning is made on the partial document data by the use of image data that lie in a direction orthogonal to the joints; and FIG. 36(b) is a schematic drawing which shows a state
wherein positioning is made by the use of image data that have a slant angle with respect to the joints.
FIG. 37 is a block diagram showing a construction of an image processing system that is installed in a digital copying machine in still another embodiment of the present invention.
FIG. 38(a) is a schematic drawing which explains a feature-extracting process by the use of color document data; and FIG. 38(b) is a schematic drawing which explains a feature-extracting process by the use of mono-color document data.
FIG. 39 is a block diagram showing a construction of an image processing system that is installed in a digital copying machine in still another embodiment of the present invention.
FIG. 40(a) is a graph which shows the change in density on the edges of partial document data before the application of an image-enhancing process; FIG. 40(b) is a graph which shows the change in density on the edges of the partial document data
after the image-enhancing process has been made by highlighting the edges; and FIG. 40(c) is a graph which shows the change in density on the edges of the partial document data after the image-enhancing process has been made by means of a differential
processing.
FIG. 41(a) is a schematic drawing which explains the change in density on partial document data as well as the positional variation on the image in relation to the density before the application of an image-enhancing process; FIG. 41(b) is a
schematic drawing which explains the change in density on the partial document data as well as the positional variation on the image in relation to the density after the image-enhancing process has been made by highlighting the edges; and FIG. 41(c) is a
schematic drawing which explains the change in density on the partial document data as well as the positional variation of the image in relation to the density after the image-enhancing process has been made by means of the differential processing.
FIG. 42 is a schematic drawing which shows a formation of outline data by applying the image-enhancing process to the document data by means of the differential processing.
DESCRIPTION OF THE EMBODIMENTS
EMBODIMENT 1
Referring to FIGS. 1 through 5, the following description will discuss one embodiment of the present invention.
As illustrated in FIG. 2, a digital copying machine, which is installed in an image processing apparatus in accordance with the present embodiment, is provided with a document platen 27 made of a hard glass plate, etc. that is installed on the
upper surface of a copying machine main body 26. Below the document platen 27 is disposed a scanner unit (input means) 22. The scanner unit 22 is constituted of: a lamp unit 1; mirrors 2, 3 and 4; a lens unit 5; and a CCD (Charge Coupled Device) sensor
6. A reflected light beam, which is obtained by irradiating a document (not shown) placed on the document platen 27 by the lamp unit 1, is directed to the light-receiving face of the CCD sensor 6 through the mirrors 2, 3 and 4 and the lens unit 5, and
detected therein as electric signals.
A laser driver unit 7, which has a semiconductor laser, a polygon mirror and an f-.theta. lens, is installed below the scanner unit 22. Image data of the document, which are detected by the CCD sensor 6 as the electric signals, are temporarily
stored in an image memory (storage means) 43 installed in the image processing apparatus (see FIG. 1), which will be described later. After having been subject to predetermined processing in the image processing apparatus, the image data are sent to the
laser driver unit 7. The laser driver unit 7 projects a laser beam from the semiconductor laser in response to document data inputted thereto. The laser beam is diffracted by the polygon mirror in a constant angular velocity, and the laser beam that
has been subjected to the diffraction in the constant angular velocity is corrected by the f-.theta. lens so that it is further diffracted in a constant angular velocity on a photoreceptor drum 10.
A laser beam released from the laser driver unit 7 is reflected by the mirrors 8 and 9 that are disposed in the light path, and projected onto the photoreceptor drum 10, thereby forming an electrostatic latent image on the photoreceptor drum 10.
The photoreceptor drum 10 is capable of rotating in the direction of arrow A as shown in FIG. 2. On the periphery of the photoreceptor drum 10, are disposed a charger 16 for charging the photoreceptor drum 10 so as to impart a predetermined voltage to
its surface prior to an exposure executed by laser driver unit 7. Further, from the charger 16 along the rotation direction of the photoreceptor drum 10, are installed in the following order: a developing device 28, a transferring belt 17, a cleaning
device 21, an electrostatic eliminating lamp 15, etc.
The developing device 28 includes a black developer vessel 11, a yellow developer vessel 12, a magenta developer vessel 13, and cyan developer vessel 14, and those developer vessels 11 through 14 respectively house toners having corresponding
colors. The developing device 28 supplies toner onto the electrostatic latent image on the photoreceptor drum 10 such that a toner image is formed thereon.
The transferring belt 17, which is provided in the form of an endless belt, is installed so as to move in the direction of arrow B in the drawing, and one portion of the transferring belt 17 is pressed against the photoreceptor drum 10 such that
the toner image on the photoreceptor drum 10 is transferred thereonto. After the tone image has been transferred, the residual toner on the photoreceptor drum 10 is removed therefrom by the cleaning device 21. Further, prior to the next charge, the
residual electric potential on the photoreceptor drum 10 is eliminated by the electrostatic eliminating lamp 15.
On the paper-feeding side with respect to the transferring belt 17, are installed a resist roller 19, a feeding cassette 20, and a feeding tray 23. In the proximity of the feeding cassette 20 and the feeding tray 23, are installed a feeding
roller 24, a transporting roller 25, etc. Copy sheets stored inside the feeding cassette 20 or on the feeding tray 23 are supplied onto the transferring belt 17 at predetermined intervals by a resist roller 19.
Below the transferring belt 17, is installed a transferring roller 18 which presses a copy sheet sent thereto from the resist roller 19 against the transferring belt 17, and allows the toner image on the transferring belt 17 to be transferred
onto the copy sheet.
On the paper-discharging side with respect to the transferring belt 17, are installed a conveyer belt 30, a fixing device 31 and a discharge roller 32. A copy sheet whereon the toner image has been transferred is transported to the fixing device
31 by the conveyer belt 30, and the toner image is fused onto the copy sheet by heat. The copy sheet whereon the toner image has been fused by heat is discharged outside the copying machine main body 26 by a discharge roller 32.
In the above arrangement, a color-copy (3 color copy) operation is carried out in the following sequence. First, the charger 16 uniformly charges the surface of the photoreceptor drum 10, and the scanner unit 22 executes the first scanning. The
document data detected by the CCD sensor 6 are processed in the image processing section, and are released from the laser driver unit 7 as a laser beam representative of yellow data. The surface of the photoreceptor drum 10 is exposed by the laser beam,
and an electrostatic latent image for yellow-use is formed on the exposed portion of the photoreceptor drum 10. Then, yellow toner is supplied to the electrostatic latent image within the image region from the yellow developer vessel 12, and a yellow
toner image is thus formed.
Next, the yellow toner image is transferred onto the transferring belt 17 that is pressed against the photoreceptor drum 10. At this time, although some toner that has not been consumed in the transferring process remains on the surface of the
photoreceptor drum 10, the residual toner is scraped off by the cleaning device 21. Moreover, the electrostatic eliminating lamp 15 eliminates the residual charge on the surface of the photoreceptor drum 10.
After completion of the above processes, the charger 16 again charges the surface of the photoreceptor drum 10 uniformly, and the scanner unit 22 executes the second scanning. The document data are processed in the image processing section, and
are released as a laser beam representative of magenta data. The surface of the photoreceptor drum 10 is exposed by the laser beam, and an electrostatic latent image for magenta-use is formed on the exposed portion of the photoreceptor drum 10. Then,
magenta toner is supplied to the electrostatic latent image from the magenta developer vessel 13, and a magenta toner image is thus formed. Thereafter, this toner image is transferred onto the transferring belt 17 so as to be superimposed on the former
yellow toner image. After the cleaning device 21 and the electrostatic eliminating lamp 15 have carried out the same processes as described earlier, the charger 16 again charges the surface of the photoreceptor drum 10 uniformly.
Then, the scanner unit 22 executes the third scanning, and an electrostatic latent image for cyan-use is formed by exposing the photoreceptor drum 10 with a laser beam representative of cyan data. Then, cyan toner is supplied to the
electrostatic latent image from the cyan developer vessel 14, and a cyan toner image is thus formed. Thereafter, this cyan toner image is transferred onto the transferring belt 17 so as to be finally superimposed on the former toner images.
A complete toner image on the transferring belt 17, which has been formed by superimposing three toner images, is transferred onto a copy sheet, and the complete toner image is fused onto the copy sheet by heat. Thereafter the | | |
