1. Field of the Invention
The present invention relates to a pattern overlapping device for overlapping a pattern on a sheet-like medium or in document data to be printed on the sheet-like medium for preventing illegal copying, a pattern overlapping method, a pattern overlapping program, and a storage medium in which the pattern overlapping program is stored.
2. Description of the Related Art
In recent years, because of improvement of performance of image formation techniques, when a copy of a sheet-like bill or a security is made by using a digital color copier, the copy quality is so high that it becomes more and more difficult to distinguish the copied ones from the original ones. For this reason, it is necessary to take measures accordingly, for example, it is supposed to completely prevent copying or to prevent correct copying of the bill, the security, or other special documents.
For example, in a company, even among general documents other than the bills, the securities, or other special documents, there are many confidential documents, copying of which is forbidden from the point of view of preservation of confidentiality. Namely, it is necessary to take measures to completely prevent copying or to prevent correct copying of those confidential documents.
For this purpose, studies have been made extensively to inhibit copying of the above mentioned special documents or the confidential documents.
For example, a technique of distinguishing the bill, the security, or other special documents has been proposed, in which input image data are compared to a pre-registered special mark (pattern data) by means of pattern matching, and when it is found that the special mark exists, it is determined that a document is a special document. For example, Japanese Laid Open Patent Application No. 6-125459 (hereinafter, referred to as “reference 1”) and Japanese Laid Open Patent Application No. 2001-86330 (hereinafter, referred to as “reference 2”) disclose such a technique. Further, when it is determined that a document is a special document, copying of the document is prevented.
Japanese Laid Open Patent Application No. 7-36317 (hereinafter, referred to as “reference 3”) and Japanese Laid Open Patent Application No. 7-87309 (hereinafter, referred to as “reference 4”) disclose a technique of distinguishing a confidential document, copying of which is forbidden, by detecting a mark printed on the confidential document and indicating the confidentiality of the document. This technique makes use of a confidential stamp or mark, which is generally stamped on the confidential document. When it is determined that a document is a confidential document, copying of the document is prohibited.
Japanese Laid Open Patent Application No. 9-164739 (hereinafter, referred to as “reference 5”) and Japanese Laid Open Patent Application No. 2001-197297 (hereinafter, referred to as “reference 6”) disclose a technique of embedding a tint block in an image document to be protected from copying, so as to inhibit illegal copy. This technique is applicable to the image document printed on a piece of paper formed with a tint block pattern on the background of the paper, which pattern has a base area and a message area. The tint block pattern is not noticeable in the image document, and does not influence reading of the image document. However, when the image document embedded with a tint block pattern is copied, for example, the message area of the tint block pattern emerges. For example, in the message area, there is a message of “No Copy”. Seeing this message, it is clear that copying of the document is not allowed, and this imposes psychological restrains on not-allowed copying.
Japanese Laid Open Patent Application No. 2004-274092 (hereinafter, referred to as “reference 7”) discloses a technique of overlapping a pattern (such as a dot pattern) indicating specified information on the surface of a sheet on which an image is to be printed, and when reading the image with an image reader, if the dot pattern is detected, output of the image it prevented.
However, for example, in a device utilizing the technique disclosed in reference 7, which performs control based on detection results of the dot pattern, if the edge of a unit pattern (simply referred to as “pattern” where necessary) of the full pattern (referred to as “a pattern group” where necessary) is not in agreement with the edge of the paper, only a part of the pattern can be detected.
As shown in
In the technique of controlling the output of an image based on detection results of a dot pattern or the like, depending on the starting position of reading the image, probably, the dot pattern is read from a middle position, and thus not the full pattern group but only part of the pattern is read.
However, since it is not determined that pattern detection is completed until a full pattern comes, when a full pattern comes at the beginning, pattern detection can be finished immediately, but when a part of the pattern comes, it is necessary to determine first whether the dot pattern being detected is a full pattern or not, and continue to read the next dot pattern until a full pattern comes. As a result, compared to the case in which a full pattern comes at the beginning, when a part of the pattern comes, additional operations are necessary, and this causes delay of pattern detection. In other words, when a part of the pattern is detected, the timing of control of preventing the output of the image changes depending on the starting position of reading the image. In practice, this time difference is large, and the detection and control operations are delayed.
In addition, when the pattern includes additional information, detection of the pattern is also delayed.
As shown in
A general object of the present invention is to solve one or more of the problems of the related art.
A specific object of the present invention is to provide a pattern overlapping device for overlapping a pattern in a sheet-like medium or document data to be printed on the sheet-like medium, which enables detection of the pattern without delay, a pattern overlapping method, a pattern overlapping program, and a storage medium in which the pattern overlapping program is stored.
According to a first aspect of the present invention, there is provided a pattern overlapping method for overlapping a pattern of a predetermined shape on a sheet-like medium or in document data to be printed on the sheet-like medium, comprising:
an overlapping step of overlapping the pattern at an edge of the sheet-like medium without deficiency of the shape of the pattern.
Preferably, the pattern is used for preventing illegal copy of the sheet-like medium.
Preferably, the pattern includes plural pieces of the same additional information used for preventing illegal copying of the sheet-like medium.
According to a second aspect of the present invention, there is provided a pattern overlapping method for overlapping plural rectangular patterns on a rectangular sheet-like medium or in document data to be printed on the sheet-like medium, comprising the step of:
overlapping the rectangular patterns on the rectangular sheet-like medium with sides of the rectangular patterns to be parallel to sides of the rectangular sheet-like medium, the sides of the rectangular patterns having variable length and heights, the rectangular sheet-like medium having a side A of a length W and a side C of a length of H,
wherein
the step of overlapping includes:
a first overlapping step of overlapping one of the patterns having a side B of a length w and a side D of a length h from an edge of the sheet-like medium for a number of [W/2/w] times, where, the bracket [] is a Gaussian notation, and the expression [W/2/w] represents a maximum integer not greater than (W/2/w),
a second overlapping step of overlapping one of the patterns having the side B of a length (W/2 mod w)×2 and a side D of a length h from a position after the first overlapping step is executed, where, the expression (W/2 mod w) represents the smallest positive remainder of (W/2/w), and
a third overlapping step of overlapping one of the patterns having the side B of a length w and a side D of a length h for a number of [(W/2)/w] times from the position after the second overlapping step is executed.
Preferably, the method further includes a determination step, after the third overlapping step, of determining whether the first overlapping step, the second overlapping step, and the third overlapping step are to be executed from a position lowered by a distance of h from the side A in a direction perpendicular to the side A.
Preferably, after the third overlapping step, when next execution of the first overlapping step, the second overlapping step, and the third overlapping step is the {[(H/2)/h]+1}-th overlapping in a direction parallel to the side C, the length of the side D of the rectangular pattern is set to be 2×(H/2 mod h) in the next execution of the first overlapping step, the second overlapping step, and the third overlapping step.
According to a third aspect of the present invention, there is provided a pattern overlapping method for overlapping a pattern of a predetermined shape on a sheet-like medium or in document data to be printed on the sheet-like medium, said pattern including an additional information portion, said method comprising:
an overlapping step of overlapping the additional information portion at an edge of the sheet-like medium without deficiency of the additional information portion.
Preferably, the pattern is used for preventing illegal copying of the sheet-like medium.
Preferably, the pattern includes plural additional information portions.
According to a fourth aspect of the present invention, there is provided a pattern overlapping method for overlapping plural rectangular patterns on a rectangular sheet-like medium or in document data to be printed on the sheet-like medium, comprising the step of:
overlapping the rectangular patterns on the rectangular sheet-like medium with sides of the rectangular patterns to be parallel to sides of the rectangular sheet-like medium, the sides of the rectangular patterns having variable length and heights, the rectangular sheet-like medium having a side A of a length W and a side C of a length of H,
wherein
the step of overlapping includes:
a first overlapping step of overlapping one of the patterns having a side B of a length w and a side D of a length h from an edge of the sheet-like medium for a number of [W/2/w] times,
a second overlapping step of overlapping one of the patterns having the side B of a length (W/2 mod w) and a side D of a length h from a position after the first overlapping step is executed,
a third overlapping step of overlapping one of the patterns having the side B of a length (W/2−r mod w) and a side D of a length h from a position after the second overlapping step is executed, where r is a constant,
a fourth overlapping step of overlapping one of the patterns having the side B of a length w and a side D of a length h for a number of [((W/2)−r)/w] times from the position after the third overlapping step is executed, and
a fifth overlapping step of overlapping one of the patterns with the side B of a length r and a side D of a length h from the position after the fourth overlapping step is executed.
Preferably, the method further includes a determination step, after the fifth overlapping step, of determining whether the first overlapping step, the second overlapping step, the third overlapping step, the fourth overlapping step, and the fifth overlapping step are to be executed from a position lowered by a distance of h from the side A in a direction perpendicular to the side A.
Preferably, after the fifth overlapping step, when the next execution of the first overlapping step, the second overlapping step, the third overlapping step, the fourth overlapping step, and the fifth overlapping step is the {[(H/2)/h]+1}-th overlapping in a direction parallel to the side C, the length of the side D of the rectangular pattern is set to be 2×(H/2 mod h) in the next execution of the first overlapping step, the second overlapping step, the third overlapping step, the fourth overlapping step, and the fifth overlapping step.
According to a fifth aspect of the present invention, there is provided a program executable in a computer for overlapping plural rectangular patterns on a rectangular sheet-like medium or in document data to be printed on the sheet-like medium, said program driving the computer to execute the step of:
overlapping the rectangular patterns on the rectangular sheet-like medium with sides of the rectangular patterns to be parallel to sides of the rectangular sheet-like medium, the sides of the rectangular patterns having variable length and heights, the rectangular sheet-like medium having a side A of a length W and a side C of a length of H,
wherein
the step of overlapping includes:
a first overlapping step of overlapping one of the patterns having a side B of a length w and a side D of a length h from an edge of the sheet-like medium for a number of [W/2/w] times, a second overlapping step of overlapping one of the patterns having the side B of a length (W/2 mod w)×2 and a side D of a length h from a position after the first overlapping step is executed, and
a third overlapping step of overlapping the pattern having the side B of a length w and a side D of a length h for a number of [(W/2)/w] times from the position after the second overlapping step is executed.
According to a sixth aspect of the present invention, there is provided a storage medium including a program executable in a computer for overlapping plural rectangular patterns on a rectangular sheet-like medium or in document data to be printed on the sheet-like medium, said program driving the computer to execute the step of:
overlapping the rectangular patterns on the rectangular sheet-like medium with sides of the rectangular patterns to be parallel to sides of the rectangular sheet-like medium, the sides of the rectangular patterns having variable length and heights, the rectangular sheet-like medium having a side A of a length W and a side C of a length of H,
wherein
the step of overlapping includes:
a first overlapping step of overlapping one of the patterns having a side B of a length w and a side D of a length h from an edge of the sheet-like medium for a number of [W/2/w] times,
a second overlapping step of overlapping one of the patterns having the side B of a length (W/2 mod w)×2 and a side D of a length h from a position after the first overlapping step is executed, and
a third overlapping step of overlapping the pattern having the side B of a length w and a side D of a length h for a number of [(W/2)/w] times from the position after the second overlapping step is executed.
According to a seventh aspect of the present invention, there is provided a pattern overlapping device for overlapping a pattern of a predetermined shape on a sheet-like medium or in document data to be printed on the sheet-like medium, comprising:
an overlapping unit configured to overlap the pattern at an edge of the sheet-like medium without deficiency of the shape of the pattern.
Preferably, the pattern is used for preventing illegal copying of the sheet-like medium.
Preferably, the pattern includes plural pieces of the same additional information used for preventing illegal copying of the sheet-like medium.
According to an eighth aspect of the present invention, there is provided a pattern overlapping device for overlapping plural rectangular patterns on a rectangular sheet-like medium or in document data to be printed on the sheet-like medium, comprising:
an overlapping unit configured to overlap the rectangular patterns on the rectangular sheet-like medium with sides of the rectangular patterns to be parallel to sides of the rectangular sheet-like medium, the sides of the rectangular patterns having variable length and heights, the rectangular sheet-like medium having a side A of a length W and a side C of a length of H,
wherein
the overlapping unit includes:
a first overlapping unit configured to overlap one of the patterns having a side B of a length w and a side D of a length h from an edge of the sheet-like medium for a number of [W/2/w] times,
a second overlapping unit configured to overlap one of the patterns having the side B of a length (W/2 mod w)×2 and a side D of a length h from a position after the first overlapping step is executed, and
a third overlapping unit configured to overlap one of the patterns having the side B of a length w and a side D of a length h for a number of [(W/2)/w] times from the position after the second overlapping step is executed.
Preferably, the pattern overlapping device further includes a determination unit configured to, after the third overlapping unit finishes overlapping, determine whether the first overlapping unit, the second overlapping unit, and the third overlapping unit are to perform overlapping from a position lowered by a distance of h from the side A in a direction perpendicular to the side A.
Preferably, after the third overlapping unit finishes overlapping, when next overlapping operation of the first overlapping unit, the second overlapping unit, and the third overlapping unit is the {[(H/2)/h]+1}-th overlapping operation in a direction parallel to the side C, the length of the side D of the rectangular pattern is set to be 2×(H/2 mod h) in the overlapping operation of the first overlapping unit, the second overlapping unit, and the third overlapping unit.
According to a ninth aspect of the present invention, there is provided a pattern overlapping device for overlapping a pattern of a predetermined shape on a sheet-like medium or in document data to be printed on the sheet-like medium, said pattern including an additional information portion, the pattern overlapping device comprising:
an overlapping unit configured to overlap the additional information portion at an edge of the sheet-like medium without deficiency of the additional information portion.
Preferably, the pattern is used for preventing illegal copying of the sheet-like medium.
Preferably, the pattern includes plural additional information portions.
According to a 10th aspect of the present invention, there is provided a pattern overlapping device for overlapping plural rectangular patterns on a rectangular sheet-like medium or in document data to be printed on the sheet-like medium, comprising:
an overlapping unit configured to overlap the rectangular patterns on the rectangular sheet-like medium with sides of the rectangular patterns to be parallel to sides of the rectangular sheet-like medium, the sides of the rectangular patterns having variable length and heights, the rectangular sheet-like medium having a side A of a length W and a side C of a length of H,
wherein
the overlapping unit includes:
a first overlapping unit configured to overlap one of the patterns having a side B of a length w and a side D of a length h from an edge of the sheet-like medium for a number of [W/2/w] times,
a second overlapping unit configured to overlap one of the patterns having the side B of a length (W/2 mod w) and a side D of a length h from a position after the first overlapping step is executed,
a third overlapping unit configured to overlap one of the patterns having the side B of a length (W/2−r mod w) and a side D of a length h from a position after the second overlapping step is executed, where r is a constant,
a fourth overlapping unit configured to overlap one of the patterns having the side B of a length w and a side D of a length h for a number of [((W/2)−r)/w] times from the position after the third overlapping step is executed, and
a fifth overlapping unit configured to overlap one of the patterns with the side B of a length r and a side D of a length h from the position after the fourth overlapping step is executed.
Preferably, the pattern overlapping device further includes a determination unit configured to, after the fifth overlapping step finishes overlapping, determine whether the first overlapping unit, the second overlapping unit, the third overlapping unit, the fourth overlapping unit, and the fifth overlapping unit are to perform overlapping operation from a position lowered by a distance of h from the side A in a direction perpendicular to the side A.
Preferably, after the fifth overlapping unit finishes overlapping, when next overlapping operation of the first overlapping unit, the second overlapping unit, the third overlapping unit, the fourth overlapping unit, and the fifth overlapping unit is the {[(H/2)/h]+1}-th overlapping operation in a direction parallel to the side C, the length of the side D of the rectangular pattern is set to be 2×(H/2 mod h) in the next overlapping operation of the first overlapping unit, the second overlapping unit, the third overlapping unit, the fourth overlapping unit, and the fifth overlapping unit.
According to the present invention, it is possible to provide a pattern overlapping device for overlapping a pattern in a sheet-like medium or document data to be printed on the sheet-like medium, which enables detection of the pattern without a delay, and provide a pattern overlapping method, a pattern overlapping program, and a storage medium in which the pattern overlapping program is stored.
These and other objects, features, and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments given with reference to the accompanying drawings.
Below, preferred embodiments of the present invention are explained with reference to the accompanying drawings.
The device shown in
The MFP 10 includes a CPU 11, a memory 12, a HDD (hard disk) 13, an operation panel 14, a scanner 15, a printer 16, a control information unit 17, and a pattern detection unit 18.
The CPU 11 controls operations of the whole MFP 10. The memory 12 stores programs or data. The HDD 13 stores image data. The operation panel 14 is a user interface (I/F). The scanner 15 inputs an image. The printer 16 outputs an image. The control information unit 17 outputs an input image, and performs image processing required for storing the image. The pattern detection unit 18 detects whether a certain pattern exists in the document to be copied, and when it is detected that the pattern exists, the control information unit 17 stops copying the document.
The control information unit 17 corresponds to the overlapping unit, the first overlapping unit, the second overlapping unit, the third overlapping unit, the fourth overlapping unit, the fifth overlapping unit, and the determination unit in claims.
In the above-mentioned device, a pattern can be overlapped on a sheet by the MFP 10 when the MFP 10 outputs an image on the sheet, or the pattern can be overlapped on document data by a driver of the MFP 10 in the PC 22 or WS 21, which document data are to be printed on the sheet by the MFP 10.
For example, the pattern includes a large number of small dots arranged in a matrix manner, and the pattern is overlapped to prevent illegal copying of the sheet. When the pattern detection unit 18 detects that the pattern exists in the sheet or in the document data, for example, the MFP 10 outputs a black sheet to prevent illegal copying. Of course, the thus overlapped pattern can also be used for purposes other than illegal copy prevention.
Next, the pattern overlapping method is explained.
As shown in
In contrast, rectangular areas 41 and 42 have different heights or widths from the rectangular pattern 40, and compared to the shape of the rectangular pattern 40, the rectangular areas 41 and 42 are printed on the paper 30 with shape deficiencies. Below, a pattern with a shape deficiency is referred to as “an irregular pattern”, and a pattern without a shape deficiency is referred to as “a regular pattern”.
It should be noted that each unit pattern is illustrated to be a blank rectangle, but actually a large number of dots are arranged in the rectangle.
As shown in
Next, the operation of overlapping patterns on the paper 30 is described with reference to the flowchart in
The operations shown in the flowchart in
In step S101, the size of the paper is acquired. For example, the size of the paper 30 may be specific values such as a height of H and a width of W, as shown in
In step S102, from the left edge of the paper 30, the regular pattern is overlapped for a number of [(W/2)/w] times. As is known, the bracket [] is a Gaussian notation, representing a maximum integer not greater than (W/2)/w. That is, the regular patterns are overlapped in the left half portion of the paper 30 up to a position near the vertical center line of the paper 30.
In step S103, at the position when the pattern overlapping in step S102 is completed, a pattern having a length equaling (W/2 mod w)×2 is overlapped. As known, (A mod B) represents the smallest positive remainder of A/B. In other words, in this step, as shown in
In step S104, at the position when the pattern overlapping in step S103 is completed, the regular pattern is overlapped for a number of [(W/2)/w] times. That is, the regular patterns are overlapped in the right half portion of the paper 30 from a position near the vertical center line of the paper 30.
After step S102 through step S104 are executed, one row of patterns (that is, in the horizontal direction) is printed.
In step S105, it is determined whether the next row of the patterns is the {[(H/2)/h]+1}-th row in the vertical direction. That is, it is determined whether the next row is close to the center line in the vertical direction. If the next row is close to the center line, in the next row, the irregular pattern 42 in
If the next row is the {[(H/2)/h]+1}-th row in the vertical direction, the routine proceeds to step S106. Otherwise, the routine proceeds to step S107.
In step S106, the height of the pattern (that is, length in the vertical direction) overlapped in the next row is set be (H/2 mod h)×2. Then, the routine returns to step S102.
In step S107, it is determined whether overlapping of the pattern over the full size of the paper 30 is completed. If overlapping of the pattern over the full size of the paper is completed, the routine is finished. Otherwise, the routine returns to step S102 to repeat the steps from S102 to S107.
The above-described steps S102, S103, S104 correspond to the first overlapping step, the second overlapping step, and the third overlapping step, respectively, in claims. The step S107 corresponds to the determination step in claims.
Next, a pattern including additional information is explained. For example, the additional information directs the MFP 10 not to output a black sheet but a sheet of other colors, or other information indicating types of illegal copy prevention. For example, when the MFP 10 performs authentication by using an ID card, if it is identified that the person who is making copies is a person allowed to do that, the additional information directs the MFP 10 to allow the person to make copies.
As shown in
Because of the presence of plural pieces of the same additional information, no matter whether the pattern 50 is read in either the direction as shown by an arrow 55 or the direction as shown by an arrow 56 in
In order to enable reading in different directions, center lines A and B of the pattern in
In the example shown in
Four patterns 60, 61, 62, and 63 are shown in
In the pattern 60, the rectangular divisions 70 include additional information; in the pattern 61, the rectangular divisions 71 include additional information; in the pattern 62, the rectangular divisions 72 include additional information; and in the pattern 63, the rectangular divisions 73 include additional information.
When detecting the patterns 60, 61, 62, and 63, for example, by a combination of divisions including three dots and divisions including two dots, different operations are performed according to the different manner of arranging the two dots. For example, in the pattern 60, the MFP 10 rings to inform people in the surrounding area of the illegal copying. In the pattern 61, the MFP 10 sends an electronic mail to a manager to make a record of the illegal copying. In the pattern 62, the MFP 10 lights a lamp of a manager to inform people in the surrounding area of the illegal copying. In the pattern 63, the MFP 10 takes a log to record the illegal copying. There may be other ways to use the additional information in the pattern.
Next, the method of overlapping the pattern including the additional information is explained.
As shown in
In contrast, rectangular areas 81 and 83 have different heights or widths from the rectangular pattern 82. The rectangular areas 81 and 83 are printed near a center line 85 (dashed line). Compared to the shape of the rectangular pattern 82, the rectangular areas 81 and 83 are printed on the paper 80 with shape deficiencies. Similar to the definition in
When making a copy of the paper 80, because it is from one edge that the paper 80 is read, with the regular patterns being printed at the edges of the paper 80, as shown in
In
Next, the operation of overlapping patterns on the paper 80 is described with reference to the flowchart in
The operations shown in the flowchart in
In step S201, the size of the paper is acquired. For example, the size of the paper 80 may be specific values such as a height of H and a width of W, as shown in
In step S202, from the left edge of the paper 80, the regular pattern is overlapped for a number of [(W/2)/w] times. As known, the bracket [] is a Gaussian notation, representing a maximum integer not greater than (W/2)/w. That is, the regular patterns are overlapped in the left half of the paper 80 up to a position near the center line 85 of the paper 80.
In step S203, at the position when the pattern overlapping in step S202 is completed, a pattern having a length equaling (W/2 mod w) is overlapped. As known, (A mod B) represents the remainder of A/B. In other words, in this step, as shown in
In step S204, at the position when the pattern overlapping in step S203 is completed, a pattern having a length equaling ((W/2)−r mod w) is overlapped. That is, in this step, as shown in
In step S205, at the position when the pattern overlapping in step S204 is completed, the regular pattern is overlapped for a number of [((W/2)−r)/w] times. That is, the regular patterns are printed in the right half portion of the paper 80.
In step S206, at the position when the pattern overlapping in step S204 is completed, a pattern having a length equaling r is printed. That is, in this step, an additional information area is printed.
After step S202 through step S206 are executed, one row of patterns (that is, in the horizontal direction) is printed.
In step S207, it is determined whether the next row of the patterns is the {[(H/2)/h]+1}-th row in the vertical direction. That is, it is determined whether the next row is close to the center line in the vertical direction. If the next row is close to the center line, irregular patterns should be overlapped in the next row.
If the next row is the {[(H/2)/h]+1}-th row in the vertical direction, the routine proceeds to step S208. Otherwise, the routine proceeds to step S209.
In step S208, the height of the pattern (that is, length in the vertical direction) overlapped in the next row is set be (H/2 mod h)×2. Then, the routine returns to step S202.
In step S209, it is determined whether printing of the pattern over the full size of the paper 80 is completed. If overlapping of the pattern over the full size of the paper is completed, the routine is finished. Otherwise, the routine returns to step S202 to repeat the steps from S202 to S209.
The above-described steps S202, S203, S204, S205, S206 correspond to the first overlapping step, the second overlapping step, the third overlapping step, the fourth overlapping step, and the fifth overlapping step in claims. The step S209 corresponds to the determination step in claims.
Due to the operations shown in the flowchart in
In
In the above descriptions, in order that detection delay does not occur, patterns are printed at edges of the paper without shape deficiencies, or the additional information areas are added. For this purpose, irregular patterns are primarily printed at center portions of the paper, which are far from the edges of the paper.
It should be noted that the present embodiment is not limited to this situation. Specifically, the irregular patterns may be printed at various positions other than the center portions of the paper. When the irregular patterns are printed at a localized area, non-uniformity may be caused by the irregular patterns, or the dots are not uniformly distributed. When the irregular patterns are printed at various positions, such kind of non-uniformity can be reduced.
A program executing the flowchart in
While the present invention is described above with reference to specific embodiments chosen for purpose of illustration, it should be apparent that the invention is not limited to these embodiments, but numerous modifications could be made thereto by those skilled in the art without departing from the basic concept and scope of the invention.
This patent application is based on Japanese Priority Patent Application No. 2005-171061 filed on Jun. 10, 2005, and the entire contents of which are hereby incorporated by reference.
Number | Date | Country | Kind |
---|---|---|---|
2005-171061 | Jun 2005 | JP | national |