JP2002086876A - Multicolor printing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize easy judgment of a positional shifting between images without requiring skill and easy and quick execution of the controlling work of the positions of images. SOLUTION: By a plate making means, register marks M1, M2 and M3 each for controlling the position of a printing image are made respectively at the same position of a master of every color. Thus, on a paper P, on which printings are doubled, the register marks M1, M2 and M3 are printed, resulting in allowing to easily confirm and judge the positional shifting between respective images.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor printing apparatus such as a stencil printing apparatus having a plurality of printing drums and capable of performing multicolor printing in one pass (one sheet conveyance).

[0002]

2. Description of the Related Art For example, in a one-pass type multicolor stencil printing apparatus, a plurality of printing drums having different printing colors are arranged around one printing pressure cylinder, and the paper fed by a paper feeding unit is printed. The multi-color printing is performed by nipping and transporting with a clamper. In addition, Japanese Patent Application Laid-Open
As disclosed in Japanese Patent Publication No. 315601, there is also known a method in which a plurality of printing drums are juxtaposed on a horizontal plane, and a sheet is conveyed linearly to perform multicolor overprinting.

In such a multicolor printing apparatus, it is inevitable that an image position is shifted between printing units (between printing drums). It has a position adjustment mechanism, and has an image position adjustment mechanism in the left-right direction that is the master width direction orthogonal to the master transport direction. The operator looks at the overprinted image, determines which color image is what, and based on this, operates the vertical image position adjustment mechanism or the horizontal image position adjustment mechanism to correct it. It has become.

[0004]

However, in the conventional method as described above, even when looking at the overprinted image itself, it is difficult to find out how much the relationship between which color and which color is shifted in which direction. There was a problem that it was difficult to judge.
Although this differs depending on the type of image, it is particularly difficult to determine the case of an image having many thick lines, a solid image or a photographic image. In the case of two-color printing, it is easy to some extent, but when the number of colors increases, they are mixed and difficult to understand. Since it is necessary to find out which part of the printed image should be used as a reference, it is difficult and requires skill for a beginner. Further, there is a problem that the operation itself of adjusting the image position shift is troublesome and requires skill.

Accordingly, the present invention can accurately and easily determine the difference between colors without requiring skill even if the number of colors is large.
It is an object of the present invention to provide a multicolor printing apparatus that can speed up the work of adjusting the image position shift. Another object of the present invention is to provide a multi-color printing apparatus capable of consistently automating the operation from the determination of the amount of displacement to the operation of adjusting the image position deviation, and realizing high accuracy of the operation of adjusting the image position deviation. .

In order to achieve the above object, according to the present invention, a plurality of printing drums, at least one plate making means for making a master based on color-specific plate making image data, A multi-color printing apparatus having a horizontal image position adjusting mechanism and a horizontal image position adjusting mechanism that is a master width direction orthogonal to the master transport direction, and capable of performing multi-color overprinting. In addition to the plate making based on the above, the plate making means forms a plate at the same position on the master with a positioning mark for print image position adjustment.

According to a second aspect of the present invention, in the multicolor printing apparatus according to the first aspect, a configuration is adopted in which the alignment marks are plate-made so that they can be distinguished for each color.

According to the third aspect of the present invention, the first or second aspect is provided.
In the multicolor printing apparatus described above, the alignment mark is configured by a combination of a device for confirming a vertical displacement and a device for confirming a lateral displacement.

According to the fourth aspect of the present invention, the first to third aspects are provided.
In the multi-color printing apparatus described in any one of the above, it is possible to easily confirm the amount of displacement of one of the plurality of alignment marks produced for each color at a different position with respect to the other alignment marks. It has a configuration that it has a shape.

According to the fifth aspect of the present invention, the first to fourth aspects are provided.
In the multicolor printing apparatus according to any one of the above, the alignment mark is formed at a leading end in a master conveying direction and an end in a master width direction in a master making image area so as to be inconspicuous with a thin line. Is adopted.

According to the sixth aspect of the present invention, the first to fourth aspects are provided.
In the multicolor printing apparatus according to any one of the above, the alignment mark is provided outside the master plate image area of the master,
A control unit that moves the image position with respect to the sheet by a predetermined amount only during printing for image position confirmation, and controls the image so that the alignment mark appears on the sheet and the image position can be confirmed. I am taking it.

According to the seventh aspect of the present invention, the first to sixth aspects are provided.
In the multi-color printing apparatus according to any one of the above, one of a plurality of alignment marks made for each color is used as a reference mark, and a shift amount of each of the other alignment marks with respect to the reference mark. Deviation input means for inputting
The apparatus has a control means for controlling a vertical image position adjusting mechanism or a horizontal image position adjusting mechanism based on the shift amount input by the shift amount input means.

According to an eighth aspect of the present invention, in the multicolor printing apparatus according to the seventh aspect, there is provided a drum identifying means for detecting a printing color of the printing drum, and the shift amount input means is detected by the detection of the drum identifying means. The printing color of each printing drum is automatically displayed.

According to the ninth aspect of the present invention, the first to sixth aspects are provided.
In the multicolor printing apparatus according to any one of the above, mark reading means for reading a registration mark of a printed sheet, a shift amount detecting means for detecting a shift amount based on the read information of the mark reading means, And a control means for controlling the vertical image position adjusting mechanism or the horizontal image position adjusting mechanism based on the shift amount detected by the shift amount detecting means.

According to a tenth aspect of the present invention, in the multicolor printing apparatus according to the ninth aspect, the mark reading means is C-type.
It is configured to be a CD camera.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, an outline of an overall configuration of a multicolor stencil printing apparatus as a multicolor printing apparatus according to the present embodiment and a control system will be described based on FIG. As shown in FIG. 1, the multicolor stencil printing apparatus 2 includes a first color (red) print drum 4, a second color (blue) print drum 6, and a third color (red) Black) printing drum 8. These printing drums 4, 6, and 8 are detachable from a drum mounting portion (not shown).

The printing drum 4 corresponds to the printing drum 4.
A plate discharging unit 10 for peeling off a used master, a plate making unit 12 for performing plate making of a master based on plate making image data obtained by processing a read image of a document, and supplying the plate finished master to the printing drum 4, A press roller 14 for pressing the sheet P against the printing drum 4 by a separation mechanism is provided. The same plate discharging unit 1 corresponding to the printing drum 6
6, a plate making unit 18 and a press roller 20 are provided, and a similar plate discharging unit 22, plate making unit 24 and press roller 26 are provided corresponding to the printing drum 8.

Further, top and bottom / left and right adjustment mechanisms 28, 30, and 32 are provided corresponding to the printing drums 4, 6, and 8, respectively. These include the image position adjustment mechanism in the vertical direction, which is the master transport direction, and the image position adjustment mechanism in the horizontal direction, which is the master width direction orthogonal to the master transport direction. The image position adjustment mechanisms are independent and independent mechanisms, and these are individually controlled by the control means described later. Although not shown, the top / bottom / left / right adjustment mechanisms 28, 30, and 32 have a well-known configuration. As the top / bottom image position adjustment mechanism, for example, a configuration described in Japanese Patent Application Laid-Open No. H10-297074 is used. Can be. As the image position adjustment mechanism in the left-right direction, for example, a configuration described in Japanese Patent Publication No. 2542489 can be adopted.

Drum identification means 34, 36 and 38 for detecting the printing colors of the printing drums are provided corresponding to the printing drums 4, 6 and 8, respectively. A scanner 40 for reading a document is provided at an upper portion of the apparatus main body (not shown), and image information of the document read by the scanner 40 is output to an image processing unit 44 directly or via a personal computer 42. It has become. The printing operation of the multicolor stencil printing apparatus 2 is controlled by control means 46 as a main controller. Control means 46 here
Means a microcomputer including a ROM, a RAM, an I / O interface, and the like. The control means 46 controls the image processing unit 44 to create a plurality of plate making image data separated for each color, and outputs this to each of the plate making units 12, 18 and 24. In each of the plate making units 12, 18, and 24, a thermal head (not shown) is driven based on the plate making image data.
Plate making is performed on a master (not shown).

Further, plate making data of a positioning mark for adjusting a print image position, which will be described later, is input to the image processing unit 44 through the personal computer 42 or the operation panel 48, and the plate making units 12, 18, and 24 are inputted. Thus, the alignment marks are made at the same position relative to the master image (claim 1).

Sheets P are fed one by one from a sheet feeding means (not shown). The fed paper P is temporarily stopped by a pair of registration rollers (not shown), and after correcting the oblique displacement or the like here, at the timing when the leading end of the image of the printing drum 4 of the first color coincides with the predetermined position in the feeding direction. The print drum 4 is sent to the print nip portion. The press roller 14 moves up in synchronization with this timing, and presses the sheet P against the print drum 4. The paper P on which the first color ink image has been transferred by the printing drum 4 subsequently enters the printing nip portion of the printing drum 6. The press roller 20 moves up in synchronization with this timing, and presses the sheet P against the print drum 6. The paper P on which the second color ink image has been transferred by the printing drum 6 subsequently enters the printing nip portion of the printing drum 8. The press roller 26 rises in synchronization with this timing, and presses the paper P against the print drum 8. The paper P on which the third color ink image has been transferred by the printing drum 8 is transported by transport means (not shown), and is stacked on a paper discharge tray (not shown).

The printing drums 4, 6, 8 have a known drum configuration. That is, although not shown, one or more mesh screen layers are provided on the outer peripheral surface of the porous cylindrical substrate, and the master is wound around the outer peripheral surface. An ink supply unit is provided inside the cylindrical substrate, and the ink supplied by the ink supply unit oozes out of the perforated portion of the master by the pressing force of the press rollers 14, 20, and 26, and onto the paper P. It is something that transfers.

As shown in FIG. 2, the drum discriminating means 34 is provided with a projection 3 formed at the tip of the printing drum 4 in the mounting direction.
4a, 34b, and sensors 34d, 34e, 34f provided on the drum mounting portion 50 of the printing drum 4.
The sensors 34d, 34e, 34f are also provided in the printing drums 6, 8. Projection 34a and sensor 34
The combination of d serves to detect the presence / absence of the drum, and the sensor 34d is turned on by the contact of the projection 34a. The presence / absence detection configuration includes the printing drums 4, 6, 8
Is provided in all of the. The sensors 34e and 34f detect the printing color of the attached printing drum. In the case of the printing drum 4, only the sensor 34e is turned on by the projection 34b, and the printing drum 6 has no projection and the sensor 34e, In the print drum 8, only the protrusion 34c is provided at a position corresponding to the sensor 34f, and only the sensor 34f is turned on. The drum identification means 30 and 32 have the same configuration.

Next, the alignment marks will be described in detail with reference to FIG. FIG. 3A shows a state in which printing has been performed on the printing drum 4 for the first color. The first color in the print image area (master plate making image area) of the paper P in the paper transport direction (master transport direction) and the edge in the paper width direction (master width direction) are indistinguishable by thin lines. An alignment mark M1 is formed (claim 5). FIG. 3B shows a state in which printing has been performed on the printing drum 6 for the second color. On the paper P, a second color alignment mark M2 is formed by a broken line together with the second color print image. FIG. 3C shows the printing drum 8 for the third color.
2 shows a state in which printing has been performed. On the paper P, together with the third color print image, the third color alignment mark M
3 is formed by an alternate long and short dash line. As described above, since the alignment marks M1, M2, and M3 are formed by solid lines, broken lines, and dashed lines so that they can be distinguished for each color, they can be easily distinguished even after three-color overprinting ( Claim 2).

Although the alignment mark M2 is formed on the master of the second color plate making unit 18 at the same position as the master of the first color, the position of the alignment mark M1 is changed due to a shift in the image position between the printing units. It is out of alignment. The alignment mark M3 is also made as a master in the third color plate making section 24 at the same position as that of the first color master, but is shifted from the position alignment mark M1 due to a shift in image position between the printing sections. .

As shown in FIG. 4, the alignment mark M1 serving as a reference includes a mark M1a for confirming the amount of displacement in the vertical direction and a mark M1b for confirming the amount of displacement in the left and right directions. Claim 3) and the mark M1a
Are extended in the width direction of the sheet P, and marks M1a and M1b are similarly formed at positions apart from each other. The alignment mark M2 includes a mark M2a for confirming the amount of displacement in the vertical direction and a mark M2b for confirming the amount of displacement in the left-right direction. Similarly, the alignment mark M3 is a mark M3 for confirming the amount of displacement in the vertical direction.
a and a mark M3b for confirming the shift amount in the left-right direction.
And consists of

As shown in FIG. 3C, for example, when the amount of displacement of the alignment mark M3 with respect to the alignment mark M1 is large, that is, when the positional deviation of the third color image with respect to the first color image is large, If there is only one cross-shaped alignment mark M1, the amount of deviation cannot be accurately grasped due to separation, but if two patterns are formed, the amount of deviation can be easily and accurately determined by comparison with the closer pattern. (Claim 4). In advance,
If the distance W between the marks M1b is known, the amount of displacement of the mark M3b in the alignment mark M3 can be easily determined. Further, there is an advantage that the shift amount of the second color image with respect to the first color image and the shift amount of the third color image with respect to the first color image can be easily and independently determined.

In this embodiment, the alignment mark M
Of the first, M2, and M3, the alignment mark M1 is used as a reference mark, and the respective shift amounts of the alignment marks M2 and M3 with respect to the alignment mark M1 are input to the operation panel 48 as a shift amount input unit. . As shown in FIG. 5, the operation panel 48 includes a numeric keypad 52, four arrow keys 54a, 54b, 54c, 54d, and a liquid crystal display unit 5.
6, a counter display unit 58 and the like. Liquid crystal display 5
6 displays a column for inputting the amount of displacement between the top and bottom directions and the left and right directions for the first color, the second color, and the third color. The operator determines the amount of misregistration in the overprinted image discharged by the printing operation or the trial printing by the alignment marks M1, M2, M3, and operates the ten key 52 and the arrow keys 54a, 54b, 54c, 54d. Input the deviation amount.

FIG. 6 shows an example of the shift amount input.
Since the alignment mark M1 is used as a reference, the first color is 0 in both the up-down direction and the left-right direction. The image of the second color is shifted by 2.0 to the upstream side in the transport direction in the vertical direction with respect to the image of the first color, and is shifted by 1.5 to the left in the transport direction in the horizontal direction. This shows the input state. Also, the third color image is shifted by 2.5 in the transport direction downstream in the vertical direction with respect to the first color image, and is shifted by 1.0 in the right and left direction in the transport direction in the horizontal direction. The input state for this is shown. The printing colors (red, blue, black) of the printing drum on the liquid crystal display unit 56 are determined by the drum identifying unit 34,
The information is automatically displayed based on the 36, 38 detection information (claim 8).

When a confirmation key (not shown) on the operation panel 48 is pressed, the control means 46 controls the vertical image position adjusting mechanism and the horizontal image position adjusting mechanism on the basis of the inputted shift amount, and controls the image position. (Claim 7).

In the above embodiment, the alignment mark M
1, M2, and M3 are formed in the print image area of the sheet P (the master plate making image area). However, since the alignment marks M1, M2, and M3 are actually printed, the quality of printed matter is affected. May be given. For this reason, it is also possible to adopt a configuration in which the alignment mark is made outside the master making image area of the master. This embodiment will be described below. The same parts as those in the above embodiment are denoted by the same reference numerals, and the description of the already-described configuration and function will be omitted unless necessary.

As shown in FIG. 7A, a positioning mark M1 is formed on the leading end of the master 60 in the master transport direction and at the end in the master width direction outside the plate making image area. The same applies to the masters of the second and third colors. In a normal printing operation, the alignment mark M1 does not appear on the paper P as shown in FIG. In the present embodiment, the control unit 46 controls the image position adjustment mechanism in the vertical direction so that the alignment mark M1 appears only at the time of printing for image position confirmation, that is, only at the time of printing operation or test printing. The image position on the sheet P is moved by a predetermined amount (F) (claim 6).

With this control, as shown in FIG. 7C, the alignment mark M1 (the alignment mark M
2 and M3 are omitted) on the paper P, and the amount of displacement by the alignment marks M1, M2 and M3 can be confirmed. Similarly to the above embodiment, when the shift amount is input by the shift amount input unit and the enter key is pressed, the control unit 46 adjusts the vertical image position adjusting mechanism and the horizontal image position adjustment based on the input shift amount. The mechanism is controlled so that the image position does not shift. After that, the image position adjusting mechanism in the vertical direction is controlled again to return the image position to the original amount by the predetermined amount (F), and the mode shifts to the normal continuous printing mode.

Next, another embodiment will be described with reference to FIG. The same parts as those in the above embodiment are denoted by the same reference numerals, and the description of the already-described configuration and function will be omitted unless necessary. In each of the above embodiments, the operator has to visually check the overprinted print image to determine the shift amount. However, in the present embodiment, the shift amount is eliminated mechanically and automatically by eliminating artificial ambiguity. It is characterized in that the deviation of the image position is corrected with high accuracy by grasping the position of the image.

The paper P on which the image of the third color is printed is conveyed by the conveying means 62, and is discharged and stacked on the discharge tray 64. At the upper end of the sheet abutment plate 64a of the sheet ejection base 64, the alignment marks M1 and M of the sheet P on which the overprinted image ejected by the plate attaching operation or the test printing is formed.
2. CCD as mark reading means for reading M3
A camera 66 is provided (Claim 10), and information read by the CCD camera 66 is input to the shift amount detecting means 68. The shift amount between the images is determined by the shift amount detecting means 68, and the shift amount is input to the control means 46. The control means 46 controls the image position adjustment mechanism in the vertical direction or the image position adjustment mechanism in the left-right direction based on the shift amount so that the image position does not shift (claim 9).

[0036]

According to the first aspect of the present invention, in addition to the plate making based on the plate-making image data for each color, the plate making means places the positioning mark for adjusting the print image position at the same position on the master. With this configuration, it is easy to know which color image is and how much, and the image position adjustment operation can be performed easily and quickly without requiring skill.

According to the second aspect of the present invention, since the plate is made so that the alignment marks can be distinguished for each color, it is very easy to know which color image is and how much. The adjustment operation can be performed easily and quickly without requiring skill.

According to the third aspect of the present invention, the positioning mark is constituted by a combination of one for checking the amount of displacement in the vertical direction and one for checking the amount of displacement in the horizontal direction. It is easy to find out how much the color image is in the up-down direction and the left-right direction, and the image position adjustment operation can be performed easily and quickly without requiring any skill.

According to the fourth aspect of the present invention, one of the plurality of alignment marks formed for each color has a shape in which the amount of displacement can be easily confirmed at a different position with respect to the other alignment marks. , The amount of shift can be easily determined even if the amount of shift between the second color image and the third color image with respect to the first color image is large. Further, the shift amount of the second color image with respect to the first color image and the shift amount of the third color image with respect to the first color image can be independently determined.

According to the fifth aspect of the present invention, the positioning mark is formed on the master in the master making direction in the master conveying direction and at the end in the master width direction so as to be inconspicuous with a thin line. With the configuration, the influence on the quality of the printed matter can be reduced.

According to the sixth aspect of the present invention, the positioning mark is provided outside the plate making image area of the master, and the image position with respect to the sheet is moved by a predetermined amount only during printing for image position confirmation. Since the control means is provided so as to control the mark to appear on the sheet so that the image position can be confirmed, it is possible to eliminate the influence of the formation of the alignment mark on the quality of the printed matter.

According to the seventh aspect of the present invention, one of a plurality of alignment marks produced for each color is used as a reference mark, and a shift amount of each of the other alignment marks with respect to the reference mark is determined. A shift amount input means for inputting, and a control means for controlling a vertical image position adjustment mechanism or a horizontal image position adjustment mechanism based on the shift amount input by the shift amount input means. Therefore, the shift amount can be easily determined, and the image position adjusting operation can be easily and quickly performed without requiring any skill.

According to the eighth aspect of the present invention, there is provided a drum identifying means for detecting a printing color of the printing drum, and the printing color of each printing drum is automatically inputted to the shift amount input means by the detection of the drum identifying means. Is displayed, the input operation of the shift amount can be easily performed without error.

According to the ninth aspect of the present invention, there is provided a mark reading means for reading an alignment mark of a printed sheet, a shift amount detecting means for detecting a shift amount based on information read by the mark reading means, It is configured to have a control means for controlling the vertical image position adjusting mechanism or the horizontal image position adjusting mechanism based on the shift amount detected by the shift amount detecting means, so that the shift amount can be accurately grasped. It is possible to perform image position adjustment with high accuracy while eliminating artificial ambiguity.

According to the tenth aspect of the present invention, since the mark reading means is constituted by a CCD camera, the mark reading structure can be reduced in size and the size of the apparatus can be prevented as much as possible.

[Brief description of the drawings]

FIG. 1 is a front view illustrating a schematic configuration and a control system of a multicolor stencil printing apparatus as a multicolor printing apparatus according to an embodiment of the present invention.

FIG. 2 is a main part plan view showing a drum identification unit.

FIG. 3 is a diagram showing a state of forming a positioning mark;
(A) is a plan view showing a state in which printing of the first color has been completed, (b)
FIG. 3C is a plan view showing a state where printing of a second color has been completed, and FIG. 3C is a plan view showing a state where printing of a third color has been completed.

FIG. 4 is an enlarged view of a main part showing a positioning mark.

FIG. 5 is a schematic plan view of an operation panel as a shift amount input unit.

FIG. 6 is a schematic plan view of a liquid crystal display unit showing a state of input of a shift amount.

FIGS. 7A and 7B are diagrams showing a state of forming a positioning mark according to another embodiment, wherein FIG. 7A is a plan view showing a forming position on a master, and FIG. 7B is a view showing the positioning mark when printing is performed. FIG. 3C is a plan view showing a state where the image is not shifted, and FIG. 4C is a plan view showing a state where an alignment mark appears on the sheet by shifting the image position.

FIG. 8 is a front view of a main part of a multicolor stencil printing apparatus according to another embodiment.

[Explanation of symbols]

 4, 6, 8 Printing drum 60 Master 12, 18, 24 Plate making section as plate making means M1, M2, M3 Positioning mark F Predetermined amount 46 Control means 48 Operation panel as shift amount input means 34, 36, 38 Drum Identification means 65 CCD camera as mark reading means

Claims (10)

[Claims] 1. A plurality of printing drums, at least one plate making means for making a master based on plate-making image data for each color, an image position adjusting mechanism in a vertical direction which is a master transport direction, and an orthogonal to the master transport direction. A multi-color printing apparatus having an image position adjusting mechanism in the left-right direction that is the master width direction and capable of multi-color overprinting. A multicolor printing apparatus, wherein a positioning mark for image position adjustment is made at the same position on a master. 2. A multi-color printing apparatus according to claim 1, wherein said alignment marks are made in a plate-making manner so as to be distinguishable for each color. 3. The multicolor printing apparatus according to claim 1, wherein the alignment mark is a combination of a mark for confirming a shift amount in a vertical direction and a mark for checking a shift amount in a left-right direction. A multicolor printing apparatus characterized by the above-mentioned. 4. A multi-color printing apparatus according to claim 1, wherein one of the plurality of alignment marks produced for each color is made different from the other alignment marks. A multi-color printing apparatus having a shape in which a shift amount can be easily confirmed at different positions. 5. The multicolor printing apparatus according to claim 1, wherein the alignment mark is a leading end in a master conveying direction in a master plate image area and an end in a master width direction. A multicolor printing apparatus characterized in that plate making is performed in such a manner that a thin line does not stand out. 6. A multicolor printing apparatus according to claim 1, wherein said alignment mark is provided outside a master plate image area, and said mark is provided only when printing for image position confirmation. A multi-color printing apparatus comprising: a control unit that controls an image position with respect to the sheet only so that the alignment mark appears on the sheet so that the image position can be confirmed. 7. A multi-color printing apparatus according to claim 1, wherein one of a plurality of alignment marks produced for each color is used as a reference mark, and another one of said plurality of alignment marks is used as a reference mark. A shift amount input means for inputting a shift amount of each of the positioning marks, and a vertical image position adjusting mechanism or a horizontal image position adjusting mechanism based on the shift amount input by the shift amount input means. A multi-color printing apparatus, comprising: 8. A multi-color printing apparatus according to claim 7, further comprising: a drum identification unit for detecting a print color of said printing drum, and printing of each printing drum to said shift amount input unit by detection of said drum identification unit. A multi-color printing apparatus characterized in that colors are displayed automatically. 9. A multi-color printing apparatus according to claim 1, wherein said mark reading means reads a positioning mark of a printed sheet, and said mark reading means reads said mark reading means based on information read by said mark reading means. A shift amount detecting means for detecting the shift amount, and a control means for controlling the vertical image position adjusting mechanism or the horizontal image position adjusting mechanism based on the shift amount detected by the shift amount detecting means. A multicolor printing apparatus characterized by the above-mentioned. 10. The multicolor printing apparatus according to claim 9, wherein said mark reading means is a CCD camera.