JP2002049200A - Printing position adjusting method for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing position adjusting method for an image forming device performing correction adjustment not only on black(B) reference but also between cyan (C) and magenta(M). SOLUTION: In this image forming device, printing deviation is avoided by acquiring correction values on the printing positions of three colors with black(B) as reference, acquiring a correction value on the deviation of the printing position between magenta(M) and cyan(C) being conspicuous colors thereafter and adjusting the printing position by using both correction values. The image forming device having more excellent printing quality by performing the correction between magenta(M) and cyan(C) being the conspicuous colors especially is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position adjusting device and a position adjusting method for an image forming apparatus.

[0002]

2. Description of the Related Art In recent years, color printers have become widespread, and color printers of various types are commercially available. Among them, printer devices using a tandem system are excellent in printing speed and are widely used. However, since image forming units for yellow (Y), magenta (M), cyan (C), and black (B) are arranged in parallel and printing is performed sequentially, mounting accuracy of each unit is required and printing position adjustment is performed. Need to do.

Conventionally, the above printing position adjustment is performed in black (B)
, The print position is adjusted for yellow (Y), magenta (M), and cyan (C). For example, FIG.
Prints yellow (Y) on the black (B) frame pattern, detects yellow (Y) printing deviation from black (B), and performs adjustment. FIG. 14 shows a printing result when the printing position of yellow (Y) is not shifted with respect to black (B).

Also, other magenta (M), cyan (C)
The same applies to the case where the shifts of magenta (M) and cyan (C) with respect to black (B) are detected, respectively.
The print position is being adjusted.

[0005]

However, in the above-mentioned conventional system, the printing position deviation of yellow (Y), magenta (M), and cyan (C) with respect to black (B) is adjusted. The deviation of the printing position of other colors can be adjusted. However, it is not possible to cope with a printing position shift between yellow (Y) and magenta (M), between yellow (Y) and cyan (C), and between magenta (M) and cyan (C).

In particular, the colors of magenta (M) and cyan (C) are conspicuous, and the displacement is conspicuous when a positional displacement occurs.
The printing quality is significantly reduced. FIG. 15 and FIG. 16 are diagrams for explaining this. First, the printing example of FIG.
This is a state where there is no shift in the printing positions of the four colors. For example, yellow (Y), cyan (C), magenta (M), and black (B) are sequentially printed (laminated) from the bottom without causing a positional shift. . Therefore, in this case, black printing is performed at an accurate position by, for example, heat fixing with a fixing device.

[0007] On the other hand, in the case of FIG. 16, the printing position is shifted. For example, in the case of FIG. 16A, cyan (C) and magenta (M) are shifted by one dot, and in the case of FIG. 16B, cyan (C) and magenta (M) are shifted by one dot. I have. In the case of FIG. 3C, yellow (Y) and magenta (M) are shifted by one dot. Therefore, if a shift of one dot occurs as described above, an accurate color does not follow the subtractive color mixture, leading to a decrease in print quality.

[0008] However, the above-mentioned printing also occurs according to the conventional method. That is, in both the printing states of FIGS. 16A to 16C, yellow (Y), cyan (C), and magenta (M) are shifted from each other by a maximum of 0.5 dot with respect to black (B). According to the conventional print position adjustment, this is a range that is not regarded as a print position shift.

However, even in the above case, one dot is printed between yellow (Y) and cyan (C), between magenta (M) and cyan (C), and between yellow (Y) and magenta (M). Misalignment occurs. In such a case, the print quality is deteriorated, and in particular, one is applied to magenta (M) and cyan (C) in which colors are conspicuous.
It is a problem if there is a dot shift.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and the object thereof is to perform not only the black reference but also the correction of the printing position between magenta (M) and cyan (C). Another object of the present invention is to provide a print position adjusting device for forming an image with excellent print quality.

[0011]

SUMMARY OF THE INVENTION According to the present invention, the above objects are attained by yellow (Y), magenta (M), cyan (C),
In an image forming apparatus in which image forming units for forming a black (B) image are sequentially arranged and a color image is formed on a sheet to be conveyed, the image forming unit is configured based on the black (B).
First to adjust the correction value of the image forming position of each other color
And adjusting the correction value of the printing position shift between magenta (M) and cyan (C) after the adjustment by the correction value.
This is achieved by providing a print position adjustment method for an image forming apparatus that performs the adjustment of the print position.

Further, according to the present invention, there is provided an image forming unit for forming yellow (Y), magenta (M), cyan (C), and black (B) images sequentially and is conveyed. In an image forming apparatus for forming a color image on a sheet, detection of correction values of image forming positions of other colors and printing position between magenta (M) and cyan (C) with reference to the black (B). The present invention is attained by providing a position adjustment method of an image forming apparatus that simultaneously detects a shift correction value and adjusts a printing position of each color according to the correction value after the detection.

Further, according to the present invention, there is provided an image forming unit for forming yellow (Y), magenta (M), cyan (C), and black (B) images sequentially, and is conveyed. In an image forming apparatus for forming a color image on a sheet, printing by the yellow (Y), magenta (M), and cyan (C) image forming units is performed at the same position, and the yellow (Y), magenta (M), Achieved by providing a position adjusting method for an image forming apparatus, wherein the position of one color in cyan (C) is shifted and the printing position of each color is adjusted by checking the color of black printing. Is done.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 1 shows an image forming apparatus according to the present embodiment, which is an example of a so-called tandem type color printer. The image forming apparatus of the present embodiment is a printer for double-sided printing. In the figure, the printer device is connected to a host device such as a personal computer by a cable (not shown).

The printer comprises an image forming section 1, a transport unit 2 for double-sided printing, and a paper feeding section 3. Here, the image forming unit 1 includes four image forming units 14 to 17.
Are arranged in parallel from the right side to the left side of the drawing, magenta (M), cyan (C), yellow (Y),
They are arranged in the order of black (K). The magenta (M), cyan (C), and yellow (Y) image forming units 14 to 16 are configured to perform color printing by subtractive color mixing, and the black (K) image forming unit 17 is configured to perform monochrome printing. Used for

Here, each of the image forming units 14 to 17 includes a drum set C1 and a toner set C2, and has the same configuration except for the (color of) the developer stored in the developing container. Therefore, the configuration will be described using the image forming unit 16 for yellow (Y) as an example. A photosensitive drum 20, a charger 21a, a cleaner 21e, and the like are stored in the drum set C1, and a print head 21b is disposed above the drum set C1. Toner set C
2 contains a developing roll 21c and toner.

The peripheral surface of the photosensitive drum 20 is made of, for example, an organic photoconductive material. Near the peripheral surface of the photosensitive drum 20, a charger 21a, a print head 21b, a developing roll 21c, a transfer unit 21d, Cleaners 21e are sequentially provided. The photoreceptor drum 20 rotates in the direction of the arrow, and first charges the peripheral surface of the photoreceptor drum 20 uniformly by applying a charge from the charger 21a. Then, the photosensitive drum 2 is written by optical writing based on print information from the print head 51b.
Then, an electrostatic latent image is formed on the peripheral surface of No. 0, and a toner image is formed by a developing process using the developing roll 21c. At this time, the toner image formed on the peripheral surface of the photosensitive drum 20 is
c) based on the yellow (Y) toner stored in c. The toner image formed on the peripheral surface of the photosensitive drum 20 in this way reaches the position of the transfer unit 21d with the rotation of the photosensitive drum 20 in the direction of the arrow, and immediately below the photosensitive drum 20 in the direction of the arrow. It is transferred to the moving paper.

On the other hand, the paper is conveyed by a paper cassette 4, a standby roll 5, a conveying belt 6,
The sheet transported from the sheet feed cassette 4 by the rotation of the sheet feed roller 9 is sent to the standby roller 5 and further sent to the transport belt 6 at a timing coincident with the toner image. Each transfer device 21d is reached. And
The toner image is transferred to each transfer unit 21 d, and the sheet on which the toner image has been transferred moves on the transport belt 6 in the direction of the arrow according to the movement of the transport belt 6, and is subjected to heat fixing processing in the fixing unit 10.

On the upper surface of the sheet, not only the yellow (Y) toner image but also the magenta (M) and cyan (C) toner images are transferred, and the printing of the color according to the subtractive color mixture is performed. Is performed. The above-mentioned paper includes not only the paper carried out of the paper feed cassette 4 but also the paper supplied from the MPF tray 8. In this case, the paper is carried in by the paper feed roller 8a and printed by the aforementioned path. Processing is performed.

Further, the fixing unit 10 includes a heat roll 1
While the paper is nipped and conveyed between the above-mentioned heating rolls 10a and 10b, for example, a plurality of color toner images transferred to the paper are melted and thermally fixed to the paper. The cleaning roll 10c has a function of applying a release oil to the peripheral surface of the heat roll 10a and removing toner remaining on the heat roll 10a. The sheet on which the toner image has been fixed by the fixing unit 10 is conveyed upward or leftward on the sheet via the switching plate 31.

On the other hand, the double-sided printing unit 2 is configured to be detachable from the apparatus main body, and is a unit to be mounted when performing double-sided printing by the printer of the present embodiment. Is established. In the case of double-sided printing, the sheet is once sent upward by the switching plate 31, and when, for example, the rear end of the sheet reaches the transport roll 32, the transport of the sheet is stopped and the sheet is transported in the reverse direction. According to this control, the sheet is conveyed downward on the left side of the switching unit 31 set at the position indicated by the dotted line, and is conveyed into the sheet conveying path of the conveying unit 2 for double-sided printing.
The paper is fed by a to 30e, reaches the standby roll 5, and is sent to the transfer unit at the same timing as the toner image as described above, and the toner image is transferred to the back surface of the paper. FIG. 2 is a diagram for explaining a circuit system in the printer device having the above configuration. In the figure, a circuit system includes a printer interface (I / F) 41, a printer controller 42, a CPU 43, a ROM 44, an EEPROM 45,
An operation panel 46, a printer printing unit 47, and a ROM
Reference numeral 44 stores an X correction and Y correction chart.
Further, the X correction value and the Y correction value input from the operation panel 46 are written in the EEPROM 45.

Normal print data is supplied from a host device (not shown), converted into bitmap data by the I / F 41, and then supplied to the printer controller 42, where yellow (Y), cyan (C), and magenta (M) are provided. , Black (B), and is output to the printer printing unit 47 to perform printing processing on paper.

On the other hand, the printing position adjustment of this embodiment is performed as follows. FIG. 3 is a flowchart for explaining the processing of the present embodiment. First, the printing position shift of each color with respect to black (B), which is the same as the conventional case, is checked. First, an adjustment chart is output from the operation panel 46 or an external input (step (hereinafter, referred to as S) 1). Here, FIG. 4 is an example of the output adjustment chart used in the present example. In the case of the pattern 1a, the white (blank) is 2
Dots and black (B) are continuous of 5 dots, and another color is printed in the area of 2 dots of white (blank).

In the case of the pattern 1b, two white (blank) dots and two black (B) dots are continuous, and another color is printed in the two white (blank) dot area. further,
In the case of the pattern 1c, one dot of white (blank) and one dot of black (B) are continuous, and another color is printed in the area of one dot of white (blank).

FIG. 5 is a diagram in which patches having the above configuration are formed for each color. For example, the correction values are sequentially changed on a sheet or a transport belt and continuously formed. Therefore, the amount of print misregistration of yellow (Y), magenta (M), and cyan (C) with respect to black (B) can be determined from this patch.

Next, the correction value read from the adjustment chart is input from an operation panel or the like, and a check chart taking into account the correction value is output, and the adjustment for black (B) is checked by the correction value (S2). Next, the amount of deviation between cyan (C) and magenta (M) is checked using a deviation correction chart for cyan (C) and magenta (M). 6 and 7 are views showing the state of the patch formation at this time.
Is for Y direction correction, and FIG. 7 is for X direction correction. FIG. 8 is a diagram for explaining the patch formation state of FIG. 6 or 7 in more detail. In the figure, adjustment is performed by sliding magenta (M) by one dot with respect to cyan (C).

FIG. 9 shows a flow of the adjustment mode.
When the adjustment mode starts, a print deviation adjustment chart is output (STP1). Requests input of adjustment value (S
TP2). Next, when the input data is the initial value (Y in STP3), a confirmation chart is output, and the correction values of the deviation correction chart of cyan (C) and magenta (M) are read and input (STP4). And finally EEP
The X correction value and the Y correction value are stored in the ROM 45 (STP
5), end the processing.

By performing the processing as described above, in addition to the printing position shift of each color with respect to the black (B) reference,
In particular, position correction for a conspicuous color is performed, and more accurate printing can be performed. As described above, in this example, a high-precision correction can be performed without using a loupe or the like, and the correction can be easily performed not only by a service person but also by a user. Further, image quality is improved by further adjusting cyan and magenta after adjusting based on black. <Second Embodiment> Next, a second embodiment of the present invention will be described.

In this embodiment, the reference chart for black (B) and the correction for magenta (M) and cyan (C) are performed in the same manner. For example, they are formed on the same sheet of paper. Hereinafter, a specific description will be given. The flowchart of FIG. 10 explains the processing of this example. First, an adjustment chart is supplied from an operation panel or an external input (step (hereinafter referred to as ST)).
1). By this process, the chart shown in FIG. 5 and the charts shown in FIGS. 6 and 7 are formed on the same sheet. Therefore, the other three for black (B)
The color shift amount and the shift amount between magenta (M) and cyan (C) are read simultaneously. In addition, the shift amount can be read in the X direction and the Y direction.

Next, a correction value read from the black (B) reference chart and a correction value between magenta (M) and cyan (C) are input from the operation panel 46, for example (ST).
2). Next, the distance between magenta (M) and cyan (C) of the correction value read from the black (B) reference chart is read out as “S”, and the correction value between magenta (M) and cyan (C) is read as “S”. T "(ST3).

Next, when the difference between "S" and "T" is "0", the correction value read from the black (B) reference chart is directly written into the EEPROM 45 (ST4).
On the other hand, when the difference between “S” and “T” is other than “0”,
For example, when the difference between “S” and “T” is “1”, the accuracy of “S” is one dot with respect to black (B), so the following example is obtained. For example, when the correction values of black (B) and cyan (C) are “5”, the actual shift is 4.
5 to 5.5 dots, and when the correction values of black (B) and magenta (M) are “−6”, the actual deviation is −5.5.
-6.5 dots. Therefore, when the actual deviation is 4.5 dots for cyan (C) and 5.5 dots for magenta (M), the correction value C from black (B) is 5, and M
If it is kept at −6, the correction values of magenta (M) and cyan (C) are shifted by one dot (at this time, S = 11).

Then, since the correction value of magenta (M) -cyan (C) is T = 10, it becomes ST and (F =
1), the correction value for cyan (C) is 5-F / 2 = 4.5, and the correction value for magenta (M) is -6 + F / 2 = -5.5. Therefore, the position correction based on the black (B) is also performed, and the position correction between magenta (M) and cyan (C) is also performed, so that the printing accuracy can be improved.

The following configuration may be adopted in addition to the first and second embodiments. Hereinafter, a specific description will be given. For example, when each color of yellow (Y), magenta (M), and cyan (C) overlaps, black printing is performed, and the black printing is detected to correct a printing shift.

FIG. 11 is a diagram for explaining this example. That is, yellow (Y), magenta (M), cyan (C)
Are printed at the same position, and only the position of cyan (C) is shifted as shown in FIG. FIG. 12 shows the correction values for yellow (Y). In this way, the correction value of a certain color is varied,
The correction value of each color can be set by checking the black that has been synthesized and printed.

[0035]

As described above, according to the present invention,
High-precision correction can be performed without using a loupe. It is easy for users as well as servicemen. Further, image quality is improved by adjusting cyan, magenta, and yellow after adjusting based on black.

[Brief description of the drawings]

FIG. 1 is an image forming apparatus according to an embodiment, which is an example of a so-called tandem type color printer.

FIG. 2 is a diagram illustrating a circuit system in the printer device.

FIG. 3 is a flowchart illustrating a first embodiment.

FIG. 4 is a chart based on black (B) for explaining the first embodiment.

FIG. 5 is a black (B) reference chart illustrating the first embodiment.

FIG. 6 is a magenta (M) -cyan (C) chart illustrating the first embodiment.

FIG. 7 is a magenta (M) -cyan (C) chart illustrating the first embodiment.

FIG. 8 is a specific example of a magenta (M) -cyan (C) chart illustrating the first embodiment.

FIG. 9 is a flowchart illustrating a first embodiment.

FIG. 10 is a flowchart illustrating a second embodiment.

FIG. 11 is a diagram illustrating a third embodiment.

FIG. 12 is a diagram illustrating a third embodiment.

FIG. 13 is a diagram illustrating a conventional example.

FIG. 14 is a diagram illustrating a conventional example.

FIG. 15 is a diagram illustrating a conventional example.

FIG. 16 is a diagram illustrating a problem of the conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Image forming unit 2 Double-sided printing transport unit 3 Paper feed unit 4 Paper feed cassette 5 Stand-by roll 6 Transport belt 7 Drive roll 8a Feed roller 9 Feed roller 10 Fixing unit 10a, 10b Heat roll 10c Cleaning roll 30a-30e Transport Roll 31 Switching plate 32 Conveying roll 41 Printer interface (I / F) 42 Printer controller 43 CPU 44 ROM 45 EEPROM 46 Operation panel

Continued on the front page F term (reference) 2C262 AA04 AA24 AA26 AA27 AB15 FA02 FA05 FA13 GA04 GA32 GA36 GA40 GA42 2H030 AA01 AA07 AB02 AD17 BB02 BB16 BB21 BB41 BB63 2H076 AB16 AB67 AB68 EA01

Claims (4)

[Claims] An image forming unit for sequentially forming an image forming unit for forming yellow (Y), magenta (M), cyan (C), and black (B) images and forming a color image on a conveyed sheet is provided. In the apparatus, a first adjustment for adjusting a correction value of an image forming position of each of the other colors with reference to the black (B), and an adjustment between the magenta (M) and the cyan (C) after the adjustment based on the correction value. And a second adjustment for adjusting the correction value of the print position deviation of the image forming apparatus. 2. An image forming unit for sequentially forming image forming units for forming yellow (Y), magenta (M), cyan (C), and black (B) images to form a color image on a conveyed sheet. In the apparatus, detection of a correction value of an image forming position of each other color and detection of a correction value of a printing position shift between magenta (M) and cyan (C) are simultaneously performed based on the black (B). And adjusting the printing position of each color according to the correction value after the detection. 3. An image forming unit which sequentially arranges image forming units for forming yellow (Y), magenta (M), cyan (C), and black (B) images and forms a color image on a conveyed sheet. In the apparatus, printing by the yellow (Y), magenta (M), and cyan (C) image forming units is performed at the same position, and one of the yellow (Y), magenta (M), and cyan (C) is printed.
A position adjusting method for an image forming apparatus, comprising: adjusting a printing position of each color by shifting a color position and confirming a black printing color. 4. The apparatus according to claim 1, wherein the correction value is obtained in each of a main scanning direction and a sub-scanning direction.
Or the position adjustment method of the image forming apparatus according to 3.