JP2883707B2 - Method and apparatus for measuring displacement of color printing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Table of Contents] Overview Industrial application Field of the Invention Problems to be Solved by the Invention Means for Solving the Problems (FIG. 1) Action Embodiment (a) Description of Color Printing Apparatus ( (FIG. 2) (b) Description of the first embodiment (FIGS. 3 to 7) (c) Description of the second embodiment (FIGS. 8 to 13) (d) Other embodiments Description [Effects of the Invention] [Overview] In a color printing apparatus that performs color printing by recording a plurality of recording units in different colors, a position shift measuring method for adjusting the position shift of the recording unit and the apparatus are provided. In a color printing apparatus for performing color printing on a recording medium by a plurality of recording units each having a different recording color for the purpose of automatically measuring a shift amount, a pattern reader for reading a recording pattern of each color of the recording medium is provided. Provided, The plurality of recording units record measurement patterns in each recording color on the recording body, read the measurement patterns of each color on the recording body with the pattern reader, and control the position of the measurement pattern of each color read by the control means. The measurement is performed, and the measurement position information of each recording unit is displayed on the display means.

[Industrial applications]

The present invention relates to a position shift measuring method for adjusting a position shift of a recording unit in a color printing apparatus that performs color printing by recording a plurality of recording units in different colors, and an apparatus thereof.

With the development of image technology in recent years, the demand for color printing has increased, and color printing apparatuses based on an electrophotographic system, an electrostatic recording system, a thermal transfer recording system, an ink jet system, and the like have been proposed.

In a color printing device, a plurality of recording units such as an electrophotographic unit are provided, and the recording units perform recording in different colors on paper and perform color printing. Therefore, if the recording positions of the recording units do not completely match, Color shift and dot shift occur.

For this reason, it is necessary to detect the recording position deviation of each recording unit and adjust its mechanical position.

[Conventional technology]

For example, in a color printing apparatus including four recording units for recording four colors of yellow (Y), magenta (M), cyan (C), and black (K), each recording unit is on a single sheet of paper. In each color, a measurement pattern called a cross-shaped register mark composed of a vertical line and a horizontal line is recorded.

The position of the measurement pattern on the paper is measured visually, the amount of displacement is measured by a measure or the like, and thereby the mechanical displacement of each recording unit is adjusted.

[Problems to be solved by the invention]

However, the prior art has the following problems.

It is necessary to visually read the amount of misalignment due to the measurement pattern, which requires skill, and it is difficult and time-consuming to accurately read the amount of misalignment.

Even when the recording unit is replaced during maintenance of the printing apparatus, it is necessary to adjust the recording position, which takes a long time and leads to a decrease in service.

Accordingly, it is an object of the present invention to provide a method and a device for measuring a displacement of a color printing apparatus, which can automatically measure a displacement amount due to a measurement pattern.

[Means for solving the problem]

 FIG. 1 is a diagram illustrating the principle of the present invention.

According to a first aspect of the present invention, in a color printing apparatus for performing color printing on a recording medium PP by a plurality of recording units 10 to 13 having different recording colors, a pattern reading apparatus for reading a recording pattern of each color of the recording medium PP. A recording device PP is provided.
The measurement pattern is recorded in each recording color by the plurality of recording units 10 to 13, the measurement pattern of each color on the recording medium PP is read by the pattern reader 19, and the position of the measurement pattern of each color read is controlled. The measurement is performed by the means 20 to obtain measurement position information.

In claim (2) of the present invention, in claim (1),
The measurement position information is displayed on the display means 21.

In claim (3) of the present invention, in claim (1),
The measurement position information is characterized by a recording inclination amount of each of the recording units 10 to 13 and a positional deviation amount in the main scanning direction.

In claim (4) of the present invention, in claim (3),
The measurement pattern is a pattern in which a horizontal line and a vertical line are combined.

In claim (5) of the present invention, in claim (3),
The measurement pattern is a pattern obtained by combining a horizontal line and an oblique line.

In claim (6) of the present invention, in claim (1),
The control means 20 responds to a recording position adjustment mode instruction by
It is characterized in that the measurement patterns are recorded in the recording units 10 to 13.

According to a seventh aspect of the present invention, in a color printing apparatus for performing color printing on a recording medium PP by using a plurality of recording units 10 to 13 having different recording colors, the plurality of recording units 10 to 13 are recorded on the recording medium PP. And a pattern reader 19 for reading the measurement pattern of each color on the recording medium PP.
20 is characterized in that it measures the position of the read measurement pattern of each color and obtains measurement position information.

In claim (8) of the present invention, in claim (7),
A display means 21 for displaying the measurement position information is provided.

In claim (9) of the present invention, in claim (8),
The display means 21 is provided in the color printing apparatus.

In claim (10) of the present invention, in claim (7),
The control means 20 records the measurement pattern in each of the recording units 10 to 13 in response to a recording position adjustment mode instruction.

In claim (11) of the present invention, in claim (7),
The pattern reader 19 comprises three primary color light emitting diodes and CC.
It is a D-line sensor.

In claim (12) of the present invention, in claim (7),
The pattern reader 19 comprises three primary color light emitting diodes;
It is characterized by a slit and an optical sensor.

[Action]

According to claims (1) and (7) of the present invention, a pattern reader is provided.
Since the control unit 20 and the control unit 19 are provided, the displacement amount can be automatically measured from the recording medium PP on which the measurement pattern is printed.

For this reason, it is not necessary to visually measure the amount of displacement. In addition, since the measurement is performed in the printing apparatus, accurate measurement can be performed.

In claims (2) and (8) of the present invention, the measured position information is displayed on the display means 21, which is convenient for manual adjustment of the positional deviation.

According to the third aspect of the present invention, since the inclination and the main scanning position deviation are measured, the main recording position deviation can be measured.

In claims (4) and (5) of the present invention, the positional deviation of claim (3) can be measured by the measurement pattern.

According to claims (6) and (10) of the present invention, the recording unit 10
The automatic measurement can be executed only by giving a mode instruction to the control means 20 for controlling the control of.

In claim (9) of the present invention, since the display means 21 is provided in the apparatus, it is convenient for confirming the measured amount and can also be used as the display means in the apparatus.

According to claims (11) and (12) of the present invention, the measurement pattern of each color can be read with a simple configuration.

〔Example〕

(A) Description of the color printing apparatus FIG. 2 is a diagram showing the configuration of the color printing apparatus of the present invention.
1 shows an electrophotographic color printer using an array.

In the figure, the same components as those shown in FIG. 1 are denoted by the same symbols.

This printer includes four recording units 10 to 13. Each of the recording units 10 to 13 has a photosensitive drum 100
And a charger 101 for pre-charging the photosensitive drum 100, and an LE having one line of LEDs for exposing the photosensitive drum 100 to an optical image.
D array 102 and developing unit 1 for developing latent image on photosensitive drum 100
03, a transfer device 104 for transferring the toner image of the photosensitive drum 100 onto paper, and a cleaner 105 for cleaning the photosensitive drum 100.
An image with toner is formed on 0.

Numeral 14 denotes a fixing device, which fuses and fixes the toner on the paper on which the transfer has been performed four times by heat, numeral 15 denotes a paper cassette which holds the paper to be recorded, and numeral 16 denotes a paper cassette. A pickup roller for taking out the paper from the paper cassette 15; 17 a recording paper transport system, which feeds the paper taken out by the pickup roller 16 into four sets of recording units 10 to
Reference numeral 18 denotes a stacker for passing the sheet through the fixing device 13 and feeding the sheet to the fixing device 14. The stacker 18 stores the sheet discharged from the fixing device 14.

Reference numeral 19 denotes a pattern reader, which is provided between the fixing unit 14 and the stacker 18 and has fixed paper (hereinafter also referred to as recording paper).
A sheet guide 18a for optically reading the above measurement pattern is a sheet guide, which guides the sheet PP in the pattern reader 19.

 The operation of this color printer is as follows.

Developers of yellow (Y), magenta (M), cyan (C), and black (K) are put in the developing units 103 of the recording units 10 to 13, respectively.

The paper in the paper cassette 15 is taken out by a pick-up roller 16 and is transported by a paper transport system 17 to each of the recording units 10 to 10.
Transported under 13.

On the other hand, in each of the recording units 10 to 13, an electrophotographic recording is performed, and an image is formed on the photosensitive drum 100 using the developer of each color.

When the paper comes under each photosensitive drum 100, the photosensitive drum 1
The toner image on 00 is transferred to a sheet by each transfer unit 104. The sheet on which the transfer has been performed four times is fixed in the fixing device 14 by melting the toner by heat and output to the stacker 18.

Since the printer of this configuration uses an LED array, it is a solid-state scan and does not require any mechanical driving parts.
Further, the optical path length can be shortened, the size of the apparatus can be reduced, and the price can be reduced due to the advancement of semiconductor technology, so that a compact printer can be realized.

In addition, since the electrophotographic system can perform high-speed recording, a high-speed color printer can be realized.

Further, since each recording unit performs a recording operation in parallel with the pipeline system, high-speed color recording is possible.

In a printer using such an LED array, if the exposure dot position of each LED array is different, a color shift occurs and an image is deteriorated.

For this reason, it is necessary to adjust each dot position of the LED array, particularly the inclination, and the dot position in the main scanning direction.

(B) Description of First Embodiment FIG. 3 is an explanatory diagram of a pattern reader according to the first embodiment.

As shown in FIG. 3 (A), the pattern reader 19 emits light of three primary colors, ie, blue (B), green (G), and red (R) light emitting diodes 190, 191, 192, which irradiate the recording paper PP. And a CCD line sensor 194 that receives the reflected light and converts it into an electric signal.

As shown in FIG. 3B, a pair of pattern readers 19a and 19b are provided at both ends in the paper feeding direction of the recording paper PP.

On the other hand, on the recording paper PP, a cross-shaped measurement pattern combining vertical and horizontal lines is recorded, and the measurement patterns of cyan, magenta, yellow, and black are represented as Pc, Pm, Py, and Pb. , Are recorded at positions on both ends corresponding to the pattern readers 19a and 19b.

FIG. 4 is a block diagram of the first embodiment of the present invention, and FIG.

In FIG. 4, the same components as those shown in FIGS. 1, 2 and 3 are denoted by the same symbols, and 22a and 22b are CCD control circuits (readout circuits). Line sensor 194
a, 194b for reading out the received light signal and outputting it as shown in FIG. 5, 23a and 23b are A / D (analog / digital) conversion circuits, which output the CCD line sensors 194a and 194b as shown in FIG. A / D conversion and output to the control unit 20 are indicated by 24a and 24b, which are driver circuits. The blue, green and red light emitting diodes 190a and 191a and 192a, 190b, 191b and 192b are instructed by the control unit 20. It is driven by.

The control unit 20 is a mechanical control unit that controls the recording units 10 to 13, is configured by a microprocessor (MPU), and stores a pattern memory 20a that stores the above-described measurement pattern data.
And an image memory 20b for storing cyan, magenta, yellow, and black read data.

The display unit 21 includes a display panel of the apparatus, and displays measured position information in addition to the state information of the apparatus.

FIG. 6 is a processing flowchart of the first embodiment of the present invention, and FIG. 7 is an explanatory diagram of the first embodiment of the present invention.

When an operator gives an instruction for a recording position adjustment mode from an operation panel (not shown), a control unit (hereinafter, referred to as an MPU) 20
Executes the recording position adjustment mode.

That is, the MPU 20 reads the measurement pattern from the pattern memory 20a, creates print data of each color, supplies it to the recording units 10 to 13 of each color, and prints a cross-shaped register mark as shown in FIG. Print each color on PP.

Then, the MPU 20 detects that the leading end of the recording paper PP has reached the pattern readers 19a and 19b with a sensor (not shown),
The process of FIG. 6 is started.

The MPU 20 turns on the red (R) light emitting diodes 192a and 192b for a certain period of time via the drivers 24a and 24b.

While the light emitting diode is on, the MPU 20 outputs the output of one line of the CCD line sensors 194a, 194b to the A / D converters 23a, 23
b, and stored in the cyan area of the image memory 20b as shown in FIG.

That is, since the cyan toner image favorably absorbs the light emitted from the red light emitting diode, the cyan toner image is read.

Next, the MPU 20 turns on the green (G) light emitting diodes 191a and 191b for a certain period of time via the drivers 24a and 24b.

The MPU 20 outputs the output of one line of the CCD line sensors 194a, 194b to the A / D converter 23a,
It is read from 23b and stored in the magenta area of the image memory 20b.

At this time, since the magenta toner image absorbs light emitted from the green light emitting diode well, the magenta toner image is read.

The MPU 20 turns on the blue (B) light emitting diodes 190a and 190b for a certain period of time via the drivers 24a and 24b.

The MPU 20 outputs the output of one line of the CCD line sensors 194a, 194b to the A / D converter 23a,
It is read from 23b and stored in the yellow area of the image memory 20b.

At this time, since the yellow toner image satisfactorily absorbs the light emitted from the blue light emitting diode, the yellow toner image is read.

Next, the MPU 20 turns on the red (R) light emitting diodes 192a and 192b for a certain period of time via the drivers 24a and 24b.

The MPU 20 outputs the output of one line of the CCD line sensors 194a, 194b to the A / D converter 23a,
The data is read from 23b and stored in the black area of the image memory 20b.

The black toner image absorbs any of the red, blue, and green light-emitting colors, and any color light-emitting diode may be used. Here, a red light-emitting diode is used.

Then, the MPU 20 increments the address of each color in the image memory 20b by the length α of one line.

Next, the MPU 20 determines whether or not the required number of lines (for example, 10 lines) has been captured, and if not, returns to the step.

When the MPU 20 determines that the required number of lines have been fetched, the image memory 20b stores left and right cross-shaped measurement patterns of cyan, magenta, yellow, and black as shown in FIG.

The MPU 20 calculates the coordinates Xc, Xm, Xy, Xb of the vertical line of the pattern from the area of each color in the image memory 20b (the capture area of the left sensor).
Is detected as shown in FIG.

Next, the MPU 20 detects the horizontal line coordinates Yc ₁ , Ym ₁ , Yy ₁ , and Yb ₁ of the left pattern of each color from the image memory 20b.

Similarly, the MPU 20 detects the horizontal line coordinates Yc ₂ , Ym ₂ , Yy ₂ , and Yb ₂ of the right pattern of each color from the image memory 20b.

Next, the MPU 20 calculates the differences Δc, Δm, Δy, Δb of the horizontal line coordinates of the left and right patterns of each color into (Yc ₁ −Yc ₂ ), (Ym ₁ −Ym ₂ ),
It is obtained from the calculation of (Yy ₁ −Yy ₂ ) and (Yb ₁ −Yb ₂ ).

Then, the MPU 20 calculates the inclination amounts Rc, Rm, Ry, Rb of the respective colors by using the measurement time interval Δt, Δc × Δt, Δm × Δt, Δy × Δt,
It is obtained by the calculation of Δb × Δt.

Next, the MUP 20 calculates a displacement in the main scanning direction. At this time, the shift of the other colors in the main scanning direction is calculated based on the cyan color.

That is, based on the vertical coordinate Xc of the cyan color detected in the step, the positional deviation Mm, M from the vertical coordinate Xm, Xy, Xb of each color.
y and Mb are calculated by the following equations.

Mm = Xm = Xc My = Xy−Xc Mb = Xb−Xc The MPU 20 compares the obtained inclination amounts Rc, Rm, Ry, and Rb with the maximum value of the inclination adjustment range, and if the amount exceeds the maximum value, an error (adjustment) is performed. Out of range).

Similarly, the MPU 20 calculates the positional deviation amounts Mm, M in the main scanning direction.
y and Mb are compared with the maximum value of the adjustment range of the positional deviation, and those exceeding the maximum value are determined as errors (out of the adjustment range).

Then, the MPU 20 displays the inclination amounts Rc, Rm, Ry, R
In the case of b and error, the error is regarded as the displacement M in the main scanning direction.
If the error is m, My, Mb, an error is displayed.

Looking at the positional deviation information displayed on the display unit 21 of the printer main body in this way, the adjuster operates the LED array 102 of FIG.
Adjust the position by operating the adjustment screw. If the error is displayed, replace the recording unit.

Therefore, the adjustment amount is determined by looking at the measured display result, the adjustment procedure is simplified, and the adjustment is easy.

Therefore, it is not necessary to perform adjustment at the time of assembling, and it is sufficient to perform adjustment after assembling the printer main body, so that the number of man-hours for assembly and adjustment can be reduced.

In addition, the adjustment after replacing the LED array head or the drum can be simplified, the downtime of the apparatus is shortened, and the maintenance service is improved.

By using the above-mentioned crosshair pattern as a measurement pattern, it is possible to measure not only inclination but also dot misalignment, which is convenient.

Moreover, the existing control unit 20 and display unit 21 in the printer main body can be used, and the increase in hardware can be minimized.

(C) Description of Second Embodiment FIG. 8 is an explanatory diagram of a pattern reader according to a second embodiment of the present invention.

In the figure, the same elements as those shown in FIG. 3 are indicated by the same symbols, 195 is a slit, which limits the reflected light from the recording paper PP, 196 is a photodiode,
It receives reflected light and converts it into an electric signal.

As shown in FIG. 3B, a pair of pattern readers 19a and 19b are provided at both ends of the recording paper PP.

On the other hand, on the recording paper PP, four linear patterns Pl ₁ and Pl _{2 of} cyan, magenta, yellow, and black are recorded at both ends, respectively, and patterns Pc, Pm, Py, P
b is recorded in each color to form a measurement pattern.

 FIG. 9 is a block diagram of a second embodiment of the present invention.

In the figure, the same components as those shown in FIGS.
Indicated by the same symbol, 25a and 25b are amplifiers (amplifier circuits)
And amplifies the light receiving signals from the photodiodes 196a and 196b, respectively, and outputs the amplified signals to the A / D converters 23a and 23b.

The control unit 20 has a pattern memory 20a storing the above-described measurement pattern data, and a time table 20c storing the measured time.

FIG. 10 is an explanatory diagram of the inclination amount measuring operation, FIG. 11 is an explanatory diagram of the deviation amount measuring operation in the main scanning direction, and FIGS. 12 and 13 are processing flowcharts of the second embodiment of the present invention.

When an operator gives an instruction for a recording position adjustment mode from an operation panel (not shown), a control unit (hereinafter, referred to as an MPU) 20
Executes the recording position adjustment mode.

That is, the MPU 20 reads the measurement pattern in the pattern memory 20a, creates print data of each color, and supplies the print data to the recording units 10 to 13 of each color. The horizontal line pattern shown in FIG. The line combination pattern is printed on the recording paper PP in each color.

Then, the MPU 20 detects that the leading end of the recording paper PP has reached the pattern readers 19a and 19b with a sensor (not shown),
The process of FIG. 12 starts.

The MPU 20 turns on the red (R) light emitting diodes 192a and 192b for a certain period of time via the drivers 24a and 24b.

While the light emitting diode is on, the MPU 20 reads the outputs of the photodiodes 196a and 196b from the A / D converters 23a and 23b, and calculates the cyan measurement time t _c of the time table 20c (t _c
+1), and checks whether the output of the read photodiodes (sensors) 196a and 196b is at a high level ("1").

If not high level, linear pattern as shown in Fig. 10
Pl _c1, because not detected (Pl _c2), light emitting diodes 192
It returns to lighting of a, 192b.

Meanwhile, MPU 20 includes a photodiode 196a, if the output of 196b is high level, linear pattern as FIG. 10 Pl _c1 (Pl
It detected a _c2), to save the cyan measurement time t _c.

Next, the MPU turns on the green (G) light emitting diodes 191a and 191b via the drivers 24a and 24b for a certain period of time, and while the lights are on, outputs the outputs of the photodiodes 196a and 196b to the A / D converters 23a and 23b. reading from 23b, it increments the magenta for measuring time t _m of the timetable 20c to (t _m +1).

Then, the MPU 20 reads the photodiodes 196a and 196
b outputs are examined or high level, if not at a high level, the light emitting diodes 191a, return to the lighting of 191b, if a high level, to save the magenta measurement time t _m.

Next, the MPU 20 turns blue (B) through the drivers 24a and 24b.
The light emitting diodes 190a and 190b are turned on for a certain period of time. While the light emitting diodes 190a and 190b are turned on, the outputs of the photodiodes 196a and 196b are read from the A / D converters 23a and 23b, and the yellow measurement time t _y of the time table 20c is set to ( Increment to t _y +1).

Then, the MPU 20 reads the photodiodes 196a and 196
b outputs are examined or high level, if not at a high level, the light emitting diodes 190a, return to the lighting of 190b, if a high level, saves the yellow measurement time t _y.

In addition, the MUP20 is red (R) via drivers 24a and 24b.
Light emitting diodes 192a, a certain time lights 192b, while illuminated photodiode 196a, outputs the A / D converter 23a of 196b, read from 23b, the black for measuring time t _b timetable 20c ( Increment to t _b +1).

Then, the MPU 20 reads the photodiodes 196a and 196
b outputs are examined or high level, if not at a high level, the light emitting diodes 192a, return to the lighting of 192b, if a high level, to save the black measurement time t _b.

In this way, the left and right reader 19a, at 19b, the color of a horizontal line pattern _{Pl c (Pl c1, Pl c2} ), Pl m (Pl m1, Pl m2), Pl y (P
_{l y1, Pl y2), Pl} b (Pl b1, Pl b2) until the measurement time t _c (t _c1, t
_c2 ), t _m (t _m1 , t _m2 ), t _y (t _y1 , t _y2 ), and t _b (t _b1 , t _b2 ) were measured.

The MPU 20 turns on the red (R) light emitting diode 192a via the driver 24a for a certain period of time, and reads the output of the photodiode 196a from the A / D converter 23a while the light emitting diode 192a is turned on.

The MPU 20 checks whether the read output level is “1”,
If it is "1", as shown in FIG. 11, the time table 20c
The measurement time _Tc for cyan is incremented to ( _Tc + 1), and the operation returns to the lighting of the light emitting diode 192a.

Conversely, if the output level is not "1", it is checked whether the output level is "2". If not, the light emitting diode 192a is turned on again. The cyan measurement time _Tc is saved as shown in FIG.

Next, the MPU 20 turns on the green (G) light emitting diode 191a through the driver 24a for a certain period of time, and reads the output of the photodiode 196a from the A / D converter 23a while the light emitting diode 191a is turned on.

The MPU 20 checks whether the read output level is “1”,
If it is "1", as shown in FIG. 11, the time table 20c
Increments of the magenta measurement time T _m to (T _m +1), returns to the lighting of the light emitting diode 191a.

Conversely, if the output level is not "1", it is checked whether the output level is "2". If the output level is not "2", the light emitting diode 191a is turned on again. as, to save the magenta for the measurement time T _m of.

Next, the MPU 20 turns on the blue (B) light emitting diode 190a via the driver 24a for a certain period of time, and reads the output of the photodiode 196a from the A / D converter 23a while the light emitting diode 190a is turned on.

The MPU 20 checks whether the read output level is “1”,
If it is "1", as shown in FIG. 11, the time table 20c
Incrementing the yellow measurement time T _y to (T _y +1), returns to the lighting of the light emitting diode 190a.

Conversely, if the output level is not "1", it is checked whether the output level is "2". If the output level is not "2", the light emitting diode 190a returns to lighting. to save the yellow for the measurement time T _y as.

Further, the MPU 20 turns on the red (R) light emitting diode 192a for a certain period of time via the driver 24a, and reads the output of the photodiode 196a from the A / D converter 23a while the light emitting diode 192a is turned on.

The MPU 20 checks whether the read output level is “1”,
If it is "1", as shown in FIG. 11, the time table 20c
Incrementing black for measurement time T _b to (T _b +1), returns to the lighting of the light emitting diode 192a.

Conversely, if the output level is not "1", it is checked whether the output level is "2". If not, the light emitting diode 192a is turned on again. to save the black for the measurement time T _b and so on.

In this manner, each color of the pattern _{P c, P m, P y} , P b of the horizontal line and the oblique line interval the time interval T _c of, T _m, T _y, measured at T _b.

Next, the MPU 20 calculates the times t _c1 , t _c2 , t _m1 , t _m2 , t _y1 , t _y2 , t _b1 and t _{b2 of} the left and right horizontal line patterns measured as shown in FIG.
From the following equation, the time difference Δc, Δm, Δy, Δ
Find b.

_{Δc = t c1 -t c2 Δm =} t m1 -t m2 Δy = t y1 -t y2 Δb = t b1 -t b2 Then, MPU 20 uses the measured time interval Delta] t, the following equation, the color of the inclination amount R _{Find c} , R _m , R _y , and R _b .

_{R c = Δc × Δt R m} = Δm × Δt R y = Δy × Δt R b = Δb × Δt Then, MPU 20 is shifted M _c in the main scanning direction of each _{color, M m, M y, M} b the reference time It is calculated using the interval ΔT.

It _{M c = T c -ΔT M m} = T m -ΔT M y = T y -ΔT M b = T b -ΔT M c ~M b is negative, that the recording pattern is shifted to the right , Positive indicates that the recording pattern is shifted to the left.

The MPU 20 compares the obtained inclination amounts R _c , R _m , R _y , and R _b with the maximum value of the inclination adjustment range, and determines that the error exceeds the maximum value as an error (out of the adjustment range).

Similarly, the MPU 20 _calculates the position shift amounts M _c , M
_m, compared M _y, and the maximum value of the positional deviation adjustment range M _b, which exceeds the maximum value is determined as an error.

Then, the MPU 20 displays the inclination amounts R _c , R _m , R _y , R
_In the case of _b and error, the error is regarded as the displacement M in the main scanning direction.
_c, M _m, M _y, in the case of M _b and error display an error.

Adjustment of the LED array 102 is performed in the same manner as in the first embodiment.

(D) Description of Other Embodiments In addition to the above-described embodiments, the following modifications are possible in the present invention.

In the above embodiment, an example of manual adjustment has been described. However, by providing a head moving mechanism in the LED head,
Automatic adjustment is also possible.

Although the display unit is also used as the one in the printer device such as the CE panel and the operator panel, a separate display for measurement may be provided and displayed by connecting to the device.

Although the pattern reader has been described with the light emitting units of the three primary colors and the CCD line sensor or photosensor, it may be constituted by one light emitting unit of white light and three light receiving units provided with filters of each color.

Although the configuration in which the pattern reading unit is disposed between the fixing device and the stacker has been described, the pattern reading unit may be disposed in front of the fixing device, that is, at a position where the positional deviation of the unfixed toner image is measured.

In this case, heat is applied to the recording paper by the fixing device, so that error factors such as contraction of the recording paper can be reduced.

However, since the surface is not fixed and irregular reflection on the surface of the toner image increases, care must be taken in setting the detection level.

The recording unit has been described as four electrophotographic units, but it is also possible to use a four-color exposure unit and developing unit on one photosensitive drum to perform transfer in one transfer, and the exposure part is also limited to an LED array Instead, a laser optical system, a liquid crystal shutter system, or the like may be used.

Although an electrophotographic method has been described, other recording methods such as a transfer electrostatic recording method, a thermal transfer recording method, and an ink jet recording method can be used.

Further, the amount of displacement in the sub-scanning direction may be measured by using a measurement pattern.

Although the present invention has been described with reference to the embodiments, the present invention can be variously modified in accordance with the gist of the present invention, and these are not excluded from the present invention.

〔The invention's effect〕

As described above, the present invention has the following effects.

By providing a pattern reader and control means,
The displacement amount of the recording unit can be automatically measured from the recording paper on which the measurement pattern is printed, and can be measured in a short time because no manual operation is required.

Since the measurement is not performed manually, the measurement can be performed accurately and the adjustment can be easily performed.

Since no manpower is required, non-skilled persons can easily make adjustments, and adjustments can be made in the field.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention, FIG. 2 is a block diagram of a color printing apparatus according to an embodiment of the present invention, FIG. 3 is an explanatory diagram of a pattern reader according to the first embodiment of the present invention, and FIG. FIG. 5 is a block diagram for explaining a reading operation in FIG. 4, FIG. 6 is a processing flowchart of the first embodiment of the present invention, and FIG. 7 is a first embodiment of the present invention. FIG. 8 is an explanatory view of a pattern reader according to a second embodiment of the present invention, FIG. 9 is a block diagram of a second embodiment of the present invention, and FIG. 10 is a second embodiment of the present invention. FIG. 11 is an explanatory diagram of a tilt amount measuring operation of the embodiment, FIG. 11 is an explanatory diagram of a main scanning direction shift measuring operation of the second embodiment of the present invention, and FIGS. 12 and 13 are processing flows of the second embodiment of the present invention. FIG. In the figure, 10 to 13: recording unit, 19: pattern reader, 20: control means, PP: recording body.

Continuing from the front page (72) Inventor Toshio Hunaka 1015 Uedanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Tomohisa Mikami 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (58 ) Surveyed field (Int.Cl. ⁶ , DB name) G01B 11/00

Claims (12)

(57) [Claims] A color printing apparatus for performing color printing on a recording medium (PP) by a plurality of recording units (10 to 13) having different recording colors, wherein a pattern for reading a recording pattern of each color of the recording medium (PP) is provided. A reading device (19) is provided, a measurement pattern is recorded in each recording color by the plurality of recording units (10 to 13) on the recording material (PP), and the recording material (PP) is recorded by the pattern reader (19). 3.) A method for measuring the displacement of a color printing device, comprising: reading a measurement pattern of each color above; measuring a position of the read measurement pattern of each color by a control means (20) to obtain measurement position information. 2. The method according to claim 1, wherein the measurement position information is displayed by a display means. 3. The recording position information of each recording unit (10
The method for measuring a displacement of a color printing apparatus according to claim 1, wherein the recording inclination amount and the displacement amount in the main scanning direction of (13) to (13). 4. The method according to claim 3, wherein the measurement pattern is a pattern obtained by combining a horizontal line and a vertical line. 5. The method according to claim 3, wherein the measurement pattern is a combination of a horizontal line and an oblique line. 6. The recording means according to claim 1, wherein said control means causes said recording unit to record said measurement pattern in response to a recording position adjustment mode instruction. 10. A method for measuring a position shift of a color printing apparatus according to claim 1. 7. A color printing apparatus for performing color printing on a recording medium (PP) by using a plurality of recording units (10 to 13) each having a different recording color. 13), a control means (20) for recording a measurement pattern in each recording color and a pattern reader (19) for reading the measurement pattern of each color on the recording medium (PP) are provided. ) Measures the position of the measurement pattern of each color read, and obtains measurement position information. 8. A display means (2) for displaying the measurement position information.
The displacement measuring device for a color printing device according to claim 7, wherein 1) is provided. 9. An apparatus according to claim 8, wherein said display means is provided in said color printing apparatus. 10. The recording means according to claim 7, wherein said control means causes said recording units to record said measurement pattern in response to a recording position adjustment mode instruction. Of color misalignment of color printing equipment. 11. The apparatus according to claim 7, wherein said pattern reader is a light emitting diode of three primary colors and a CCD line sensor. 12. The apparatus according to claim 7, wherein said pattern reader is a light emitting diode of three primary colors, a slit, and an optical sensor.