JP2002337327A - Recording position reader, recording position reading method, and recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording position correcting method, an ink jet recorder and an ink jet recording method in which a recording position can be corrected accurately with no error even if the distance between a sensor and the plane of a recording sheet varies due to floating of the plane of the recording sheet. SOLUTION: When the same pattern (801) is read out by a plurality of sensors (sensor A, sensor B) having a different read angle, floating state of a recording sheet recording a pattern can be calculated as the sheet floating amounts (h1, h2) at the opposite ends of the pattern. Since a sheet floating error included in data read out by means of the sensors can be removed based on the sheet floating amounts, the recording position can be corrected (correction of registration shift) accurately at all times with no error.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a recording position correcting device,
More particularly, the present invention relates to a recording position correction method and a recording apparatus, and more particularly to reading a pattern for correcting a recording timing of a recording head.

[0002]

2. Description of the Related Art FIG. 1 shows an example of a main part relating to an ink jet type color recording. When printing on the printing paper 105 on the platen 106, the motor 103 is driven first, and the main scanning carriage 102 is moved by the drive belt 109 to the position of the home position sensor 108. Next, the carriage 102 is caused to scan in the forward direction in the direction of arrow A, and plaques Bk, cyan C, magenta M, and yellow Y are respectively printed from predetermined positions on the recording heads 120, 121, and 121.
Discharge from 122 and 123. As a result, an image for one printing scan is printed. After the printing scan for a predetermined distance is completed, the main scanning carriage 102 is temporarily stopped, and then backwardly scanned in the direction of arrow B to return to the position of the home position sensor 108. During the backward scan, the paper feed roller 101 is driven by the paper feed motor 107, and the paper is fed in the direction of arrow C by the width recorded in the preceding forward scan. By repeating the forward scan, the backward scan, and the paper feed scan, a color image is sequentially recorded on the recording paper 105. Note that reference numeral 100 denotes a second paper feed roller, and 111 denotes a paper detection sensor.

In order to perform color image recording, recording heads 120, 121, and 12 are used for the same pixel.
The black Bk, cyan C, magenta M, and yellow Y inks ejected from the printers 2 and 123 need to be accurately overlapped or recorded at an appropriate position. However, for example, when the recording heads 120 to 123 are replaced or the like, the mounting position on the main scanning carriage 102 shifts, and the dots of each ink on the paper surface do not overlap or the dots are not formed at the correct positions. In this case, the dots of the respective color inks are shifted from each other (hereinafter also referred to as registration shift). In this state, desired recording quality cannot be obtained.

As a solution to this problem, the following method has already been proposed and implemented. FIG. 2 shows chart patterns 130 to 133 for detecting a registration shift, and an output result 134 of a signal value obtained by reading these with a sensor or the like. The four chart patterns 130 are black heads 120
Reference numeral 131 denotes a cyan head 121, 132 denotes a magenta head 122, and 133 denotes a yellow head 123. Each pattern is arranged with a predetermined number of pixels. For example, when a sensor is mounted on the carriage 102 of FIG. 1 and the carriage is scanned at a constant speed while detecting the chart pattern in a direction perpendicular to the paper surface, an output result as shown in an output waveform 134 of the pattern is obtained. Can be

Hereinafter, a pattern reading method and a correction method in a conventional example when the registration is actually shifted will be specifically described.

First, from the sensor output signal 134, the time until the fall and the rise are obtained as T1 to T4, respectively. Further, difference times t1 to t3 between adjacent different color patterns are obtained from the respective intermediate times. Normally, the distance between the patches is set to a predetermined value (the number of pixels), so that t1 to t3 should obtain predetermined correct values, respectively. However, as described above, when the intervals between the heads vary when the heads are attached, the recording interval between the patches also shifts. As a result, t1 to t3 are also detected with deviation from a predetermined value.

From the values of t1 to t3 obtained above and the carriage speed at the time of detection, the recording interval of each pattern on the paper can be obtained. The amount of registration deviation (distance) on the recording paper can be determined from the difference between this value and the correct recording interval that should be obtained.

Although the above-mentioned t1 to t3 have been described in units of time, the count value of the encoder during each of t1 to t3 may be used as an actual measurement value. In this case, the absolute position between each patch can be measured without considering the carriage speed.

According to the above-described method, if the amount of misregistration for each color on the paper is known in advance, the ejection timings of the heads 120 to 123 corresponding to each color are shifted from each other so that the dots of each color are controlled to overlap the same position. Then, it is possible to set the registration error to zero.

According to the above-described method, even if the positions of the heads of the respective colors are shifted when the heads are mounted, it is possible to correct the misregistration of the dots of the respective inks on the paper surface and obtain a desired recording quality. Was.

[0011]

However, while the registration adjustment generally requires an accuracy on the order of several microns, the registration adjustment method may not provide sufficient accuracy. The main cause is that unevenness or inclination occurs on the paper surface, and the distance between the surface on which the chart pattern is recorded and the sensor for detecting registration deviation is not always kept constant.
In this case, a large error is included in the measured registration deviation amount, and accurate correction cannot be performed.

The above phenomenon will be specifically described with reference to FIG. For example, the Bk pattern 130 and the C pattern 1 in FIG.
It is assumed that the paper floats at the position 31 and the distance from the sensor is shorter than the other two-color patterns. In this case, C
That is, at least the inclination of the paper surface is generated between the patterns M and M. However, since the sensor does not follow the inclination of the page and is always scanned parallel to the platen, C and M
Is detected to be shorter than the actual distance on the paper. The distance shorter than the actual distance is detected as t2. If correction is made based on this, two colors Bk and C and two colors M and Y will be recorded at positions shifted from each other.

The factors that prevent the distance between the sheet and the sensor from being kept constant include the following. The first major factor is that the pressure applied to the paper at the recording position does not become uniform on the recording paper, and the amount of floating of the paper at each position on the paper greatly varies. Also, once the chart pattern is recorded on the paper, and once the recording paper is rewound,
In some cases, the paper floats by about several tens of μm during the process of measuring the pattern again with the sensor for detecting the registration deviation. Further, depending on the type of the recording paper, the ink is absorbed by recording the chart pattern, and the fibers expand and contract again, so that the recording surface on the paper surface may rise to unevenness.

As described above, the paper has irregularities and inclinations,
If the relationship parallel to the scanning direction of the sensor cannot be maintained, the distance between the read patterns and the correction amount obtained by calculation include a large error. Therefore, even if registration deviation correction is performed using that value, correct correction cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and an object of the present invention is to include an error even when the distance between the sensor and the recording paper varies due to the floating of the recording paper. It is an object of the present invention to provide a recording position correction method, an ink jet recording apparatus, and an ink jet recording method capable of correcting the recording position accurately.

[0016]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a plurality of recording position detection units which have different reading angles from each other and detect the recording position of a pattern recorded on a recording medium. Means, calculating means for calculating the amount of paper floating of the recording medium based on detection data from the plurality of recording position detecting means, and a pattern detected by the recording position detecting means based on the amount of paper floating of the recording medium. And a correction means for correcting the recording position to obtain a corrected recording position.

Further, a pattern recorded on a recording medium is detected by a plurality of recording position detecting means having reading angles different from each other, and the detection data from the plurality of recording position detecting means detects a pattern on the recording medium. A step of calculating an amount and correcting a recording position of the pattern detected by the recording position detecting means based on a floating amount of the recording medium to obtain a corrected recording position.

Further, in a recording apparatus which performs recording on a recording medium by using a plurality of recording heads, each of the plurality of recording heads is connected to the recording medium by using a plurality of recording position detecting means having different reading angles. Based on the detection data obtained by detecting the recording positions of the plurality of recorded patterns, an arithmetic unit that calculates the paper floating amount of each of the plurality of patterns, and the recording position detection unit that is detected based on the respective paper floating amounts. Correction means for correcting the recording positions of the plurality of patterns to obtain a corrected recording position, and recording timing correction means for correcting the recording timings of the plurality of recording heads based on the corrected recording positions by the correction means. And

According to the above arrangement, when a plurality of sensors having different reading angles read the same pattern in a case where the recording paper after the pattern recording has a non-uniform paper floating, the detection data becomes the reading angle. And a phase shift corresponding to the paper floating amount. Therefore, based on the phase shift, it is possible to obtain the correction detection position data from which the paper floating error of the recording paper has been removed, and it is possible to obtain the recording position correction data that does not include the error.

[0020]

FIG. 3 is a block diagram showing the configuration of an ink jet recording apparatus according to an embodiment of the present invention.
Reference numeral 10 denotes a control unit that controls the entire recording apparatus.
Reference numeral 1 denotes a recording position detection unit for identifying the recorded registration misalignment pattern.

The recording position detecting section 11 is mounted on a carriage of a mechanical drive section 13, and this carriage is connected to the carriage shown in FIG.
102. The recording position detection unit 11 includes a light source that irradiates light by switching filters of a plurality of colors, and a plurality of sensors for receiving reflected light on the paper surface. The multi-color filters can identify each color pattern of black Bk, cyan C, magenta M, and yellow Y.
It is composed of red R, green G, and blue B that emit respective complementary colors. The plurality of sensors are attached to the carriage 102 so that the viewing angles are different from each other in the direction perpendicular to the paper. The output from each sensor is
The signal is amplified by an amplifier circuit (not shown), compared with a reference signal by a comparator, and converted into a digital signal of 0.5V. The digitized signal and the signal inverted by the inverter circuit are connected to an interrupt terminal of an MPU (microprocessor) in the control unit 10,
Thereby, the control unit 10 can detect the rising and falling timings of the sensor output signal in real time.

The mechanical drive unit 13 has the same configuration as that of FIG. 1 used in the description of the conventional example, and includes a carriage unit and a carriage drive unit for moving the recording head in the main scanning direction.
It comprises a paper feed unit for recording paper, a paper transport unit, a paper discharge unit, and a recovery unit unit for recovering from clogging of the recording head with ink.

Reference numeral 12 denotes an operation panel including switches for paper feed, paper discharge, paper selection and the like, and a display system for displaying the status of the ink jet recording apparatus. Is performed.

Reference numeral 14 denotes an I / F unit, which is connected to a host computer (not shown). A command and print data are sent from the host computer, and the inkjet printing apparatus operates according to the command to print the print data. Generally, Centronics and SCSI interfaces are often used as the I / F unit 14.

Reference numeral 15 denotes a memory controller which transfers a command input from the I / F unit 14 to the control unit 10, and under the control of the control unit 10, writes an address and a write command so that recording data is written to the memory unit 16. Generate a timing signal. The command input from the I / F unit 14 is interpreted by the control unit 10, and the control unit 10 controls the entire inkjet recording apparatus.

The memory section 16 is composed of one or more bands of memory required for the recording head to scan once in the main scanning direction and perform recording. If the number of nozzles in the sub-scanning direction of the print head is 128 nozzles and the maximum number of dots that can be printed in one scan is 8 k dots, 128 (nozzle) × 8 k (dots) × 4 (color) = 4 MB
It has a memory capacity of it.

Further, the memory controller 15 and the memory unit 16 independently store the special pattern data such as the register detection pattern by the control unit 10 in the memory unit 1.
6 can be generated. In this case, there is no need to transfer data from the host computer.

Reference numeral 17 denotes a head controller, which controls the head unit 18 according to an instruction from the control unit 10.

The head section 18 is attached to the carriage section of the mechanical drive section 13 and comprises a recording head for each color ink.

Numeral 19 is a nonvolatile memory for storing data.
The control unit 10 stores correction data and the like after registration error detection performed at the time of head replacement.

When the registration adjustment is actually performed, the control unit 1
0 causes the memory 16 to generate a special pattern for register detection, and causes the head unit to record the pattern shown in FIG. 2 via the head controller. After that, the control unit 10 causes the mechanical drive unit to perform the paper feed scanning until the recording position detection unit 11 can detect the recorded pattern. Further, the carriage 102 is caused to scan by the mechanical drive unit, and during that time, the recording position detection unit attached to the carriage 102
The control unit 10 calculates the registration correction value of each color by detecting the distance of each pattern. The calculated value is stored in the data storage nonvolatile memory 19 as a correction value. Thereafter, when recording is actually performed, correction is always performed with reference to the correction value stored in 19.

Next, the principle of the processing method of the present invention will be described with reference to FIGS. FIGS. 7A and 7B are diagrams showing an example when there is no paper floating, and the sensors A and B each have a pattern 601 for one color on the recording paper.
Are mounted on the carriage with inclinations of θ1 and θ2. Here, for convenience of explanation, two sensors are used, but the present embodiment and the invention are not limited to this. As the installation position and the number thereof increase, the target correction accuracy for paper floating increases.

In FIG. 7A, each sensor receives scattered light on the paper surface in a parallel visual field region. The diameter of the light receiving surface of each sensor is 2R, and the distance to the recording paper is X. Further, the width of the pattern 601 recorded on the paper is represented by Y.

When the carriage is moved along the plane of the paper,
Each sensor output signal shown in FIG. 7B is obtained. The horizontal axis indicates the detection position, and the vertical axis indicates the output value. The actual pattern recording start position is P, and the address values (encoder count values) indicating the edge timings obtained from the sensor signal values are the start positions As, Bs, and the end positions Ae, respectively.
Assuming Be, As = P−X × TAN (θ1) −R / COS (θ1) Bs = P + X × TAN (θ2) −R / COS (θ2) Ae = P + Y−X × TAN (θ1) −R / COS (Θ1) Be = P + Y + X × TAN (θ2) −R / COS (θ2). . . (1) This is the value when there is no paper floating.

FIG. 8 is an explanatory diagram of a case where the paper is uniformly raised. In the drawing, reference numeral 701 denotes one color of a registration misregistration detection pattern recorded on the paper surface, which is closer to the sensors A and B by Z, the amount of paper floating. In this case, the signal obtained from the sensor A is delayed by △ A1 as compared with the case where the paper is not lifted, and the signal obtained from the sensor B is △ B
Advance by one. This relationship can be expressed by the following equation: A1 = Z × TAN (θ1) ΔB1 = Z × TAN (θ2) As2 = As + Z × TAN (θ1) Bs2 = Bs−Z × TAN (θ2) Ae2 = Ae + Z × TAN (θ1) Be2 = Be−Z × TAN (θ2)

Here, each of As2, Ae2, Bs2, Be
2 is an address value indicating the edge timing of each signal as in FIG. As described above, the length of the signal corresponding to the recording pattern 701 of the two sensors A and B (when the signal in the drawing is at a low level) is larger when the paper is uniformly raised than when the paper is not raised. ) Is the same, but it can be seen that the phase of each output signal is shifted back and forth. Then, the paper floating amount Z can be calculated backward from this deviation amount.

FIGS. 9 and 10 are illustrations of a general paper floating case. FIG. 9A shows a state in which the paper surface gradually lowers to the right while changing the inclination.
Reference numeral 1 denotes a one-color recording pattern at this time. FIG. 9B shows an output signal having such a gradient. The width of the low-level output signal obtained from each sensor (WA2, W
B2) is when there is no paper floating (WA1 and WB1 in the figure)
It is shorter than. This is because the area (width) that can be detected by the sensor is reduced due to the influence of the paper being uneven and floating on unevenness. Therefore, the measured value (WA
2, WB2) and when there is no paper floating (WA1, WB1)
By calculating the difference from the above, it is possible to detect that the paper has an inclination or unevenness. When the following expression is satisfied, it can be determined that the paper is floating in a state where the paper is lowered to the right. WA2 / WA1 <WB2 / WB1 FIG. 9 is a model diagram for obtaining the amount of paper floating and the position of the recording pattern in a state where the presence / absence and direction of the inclination are detected.
It is shown in (c). In the figure, X is the distance from the sensor to the paper surface, and p1 and p2 are the start and end points of the recording pattern projected on the assumed paper surface p1ane1.
Since the irregularities between p1 and p2 do not directly affect the registration deviation, they are connected here by a straight line. FIG.
Sensors A and B corresponding to the recording pattern shown in (b)
Points on p1ane1 corresponding to output timings As3, Ae3, Bs3, Be3 of as3, ae3,
bs3, be3, h1 represents the amount of paper floating at the recording start point of the recording pattern, and h represents the amount of paper floating at the recording end point of the recording pattern.
When expressed as 2, as3 = p1 + h1 × TAN (θ1) ae3 = p2 + h2 × TAN (θ1) bs3 = p1-h1 × TAN (θ2) be3 = p2-h2 × TAN (θ2) From the above equation, h1 = (as3-bs3) / (TAN (θ1) 10 TAN
(Θ2)) h2 = (ae3-be3) / (TAN (θ1) 10 TAN
(Θ2)) p1 = (as3 × TAN (θ2) + bs3 × TAN (θ
1))) / (TAN (θ1) + TAN (θ2)) p2 = (ae3 * TAN (θ2) + be3 * TAN (θ
1))) / (TAN (θ1) + TAN (θ2)) Also, as3, ae3, bs3, and be3 are measured values obtained from the respective sensor outputs, As3, Ae3,
It is obtained from Bs3 and Be3 according to the above (1) as follows: as3 = As3 + X × TAN (θ1) + R / COS (θ
1) ae3 = Ae3 + X × TAN (θ1) + R / COS (θ
1) bs3 = Bs3-X × TAN (θ2) + R / COS (θ
2) be3 = Be3-X × TAN (θ2) + R / COS (θ
2) The paper floating amounts h1 and h2 and the recording pattern position p
1, p2 can be obtained.

As described above, the paper floating amounts h1, h2 and the recording pattern positions p1, p2 are obtained, and the recording pattern positions p1, p2 are determined.
With respect to p2, by performing the correction operation for the paper floating amount, the registration deviation amount in which the paper floating amount is canceled can be calculated.

On the other hand, FIG. 10 shows a state in which the paper surface is inclined downward to the right, and reference numeral 901 denotes a recording pattern for one color at this time. Also in this case, it is possible to detect whether the paper is smooth or floating by calculating the difference between the actually measured values (WA3, WB3) and (WA1, WB1) of the low-level signal output width. Also, contrary to the case of FIG. 9, it can be seen that paper floating occurs in a state of rising rightward from the satisfaction of the following equation. WA
3 / WA1> WB3 / WB1 As can be seen from FIG.
In contrast to the case of FIG. 9, when the paper is tilted and floated, the ratio of the low-level signal output time of ぺ 2 sensor outputs is reversed compared to the state where the paper is not lifted. Also in this case, as3, ae3, bs3, and be3 of the above equations are replaced with as4, a as in FIG.
The paper floating amounts h1 and h2 can be obtained by the arithmetic expressions replaced with e4, bs4 and be4.

Next, the actual operation of measuring the amount of misregistration of each head will be described with reference to the block diagrams of FIGS. 3, 4 and 5, and FIG. FIGS. 4 and 5 are flowcharts showing a measurement operation when register adjustment is performed, and FIG. 6 is a diagram showing a recording and reading state of a test pattern of each color in the present embodiment.

The ink jet recording apparatus of this embodiment is shown in FIG.
When the head section 18 detects that the head has been replaced, the operation of measuring the registration deviation amount is started (S300).

First, the control unit 10 controls the memory controller 1
5 is stored in the memory unit 16 at 500 to 50 in FIG.
A pattern for detecting a registration shift shown in FIG. 3 is generated and recording is performed (S301).

Next, the counters N and M indicating the number of times of registration detection are cleared (S302), and the carriage is moved to the home position (standby position before the start of recording) by driving the mechanical drive unit 13 (S303).

Then, the filter of the recording position detecting unit 11 is switched according to the registration detection counter N, and the light emitting element emits light (S304). Each counter corresponds to each of the following filters. N = 0: red, 1: green, 2: blue Such a filter switching is performed by irradiating complementary color light of each ink color to amplify the sensitivity of the light receiving unit for reading the recorded registration misregistration detection pattern of each color. Do to do. That is, when N is 0, the cyan component, which is the complementary color of red,
In the case of 1, the magenta component which is a complementary color of green is read, and in the case of 2, the yellow component which is a complementary color of blue is read. Further, since the black ink contains a cyan component, a magenta component, and a yellow component equally, it is possible to receive light using any filter.

Next, interrupt signals A and B of the MPU (microprocessor) in the control unit 10 which are generated in synchronization with the falling and rising of the sensor signal from the recording position detecting unit 11 are permitted (S305). Then, the mechanical drive unit 13 is driven in this permission state, and the carriage is driven in the forward direction in the direction indicated by the dotted line 504 in FIG. 6 (S306).

The detection processing of the actual registration error detection pattern thereafter is performed by interrupt processing, and the apparatus enters a standby state until the detection of the pattern is completed by the interrupt processing (S30).
7).

Sensors A, 505, and 506 in FIG. 6 when the carriage scans with the light emitting element emitting red light.
4 shows an example of an output signal waveform of B.

FIGS. 5A and 5B show the flow of an interrupt process which occurs in synchronization with the rise and fall of the sensor signals A and B, respectively.

As for the sensor A output signal, an interrupt A is generated (S400), and the encoder value indicating the carriage position at the time of the occurrence of the interrupt is used as a pattern position as AEnc.
[N] and stored in [M1] (S401). Then, the value of the counter M1 is incremented by 1 (S402). If the value of M1 is not 4, since the detection has not been completed, the next interrupt factor edge is switched (S405). M
If 1 is 4, the measurement of one set of black and another color has been completed, so the pattern detection ends and interrupt A is prohibited (S404). Then, the interrupt processing is completed (S40).
6) Wait for the next interrupt. As a result, a falling edge and a rising edge of the sensor output signal are generated alternately, and the encoder position is stored.

The same applies to the sensor B output signal.
An interrupt B occurs at each falling edge and rising edge (S410), and the encoder position data is stored in BEnc.
It is stored in [N] [M2] (S411). Next, the counter M2 is incremented by one (S413), and the measurement process is repeated until four interrupts occur and the measurement is completed (S413, S415, S414, S41).
6).

When the detection of the pattern is completed by the interrupt processing A and B (S307), the value of the registration detection counter N is incremented by one, and the registration detection counter M1,
M2 is cleared (S308). If the registration detection counter N is not 3, registration detection of the heads for all the colors has not been completed (S309).
Step 9 is repeated. When the registration detection counter N becomes 3, the detection of the registration deviation pattern for the heads for the four colors ends, and the positional information on the outputs of the sensors A and B corresponding to the registration deviation detection pattern in FIG. Each AE
nc and BEnc are stored on a two-dimensional array.

Next, from the encoder position information of the sensor A and B output signals corresponding to each of the obtained patterns, the paper floating amount of each of the patterns is calculated by the above-described arithmetic processing (S310).

FIG. 6B is a schematic view of each recording pattern on the paper as viewed from the side. In the figure, 510, 511, 5
Reference numerals 12 and 513 denote respective patterns of black Bk, cyan C, magenta M, and yellow Y, and each pattern is inclined due to unevenness of the paper surface. The center-to-center distance of each pattern obtained directly from the sensor is 514,5
15,516 (x1, x2, x3), which is a distance measured in the moving scanning direction of the sensor and is different from 517, 518, 519, which is an actual distance including irregularities on the paper surface. .

Distances 517, 518, 519 on paper
Can be obtained by using the calculation method for calculating the floating amount and the recording position described with reference to FIGS. The length of each straight line forming the polygonal lines 517, 518, 519 is obtained from the floating amount of each pattern. Then, as the sum of the straight lines, the actual distances 517, 518, and 519 between the center of each
Ask for. The distance between each color and Bk is determined in the present embodiment based on the recording position of the Bk dot, and the other three colors are adjusted to match this Bk position.

Next, a difference between 517, 518, and 519 and the distance between the recording patterns assumed from the recording data (the distance between the patterns to be recorded when there is no registration error) is obtained. This value is a regular registration deviation amount of each head, that is, a correction amount corresponding to an attachment position error between the heads (S
310).

In this embodiment, in order to correct the registration error, the output timing from the encoder is used, and the correction unit is a dot (recording pixel) unit. Therefore, the correction amount obtained above is converted into a deviation amount in encoder units (311), and the value is stored in the nonvolatile memory 19 for each ink color (S312).

Thereafter, when the power is turned on, the control unit 10
The value stored in 9 is read. When printing is actually performed, printing is performed with the drive timing of each color head corrected by shifting the print data read address from the band memory corresponding to each color by the correction amount.

As described above, according to the present embodiment, it is possible to adjust the registration of each color in the main scanning direction even when the paper floats.

The method for measuring the amount of registration deviation in the carriage scanning direction has been described above. In this case, since it is necessary to consider the paper surface irregularities in the carriage main scanning direction, the plurality of sensors need to have different reading angles in a plane perpendicular to the paper surface and including the carriage main scanning direction. However, the present invention is not limited to this.
Using the same principle configuration, the amount of registration deviation between heads in the paper feed direction can also be measured. In this case, since it is necessary to consider the influence of the unevenness in the paper feeding direction, the plurality of sensors may have different reading angles in a plane perpendicular to the paper surface and including the paper feeding direction. Of course, if the two sensors of the above-described embodiment have different reading angles not only in the carriage scanning direction component but also in the paper feeding direction component, two types of registration adjustment can be performed by the same sensor. . Even if more sensors are installed at various angles with respect to the component perpendicular to the paper surface, the same effect can be obtained and the correction accuracy can be increased.

In the present embodiment, the method of adjusting other colors with respect to black has been described. However, the same effect can be obtained by actually adjusting any color as a reference color with the difference.

Further, in the present embodiment, the registration adjustment method for a plurality of heads arranged in parallel in the carriage scanning direction has been described, but the present invention is not limited to this. The present invention is also effective for a head having a configuration in which a plurality of heads are arranged in advance in the paper feeding direction.

In the above embodiment, the method of correcting the recording position of the head that ejects a plurality of different color inks has been described, but the present invention is not limited to this. The present invention is effective even when a plurality of heads have the same color. Also,
In the case of performing so-called reciprocal printing in which recording is performed by changing the scanning direction with the same head, the present invention can be used to match the registration of the forward path with the registration of the return path.

Further, in the above-described embodiment, the range detectable by the sensor is indicated by the parallel field of view with the sensor. However, even if the range of the field of view is widened due to the lens characteristics and the like, the paper floating amount can be similarly detected from the geometrical relationship. Needless to say, the registration deviation detection can be performed.

[0064]

As described above, according to the present invention,
Even if the recording paper after pattern recording has uneven paper floating, if the same pattern is read by a plurality of sensors with different reading angles, the detection data will have a phase corresponding to the reading angle and the paper floating amount. It has a shift. Based on this phase shift, it is possible to obtain corrected detection position data from which the paper floating error of the recording paper has been removed, so that it is possible to obtain recording position correction data containing no error.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a recording apparatus used in an embodiment of the present invention and a configuration diagram of a recording head.

FIG. 2 is a diagram illustrating a registration adjustment pattern and a read signal value for explaining a conventional example.

FIG. 3 is a block diagram illustrating a configuration of an inkjet printer according to an embodiment of the present invention.

FIG. 4 is a flowchart illustrating an operation of measuring a registration deviation amount according to the embodiment of the present invention.

FIG. 5 is a flowchart illustrating an operation of measuring a registration deviation amount according to the embodiment of the present invention.

FIG. 6 is a diagram illustrating an operation of measuring a registration deviation amount according to the embodiment of the present invention.

FIG. 7 is a diagram illustrating an operation of measuring a registration deviation amount in the first embodiment of the present invention.

FIG. 8 is a diagram illustrating an operation of measuring a registration deviation amount according to the embodiment of the present invention.

FIG. 9 is a diagram illustrating an operation of measuring a registration deviation amount according to the embodiment of the present invention.

FIG. 10 is a diagram illustrating an operation of measuring a registration deviation amount according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Control part 11 Recording position detection part 12 Operation panel 13 Mechanical drive part 14 I / F part 15 Memory controller 16 Memory part 17 Head controller 18 Head part 19 Non-volatile memory for data storage 100 Paper feed roller 102 Carriage 103 Motor 105 Recording paper 106 Platen 111 Paper detection sensor 120 Black head 121 Cyan head 122 Magenta head 123 Yellow head

Continued on the front page F term (reference) 2C056 EB13 EB27 EB29 EB36 EB42 EC08 EC37 HA58 5C072 AA05 BA13 KA01 MB09 RA07 SA06 UA13 WA06 5C074 AA08 DD15 DD24 DD28 EE04 EE08 FF15 GG09

Claims (4)

[Claims] A plurality of recording position detecting units having different reading angles from each other and detecting a recording position of a pattern recorded on a recording medium; and detecting data from the plurality of recording position detecting units.
Calculating means for calculating the floating amount of the recording medium; and correcting means for correcting the recording position of the pattern detected by the recording position detecting means based on the floating amount of the recording medium to obtain a corrected recording position. A recording position reading device. 2. A pattern recorded on a recording medium is detected by a plurality of recording position detecting means having different reading angles from each other, and based on detection data from the plurality of recording position detecting means,
Calculating a paper floating amount of the recording medium, and correcting the recording position of the pattern detected by the recording position detecting means based on the paper floating amount of the recording medium to obtain a corrected recording position. Recording position reading method. 3. A recording apparatus for performing recording on a recording medium by using a plurality of recording heads, wherein each of the plurality of recording heads is connected to the recording medium by using a plurality of recording position detecting means having reading angles different from each other. Calculating means for calculating the floating amount of each of the plurality of patterns based on detection data obtained by detecting the recording positions of the recorded plurality of patterns; and detecting means for detecting the recording position based on the respective floating amounts of the plurality of patterns. Correcting means for correcting the recording positions of the plurality of patterns to obtain corrected recording positions; and recording timing correcting means for correcting recording timings of the plurality of recording heads based on the corrected recording positions by the correcting means. Recording device. 4. The recording apparatus according to claim 3, wherein said plurality of recording heads record ink colors different from each other.