JP2016087884A - Recording means discharge position adjusting device, linear error correction value generation device, image forming device, and recording means position correction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording means discharge position adjusting device capable of correcting a linear error included in the output of edge detection means, a linear error correction value generation device, an image forming device, and a recording means position correction method.SOLUTION: A recording means discharge position adjusting device 60 includes recording means 4 for recording an image in a recording medium, edge detection means 1 for detecting an edge in the width direction of the recording medium, discharge position adjusting means 6 for adjusting the droplet discharge position of the recording means, and control means 7 for adjusting the discharge position by an adjustment amount based on the output of the edge detection means, and further includes linear error correction means for correcting a linear error included in the output by a correction value. The control means executes the control according to the output of the edge detection means the linear error of which has been corrected by the linear error correction means, and the correction value has been generated by setting a positional relationship between the edge detection means and the recording medium in a linear error correction value generation means 30 so that it becomes the same as a positional relationship between the edge detection means and the recording medium in the image forming device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a recording unit discharge position adjustment device, a linearity error correction value generation device, an image forming apparatus, and a recording unit position correction method.

  2. Description of the Related Art Conventionally, there is known an ink jet type image forming apparatus that forms an image by ejecting a plurality of color droplets from a plurality of recording units onto a sheet as a recording medium and superimposing them.

  The image forming apparatus described in Patent Document 1 includes a first head unit that is a recording unit that ejects ink droplets that are droplets onto a sheet, and a recording unit that is provided further downstream in the sheet conveyance direction than the first head unit. A certain second head unit is arranged side by side in the paper transport direction. The second head unit can be moved in the paper width direction orthogonal to the paper transport direction by the head unit moving means. An edge sensor that detects an edge position of the paper in the paper width direction is provided in the vicinity of the upstream side of the first head unit and the second head unit in the paper conveyance direction. Then, when the paper is meandered and conveyed, each edge sensor is adjusted so as to correct the relative displacement of the discharge position of the second head unit to the paper with respect to the discharge position of the first head unit to the paper. The second head unit is moved in the paper width direction by an amount of movement based on the output.

  The output of the edge sensor ideally shows linearity (proportional relationship) with the edge position, but in reality, each edge sensor has its own linearity error. Therefore, it corresponds to the position shifted by the linearity error. Therefore, even if the head unit is moved by an amount of movement based on the output of the edge sensor having a linearity error, the ink liquid discharge position from the head unit with respect to the paper is adjusted, and the positional deviation is corrected, the paper width direction The discharge position shifts by the linearity error, and the color overlay accuracy decreases.

  In order to solve the above-described problems, the present invention provides a recording unit that discharges droplets toward a recording medium to record an image on the recording medium, and a recording medium width direction orthogonal to the recording medium conveyance direction of the recording medium. Edge detection means for detecting an edge position, discharge position adjustment means for adjusting the discharge position of a droplet from the recording means with respect to a recording medium, and the discharge position adjustment means with an adjustment amount based on the output of the edge detection means In a recording means discharge position adjustment apparatus comprising a control means for performing control to adjust the discharge position by a linearity error correction means for correcting a linearity error of the output of the edge detection means with a preset correction value And the control means performs the control in accordance with the output of the edge detection means whose linearity error has been corrected by the linearity error correction means, and the correction value is an image shape. The linearity is detected by detecting the edge position of the object to be detected by the edge detection means so that the positional relationship is the same as the positional relationship between the edge detection means and the recording medium when the edge detection means is provided in the apparatus. A linearity error correction value generation unit that generates an error correction value sets a positional relationship between the edge detection unit and the detection target, and is generated by the linearity error correction value generation unit. And

  As described above, according to the present invention, there is an excellent effect that the linearity error included in the output of the edge detection unit can be accurately corrected.

The figure explaining an example of the switching means of the distance of the light receiver of an edge sensor, and a detected object in a linearity error correction value generation apparatus. 1 is a schematic diagram of an image forming system according to an embodiment. FIG. 3 is a diagram illustrating a block configuration of a print head position correction mechanism. The figure explaining the structure of the edge sensor provided in a 1st inkjet printer. The figure explaining the linearity error and correction value of the edge sensor 1K. The figure explaining the linearity error and correction value of edge sensor 1Y. The figure explaining the printing position shift between the head 4K-head 4Y when the output of an edge sensor has a linearity error, and when correcting a linearity error. The figure explaining the difference of the linearity correction value in case the angle of the light receiver and detected object of an edge sensor differs with the apparatus in which an edge sensor is mounted, and a linearity error correction value generation apparatus. The figure explaining the difference in the linearity correction value when the distance between the light receiver of the edge sensor and the detected object is different between the device on which the edge sensor is mounted and the linearity error correction value generation device. The figure explaining the correction value production | generation control of the linearity error using the linearity error correction value production | generation apparatus.

  FIG. 2 is a schematic diagram of the image forming system according to the present embodiment. As shown in FIG. 2, the paper P, which is a recording medium made of a long continuous paper fed out from the paper feeding device 100, is first sent to the treatment liquid coating apparatus 101, and the front and back of the paper P A pretreatment is performed by applying a treatment liquid to the substrate. Next, the paper P pre-processed by the processing agent solution coating apparatus 101 is sent to the first ink jet printer 102a, conveyed by a plurality of rollers, and the paper P by a plurality of arranged heads 4K, 4C, 4M, 4Y. A desired image is formed by ejecting ink droplets on the front side. Thereafter, the reverse side of the paper P is reversed by the reversing device 103. The sheet P with the front and back reversed is sent to the second inkjet printer 102b, conveyed by a plurality of rollers, and ejected ink droplets on the back side of the sheet P by a plurality of heads 4K, 4C, 4M, 4Y. A desired image is formed. In this way, after images are formed on both sides of the paper P, the system is sent to the post-processing device 104 to perform predetermined post-processing.

  FIG. 3 is a diagram illustrating a block configuration of the head position correction device 60 provided in the first inkjet printer 102a. Since the second ink jet printer 102b is the same, the description thereof is omitted.

  As shown in FIG. 3, the first inkjet printer 102a discharges ink droplets of black (K), cyan (C), magenta (M), and yellow (Y) onto the paper P along the paper transport direction. Are provided with a plurality of heads 4K, 4C, 4M, 4Y. The paper P fed out from the paper feeding device 100 is conveyed under the heads 4K, 4C, 4M, and 4Y, and ink droplets of each color are sequentially ejected onto the paper P from the heads 4K, 4C, 4M, and 4Y. An image is formed.

  The first inkjet printer 102a is attached to the heads 4C, 4M, and 4Y other than the head 4K, and actuators 6C, 6M, and 6Y for moving them in the paper width direction (main scanning direction) orthogonal to the paper transport direction. It has. Further, the heads 4K, 4C, 4M, and 4Y are provided upstream of the sheet conveyance direction, and include edge sensors 1K, 1C, 1M, and 1Y for detecting the edge position of the sheet P in the sheet width direction. . At the time of image formation, the sheet edge position is detected by the edge sensors 1K, 1C, 1M, and 1Y installed in the vicinity of the sheet P. Then, the actuators 6C, 6M, 6Y are driven in accordance with the detected paper edge position, and the heads 4C, 4M, 4Y connected thereto are moved in the paper width direction by a movement amount corresponding to the paper edge position.

  The amount of movement of the paper edge relative to the reference value is detected at the mounting position of each edge sensor 1K, 1C, 1M, 1Y. As shown in FIG. 4, each of the edge sensors 1K, 1C, 1M, and 1Y is configured by fixing projectors 2K, 2C, 2M, and 2Y and light receivers 3K, 3C, 3M, and 3Y to a holder. The edge position is converted into detection voltages 9K, 9C, 9M, and 9Y and output to the controller 7. The head position moving amount data 15C, 15M, 15Y is sent from the controller 7 to the actuators 6C, 6M, 6Y based on the detection voltages 9C, 9M, 9Y, so that the heads 4C, 4M are driven by the actuators 6C, 6M, 6Y. , 4Y are moved in the paper width direction.

  The memory 17 provided in the controller 7 generates each edge sensor 1K, 1C, 1M, 1Y so as to cancel out the linearity error detected by the linearity error correction value generation device 30 (see FIG. 1) described later. The corrected values 23K, 23C, 23M, and 23Y are stored. The correction values 23K, 23C, 23M, and 23Y are generated by the linearity error correction value generation device 30 shown in FIG. 1 in the device manufacturing process.

  In the controller 7, correction values 23K, 23C, generated for the respective edge sensors 1K, 1C, 1M, 1Y with respect to the values of the detected voltages 9K, 9C, 9M, 9Y detected by the respective edge sensors 1K, 1C, 1M, 1Y. The actual edge position of the paper P is recognized by adding and subtracting 23M and 23Y. Then, movement amount data 15C, 15M, and 15Y used when the heads 4C, 4M, and 4Y are moved by the actuators 6C, 6M, and 6Y are determined from the actual edge positions of the paper P thus recognized. Details of this control will be described later with reference to FIG.

  FIG. 4 is a diagram illustrating the configuration of the edge sensor 1 provided in the first inkjet printer 102a. When the edge sensor 1K, 1C, 1M, 1Y is optionally added to each head 4K, 4C, 4M, 4Y after the first inkjet printer 102a is installed at the customer, the edge sensors 1K, 1C, 1M, 1Y The mounting position is limited by the space in the device. Therefore, the positional relationship between all the edge sensors 1K, 1C, 1M, and 1Y and the paper P is not always the same.

  In FIG. 4, the distance between the light receivers and the detected objects of the edge sensors 1K, 1C, 1M, and 1M is 62 [mm] for the edge sensors 1K and 1C, 65 [mm] for the edge sensor 1M, and 66 for the edge sensor 1Y. .5 [mm]. Further, the angle between the light receiver and the detected object of the edge sensors 1K, 1C, and 1M is 0 [°] in the edge sensors 1C, 1M, and 1Y (paper P is perpendicular to the optical axis connecting the light projector 2 to the light receiver 3). It is. In the edge sensor 1K, it is 6 [°] (the inclination of the paper P is 6 [°] with respect to a perpendicular perpendicular to the optical axis connecting the light projector 2 to the light receiver 3).

  Hereinafter, a method for generating the correction values 23K, 23C, 23M, and 23Y of the edge sensors 1K, 1C, 1M, and 1Y provided at such mounting positions will be described. Needless to say, the correction values 23K, 23C, 23M, which will be described below are also applied when the distance between the light receiver and the detected object and the angle between the light receiver and the detected object of the edge sensors 1K, 1C and 1M are other than the above. Implementation of the 23Y generation method is possible.

  Here, for example, a CCD-type transmission sensor has a linearity error of about ± 28 [μm] due to specifications, and a photodiode-type transmission-side sensor has ± 100 [μm] or more. Has a linearity error. That is, even in a CCD-type transmissive sensor with little linearity error, for example, when the paper edge moves 100 [μm] in the paper width direction, the sensor displacement is in the range of 42 [μm] to 156 [μm] at maximum. Will vary. Therefore, the color misregistration accuracy (several tens [μm]) required for the ink jet printer cannot be achieved.

  FIG. 5 is a diagram for explaining the linearity error and the correction value of the edge sensor 1K. 5A, at the position of the light receiver-detected object distance A = 62 [mm] and the light receiver-detected object angle B = 6 [°] as shown in FIG. 5B with respect to the edge sensor 1K. The relationship between the edge movement amount ΔL and the sensor detection value when the detected object 18 is moved in the direction of arrow C in FIG.

  For example, when the edge movement amount ΔL = 30 [μm], the sensor detection value 11K is ideally 30 [μm] as shown by the solid line in FIG. However, in actual measurement, as indicated by a broken line in FIG. 5A, the sensor detection value 11K is 50 [μm], and a linearity error of 20 [μm] occurs. Therefore, for the edge sensor 1K, when the sensor detection value 11K is 50 [μm], 20 [μm] is subtracted as the correction value 23K. Thereby, when the edge movement amount ΔL = 30 [μm], the corrected sensor detection value 11K becomes 30 [μm], and the linearity error of the edge sensor 1K can be canceled out.

  FIG. 6 is a diagram for explaining the linearity error and sensor detection value of the edge sensor 1Y. FIG. 6A shows that the distance between the light receiver and the detected object A is 66.5 [mm] and the angle between the light receiver and the detected object B is 0 [°] as shown in FIG. 6B with respect to the edge sensor 1Y. The relationship between the edge movement amount ΔL and the sensor detection value when the detected object 18 provided at the position is moved in the direction of arrow C in FIG.

  For example, when the edge movement amount ΔL = 80 [μm], the sensor detection value 11Y is ideally 80 [μm] as shown by the solid line in FIG. However, in actual measurement, as indicated by a broken line in FIG. 6A, the sensor detection value 11Y is 50 [μm], and a linearity error of −30 [μm] occurs. Therefore, for the edge sensor 1Y, when the sensor detection value 11Y is 50 [μm], 30 [μm] is added as the correction value 23Y. Thereby, when the edge movement amount ΔL = 80 [μm], the corrected sensor detection value 11Y becomes 80 [μm], and the linearity error of the edge sensor 1Y can be canceled.

  FIG. 7 is a diagram for explaining the printing position deviation between the head 4K and the head 4Y when the output of the edge sensor 1 has a linearity error and when the linearity error is corrected.

  First, as shown by the solid lines in FIGS. 7A and 7B, a case where the paper P is conveyed without meandering will be described. In this case, when the print position by the head 4K in the paper width direction from the edge of the paper P is K = 100 [μm], the actuator 6Y causes the head 4Y to move so that the print position by the head 4Y becomes Y = 100 [μm]. Adjust the position. The edge sensor 1K has the linearity error shown in FIG. 5, and the edge sensor 1Y has the linearity error shown in FIG.

  Further, when the paper P meanders and the paper P is conveyed at the position indicated by the dotted line in FIG. 7, the edge position at the detection position of the edge sensor 1K moves 30 [μm] to the right with respect to the paper conveyance direction. Shall. Further, it is assumed that the edge position at the detection position of the edge sensor 1Y moves 80 [μm] to the right with respect to the paper transport direction.

  When the linearity correction of the edge sensor 1 is not performed, as shown in FIG. 7A, the sensor detection value 11K of the edge sensor 1K when ΔL = 30 [μm] is 50 [μm], and ΔL = 80 The sensor detection value 11Y of the edge sensor 1Y at [μm] is 50 [μm]. For this reason, the amount of meandering between KY is recognized as 0 [μm], and the amount of movement of the head 4Y by the actuator 6Y is 0 [μm]. Therefore, the print position in the paper width direction from the edge of the paper P is K = 70 [μm], Y = 20 [μm], and a color shift that is a shift of the print position of 50 [μm] occurs between KY. To do.

  On the other hand, as shown in FIG. 7B, by correcting the measured sensor detection value 11K of the edge sensor 1K by −20 [μm], the corrected sensor detection value 11K of the edge sensor 1K is obtained. Is 30 [μm]. Further, by correcting +30 [μm] with respect to the actual sensor detection value 11Y of the edge sensor 1Y, the corrected sensor detection value 11Y of the edge sensor 1Y becomes 80 [μm]. Therefore, it can be recognized that the edge position in the edge sensor 1Y is 50 [μm] away from the edge position in the edge sensor 1K in the paper width direction. Therefore, by moving the head 4Y by 50 [μm] in the main scanning direction, which is the paper width direction, by the actuator 6Y, the print position in the paper width direction from the edge of the paper P is K = 70 [μm], Y = 70 [ μm], and the color shift between KY can be canceled.

  Here, the linearity error of the edge sensor is very sensitive in reproducibility. For example, in the case of a CCD transmission type sensor, if the distance between the light receiver and the detection object changes by 1.5 [mm], the edge sensor The displacement amount is shifted by about 10 [μm]. Further, when the angle between the light receiver and the detected object changes by 6 [°], the displacement amount of the edge sensor may be displaced by about 10 [μm].

  FIG. 8 illustrates the difference in linearity correction value when the angle between the light receiver 3 of the edge sensor 1 and the detected object 18 is different between the device on which the edge sensor 1 is mounted and the linearity error correction value generation device 30. It is a figure to do. Table 1 shows set values of the light receiver-detected object distance A and the light receiver-detected object angle B in the apparatus in which the edge sensor 1 is mounted and the linearity error correction value generating apparatus 30.

  In FIG. 4, the edge sensor 1 </ b> K is attached to the first inkjet printer 102 a at a position where the light receiver-detected object angle B = 6 [°]. However, when the angle B between the light receiver and the detected object of the linearity error correction value generation device 30 shown in FIG. 1 is fixed to 0 [°], which is the same as that of the edge sensor 1C, the linearity error is canceled out. May not be possible.

  8A, the edge sensor 1K is positioned at a position where the light receiver-detected object distance A = 62 [mm] and the light receiver-detected object angle B = 0 [°] as shown in FIG. 8B. A relationship between the edge movement amount ΔL and the sensor detection value when the provided detection object 18 is moved in the direction of arrow C in FIG.

  For example, when the edge movement amount ΔL = 40 [μm], the sensor detection value 11K is ideally 40 [μm] as shown by the solid line in FIG. However, in actual measurement, as indicated by a broken line in FIG. 8A, the sensor detection value 11K is 50 [μm], and a linearity error of 10 [μm] occurs. On the other hand, when the receiver-detector angle B = 6 [°] as shown in FIG. 4, the linearity error is 20 [μm] even at the same detection position, and the receiver-detector angle B is 6 [°]. If they are different, the linearity error at the same sensor detection value 11K is different by 10 [μm]. As a result, the correction position of the head 4 also has an error of 10 [μm], and the printing position is also shifted by 10 [μm].

  Therefore, the linearity error correction value generation device 30 used in this embodiment is configured to be able to switch the angle B between the light receiver and the detected object to an arbitrary angle, and under the same conditions as the device on which the edge sensor 1 is mounted. The sensor detection value can be measured. Thereby, the linearity error shift of the edge sensor 1 does not occur between the device on which the edge sensor 1 is mounted and the linearity error correction value generation device 30. Therefore, the quality of the printed image can be improved by improving the correction accuracy of the head position and reducing the color misregistration.

  FIG. 9 illustrates the difference in linearity correction value when the distance between the light receiver 3 of the edge sensor 1 and the detected object 18 is different between the device on which the edge sensor 1 is mounted and the linearity error correction value generation device 30. It is a figure to do. Table 2 shows the set values of the light receiver-detected object distance A and the light receiver-detected object angle B in the apparatus in which the edge sensor 1 is mounted and the linearity error correction value generating apparatus 30.

  In FIG. 4, the edge sensor 1 </ b> Y is attached to the first inkjet printer 102 a at a position where the distance between the light receiver and the detected object A is 66.5 [mm]. However, regarding the edge sensor 1Y, when the distance A between the light receiver and the detected object of the linearity error correction value generation device 30 shown in FIG. 1 is fixed to 65 [mm] as in the edge sensor 1M, the edge sensor 1Y is measured. In some cases, the linearity error cannot be canceled.

  9A, the edge sensor 1Y is positioned at a position where the light receiver-detected object distance A = 65 [mm] and the light receiver-detected object angle B = 0 [°] as shown in FIG. 9B. FIG. 9 shows the relationship between the edge movement amount ΔL and the sensor detection value when the detected object 18 is moved in the direction of arrow C in FIG.

  For example, when the edge movement amount ΔL = 70 [μm], the sensor detection value 11Y is ideally 70 [μm] as shown by the solid line in FIG. However, in actual measurement, as indicated by a broken line in FIG. 9A, the sensor detection value 11Y is 50 [μm], and a linearity error of 20 [μm] occurs.

  On the other hand, when A = 66.5 [mm] as shown in FIG. 4, the linearity error is 30 [μm] even at the same detection position, and the distance A between the light receiver and the detected object is different by 1.5 [mm]. The linearity error at the same sensor detection value 11Y is different by 10 [μm]. As a result, the correction position of the head 4 also has an error of 10 [μm], and the printing position is also shifted by 10 [μm].

  Therefore, the linearity error correction value generation device 30 used in the present embodiment is configured to be able to switch the distance A between the light receiver and the detected object to an arbitrary distance, under the same conditions as the device on which the edge sensor 1 is mounted. The sensor detection value can be measured. Thereby, the linearity error shift of the edge sensor 1 does not occur between the device on which the edge sensor 1 is mounted and the linearity error correction value generation device 30. Therefore, the quality of the printed image can be improved by improving the correction accuracy of the head position and reducing the color misregistration.

  FIG. 1 is a diagram for explaining an example of a switching means for switching the distance and angle between the light receiver 3 of the edge sensor 1 and the detected object 18 in the linearity error correction value generation device 30 used in the present embodiment.

  The linearity error correction value generation device 30 includes an actuator 25 and a sensor base 29 provided on one frame 28, and a detection object 18 attached to the actuator 25. The edge sensor 1 mounted on the first inkjet printer 102a is fixed on the sensor base 29 and is used to measure the linearity of the edge sensor 1.

  For example, as shown in FIG. 1A, changing the position of the sensor base 29 with respect to the frame 28 also changes the position of the light receiver 3 with respect to the detected object 18, so that the distance A between the light receiver and the detected object is changed. Is possible. Further, as shown in FIG. 1B, by using a sensor base 29 having a triangular cross section having an inclination of an angle B with respect to an installation surface on which the sensor base 29 of the frame 28 is installed, the distance between the light receiver and the detected object It is possible to change the angle B.

  FIG. 1C is a schematic diagram showing a light receiver-detected object distance A and a light receiver-detected object angle B between the edge sensor 1 and the detected object 18 in the linearity error correction value generating device 30. Table 3 shows the set values of the distance A between the light receiver and the detected object and the angle B between the light receiver and the detected object when the mounting position of the edge sensor 1 in the first ink jet printer 102a satisfies the conditions shown in FIG. Is shown.

  FIG. 10 is a diagram for explaining linearity error correction value generation control using the linearity error correction value generation device 30. In the linearity error correction value generating device 30, as shown in FIG. 1, the positional relationship between the edge sensor 1 and the detected object 18 is determined based on the edge sensor 1 and the paper P when the edge sensor 1 is provided in the first inkjet printer 102a. Set to be the same positional relationship as. Then, ΔL is sent to the actuator 25 as the command position data 24, and the position of the detected object 18 is moved by ΔL by the actuator 25. When the position of the detected object 18 changes, the detection voltage 19 of the edge sensor 1 changes. The detection voltage 19 is converted into digital data by the A / D converter 20 and output as detection position data 21. Each time the detection position data 21 changes by a predetermined value, the arithmetic circuit 22 calculates and detects a difference from the command position data 24 at that time, that is, a linearity error 26. Then, the correction value 23 is generated by inverting the sign of the linearity error 26 in the arithmetic circuit 27. Thus, the generated correction value 23 is written in the memory 17 in the first inkjet printer 102a.

  Table 4 shows the linearity error 26 calculated from the detection position data 21 and the command position data 24 when the detection position data 21 changes by 10 [μm], and the sign of the linearity error 26 is inverted. The corrected value 23 is shown.

  As shown in Table 1, when the command position data 24 when the detection position data 21 is 50 [μm] is 45 [μm], the linearity error 26 is +5 [μm], and the actual movement of the detected object 18 is detected. It is detected that it has moved 5 [μm] more than the amount. At this time, the correction value 23 is set to −5 [μm] by inverting the sign of the linearity error 26. That is, when the linearity error 26 is detected as 50 [μm] by the actual measurement of the edge sensor 1, the correction value −5 [μm] is applied to the detected value of the linearity error 26, and the corrected value is obtained. Is recognized as 45 [μm]. Thereby, the movement amount of the detected object 18 detected by the edge sensor 1 can be matched with the command position data 24 (= actual movement amount ΔL of the detected object 18).

  In the present embodiment, the ejection position of the ink liquid from the head 4 with respect to the paper P is adjusted by moving the head 4 by the actuator 6 by the movement amount according to the output of the edge sensor 1. The configuration for adjusting the position is not limited to this. For example, a plurality of nozzles that eject ink liquid are provided on the surface of the head 4 facing the paper P in the paper width direction. Then, among the plurality of nozzles, the discharge position is adjusted by discharging the ink liquid from the nozzle at the position where the discharge position is shifted in the paper width direction by an adjustment amount corresponding to the output of the edge sensor 1. A configuration can also be employed.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
Recording means such as a head 4 that discharges droplets toward a recording medium such as paper P to record an image on the recording medium, and an edge position in the recording medium width direction perpendicular to the recording medium conveyance direction of the recording medium are detected. An adjustment amount based on the output of the edge detection means such as the edge detection means, the discharge position adjustment means such as the actuator 6 for adjusting the discharge position of the droplets from the recording means on the recording medium, and the edge detection means, In a recording unit discharge position adjustment apparatus such as a head position correction apparatus 60 provided with a control unit such as a controller 7 that performs control for adjusting the discharge position by the discharge position adjustment unit, the linearity of the output of the edge detection unit It has linearity error correction means such as a controller 7 for correcting the error with a preset correction value, and the control means is configured to correct the linearity error correction. The control is performed in accordance with the output of the edge detection unit whose linearity error has been corrected by a stage, and the correction value is detected when the edge detection unit is provided in an image forming apparatus such as the first inkjet printer 102a. Linearity error correction for generating the correction value of the linearity error by detecting the edge position of the detection object such as the detection object 18 by the edge detection means so that the positional relationship is the same as the positional relationship between the means and the recording medium. The linearity error correction value generation means such as the value generation device 30 sets the positional relationship between the edge detection means and the detection object, and is generated by the linearity error correction value generation means.
In (Aspect A), since the discharge position is adjusted by the discharge position adjusting means with an adjustment amount based on the output of the edge detecting means whose linearity error has been corrected by the linearity error correcting means, the discharge position is recorded. It is possible to suppress the deviation of the linearity error in the medium width direction. Further, when the positional relationship between the distance and the angle between the edge detection unit and the recording medium is different, the linearity error is changed even with the same edge detection unit, and the correction value corresponding to the linearity error is also different. Therefore, the correction value is generated by the linearity error correction value generation unit in the same positional relationship as the positional relationship between the edge detection unit and the recording medium when the edge detection unit is provided in the image forming apparatus. Thereby, the correction value generated by the linearity error correction value generation unit corresponds to the linearity error of the output of the edge detection unit provided in the image forming apparatus. Accordingly, the linearity error of the output of the edge detection unit provided in the image forming apparatus can be accurately corrected by the correction value generated by the linearity error correction value generation unit.
(Aspect B)
Correction of edge detection means such as edge sensor 1 that detects the edge position of the detection object such as detection object 18 and arithmetic circuit 27 that generates a correction value for correcting the linearity error of the output of the edge detection means. In the linearity error correction value generation device such as the linearity error correction value generation device 30 provided with the value generation unit, when the edge position is detected by the edge detection unit, the distance and angle between the edge detection unit and the detection target are determined. It can be changed. According to this, as described in the above embodiment, the distance and angle between the edge detection unit and the detection target are changed, and the positional relationship between them is determined as the positional relationship between the edge detection unit and the recording medium in the image forming apparatus. The correction value can be generated by setting the same as. Therefore, by using the generated correction value, it is possible to accurately correct the linearity error of the output of the edge detection unit provided in the image forming apparatus.
(Aspect C)
In the recording means discharge position adjusting apparatus described in (Aspect A), the correction value generated by the linearity error correction value generation apparatus described in (Aspect B) is used. According to this, as described in the above-described embodiment, the edge detection unit uses the correction value generated by the linearity error correction value generation device by changing the distance and angle between the edge detection unit and the detection target. The linearity error of the output can be corrected with high accuracy.
(Aspect D)
In (Aspect C), for each of the plurality of edge detection means arranged side by side in the recording medium conveyance direction, the correction value is determined by the distance between each edge detection means and the detection target to each of the image forming apparatuses. The linearity error correction value generation device changes the distance so as to be the same as the distance between each edge detection means and the recording medium when the edge detection means is provided. According to this, as described in the above embodiment, even when the distance between the edge detection unit and the recording medium varies depending on the use part of each edge detection unit on the image forming apparatus, The linearity error can be detected with high accuracy.
(Aspect E)
In (Aspect C) or (Aspect D), for each of the plurality of edge detection means arranged side by side in the recording medium conveyance direction, the correction value is determined by the angle between each edge detection means and the detection object. The linearity error correction value generating device is used to change the angle so that the positional relationship between each edge detecting unit and the recording medium when each edge detecting unit is provided in the image forming apparatus is the same. Is. According to this, as described in the above embodiment, even when the angle between the edge detection unit and the recording medium is different depending on the use part of each edge detection unit on the image forming apparatus, all the edge detection units are used. The linearity error can be detected with high accuracy.
(Aspect F)
In (Aspect A), (Aspect C), (Aspect D) or (Aspect E), the discharge position adjusting means is a moving means such as an actuator 6 for moving the recording means in the recording medium width direction, and the adjustment The amount is a moving amount by which the recording unit is moved by the moving unit. According to this, as described in the above embodiment, the ejection position can be adjusted by moving the recording means.
(Aspect G)
A plurality of recording means arranged in the recording medium conveyance direction for discharging droplets toward the recording medium and recording an image on the recording medium, and a recording medium width direction orthogonal to the recording medium conveyance direction of the recording medium An image forming apparatus such as a first inkjet printer 102a having a plurality of edge detecting means for detecting the edge position of the ink and an ejection position adjusting means for adjusting the ejection position of the droplets of at least one recording means with respect to the recording medium And (Aspect C), (Aspect D), (Aspect E) or (Aspect F). According to this, as described in the above embodiment, the linearity error of the output of each edge detection unit is accurately corrected, and the relative displacement of the discharge position of each recording unit to the recording medium is reduced. Further, the color overlay accuracy in the recording medium width direction can be improved.
(Aspect H)
In the vicinity of each of the recording means such as the plurality of heads 4 arranged in the recording medium conveyance direction, the edge position of the recording medium in the recording medium width direction orthogonal to the recording medium conveyance direction is detected by the edge sensors 1 and the like. An edge position detecting step detected by the means, a linearity error correcting step for correcting the linearity error of the output of each edge detecting means with a correction value preset by the linearity error correcting means, and the linearity error correcting means The other recording means other than the recording means provided at least on the most upstream side in the recording medium transport direction among the plurality of recording means with an amount of movement based on the output of each edge detecting means whose linearity error has been corrected by the actuator And a recording means moving step for moving the recording medium in the recording medium width direction by a moving means such as 6. The edge position of the detection object such as the detection object 18 is edge-detected so as to have the same positional relationship as that between the edge detection means and the recording medium when the edge detection means is provided in the image forming apparatus such as the printer 102a. Generated by the linearity error correction value generation means by setting the positional relationship between the edge detection means and the object to be detected by the linearity error correction value generation means that detects the linearity error and generates the correction value of the linearity error. It is. According to this, as described in the above embodiment, it is possible to accurately correct the linearity error of the output of each edge detection unit provided in the image forming apparatus.

DESCRIPTION OF SYMBOLS 1 Edge sensor 2 Emitter 3 Light receiver 4 Head 6 Actuator 7 Controller 9 Detection voltage 11 Sensor detection value 15 Movement amount data 17 Memory 18 Detected object 19 Detection voltage 20 Converter 21 Detection position data 22 Arithmetic circuit 23 Correction value 24 Command position data 25 Actuator 26 Linearity error 27 Arithmetic circuit 28 Frame 29 Sensor base 30 Linearity error correction value generation device 60 Head position correction device 100 Paper feed device 101 Processing agent liquid coating device 102a First inkjet printer 102b Second inkjet printer 103 Inversion device 104 Post-processing equipment

JP 2011-136526 A

Claims (8)

A recording means for discharging droplets toward the recording medium to record an image on the recording medium;
Edge detection means for detecting an edge position in the recording medium width direction perpendicular to the recording medium conveyance direction of the recording medium;
Discharge position adjusting means for adjusting the discharge position of the droplets from the recording means with respect to the recording medium;
In a recording means discharge position adjustment apparatus comprising a control means for performing control to adjust the discharge position by the discharge position adjustment means with an adjustment amount based on the output of the edge detection means,
Linearity error correction means for correcting the linearity error of the output of the edge detection means with a preset correction value;
The control means performs the control according to the output of the edge detection means whose linearity error has been corrected by the linearity error correction means,
The edge position of the detection target is the edge detection unit so that the correction value has the same positional relationship as the positional relationship between the edge detection unit and the recording medium when the edge detection unit is provided in the image forming apparatus. The linearity error correction value generating means detects the linearity error and generates a correction value of the linearity error, sets the positional relationship between the edge detection means and the detection object, and generates the linearity error correction value generation means. An apparatus for adjusting the discharge position of recording means. Edge detection means for detecting the edge position of the detection object;
In a linearity error correction value generation device comprising correction value generation means for generating a correction value for correcting a linearity error of the output of the edge detection means,
A linearity error correction value generation device characterized in that, when the edge position is detected by the edge detection means, the distance and angle between the edge detection means and the detection object can be changed. In the recording means discharge position adjusting device according to claim 1,
The recording means discharge position adjusting apparatus according to claim 2, wherein the linearity error correction value generating means is the linearity error correction value generating apparatus according to claim 2. In the recording means discharge position adjusting device according to claim 3,
For each of the plurality of edge detection means arranged side by side in the recording medium conveyance direction, the correction value is determined by determining the distance between each edge detection means and the detection target, and providing each edge detection means in the image forming apparatus. The recording means discharge position generated by changing the distance by the linearity error correction value generation device so that the distance between each edge detection means and the recording medium is the same Adjustment device. In the recording means discharge position adjusting device according to claim 3 or 4,
For each of the plurality of edge detection means arranged side by side in the recording medium conveyance direction, the correction value is determined based on the angle between each edge detection means and the detection target, and each edge detection means is provided in the image forming apparatus. The recording unit discharge is generated by changing the angle by the linearity error correction value generation device so that the positional relationship between each edge detection unit and the recording medium is the same. Positioning device. In the recording means discharge position adjusting device according to claim 1, 3, 4, or 5,
The discharge position adjusting means is a moving means for moving the recording means in the recording medium width direction,
The recording means discharge position adjusting apparatus according to claim 1, wherein the adjustment amount is a movement amount by which the recording means is moved by the moving means. A plurality of recording means arranged side by side in the recording medium conveyance direction for ejecting droplets toward the recording medium and recording an image on the recording medium;
A plurality of edge detection means for detecting an edge position in the recording medium width direction perpendicular to the recording medium conveyance direction of the recording medium;
In an image forming apparatus comprising: a discharge position adjusting unit that adjusts a discharge position of a droplet of at least one recording unit with respect to a recording medium;
An image forming apparatus comprising the recording unit discharge position adjusting device according to claim 1. An edge position detection step of detecting an edge position in the recording medium width direction perpendicular to the recording medium conveyance direction of the recording medium by a plurality of edge detection means in the vicinity of each of the plurality of recording means provided side by side in the recording medium conveyance direction; ,
A linearity error correction step of correcting the linearity error of the output of each edge detection means with a correction value set in advance by the linearity error correction means;
The amount of movement based on the output of each edge detecting means whose linearity error has been corrected by the linearity error correcting means, and other than the recording means provided at least on the most upstream side in the recording medium transport direction among the plurality of recording means. In a recording means position correction method comprising a recording means moving step of moving other recording means in the recording medium width direction by a moving means,
The edge position of the detection target is the edge detection unit so that the correction value has the same positional relationship as the positional relationship between the edge detection unit and the recording medium when the edge detection unit is provided in the image forming apparatus. The linearity error correction value generating means detects the linearity error and generates a correction value of the linearity error, sets the positional relationship between the edge detection means and the detection object, and generates the linearity error correction value generation means. A recording means position correcting method characterized by the above-mentioned.

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