JP2011242286A - Eccentricity measurement method, eccentricity measurement instrument, control program of the eccentricity measurement instrument, rotating device, and method for manufacturing the rotating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the degradation in precision of rotation phase control due to eccentricity of an identification code group relative to a revolving shaft of a rotary scale in a rotating device using the rotary scale.SOLUTION: A control device 100 includes: means which calculates a maximum or minimum value of ratios of detection pulse widths of slits SL by a first detection sensor 22 and detection pulse widths of the slits SL by a second detection sensor 23; means which calculates a variation in width of the slits SL in accordance with the maximum or minimum value; means which calculates an eccentricity of the slit group relative to a revolving shaft of a rotary scale 2 in accordance with the variation in width of the slits SL; means which calculates an eccentricity phase of the slit group relative to the revolving shaft of the rotary scale 2 in accordance with a rotation phase of the rotary scale 2 when the ratio of detection pulse widths reaches the maximum or minimum value; and means which corrects rotation errors of a carrying drive roller 11 on the basis of the eccentricity and the eccentric phase of the slit group.

Description

  The present invention provides an eccentricity measuring method for measuring an eccentricity amount or an eccentricity phase of the identification code group with respect to the rotary shaft of a rotary scale in which a plurality of identification codes are arranged at equal intervals on the same circumference to form an identification code group, The present invention relates to an eccentricity measuring device, a control program for the eccentricity measuring device, a rotating device provided with a control device for performing rotation control of a rotating body using a rotary scale, and a method for manufacturing the rotating device.

  A rotation device using a so-called rotary scale is known as a technique for controlling the rotation speed or rotation phase of a rotating body rotating with a driving force of a driving force source such as a DC motor with high accuracy. This rotary scale has a plurality of identification codes (slits, etc.) arranged at equal intervals on the same circumference to form an identification code group, and is provided so as to rotate together with a rotating body or a driving shaft of a driving force source. . A sensor is arranged at a position where the identification code of the rotary scale can be detected. From this sensor, a pulse signal having a period corresponding to the rotation speed of the rotary scale (detection signal of the identification code) is output by the number corresponding to the rotation amount. Therefore, the rotational speed or rotational phase of the rotating body can be controlled by adjusting the voltage applied to the driving force source based on the output signal of the sensor (see, for example, Patent Document 1 or 2).

  However, in the rotary scale, ideally, the axis of the rotation axis should coincide with the center of the identification code group, but in reality, the identification code group is eccentric with respect to the rotation axis within the range of manufacturing tolerances. Formed in a state. Therefore, in a rotating device using a rotary scale, there arises a problem that the accuracy of rotational speed control or rotational phase control is reduced due to the eccentricity of the identification code group with respect to the rotary shaft of the rotary scale.

  As a prior art aiming at solving such a problem, for example, a plurality of sensor sets each having a sensor for detecting an identification code arranged at 180 ° opposite positions are arranged at different phases. The gain and phase of each output signal of these sensors can be individually adjusted based on the period of one pulse signal per rotation obtained by dividing the signal obtained by A / D conversion of the output signals of these sensors. There is known a rotation speed control device that controls the rotation speed of a motor based on a signal obtained by adding the output signals obtained by adjusting the gain and the phase (for example, see Patent Document 1).

  As another conventional technique for solving the above-mentioned problem, two sensors for detecting an identification code are arranged with an arbitrary phase difference, and the calculation is ½ of the output signal difference of the sensor. Calculate the error correction value that matches the amplitude and phase of the error component included in the signal with the error component amplitude and phase included in the output signal of any one of the sensors, and correct the sensor output signal with the error correction value By extracting the signal of only the rotational speed fluctuation component from which the phase error caused by the eccentricity and elliptical arrangement of the identification code group with respect to the rotary shaft of the rotary scale is removed, the motor is based on the signal of only the rotational speed fluctuation component. A technique for reducing fluctuations in the rotational speed of a motor by controlling the rotational speed of the motor is known (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 61-227689 JP 2009-183113 A

  However, any of the conventional techniques disclosed in Patent Document 1 or Patent Document 2 is a technique for suppressing fluctuations (rotational unevenness) in the rotational speed of the motor. That is, the technology for reducing the decrease in accuracy of the rotational phase control due to the eccentricity of the identification code group with respect to the rotary shaft of the rotary scale is neither disclosed nor suggested by Patent Document 1 or Patent Document 2. .

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an accuracy of rotational phase control caused by eccentricity of an identification code group with respect to a rotary shaft of a rotary scale in a rotary device using a rotary scale. Is to reduce the decrease in
Another object of the present invention is to make it possible to easily measure the amount of eccentricity or the phase of an identification code group with respect to the rotation axis of a rotary scale.

<First Aspect of the Present Invention>
According to a first aspect of the present invention, there is provided a rotation mechanism for rotating a rotary scale having a plurality of identification codes arranged at equal intervals on the same circumference to form a group of identification codes with a driving force of a driving force source, and the identification A first detection sensor disposed at a position where a code can be detected; a second detection sensor disposed at a position where the phase is shifted with respect to the first detection sensor at a position where the identification code can be detected; An arithmetic device, and the arithmetic device calculates a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor. Means for calculating a variation amount of the width of the identification code detected by the first detection sensor or the second detection sensor from the maximum value or the minimum value of the ratio of the detection pulse widths, and the width of the identification code The amount of variation And means for calculating the amount of eccentricity of the identification code group with respect to the rotation axis of the rotary scale, it is eccentric measuring apparatus characterized.

  Here, the phase difference between the arrangement position of the first detection sensor and the arrangement position of the second detection sensor is α, the detection pulse width of the identification code by the first detection sensor is T (φ, 0), and the second detection sensor. The detection pulse width of the identification code by T (φ, α), the width of the identification code detected by the first detection sensor or the second detection sensor (the length in the rotation direction of the identification code on the locus of the detection point of the sensor) L, the theoretical value (value when the eccentricity is 0) is Lc, the actual moving speed of the identification code at the detection point of the first detection sensor and the second detection sensor is V, the theoretical value is Vc, and the speed fluctuation of V The amount is V (φ), the variation amount of L is ΔL, and the eccentricity amount of the identification code group with respect to the rotary axis of the rotary scale is e.

  In a state where the rotary scale is rotated by the driving force of the driving force source, the detection pulse width T (φ, 0) of the identification code by the first detection sensor is obtained from the following equation (1). The detection pulse width T (φ, α) of the identification code by the second detection sensor can be obtained from the following equation (2).

  That is, the detection pulse width of the identification code by the first detection sensor or the second detection sensor varies depending on the eccentricity of the identification code group with respect to the rotation axis of the rotary scale. However, the fluctuation in the detection pulse width of the identification code by the first detection sensor or the second detection sensor also includes a rotational fluctuation component of the driving force source due to cogging, rotational load fluctuation, and the like. Therefore, the amount of eccentricity of the identification code group with respect to the rotation axis of the rotary scale cannot be accurately specified from the fluctuation of the detection pulse width of the identification code by the first detection sensor or the second detection sensor.

  Therefore, in the present invention, first, the maximum value or the minimum value of the ratio between the detection pulse width T (φ, 0) of the identification code by the first detection sensor and the detection pulse width T (φ, α) of the identification code by the second detection sensor. Calculate the value. That is, the rotational fluctuation component of the driving force source included in the detection pulse width of the identification code by the first detection sensor and the rotational fluctuation component of the driving force source included in the detection pulse width of the identification code by the second detection sensor should be exactly the same. Therefore, by taking the ratio of the two, it is possible to extract only the pulse width variation component due to the eccentricity of the identification code group with respect to the rotary axis of the rotary scale (formula (3)).

  However, since what is obtained from the first detection sensor and the second detection sensor is a signal corresponding to the time, φ cannot be specified in real time. That is, since the rotary scale does not actually rotate at a constant speed, φ = ωt is not satisfied. Therefore, if φ = g (t) is set in consideration of the nonlinearity of time and φ, the ratio r (t) between the detection pulse width of the identification code by the first detection sensor and the detection pulse width of the identification code by the second detection sensor ) Is obtained from the following equation (4).

  Here, r (t) changes while taking a maximum value and a minimum value alternately. Therefore, first, in order to obtain the maximum value and the minimum value, r (t) is differentiated by g (t) to obtain g (t) at which r (t) takes the extreme value (Expression (5) to Expression (7)). )).

  When g (t) that satisfies this condition is β, the maximum value r (t) max and the minimum value r (t) min of r (t) are expressed by the following equations (8) and (9).

  Therefore, even if φ is not known, by measuring the maximum value r (t) max or the minimum value r (t) min from the output signals of the first detection sensor and the second detection sensor, the variation amount of the width of the identification code ΔL can be calculated from the following equation (10).

  When the distance from the rotational axis of the rotary scale to the detection point of the identification code by the first detection sensor and the second detection sensor is a radius R, the fluctuation amount ΔL of the identification code width is expressed by the following equation (11). Is done.

  Therefore, the eccentricity e of the identification code group with respect to the rotary axis of the rotary scale can be obtained from the variation ΔL of the identification code width.

  As described above, according to the first aspect of the present invention, there is obtained an effect that the eccentric amount of the identification code group with respect to the rotary shaft of the rotary scale can be easily measured.

<Second Aspect of the Present Invention>
According to a second aspect of the present invention, there is provided a rotating mechanism for rotating a rotary scale having a plurality of identification codes arranged at equal intervals on the same circumference to form a group of identification codes with a driving force of a driving force source, and the identification A first detection sensor disposed at a position where the code can be detected, and a second detection sensor disposed at a position where the phase is shifted by 180 degrees with respect to the first detection sensor at a position where the identification code can be detected. And an arithmetic device, wherein the arithmetic device is a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor. And an eccentric phase of the identification code group with respect to a rotary axis of the rotary scale from a rotational phase of the rotary scale when the ratio of the detected pulse widths is a maximum value or a minimum value. A means, and it is eccentric measuring apparatus characterized.

  The second detection sensor is disposed at a position where the phase is shifted by 180 degrees with respect to the first detection sensor at a position where the identification code can be detected. Therefore, in the above equation (4), α = π. In this case, the ratio r (t) between the detection pulse width of the identification code by the first detection sensor and the detection pulse width of the identification code by the second detection sensor becomes the maximum value r (t) max because g (t) = Π / 2, and at this time, the denominator of Equation (4) is minimized.

  Therefore, when the ratio r (t) between the detection pulse width of the identification code by the first detection sensor and the detection pulse width of the identification code by the second detection sensor becomes the maximum value r (t) max, the first detection sensor The detection pulse width of the identification code and the detection pulse width of the identification code by the second detection sensor are the densest on either side and the coarsest on the other side. That is, at this time, the eccentric phase of the identification code group with respect to the rotation axis of the rotary scale is in a state of being coincident with the detection point of the identification code by the first detection sensor or the detection point of the identification code by the second detection sensor. Therefore, from the rotational phase of the rotary scale when the ratio r (t) between the detection pulse width of the identification code by the first detection sensor and the detection pulse width of the identification code by the second detection sensor becomes the maximum value r (t) max. The eccentric phase of the identification code group with respect to the rotation axis of the rotary scale can be obtained.

  On the other hand, when the ratio r (t) between the detection pulse width of the identification code detected by the first detection sensor and the detection pulse width of the identification code detected by the second detection sensor becomes the minimum value r (t) min, the rotation axis of the rotary scale The eccentric phase of the identification code group is 90 degrees out of phase with respect to the detection point of the identification code by the first detection sensor or the detection point of the identification code by the second detection sensor. Therefore, from the rotational phase of the rotary scale when the ratio r (t) between the detection pulse width of the identification code by the first detection sensor and the detection pulse width of the identification code by the second detection sensor becomes the minimum value r (t) min. The eccentric phase of the identification code group with respect to the rotation axis of the rotary scale can be obtained.

  As described above, according to the second aspect of the present invention, there is obtained an operational effect that the eccentric phase of the identification code group with respect to the rotation axis of the rotary scale can be easily measured.

<Third Aspect of the Present Invention>
According to a third aspect of the present invention, there is provided an identification code group in which a driving force source, a rotating body that rotates when the driving force of the driving force source is transmitted, and a plurality of identification codes are arranged at equal intervals on the same circumference. A rotary scale that rotates with the rotating body or the drive shaft of the driving force source, a first detection sensor disposed at a position where the identification code can be detected, and a position where the identification code can be detected. The driving force source is controlled based on a second detection sensor disposed at a position 180 degrees out of phase with the first detection sensor and an output signal of the first detection sensor or the second detection sensor. A control device, and the control device calculates a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor. Means to do , Means for calculating a variation amount of the identification code width detected by the first detection sensor or the second detection sensor from a maximum value or a minimum value of the ratio of the detection pulse widths, and a variation amount of the identification code width. Means for calculating the amount of eccentricity of the identification code group with respect to the rotational axis of the rotary scale, and the rotational axis of the rotary scale from the rotational phase of the rotary scale when the ratio of the detection pulse width becomes the maximum value or the minimum value And a means for correcting a rotation error of the rotating body based on the amount of eccentricity and the eccentric phase.

Here, assuming that N identification codes are arranged at equal intervals on the same circumference to form a rotary scale identification code group, when the rotary scale is rotated by θ ₁ → θ ₂ , the theory Specifically (assuming that the identification code group is not decentered with respect to the rotary axis of the rotary scale), the drive shaft of the driving force source is changed until the identification code of the number S obtained from the following equation (12) is detected. Rotate it.

  However, in reality, since the identification code group is decentered with respect to the rotary shaft of the rotary scale, when the drive shaft of the driving force source is rotated until the identification code of the number S obtained from Equation (12) is detected, The actual rotation angle θ of the rotary scale is expressed by the following equation (13). That is, a rotation error of Δθ occurs (formula (14)).

That is, if the eccentricity e and the eccentricity phase of the identification code group with respect to the rotary axis of the rotary scale are specified, the rotation error Δθ when the rotary scale is rotated by θ ₁ → θ ₂ can be obtained. Thus, the rotation error of the rotating body occurring in the above can be obtained. Therefore, in the rotational phase control of the rotator, the rotation error of the rotator due to the eccentricity of the identification code group with respect to the rotation axis of the rotary scale can be corrected with high accuracy.

  As described above, according to the third aspect of the present invention, in the rotating device using the rotary scale, it is possible to reduce the decrease in the accuracy of the rotational phase control due to the eccentricity of the identification code group with respect to the rotary shaft of the rotary scale. The effect that it can be obtained.

<Fourth aspect of the present invention>
According to a fourth aspect of the present invention, there is provided an identification code group in which a driving force source, a rotating body that rotates when the driving force of the driving force source is transmitted, and a plurality of identification codes are arranged at equal intervals on the same circumference. A rotary scale that rotates with the rotating body or the drive shaft of the driving force source, an identification code detection sensor disposed at a position where the identification code can be detected, and a reference for rotational phase control of the rotating body A reference mark detection sensor disposed at a position where a reference mark attached to the rotary scale as a point can be detected, a control device that controls the driving force source based on an output signal of the identification code detection sensor, The control device includes the information on the amount of eccentricity of the identification code group with respect to the rotary axis of the rotary scale and the eccentric phase of the identification code group with respect to the rotary axis of the rotary scale. A rotating apparatus comprising: a non-volatile storage medium in which information for specifying from a mark is stored in advance; and means for correcting a rotation error of the rotating body based on the eccentricity and the eccentric phase It is.

  The eccentric amount and the eccentric phase of the identification code group with respect to the rotary shaft of the rotary scale are measured in advance, and information on the measured eccentric amount and eccentric phase is stored in advance in a nonvolatile storage medium. Then, similarly to the third aspect of the present invention, the rotation error of the rotating body is corrected based on the eccentric amount and the eccentric phase. Thereby, in the rotational phase control of the rotator, the rotation error of the rotator due to the eccentricity of the identification code group with respect to the rotation axis of the rotary scale can be corrected with high accuracy.

  As described above, according to the fourth aspect of the present invention, in the rotating device using the rotary scale, it is possible to reduce the decrease in the accuracy of the rotational phase control due to the eccentricity of the identification code group with respect to the rotary shaft of the rotary scale. The effect that it can be obtained.

<Fifth aspect of the present invention>
The fifth aspect of the present invention provides an eccentricity measurement for measuring an eccentricity amount of the identification code group with respect to a rotary shaft of a rotary scale in which a plurality of identification codes are arranged at equal intervals on the same circumference to form an identification code group. A method in which a first detection sensor is disposed at a position where the identification code can be detected; and a second phase is shifted from the first detection sensor at a position where the identification code can be detected. A step of providing a detection sensor; a step of rotating the rotary scale around the rotation axis; and a detection pulse width of the identification code by the first detection sensor and detection of the identification code by the second detection sensor. The first detection sensor or the second detection sensor detects the step of calculating the maximum value or minimum value of the ratio to the pulse width and the maximum value or minimum value of the ratio of the detection pulse width. A step of calculating the variation of the width of the serial identification code, said and a step of calculating the amount of eccentricity from the variation amount of the width of the identification code is eccentricity determination method wherein the.
According to the fifth aspect of the present invention, the same operational effects as those of the first aspect of the present invention described above can be obtained.

<Sixth aspect of the present invention>
A sixth aspect of the present invention provides an eccentricity measurement for measuring an eccentric phase of the identification code group with respect to a rotary shaft of a rotary scale in which a plurality of identification codes are arranged at equal intervals on the same circumference to form an identification code group. A method in which a first detection sensor is disposed at a position where the identification code can be detected; and a position which is 180 degrees out of phase with the first detection sensor at a position where the identification code can be detected. A step of disposing a second detection sensor; a step of rotating the rotary scale around the rotation axis; a detection pulse width of the identification code by the first detection sensor; and the identification code by the second detection sensor. A step of calculating a maximum value or a minimum value of the ratio to the detection pulse width of the rotation scale, and a rotation phase of the rotary scale when the ratio of the detection pulse width becomes the maximum value or the minimum value. And a step of calculating the serial eccentricity phase, a is eccentricity determination method wherein the.
According to the sixth aspect of the present invention, the same operational effects as those of the second aspect of the present invention described above can be obtained.

<Seventh aspect of the present invention>
According to a seventh aspect of the present invention, there is provided a discriminating code group in which a driving force source, a rotating body that rotates by transmitting the driving force of the driving force source, and a plurality of identification codes are arranged at equal intervals on the same circumference. A rotary scale that rotates with the rotating body or the driving shaft of the driving force source, a first detection sensor disposed at a position where the identification code can be detected, and an output signal of the first detection sensor And a control device that controls the driving force source based on the second detection method, wherein the second detection device is located at a position where the phase is shifted with respect to the first detection sensor at a position where the identification code can be detected. Disposing a detection sensor; and calculating a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor; , The detection pal A step of calculating a variation amount of the width of the identification code detected by the first detection sensor or the second detection sensor from a maximum value or a minimum value of a width ratio; and the rotary scale from the variation amount of the width of the identification code. And a step of calculating an eccentricity amount of the identification code group with respect to the rotation axis of the rotating shaft, and a step of removing the second detection sensor when the eccentricity amount is within a predetermined range. It is a manufacturing method.

  Since the amount of eccentricity of the identification code group with respect to the rotary axis of the rotary scale varies from individual to individual, there is an extremely small amount of eccentricity in an individual, and therefore it is possible to tolerate a reduction in the accuracy of rotational phase control caused by it. There is also. That is, if the amount of eccentricity of the identification code group with respect to the rotary shaft of the rotary scale is within an allowable range, it may not be necessary to correct the rotation error of the rotating body caused by the eccentricity amount. Therefore, in such a case, since only one sensor is sufficient to detect the identification code of the rotary scale, the second detection sensor is removed. That is, according to the seventh aspect of the present invention, there is an effect that the manufacturing cost of the rotating device can be rationally reduced while maintaining the accuracy of the rotational phase control of the rotating body at a certain level or higher.

<Eighth aspect of the present invention>
According to an eighth aspect of the present invention, there is provided an identification code group in which a driving force source, a rotating body that rotates when the driving force of the driving force source is transmitted, and a plurality of identification codes are arranged at equal intervals on the same circumference. A rotary scale that rotates integrally with the rotating body on the same rotation axis as the rotating body, a detection sensor disposed at a position where the identification code can be detected, and an output signal of the detection sensor A control device for controlling the driving force source based on the method, a method of measuring an eccentric phase of the rotating body with respect to the rotating shaft, and the rotary scale with respect to the rotating shaft. Measuring the eccentric phase of the identification code group, and the rotary phase so that the eccentric phase of the rotating body with respect to the rotating shaft and the eccentric phase of the identification code group of the rotary scale are shifted by 180 degrees. And a step of assembling the scale, and it is a method of manufacturing a rotary apparatus wherein.

  The rotating device manufactured by the manufacturing method is configured such that the rotary scale rotates integrally with the rotating body on the same rotating shaft as the rotating body, and the eccentric phase of the rotating body with respect to the rotating shaft and the identification code group of the rotary scale. The eccentric phase is 180 degrees out of phase. As a result, in the rotating device, the rotation error caused by the eccentricity of the rotating body and the rotation error caused by the eccentricity of the identification code group of the rotary scale are offset, so that the rotation error generated in the rotating body can be extremely reduced. it can. Therefore, according to the eighth aspect of the present invention, in the rotating device using the rotary scale, it is possible to reduce a decrease in the accuracy of the rotational phase control due to the eccentricity of the identification code group with respect to the rotary shaft of the rotary scale. An effect is obtained.

<Ninth aspect of the present invention>
According to a ninth aspect of the present invention, in the method for manufacturing a rotating device according to the eighth aspect, the step of measuring the eccentric phase of the identification code group of the rotary scale with respect to the rotating shaft is the sixth aspect described above. It is a manufacturing method of the rotating apparatus characterized by being the eccentricity measuring method as described in the aspect.
According to the ninth aspect of the present invention, in the method for manufacturing the rotating device according to the eighth aspect described above, the effect of easily measuring the eccentric phase of the identification code group with respect to the rotary shaft of the rotary scale can be obtained. Is obtained.

<Tenth aspect of the present invention>
According to a tenth aspect of the present invention, there is provided a rotating mechanism for rotating a rotary scale having a plurality of identification codes arranged at equal intervals on the same circumference to form a group of identification codes with a driving force of a driving force source, and the identification A first detection sensor disposed at a position where a code can be detected; a second detection sensor disposed at a position where the phase is shifted with respect to the first detection sensor at a position where the identification code can be detected; A control program for causing a computer to control the eccentricity measuring device comprising: a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor. A procedure for calculating a maximum value or a minimum value, and a variation amount of the width of the identification code detected by the first detection sensor or the second detection sensor from the maximum value or the minimum value of the ratio of the detection pulse widths A step of calculating, the procedure for calculating the eccentricity amount of the identification code group with respect to the rotation axis of the rotary scale from the amount of variation of the width of the identification code, to the execution, it is a control program, wherein.
According to the tenth aspect of the present invention, in the eccentricity measuring apparatus configured as described above, which is controlled by a computer capable of executing this control program, the same operational effects as those of the first aspect of the present invention described above can be obtained.

<Eleventh aspect of the present invention>
According to an eleventh aspect of the present invention, there is provided a rotating mechanism for rotating a rotary scale having a plurality of identification codes arranged at equal intervals on the same circumference to form a group of identification codes with a driving force of a driving force source; A first detection sensor disposed at a position where the code can be detected, and a second detection sensor disposed at a position where the phase is shifted by 180 degrees with respect to the first detection sensor at a position where the identification code can be detected. And a control program for causing a computer to execute control of the eccentricity measuring device comprising: a detection pulse width of the identification code by the first detection sensor; and a detection pulse width of the identification code by the second detection sensor. The procedure for calculating the maximum value or the minimum value of the ratio and the rotation of the rotary scale from the rotation phase of the rotary scale when the ratio of the detection pulse width becomes the maximum value or the minimum value. A step of calculating the identification code group of the eccentric phase with respect to the axis, to the execution, it is a control program, wherein.
According to the eleventh aspect of the present invention, in the eccentricity measuring apparatus configured as described above, which is controlled by a computer capable of executing this control program, the same operational effects as those of the second aspect of the present invention described above can be obtained.

<Twelfth aspect of the present invention>
According to a twelfth aspect of the present invention, there is provided an identification code group in which a driving force source, a rotating body that rotates when the driving force of the driving force source is transmitted, and a plurality of identification codes are arranged at equal intervals on the same circumference A rotary scale that rotates with the rotating body or the drive shaft of the driving force source, a first detection sensor disposed at a position where the identification code can be detected, and a position where the identification code can be detected. A control program for causing a computer to execute control of a rotation device including a second detection sensor disposed at a position shifted in phase by 180 degrees with respect to the first detection sensor; From the procedure for calculating the maximum value or the minimum value of the ratio between the detection pulse width of the identification code and the detection pulse width of the identification code by the second detection sensor, and the maximum value or the minimum value of the ratio of the detection pulse width The procedure for calculating the variation amount of the identification code width detected by the first detection sensor or the second detection sensor, and the eccentricity of the identification code group with respect to the rotary shaft of the rotary scale from the variation amount of the identification code width. A procedure for calculating an amount; a procedure for calculating an eccentric phase of the identification code group with respect to a rotary axis of the rotary scale from a rotary phase of the rotary scale when the ratio of the detection pulse widths is a maximum value or a minimum value; And a procedure for correcting a rotation error of the rotating body based on the amount of eccentricity and the eccentric phase.
According to the twelfth aspect of the present invention, the same effect as that of the third aspect of the present invention described above can be obtained in the rotating device configured as described above, which is controlled by a computer capable of executing this control program.

The block diagram of 1st Example of an eccentricity measuring apparatus. The front view which expanded and illustrated a part of rotary scale. The flowchart which illustrated the procedure which measures the eccentric amount of a rotary scale. The block diagram of 2nd Example of an eccentricity measuring apparatus. The flowchart which illustrated the procedure which measures the eccentric phase of a rotary scale. FIG. 3 is a side sectional view illustrating the main part of the ink jet printer. 1 is a schematic block diagram of an inkjet printer. The block diagram of the rotation apparatus of 3rd Example. The flowchart of the measurement procedure of the eccentric amount and eccentric phase of a rotary scale. The flowchart which illustrated the procedure of rotation control of a conveyance drive roller. The block diagram of the rotation apparatus of 4th Example. The flowchart (5th Example) of the manufacturing method of a rotating apparatus. The flowchart of the manufacturing method of a rotating apparatus (6th Example). The principal part block diagram of the rotating apparatus manufactured with the manufacturing method of 6th Example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

<First embodiment>
A first embodiment of the present invention will be described with reference to FIGS. First, the configuration of the rotary scale 2 and the eccentricity measuring device 20 will be described with reference to FIGS. 1 and 2.
FIG. 1 is a configuration diagram of a first embodiment of the eccentricity measuring apparatus 20.

  The rotary scale 2 is a member used for a known rotary encoder. Specifically, the rotary scale 2 is a disk-shaped member, and a circular hole 2a into which the rotating shaft is inserted and fitted is formed in the center. The rotary scale 2 has a plurality of slits SL as “identification codes” arranged at equal intervals on the same circumference to form slit groups as “identification code groups”. Regardless of the distance from the center Cs of the slit group, the slit SL is formed such that the width of the slit SL and the interval between the slits SL are always equal on the same circumference around the center Cs of the slit group. Yes. That is, the slit SL has a shape in which the width increases radially outward from the center Cs side of the slit group.

  The eccentricity measuring device 20 is a device for measuring the amount of eccentricity e of the slit group with respect to the rotation axis of the rotary scale 2, and includes a motor 21, a first detection sensor 22, a second detection sensor 23, and an arithmetic device 24. .

  The motor 21 as a “driving force source” is a DC motor and constitutes a “rotating mechanism” that rotates the rotary scale 2. More specifically, the circular hole 2a of the rotary scale 2 can be fitted to the rotating shaft 211 of the motor 21, and the rotary scale 2 can be rotated by rotating the motor 21 in this state. .

  The first detection sensor 22 is disposed at a position where the slit SL of the rotary scale 2 rotated by the motor 21 can be detected. The second detection sensor 23 is disposed at a position where the slit SL of the rotary scale 2 rotated by the motor 21 can be detected, and the phase is shifted by the phase difference α with respect to the first detection sensor 22. The first detection sensor 22 and the second detection sensor 23 are optical sensors that can detect the slit SL of the rotary scale 2 in a non-contact manner, and each time the slit SL is detected, a pulse signal corresponding to the width of the slit SL. Is output. As a result, the first detection sensor 22 and the second detection sensor 23 output a number of pulse signals having a period corresponding to the rotation speed of the rotary scale 2 corresponding to the rotation amount.

  The arithmetic device 24 having a known microcomputer control circuit includes a ROM 241, a RAM 242, an ASIC (application specific integrated circuit) 243, a CPU (central processing unit) 244, a nonvolatile memory 245, and a motor driver 246. The ROM 241 stores a program for causing the CPU 244 to execute a procedure for measuring an eccentricity e of the rotary scale 2 to be described later. The RAM 242 is used as a work area for the CPU 244 and a data storage area. The ASIC 243 has a control circuit for controlling the rotation of the motor 21, and sends a control signal for the motor 21 to the motor driver 246. The ASIC 243 receives signals output from the first detection sensor 22 and the second detection sensor 23. The CPU 244 executes a program stored in the ROM 241. The nonvolatile memory 245 stores various data necessary for measuring the eccentricity e of the rotary scale 2.

  In the eccentricity measuring apparatus 20 having such a configuration, the center C of the circular hole 2 a of the rotary scale 2 coincides with the axis of the rotating shaft 211 of the motor 21. That is, the center C of the circular hole 2 a of the rotary scale 2 becomes the rotation center of the rotary scale 2. On the other hand, the center Cs of the slit group of the rotary scale 2 is eccentric with respect to the center C within the range of manufacturing tolerances. Therefore, the slit group of the rotary scale 2 is also eccentric with respect to the locus A of the detection points of the first detection sensor 22 and the second detection sensor 23 (a circle having a radius R from the center C, hereinafter referred to as “sensor locus A”). Will do.

  FIG. 2 is an enlarged front view of a part of the rotary scale 2.

  Here, when it is assumed that the center C of the circular hole 2a of the rotary scale 2 and the center Cs of the slit group completely coincide with each other, the sensor locus A is the ideal locus A1, and the center C of the circular hole 2a of the rotary scale 2 is. On the other hand, the sensor locus A when the center Cs of the slit group is decentered by the amount of eccentricity e is defined as an eccentric locus A2. Further, the width of the slit SL in the ideal locus A1 is Lc, and the width of the slit SL in the eccentric locus A2 is L.

  When the difference between the ideal locus A1 and the eccentric locus A2 is maximized, the difference should be equal to the eccentricity e. If the difference between Lc and L at this time (the variation amount of the width of the slit SL) is defined as the variation amount ΔL, the following equation (11) is established as described above.

The width Lc of the slit SL in the ideal locus A1 and the radius R of the sensor locus A are both known values. Therefore, the amount of eccentricity e of the slit group of the rotary scale 2 can be obtained from ΔL.
The above equation (11) is based on the premise that sin θs = θs holds when the width of the slit SL is sufficiently small and the angle difference between the slits SL is θs. This is considered to be true for most rotary scales 2

  FIG. 3 is a flowchart illustrating a procedure for measuring the eccentricity e of the rotary scale 2.

  First, rotation of the rotary scale 2 is started (step S1). The rotational speed of the rotary scale 2 at this time may be an appropriate speed, and even if some rotational fluctuation occurs, there is no problem. Subsequently, the pulse width of the output signal of the first detection sensor 22 is compared with the pulse width of the output signal of the second detection sensor 23, and the maximum value r (t) max or the minimum value r (t) min of the ratio of the two is compared. Is calculated (step S2). Subsequently, the fluctuation amount ΔL of the width of the slit SL is calculated from the maximum value r (t) max or the minimum value r (t) min (step S3). As described above, the fluctuation amount ΔL can be calculated by the following equation (10).

  Then, the amount of eccentricity e of the slit group with respect to the center C of the circular hole 2a of the rotary scale 2 is calculated from the equation (11) (step S4).

  As described above, according to the first embodiment of the present invention, the eccentric amount e of the slit group with respect to the rotation axis of the rotary scale 2 can be easily measured.

<Second embodiment>
A second embodiment of the present invention will be described with reference to FIGS.

FIG. 4 is a configuration diagram of the second embodiment of the eccentricity measuring apparatus 20.
The eccentricity measuring apparatus 20 of this embodiment is different from the first embodiment in that the second detection sensor 23 is disposed at a position that is 180 degrees out of phase with the first detection sensor 22. ing. The other configuration is the same as that of the first embodiment.

FIG. 5 is a flowchart illustrating a procedure for measuring the eccentric phase of the rotary scale 2.
Since the procedure of step S11 and step S12 is the same as step S1 and step S2 of the flowchart (FIG. 3) of the first embodiment, the description thereof is omitted.

  The rotary scale when the ratio between the pulse width of the output signal of the first detection sensor 22 and the pulse width of the output signal of the second detection sensor 23 is the maximum value r (t) max or the minimum value r (t) min. From the rotational phase of 2, the eccentric phase of the slit group with respect to the center C of the circular hole 2a of the rotary scale 2 is calculated (step S13).

  As described above, when the ratio between the pulse width of the output signal of the first detection sensor 22 and the pulse width of the output signal of the second detection sensor 23 is the maximum value r (t) max, the circular hole 2a of the rotary scale 2 is used. The eccentric phase of the slit group with respect to the center C of the slit coincides with the detection point of the slit SL by the first detection sensor 22 and the detection point of the slit SL by the second detection sensor 23. More specifically, when the ratio between the pulse width of the output signal of the first detection sensor 22 and the pulse width of the output signal of the second detection sensor 23 reaches the maximum value r (t) max, the first detection sensor 22 The detection pulse width of the slit SL and the detection pulse width of the slit SL by the second detection sensor 23 are the densest on either side and the coarsest on the other side. The distance from the center C of the circular hole 2a of the rotary scale 2 to the slit SL is the longest at the detection point of the sensor on the side where the detection pulse width of the slit SL is the densest. On the other hand, the distance from the center C of the circular hole 2a of the rotary scale 2 to the slit SL is the shortest at the detection point of the sensor on the side where the detection pulse width of the slit SL is the coarsest.

  On the other hand, when the ratio of the pulse width of the output signal of the first detection sensor 22 to the pulse width of the output signal of the second detection sensor 23 is the minimum value r (t) min, the center C of the circular hole 2a of the rotary scale 2 As for the eccentric phase of the slit group, the phase is shifted by 90 degrees with respect to the detection point of the slit SL by the first detection sensor 22 and the detection point of the slit SL by the second detection sensor 23. Accordingly, the ratio r (t) between the detection pulse width of the slit SL by the first detection sensor 22 and the detection pulse width of the slit SL by the second detection sensor 23 is the minimum value r (t) min. The eccentric phase of the slit group with respect to the center C of the circular hole 2a of the rotary scale 2 can also be obtained from the rotational phase.

  Thus, according to the second embodiment of the present invention, the eccentric phase of the slit group with respect to the rotation axis of the rotary scale 2 can be easily measured.

<Third embodiment>
A third embodiment of the present invention will be described with reference to FIGS. First, a schematic configuration of the ink jet printer 1 will be described with reference to FIGS. 6 and 7.

  FIG. 6 is a side sectional view illustrating the main part of the inkjet printer 1.

  The ink jet printer 1 includes a transport driving roller 11, a transport driven roller 12, a recording paper support member 13, a discharge driving roller 14, a discharge driven roller 15, a carriage 16, and a recording head 17.

  The transport driving roller 11 is formed by applying a high friction coating on the outer peripheral surface of the metal shaft, and rotates by receiving the rotational driving force of the PF motor 31 (FIG. 7). The transport driven roller 12 is pivotally supported so as to be driven to rotate in a state of being biased in a direction in contact with the transport drive roller 11. The recording paper support member 13 is a member that supports the recording paper P in a region where ink is ejected from the recording head 17. The discharge driving roller 14 rotates by receiving the rotational driving force of the PF motor 31 (FIG. 7). The discharge driven roller 15 is pivotally supported so as to be driven to rotate and is urged in a direction in which the discharge driven roller 15 contacts the discharge drive roller 14.

  The carriage 16 is supported so as to be able to reciprocate in the main scanning direction X by a carriage support frame 19 with which a carriage guide shaft 18 inserted into the bearing portion 161 and a supported portion 162 abut. The main scanning direction X is a direction that intersects the sub-scanning direction Y (the conveyance direction of the recording paper P) along the recording surface of the recording paper P supported by the recording paper support member 13. The carriage guide shaft 18 and the carriage support frame 19 are disposed along the main scanning direction X. The carriage 16 is connected to an endless belt (not shown) that rotates in both directions by the rotational driving force of the CR motor 32 (FIG. 7). The endless belt is hung on a driving pulley and a driven pulley (not shown) of the CR motor 32, and is disposed substantially parallel to the carriage guide shaft 18 and the carriage support frame 19. The carriage 16 can be reciprocated in the main scanning direction X by bidirectionally rotating the endless belt with the driving force of the CR motor 32.

  The recording head 17 is mounted on the carriage 16 so that the head surface faces the recording surface of the recording paper P supported by the recording paper support member 13. The head surface of the recording head 17 is provided with a number of ejection nozzles (not shown) for ejecting ink onto the recording surface of the recording paper P to form dots. Ink is supplied to the recording head 17 from an ink tank (not shown) provided in the main body of the inkjet printer 1 via an ink tube (not shown).

  In the inkjet printer 1 having the above-described configuration, the fed recording paper P is supported by the recording paper support member 13 and ink is ejected from the head surface of the recording head 17 that reciprocates in the main scanning direction X. By repeating the main scanning operation in which dots are formed at the same time and the sub-scanning operation in which the dots are transported in the sub-scanning direction Y by a predetermined transport amount, recording is performed on the recording surface. A series of these recording controls are executed by the control device 100 having a known microcomputer control circuit.

FIG. 7 is a schematic block diagram of the inkjet printer 1.
The control device 100 includes a ROM 101, a RAM 102, an ASIC 103, a CPU 104, a nonvolatile memory 105, a PF motor driver 106, a CR motor driver 107, and a head driver 108.

  The ROM 101 stores a recording control program (firmware) and the like necessary for the control of the ink jet printer 1 by the CPU 104. The RAM 102 is used as a work area for the CPU 104 and a storage area for recording data. The ASIC 103 has a control circuit for performing speed control of the PF motor 31 and the CR motor 32 that are DC motors and nozzle drive control of the recording head 17. The ASIC 103 sends the control signal of the PF motor 31 to the PF motor driver 106, the control signal of the CR motor 32 to the CR motor driver 107, and the control signal of the recording head 17 to the head driver 108, respectively. Further, the ASIC 103 has an interface function with the personal computer 200. The CPU 104 performs arithmetic processing for executing recording control of the inkjet printer 1 and other necessary arithmetic processing. The nonvolatile memory 105 stores data necessary for processing the recording control program.

  The ink jet printer 1 further includes a linear encoder 33 and a rotary encoder 34. Output signals from the linear encoder 33 and the rotary encoder 34 are input to the CPU 104 via the ASIC 103. A known linear encoder 33 is an encoder for detecting the position and moving speed of the carriage 16. When the carriage 16 reciprocates in the main scanning direction X, a pulse signal having a period corresponding to the moving speed moves. The number corresponding to the quantity is output. The known rotary encoder 34 is an encoder for detecting the rotation amount of the transport driving roller 11 and the like, and the rotation of the transport driving roller 11 and the discharge driving roller 14 generates a pulse signal having a period corresponding to the rotational speed. A number corresponding to the amount of rotation is output.

Next, the configuration of the rotation device 30 provided in the inkjet printer 1 will be described with reference to FIG.
FIG. 8 is a configuration diagram of the rotation device 30 of the third embodiment.

  The rotating device 30 includes a conveyance driving roller 11 as a “rotating body”, a PF motor 31 as a “driving force source”, a rotary encoder 34, and a control device 100. The rotary encoder 34 includes a rotary scale 2, a first detection sensor 22, and a second detection sensor 23. The configuration of the rotary scale 2 is the same as that described in the first embodiment. The rotary scale 2 is assembled to the transport drive roller 11 in a state where the rotation shaft portion 111 of the transport drive roller 11 is inserted into and fitted into the circular hole 2 a, and rotates together with the transport drive roller 11. The first detection sensor 22 and the second detection sensor 23 are arranged at positions where the slit SL of the rotary scale 2 can be detected, and are sensors having the same configuration as described in the first embodiment. Further, the first detection sensor 22 and the second detection sensor 23 are arranged in a positional relationship that is 180 degrees out of phase as in the second embodiment.

  In the rotating device 30 having such a configuration, the center C of the circular hole 2 a of the rotary scale 2 coincides with the axis of the rotating shaft portion 111 of the transport driving roller 11. That is, the rotation shaft portion 111 of the transport driving roller 11 becomes the rotation center of the rotary scale 2. On the other hand, the center Cs of the slit group of the rotary scale 2 is eccentric with respect to the center C within the range of manufacturing tolerances. Therefore, the slit group of the rotary scale 2 is also eccentric with respect to the sensor locus A.

FIG. 9 is a flowchart illustrating a procedure for measuring the eccentricity e and the eccentricity phase of the rotary scale 2.
Since the procedure from step S21 to step S24 is the same as that from step S1 to step S4 in the flowchart (FIG. 3) of the first embodiment, a description thereof will be omitted. Moreover, since the procedure of step 25 is the same as step S13 of the flowchart (FIG. 5) of the second embodiment, the description thereof is omitted.
Note that the procedure of the flowchart may be executed only when the ink jet printer 1 is turned on or immediately after the control device 100 is reset.

FIG. 10 is a flowchart illustrating a procedure for controlling the rotation of the transport drive roller 11.
The control device 100 corrects the rotation error of the transport drive roller 11 due to the eccentricity based on the eccentricity e and the eccentric phase of the slit group of the rotary scale 2 with respect to the rotation shaft portion 111 of the transport drive roller 11. Suppose that the total number of slits SL of the rotary scale 2 is N, and the rotary scale 2 is rotated by θ ₁ → θ ₂ .

First, when the rotary scale is rotated by θ ₁ → θ ₂ , a rotation error caused by the eccentricity of the slit group with respect to the center C of the circular hole 2 a of the rotary scale 2 is obtained, and the rotation error is a unit of the rotary scale 2. It is determined whether or not the rotation angle (the rotation angle corresponding to the pitch of the slits SL and the minimum rotation angle of the rotary scale 2) is not reached (step S31). More specifically, the determination is made based on whether or not the following formula (15) holds.

The left side of equation (15) is the unit rotation angle of the rotary scale 2 with the number of slits N, and the right side of equation (15) is the rotation error (Δθ) obtained from equation (14) described above.
In step S31, it may be determined whether the rotation error is less than ½ of the unit rotation angle of the rotary scale 2. In this case, the 2π / N portion in the above equation (15) may be changed to π / N.

  If the rotation error is less than the unit rotation angle of the rotary scale 2 (Yes in step S31), the procedure is terminated without correcting the rotation error. On the other hand, when the rotation error is equal to or greater than the unit rotation angle of the rotary scale 2 (No in step S31), the number k of slits SL (hereinafter referred to as “correction slit number k”) corresponding to the rotation error is calculated. (Step S32). More specifically, the correction slit number k is obtained by the following equation (16).

  Here, the correction slit number k needs to be an integer. For example, an integer obtained by rounding down or rounding up the calculated value according to equation (16) may be used as the correction slit number k, but an integer obtained by rounding off the decimal value of the calculated value according to equation (16) is the correction slit number. If it is set to k, it becomes possible to obtain | require the integer value which approximates more, and it is preferable at the point which can correct | amend the rotation error of the conveyance drive roller 11 more highly accurately.

  Subsequently, the number of slits SL (hereinafter referred to as “the number of conveying slits S”) corresponding to the corrected rotation amount is calculated (step S33). The number S of conveyance slits can be calculated | required by the following formula | equation (17).

  And the conveyance drive roller 11 is rotated until the slit SL of the conveyance slit number S is detected by the 1st detection sensor 22 or the 2nd detection sensor 23. FIG. Thereby, it is possible to correct the rotation error due to the eccentricity of the slit group of the rotary scale 2 with respect to the rotation shaft portion 111 of the transport driving roller 11 with high accuracy.

  As described above, according to the third embodiment of the present invention, in the rotating device 30 using the rotary scale 2, a reduction in the accuracy of the rotational phase control due to the eccentricity of the slit group with respect to the rotating shaft of the rotary scale 2 is reduced. be able to.

<Fourth embodiment>
A fourth embodiment of the present invention will be described with reference to FIG.
FIG. 11 is a configuration diagram of the rotating device 30 of the fourth embodiment.

  Similar to the third embodiment, the rotating device 30 of the fourth embodiment includes a transport driving roller 11, a PF motor 31, a rotary encoder 34, and a control device 100 that constitute the inkjet printer 1. The rotary encoder 34 of the fourth embodiment has a rotary scale 2, a first detection sensor 22 as a “identification code detection sensor”, and a reference mark detection sensor 25. The rotary scale 2 and the first detection sensor 22 are the same as those in the third embodiment. The reference mark detection sensor 25 is provided to detect a reference mark B that is a reference point for rotational phase control of the rotary scale 2. The reference mark detection sensor 25 is an optical sensor that can detect the reference mark B in a non-contact manner, and is disposed at a position where the reference mark B attached to the rotary scale 2 can be detected. An output signal of the reference mark detection sensor 25 is input to the control device 100.

  In the fourth embodiment, before assembling the rotary scale 2 to the ink jet printer 1, the eccentricity e of the slit group with respect to the center C of the circular hole 2 a of the rotary scale 2 by the eccentricity measuring device 20 of the first embodiment described above. And the numerical data of the measured eccentricity e is stored in the nonvolatile memory 105 of the control device 100. Further, the eccentricity measuring device 20 of the second embodiment described above measures the eccentric phase of the rotary scale 2 and attaches a reference mark B as a mark of the eccentric phase of the rotary scale 2. More specifically, for example, a reference mark B is attached to a portion where the distance from the center C of the circular hole 2a of the rotary scale 2 to the slit SL is the longest. Then, the rotary scale 2 is assembled to the ink jet printer 1.

  The control device 100 can specify the amount of eccentricity e of the slit group of the rotary scale 2 relative to the rotation shaft portion 111 of the transport driving roller 11 from the numerical data of the amount of eccentricity e stored in advance in the nonvolatile memory 105. The eccentric phase of the slit group of the rotary scale 2 can be specified from the rotational phase of the rotary scale 2 in a state where the reference mark detection sensor 25 detects the reference mark B. Therefore, the control apparatus 100 corrects the rotation error due to the eccentricity of the slit group of the rotary scale 2 with respect to the rotation shaft portion 111 of the transport driving roller 11 with high accuracy by the procedure of the flowchart of FIG. 10 described in the third embodiment. be able to.

  As described above, according to the fourth embodiment of the present invention, in the rotating device 30 using the rotary scale 2, reduction in the accuracy of the rotational phase control due to the eccentricity of the slit group with respect to the rotating shaft of the rotary scale 2 is reduced. be able to.

<Fifth embodiment>
A fifth embodiment of the present invention will be described with reference to FIG. The fifth embodiment is a method for manufacturing the rotating device 30.
FIG. 12 is a flowchart illustrating each process of the manufacturing method of the rotating device 30 in time series.

  In the manufacturing process of the ink jet printer 1 (FIGS. 6 and 7), the rotating device 30 (FIG. 8) of the third embodiment is first completed. Subsequently, the procedure of Steps S <b> 41 to Step 44 is executed to measure the eccentricity e of the slit group of the rotary scale 2 with respect to the rotation shaft portion 111 of the transport driving roller 11. Since the procedure of step S41 to step 44 is the same as step S1 to step S4 of the flowchart (FIG. 3) of the first embodiment, the description thereof will be omitted.

  Subsequently, it is determined whether or not the measured eccentricity e is within an allowable range (step S45). The allowable range of the eccentricity e may be set such that, for example, the conveyance error of the recording paper P caused by the rotation error of the conveyance drive roller 11 caused by the eccentricity is within the allowable range in the specification of the ink jet printer 1. . In other words, in order to maintain the conveyance error amount of the recording paper P within the allowable range in the specification of the inkjet printer 1, it is theoretically or experimentally determined how much eccentricity e is allowed. It ’s fine.

  If the measured eccentricity e is not within the allowable range (No in step S45), the procedure is terminated as it is. In this case, the rotation device 30 of the inkjet printer 1 has the same configuration as the rotation device 30 of the third embodiment.

  On the other hand, when the measured eccentricity e is within the allowable range (Yes in step S45), the second detection sensor 23 is removed (step S46). That is, when the eccentricity e is within the allowable range, the rotation error of the transport driving roller 11 caused by the eccentricity is not corrected, and the unnecessary second detection sensor 23 is removed accordingly. To do. Thereby, the manufacturing cost (component cost) of the rotating device 30 of the ink jet printer 1 can be reduced by the amount by which the second detection sensor 23 is removed.

  In addition, when the second detection sensor 23 is removed, the control device 100 is configured so that it can be identified, and the eccentric amount e and the eccentric phase of the slit group of the rotary scale 2 with respect to the rotation shaft portion 111 of the transport driving roller 11 are determined. The procedure for measuring (FIG. 9) and the procedure for correcting the rotation error of the transport driving roller 11 based on the eccentricity e and the eccentric phase (FIG. 10) may not be executed. As a method for causing the control device 100 to identify the presence or absence of the second detection sensor 23, for example, the presence or absence of a pulse signal from the second detection sensor 23 when the transport driving roller 11 is rotated may be identified. Or you may provide the contact input circuit which can set the presence or absence of the 2nd detection sensor 23. FIG.

  Thus, according to the fifth embodiment of the present invention, the manufacturing cost of the rotating device 30 of the ink jet printer 1 can be reasonably reduced while maintaining the accuracy of the rotational phase control of the transport drive roller 11 at a certain level or higher. be able to.

<Sixth embodiment>
A sixth embodiment of the present invention will be described with reference to FIGS. The sixth embodiment is a method for manufacturing the rotating device 30.
FIG. 13 is a flowchart illustrating each process of the manufacturing method of the rotating device 30 in time series. FIG. 14 is a main part configuration diagram of the rotating device 30 manufactured by the manufacturing method of the sixth embodiment.

  In the manufacturing process of the ink jet printer 1 (FIGS. 6 and 7), first, the eccentric phase D1 of the transport drive roller 11 with respect to the rotating shaft 111 is measured (step S51). The eccentric phase D1 of the conveyance drive roller 11 with respect to the rotation shaft portion 111 is, for example, a known variation in the outer peripheral surface of the conveyance drive roller 11 in a state where the conveyance drive roller 11 is rotated about the rotation shaft portion 111 as a rotation center. It can be measured by measuring with a laser displacement meter or a measuring instrument capable of real-time monitoring.

  Subsequently, the eccentric phase D2 of the rotary scale 2 is measured (step S52). The eccentric phase D2 of the rotary scale 2 can be measured by, for example, the eccentricity measuring device 20 of the second embodiment described above.

  Then, the rotary scale 2 is assembled so that the eccentric phase D1 of the transport driving roller 11 and the eccentric phase D2 of the rotary scale 2 have a 180 ° phase shift (step S53). More specifically, a portion where the distance from the rotation shaft portion 111 of the transport driving roller 11 to the outer peripheral surface is the longest, and a portion where the distance from the center C of the circular hole 2a of the rotary scale 2 to the slit SL is the longest. The rotary scale 2 is assembled to the rotating shaft portion 111 of the transport drive roller 11 so that they are in a positional relationship that is opposite by 180 degrees (FIG. 14).

  In the rotating device 30 manufactured by such a manufacturing method, the rotation error caused by the eccentricity of the conveyance drive roller 11 and the rotation error caused by the eccentricity of the slit group of the rotary scale 2 are canceled out. 11 can be made extremely small. Therefore, the first detection sensor 22 is sufficient as a detection sensor provided for detecting the slit SL of the rotary scale 2.

  As described above, according to the sixth embodiment of the present invention, in the rotating device 30 using the rotary scale 2, a reduction in the accuracy of the rotational phase control due to the eccentricity of the slit group with respect to the rotating shaft of the rotary scale 2 is reduced. be able to.

2 Rotary Scale, 2a Rotary Scale Circular Hole, 11 Conveyance Driving Roller, 20 Eccentricity Measuring Device, 21 Motor, 22 First Detection Sensor, 23 Second Detection Sensor, 24 Arithmetic Device, 25 Reference Mark Detection Sensor, 30 Rotation Device, 34 Rotary encoder, 100 Control device, 111 Rotating shaft of transport roller, 211 Rotating shaft of motor, A sensor locus, A1 ideal locus, A2 eccentric locus, B reference mark, C Center of circular hole of rotary scale, Cs slit Center of the group, D1 Eccentric phase of the transport drive roller, D2 Eccentric phase of the rotary scale, e Eccentricity of the rotary scale, L Width of the slit in the eccentric locus, Lc Slit width in the ideal locus, Radius of the R sensor locus, SL Rotary Scale Lit, the phase difference α detection sensor, the amount of variation of the width of the ΔL slit

Claims (12)

A rotation mechanism that rotates a rotary scale in which a plurality of identification codes are arranged at equal intervals on the same circumference to form a group of identification codes with a driving force of a driving force source;
A first detection sensor disposed at a position where the identification code can be detected;
A second detection sensor disposed at a position where the phase is shifted with respect to the first detection sensor at a position where the identification code can be detected;
An arithmetic device,
The computing device computes a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor;
Means for calculating a variation amount of the width of the identification code detected by the first detection sensor or the second detection sensor from the maximum value or the minimum value of the ratio of the detection pulse widths;
Means for calculating an eccentric amount of the identification code group with respect to a rotation axis of the rotary scale from a variation amount of the width of the identification code. A rotation mechanism that rotates a rotary scale in which a plurality of identification codes are arranged at equal intervals on the same circumference to form a group of identification codes with a driving force of a driving force source;
A first detection sensor disposed at a position where the identification code can be detected;
A second detection sensor disposed at a position 180 degrees out of phase with the first detection sensor at a position where the identification code can be detected;
An arithmetic device,
The computing device computes a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor;
Means for calculating an eccentric phase of the identification code group with respect to a rotation axis of the rotary scale from a rotation phase of the rotary scale when the ratio of the detection pulse widths is a maximum value or a minimum value. Eccentricity measuring device. A driving force source,
A rotating body that rotates when the driving force of the driving force source is transmitted;
A plurality of identification codes are arranged at equal intervals on the same circumference to form an identification code group, and a rotary scale that rotates together with the drive shaft of the rotating body or the driving force source,
A first detection sensor disposed at a position where the identification code can be detected;
A second detection sensor disposed at a position 180 degrees out of phase with the first detection sensor at a position where the identification code can be detected;
A control device for controlling the driving force source based on an output signal of the first detection sensor or the second detection sensor,
The control device calculates a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor;
Means for calculating a variation amount of the width of the identification code detected by the first detection sensor or the second detection sensor from the maximum value or the minimum value of the ratio of the detection pulse widths;
Means for calculating the amount of eccentricity of the identification code group with respect to the rotation axis of the rotary scale from the variation amount of the width of the identification code;
Means for calculating an eccentric phase of the identification code group with respect to a rotation axis of the rotary scale from a rotation phase of the rotary scale when the ratio of the detection pulse widths is a maximum value or a minimum value;
Means for correcting a rotation error of the rotating body based on the amount of eccentricity and the eccentric phase. A driving force source,
A rotating body that rotates when the driving force of the driving force source is transmitted;
A plurality of identification codes are arranged at equal intervals on the same circumference to form an identification code group, and a rotary scale that rotates together with the drive shaft of the rotating body or the driving force source,
An identification code detection sensor disposed at a position where the identification code can be detected;
A reference mark detection sensor disposed at a position where a reference mark attached to the rotary scale serving as a reference point for rotational phase control of the rotating body can be detected;
A control device for controlling the driving force source based on an output signal of the identification code detection sensor,
The control device stores in advance information on the amount of eccentricity of the identification code group with respect to the rotary axis of the rotary scale and information for specifying the eccentric phase of the identification code group with respect to the rotary axis of the rotary scale from the reference mark. A non-volatile storage medium,
Means for correcting a rotation error of the rotating body based on the amount of eccentricity and the eccentric phase. An eccentricity measuring method for measuring an eccentricity amount of the identification code group with respect to a rotary shaft of a rotary scale in which a plurality of identification codes are arranged at equal intervals on the same circumference to form an identification code group,
Disposing a first detection sensor at a position where the identification code can be detected;
Disposing a second detection sensor at a position where the phase is shifted with respect to the first detection sensor at a position where the identification code can be detected;
Rotating the rotary scale around the rotation axis;
Calculating a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor;
Calculating a variation amount of the width of the identification code detected by the first detection sensor or the second detection sensor from the maximum value or the minimum value of the ratio of the detection pulse widths;
And a step of calculating the amount of eccentricity from the amount of fluctuation of the width of the identification code. An eccentricity measuring method for measuring an eccentric phase of the identification code group with respect to a rotary shaft of a rotary scale in which a plurality of identification codes are arranged at equal intervals on the same circumference to form an identification code group,
Disposing a first detection sensor at a position where the identification code can be detected;
Disposing a second detection sensor at a position that is 180 degrees out of phase with the first detection sensor at a position where the identification code can be detected;
Rotating the rotary scale around the rotation axis;
Calculating a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor;
Calculating the eccentric phase from the rotational phase of the rotary scale when the ratio of the detected pulse widths becomes the maximum value or the minimum value. A driving force source,
A rotating body that rotates when the driving force of the driving force source is transmitted;
A plurality of identification codes are arranged at equal intervals on the same circumference to form an identification code group, and a rotary scale that rotates together with the drive shaft of the rotating body or the driving force source,
A first detection sensor disposed at a position where the identification code can be detected;
A control device that controls the driving force source based on an output signal of the first detection sensor;
Disposing a second detection sensor at a position where the phase is shifted with respect to the first detection sensor at a position where the identification code can be detected;
Calculating a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor;
Calculating a variation amount of the width of the identification code detected by the first detection sensor or the second detection sensor from the maximum value or the minimum value of the ratio of the detection pulse widths;
Calculating the amount of eccentricity of the identification code group with respect to the rotation axis of the rotary scale from the amount of variation in the width of the identification code;
And a step of removing the second detection sensor when the amount of eccentricity is within a predetermined range. A driving force source,
A rotating body that rotates when the driving force of the driving force source is transmitted;
A plurality of identification codes are arranged at equal intervals on the same circumference to form an identification code group, and a rotary scale that rotates integrally with the rotating body on the same rotation axis as the rotating body,
A detection sensor disposed at a position where the identification code can be detected;
A control device that controls the driving force source based on an output signal of the detection sensor;
Measuring an eccentric phase of the rotating body with respect to the rotating shaft;
Measuring an eccentric phase of the identification code group of the rotary scale relative to the rotation axis;
Assembling the rotary scale so that the eccentric phase of the rotating body with respect to the rotating shaft and the eccentric phase of the identification code group of the rotary scale are shifted by 180 degrees. Device manufacturing method.   9. The method of manufacturing a rotating device according to claim 8, wherein the step of measuring the eccentric phase of the identification code group of the rotary scale with respect to the rotating shaft is the eccentricity measuring method according to claim 6. Method for manufacturing a rotating device. A rotation mechanism that rotates a rotary scale in which a plurality of identification codes are arranged at equal intervals on the same circumference to form a group of identification codes with a driving force of a driving force source;
A first detection sensor disposed at a position where the identification code can be detected;
A control program for causing a computer to execute control of an eccentricity measuring device including a second detection sensor disposed at a position where the phase is shifted with respect to the first detection sensor at a position where the identification code can be detected. And
A procedure for calculating a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor;
Calculating a variation amount of the width of the identification code detected by the first detection sensor or the second detection sensor from the maximum value or the minimum value of the ratio of the detection pulse widths;
And a procedure for calculating an eccentricity amount of the identification code group with respect to a rotation axis of the rotary scale from a variation amount of the width of the identification code. A rotation mechanism that rotates a rotary scale in which a plurality of identification codes are arranged at equal intervals on the same circumference to form a group of identification codes with a driving force of a driving force source;
A first detection sensor disposed at a position where the identification code can be detected;
A control program for causing a computer to execute control of an eccentricity measuring device comprising: a second detection sensor disposed at a position where the phase of the identification code can be detected by 180 degrees with respect to the first detection sensor. Because
A procedure for calculating a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor;
A step of calculating an eccentric phase of the identification code group with respect to a rotation axis of the rotary scale from a rotation phase of the rotary scale when the ratio of the detection pulse widths is a maximum value or a minimum value. Control program. A driving force source,
A rotating body that rotates when the driving force of the driving force source is transmitted;
A plurality of identification codes are arranged at equal intervals on the same circumference to form an identification code group, and a rotary scale that rotates together with the drive shaft of the rotating body or the driving force source,
A first detection sensor disposed at a position where the identification code can be detected;
A control program that causes a computer to execute control of a rotation device that includes a second detection sensor disposed at a position that is 180 degrees out of phase with respect to the first detection sensor at a position where the identification code can be detected. There,
A procedure for calculating a maximum value or a minimum value of a ratio between a detection pulse width of the identification code by the first detection sensor and a detection pulse width of the identification code by the second detection sensor;
Calculating a variation amount of the width of the identification code detected by the first detection sensor or the second detection sensor from the maximum value or the minimum value of the ratio of the detection pulse widths;
A procedure for calculating the amount of eccentricity of the identification code group with respect to the rotation axis of the rotary scale from the variation amount of the width of the identification code;
A procedure for calculating an eccentric phase of the identification code group with respect to a rotation axis of the rotary scale from a rotation phase of the rotary scale when the ratio of the detection pulse width is a maximum value or a minimum value;
And a procedure for correcting a rotation error of the rotating body based on the eccentric amount and the eccentric phase.

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