JP4289923B2 - Motor control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for performing servo control based on a digital encoder signal, for example, a digital encoder control technique suitable for application to a positioning servo for controlling a feed position in paper feed control of an ink jet recording apparatus.
[0002]
[Prior art]
Inkjet recording devices are widely used as a means to record images (including characters and symbols) on recording media such as paper and plastic thin plates (OHP, etc.) based on image information by mounting them on printers, fax machines, and copying machines. Has been.
[0003]
An ink jet recording apparatus performs recording by ejecting ink droplets from a print head onto a recording medium. The recording means can be easily made compact, high-accuracy images can be recorded at high speed, and running cost is low. It is inexpensive and has a feature of low noise due to the non-impact method. In addition, there is an advantage that it is easy to record a color image using multicolor inks.
[0004]
As a drive source of the ink jet recording apparatus, a carriage motor that reciprocates a carriage mounted with a print head, an ASF motor that feeds a recording medium, a recovery system motor that performs head cleaning, and a paper feed that sends the recording medium for each print scan There are motors. Conventionally, stepping motors are often used as the drive source for reasons such as easy cost reduction and simple control.
[0005]
Since the ink jet recording apparatus is a non-impact method, noise is low. However, the use of a DC motor for the drive source has been increased for the purpose of further noise reduction. In this case, an encoder is generally used to obtain DC motor control information.
[0006]
FIG. 1 shows a model diagram of the encoder. In the encoder, the detector 103 detects the light generated from the LED 101 through the code wheel 102 and generates a signal. On the code wheel 102, a portion 104 that transmits light and a portion 105 that does not transmit light are arranged at a predetermined interval. Photodiodes 106, 107, 108 and 109 are arranged at a predetermined interval on the detector 103, and the light detected by each of the photodiodes 106, 107, 108 and 109 is converted into an electric signal A (110) and an electric signal * A. (111), electric signal B (112), converted into electric signal * B (113) and output, and the output electric signals 110, 111, 112, 113 are output by the comparators 114, 115 as differential output Channel A (116). ), Channel B (117).
[0007]
FIG. 2 shows a differential output signal waveform. A signal that is inverted at the intersection of the electric signal A (110) and the electric signal * A (111) is Channel A (116). Here, when the speed is constant, the duty of Channel A (116) is ideally 50%. However, the duty changes due to various factors. One of the major factors is a difference in sensitivity of the photodiode.
[0008]
FIG. 3 shows a differential output signal waveform when there is a difference in photodiode sensitivity. The sensitivity of a photodiode appears as an amplitude difference between electrical signals. FIG. 3 shows Channel A (116) when the amplitude of the electric signal A (110) is smaller than the electric signal * A (111). From the figure, it can be seen that the sensitivity difference of the photodiode changes the duty ratio of the output signal. However, it does not affect the period of Channel A. For the reasons described above, the encoder output signal is generally most accurate in one cycle.
[0009]
When obtaining position information and speed information from an encoder signal as DC motor control information, in order to obtain more accurate information, a one-edge sampling method is generally used in which, for example, a period from the rising edge to the rising edge of the output signal is counted and used. .
[0010]
[Patent Document 1]
JP 2002-034274 A.
[0011]
[Problems to be solved by the invention]
However, the inkjet recording apparatus has been improved in printing resolution, and the motor is required to perform stop control at higher resolution. It is becoming difficult to satisfy the required performance only with the single-edge sampling method that is easy to obtain accuracy. Therefore, there is a need for technology that makes full use of information on both edges, which is more difficult to obtain.
[0012]
As described above, the accuracy of both-phase and double-edge information is lower than that of the single-edge sampling method in principle, but the limit value of component variation is within the required accuracy of the entire printing system. If so, it is not impossible to use. A configuration capable of satisfying the required accuracy of the entire recording apparatus system can be realized if the influence of the drawbacks of both-phase both-edge information can be suppressed as low as possible while using both-phase both-edges.
[0013]
Information obtained from the encoder includes position information used for position servo (hereinafter referred to as position information in servo control), speed information used for speed minor loops in position servo, and stop when the stop position is reached. It is used for three pieces of position information related to control activation timing (hereinafter referred to as position information in stop control).
[0014]
Focusing on the position information in the servo control here, due to the influence of deterioration of both-phase and double-edge information due to component variations, an ink jet recording apparatus in which components with good precision are mounted and an ink jet recording apparatus in which components with poor accuracy are mounted This makes a difference in control performance. As a mass-produced industrial product, even if poor precision parts are used, the performance of the entire product must be guaranteed, which is a problem.
[0015]
Therefore, the present invention has been made in view of the above-described problems, and an object thereof is to enable highly accurate motor control while using both-phase / both-edge information of the encoder.
[0016]
[Means for Solving the Problems]
In order to solve the above-described problems and achieve the object, a motor control device according to the present invention is a motor control device for controlling rotation of a motor, and has a predetermined frequency corresponding to the driving speed of the motor. A first frequency signal generating means for generating a first pulse signal; and a second frequency signal for generating a second pulse signal having a phase difference of about 90 degrees from the first pulse signal at the predetermined frequency. Generating means; detection means capable of independently detecting four types of edges, rising edge and falling edge of the first pulse signal; and rising edge and falling edge of the second pulse signal; and Control means for controlling the rotational position of the motor based on the detection result of the detection means, the same as the edge corresponding to the stop target position of the motor among the four types of edges. Using only the type of the edge, characterized by comprising a control means for performing a rotational position control of the motor between the motor until it is stopped at the target stop position.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described.
[0018]
First, an outline of this embodiment will be described.
[0019]
The present embodiment includes a driving means, a frequency signal generating means for generating a pulse signal having a frequency corresponding to the driving speed of a driven body driven by the driving means, and an edge for detecting the rising and falling edges of the pulse signal. A first frequency signal generating means for generating a first pulse signal having a frequency corresponding to a driving speed of a driven body driven by the driving means and an electrical angle from the first pulse signal; Second frequency signal generating means for generating a second pulse signal having a phase shift of about 90 degrees, a rising edge and a falling edge of the first pulse signal, and a rising edge and a falling edge of the second pulse signal. A control unit that has detection means that can be detected independently and means that adds the information of the four types of edges and employs the information as position information, and performs position servo processing using the position information In the position servo process, the four types of edges can be adopted as the stop position, and in the position servo process, control is performed using only the same type of edge as the edge used for the stop position. The motor control means characterized by this is adopted.
[0020]
The motor control device according to the present embodiment is a motor control device for controlling the rotation of the motor, and generates a first frequency signal that generates a first pulse signal having a predetermined frequency corresponding to the driving speed of the motor. Means, second frequency signal generating means for generating a second pulse signal that is approximately 90 degrees out of phase with the first pulse signal at the predetermined frequency, a rising edge of the first pulse signal, and Detection means capable of independently detecting a falling edge and four types of edges, that is, a rising edge and a falling edge of the second pulse signal, and rotational position control of the motor based on the detection result of the detection means Control means for performing the stopping of the motor using only the same type of edge as the edge corresponding to the stop target position of the motor among the four types of edges. Characterized by comprising a control means for the motor controlling the rotational position of the until stopping at the target position.
[0021]
The motor device control method of the present embodiment includes a motor, first frequency signal generating means for generating a first pulse signal having a predetermined frequency corresponding to the driving speed of the motor, and the predetermined frequency. A second frequency signal generating means for generating a second pulse signal that is about 90 degrees out of phase with the first pulse signal; a rising edge and a falling edge of the first pulse signal; A control method for a motor device for controlling a motor device comprising detection means capable of independently detecting four types of edges, that is, a rising edge and a falling edge of the pulse signal, and a detection result of the detection means In performing the rotational position control of the motor based on the above, only the edge of the same type as the edge corresponding to the stop target position of the motor is used among the four types of edges. , And performing a rotational position control of the motor between the motor until it is stopped at the target stop position.
[0022]
In addition, the program according to the present embodiment causes a computer to execute the above-described motor device control method.
[0023]
The storage medium according to the present embodiment stores the above-described program so as to be readable by a computer.
[0024]
Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings.
[0025]
In the embodiment described below, a recording apparatus using a recording head according to an ink jet method will be described as an example.
[0026]
In this specification, “recording” (sometimes referred to as “printing”) is not only for forming significant information such as characters and figures, but also for human beings visually perceived regardless of significance. Regardless of whether or not it has been manifested, it also represents a case where an image, a pattern, a pattern, or the like is widely formed on a recording medium or the medium is processed.
[0027]
“Recording medium” refers not only to paper used in general recording apparatuses but also widely to cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. Shall.
[0028]
Furthermore, “ink” (sometimes referred to as “liquid”) is to be interpreted broadly in the same way as the definition of “recording (printing)” above. It represents a liquid that can be used for forming a pattern or the like, processing a recording medium, or processing an ink (for example, solidification or insolubilization of a colorant in ink applied to the recording medium).
[0029]
Furthermore, unless otherwise specified, the “nozzle” collectively refers to an ejection port or a liquid channel communicating with the ejection port and an element that generates energy used for ink ejection.
[0030]
<Description of Inkjet Recording Device (FIG. 4)>
FIG. 4 is an external perspective view showing an outline of the configuration of the inkjet recording apparatus 1 which is a typical embodiment of the present invention.
[0031]
As shown in FIG. 4, an ink jet recording apparatus (hereinafter referred to as a recording apparatus) transmits a driving force generated by a carriage motor M1 to a carriage 2 on which a recording head 3 that performs recording by discharging ink according to an ink jet system is mounted. 4, the carriage 2 is reciprocated in the direction of arrow A, and for example, a recording medium P such as recording paper is fed through a paper feeding mechanism 5 and conveyed to a recording position. Recording is performed by ejecting ink onto the recording medium P.
[0032]
Further, in order to maintain the state of the recording head 3 satisfactorily, the carriage 2 is moved to the position of the recovery device 10 and the ejection recovery process of the recording head 3 is intermittently performed.
[0033]
In addition to mounting the recording head 3 on the carriage 2 of the recording apparatus 1, an ink cartridge 6 for storing ink to be supplied to the recording head 3 is mounted. The ink cartridge 6 is detachable from the carriage 2.
[0034]
The recording apparatus 1 shown in FIG. 4 can perform color recording. For this reason, the carriage 2 contains four inks containing magenta (M), cyan (C), yellow (Y), and black (K) inks, respectively. An ink cartridge is installed. These four ink cartridges are detachable independently.
[0035]
Now, the carriage 2 and the recording head 3 can achieve and maintain a required electrical connection by properly contacting the joint surfaces of both members. The recording head 3 applies energy according to a recording signal to selectively eject ink from a plurality of ejection ports for recording. In particular, the recording head 3 of this embodiment employs an ink jet system that ejects ink using thermal energy, and includes an electrothermal transducer to generate thermal energy, which is applied to the electrothermal transducer. Electric energy is converted into thermal energy, and ink is ejected from the ejection port by utilizing pressure changes caused by bubble growth and contraction caused by film boiling caused by applying the thermal energy to the ink. The electrothermal transducer is provided corresponding to each of the ejection ports, and ink is ejected from the corresponding ejection port by applying a pulse voltage to the corresponding electrothermal transducer in accordance with the recording signal.
[0036]
As shown in FIG. 4, the carriage 2 is connected to a part of the driving belt 7 of the transmission mechanism 4 that transmits the driving force of the carriage motor M <b> 1, and slides in the direction of arrow A along the guide shaft 13. It is guided and supported freely. Accordingly, the carriage 2 reciprocates along the guide shaft 13 by forward and reverse rotations of the carriage motor M1. A scale 8 is provided for indicating the absolute position of the carriage 2 along the direction of movement of the carriage 2 (the direction of arrow A). In this embodiment, the scale 8 uses a transparent PET film with black bars printed at a necessary pitch, one of which is fixed to the chassis 9 and the other is supported by a leaf spring (not shown). Yes.
[0037]
Further, the recording apparatus 1 is provided with a platen (not shown) facing the discharge port surface where the discharge port (not shown) of the recording head 3 is formed, and the recording head 3 is driven by the driving force of the carriage motor M1. At the same time as the carriage 2 loaded with is reciprocated, recording is performed over the entire width of the recording medium P conveyed on the platen by giving a recording signal to the recording head 3 and discharging ink.
[0038]
Further, in FIG. 4, 14 is a transport roller driven by a transport motor M2 to transport the recording medium P, 15 is a pinch roller that abuts the recording medium P against the transport roller 14 by a spring (not shown), and 16 is a pinch. A pinch roller holder 17 that rotatably supports the roller 15 is a conveyance roller gear fixed to one end of the conveyance roller 14. Then, the transport roller 14 is driven by the rotation of the transport motor M2 transmitted to the transport roller gear 17 through an intermediate gear (not shown).
[0039]
Further, reference numeral 20 denotes a discharge roller for discharging the recording medium P on which an image is formed by the recording head 3 to the outside of the recording apparatus, and is driven by transmitting the rotation of the transport motor M2. . The discharge roller 20 abuts on a spur roller (not shown) that presses the recording medium P by a spring (not shown). Reference numeral 22 denotes a spur holder that rotatably supports the spur roller.
[0040]
Further, as shown in FIG. 4, the recording apparatus 1 has a desired position (for example, a home position) outside the range of reciprocating motion (outside the recording area) for the recording operation of the carriage 2 on which the recording head 3 is mounted. A recovery device 10 for recovering the ejection failure of the recording head 3 is disposed at a position corresponding to the position).
[0041]
The recovery device 10 includes a capping mechanism 11 for capping the ejection port surface of the recording head 3 and a wiping mechanism 12 for cleaning the ejection port surface of the recording head 3, and interlocks with the capping of the ejection port surface by the capping mechanism 11. Ink recovery such as forcibly discharging ink from the discharge port by suction means (suction pump or the like) in the recovery device, thereby removing ink or bubbles having increased viscosity in the ink flow path of the recording head 3 Process.
[0042]
Further, when the recording head 3 is not in operation or the like, the ejection port surface of the recording head 3 is capped by the capping mechanism 11 to protect the recording head 3 and to prevent ink evaporation and drying. On the other hand, the wiping mechanism 12 is disposed in the vicinity of the capping mechanism 11 and wipes ink droplets adhering to the ejection port surface of the recording head 3.
[0043]
The capping mechanism 11 and the wiping mechanism 12 can keep the ink ejection state of the recording head 3 normal.
[0044]
<Control Configuration of Inkjet Recording Apparatus (FIG. 5)>
FIG. 5 is a block diagram showing a control configuration of the recording apparatus shown in FIG.
[0045]
As shown in FIG. 5, the controller 600 includes an MPU 601, a program corresponding to a control sequence to be described later, a required table, a ROM 602 storing other fixed data, a carriage motor M1, a carriage motor M2, and a recording. A special purpose integrated circuit (ASIC) 603 that generates a control signal for controlling the head 3, and a RAM 604, an MPU 601, an ASIC 603, and a RAM 604, which are provided with image data development areas and program execution areas, are connected to each other. The system bus 605 for transmitting and receiving data, an analog signal from a sensor group to be described below is input, A / D converted, and an A / D converter 606 for supplying a digital signal to the MPU 601 and control of the transport motor M2 It is comprised by the conveyance motor control part 607 etc. which perform.
[0046]
In FIG. 5, reference numeral 610 denotes a computer (or a reader for image reading, a digital camera, or the like) serving as a supply source of image data, and is collectively called a host device. Image data, commands, status signals, and the like are transmitted and received between the host apparatus 610 and the recording apparatus 1 via an interface (I / F) 611.
[0047]
Further, reference numeral 620 denotes a switch group, which instructs activation of a power switch 621, a print switch 622 for instructing printing start, and a process (recovery process) for maintaining the ink ejection performance of the recording head 3 in a good state. For example, a recovery switch 623 for receiving a command input from the operator. Reference numeral 630 denotes a position sensor 631 such as a photocoupler for detecting the home position h, a temperature sensor 632 provided at an appropriate location of the recording apparatus for detecting the environmental temperature, and the like. It is a sensor group. Note that the position sensor 631 also includes an encoder 501 for detecting the rotational position of the transport motor M2.
[0048]
Further, 640 is a carriage motor driver that drives a carriage motor M1 for reciprocating scanning of the carriage 2 in the direction of arrow A, and 642 is a conveyance motor driver that drives a conveyance motor M2 for conveying the recording medium P.
[0049]
FIG. 6 is a diagram for briefly explaining the concept of the rotation control processing of the carry motor according to the present embodiment.
[0050]
The falling edge of the encoder B phase is indicated by (1), the rising edge of the encoder A phase is indicated by (2), the rising edge of the encoder B phase is indicated by (3), and the falling edge of the encoder A phase is indicated by (4).
[0051]
[1] shows a method of acquiring position information in servo control when the stop position corresponds to (1). Only (1) that is the same edge as the stop position is used for control, and (2), (3), and (4) are not used.
[0052]
[2] shows a method of acquiring position information in servo control when the stop position corresponds to (2). Only (2) that is the same edge as the stop position is used for control, and (1), (3), and (4) are not used.
[0053]
[3] shows a method for acquiring position information in servo control when the stop position corresponds to (3). Only (3) that is the same edge as the stop position is used for control, and (1), (2), and (4) are not used.
[0054]
[4] shows a method for acquiring position information in servo control when the stop position corresponds to (4). Only (4) that is the same edge as the stop position is used for control, and (1), (2), and (3) are not used.
[0055]
By performing the processing as described above, the position information in servo control can be avoided from the influence of the position variations (1) to (4) due to variations in component accuracy (for example, variations in photodiode sensitivity).
[0056]
FIG. 7 is a block diagram for explaining the configuration of the transport motor (DC motor) control device of this embodiment.
[0057]
The encoder 501 outputs two signals of A phase and B phase to the encoder signal control unit 502 by driving a motor 515 (corresponding to the conveyance motor M2 in FIG. 5). In the encoder signal control unit 502, an edge detection unit 503 for detecting an edge of the encoder signal is arranged. In the edge detection unit 503, each edge of each phase, that is, the rising edge detection 504 of the A phase, the falling edge detection 505 of the A phase, the rising edge detection 506 of the B phase, and the falling edge detection 507 of the B phase are performed independently. In other words, a signal synchronized with each edge is generated. A signal synchronized with each edge is sent to each edge interval counting section 508, 509, 510, 511, and each edge interval is counted independently. Each edge interval count unit 508, 509, 510, 511 receives an edge detection signal from the edge detection unit 503, and overwrites the velocity information in the velocity / position information storage unit 512 every time the edge interval is determined. The servo controller 513 reads the speed / position information from the speed / position information storage unit 512 in order to obtain speed information necessary for the servo when the servo cycle reaches a predetermined interval. The servo controller 513 performs calculation based on the obtained speed information, position information, and the like, and outputs optimal motor control information to the motor driver 514 (corresponding to the transport motor driver 642 in FIG. 5). The motor driver 514 outputs to the motor 515 according to the input control information, and the motor 515 is driven.
[0058]
FIG. 8 is a schematic diagram for explaining the position control system of the DC motor, and shows a method for applying position servo. In the present embodiment, the position servo is performed as additional value control for an ideal profile described later. The DC motor is controlled by a technique called PID control or classical control, and the procedure will be described below.
[0059]
First, the target position to be given to the control object is given in the form of an ideal position profile 1601. In the present embodiment, for example, this corresponds to the absolute position where the paper conveyed by the line feed motor should reach at the corresponding time. This position information changes with the progress of time. By performing additional value control on the ideal position profile, the apparatus of the present embodiment is driven.
[0060]
The apparatus of the present embodiment includes an encoder sensor 501 and detects physical rotation of the motor. The encoder position information conversion means 1609 is a means for obtaining absolute position information by adding the number of slits detected by the encoder sensor, and the encoder speed information conversion means 1606 is based on the encoder sensor signal and the clock built in the printer. This is means for calculating the current drive speed of the line feed motor.
[0061]
A numerical value obtained by subtracting the actual physical position obtained by the position information conversion unit 1609 from the ideal position profile 1601 is transferred to a position servo feedback process after 1602 as a position error that is insufficient with respect to the target position. Reference numeral 1602 denotes a position servo major loop, and generally means for performing calculation related to the proportional term P is known.
[0062]
As a result of the calculation in the major loop 1602, a speed command value is output. This speed command value is transferred to speed servo feedback processing after 1603. A minor loop of the speed servo is generally performed by a PID operation that performs an operation on the proportional term P, the integral term I, and the differential term D. In the apparatus of this embodiment, in order to improve the followability when a non-linear change in the speed command value occurs and to prevent the adverse effect of the differential operation during the follow-up control, a method generally called a differential leading form is shown. The encoder speed information obtained by the encoder speed information conversion means 1606 is subjected to a differential operation 1607 before taking the difference from the speed command value obtained at 1602. This method itself is not the subject of this embodiment, and depending on the characteristics of the system to be controlled, it may be sufficient to perform this differentiation operation in 1603.
[0063]
In the minor loop of the speed servo, the numerical value obtained by subtracting the encoder speed information from the speed command value is transferred to the PI operation circuit 1603 as a speed error that is insufficient with respect to the target speed, and the energy to be given to the DC motor at that time is Calculation is performed by a method called PI calculation. The motor driver circuit that has received it, for example, uses a means for changing the pulse width of the applied voltage (hereinafter referred to as “PWM (Pulse Width Modulation) control”) while changing the applied voltage duty while the motor applied voltage is constant. Then, the current value is adjusted, the energy applied to the DC motor 515 is adjusted, and the speed control is performed.
[0064]
The DC motor that rotates by being applied with a current value performs physical rotation while being influenced by the disturbance 1608, and the output is detected by the encoder sensor 501.
[0065]
FIG. 9 is a timing chart showing the relationship between each control process.
[0066]
Reference numeral 901 indicates the state of the motor control task, reference numeral 902 indicates the timer interrupt processing state, and reference numeral 903 indicates the position interrupt processing state. The vertical axis 701 of the graph indicates the position, and the horizontal axis indicates the passage of time. Reference numeral 704 denotes an ideal position profile, and reference numeral 705 denotes an actual position profile obtained as a result of actually driving the motor.
[0067]
When the drive control process is activated, drive control preparation is performed at 802. 802 is a process generally described in a motor control task, which selects an ideal position profile table suitable for driving purposes, selects a servo parameter table, sets various work areas, and finally controls timer interrupt processing. Start the timer and exit.
[0068]
When the timer is started at 802, the process shifts to an actual driving step indicated by 803. 803 is a process generally described in the timer interrupt process, for example, interrupts once every 1 msec, reads the encoder value, calculates the current value to be output by PID calculation, etc. On the other hand, this value is output.
[0069]
The ideal position profile 704 changes as the process proceeds with the acceleration control area 711, the constant speed control area 712, and the deceleration control area 713, and the actual position profile 705 is obtained by performing additional value control by arithmetic processing within 803. Will be plotted.
[0070]
In parallel with the operation of 803, whether or not the stop position has been reached is monitored in the system. When the arrival is detected, the arrival detection step 804 to the drive target position is activated and an interrupt is generated. The process proceeds to the drive control end step 805.
[0071]
In 805, the output to the motor is quickly disabled, the timer is stopped, and the control is terminated.
[0072]
By performing the above processes, one drive process reaches the end of the drive control.
[0073]
10 and 11 are flowcharts showing the algorithm of the operation of the apparatus according to this embodiment. FIG. 10 shows the specific contents of the process executed in 802, and FIG. 11 shows the specific contents of the process executed in 803. Is shown.
[0074]
In FIG. 8, when the drive preparation process 802 is started, details of the drive preparation process 1002 are performed. In step 1002, an ideal position profile table suitable for a driving purpose, a servo parameter table, and various work areas are set.
[0075]
In 1003, destination indicates a target position, and is a value itself that the arrival detection step 804 is activated when the encoder reading becomes this value. In 1003, the value of the remainder obtained by dividing this determination by 4 (% 4 in the figure indicates the remainder obtained by dividing by 4) is substituted into modPosition. “Remainder by 4” means whether the stop position is the rising edge of the A phase, the rising edge of the B phase, the falling edge of the A phase, or the falling edge of the B phase This information is used for the calculation processing in 803.
[0076]
In step 1004, the timer that performs the timer interrupt process is activated, and the drive preparation process ends.
[0077]
In FIG. 9, when the processing in the servo timer 803 is started, position information (hereinafter referred to as positionInfo) is acquired in 1102. This means the current position information itself obtained from the encoder. In the present embodiment, it is assumed that the position information is added toward the traveling direction. In addition, all variables appearing in the following description are assumed to be integers.
[0078]
In 1103, the remainder obtained by dividing positionInfo by 4 is assigned to workModPosition. workModPosition is information for identifying whether the current position is the rising edge of the A phase, the rising edge of the B phase, the falling edge of the A phase, or the falling edge of the B phase. It is.
[0079]
In 1104, workModPosition and modPosition are compared, and if workModPosition is equal to or greater than modPosition, the process proceeds to 1105, and otherwise the process proceeds to 1106.
[0080]
When the process proceeds to 1105, the current positionInfo is rounded to a multiple of 4 (replacement) in order to erase the both-phase / both-edge information whose accuracy is not guaranteed, and modPosition which is effective edge information of the stop position is added. The positionInfo that is the current position information is overwritten. Here, when rounded (replaced) to a multiple of 4, the values “93”, “94”, and “95” become “92”, for example. Further, when “97”, “98”, and “99” are rounded, “96” is obtained.
[0081]
Even when the process proceeds to 1106, the current positionInfo is rounded to a multiple of 4 in order to erase both-phase / both-edge information whose accuracy is not guaranteed, and modPosition which is effective edge information of the stop position is added. Since the calculation is rounded up by 4 edges, the positionInfo, which is the current position information, is overwritten after the last 4 subtraction.
[0082]
By calculating 1105 and 1106, it is possible to perform control only with the same edge information as the stop position described in FIG.
[0083]
An example of calculation of 1105 and 1106 will be shown. If the destination value, which is the target position, is “102”, the modPosition value is “2”. Here, for example, even if the value read by the encoder is any of 94 to 97, it is calculated as 94. Moreover, even if it is any value of 98 to 101, it is calculated as 98. As described above, if the target position is 102, any of the values 2, 6, 10, 14,..., 90, 94, 98 is obtained as the calculated position information. It is done. Control is performed using these obtained values.
[0084]
If the target position is “103”, the value of modPosition is “3”. If the same calculation is performed, values of 3, 7, 11, 15,... 91, 95, 99 are obtained as position information. One of the following values is obtained. These values have a difference of an integral multiple of 4 from each other. Therefore, since the edge position value is the same as the stop position, control is performed only with the same edge information.
[0085]
In 1107, PID calculation or the like is performed using the positionInfo calculated in the process so far. Based on the calculation result, current is output to the motor in 1108, and the processing in the servo timer is terminated in 1109.
[0086]
By performing the above processing, the accuracy (resolution) of the stop position is selected by selecting the optimum edge for the stop position from both edges (rising edge, falling edge) of the signals of both phases (A phase and B phase). ), And the control is performed using only the same edge information as the stop position, so that the influence of deterioration (error) of both edge information can be avoided.
[0087]
The above embodiment includes means (for example, an electrothermal converter, a laser beam, etc.) that generates thermal energy as energy used for performing ink discharge, particularly in the ink jet recording system, and the ink is generated by the thermal energy. By using a system that causes a change in the state of recording, it is possible to achieve higher recording density and higher definition.
[0088]
As its typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recorded information and applying a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording head This is effective because film boiling occurs on the heat acting surface of the liquid, and as a result, bubbles in the liquid (ink) corresponding to the drive signal on a one-to-one basis can be formed. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable that the drive signal has a pulse shape, since the bubble growth and contraction is performed immediately and appropriately, and thus it is possible to achieve discharge of a liquid (ink) having particularly excellent responsiveness.
[0089]
As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.
[0090]
Further, although the above embodiment is a serial type recording apparatus that performs recording by scanning the recording head, it is a full line type recording apparatus that uses a recording head having a length corresponding to the width of the recording medium. May be. As a full-line type recording head, either a configuration satisfying the length by a combination of a plurality of recording heads as disclosed in the above-mentioned specification, or a configuration as a single recording head formed integrally. But you can.
[0091]
In addition to the cartridge-type recording head in which the ink tank is integrally provided in the recording head itself described in the above embodiment, it can be electrically connected to the apparatus body by being attached to the apparatus body. A replaceable chip type recording head that can supply ink from the apparatus main body may be used.
[0092]
In addition, it is preferable to add recovery means, preliminary means, and the like for the recording head to the configuration of the recording apparatus described above because the recording operation can be further stabilized. Specific examples thereof include a capping unit for the recording head, a cleaning unit, a pressurizing or sucking unit, an electrothermal converter, a heating element different from this, or a preheating unit using a combination thereof. In addition, it is effective to provide a preliminary ejection mode for performing ejection different from recording in order to perform stable recording.
[0093]
Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrated or may be a combination of a plurality of colors. An apparatus having at least one of full colors can also be provided.
[0094]
In the embodiment described above, the description is made on the assumption that the ink is a liquid, but it may be an ink that is solidified at room temperature or lower, or an ink that is softened or liquefied at room temperature, Alternatively, the ink jet method generally controls the temperature of the ink so that the viscosity of the ink is within a stable discharge range by adjusting the temperature within a range of 30 ° C. or higher and 70 ° C. or lower. It is sufficient if the ink sometimes forms a liquid.
[0095]
In addition, as a form of the recording apparatus according to the present invention, a copying apparatus combined with a reader or the like, and a transmission / reception function are provided as an image output terminal of an information processing apparatus such as a computer or the like. It may take the form of a facsimile machine.
[0096]
[Other Embodiments]
In addition, an object of each embodiment is to supply a storage medium (or recording medium) on which a program code of software that realizes the functions of the above-described embodiments is recorded to a system or apparatus, and a computer (or CPU) of the system or apparatus Needless to say, this can also be achieved by reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.
[0097]
Furthermore, after the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the function is determined based on the instruction of the program code. It goes without saying that the CPU or the like provided in the expansion card or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.
[0098]
When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the flowcharts described above.
[0099]
【The invention's effect】
As described above, according to the present invention, it is possible to stably obtain a certain control performance without being affected by variations in component performance, and to realize a stable quality as an industrial product to be mass-produced. It becomes possible.
[Brief description of the drawings]
FIG. 1 is a model diagram of an encoder.
FIG. 2 is a diagram showing an ideal differential output signal waveform;
FIG. 3 is a diagram showing a differential output signal waveform when there is a difference in photodiode sensitivity.
FIG. 4 is an external perspective view showing an outline of the configuration of an ink jet recording apparatus that is a representative embodiment of the present invention.
5 is a block diagram showing a configuration of a control circuit of the ink jet recording apparatus shown in FIG. 1. FIG.
FIG. 6 is a diagram briefly explaining the concept of processing according to an embodiment of the present invention.
FIG. 7 is a block diagram for explaining a configuration of an apparatus according to an embodiment of the present invention.
FIG. 8 is a diagram for explaining a position control system of a DC motor.
FIG. 9 is a timing chart showing the relationship between each control process.
FIG. 10 is a flowchart showing an algorithm showing an operation of the apparatus according to the embodiment of the present invention.
FIG. 11 is a flowchart showing an algorithm showing the operation of the apparatus according to the embodiment of the present invention.
[Explanation of symbols]
101 LED
102 Code wheel
103 detector
104 Light transmitting part
105 Parts that do not transmit light
106-109 photodiode
110-113 Electrical signal
114-115 comparator
116-117 output

Claims (4)

A motor control device for controlling rotation of a motor,
First frequency signal generating means for generating a first pulse signal having a predetermined frequency corresponding to the driving speed of the motor;
Second frequency signal generating means for generating a second pulse signal that is about 90 degrees out of phase with the first pulse signal at the predetermined frequency;
Detection means capable of independently detecting four types of edges, a rising edge and a falling edge of the first pulse signal and a rising edge and a falling edge of the second pulse signal;
Control means for controlling the rotational position of the motor based on the detection result of the detection means, using only the same kind of edge as the edge corresponding to the stop target position of the motor among the four kinds of edges, Control means for performing rotational position control of the motor until the motor is stopped at the stop target position;
A motor control device comprising: A motor, first frequency signal generating means for generating a first pulse signal having a predetermined frequency in accordance with the driving speed of the motor, and the first pulse signal having the predetermined frequency have a phase of about 90 degrees; Four types of second frequency signal generating means for generating a shifted second pulse signal, rising edge and falling edge of the first pulse signal, and rising edge and falling edge of the second pulse signal A control method of a motor device for controlling a motor device comprising detection means capable of independently detecting edges of
In performing the rotational position control of the motor based on the detection result of the detection means, the motor is controlled by using only the edge of the same type as the edge corresponding to the stop target position of the motor among the four types of edges. A method for controlling a motor device, comprising: performing rotational position control of the motor until stopping at a stop target position. A program for causing a computer to execute the motor device control method according to claim 2. A storage medium storing the program according to claim 3 in a computer-readable manner.

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