JP2002272161A - Apparatus and method for movement control - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce unevenness in control and speed in a constant speed region while performing steep acceleration / deceleration. In a recording apparatus that controls movement of a carriage using a brushless DC motor (1314), an angular position of a motor is detected by an angle detector (1315), and a commutation timing generation block (1323) generates a commutation timing based on the detected angular position. A commutation timing signal is generated, and the second commutation timing generation block 206 generates a commutation timing signal based on the reference clock. The commutation timing selection block 207 switches a signal to be output to the phase current drive block 1311 between the acceleration / deceleration region and the constant velocity region according to the state of the commutation timing switching signal 204.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for movement control, and more particularly to an apparatus and a method for controlling movement of a driven body using a brushless DC motor.

[0002]

2. Description of the Related Art As information output devices in word processors, personal computers, facsimile machines, etc., printers for recording desired information such as characters and images on sheet-like recording media such as paper and film are widely used. I have.

[0003] Various types of printing methods are known for printers. However, ink-jet printing is possible because non-contact printing is possible on printing media such as paper, colorization is easy, and quietness is high. In recent years, the method has attracted special attention, and its configuration is to mount a printhead that ejects ink according to desired print information and print while performing reciprocating scanning in a direction that intersects the feed direction of a print medium such as paper. Are generally widely used because they are inexpensive and easy to miniaturize.

In general, an ink jet printer includes a carriage on which a recording head as recording means and an ink tank are mounted, a conveying means for conveying a recording medium, and a control means for controlling these. Motors are used as power sources for the carriage and the transport means, and these motors are also required to have high performance.

For driving the carriage of the printer, for example, a stepping motor, a DC motor, a brushless DC
A motor or the like is used. In general, a stepping motor is used in a low-priced printer, and a DC motor or a brushless DC motor is used in a printer of an intermediate level or higher which requires higher performance.

[0006] The type of motor used is also determined by the characteristics of the motor. For example, a DC motor has a problem in the durability of a brush. Therefore, when the durability is important, a brushless DC motor is often used.

[0007] As a method of controlling these motors, it is common to control the position and speed in a closed loop using a two-phase linear encoder and a position servo circuit (first method).

As a second method, Japanese Patent Laid-Open No. 10-2
As proposed in Japanese Patent Application Laid-Open No. 15597, a method in which a three-phase synchronous motor is operated as a stepping motor in a low-speed region to accurately perform positioning control, and performs a sensorless operation in a high-speed region, focusing on the rotation speed of a rotor. Is also known.

[0009]

However, the above-described conventional control of the CR motor has the following problems.

In the first method of performing control in a closed loop, steep acceleration and deceleration can be efficiently performed at the rise and fall of acceleration and deceleration by making use of the characteristics of a brushless motor. In the recording area where the drive of the drive is required, the average speed in the entire area is almost the same as the target speed in order to detect the speed error and control the speed command value. The value often differs slightly from the speed (control fluctuation). In a printing apparatus such as a printer, unevenness also occurs in a printed image due to the fluctuation of the control and the speed.

In the second method, the accuracy can be improved by operating as a stepping motor in an acceleration / deceleration region including at the time of starting and stopping.
Since a margin for preventing step-out is required, the characteristics of the brushless motor cannot be fully utilized, and steep acceleration / deceleration cannot be performed efficiently. In a recording area where driving at a constant speed is required, control and speed fluctuations occur in order to detect a speed error and control a speed command value, as in the first method. Therefore, if the printing apparatus is controlled by this method, unevenness occurs in the printed image.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is intended to provide steep acceleration / deceleration, control in a constant speed region, and movement control capable of reducing speed unevenness. It is an object to provide an apparatus and a method.

[0013]

One embodiment of the present invention for solving the above-mentioned object is a movement control device for controlling the movement of a driven body using a brushless DC motor, which is attached to the motor. An angle detecting means for detecting an angular position of the motor; a first driving means for generating a first driving signal based on a signal from the angle detecting means; and a reference signal having a predetermined frequency. A second driving means for generating a second driving signal, and in a region where the driven body accelerates / decelerates, the motor is driven by the first driving signal, and the driven body moves at a constant speed. In a region, the movement control device includes: a drive control unit that drives the motor by the second drive signal.

That is, in the present invention, when the movement of the driven body is controlled using the brushless DC motor, the angular position of the motor is detected, and the first drive signal is generated based on the detected angular position. And generating a second drive signal based on a reference signal of a predetermined frequency, and driving the motor by the first drive signal in a region where the driven body accelerates / decelerates, so that the driven body has a constant speed. The motor is driven by the second drive signal in the region where the movement is performed.

In this manner, in a region where acceleration / deceleration is performed, sharp acceleration / deceleration is performed in a short time by making use of the characteristics of the brushless DC motor. Thus, the change in the rotation speed of the motor can be reduced.

When this movement control device is used for controlling the carriage of a printing apparatus, the movement speed of the carriage in the printing area is stabilized, so that unevenness during printing is reduced and steep acceleration / deceleration is possible. Therefore, the width of the recording apparatus in the scanning direction can be reduced, and the entire apparatus can be made compact.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference Example First, a general example in which a DC motor is used to control a printer will be described with reference to FIGS.

FIG. 9 is a diagram showing a schematic configuration of a general printer. In FIG. 9, reference numeral 1101 denotes a control unit which controls the entire printer. The control unit 1101 is a CPU 1
101A, a ROM 1101B, and a RAM 1101C. The CPU 1101A executes various control programs stored in the ROM 1101B to control the printer. The RAM 1101C is a CPU 1101
A has a storage area for temporarily storing data and the like in order for A to execute various processes. Reference numeral 1102 denotes a bus, which connects the control unit 1101 to peripheral units via a bus.

Reference numeral 1103 denotes an image buffer.
A buffer for temporarily storing part or all of the image data received via the / F unit. 1104 is an external I /
F unit, under the control of the control unit 1101,
A command is transmitted / received to / from the host 1106 via the host computer 105 and image data is received. A connection unit 1105 connects the printer and the host 1106.

Reference numeral 1106 denotes a host;
The printer 5 is connected to a printer, and transmits and receives commands to and from the printer and transmits image data.

Reference numeral 1107 denotes a motor control unit which controls driving of the carriage motor 1111. Reference numeral 1111 denotes a carriage motor (CR motor).
Is reciprocated in the main scanning direction.

Reference numeral 1112 denotes a printhead control unit which processes image data sent from the host in a form suitable for the printhead, and transfers image data to the printhead in synchronization with reciprocation of the printhead in the main scanning direction. Printing is performed by applying various control signals and ejection pulses.

Reference numeral 1113 denotes a carriage (CR) on which a print head is mounted. The image data transferred from the print head control unit 1112 is singly or plurally printed in the sub-scanning direction. 111
The recording is performed on the recording paper 1206 by applying the discharge pulse sent from 2 and discharging ink droplets, and this recording operation is repeated while reciprocating in the main scanning direction.

Reference numeral 1114 denotes a CR motor drive signal, which is output from the motor control unit 1107 and outputs a CR motor 111
1 is driven. A paper transport (LF) motor 1115 is driven by a control unit (not shown) to transport a recording paper.

Reference numeral 1116 denotes a linear encoder scale. In this embodiment, it is assumed that 1200 lines pairs / inch vertical stripes are recorded in the main scanning direction. 11
A linear encoder sensor 17 reads the position information of the linear encoder scale 1116CR1113 and outputs a binary signal. Reference numeral 1118 denotes a position information processing unit which detects a recording position, calculates a speed as a change in position, and calculates an acceleration as a change in speed.

Reference numeral 1206 denotes a recording sheet, under the control of the recording head control unit 1112, an image is formed by a plurality of ink droplets discharged from the recording head mounted on the CR 1113.

The recording operation of the printer having the above-described configuration will be described in order. Under the control of the control unit 1101, the image data sent from the host 1106 via the connection unit 1105 and the external I / F unit 1104 is controlled. One or all copies are received and stored in the image buffer 1103.

When the image data is stored in a recordable amount, the CR 111 is controlled based on the control of the motor control unit 1107.
3 is started, and after accelerating to a recordable speed, the operation shifts to the constant velocity region. When the CR 1113 is stabilized in the recordable constant velocity area and reaches the recording start position, the image buffer 1
The image data stored in 103 is sent to the head control unit 1112 via the bus 1102, and is transferred to the recording head mounted on the CR 1113.

Then, the CR 111 on which the recording head is mounted
The position 3 is controlled based on a value obtained by reading the position information of the linear encoder scale 1116 by the linear encoder sensor 1117, and the print head is controlled by the CR motor 1111 while being moved at a constant speed in the main scanning direction. An image is formed on the recording paper 1206 by applying an ink ejection signal sent from the unit 1112. When the recording of the image data in one scan is completed, the deceleration control is performed until the CR 1113 stops, and the image is stopped at the target position.

Each time printing in the main scanning direction is completed,
(LF) The recording paper 1206 is conveyed by the motor 1115. By repeating the above operation, recording of one page is completed.

FIG. 10A is a graph showing the operating characteristics of the CR 1113 in relation to speed and time. In the figure,
Reference numeral 1201 denotes an acceleration region of the CR 1113;
3 is the time from when the recording speed reaches the recordable speed until the recording area 1202 is entered. Reference numeral 1202 denotes a recording area.
It is controlled based on the position information from the linear encoder scale 1116. Reference numeral 1203 denotes a deceleration region of the CR 1113, which is a time until the CR 1113 decelerates and stops.

When the deceleration area ends, when performing bidirectional recording, the CR 1113 moves to the opposite direction to enable recording.

The printer according to the present embodiment has two recording modes, a high-speed recording mode and a high-resolution recording mode, as recording modes. Reference numeral 1204 denotes a relationship between the CR speed and time in the high-speed recording mode.
This shows the characteristics when recording is performed at a resolution of 600 dpi in the main scanning direction.

Reference numeral 1205 denotes a relationship between the CR speed and the time in the high-resolution recording mode.
This shows the characteristics when recording is performed at a resolution of 900 dpi in the main scanning direction.

Here, assuming that the ejection frequency of the recording head is constant, the resolution of 900 dpi is 600 dpi.
Therefore, the recording speed at 900 dpi is ／ times the recording speed at 600 dpi.
Similarly, the recording speed at 1200 dpi is 600 dpi.
Recording speed, which is half the recording speed of

As is apparent from the change in the speed in the printing area of FIG. 10A, in the printing area where the driving at the constant speed is required, in order to detect the error from the target speed and control the speed command value, The speed at each time point has a slightly different value from the target speed, and the speed fluctuates like a swell on the graph.

FIG. 10B shows a timing signal output to the motor control unit 1107 via the bus 1102 under the control of the control unit 1101, in relation to the driving state of the CR motor.

In the figure, reference numeral 1211 denotes an ENB signal, which makes the motor control unit 1107 operable. 12
Reference numeral 12 denotes a DIR signal which controls the rotation direction of the CR motor. In the present description, normal rotation is instructed when the logic state of the signal is LOW, and reverse rotation is instructed when the signal is HIGH.
Reference numeral 1213 denotes a BRK signal, which brakes the CR motor in the latter half of the deceleration region 1203. 1214 is PW
M control signal, and a PWM signal 1 based on the result calculated based on the position information from the linear encoder sensor 1117.
The duty of 215 is controlled, and the speed of CR is controlled.
Reference numeral 1215 denotes a PWM signal, which is a PWM control signal 1214.
Controls the duty.

When driving the CR motor, the control unit 11
01, the BRK signal is released via the bus 1102, the DIR signal 1212 is set in the normal rotation direction, the duty of the PWM signal 1215 is set by the PWM control signal 1214, and the motor control unit 1107 is initialized. From, EN
The B signal is output as 1211 to make the motor control unit 1107 operable.

Next, a PWM control signal 1214 is output from the result calculated based on the position information from the linear encoder sensor 1117 to control the duty of the PWM signal 1215, and the CR motor is driven to drive the CR 1113. . Here, the characteristic required in the acceleration / deceleration region is not positioning accuracy, but smooth and rapid acceleration / deceleration. This is the acceleration region 1201 of CR1113.
By reducing the time required for the deceleration area 1203, the total recording time can be reduced, and
This is because the width of the apparatus in the scanning direction can be reduced. Therefore, in the acceleration area 1201, the recording area 120
It is required that the speed becomes uniform in a short time before entering into 2.

Reference numeral 1202 denotes a recording area, which is controlled based on position information from the linear encoder sensor 1117. Reference numeral 1203 denotes a deceleration region of the CR 1113, which indicates a time required for the CR 1113 to decelerate and stop. When the deceleration area ends, the CR 1113 is ready for recording in the opposite direction.

For a specific speed control method,
The details are described in JP-A-5-80856, JP-A-6-91977, and the like, and a description thereof will not be repeated.

FIG. 11A is a graph showing a C value when a DC motor is used.
FIG. 11B is a block diagram of an R motor control unit 1107, and FIG.
FIG. 4 is a block diagram of a CR motor control unit 1107 when a brushless DC motor is used.

In both figures, reference numerals 1211 to 1215 are the same as those described above with reference to FIG.
Reference numeral 1301 denotes a PWM generation block that generates a PWM signal 1215 whose duty is controlled based on the PWM control signal 1214. Reference numeral 1311 denotes a DC motor phase current drive block which generates a DC motor drive signal based on the signals 1211-1215 and drives the DC motor 1312.

Reference numeral 1313 denotes a three-phase current drive block of the brushless DC motor, which switches the signals 1211 to 1215 and the order of energization of the U-phase, V-phase, and W-phase drive coils (hereinafter referred to as commutation). A drive signal for the brushless DC motor is generated according to the control of the timing generation block 1323, and the brushless DC motor 1314 is driven.

Reference numeral 1315 denotes an angle detection unit of a rotor for driving each phase. In this embodiment, a Hall element is used.
A sine wave is generated at a position approximately 60 degrees in the center between the phases arranged at 120 degrees in electrical angle. The sine wave has a positive potential when the N pole of the rotor approaches and a negative potential when the N pole approaches. Shall be.

Reference numeral 1316 denotes a U-phase position signal, 1317 denotes a V-phase position signal, and 1318 denotes a W-phase position signal. Reference numeral 1319 denotes a waveform shaping block which includes these three phases 1316-1 to 1316-1.
The position signal at 318 is binarized. Reference numeral 1320 denotes a U-phase binarization position signal, 1321 denotes a V-phase binarization position signal, and 1322 denotes a W-phase binarization position signal.

A reference numeral 1323 denotes a commutation timing generation block, which determines a brushless DC motor 131 based on the relationship between the binarized rotor position signal from the waveform shaping block 1319 and the DIR signal 1212 according to the truth table of FIG.
4, U, V, W, and commutation timing for driving each phase are generated.

Reference numerals 1331 to 1340 denote switching elements for interrupting the current flowing through the motor. 13 of these
Reference numerals 35 to 1340 denote switching elements for interrupting the current flowing in the brushless DC motor. The switching elements 35 to 1340 generate the U, V, and W of the brushless DC motor 1314 and the commutation timing for driving each phase generated by the commutation timing generation block 1323. , And is controlled in consideration of the enable condition and the PWM modulation.

The DC motor has I / Os of 1211-1214.
Since control can be made equivalent to that of the brushless DC motor via F, only control of the brushless DC motor will be described below.

Each of FIGS. 12A to 14C shows a waveform at the corresponding reference numeral in FIG. 11B.

FIG. 12A shows a signal waveform detected by the rotor angle detector 1315. 3 phase 1 position signal 3
Assuming that one cycle from 16 to 1318 is 360 ° and a point where the rising slope of the U-phase position signal 1316 reaches substantially the center of the amplitude is 0 ° in electrical angle, the V-phase position signal 131
7 is a timing delayed by 120 °, and the W-phase position signal 1318 is detected at a timing delayed by 240 °.

FIG. 12B shows the position signals 1316 to 1318.
And a binarized signal obtained by using a substantially central potential as a threshold value.

FIG. 12C shows switching elements 1335 to 1340 for interrupting the current flowing through the brushless DC motor.
5 is a waveform of the driving signal of FIG. In FIG. 12C, 1401
Is a drive signal for the U-phase power supply side switching element 1335, and controls the connection state between the U-phase excitation coil and the power supply.
Reference numeral 1402 denotes a drive signal for the U-phase GND side switching element 1336, which connects the U-phase excitation coil to GND,
The connection to GND is interrupted based on the WM signal.

Similarly, reference numeral 1403 denotes a drive signal for the V-phase power supply side switching element 1337, and reference numeral 1404 denotes a drive signal for the V-phase GND side switching element 1338.
1405 is a W-phase power supply side switching element 133.
Reference numeral 9406 denotes a drive signal, and reference numeral 1406 denotes a drive signal of the W-phase GND-side switching element 1340. These signals 1
Reference numerals 401 to 1406 denote HIGH for ON and LOW for OFF.

As described above, when the DIR 1212 is LOW, the rotation direction indicates the normal rotation direction.

In FIG. 12C, when the rotation angle of the rotor reaches an electrical angle of 0 °, the U, V, and W phase binary position signals 1
320 to 1322 are H, L, and H, respectively.
In accordance with the truth table of FIG.
401 to 1406 output L, H, L, L, H, L, respectively, the W phase is connected to the power supply, the U phase is connected to GND, and the current flows from the W phase to the U phase, Gives a turning force to the trochanter.

When the rotation angle of the rotor reaches the electrical angle of 60 °, the U, V, and W phase binarized position signals 1320 to 1322 are output.
Are H, L, and L, respectively, and drive signals 1401 to 1406 of the respective switching elements according to the truth table of FIG.
Output L, H, H, L, L, L respectively, the V phase is connected to the power supply, the U phase is connected to GND, the current flows from the W phase to the U phase, Give rotational force. Less than,
Similarly, the rotor continues to rotate from 120 ° to 360 (0) °.

FIG. 13 shows a commutation timing generation block 1
323 is a truth table, and is a U-phase binarized position signal (HS_
U) 1320, W-phase binary position signal (HS_V) 132
1. W-phase binarized position signal (HS_W) 1322, DI
The output state of the drive signals 1401 to 1406 of each switching element with respect to the input signal of R1212 is shown.

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition,
In the embodiment described below, a printer will be described as an example of a recording apparatus using an inkjet recording method.

In this specification, “recording” (sometimes referred to as “print”) means not only the formation of significant information such as characters and figures, but also whether a person is visually perceived as significant or insignificant. Regardless of whether or not the image has been exposed so as to be able to perform the process, the case where an image, a pattern, a pattern, or the like is widely formed on a recording medium or a case where the medium is processed is also described.

The “recording medium” is not limited to paper used in a general recording apparatus, but is widely applicable to ink, such as cloth, plastic film, metal plate, glass, ceramics, wood, and leather. Things are also represented.

Further, “ink” (sometimes referred to as “liquid”) is to be interpreted widely as in the definition of “recording (printing)”, and by being applied on a recording medium, A liquid that can be used for forming an image, a pattern, a pattern, or the like, processing a recording medium, or processing ink (for example, coagulating or insolubilizing a colorant in ink applied to the recording medium) is used.

In the following description, the same parts as those in the above-mentioned reference example are denoted by the same reference numerals, and the description will be omitted.

FIG. 1 is a view showing a schematic configuration of a printer according to an embodiment of the present invention.
Reference numerals 1106 and 1111 to 1206 are the same as in the above-described reference example.

Reference numeral 101 denotes a block for driving a brushless three-phase DC motor.
02, the CR motor is driven, and the recording area 120
In the second, based on the drive signal generated from the oscillator,
Control is performed to drive the CR motor. Also, 102
Is a rotor position signal.

The operation of the printer according to this embodiment will be described. Under the control of the control unit 1101, the host 110 is connected via the connection unit 1105 and the external I / F unit 1104.
6 is received and stored in the image buffer 1103.

When the received image data reaches a recordable amount, the CR 1113 is controlled by the motor control unit 101.
And accelerates to a recordable speed, and thereafter shifts to a constant velocity region. CR1113 is stable in the recordable constant velocity area,
When the image data reaches the recording start position, the image data stored in the image buffer 1103 is sent to the head control unit 1112 via the bus 1102, and is transferred to the recording head mounted on the CR 1113.

The CR 1113 on which the recording head is mounted is controlled based on the position information of the linear encoder scale 1116 read by the linear encoder sensor 1117, and is moved at a constant speed in the main scanning direction by driving the CR motor 1111. Meanwhile, an image is formed on the recording paper 1206 by applying an ink ejection signal sent from the recording head control unit 1112 to the recording head. When the recording of the image data in this scanning is completed, the CR1113
Is decelerated until it stops, and stopped at the target position. When both-side recording is performed, preparation is made for recording in the reverse direction.

The recording paper 1206 is transported by a recording paper transport motor (not shown) for each recording in the main scanning direction. By repeating such an operation, recording of one page is performed.

Next, the block 101 for driving a brushless three-phase DC motor according to this embodiment will be described in detail with reference to the drawings.

FIG. 2 shows a brushless 3 according to this embodiment.
FIG. 3 is a diagram showing a detailed configuration of a phase DC motor driving block 101, in which FIG.
Reference numerals 311 to 1323 are the same as those in the above-described reference example.

Reference numeral 203 denotes a commutation switching control block.
Based on the change in the speed of the position signal of the rotor binarized by the waveform shaping block 1319 in the above reference example,
A switching signal 204 for switching between the drive timing from the second commutation timing generation block 206 and the drive timing from the commutation timing generation block 1323 is output. This commutation timing switching signal 204 is output HIGH when the CR motor rotates at substantially constant speed.

Reference numeral 205 denotes a PWM generation block, which is similar to the PWM generation block 1301 of the above-described reference example.
Based on the WM control signal 1214, a PWM signal 1215 whose duty is controlled is generated. Also, the duty of the PWM control signal 1214 is stored at the rising point of the commutation timing switching signal 204, and the PWM signal is output at the stored constant duty while the commutation timing switching signal 204 is HIGH.

Reference numeral 206 denotes a second commutation timing generation block which determines a commutation timing for driving at a desired speed.
For example, it is generated with the accuracy of a quartz oscillator.

Reference numeral 207 denotes a commutation timing selection block, which receives a drive timing from the second commutation timing generation block 206 and a commutation timing generation block 1323 according to a signal from the commutation timing switching signal 204.
From the drive timing. When the commutation timing switching signal 204 is HIGH, the drive timing output from the second commutation timing generation block 206 is selected.

FIG. 3A is a graph showing the relationship between the speed and time when the CR moves in this embodiment, and FIG. 3B is a graph showing the relationship between acceleration and time when the CR moves in this embodiment. FIG. 3C is a diagram showing a state of an I / F signal and a PWM signal between the three-phase brushless DC motor driving block 101 and the control unit 1101 in this embodiment. All three figures are described for the same movement.

In FIG. 3A, reference numerals 1201 to 1203 denote:
The same parts as in the above reference example are shown, and 301 to 30 are shown.
Reference numeral 2 also indicates the relationship between speed and time when moving in a different recording mode, similarly to the above-described reference examples 1204 to 1205. Comparing FIG. 3A and FIG. 10A, the present embodiment shown in FIG. 3A has reduced speed unevenness (fluctuation) in a recording area moving at a constant speed.

In FIG. 3B, reference numeral 303 denotes a temporal change of the acceleration when the CR moves. As shown, the acceleration has a value of + (plus) in the acceleration region 1201;
In the recording area 1202, the value is substantially 0, and in the deceleration area, the value is-(minus).

In FIG. 3C, 1121 to 1124 are:
A signal similar to that of the above-described reference example is shown. Reference numeral 304 indicates that the duty of the PWM signal 1215 in the recording area is constant in the present embodiment.

FIG. 4 shows in detail the state of each signal when the control in the three-phase brushless DC motor driving block 101 in the present embodiment shifts from control on the acceleration area 1201 to control on the recording area 1202. It is a timing chart.

In this figure, 401 indicates a change in the state of the U-phase binarization position signal 1320, 402 indicates a change in the state of the V-phase binarization position signal 1321, and 403 indicates a state of the W-phase binarization position signal 1322. Changes are shown respectively. The point indicated by the dotted line in the figure is the timing of transition from the acceleration state to the constant velocity state.

Reference numeral 404 denotes the value of the period counter of the binarized position signal. In this case, corresponding to the rising and falling edges of any of the three-phase binarized position signals 401 to 403, While resetting the counter,
Count the reference clock.

Reference numeral 405 indicates the state of the latch, and the count value of the counter is held corresponding to each edge, as in the case of 404. 406 is a latch timing,
The timing at which the count value 404 of the counter is stored in the latch 405 is shown.

Reference numeral 407 denotes a comparison timing, which indicates a timing at which the count value 404 of the counter is compared with the value of the latch 405. Reference numeral 408 denotes a switching timing, which indicates the timing at which the count value 404 of the counter is compared with the value of the latch 405 and the two are determined to be substantially equal (the difference is within a certain range).

Reference numeral 409 denotes a selection signal, which becomes HIGH in accordance with 408 when it is determined that the comparison results are substantially equal.

Reference numeral 410 denotes a U-phase power supply side generator signal indicating commutation timing to a U-phase power supply, and 411 denotes a U-phase G signal.
U-phase GND-side generator signal indicating commutation timing to ND, 412 is a U-phase power supply side generator signal indicating commutation timing to V-phase power supply, 413 is V-phase GN
V-phase GND side generator signal indicating commutation timing to D, 414 is a W-phase power supply side generator signal indicating commutation timing to a W-phase power supply, 415 is W-phase GND
7 is a W-phase GND-side generator signal indicating a commutation timing to the W-phase. These six signals are generated by the second commutation timing generation block 206.

Reference numeral 416 denotes a PWM signal, which indicates a state when the PWM signal 1215 in the above-described reference example has shifted from an acceleration state to a constant velocity state.

As shown in FIGS. 1 to 4, in the present embodiment, I / F signals 1211 to 121 from control unit 1101 are provided.
4, the brushless DC motor 131
4 starts rotation, and the CR accelerates to a designated target speed according to the CR speed curve 301 or 302 and the acceleration curve 303 according to the control of the PWM control signal 1214.
At this time, the duty of the PWM signal 304 decreases as it accelerates.

When the CR approaches the target speed, the acceleration decreases and the speed becomes substantially equal to the target speed. FIG. 4 shows a case where CR becomes substantially equal to the target speed at the time indicated by the dotted line.

The main parts of the hardware design according to the present embodiment will be described below with reference to a description example of VHDL and a state transition diagram.

First, the assignment to each variable used in the following is described in VHDL: width <= "0000000000000001"; print_position <= "0000000000010000"; down_position <= "0000000100000000"; end_position <= "0000000100010000"; const_zero < = "0000000000000000"; sel <= tmp_sel; tmp_edge_hl_u <= f_sens_u and (not tmp_sens_u); tmp_edge_hl_v <= f_sens_v and (not tmp_sens_v); tmp_edge_lh_v <= (not tmp_sens_v) and tmp_sens_v; tmp_edge_lh_w <= (not tmp_sens_w) and tmp_sens_w; edge_all <= tmp_edge_hl_u or tmp_edge_hl_h_edge or edge_tmp_edge

FIG. 5A is a state transition diagram of the commutation switching control block 203. As shown in the figure, the commutation switching control block 203 includes a standby state (wait_start), an acceleration state (ramp_up_s), a recording state for performing constant-speed movement (print_s),
It takes four states: deceleration state (ramp_down_s). FIG. 5B
Are the waiting state (wait_2) and the binarized position signals 1320 to 13
FIG. 21 is a state transition diagram of a process (ph_count) for counting the width (count) between 22 change points and switching the state of an ENB signal (enb).

The processing performed in wait_2 in FIG.
L_count <= const_zero; count <= "0000000000000000"; position <= "0000000000000000"; f_sens_u <= tmp_sens_u; f_sens_v <= tmp_sens_v; f_sens_w <= tmp_sens_w; tmp_sens_u; = sens_w; tmp_sel <= '0'; edge_hl_u <= '0'; edge_hl_v <= '0'; edge_hl_w <= '0'; edge_lh_u <= '0'; edge_lh_v <= '0'; edge_lh_w <= '0 ';

If the process T20 performed in the state of ph_count in FIG. 5B is described in VHDL, if (edge_all = '1') then position <= position + 1; l_count <= count; count <= "0000000000000000"; edge_hl_u <= tmp_edge_hl_u; edge_hl_v <= tmp_edge_hl_v; edge_hl_w <= tmp_edge_hl_w; edge_lh_u <= tmp_edge_lh_u; edge_lh_v <= tmp_edge_lh_v; (edge_lh_w; = count)) then tmp_sel <= '1'; else tmp_sel <= '0'; end if; else count <= count + 1; end if; f_sens_u <= tmp_sens_u; f_sens_v <= tmp_sens_v; <= Sens_u; tmp_sens_v <= sens_v; tmp_sens_w <= sens_w;

As shown in FIG. 5A, the transition from the standby state to the acceleration state is performed when the ENB signal becomes HIGH.
(enb = '1'), the transition from the acceleration state to the recording state is performed when the constant velocity detection signal becomes HIGH (tmp_sel = '
1 ') or when the position of CR enters the recording area. The constant speed detection signal (tmp_sel) is set to HIGH in the state of ph_count shown in FIG. 5B.
The width between the changing points of the binarized position signals 1320 to 1322 (cou
nt) is equal to the width (1_count) one cycle before within the fluctuation width (width).

The transition from the recording state to the deceleration state is as follows.
This is performed when the constant speed detection signal becomes LOW (tmp_sel = '0') or when the position of the CR enters the deceleration region.
This is performed when the ENB signal becomes LOW (enb = '0') or when the CR moves to the stop position.

FIGS. 6A and 6B are state transition diagrams of the second commutation timing generation block 206. FIG. As shown, the count is reset in the second waiting state (wait_2), and the commutation switching control block 203 resets the constant speed detection signal (s
When el = 1) is set, it moves to the ph_count2 state,
The count for the commutation cycle (count_value + 1) of the target speed is performed (T15).

When the processing at T15 is described in VHDL, Becomes

In the first waiting state (wait_1), the variables (g1_h; g1_l; g2_h; g2_l; g3_h; g3) corresponding to the six drive signals
_l) is cleared, and when the constant speed detection signal (sel = 1) is set in the commutation switching control block 203, the flow shifts to a ph_gen state which is a subroutine.

If the processing in the wait state (wait_1) is described in VHDL, g1_h <= '0'; g1_l <= '0'; g2_h <= '0'; g2_l <= '0'; g3_h <= '0 g3_l <= '0';

FIG. 7 is a state transition diagram of the subroutine ph_gen of FIG. 6B. As shown in the figure, the state shifts to one state (ph_state1 to 6) corresponding to one of the six excitation states detected at the timing (sel = 1) when the state shifts to the constant velocity region. Then, the rotation direction and commutation period of the DIR signal 1212
The transition between the six states (ph_state1 to 6) is performed for each (count_value + 1), and the drive signal (g1_h;
g1_l; g2_h; g2_l; g3_h; g3_l).

When the drive signal set in each of T22 to T33 is described by VHDL, T22 g1_h <= '1'; g1_l <= '0'; g2_h <= '0'; g2_l <= '1'; g3_h <
= '0'; g3_l <= '0'; T23 g1_h <= '1'; g1_l <= '0'; g2_h <= '0'; g2_l <= '0'; g3_h <
= '0'; g3_l <= '1'; T24 g1_h <= '0'; g1_l <= '0'; g2_h <= '1'; g2_l <= '1'; g3_h <
= '0'; g3_l <= '0'; T25 g1_h <= '0'; g1_l <= '1'; g2_h <= '1'; g2_l <= '0'; g3_h <
= '0'; g3_l <= '0'; T26 g1_h <= '0'; g1_l <= '1'; g2_h <= '0'; g2_l <= '0'; g3_h <
= '1'; g3_l <= '0'; T27 g1_h <= '0'; g1_l <= '0'; g2_h <= '0'; g2_l <= '1'; g3_h <
= '1'; g3_l <= '0'; T28 g1_h <= '0'; g1_l <= '1'; g2_h <= '0'; g2_l <= '0'; g3_h <
= '1'; g3_l <= '0'; T29 g1_h <= '0'; g1_l <= '1'; g2_h <= '0'; g2_l <= '1'; g3_h <
= '0'; g3_l <= '0'; T30 g1_h <= '0'; g1_l <= '0'; g2_h <= '1'; g2_l <= '0'; g3_h <
= '0'; g3_l <= '1'; T31 g1_h <= '1'; g1_l <= '0'; g2_h <= '0'; g2_l <= '0'; g3_h <
= '0'; g3_l <= '0'; T32 g1_h <= '1'; g1_l <= '0'; g2_h <= '0'; g2_l <= '1'; g3_h <
= '0'; g3_l <= '0'; T33 g1_h <= '0'; g1_l <= '0'; g2_h <= '0'; g2_l <= '1'; g3_h <
= '1'; g3_l <= '0';

For example, in the state of ph_state2, when DIR signal 1212 = 0 and (count = count_value), T
22 settings, g1_h <= '1'; g1_l <= '0'; g2_h <= '0'; g2_l <= '1'; g3_h <
= '0'; g3_l <= '0'; From the setting of T23, g1_h <= '1'; g1_l <= '0'; g2_h <= '0'; g2_l <= '1'; g3_h <
= '0'; g3_l <= '1'; and transits to the state of ph_state3.

FIGS. 8A and 8B are state transition diagrams of the PWM generation block 205. FIG. FIG. 8A shows the second standby state.
(wait_2) and the transition between chg_s. In the second wait state (wait_2), the variable pwm_on is reset to zero (const_zero), and in the state of chg_s, the constant speed detection signal is L
PW calculated by control unit 1101 only during OW (sel = 0)
PWM_CNT, which is a value corresponding to the PWM control signal 1214 for controlling the duty width of M, is substituted into pwm_on, and while the constant speed detection signal is HIGH (sel = 1), the constant speed detection signal is high.
This indicates that the value of PWM_CNT immediately before it becomes IGH is used.

When the processing in FIG. 8A is described in VHDL,
In wait_2, pwm_on <= const_zero; is performed, and in chg_s, pwm_on <= PWM_CNT; is performed.

FIG. 8B shows the first wait state (wait_1).
The transition to the state of ramp_up_s2 is shown.
In the state of s2, the value of pwm_max + 1 is set as the PWM cycle, and the value of pwm_count is changed from 0 to pwm_on until the value of pwm_count becomes 0.
(PWM signal 304) is HIGH.

If the processing in FIG. 8B is described in VHDL,
In wait_1, pwm <= '0'; pwm_count <= const_zero; is performed. In T21, Will be performed.

When the assignments for the variables used in FIGS. 8A and 8B are described in VHDL, const_zero << = "0000000000000000"; pwm_max << = "0000000000010000";

In the embodiment described above, the rotor is driven at a fixed PWM duty when the rotor rotates at a constant speed. However, the fixed PWM duty value is modulated by a sine wave or the like at a target period. The phase may be shifted at the time of synchronization.

The timing of transition to the constant velocity region may be detected by counting the number of pulses of the position signal of the linear encoder or the rotor. In this case, in FIG. 5A, the condition for shifting from the ramp_up_s state to the print_s state may be changed.

[Other Embodiments] The above embodiments have been described with respect to an ink jet printer that performs printing in accordance with an ink jet printing method. However, it is apparent that the present invention can be applied to a serial type printing apparatus employing another printing method. There will be.

The present invention is not limited to a recording apparatus, but can be applied to any electronic device having a movable portion that performs scanning at a constant speed.

When the present invention is applied to a printer adopting an ink jet recording system, a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for discharging ink is provided. By using a method in which a change in the state of the ink is caused by energy, it is possible to achieve higher density and higher definition of recording.

The typical structure and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. 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, liquid (ink)
By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding the nucleate boiling to an electrothermal transducer arranged corresponding to the sheet or the liquid path holding the Since thermal energy is generated in the electrothermal transducer and film boiling occurs on the heat-acting surface of the recording head, bubbles in the liquid (ink) corresponding to this drive signal on a one-to-one basis can be formed. It is valid.

By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angle liquid flow path) as disclosed in the above-mentioned respective specifications, The configurations described in U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which the heat acting surface is arranged in a bending region, are also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slot is used as a discharge section of an electrothermal transducer for a plurality of electrothermal transducers, and an opening for absorbing pressure waves of thermal energy is discharged. A configuration based on JP-A-59-138461, which discloses a configuration corresponding to each unit, may be adopted.

Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is determined by combining a plurality of recording heads as disclosed in the above specification. This may be either a configuration satisfying the above requirements or a configuration as a single recording head formed integrally.

In addition to the cartridge-type recording head in which the ink tank is provided integrally with the recording head itself described in the above embodiment, the recording head is electrically connected to the apparatus main body by being mounted on the apparatus main body. A replaceable chip-type recording head, which enables a simple connection and supply of ink from the apparatus main body, may be used.

It is preferable to add recovery means for the printhead, preliminary auxiliary means, and the like to the configuration of the printing apparatus described above, since the printing operation can be further stabilized. Specific examples thereof include capping means for the recording head, cleaning means, pressurizing or suction means, preheating means using an electrothermal transducer or another heating element or a combination thereof. It is also effective to provide a preliminary ejection mode for performing ejection that is different from printing, in order to perform stable printing.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be a single recording head or a combination of plural recording heads. Alternatively, the apparatus may be provided with at least one of full colors by color mixture.

In the embodiments described above, the description is made on the assumption that the ink is a liquid. However, even if the ink solidifies at room temperature or lower, it is possible to use an ink that softens or liquefies at room temperature. Or, in the ink jet method, generally, the temperature of the ink itself is controlled within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range.
It is sufficient that the ink is in a liquid state when the use recording signal is applied.

In addition, in order to positively prevent the temperature rise due to thermal energy as energy for changing the state of the ink from a solid state to a liquid state, the temperature is positively prevented.
Alternatively, in order to prevent evaporation of the ink, ink that solidifies in a standing state and liquefies by heating may be used. In any case, the application of heat energy causes the ink to be liquefied by application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start to solidify when reaching the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used.

In such a case, the ink is disclosed in JP-A-54-5
No. 6847 or Japanese Patent Application Laid-Open No. Sho 60-71260, in which the porous sheet is opposed to the electrothermal converter in a state of being held as a liquid or solid substance in the concave portions or through holes of the porous sheet. It may be. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

The present invention can be applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), but can be applied to a single device (for example, a copying machine, a facsimile). Device).

Further, an object of the present invention is to supply a storage medium (or a recording medium) in which a program code of software for realizing the functions of the above-described embodiments is recorded to a system or an apparatus, and a computer (a computer) of the system or the apparatus. Or a CPU or MPU) reads out and executes the program code stored in the storage medium,
It goes without saying that this is achieved. In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.
In addition, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also based on the instructions of the program code,
The operating system (OS) running on the computer performs part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

Further, after the program code read from the storage medium is written in the memory provided in the function expansion card inserted into the computer or the function expansion unit connected to the computer, the program code is read based on the instruction of the program code. , The CPU provided in the function expansion card or the function expansion unit performs a part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the above-described timing charts (shown in FIGS. 3A to 8B) and state transition diagrams. Become.

[0130]

As described above, according to the present invention, in a region where acceleration / deceleration is performed, a steep acceleration / deceleration is performed in a short time by utilizing the characteristics of the brushless DC motor, and in a region where constant speed movement is performed. Can reduce the change in the rotation speed of the motor according to the accuracy of the reference signal.

When this movement control device is used for controlling the carriage of the printing apparatus, the movement speed of the carriage in the printing area is stabilized, so that unevenness during printing is reduced and steep acceleration / deceleration is possible. Therefore, the width of the recording apparatus in the scanning direction can be reduced, and the entire apparatus can be made compact.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a printer as an embodiment of the present invention.

FIG. 2 is a diagram showing a detailed configuration of a brushless three-phase DC motor driving block 101 in the embodiment of FIG. 1;

FIG. 3A is a graph showing a relationship between speed and time when a CR moves in the embodiment of FIG. 1;

FIG. 3B is a graph showing a relationship between acceleration and time when the CR moves in the embodiment of FIG. 1;

3C is a diagram showing a state of a three-phase brushless DC motor driving signal of the embodiment of FIG. 1;

FIG. 4 is a timing chart showing in detail the state of each signal when shifting from acceleration control to constant velocity control in the embodiment of FIG. 1;

FIG. 5A is a first state transition diagram of a commutation switching control block of the embodiment of FIG. 1;

FIG. 5B is a second state transition diagram of the commutation switching control block of the embodiment in FIG. 1;

FIG. 6A is a first state transition diagram of a second commutation timing generation block of the embodiment of FIG. 1;

FIG. 6B is a second state transition diagram of the second commutation timing generation block of the embodiment of FIG. 1;

FIG. 7 is a state transition diagram of a subroutine ph_gen in FIG. 6B.

FIG. 8A is a state transition diagram of a PWM generation block of the embodiment of FIG. 1;

FIG. 8B is a state transition diagram of a PWM generation block of the embodiment of FIG. 1;

FIG. 9 is a diagram illustrating a schematic configuration of a printer as a reference example.

FIG. 10A is a graph showing a relationship between speed and time when a CR moves in a reference example.

FIG. 10B is a control timing signal diagram of a carriage in a reference example.

FIG. 11A is a diagram showing a DC motor control unit in a reference example.

FIG. 11B is a diagram showing a brushless DC motor control unit in the reference example.

FIG. 12A is a timing chart of a rotor angle detection signal in a reference example.

FIG. 12B is a timing chart of a binarized rotor angle detection signal in the reference example.

FIG. 12C is a phase drive transistor drive timing diagram in a reference example.

FIG. 13 is a truth table of a commutation timing block in a reference example.

[Explanation of symbols]

 101 CR motor control unit 102 Rotor angle detection signal 107 Commutation timing selection block 203 Commutation switching control block 204 Commutation timing switching signal 205 PWM generation block 206 Second commutation timing generation block 207 Commutation timing selection block 301 303 CR operating characteristic curve 304 PWM signal 401 U-phase binarization position signal 402 V-phase binarization position signal 403 W-phase binarization position signal 404 Period counter value of binarization position signal 405 Latch 406 Latch timing 407 Comparison Timing 408 Switching timing 409 Selection signal 410 U-phase power generator signal 411 U-phase GND generator signal 412 V-phase power generator signal 413 V-phase GND generator signal 414 W-phase power generator Generator signal 415 W-phase GND side generator signal 416 PWM signal 1101 Control unit 1101A CPU 1101B ROM 1101C RAM 1102 Bus 1103 Image buffer 1104 External I / F unit 1105 Connection unit 1106 Host 1107 Motor control unit 1111 Carriage motor 1112 Head control unit 1113 Carriage on which recording head is mounted 1114 Carriage motor drive signal 1115 Paper transport (LF) motor 1116 Linear encoder scale 1117 Linear encoder sensor 1118 Position information processing unit 1201 Acceleration area 1202 Recording area 1203 Deceleration area 1204 CR operation characteristics in high-speed recording mode 1205 Operation characteristics of CR in high resolution recording mode 1211 ENB signal 1212 DIR signal 1213 BR Signal 1214 PWM control signal 1215 PWM signal 1301 PWM generation block 1311 Phase current drive block 1312 DC motor 1313 Phase current drive block 1314 Brushless DC motor 1315 Rotor angle detection unit 1316 U phase drive position signal 1317 V phase drive position signal 1318 W-phase drive position signal 1319 Waveform shaping block 1320 U-phase binarization position signal 1321 V-phase binarization position signal 1322 W-phase binarization position signal 1323 Commutation timing generation block 1331 to 1340 Switching element 1401 to 1406 Switching Device drive signal

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C056 EA01 EA23 EB36 EC11 EC31 EC37 EC38 FA03 FA10 2C480 CA01 CA44 CB02 CB35 EA01 EA05 EA06 EA27 EC04 5H303 AA28 BB02 BB07 CC04 DD01 FF04 GG10 LL03 5H560 BB03 JJ05 TT12 TT13 UA10 XA12

Claims (9)

[Claims] 1. A movement control device for controlling movement of a driven body using a brushless DC motor, wherein the angle detection means is attached to the motor and detects an angular position of the motor; First driving means for generating a first driving signal based on a signal from the means; second driving means for generating a second driving signal based on a reference signal having a predetermined frequency; Drive control for driving the motor by the first drive signal in a region where the driving body accelerates and decelerates, and driving the motor by the second drive signal in a region where the driven body moves at a constant speed. And a means for controlling movement. 2. The movement control device according to claim 1, wherein the first and second driving units control the speed of the motor based on an amount of power supplied to the motor per unit time. 3. The movement control device according to claim 1, wherein the first and second drive signals are pulse width modulated signals of a predetermined voltage. 4. The apparatus according to claim 1, wherein said drive control means switches said first drive signal and said second drive signal in synchronization with a signal from said angle detection means. The movement control device according to claim 1. 5. An electronic apparatus using the movement control device according to claim 1. 6. A printing apparatus for performing printing by scanning a carriage equipped with a print head on a print medium based on information transmitted from an external device, wherein the brushless DC motor drives the carriage; An angle detecting unit attached to the motor, for detecting an angular position of the motor; a first driving unit for generating a first driving signal based on a signal from the angle detecting unit; A second drive unit for generating a second drive signal based on a reference signal; and a first drive unit in an area where the carriage performs acceleration / deceleration.
And a drive control means for driving the motor by the second drive signal in a region where the carriage is driven at a constant speed by driving the motor by the drive signal. 7. The recording apparatus according to claim 6, wherein the recording head is an inkjet recording head that performs recording by discharging ink. 8. The printing head according to claim 1, wherein the printing head uses thermal energy to eject ink, and includes a thermal energy converter for generating thermal energy to be applied to the ink. Item 8. The recording device according to Item 7. 9. A movement control method for controlling movement of a driven body using a brushless DC motor, comprising: detecting an angular position of the motor; and a first drive signal based on the detected angular position. Generating a second drive signal based on a reference signal of a predetermined frequency, and driving the motor by the first drive signal in a region where the driven body accelerates / decelerates, A movement control method, wherein the motor is driven by the second drive signal in a region where the driving body performs a constant speed motion.