JP2000249898A - Drive controller and apparatus having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the stop before attaining the target drive quantity of a drive assembly and to prevent the occurrence of the abnormal noise and mechanical bite by reacceleration near the moving end of a driven member by changing acceleration control conditions according to conditions exclusive of the drive residual quantity to the target drive quantity. SOLUTION: Whether the rotating speed of a vibration type motor 212 which is a focus motor is slower than a target speed or whether there is a need for acceleration or not is decided. When the acceleration decision is made and if the drive residual quantity with respect to the target drive quantity is below a prescribed set value, whether the frequency of the present drive signal of the motor 212 is above the prescribed value (f) or not is decided. If the frequency of the drive signal is above (f), the acceleration processing is executed. Namely, a lens CPU 201 sends the data to degrade the frequency of a VCO 203 to a D/A conversion section 202 and lowers the frequency of the drive signal of the motor 212. Unless the acceleration decision is made, the deceleration processing is executed to raise the frequency of the drive signal of the motor 212.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vibration type driving device,
The present invention relates to a drive control device that controls a drive device such as a voltage control drive device or a duty control drive device,
More specifically, the present invention relates to a drive control device that performs acceleration / deceleration control of a drive device that controls the position of a focus lens or the like in a camera or a lens barrel.

[0002]

2. Description of the Related Art In control for driving a motor by a target drive amount by performing acceleration / deceleration control, once an acceleration process (or a deceleration process) is started to prevent a so-called hunting phenomenon in which the motor is repeatedly accelerated and decelerated, the process is started. In order to shift to the deceleration process (or the acceleration process), for example, the condition may be that the deceleration determination (or the acceleration determination) is performed continuously L times.

Further, in order to prevent the motor driving amount from decelerating too much before reaching the target driving amount and stopping just before the desired driving amount cannot be obtained, the motor is driven immediately before stopping (the remaining driving amount is reduced. State), it is configured to facilitate re-acceleration such as performing acceleration processing if acceleration determination is made even once during deceleration.

Here, the configuration and operation of a lens barrel for driving a focus lens by a vibration type driving device will be briefly described. Upon receiving the focus drive command from the camera, the drive control device in the lens barrel applies a drive signal (frequency signal) having a predetermined initial frequency to the electro-mechanical energy conversion element of the vibration type drive device to cause the vibrator to move. Vibrate. Accordingly, the contact body that has come into contact with the vibrating body is rotationally driven, and the drive output activates the lens driving mechanism, and the focus lens starts moving in the optical axis direction. As shown in FIG. 8A, the frequency of the drive signal is scanned from a high frequency to a gradually lower frequency. As the driving frequency decreases, the rotational speed of the vibration type driving device gradually increases, and the moving speed of the focus lens also increases.

The vibration type driving device is provided with a speed detector such as a photo-interrupter which outputs a pulse signal at a period corresponding to the operation speed of the vibration type driving device. The period is set in advance to the period of the pulse signal output from the detector. The frequency of the drive signal is controlled such that the speed of the vibration type driving device reaches the target speed by comparing the target pulse period with the target pulse period. In addition, the number of pulse signals from the detector is counted, and the remaining drive amount up to the target driving amount of the vibration type driving device is calculated by comparing the number of pulse signals corresponding to the target driving amount of the vibration type driving device. You.

When the drive speed reaches the target speed in this way, the acceleration is terminated, and when the number of remaining drive pulses decreases, the drive control device determines that the target drive amount (that is, the target drive position of the focus lens) is approaching. The vibration type driving device is gradually decelerated. A target speed is also set when decelerating, and the target speed is set to be slower as the remaining drive amount decreases. The current rotation speed is calculated from the target speed and the pulse signal width from the speed detector obtained by the rotation of the vibration type driving device, and the operation is performed so that the focus lens is gradually decelerated and stopped at the target driving position.

However, there is a case where the vibration type driving device is excessively decelerated just before the focus lens reaches the target driving position due to a variation in the number of revolutions of the vibration type driving device. In this case, the vibration type driving device may be reaccelerated as shown in FIG. 8 (b). The condition for switching from the deceleration control to the reacceleration control is, for example, such that the acceleration is not accelerated unless acceleration determination is continued for a predetermined number of times. If a condition in which acceleration switching is difficult is set, the focus lens may be stopped before reaching the target drive position without being able to accelerate.

On the other hand, if control is performed so that re-acceleration is easily performed during deceleration control, hunting in which acceleration and deceleration are repeated unnecessarily occurs when the target speed is reached and driving is performed at a constant speed. Drive becomes unstable.

Therefore, as shown in FIG. 8C, during normal driving (when the remaining driving amount is equal to or more than K), it is set so that acceleration is difficult.
If the remaining drive amount to the target position is small (the remaining drive amount is K
In the following case, the re-acceleration is set to be easy so that when the remaining drive amount is K or more, constant speed control can be performed stably without hunting of acceleration and deceleration, and immediately before the target drive amount is reached (the remaining drive amount K or less). Then, it is conceivable that even if the vehicle is decelerated excessively, it is possible to prevent the vehicle from stopping before reaching the target drive amount by re-acceleration immediately.

[0010]

However, in the control system which facilitates re-acceleration immediately before reaching the target drive amount,
If a mechanism for detecting the mechanical movement end of the focus lens and forcibly stopping the drive is not provided, FIG.
As shown in (a) and (b), a pulse signal is output from the speed detector even when the vehicle is approaching a stop after being decelerated to the vicinity of the moving end, and the pulse width of the pulse signal is large. Is to perform an acceleration process. When the acceleration process is performed near the moving end, the lens collides with the moving end to cause abnormal noise, mechanical intrusion, and the like.

According to the present invention, it is possible to reliably prevent the drive unit from stopping before reaching the target drive amount, and to prevent generation of abnormal noise and mechanical biting due to re-acceleration near the moving end of a member driven by the drive unit. It is an object of the present invention to provide a drive control device capable of preventing such a problem.

[0012]

In order to achieve the above object, according to the present invention, when a predetermined remaining acceleration control condition is satisfied after a remaining driving amount of a driving device up to a target driving amount becomes a predetermined amount or less. In the drive control device for performing the acceleration control of the drive device, the acceleration control condition is changed according to the drive condition of the drive device other than the remaining drive amount up to the target drive amount.

Specifically, the detection of the actual driving state of the driving device is repeated, and it is determined whether or not to perform the acceleration control of the driving device according to each detection result, and the driving signal (frequency signal) of the vibration type driving device is determined. ) According to the condition regarding the frequency, the condition regarding the driving voltage (applied voltage) of the voltage control type driving device or the condition regarding the duty value of the duty control type driving device.
The required number of acceleration determinations as the acceleration control condition is changed.

More specifically, the required number of times when the frequency of the drive signal of the vibration type driving device is equal to or higher than a predetermined frequency is set to be smaller than the required number when the frequency is lower than the predetermined frequency. Further, the required number of times when the drive voltage of the voltage control type driving device is equal to or lower than the predetermined voltage is set to be smaller than the required number of times when the drive voltage exceeds the predetermined voltage. Further, the required number of times when the on-duty value of the applied pulse signal of the duty control type driving device is equal to or less than the predetermined duty value is set to be smaller than the required number when the on-duty value exceeds the predetermined duty value.

That is, when the driving device is likely to be stopped before reaching the target driving amount due to excessive deceleration, the number of required acceleration determinations is set as small as 1 or m continuous times to facilitate switching to the acceleration control. . This reliably prevents the driving device from stopping before being driven to the target driving amount.

On the other hand, the necessary number of times of acceleration determination immediately before the moving member driven by the driving device reaches the mechanical moving end or the like is set to n (n> m) continuous times, thereby making it difficult to switch to acceleration control. . This reduces the speed at which the moving member comes into contact with the moving end, thereby suppressing the generation of abnormal noise and mechanical biting.

[0017]

(First Embodiment) First, FIG. 2 shows a configuration of a drive control device of a vibration type motor (vibration type driving device) according to a first embodiment of the present invention. In this figure, a lens CPU 201 is a camera CPU 217
And a contact 216. The lens CPU 201 and the camera CPU 217 communicate with each other through this terminal, and the camera stops driving of a focus motor and an aperture, requests transmission of lens data, and the like. Lens CPU
201 performs processing according to a command from the camera CPU 217.

The lens CPU 201 is a camera CPU 217
When a drive command for the focus motor is received from the CPU, predetermined data is sent to the D / A converter 202 so that a predetermined initial frequency for starting driving of the vibration motor 212 as the focus motor is obtained. D / A converter 202
A voltage-frequency converter (hereinafter referred to as VCO) 2 which converts a voltage value corresponding to digital data from the lens CPU 201
03 is output.

The VCO 203 sends a signal having a frequency corresponding to the input voltage value to the frequency divider / phase shifter 204. The frequency divider / phase shifter 204 responds to the frequency signal from the VCO 203
A rectangular wave having a phase difference of two 90 degrees or 270 degrees, OUT and BOUT, is output.

From the lens CPU 201 to the frequency divider / phase shifter 20
4 is used to determine the rotation direction of the vibration motor 212, and AOUT, B
The phase difference of OUT can be changed between 90 degrees and 270 degrees.

The USM ON / OFF signal sent from the lens CPU 201 to the frequency divider / phase shifter 204 turns on / off the vibration type motor 212. In response to this signal, the frequency divider / phase shifter 204 causes AOUT, BOUT It operates to turn on / off the signal output.

The rectangular waves AOUT and BOUT output from the frequency divider / phase shifter 204 are amplified by power amplifiers 205 and 206 into voltages and currents that can drive the vibration type motor 212.

A amplified by power amplifiers 205 and 206
OUT and BOUT signals are output from the matching coils 207 and 20.
8, and is supplied as so-called A-phase and B-phase drive signals of the vibration type motor 212.

When the A-phase and B-phase drive signals are supplied to the vibration-type motor 212, the vibration-type motor 212 rotates in a direction corresponding to the A-phase and B-phase drive signals. When the motor 212 rotates, the pulse plate 213 rotates, and a signal corresponding to the rotation is output from the photo interrupter 214. The signal from the photo interrupter 214 is amplified and shaped by the detection circuit 215 and sent to the lens CPU 201. Lens C
PU 201 counts this pulse, and the camera CPU 2
It is determined whether or not the drive amount sent from 17 has been reached, and the drive / stop of the vibration type motor 212 is controlled.

The speed of the motor is calculated from the width of the pulse signal of the photointerrupter 214 shaped by the detection circuit 215 and compared with the target speed stored in the lens CPU 201. If the current speed is slower than the target speed. For example, data is sent to the D / A converter 202 so as to accelerate the vibration type motor 212, and the frequency of the drive signal supplied to the vibration type motor 212 is reduced. Also, if the current speed is higher than the target speed, D / D
The data is transmitted to the A converter 202 and the vibration type motor 212
Is controlled to increase the frequency of the drive signal supplied to.

In controlling the vibration type motor 212, in order to avoid a phenomenon in which the rotation of the motor suddenly decreases,
So-called phase control is also performed. An A-phase signal, which is one of the drive signals for driving the vibration motor 212, is used by a first comparison circuit 209 for waveform shaping for use in phase control.
Sent to The vibration type motor 212 is provided with a vibration detection element, and a detection signal (hereinafter, referred to as an S phase) is also sent to the second comparison circuit 210 for waveform shaping so as to be used for phase control.

A predetermined reference voltage is supplied to one of the two input terminals of each of the two comparison circuits 209 and 210. The reference voltage is compared with A-phase and S-phase signals. Output a square wave.

The phase detector 211 counts, for example, the number of clocks from the rise of the signal of the first comparator 209 to the rise of the signal of the second comparator 210, and sends the count value to the lens CPU 201.

The lens CPU 201 detects the phase difference between the A phase and the S phase based on the output from the phase detector 211. The D / A converter 2 according to the detected phase difference
02 is changed, and the frequency of the drive signal for driving the vibration motor 212 is changed.

Next, the operation of the drive control device configured as described above will be described with reference to the flowchart of FIG. The program shown in this flowchart is held in the lens CPU 201.

# 101: contact 2 from camera CPU 217
The lens CPU 201 analyzes a command transmitted through the camera 16 and determines whether or not the command is an AF (autofocus) driving command. If it is an AF driving command, the process proceeds to # 102, where A
If it is not the F drive command, the process proceeds to # 104.

# 102: The number of drive pulses (target drive amount) of the AF drive command is read.

# 103: The focus motor is driven.

# 104: Perform processing corresponding to a command other than the AF drive command.

# 105: It is checked whether or not the pulse output through the photo interrupter 214 is output for a predetermined time or more by the rotation of the pulse plate 213 in conjunction with the rotation of the vibration motor 212. If a pulse is not output for a predetermined time, it is determined that there has been some accident, such as being pressed by hand, and the flow proceeds to # 107. If the pulse is output within the predetermined time, it is determined that the motor 212 has started to rotate, and the process proceeds to # 106.

# 106: Count the number of pulses.

# 107: It is determined that some accident has occurred, and a drive impossible flag is set. The information about the inability to drive is transmitted to the camera as information in response to a request from the camera.

# 108: It is determined whether the drive amount of the motor 212 has reached the target drive amount (whether the focus lens has reached the target drive position) based on the number of pulses counted in # 106. If the target drive amount has been reached, the process proceeds to # 117, and if the target drive amount has not been reached, the process proceeds to # 109.

# 109: A phase, S of vibration type motor 212
It is determined whether the phase relationship between the phases has reached a predetermined phase relationship, or whether the rotation speed of the motor 212 calculated from the pulse width of the pulse signal from the photo interrupter 214 has reached a target value. When the phase relationship is a predetermined phase relationship or when the rotation speed has reached the target value, the frequency of the drive signal is maintained to maintain the current speed. When it is determined that the speed is maintained, the process returns to the process of checking whether the next pulse is output from the photo interrupter 214 of # 105 within a predetermined time. If the phase relationship is not the predetermined phase relationship and the rotation speed is not the target speed, the process proceeds to # 110.

# 110: The speed calculated from the pulse width is compared with the target speed, and it is determined whether the current speed is lower than the target speed, that is, whether it is necessary to accelerate. When the acceleration is determined, the routine proceeds to step # 112. When the acceleration is not determined, the routine proceeds to step # 112.
Go to 111.

# 111: This processing is performed when neither the current speed maintenance judgment nor the acceleration judgment is made. Here, since the current speed is higher than the target speed, it is necessary to decelerate. However, it is determined whether or not this deceleration determination has been performed n times, that is, whether or not the process of this step has been performed n times. If the deceleration determination is not continuous n times, the process of # 105 is performed, and if the deceleration process is continuous n times, the process proceeds to # 116.

# 112: It is determined whether or not the remaining drive amount is less than a certain set value K with respect to the target drive pulse number specified by the AF drive command from the camera. When the remaining drive amount is equal to or smaller than K, the process proceeds to # 113, and when it is larger than K, the process proceeds to # 114.

# 113: Acceleration determination is made in # 110,
When the remaining drive amount is equal to or smaller than K, this process is performed. Here, it is determined whether the frequency of the current drive signal of the vibration motor 212 is equal to or higher than a predetermined value f1. The frequency of the drive signal is f
If it is 1 or more, proceed to # 115; if less than f1, # 114
Proceed to.

# 114: An acceleration determination is made in # 110,
This processing is performed when the remaining drive amount is larger than K or the remaining drive amount is equal to or less than K and the frequency of the drive signal is less than f1. Here, it is determined whether or not the acceleration determination by # 110 is continuous for n times. When the acceleration determination is performed n times consecutively, # 115
On the other hand, if it is not consecutive n times, the process returns to step # 105.

# 115: An acceleration process is performed. In particular,
The lens CPU 201 sends a VC signal to the D / A converter 202.
Data for lowering the frequency of O203 is transmitted, and the frequency of the drive signal of the vibration motor 212 is reduced.

# 116: A deceleration process is performed. In particular,
The lens CPU 201 sends a VC signal to the D / A converter 202.
Data for increasing the frequency of O203 is transmitted, and the frequency of the drive signal of the vibration motor 212 is increased.

# 117: The driving of the motor 212 is stopped.

Here, the pulse signal from the photo interrupter 214 in the above control and the vibration type motor 212
Of the drive signal (drive frequency) of the vibration type motor 2
FIGS. 3A and 3B show the relationship between the rotation speed and the rotation speed of No. 12. FIG.

At the left end in the figure, the driving of the vibration type motor 212 is started, and thereafter, the acceleration control (control for lowering the driving frequency), the constant speed control (maintenance control for the driving frequency), and the deceleration control (rising for the driving frequency). Control). When the drive amount of the vibration motor 212 reaches a position near the target drive amount (here, the mechanical movement end of the focus lens), that is, a position where the remaining drive amount becomes K or less, the deceleration proceeds and the pulse A pulse signal having a large width is output from the photo interrupter 214.

At this time, as shown in FIG. 3A, when the drive frequency is equal to or higher than f1, that is, when the vehicle is decelerated excessively, the immediate acceleration process is performed by one acceleration determination.
This can prevent the vibration motor 212 from stopping before reaching the target drive amount (before the focus lens reaches the moving end).

Then, when the acceleration is re-accelerated to some extent and the driving frequency falls below f1, the acceleration process is not executed unless the acceleration determination is continued n times, so that gradual acceleration control or speed maintenance control is performed. . Therefore, the speed at which the focus lens collides with the mechanical end becomes slower than before, and it is possible to suppress generation of abnormal noise and mechanical digging.

On the other hand, as shown in FIG. 3B, when the drive amount of the vibration motor 212 reaches a position near the target drive amount and the drive frequency is smaller than f1, the acceleration determination is performed n times. If not continuous, the acceleration processing is not executed, and therefore the acceleration processing is not performed or the gentle acceleration processing is performed, so that generation of abnormal noise and mechanical digging can be suppressed in the same manner as described above.

As described above, according to the present embodiment, the vibration type motor 212 is used as a focus motor, and when the remaining drive amount becomes a predetermined value or less, the condition for re-acceleration is set according to the drive frequency. I am going to change it,
The focus lens does not stop immediately before the target stop position, and it is possible to suppress generation of abnormal noise and mechanical biting when the focus lens hits the mechanical end.

In the present embodiment, the case where the required number of times of the acceleration determination and the deceleration determination as the condition for performing the acceleration processing or the deceleration processing is the same has been described. Is also good.

Further, in the present embodiment, the case where the required number of acceleration determinations is set to one as a condition for performing the acceleration process when the remaining drive amount is equal to or less than K and the drive frequency is equal to or more than f1 has been described. May be m consecutive times, which is less than the necessary number of consecutive times, which is the required number of times when f is smaller than f1.

The conditions for performing the acceleration and deceleration processing when the remaining drive amount is larger than K and the conditions for performing the acceleration and deceleration processing when the remaining drive amount is equal to or less than K and the drive frequency is smaller than f1 are as follows. They may be the same or different.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention.
4 shows an operation flowchart of a drive control device of the drive device according to the embodiment. In the present embodiment, a voltage control type motor is used in which the applied voltage is increased when the focus motor is accelerated and the applied voltage is decreased when the focus motor is decelerated.

# 501: The lens side analyzes the command sent from the camera side, and analyzes whether it is an AF (autofocus) drive command. If it is an AF driving command, # 50
The process proceeds to step # 2, and if not, the process proceeds to step # 504.

# 502: The number of drive pulses (target drive amount) of the AF drive command is read.

# 503: The focus motor is driven.

# 504: Perform processing corresponding to a command other than the AF drive command.

# 505: It is checked whether or not the pulse output through the photo interrupter is output for a predetermined time or more by the rotation of the pulse plate in conjunction with the rotation of the focus motor. If a pulse is not output for a predetermined time, it is determined that some accident has occurred, such as pressing by hand, and the process proceeds to # 507. If the pulse is output within the predetermined time, it is determined that the motor 212 has started to rotate, and the process proceeds to # 506.

# 506: The number of pulses is counted.

# 507: It is determined that some accident has occurred, and the drive impossible flag is set. The information about the inability to drive is transmitted to the camera as information in response to a request from the camera.

# 508: It is determined from the number of pulses counted in # 506 whether the motor drive amount has reached the target drive amount (whether the focus lens has reached the target drive position). If the target drive amount has been reached, proceed to # 517,
If the target drive amount has not been reached, the routine proceeds to step # 509.

# 509: It is determined whether or not the rotation speed of the motor calculated from the pulse width of the pulse signal from the photo interrupter has reached the target value. If the rotation speed has reached the target value, the current speed is maintained. If it is determined that the speed is to be maintained, the process returns to the step of checking whether the next pulse is output from the photo interrupter # 505 within a predetermined time. If the rotation speed is not the target speed, the process proceeds to # 510.

# 510: The speed calculated from the pulse width is compared with the target speed, and it is determined whether the current speed is lower than the target speed, that is, whether it is necessary to accelerate. When acceleration is determined, # 512; when acceleration is not determined, #
Proceed to 511.

# 511: This processing is performed when neither the current speed maintenance judgment nor the acceleration judgment is made. Here, since the current speed is higher than the target speed, it is necessary to decelerate. However, it is determined whether or not this deceleration determination has been performed n times, that is, whether or not the process of this step has been performed n times. If the deceleration determination is not continuous n times, the process of # 505 is performed, and if the deceleration process is continuous n times, the process proceeds to # 516.

# 512: It is determined whether or not the remaining drive amount is equal to or less than a certain set value K with respect to the target drive pulse number specified by the AF drive command from the camera. When the remaining drive amount is equal to or smaller than K, the process proceeds to # 513, and when it is larger than K, the process proceeds to # 514.

# 513: An acceleration determination is made in # 510,
When the remaining drive amount is equal to or smaller than K, this process is performed. Here, it is determined whether or not the current drive voltage of the motor is equal to or less than a predetermined value V1. If the drive voltage is equal to or lower than V1, the process proceeds to # 515, where V
If it is larger than 1, the process proceeds to # 514.

# 514: An acceleration determination is made in # 510,
This processing is performed when the remaining drive amount is larger than K or the remaining drive amount is equal to or less than K and the drive voltage is larger than V1. Here, it is determined whether or not the acceleration determination in # 510 is continuous n times. When the acceleration determination has been performed n times, the process proceeds to step # 515.
If not, the process returns to step # 505.

# 515: The acceleration process is performed. In particular,
Increase the drive voltage of the focus motor.

# 516: A deceleration process is performed. In particular,
Reduce the drive voltage of the focus motor.

# 517: The driving of the focus motor is stopped.

Here, the relationship among the pulse signal from the photo interrupter, the drive voltage of the focus motor, and the rotation speed of the focus motor in the above control is shown in FIG.
(B). Note that the relationship between the drive voltage and the rotation speed is approximately proportional. FIG. 5A shows the result of the conventional control.

At the left end in the figure, driving of the focus motor is started, and thereafter, acceleration control (drive voltage increase control),
The control enters deceleration control (driving voltage reduction control) through constant speed control (driving voltage maintenance control). Then, the vicinity of the position where the drive amount of the focus motor becomes the target drive amount (here, the mechanical movement end of the focus lens), that is, the remaining drive amount is K
When the following position is reached, deceleration proceeds, and a pulse signal having a large pulse width is output from the photo interrupter.

At this time, as shown in FIG. 5B, when the drive voltage is equal to or lower than V1, that is, when the vehicle is decelerated excessively, the immediate acceleration process is performed by one acceleration determination. Thus, it is possible to prevent the focus motor from stopping before reaching the target drive amount (before the focus lens reaches the moving end). In this regard, the same applies to FIG.

However, when the vehicle is accelerated to some extent and the driving voltage becomes higher than V1, as shown in FIG.
The speed at which the focus lens collides with the mechanical end increases,
Abnormal noise and mechanical biting occur.

On the other hand, according to the present embodiment, FIG.
As shown in (b), after the drive voltage becomes higher than V1, the acceleration process is not executed unless the acceleration determination is continued for n times, so that a gradual acceleration control or speed maintenance control is performed. Therefore, the speed at which the focus lens collides with the mechanical end becomes slower than before, and it is possible to suppress generation of abnormal noise and mechanical digging.

As described above, according to the present embodiment, when the voltage control type motor is used as the focus motor, and when the remaining drive amount becomes a predetermined value or less, the condition for re-acceleration is set according to the drive voltage. Since the focus lens is changed, the focus lens does not stop immediately before the target stop position, and it is possible to suppress generation of abnormal noise and mechanical digging when the focus lens hits the mechanical end.

In this embodiment, the case where the required number of times of the acceleration determination and the deceleration determination as the condition for performing the upper acceleration processing or the deceleration processing is the same is described. May be changed.

Further, in the present embodiment, the case where the necessary number of acceleration determinations is set to one as a condition for performing the acceleration process when the remaining drive amount is K or less and the drive voltage is V1 or less has been described. May be set to m consecutive times, which is less than the necessary number of consecutive times, that is, the required number of times when is larger than V1.

The conditions for performing the acceleration and deceleration processing when the remaining drive amount is larger than K and the conditions for performing the acceleration and deceleration processing when the remaining drive amount is equal to or less than K and the drive voltage is equal to or more than V1 are as follows. They may be the same or different.

(Third Embodiment) FIG. 6 shows a third embodiment of the present invention.
4 shows an operation flowchart of a drive control device of the drive device according to the embodiment. In the present embodiment, a duty (PWM control) type motor is used in which a focus motor increases the on-duty value when accelerating and decreases the on-duty value when decelerating.

# 601: The command sent from the camera is analyzed on the lens side, and it is analyzed whether it is an AF (autofocus) drive command. If it is AF driving command, # 60
The process proceeds to step # 2, and if not, the process proceeds to step # 604.

# 602: The number of drive pulses (target drive amount) of the AF drive command is read.

# 603: The focus motor is driven.

# 604: Perform processing in accordance with a command other than the AF drive command.

# 605: It is checked whether or not the pulse output through the photo interrupter is output for a predetermined time or more by the rotation of the pulse plate in conjunction with the rotation of the focus motor. If a pulse is not output for a predetermined time, it is determined that there has been some kind of accident, such as being pressed by hand, and the flow proceeds to # 607. If the pulse is output within the predetermined time, it is determined that the motor 212 has started to rotate, and the process proceeds to # 606.

# 606: Count the number of pulses.

# 607: It is determined that some accident has occurred, and the drive disable flag is set. The information about the inability to drive is transmitted to the camera as information in response to a request from the camera.

# 608: It is determined from the number of pulses counted in # 606 whether the motor drive amount has reached the target drive amount (whether the focus lens has reached the target drive position). If the target drive amount has been reached, proceed to # 617,
If the target drive amount has not been reached, the process proceeds to # 609.

# 609: It is determined whether or not the rotation speed of the motor calculated from the pulse width of the pulse signal from the photo interrupter has reached the target value. If the rotation speed has reached the target value, the current speed is maintained. If it is determined that the speed is to be maintained, the process returns to the step of checking whether the next pulse is output from the photo interrupter of # 605 within a predetermined time. If the rotation speed is not the target speed, the process proceeds to step # 610.

# 610: The speed calculated from the pulse width is compared with the target speed, and it is determined whether the current speed is lower than the target speed, that is, whether it is necessary to accelerate. When the acceleration is determined, the process proceeds to step # 612. When the acceleration is not determined, the process proceeds to step # 612.
Proceed to 611.

# 611: This processing is performed when neither the current speed maintenance judgment nor the acceleration judgment is made. Here, since the current speed is higher than the target speed, it is necessary to decelerate. However, it is determined whether or not this deceleration determination has been performed n times, that is, whether or not the process of this step has been performed n times. If the deceleration determination is not continuous n times, the process of # 605 is performed, and if the deceleration process is continuous n times, the process proceeds to # 616.

# 612: It is determined whether or not the remaining drive amount is equal to or less than a certain set value K with respect to the target drive pulse number specified by the AF drive command from the camera. When the remaining drive amount is equal to or smaller than K, the process proceeds to # 613, and when it is larger than K, the process proceeds to # 614.

# 613: An acceleration determination is made in # 610,
When the remaining drive amount is equal to or smaller than K, this process is performed. Here, it is determined whether the current on-duty value of the drive pulse of the motor is equal to or less than a predetermined value D1. If the on-duty value is equal to or less than D1, the process proceeds to # 615, and if the on-duty value is greater than D1, the process proceeds to # 614.

# 614: An acceleration determination is made in # 610,
This processing is performed when the remaining drive amount is larger than K or the remaining drive amount is equal to or smaller than K and the on-duty value is larger than D1. Here, it is determined whether or not the acceleration determination in # 610 is n times continuous. # 6 when the acceleration judgment is repeated n times
If the number of times is not n, the process returns to step # 605.

# 615: An acceleration process is performed. In particular,
Increase the on-duty value of the drive pulse of the focus motor.

# 616: A deceleration process is performed. In particular,
Decrease the on-duty value of the drive pulse of the focus motor.

# 617: The drive of the focus motor is stopped.

FIG. 7 (b) shows the relationship among the pulse signal from the photo interrupter, the on-duty value of the drive pulse of the focus motor, and the rotation speed of the focus motor in the above control. FIG. 7 (a)
Is based on conventional control.

At the left end in the figure, driving of the focus motor is started, and thereafter, acceleration control (increase control of the on-duty value) and constant speed control (control of maintaining the on-duty value)
After that, the process enters the deceleration control (control for reducing the on-duty value). When the drive amount of the focus motor reaches a position near the target drive amount (here, the mechanical movement end of the focus lens), that is, a position where the remaining drive amount becomes K or less, the deceleration proceeds, and the pulse width decreases. A large pulse signal is output from the photo interrupter.

At this time, as shown in FIG. 7B, when the on-duty value is equal to or less than D1, that is, when the vehicle is decelerated excessively, immediate acceleration processing is performed by one acceleration determination. Thus, it is possible to prevent the focus motor from stopping before reaching the target drive amount (before the focus lens reaches the moving end). In this regard, FIG.
The same applies to (a).

However, when the acceleration is re-accelerated to some extent and the on-duty value becomes larger than D1, as shown in FIG. The speed of colliding with the edge is increased, causing abnormal noise and mechanical digging.

On the other hand, according to the present embodiment, FIG.
As shown in (b), after the on-duty value becomes larger than D1, acceleration processing is not executed unless acceleration determination is continued n times, so that gentle acceleration control or speed maintenance control is performed. Therefore, the speed at which the focus lens collides with the mechanical end becomes slower than before, and it is possible to suppress generation of abnormal noise and mechanical digging.

As described above, according to the present embodiment, the duty control type motor is used as the focus motor, and when the remaining drive amount becomes equal to or less than the predetermined value, the duty control type motor is restarted according to the on-duty value of the drive pulse. Since the conditions for acceleration are changed, the focus lens does not stop just before the target stop position, and it is possible to suppress the generation of abnormal noise and mechanical biting when it hits the mechanical end. it can.

In the present embodiment, a case has been described in which the required number of times of the acceleration determination and the deceleration determination as the control transition condition to the acceleration processing or the deceleration processing is the same. You may change it.

Further, in the present embodiment, the case where the necessary number of acceleration determinations is set to 1 as the condition for performing the acceleration process when the remaining drive amount is K or less and the on-duty value is D1 or less has been described. The number of consecutive times may be m, which is smaller than the necessary number of times n, which is the required number of times when the duty value is larger than D1.

The conditions for performing the acceleration and deceleration processing when the remaining driving amount is larger than K and the conditions for performing the acceleration and deceleration processing when the remaining driving amount is equal to or less than K and the driving voltage is equal to or higher than V1 are as follows. They may be the same or different.

Further, in this embodiment, the control of the driving device for driving the lens barrel or the focus lens of the camera has been described. However, the drive control device of the present invention is applicable to the case of driving the lens barrel or the zoom lens of the camera. Also, the present invention can be applied to a case where an optical element and other moving members are driven and controlled in a device other than a lens barrel or a camera.

[0112]

As described above, according to the present invention, the acceleration control condition for performing the acceleration control of the drive device after the remaining drive amount of the drive device up to the target drive amount has become a predetermined amount or less, Change according to conditions other than the remaining drive amount up to the target drive amount (for example, conditions related to the drive frequency of the vibration type drive device, conditions related to the drive voltage of the voltage control type drive device, or conditions related to the duty value of the duty control type drive device) I am trying to do it. For this reason, according to the present invention, when there is a possibility that the driving device is stopped before reaching the target driving amount due to excessive deceleration, the acceleration control conditions are relaxed, and the driving device is easily switched to the acceleration control. Can be reliably prevented from stopping before being driven to the target drive amount. On the other hand, the acceleration control conditions immediately before the moving member driven by the driving device reaches the moving end are made stricter,
Since it is difficult to switch to the acceleration control, it is possible to reduce the speed at which the moving member comes into contact with the mechanical moving end, and suppress occurrence of abnormal noise and mechanical biting.

[Brief description of the drawings]

FIG. 1 is an operation flowchart of a drive control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of the drive control device.

FIG. 3 is a diagram illustrating a relationship among a pulse signal from a photo interrupter, a driving frequency of a vibration type motor, and a rotation speed of the vibration type motor in the drive control device.

FIG. 4 is an operation flowchart of a drive control device according to a second embodiment of the present invention.

FIG. 5 is a relationship diagram between a pulse signal from a photo interrupter and a drive voltage (motor rotation speed) of a voltage control type motor in a conventional drive control device and the drive control device of the second embodiment.

FIG. 6 is an operation flowchart of a drive control device according to a third embodiment of the present invention.

FIG. 7 is a diagram showing a relationship between a pulse signal from a photo interrupter and a drive duty value of a duty control type motor in the conventional drive control device and the drive control device of the third embodiment. FIG. 3 is a diagram illustrating a relationship between a pulse signal from a photo interrupter and a motor rotation speed in the drive control device.

FIG. 8 shows a pulse signal from a photo-interrupter in a conventional drive control device, a drive frequency of a vibration type motor,
FIG. 4 is a diagram illustrating a relationship with a rotation speed of a vibration type motor.

FIG. 9 shows a pulse signal from a photo interrupter in a conventional drive control device, a drive frequency of a vibration type motor,
FIG. 4 is a diagram illustrating a relationship with a rotation speed of a vibration type motor.

[Explanation of symbols]

 201: lens CPU 202: D / A converter 203: voltage-frequency converter 212: vibration type motor (AF motor) 213: rotating plate 214: photo interrupter 215: pulse detector 217: camera CPU

Claims (17)

[Claims] 1. A drive control device for performing acceleration control of the driving device when a predetermined remaining acceleration control condition is satisfied after a remaining driving amount of the driving device up to a target driving amount becomes equal to or less than a predetermined amount. A drive control device that changes the acceleration control condition according to a condition other than the remaining drive amount up to the target drive amount among the conditions related to the drive. 2. The method according to claim 1, further comprising: repeatedly detecting the actual driving state of the driving device to determine whether to perform acceleration control of the driving device in accordance with each detection result. The drive control device according to claim 1, wherein a required number of times of acceleration determination as the acceleration control condition is changed according to a condition other than the remaining drive amount up to the amount. 3. The required number of times of acceleration determination as the acceleration control condition is changed once or between m consecutive times and n consecutive times (n> m). Drive control device. 4. The driving device applies a frequency signal to an electro-mechanical energy conversion element to excite vibration in a vibrating body,
2. A vibration-type driving device that relatively drives the vibrating body and a contact body that comes into contact with the vibrating body, wherein the acceleration control condition is changed according to a condition related to a frequency of the frequency signal. 3. The drive control device according to claim 1. 5. A condition relating to the frequency of the frequency signal is determined by repeating detection of an actual driving state of the vibration-type driving device and performing acceleration control of the vibration-type driving device according to each detection result. The drive control device according to claim 4, wherein a required number of times of acceleration determination as the acceleration control condition is changed according to the following. 6. The method according to claim 1, wherein it is determined whether or not the frequency of the frequency signal is equal to or higher than a predetermined value, and the required number of times when the frequency is equal to or higher than the predetermined frequency is made smaller than the required number when the frequency is lower than the predetermined frequency. 6. The drive control device according to 5. 7. The required number of times when the frequency of the frequency signal is equal to or higher than a predetermined frequency is set to once or m consecutive times, and when the frequency is less than the predetermined frequency is set to continuous n times (n> m). The drive control device according to claim 6, wherein: 8. The voltage control type driving device, wherein the driving device is driven at a speed according to an applied voltage, wherein the acceleration control condition is changed according to a condition related to the applied voltage. Item 2. The drive control device according to item 1. 9. A condition regarding the applied voltage is determined by repeating detection of an actual driving state of the voltage control type driving device and performing acceleration control of the voltage control type driving device according to each detection result. 9. The drive control device according to claim 8, wherein a required number of times of the acceleration determination as the acceleration control condition is changed according to the following. 10. The method according to claim 9, wherein it is determined whether or not the applied voltage is equal to or more than a predetermined value, and the required number of times when the applied voltage is equal to or less than the predetermined voltage is made smaller than the required number of times when exceeding the predetermined voltage. The drive control device according to any one of the preceding claims. 11. The method according to claim 1, wherein the required number of times when the applied voltage is equal to or lower than a predetermined voltage is set to once or m consecutive times, and the required number of times when the applied voltage exceeds the predetermined voltage is set to continuous n times (n> m). The drive control device according to claim 10, wherein 12. A duty control type driving device, wherein the driving device is driven at a speed according to a duty value of an applied pulse signal, and wherein the acceleration control condition is changed according to a condition relating to the duty value. The drive control device according to claim 11, wherein: 13. A condition relating to the duty value is determined by repeating detection of an actual driving state of the duty control type driving device, and determining whether to perform acceleration control of the duty control type driving device according to each detection result. 9. The drive control device according to claim 8, wherein a required number of times of the acceleration determination as the acceleration control condition is changed according to the following. 14. A method for determining whether an on-duty value of the applied pulse signal is equal to or less than a predetermined duty value, and reducing the required number of times when the applied pulse signal is equal to or less than the predetermined duty value to the required number of times when exceeding the predetermined duty value. The drive control device according to claim 13, wherein: 15. The required number of times when the on-duty value is equal to or less than a predetermined duty value is one or m continuous times, and the required number of times when the on-duty value exceeds a predetermined duty value is continuous n (n> m) times. 2. The method according to claim 1, wherein
5. The drive control device according to 4. 16. An apparatus comprising: the drive control device according to claim 1; and a moving member driven by the drive device. 17. The apparatus according to claim 16, wherein the moving member is a focus lens.