JP2004279709A - Motor controller for optical equipment and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To start driving another motor in a period when an electromagnetic motor is braked, in an optical equipment using two or more motors and having at least one electromagnetic motor. <P>SOLUTION: A DC motor driving circuit 23 for driving a DC motor 30, and a driver 34 for driving a stepping motor 34 are connected to a battery 27. A variable power lens 12 is driven by the DC motor 30, and a focus lens 16 is driven by the stepping motor 34. When a zoom switch 42 is switched from an on-state to an off-state, the DC motor 30 is braked in accordance with instructions from a microcomputer 22, then, the regenerative current generated by this flows back to the battery 27. And the stepping motor 34 is started in a period when the regenerative current flows back to the battery 27. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a plurality of motor control devices used in an optical device such as a camera and a control method therefor.
[0002]
[Prior art]
2. Description of the Related Art A conventional camera or the like has two driving motors each for a variable power lens and a focusing lens constituting a photographic lens. There is also a method of driving the focusing lens drive motor during zooming. However, since the two motors, the zooming lens drive motor and the focusing lens drive motor, are simultaneously energized and driven simultaneously, The capacity of the battery for supplying power to the motor needs to be large enough to start two motors at the same time.
[0003]
To solve this problem, for example, a motor control method and apparatus that can simultaneously drive two motors without increasing the battery capacity by time-divisionally driving two motors are known (for example, Patent Document 1).
[0004]
[Patent Document 1]
JP-A-6-138358
FIG. 8 is a diagram showing a typical drive circuit of a DC (direct current) motor.
[0005]
In FIG. 8, both ends of a DC motor 1 are connected to a battery 2 as a DC power supply via a switch S composed of a transistor. Further, a series circuit of a diode D and a resistor R of the illustrated polarity is connected to both ends of the DC motor 1.
[0006]
In the driving circuit having such a configuration, the switch S is turned on and off by operating the pulse control signal. As the on-time increases, the energization time also increases, and the speed of the DC motor 1 increases.
[0007]
When the switch S is turned off during rotation, the DC motor 1 becomes a generator. Then, the voltage polarity of the DC motor 1 is reversed, and the generated current is switched from the loop indicated by the solid line a in the drawing to the loop indicated by the broken line b in the drawing. That is, the current flows through the return circuit formed by the DC motor 1, the diode D, and the resistor R. In this case, the resistance R becomes a load of the DC motor 1 and the generated power is consumed by the resistance R in the form of heat, so that the DC motor 1 can be stopped quickly.
[0008]
FIG. 9 is a timing chart for explaining the operation of such a conventional motor drive circuit.
[0009]
As described above, the two motors are time-divisionally driven. As shown in FIG. 9A, first, the drive motor of the zoom lens is driven (at time t).₀~ T₃). Next, after the braking period ends (t₃), The drive motor of the focusing lens shown in FIG. 9B is driven (time t).₃'~ T₄').
[0010]
[Problems to be solved by the invention]
In the motor driving method of Patent Document 1 described above, the types of motors that can be used are limited in order to prevent the phases of the pulse signals applied to the driving circuits of the two motors from overlapping each other.
[0011]
For example, as shown in FIGS. 10A and 10B, forward and reverse drive patterns are shown, a two-phase stepping motor widely used in optical equipment is applied. However, in the case of such two-phase excitation driving, it is necessary to always supply a current to the two-phase excitation coil of the motor, so that the time-division driving method cannot be applied.
[0012]
In addition, as shown in FIGS. 11A and 11B, in the case of the 1-2-phase excitation drive of the two-phase stepping motor, since the energization off period of the one-phase coil is used, the above-described time division is used. The driving method is possible.
[0013]
However, in the case of the 1-2-phase excitation drive, the current flowing through the excitation coil is smaller than in the case of the 2-phase excitation. Therefore, there is a possibility that the motor cannot be used at the time of starting which requires a large torque and a large current.
[0014]
Therefore, the present invention has been made in view of the above-described problems, and an optical apparatus that can surely start driving a plurality of motors used for different functions and can shorten the entire driving time. It is an object to provide a motor control device and a control method thereof.
[0015]
[Means for Solving the Problems]
That is, the invention according to claim 1 is a motor control device for an optical device that is provided in an optical device and controls a plurality of motors having at least a first motor and a second motor using a battery as a driving source. Accordingly, the first motor is braked, a regenerative current generated by the braking is returned to the battery, and the drive of the second motor is started during a period in which the regenerative current is returned to the battery. And control means for performing the operation.
[0016]
According to a second aspect of the present invention, in the first aspect, the first motor is a DC motor for driving a zoom lens, and the second motor is an electromagnetic motor for driving a focusing lens. Wherein the stop instruction is a zoom stop instruction.
[0017]
According to a third aspect of the present invention, in the second aspect of the invention, the electromagnetic motor comprises a stepping motor.
[0018]
According to a fourth aspect of the present invention, in the second aspect of the present invention, the electromagnetic motor comprises an ultrasonic motor.
[0019]
According to a fifth aspect of the present invention, a first control means for controlling a first motor using a battery as a driving source, and a second control means for controlling a second motor different from the first motor using the battery as a driving source. The first control means brakes the first motor in response to a stop instruction and outputs a regenerative current generated by the braking to the battery. Wherein the second control means controls the second motor to start using the regenerative current during the braking period of the first motor. And
[0020]
According to a sixth aspect of the present invention, in the fifth aspect of the invention, the first motor is a DC motor for driving a zoom lens, and the second motor is an electromagnetic motor for driving a focusing lens. Wherein the stop instruction is a zoom stop instruction.
[0021]
According to a seventh aspect of the present invention, in the sixth aspect of the invention, the electromagnetic motor comprises a stepping motor.
[0022]
The invention according to claim 8 is the invention according to claim 7, wherein the electromagnetic motor is constituted by an ultrasonic motor.
[0023]
Further, the invention according to claim 9 is a power supply battery, a first motor using the battery as a driving source, a second motor different from the first motor using the battery as a driving source, Instruction means for instructing to start the driving of the second motor while braking the first motor; braking the first motor in accordance with the instruction of the instruction means; and supplying the regenerative current generated by the braking to the power supply. And a control unit that controls the battery to return so as to start driving the second motor during the braking period of the first motor using the regenerative current.
[0024]
According to a tenth aspect of the present invention, in the ninth aspect, the first motor is a DC motor, and the second motor is an electromagnetic motor.
[0025]
An eleventh aspect of the present invention is characterized in that, in the tenth aspect of the present invention, the electromagnetic motor comprises a stepping motor.
[0026]
According to a twelfth aspect of the present invention, in the tenth aspect, the electromagnetic motor comprises an ultrasonic motor.
[0027]
According to a thirteenth aspect of the present invention, there is provided a control method of a motor control device for an optical device which is provided in an optical device and controls a plurality of motors having at least a first motor and a second motor using a battery as a driving source. The first motor is braked according to the instruction, the regenerative current generated by the braking is returned to the battery, and the drive of the second motor is started during a period in which the regenerative current is returned to the battery. It is characterized by the following control.
[0028]
According to the present invention, even if a large torque is required for starting the second motor during the braking period of one DC motor, the DC motor works as a generator, so that the battery capacity is reduced. Since the battery is regenerating electric power instead of being exhausted, the battery plays a role of an auxiliary battery, so that the capacity of the battery is reinforced and the second motor can be reliably started.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0030]
(First Embodiment)
FIG. 1 is a diagram showing a schematic configuration of a camera according to a first embodiment of the present invention.
[0031]
In FIG. 1, a photographing light beam from a subject (not shown) includes a first lens group 11, a second lens group 12, an aperture 13, a shutter 14, a third lens group 15, and a fourth lens group 11, which are fixed to a lens barrel (not shown). The light is guided to a CCD 18 which is an image pickup device via a lens group 16. The image captured by the CCD 18 is converted into an electric signal here and supplied to the microcomputer 22 via the amplifier and A / D converter 19 and the digital signal processing circuit 20.
[0032]
The microcomputer 22 includes a DC motor drive circuit 23 for a DC motor 30, a driver 24 for a stepping motor 34, a driver 25 for an aperture motor 39, a driver 26 for a shutter motor 40, and a zoom switch (SW). ) 42 are connected. A battery 27 for power supply is connected to the DC motor drive circuit 23 and the driver 24, and a battery 28 for power supply is connected to the drivers 25 and 26, respectively. Although the batteries for the DC motor drive circuit 23 and the driver 24 and the batteries for the drivers 25 and 26 are different, they may be the same.
[0033]
The DC motor 30 rotationally drives a lens barrel 32 in a lens barrel (not shown) via an output shaft 31 that is a rotating gear. A cam pin 33 and a cam pin 35 are engaged with the cam grooves formed in the lens barrel 32, respectively. The second lens group 12 and the third lens group 20, a stepping motor 34, and The fourth lens group 16 movably mounted on the ping motor 34 is movably provided. The stepping motor 34 makes the fourth lens group 16 movable via an output shaft 36 as a lead screw and a rack 37 screwed to the lead screw.
[0034]
The luminous flux from a subject (not shown) captured through the first lens group 11, the second lens group 12, the aperture 13, the shutter 14, the third lens group 15, and the fourth lens group 16 is captured on the imaging surface of the CCD 18. It is imaged. Then, the formed image is photoelectrically converted by the CCD 18 and output as an image pickup signal. The imaging signal output from the CCD 18 is amplified to a predetermined level by an amplifier and A / D converter 19 and A / D converted. The A / D-converted digital signal is output to a digital signal processing circuit (a so-called camera signal processing circuit) 20 for digital processing.
[0035]
The CCD 18, the amplifier and the A / D converter 19, the digital signal processing circuit 20, and the like described above have no relation to the content of the present invention, and thus the description thereof is omitted.
[0036]
The microcomputer 22 controls a motor for driving the above-described lens system, and controls drivers 25 and 26 for an aperture motor 39 and a shutter motor 40 for driving the aperture 13 and the shutter 14. The zoom switch 42 is a switch for moving the second lens group 12 and the third lens group 13 in a wide (Wide) direction and a tele (Tele) direction.
[0037]
The second lens group 12 and the third lens group 13 are lens groups for performing magnification (hereinafter, referred to as magnification lenses). Further, the fourth lens group 16 has a compensator function for compensating a displacement of a focal point accompanying movement of the second and third lens groups 12 and 13 for zooming, and a lens group for performing focus adjustment ( Hereinafter, it is referred to as a focusing lens).
[0038]
The DC motor 30 is a motor for driving the lenses 12 and 15 for zooming and the focusing lens 16. The stepping motor 34 is a motor for driving the focusing lens 16.
[0039]
When the DC motor 30 is driven and the output shaft 31 rotates, the lens barrel 32 having a cam groove (not shown) formed on the inner wall rotates, and the cam pins 33 and 35 move in accordance with the locus of the cam groove. For this reason, the zooming lenses 12 and 15 and the focusing lens 16 move in the optical axis direction.
[0040]
Since the load of the DC motor 30 is the largest and the working distance is long, a motor having a large output is used.
[0041]
The output shaft 36 of the stepping motor 34 is a screw that is always screwed with the rack 37 of the focusing lens 16. When the output shaft 36 rotates, the rack 37 moves parallel to the optical axis, and the focusing lens 16 moves in the optical axis direction.
[0042]
The compensator function moves the focusing lens 16 to a focusing position determined by the positions (focal lengths) of the zoom lenses 12 and 15 and the position (subject distance) of the focusing lens 16. Specifically, after the zooming operation following the locus of the cam groove is completed, the focusing lens 16 is controlled to move to a focusing position calculated according to the zooming ratio and the subject distance, so that the in-focus state is obtained immediately after the zooming. Can be realized.
[0043]
The initial positions of the zoom lenses 12, 15 and the focusing lens 16 are determined by a photo interrupter and a sensor (not shown) that detect the initial position of each lens when the power is turned on.
[0044]
Further, the position management of the lens being driven can be determined by counting a drive pulse for driving each lens or a photoreflector (PR) position signal (not shown).
[0045]
FIG. 2 is a diagram showing a circuit configuration of the DC motor drive circuit 23 described above. This DC motor drive circuit 23 can constitute a bridge type chopper circuit.
[0046]
In FIG. 2, switches S1, S2, S3, and S4 composed of transistors are connected in a bridge around a DC motor 30 as shown. A series circuit of switches S1 and S2 and a series circuit of switches S3 and S4 are connected to both ends of the battery 27 in parallel. In addition, return diodes D1, D2, D3, and D4 are connected in parallel to the switches S1, S2, S3, and S4, respectively.
[0047]
The motor drive circuit thus configured can apply both positive and negative voltages and currents to the DC motor 30, and is widely used as a four-quadrant power amplifier capable of driving, regenerating, and rotating in reverse. .
[0048]
3A and 3B illustrate an operation mode when the DC motor rotates in the forward direction in the drive circuit shown in FIG. 2, wherein FIG. 3A illustrates a driving operation of the DC motor, and FIG. 3B illustrates a regenerative operation of the DC motor. FIG. In addition, the element shown by the broken line in the figure indicates that it is not operating.
[0049]
As shown in FIG. 3A, during the driving operation (mode 1), the switches S1 and S4 are turned on, a voltage is applied in the positive direction of the DC motor 30, and the current also flows in the positive direction as shown by the arrow in the figure. To increase. This corresponds to a normal driving operation.
[0050]
On the other hand, as shown in FIG. 3B, the regenerative operation (mode 2) corresponds to the brake mode of the DC motor 30. That is, when all the switches S1 to S4 are turned off during the mode 1 driving, the DC motor 30 is changed to a generator, and generates an electromotive force of the opposite polarity. This is a regeneration mode in which the electromotive force generated through the diodes D2 and D3 is regenerated to the power supply (battery 27).
[0051]
The polarity of the voltage at both ends is inverted by the electromotive force of the DC motor 30. In the mode 2, the voltage at which the electromotive force of the DC motor 30 is generated is obtained, and the battery 27 absorbs the generated power of the DC motor 30.
[0052]
When the DC motor 30 is rotated in the reverse direction, for example, when the zoom direction is opposite to the above-described example, the switches S2 and S3 are turned on during the driving operation, the switches S1 to S4 are turned off during the regenerative operation, and the diode D1 is turned on. And D4 conduct. The other operations are the same as the examples shown in FIGS. 3A and 3B, and the description is omitted.
[0053]
Next, a control operation of the motor according to the first embodiment will be described with reference to a timing chart of FIG. 4 and a flowchart of FIG.
[0054]
First, in step S1, the state of the zoom switch 42 is determined by the user. Here, when the zoom switch 42 is pressed, a drive control signal for the DC motor 30 is output from the microcomputer 22 to the DC motor drive circuit 23 when the magnification is changed in the wide direction or the tele direction. .
[0055]
Accordingly, the process proceeds to step S2, where the switches S1 and S4 are turned on, and a voltage is applied in the positive direction of the DC motor 30. Then, as shown in FIG. 4A, the acceleration period (time t)₀~ T₁), The drive for increasing the rotation speed of the DC motor 30 is performed.
[0056]
Next, in step S3, the DC motor 30 reaches the maximum speed (time t₁), The DC motor 30 rotates at a constant speed (time t).₁~ T₂). This is a constant speed period, which is continued while the zoom switch 42 is pressed by the user in step S4.
[0057]
Then, in step S4, the zoom switch 42 is turned off by the user (time t).₂), And in the subsequent step S5, an off signal is sent from the microcomputer 22 to the switches S1 and S4 in the drive circuit via the control signal. Then, as shown in FIG. 3B, the switches S1 and S4 are turned off. Therefore, a regenerative mode is set in which the electromotive force generated through the diodes D2 and D3 is regenerated to the battery 27. In this case, the DC motor 30 is simultaneously braked.
[0058]
Here, the braking period (time t₂~ T₃), The microcomputer 22 outputs a drive control signal of the stepping motor 34 for the focusing lens 16 to the driver 24. Then, in step S6, as shown in FIG. 4B, the stepping motor 34 for the focusing lens 16 is started in the two-phase excitation mode with the maximum torque (time t).₂').
[0059]
And time t₃Ends the braking period, and the DC motor 30 is stopped, but the stepping motor 34 is driven until the pulse number reaches the predetermined count value in step S7. That is, the timing at which the zoom switch 42 is turned off is the position at which the magnification is instructed, and the position of the focusing lens 16 to be moved is determined accordingly. The number of motor pulses required to move the focusing lens 16 to the determined position is calculated from the count value. Then, the stepping motor 34 is driven by the number of pulses.
[0060]
Thereafter, a time t at which driving is performed for a predetermined number of pulses₅, The driving of the stepping motor 34 is stopped.
[0061]
Time t₃Then, the driving of the DC motor 30 is completed, and the time t₃Time t corresponding to₃', Only the stepping motor 34 for the focusing lens 16 is driven.
[0062]
Incidentally, the entire motor driving time of the DC motor 30 and the stepping motor 34 is the time t.₀~ T₅Period. On the other hand, the driving time of the two conventional motors is the time t since the stepping motor is driven after the DC motor stops.₀~ T₄Met. That is, as shown in FIG. 4B, the driving time of the motor is reduced by Δta as compared with the related art.
[0063]
Conventionally, the stepping motor is operated at time t as shown by the broken line in FIG.₃(Time t₃′), The stop time was at the time t₄Met. However, in the present embodiment, the stepping motor 34 is started immediately after the braking period of the DC motor 30 starts (time t).₂'). Therefore, although the drive time of the stepping motor 34 itself does not change, the stop time is the same as the conventional time t.₄To t₅Move to. This time t₅~ T₄Period Δt of the difference_aHas been shortened.
[0064]
In this way, it is possible to realize a light-weight and small-sized camera that has a faster focusing response than the conventional camera, and does not increase the battery capacity.
[0065]
Note that time t₂~ T₃During the braking period of the DC motor 30, the power of the battery 27 is not consumed by the DC motor 30, but the DC motor 30 functions as a generator to reinforce the battery 27. Therefore, even when the capacity of the battery body is slightly reduced, or when the motor that requires the most battery supply capability is started, the stepping motor 34 for the focusing lens 16 can be reliably started and driven.
[0066]
Further, in the above-described first embodiment, the stepping motor is driven in the two-phase excitation mode. However, the stepping motor is driven in the 1-2-phase excitation mode that can be driven with lower power than the two-phase excitation mode. Of course, it is good.
[0067]
(Second embodiment)
Next, a second embodiment of the present invention will be described.
[0068]
FIG. 6 is a diagram showing a schematic configuration of a camera according to the second embodiment of the present invention.
[0069]
In the above-described first embodiment, an example in which a stepping motor is used as the motor for the focusing lens 16 has been described. In the second embodiment, an ultrasonic motor 45 is used instead of the stepping motor. I have. The driver 44 for the ultrasonic motor 45 is also used as a driver for driving the ultrasonic motor 45. Other configurations and operations are the same as those of the above-described first embodiment. Therefore, the same portions are denoted by the same reference numerals and description thereof will be omitted.
[0070]
The control operation of the motor according to the second embodiment will be described with reference to the timing chart of FIG.
[0071]
When the zoom switch 42 is pressed by the user, the drive control signal of the DC motor 30 for the variable power lens 12 is sent from the microcomputer 22 to the DC motor drive circuit 23 when the magnification is changed in the wide direction or the tele direction. Output to As a result, the switches S1 and S4 are turned on, and a voltage is applied in the positive direction of the DC motor 30. Then, as shown in FIG. 7A, the acceleration period t₀~ T₁In this mode, the rotation speed of the DC motor 30 increases and the motor current also increases in the positive direction, which corresponds to a normal driving operation.
[0072]
Then, the DC motor 30 reaches the maximum speed (time t₁), The DC motor 30 rotates at a constant speed (time t).₁~ T₂). This is a constant speed period. Then, at time t₂When the user turns off the zoom switch, the switches S1 and S4 in the drive circuit are turned off. Therefore, a regenerative mode is set in which the electromotive force generated through the diodes D2 and D3 is regenerated to the battery 27. In this case, the DC motor 30 is simultaneously braked.
[0073]
Here, time t₂At the same time as the braking of the DC motor 30 (time t₂1), the microcomputer 22 outputs a drive control signal of the ultrasonic motor 45 for the focusing lens 16 to the driver 44. Then, as shown in FIG. 7B, the ultrasonic motor 45 for the focusing lens 16 is started. If the moving distance of the focusing lens 16 is short, as shown in FIG.₃At the same time or before the driving of the DC motor 30 is completely stopped, the driving of the ultrasonic motor 45 for the focusing lens 16 is also completed (at time t).₃') Is also possible.
[0074]
In the conventional motor control method, the driving of the DC motor ends (time t₃), The ultrasonic motor is driven (time t₃'). Therefore, as shown by a broken line in FIG.₄Met. However, in the present embodiment, the ultrasonic motor 45 is started immediately after the braking period of the DC motor 30 starts (at time t).₂'), The drive completion time is the time t of the DC motor 30.₃At almost the same time t₃'. Therefore, although the driving time of the ultrasonic motor 45 itself does not change, the time when the driving of the motor is completed is the same as the conventional time t.₄To t_{3 ′}Move to. This time t₃'~ T₄Period Δt of the difference_bHas been shortened.
[0075]
In this way, even with the use of the ultrasonic motor, it is possible to realize a light-weight and small-sized camera that has a faster response than the conventional camera and does not increase the battery capacity.
[0076]
In addition, time t₂~ T₃During the braking period of the DC motor 30, the power of the battery 27 is not consumed by the DC motor 30, but the DC motor 30 functions as a generator to reinforce the battery 27. The ultrasonic motor 45 for the focusing lens 16 can be driven reliably even when the motor slightly needs to be supplied or when the motor that requires the most battery supply capacity is started.
[0077]
Although the ultrasonic motor has a fast response speed, a starting current is required to bring the vibrator into a strong resonance state in order to overcome the static friction force at the time of starting.
[0078]
Note that the above-described embodiment is for describing the present invention, and the present invention is not limited to only the above-described embodiment.
[0079]
For example, in the above-described embodiment, the number of driven motors has been described as two, but the present invention is not limited to this. Since the battery capacity during the regenerative period of the DC motor is reinforced, any number of motors such as an aperture motor for driving the aperture and a shutter motor for driving the shutter may be driven within the range of the battery capacity. Not a problem.
[0080]
In the above-described embodiment, the order in which the motors are driven and controlled is such that the motor for the variable power lens is driven first and the motor for the focusing lens is driven after the motor. There is no problem even if it replaces.
[0081]
Furthermore, in the above-described embodiment, an example is described in which the motor control device of the optical apparatus of the present invention is applied to a camera, but the present invention is not limited to this, and various applications and modifications are possible. Not even.
[0082]
Features of the embodiment
[1] The motor control device of the optical apparatus described in the embodiment includes:
In a motor control device of an optical device that is provided in the optical device and controls a plurality of motors having at least a first and a second motor using a battery as a driving source,
The first motor is braked in response to the stop instruction, the regenerative current generated by the braking is returned to the battery, and the drive of the second motor is started while the regenerative current is flowing back to the battery. Control means for controlling to cause
It is characterized by having.
[0083]
With such a configuration, the regenerative current can be used at the start of driving of the second motor, so that even when the load is large or the remaining battery power is small, it is possible to reliably start the motor.
[0084]
[2] The motor control device of the optical apparatus described in the embodiment includes:
In the motor control device for an optical device according to the above [1], the first motor is a DC motor for driving a zoom lens, the second motor is an electromagnetic motor for driving a focusing lens, The stop instruction is a zoom stop instruction.
[0085]
With such a configuration, focusing is quickly performed after the zoom operation, so that a shutter chance is not missed.
[0086]
[3] The motor control device of the optical apparatus described in the embodiment includes:
In the motor control device for an optical device according to the above [2], the electromagnetic motor is constituted by a stepping motor.
[0087]
With such a configuration, the focusing lens can be quickly driven.
[0088]
[4] The motor control device of the optical apparatus described in the embodiment includes:
In the motor control device for an optical device according to the above [2], the electromagnetic motor is constituted by an ultrasonic motor.
[0089]
With such a configuration, the focusing lens can be quickly driven.
[0090]
[5] The motor control device of the optical apparatus described in the embodiment includes:
An optical system comprising: first control means for controlling a first motor using a battery as a drive source; and second control means for controlling a second motor different from the first motor using the battery as a drive source. In the motor control device of the equipment,
The first control means controls the first motor in response to a stop instruction, and controls the regenerative current generated by the braking to return to the battery.
The second control means controls to start driving the second motor during a braking period of the first motor using the regenerative current.
It is characterized by:
[0091]
With such a configuration, the regenerative current can be used at the start of driving of the second motor, so that even when the load is large or the remaining battery power is small, it is possible to reliably start the motor.
[0092]
[6] The motor control device of the optical apparatus described in the embodiment includes:
In the motor control device for an optical device according to the above [5], the first motor is a DC motor that drives a zoom lens, the second motor is an electromagnetic motor that drives a focusing lens, The stop instruction is a zoom stop instruction.
[0093]
With such a configuration, focusing is quickly performed after the zoom operation, so that a shutter chance is not missed.
[0094]
[7] The motor control device of the optical apparatus described in the embodiment includes:
In the motor control device for an optical device according to the above [6], the electromagnetic motor is constituted by a stepping motor.
[0095]
With such a configuration, the focusing lens can be quickly driven.
[0096]
[8] The motor control device of the optical apparatus described in the embodiment includes:
In the motor control device for an optical device according to the above [7], the electromagnetic motor is constituted by an ultrasonic motor.
[0097]
With such a configuration, the focusing lens can be quickly driven.
[0098]
[9] The motor control device of the optical apparatus described in the embodiment includes:
Power battery and
A first motor driven by the battery,
A second motor different from the first motor using the battery as a drive source;
Instruction means for instructing to start the driving of the second motor while braking the first motor;
The first motor is braked in accordance with an instruction of the instructing means, a regenerative current generated by the braking is returned to the power supply battery, and the regenerative current is used to brake the first motor during a braking period. Control means for controlling to start driving of the second motor;
It is characterized by having.
[0099]
With such a configuration, the regenerative current can be used at the start of driving of the second motor, so that even when the load is large or the remaining battery power is small, it is possible to reliably start the motor.
[0100]
[10] The motor control device of the optical apparatus described in the embodiment includes:
In the motor control device for an optical device according to the above [9], the first motor is a DC motor, and the second motor is an electromagnetic motor.
[0101]
With such a configuration, the second motor can be driven quickly and reliably after the constant speed operation of the first motor.
[0102]
[11] The motor control device of the optical apparatus described in the embodiment includes:
In the motor control device for an optical device according to the above [10], the electromagnetic motor is constituted by a stepping motor.
[0103]
With such a configuration, the second motor can be driven quickly and reliably after the constant speed operation of the first motor.
[0104]
[12] The motor control device of the optical apparatus described in the embodiment includes:
In the motor control device for an optical device according to the above [10], the electromagnetic motor is constituted by an ultrasonic motor.
[0105]
With such a configuration, the second motor can be driven quickly and reliably after the constant speed operation of the first motor.
[0106]
[13] The control method of the motor control device for the optical apparatus described in the embodiment
In a control method of a motor control device of an optical device which is provided in an optical device and controls a plurality of motors having at least a first and a second motor using a battery as a driving source,
The first motor is braked in response to the stop instruction, the regenerative current generated by the braking is returned to the battery, and the drive of the second motor is started during a period in which the regenerative current is returned to the battery. It is characterized in that it is controlled so that
[0107]
With such a configuration, the regenerative current can be used at the start of driving of the second motor, so that even when the load is large or the remaining battery power is small, it is possible to reliably start the motor.
[0108]
【The invention's effect】
As described above, according to the present invention, even if a plurality of motors are started during the regenerative period of the motor, the plurality of motors can be started reliably because the DC motor serves as a generator and reinforces the battery. . In addition, since the driving of the plurality of motors is started earlier, the driving time of the entire motor can be shortened. As a result, the response is faster than that of the conventional camera, and the battery capacity is not increased, the weight is reduced, and It is possible to realize a motor control device and a control method for an optical device that can be downsized.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a camera according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a circuit configuration of a DC motor drive circuit 23.
FIGS. 3A and 3B illustrate an operation mode in a case where the DC motor rotates in the forward direction in the drive circuit shown in FIG. 2; FIG. 3A illustrates a drive operation of the DC motor; FIG. 3B illustrates a regenerative operation of the DC motor; FIG.
FIG. 4 is a timing chart illustrating a control operation of the motor according to the first embodiment.
FIG. 5 is a flowchart illustrating a control operation of the motor according to the first embodiment.
FIG. 6 is a diagram illustrating a schematic configuration of a camera according to a second embodiment of the present invention.
FIG. 7 is a timing chart illustrating a control operation of a motor according to a second embodiment.
FIG. 8 is a diagram showing a typical drive circuit of a conventional DC (direct current) motor.
FIG. 9 is a timing chart illustrating the operation of a conventional motor drive circuit.
FIG. 10 is a waveform diagram of a drive pattern of a two-phase stepping motor in a two-phase excitation mode.
FIG. 11 is a waveform diagram of a drive pattern of a two-phase stepping motor in a 1-2-phase excitation mode.
[Explanation of symbols]
11 first lens group, 12 second lens group (magnifying lens), 13 stop, 14 shutter, 15 third lens group, 16 fourth lens group (focusing lens), 18 CCD 19 ... Amplifier and A / D converter, 20 ... Digital signal processing circuit, 22 ... Microcomputer, 23 ... DC motor drive circuit, 24 ... Driver, 27 ... Battery, 30 ... DC motor, 34 ... Stepping motor, 42. Zoom switch (SW).

Claims (13)

A motor control device for an optical device, which is provided in the optical device and controls a plurality of motors having at least a first and a second motor using a battery as a driving source,
The first motor is braked in response to the stop instruction, the regenerative current generated by the braking is returned to the battery, and the drive of the second motor is started while the regenerative current is flowing back to the battery. Control means for controlling to cause
A motor control device for an optical device, comprising: 2. The apparatus according to claim 1, wherein the first motor is a DC motor for driving a zoom lens, the second motor is an electromagnetic motor for driving a focusing lens, and the stop instruction is a zoom stop instruction. 3. A motor control device for an optical device according to claim 1. 3. The motor control device according to claim 2, wherein the electromagnetic motor includes a stepping motor. The motor control device according to claim 2, wherein the electromagnetic motor is an ultrasonic motor. An optical system comprising: first control means for controlling a first motor using a battery as a drive source; and second control means for controlling a second motor different from the first motor using the battery as a drive source. In the motor control device of the equipment,
The first control unit controls the first motor to brake in response to a stop instruction, and controls a regenerative current generated by the braking to return to the battery,
The second control means controls the start of driving of the second motor during a braking period of the first motor using the regenerative current, so that the motor control device for the optical device is characterized in that . 6. The apparatus according to claim 5, wherein the first motor is a DC motor for driving a zoom lens, the second motor is an electromagnetic motor for driving a focusing lens, and the stop instruction is a zoom stop instruction. 3. A motor control device for an optical device according to claim 1. 7. The motor control device according to claim 6, wherein the electromagnetic motor is a stepping motor. The motor control device for an optical device according to claim 7, wherein the electromagnetic motor is an ultrasonic motor. Power battery and
A first motor driven by the battery,
A second motor different from the first motor using the battery as a drive source;
Instructing means for instructing to brake the first motor and start driving the second motor;
The first motor is braked in accordance with an instruction of the instruction means, a regenerative current generated by the braking is returned to the power supply battery, and the regenerative current is used to brake the first motor during a braking period. Control means for controlling to start driving of the second motor;
A motor control device for an optical device, comprising: The motor control device according to claim 9, wherein the first motor is a DC motor, and the second motor is an electromagnetic motor. The motor control device for an optical device according to claim 10, wherein the electromagnetic motor is configured by a stepping motor. 11. The motor control device for an optical device according to claim 10, wherein the electromagnetic motor comprises an ultrasonic motor. In a control method of a motor control device of an optical device that is provided in an optical device and controls a plurality of motors having at least a first and a second motor using a battery as a driving source,
The first motor is braked in response to the stop instruction, the regenerative current generated by the braking is returned to the battery, and the drive of the second motor is started while the regenerative current is flowing back to the battery. A method for controlling a motor control device of an optical device, characterized by controlling the motor control device to perform control.

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