JP2019020642A - Driving control device, optical device, and imaging device - Google Patents

Abstract

To provide a lens device for securing power necessary during acceleration/deceleration, and for obtaining acceleration/deceleration performance capable of maintaining operability intended by an operator even when a power source having a small power source capacity is connected.SOLUTION: A lens driving control device comprises: a driving circuit for driving a motor which drives a movable optical element by power supply; a power storage part connected in parallel with the driving circuit; a first switch for separating the power storage part from the driving circuit; a second switch arranged between the driving circuit and the power storage part for separating the driving circuit from a power source; a control part for controlling opening/closing of the first switch and the second switch; and a mode setting part for setting a charging priority mode for giving priority to charging to the power storage part and a driving priority mode for giving priority to driving of the driving circuit at least during the opening/closing of the first switch and the second switch by the control part. The control part controls the opening/closing of the first switch and the second switch on the basis of at least a charging state of the power storage part and the mode set by the mode setting part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drive control device, an optical device, and an imaging device that control driving of a movable optical element.

  Conventionally, in a lens apparatus, a technique for driving movable parts such as zoom, focus, iris, and extender with a motor is disclosed in Patent Document 1. Patent Document 2 is configured such that an additional amount proportional to the amount of change in the unit time of the command signal is added to the command signal and input to the control means, and the proportionality factor related to the proportional is the command signal A lens operating device that is configured to be inversely proportional to the size to improve followability is disclosed.

Japanese Patent Laid-Open No. 5-127061 Japanese Patent No. 4865398

  However, in the techniques of Patent Documents 1 and 2, if the power supply capacity is not large, the power required for acceleration / deceleration cannot be sufficiently supplied to the lens device, and the operation of the movable part is more than the operation intended by the operator. This may cause a problem that the operability is not good for the operator. On the other hand, in order to always be able to supply the electric power necessary for acceleration / deceleration, the power supply can be increased in size. Further, if the acceleration / deceleration performance becomes too high, the operation becomes more responsive than the operator intends, and conversely, the operator may be difficult to operate.

  Accordingly, an object of the present invention is to provide a drive control device that is advantageous in achieving both the operability of driving an optical element and a small required power capacity.

  In order to achieve the above object, a lens drive control device according to the present invention includes a drive circuit that drives a motor that drives a movable optical element of a lens device by supplying power from a power supply, and a power storage unit connected in parallel with the drive circuit. A first switch for disconnecting the power storage unit from the drive circuit, a second switch disposed between the drive circuit and the power storage unit, and disconnecting the drive circuit from the power source, A control unit that controls opening and closing of the first switch and the second switch, and charging priority that prioritizes charging of the power storage unit in at least opening and closing of the first switch and the second switch by the control unit A mode setting unit that sets a mode and a drive priority mode that prioritizes driving of the drive circuit, and the control unit includes at least a charging state of the power storage unit, and the mode setting unit. Based on the set mode, controls the opening and closing of the second switch and the first switch, the lens drive control device, characterized in that.

  According to the present invention, for example, it is possible to provide a drive control device that is advantageous in achieving both the operability of driving an optical element and a small required power capacity.

2 is a drive circuit of the lens drive control device according to the first exemplary embodiment. FIG. 6 is a diagram illustrating a switch operation of a drive circuit of the lens drive control device according to the first exemplary embodiment. 3 is a current waveform of the lens drive control device of Example 1. FIG. 3 is a current waveform of the lens drive control device of Example 1. FIG. 6 is a block diagram of a control signal control device of a lens drive control device of Embodiment 2. FIG. It is a figure explaining the coefficient of the lens drive control apparatus of Example 2. FIG. It is a figure explaining pushing-pull operation of the lens drive control apparatus of Example 3. FIG. It is a figure explaining pushing-pull operation of the lens drive control apparatus of Example 3. FIG. FIG. 10 is a diagram illustrating a demand operation of the lens drive control device according to the third embodiment.

  The present invention will be described in detail based on the embodiments shown in the drawings.

The lens drive control device of the present embodiment will be described with reference to FIGS.
FIG. 1 is a drive circuit diagram mounted on the lens drive control device of the present embodiment. Mainly, a transistor bridge (hereinafter also referred to as a Tr bridge or a drive circuit) and a capacitor (power storage unit) connected in parallel with the transistor bridge. ) C. The DC power supply E is a DC power supply that supplies power to the drive circuit, and corresponds to a camera device to which the lens device is connected, an external power supply device, and the like. A current limiting unit Lim is provided in series with the power source, a switch (first switch) SW1 is provided in series with the capacitor C, and a switch (second switch) SW2 is provided in series with the drive circuit. The lens drive control device 1 further includes a switch control unit 2 that controls opening and closing of the switches SW1 and SW2. Further, an assist setting unit 4 that switches between enabling / disabling of the assist function by the capacitor C, a mode setting unit 5 that selectively sets the control mode of the switch control unit 2, and a control signal generation that controls the switching operation of each transistor of the Tr bridge Part 3. The control signal generator 3 (control signal generator) 3 receives a command signal from the command signal input unit 6 and a feedback signal such as the position of the movable optical member 8 from the detection unit 7 described later. The movable optical member (movable optical element) 8 (zoom lens, focus lens, diaphragm, extender, filter, etc.) of the lens device (optical device) is driven by driving the motor. The position of the movable optical member 8 is detected by the detection unit 7.

The current limiting unit Lim is a circuit for limiting the current supplied from the power source E to the drive circuit, and is configured by, for example, a transistor and a resistor arranged in series between the power source E and the drive circuit. The current flowing through the transistor is detected by this resistor to determine the base potential of the transistor, thereby limiting the current value of the transistor.
Capacitor C has a capacity capable of sufficiently supplying electric power necessary for acceleration / deceleration of the motor.

The switch SW1 is a switch for connecting / disconnecting the capacitor inserted in parallel to the Tr bridge to / from the drive circuit, and the switch SW2 is a switch for connecting / disconnecting the power source E and the Tr bridge.
The Tr bridge is a transistor bridge for driving a motor that is composed of four publicly known transistors.
The diode D is a power supply protection diode for preventing a current from flowing from the capacitor C having a sufficient capacity to the power supply E.
With the above configuration, by controlling the Tr bridge, power from the power source E is supplied to the motor to control the motor.

Hereinafter, the operation details of the switch SW1 and the switch SW2, which are essential elements of the present invention, will be described with reference to FIG.
FIG. 2 is a table summarizing whether the switches SW1 and SW2 are open and shorted and the Tr bridge control is valid and invalid in each state.

First, the function of connecting the capacitor C to the drive circuit is referred to as an assist function. Hereinafter, the case where the assist function is valid and the case where the assist function is invalid will be described separately. The assist function can be enabled / disabled by a lens device or a switch (assist setting unit 4) of an operation device of the lens device.
The case where the assist function is effective, the capacity of the power source E is small, and the charging state of the capacitor is insufficiently charged below a predetermined value (states 1 to 3 in FIG. 2) will be described.

  Conditions 1, 2, and 3 correspond to the switch operation mode of charge priority mode 1, charge priority mode 2, and drive priority mode. In the charge priority mode 1 (state 1 in FIG. 2), the switch SW1 is short-circuited and the switch SW2 is opened, and all the power from the power source E is supplied to the capacitor for charging. As a result, the capacitor can be charged in the shortest time, but since the power cannot be supplied to the Tr bridge, the motor cannot be driven.

  Next, in the charge priority mode 2 (state 2 in FIG. 2), the switches SW1 and SW2 are short-circuited, and the power from the power source E is supplied to both the capacitor charging and the Tr bridge. In this mode, the minimum power is supplied to the motor by controlling the Tr bridge. The capacitor is charged simultaneously with the power supply to the motor. Therefore, this minimum power supply is, for example, sufficient power to hold the position of the optical element connected to the tip of the motor, but the capacitor C is not sufficiently charged. This is a power supply that may not be driven with a desired response when driving an optical element.

  Further, in the drive priority mode (state 3 in FIG. 2), the switch SW1 is opened and the switch SW2 is short-circuited, and all the power from the power source E is supplied to the Tr bridge. As a result, although the assist from the capacitor cannot be obtained, the optical element can be driven by controlling the motor. However, since the power supply capacity is small, a desired response can be obtained depending on the driving conditions such as acceleration / deceleration of the optical element. In this case, the electric power may not be able to be driven. Drive priority mode gives priority to motor driving with acceleration / deceleration when the motor is driven immediately after the power is turned on and the capacitor is insufficiently charged, or when the amount of charging of the capacitor is insufficient due to continued motor driving with acceleration / deceleration This mode is set when necessary.

  Next, the case where the assist function is effective, the capacity of the power source E is small, and the capacitor is fully charged (when the charge amount is greater than or equal to a predetermined amount) (state 4 in FIG. 2) will be described. Under this condition, the switch SW1 and the switch SW2 are short-circuited, and the power from the power source E is supplied to the capacitor and the Tr bridge. Here, since the capacity of the capacitor is sufficiently large, a temporary large current required for accelerating and decelerating the motor can be supplied from the capacitor, and at the same time, other than this temporary large current is supplied from the power source E. .

  Here, the current waveform supplied to the Tr bridge when there is no supply from the capacitor C will be described. FIG. 3 shows a current waveform supplied to the Tr bridge when there is no supply from the capacitor C. The power supply E is supplied between t1 and t2 in the acceleration state of the motor and between t3 and t4 in the deceleration state. A current limited by a current limit threshold that protects the power supply E provided flows. FIG. 4 shows a current waveform supplied to the Tr bridge when there is supply from the capacitor C. By supplying from the capacitor C from t1 to t2 in the motor acceleration state and from t3 to t4 in the deceleration state, a current exceeding the current limit threshold can be supplied to the Tr bridge.

  Next, a case where the assist function is valid and the capacity of the power source E is large (state 5 in FIG. 2) will be described. When the capacity of the power source E is large, it is considered that the current that can be supplied to the Tr bridge is not in a state where the current is insufficient under normal use conditions for driving the movable optical member. . However, if the current supplied to the Tr bridge is greater than or equal to a predetermined value and continues for a certain period of time and the rotation of the motor cannot be confirmed, it may be in a state where it cannot operate due to a drive system abnormality or the like. . In such a case, in order to avoid supplying an excessive current and damaging the device, the capacitor C is disconnected from the circuit by opening the switch SW1 and shorting the switch SW2. Only power from the power source E is supplied to the Tr bridge. Thereby, the current from the capacitor C is not supplied, and the supply of current more than necessary is stopped. In this embodiment, the current of a predetermined value is set to a current limit value and the predetermined time is set to 3 seconds to prevent excessive current from flowing and protect the apparatus. In addition, as described in the case of the state 5 described here, the switch SW1 is opened when the motor has not been rotated for a predetermined time or more due to a drive system abnormality or the like. The same applies to the cases of states 1, 2, and 4.

  Finally, when the assist function is disabled (state 6 in FIG. 2), the switch SW1 is opened and the switch SW2 is short-circuited, and only power from the power source E is supplied to the Tr bridge.

  In the above description, the case where the charge amount of the capacitor is insufficiently charged below a predetermined value indicates, for example, a state of less than 80% of the state of the full charge amount. That is, the charge completion condition refers to a state of 80% or more of the state of the fully charged charge amount. In addition, it can be set fluidly based on the drive load (power consumption) of the drive target, the environmental temperature, the capacity of the power supply being fed, and the frequency of acceleration / deceleration drive based on the drive history of the drive target. Also good.

  According to the lens drive control device according to the present embodiment, by controlling the switches SW1 and SW2 in this way, even when a power supply with a small power supply capacity is connected, power required for acceleration / deceleration is ensured, and the operator's Acceleration / deceleration that can maintain the intended operability can be obtained.

The lens drive control device of this embodiment will be described with reference to FIGS.
This embodiment combines the control of the control signal generation device that controls the Tr bridge of the lens device 1 shown in FIG. 1 to ensure the necessary power during acceleration / deceleration even when a power source with a small power source capacity is connected. It aims to obtain acceleration / deceleration that can maintain the operability intended by the user.
FIG. 5 shows a block diagram of the control signal generator 3 of this embodiment.

  The control signal generation unit 3 includes a difference calculation unit 55, an addition unit 51, a control unit 52, a coefficient determination unit 56, and a parameter determination unit 57. The difference calculating means 55 receives a command signal Vn for driving a lens device to be driven from a controller (not shown), and calculates a difference from the command signal Vn-1 at the previous time in time series. To do. That is, the change amount of the command signal per unit time is calculated. Then, a difference calculation signal Rn (= β × (Vn−Vn−1)) obtained by multiplying the difference calculation result (Vn−Vn−1) by a coefficient β inversely proportional to the command signal Vn is output to the adding means 51. The coefficient β is derived by β = k1 / Vn + k2 in the coefficient determining means 56 based on the command signal Vn. The constants k1 and k2 here are determined by the parameter determination means 57 based on the command signal Vn.

  With this configuration, the difference calculation signal Rn based on the command signal Vn is added to the command signal Vn by the adding means 51, and the control means 52 detects the addition result (Vn + Rn) and the position of the movable optical member 54 from the detection unit 7. Based on the information (position information or speed information), the drive signal Sc is output to the drive means 53. Thereby, driving of the movable optical member 54 such as a zoom lens, a focus lens, an iris, an extender, and a filter to be controlled is controlled. Therefore, when the command signal Vn changes steeply, the difference calculation signal Rn increases, so that the control unit 13 can control the drive unit 14 by reflecting the steepness in the command signal Vn.

  Feedback control is performed by feeding back to the control means 13 a position signal Sf that is an output of a sensor that detects the current position of the movable optical member 54 in the movable range. When performing this feedback control, the signal for detecting the state of the movable optical member is not limited to the position signal, and a necessary signal may be appropriately detected according to the control method or the like to perform the feedback control.

  Switching of the Tr bridge circuit of the lens drive control device 1 of FIG. 1 is controlled based on the drive signal Sc generated by the control signal generator 3 shown in FIG. 5 reflecting the sensitivity of the change in the command signal Vn. . Further, similarly to the first embodiment, the switches SW1 and SW2 are controlled to effectively use the capacitor C, and even when the power supply capacity is small, necessary power is ensured at the time of acceleration / deceleration, and sufficient followability to the command signal is achieved. A drive control device that can ensure the above is realized.

  When the lens drive control device 1 in FIG. 1 is combined with the followability improving technology of the control signal generation unit 3 in FIG. 5, the drive control of the movable optical member is performed only by the lens drive control device 1 in the first embodiment. Followability is improved. However, at the actual shooting site, when the followability of the actual drive of the driven part with respect to the operation of the operator is better than the followability assumed by the operator of the lens apparatus, the operator may feel difficult to operate. Or, the operation may be uncomfortable. For this reason, it is an important viewpoint for the operator to provide a lens device with better operability so that the operator of the lens device has a followability that does not cause a sense of incongruity. In particular, there is a strong tendency that the stopping performance, which is the performance when stopping the movable optical member, is controlled with better followability to the sense of the operator. Therefore, in this embodiment, the tracking performance with respect to the command signal is eased by correcting the coefficient β used for the calculation of the difference calculation signal Rn shown in FIG. 5, that is, k1 and k2.

  In the configuration of the present embodiment, as means for reducing the follow-up performance, stopping the replenishment of the shortage when the power supply capacity for acceleration / deceleration by opening the switch SW1 is small, and the difference in the control signal generator 3 The coefficient β used for the calculation of the calculation signal Rn may be reduced. Since the switch SW1 is configured by hardware, it is often difficult to quickly open and close the switch SW1 when repeatedly driving the movable optical member with acceleration / deceleration.

  Therefore, in this embodiment, when the switch SW1 and the switch SW2 are in a short-circuited state, that is, in a state in which a temporary large current can be supplied when the switch starts and stops, the coefficient β (constant k1) is based on the operating state of the movable optical member. And k2) are appropriately changed.

FIG. 6 is a table explaining the relationship between the driving state of the switch or motor and the coefficient β (constants k1 and k2).
When the motor starts moving (when changing from the stopped state to the driving state), the set value of the coefficient β (constant k1 or k2) is applied as it is. On the other hand, when stopping (when changing from the driving state to the stopping state), a value obtained by multiplying the set value of the coefficient β (constant k1 or k2) by a predetermined coefficient less than 1 is applied. The predetermined coefficient is approximately 0.5 or more and less than 1.0.

  According to the lens drive control device according to the present embodiment, it is possible to control the switches SW1 and SW2 configured as described above, and to further improve the followability by the control signal generation device. Further, even when a power source having a small power source capacity is connected, there is an effect that it is possible to secure power necessary for acceleration / deceleration and to obtain acceleration / deceleration that can maintain the operability intended by the operator.

The lens drive control device of this embodiment will be described with reference to FIGS.
In this embodiment, a problem that occurs in lens drive control due to a difference in the operation mode of the lens apparatus is solved. One operation mode of the broadcast lens apparatus is a push-pull operation method. The push / pull operation rod used in this push / pull operation is shown in FIGS. FIG. 7 shows a photographing apparatus having a push-pull operation rod 74. The lens apparatus 71, a camera apparatus 72 that is connected to the lens apparatus 71 and photographs a subject image formed by the lens apparatus, and an image that the operator 76 is photographing. Is provided with a viewfinder 73 for visually recognizing. The push / pull operation rod 74 is operated by the operator 76 to push and pull in the optical axis direction of the lens device, thereby operating the zoom position of the lens device 71 and rotating around the axial direction of the push / pull operation rod 74. Thus, the focus position can be operated. The push / pull operation rod 74 includes a push / pull operation rod detection unit 75 fixed to the photographing apparatus, and the push / pull operation rod 74 is positioned around the optical axis direction of the push / pull operation rod 74 and the optical axis of the push / pull operation rod 74. Rotation to detect. Based on the detected position and rotation amount in the optical axis direction, the zoom position and the focus position can be operated only by operating the push-pull operation rod 74. As described above, the push / pull operation rod 74 is an operation mode in which the focal length of the zoom is determined by performing a push / pull operation in the optical axis direction of the lens device 71.

  Compared with the zoom operation by the zoom demand shown in FIG. 9, the zoom operation on the push-pull operation rod 74 has a feature that the operator can operate intuitively. In the operation of the zoom demand 77, the zoom speed is operated, whereas in the push-pull operation, the zoom position is operated. The operation of the zoom demand 77 shown in FIG. 9 includes a ring-type zoom operation unit that is a type of demand that is held by the operator 76 with the left hand. In demand operation, when accelerating, the operator's finger from the origin position pushes down (rotates) the operating part such as the operating ring around the axis against the elastic force of a spring, etc. The operation of returning to the origin position while restraining the rotation by using the restoring force while resisting the above is performed. Thus, with the push / pull operation rod 74, in the operation in the zoom operation direction, the zoom operation to the telephoto side and the wide angle side can be operated by applying the same force to the operation direction, and the position is directly operated. Therefore, it can be operated more intuitively than the demand operation.

  Therefore, the zoom position overshoot is less likely to occur when the push-pull operation rod 74 is operated than when the demand operation is performed.

  Therefore, in this embodiment, the switch SW1 and the switch SW2 are short-circuited with respect to the zoom operation by the push-pull operation with respect to the lens control device having the lens drive control device 1 in FIG. 1 and the control signal generation unit 3 in FIG. Maintain state. The coefficients β (constants k1 and k2) used in the control signal generator 3 are not changed at the time of stopping as in the second embodiment, and are always set to the set values. That is, it is set so that the followability of the movable optical member with respect to the command signal is maximized.

  According to the lens drive control device according to the present embodiment, it is possible to control the switches SW1 and SW2 configured as described above, and to further improve the followability by the control signal generation device. In addition, even if a power source having a small power capacity is connected, there is an effect that it is possible to secure an electric power necessary for acceleration / deceleration and to obtain acceleration / deceleration that can maintain the operability intended by the operator.

An imaging apparatus having a lens apparatus (optical apparatus) having a drive control device that controls driving of the movable optical element described in the illustrated embodiment, and an imaging element that receives an image formed by the lens apparatus is configured. Thus, an imaging apparatus that can enjoy the effects of the present invention can be configured.
As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

1: Drive control device 2: Switch control unit 5: Mode setting unit 8: Movable optical element 71: Lens device E: Power source C: Power storage unit SW1: First switch SW2: Second switch

Claims (10)

A drive control device for controlling the drive of a movable optical element,
A drive circuit that drives a drive unit that drives the optical element by supplying power from a power source;
A power storage unit connected in parallel with the drive unit;
A first switch for disconnecting the power storage unit from the drive circuit;
A second switch for disconnecting the drive circuit from the power source;
A control unit that controls opening and closing of the first switch and the second switch;
A charge priority mode that prioritizes charging of the power storage unit, and a setting unit that selectively sets a drive priority mode that prioritizes driving of the drive unit,
The drive control device, wherein the control unit controls opening and closing of the first switch and the second switch based on a mode set by the setting unit.   2. The drive control device according to claim 1, wherein the control unit closes the first switch and the second switch when a state of charge of the power storage unit satisfies a completion condition.   3. The drive control device according to claim 1, wherein the control unit closes the first switch in the charge priority mode when a state of charge of the power storage unit does not satisfy a completion condition. .   The drive control device according to claim 3, wherein the control unit opens or closes the second switch based on a state of charge of the power storage unit.   2. The control unit according to claim 1, wherein when the state of charge of the power storage unit does not satisfy a completion condition, the control unit opens the first switch and closes the second switch in the drive priority mode. 4. The drive control device according to claim 1. A control signal generator for generating a control signal for controlling the drive circuit based on a command signal;
The control signal generation unit generates the control signal by adding a value obtained by multiplying a change amount per unit time of the command signal by a coefficient to the command signal. The drive control apparatus according to any one of the above.   The drive control device according to claim 6, wherein when the first switch and the second switch are closed, the value of the coefficient is changed based on an operation state of the optical element. An operation unit including a push-pull operation rod for generating the command signal;
The control signal generation unit multiplies the value of the coefficient by a value not less than 0.5 and less than 1.0 when the operation state of the optical element is changed from the drive state to the stop state by the operation unit. The drive control device according to claim 7, wherein the value is changed.   9. An optical apparatus comprising: the drive control device according to claim 1; and an optical element whose drive is controlled by the drive control device.   An image pickup apparatus comprising: the optical apparatus according to claim 9; and an image pickup element that receives an image formed by the optical apparatus.

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