JP6781592B2 - Lens device and imaging device with it - Google Patents

Description

The present invention relates to a lens device, and more particularly to speed control of driving the lens device.

Conventionally, a lens device that can be attached to and detached from a camera or the like is controlled by a power supply (external power supply) supplied from an external device such as a camera. Further, the lens device has movable optical members such as an iris, a zoom, and a focus, and the speed of the movable optical member is controlled so that the movable optical member can be driven at a constant speed. Further, there are some that use the power supply supplied from the external device as a power source (drive power source) for driving the movable optical member as it is. Therefore, the drive power supply may fluctuate depending on the external device, and when the voltage of the external power supply becomes lower than the desired voltage, the drive speed of the movable optical member becomes slower, so that the drive power supply becomes slower than the predetermined voltage. A technique for stopping is also disclosed (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 7-281243

A method in which a movable optical member can be driven even if the driving speed is slower than when the driving is stopped when the voltage of the driving power source becomes lower than the desired voltage as in the prior art disclosed in the above-mentioned patent document. However, it is easy for users to use. However, in this case, since the drive voltage is insufficient, the vehicle cannot be driven at a constant speed even if the speed is controlled. Furthermore, even if the power supply voltage does not fluctuate, if the drive load increases due to changes in the ambient temperature, etc., a larger drive voltage is required to drive at the same speed as before the increase in the drive load. The drive voltage may be insufficient. As described above, when the drive voltage is insufficient, it is not possible to drive at a constant speed even if the speed is controlled, and the image becomes unsuitable especially in moving image shooting.
An object of the present invention is to provide a lens apparatus and an imaging apparatus including the same allowed the drive control of the movable optical member at a stable speed.

To achieve the above object, a lens device of the present invention, in the lens device to have a driving means for driving the movable optical member and the movable optical member, wherein the movable optical member by said driving means in the supplied power supply voltage speed of the movable optical member in the case of driving the drive current of said drive means, based on at least one of the driving voltage of said driving means, and setting means for setting a maximum speed of said movable optical member, wherein the maximum speed It is characterized by having a control means for controlling the speed of the movable optical member by the drive means with the upper limit speed.

According to the present invention, it is possible to provide a lens apparatus and an imaging apparatus including the same allowed the drive control of the movable optical member at a stable speed.

The block diagram which shows the structure of the lens apparatus in Example 1. FIG. The graph which shows the relationship between the drive voltage and time, and the drive speed and time in Example 1. The flowchart which showed the flow of changing the setting value of the maximum speed in Example 1. A table showing the relationship between the power supply voltage and the maximum speed in the first embodiment. The flowchart which showed the flow of changing the setting value of the maximum speed in Example 2. The block diagram which shows the structure of the lens apparatus in Example 3. FIG. The graph which showed the relationship between the drive speed and the drive current in Example 3. The flowchart which showed the flow of changing the setting value of the maximum speed in Example 3.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, the lens apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 shows the configuration of the lens device according to the first embodiment of the present invention.

The lens device 100 has a structure that can be attached to and detached from the camera device 200, and when attached to the camera device 200, power system power supply and signal system power supply are supplied from the camera device 200, and a communication line is connected. The lens device 100 includes a zoom lens 110 (movable optical member), a CPU 120, an operation unit 130, a position detection unit 140, a drive unit 150, a DC motor 160 (drive means), a storage unit (storage means) 170, as shown in FIG. It is composed of a voltage detecting unit 180 (voltage detecting means). In addition, movable optical members such as a focus lens and an iris (not shown) are also configured, but are omitted for the sake of simplicity.

Hereinafter, the zoom lens 110, which is one of the movable optical members, will be described as an object of the present invention, but the present invention can be similarly applied to other movable optical members such as a focus lens and an iris. Please note.

Hereinafter, each component will be described.
The operation unit 130 is operated by the user and outputs a signal corresponding to the operation amount. The CPU 120 detects a signal from the operation unit 130 and calculates a speed command value. The speed command value is a command value for commanding driving at the maximum speed when the operation unit 130 has the maximum operation amount. However, the maximum speed shall be controlled within the limit set up to the maximum speed. The position detection unit 140 detects the position of the zoom lens 110. The CPU (control means, speed detection means) 120 calculates the speed (lens speed) of the zoom lens 110 from the position detected by the position detection unit 140, and sends a drive signal so that the lens speed becomes the speed of the speed command value. It is generated (speed control) and output to the drive unit 150. The drive unit 150 drives the zoom lens 110 by applying a voltage corresponding to the drive signal to the DC motor 160 based on the power system power supply supplied from the camera device 200. The initial value of the set value of the maximum speed is stored in advance in the storage unit 170. The voltage detection unit (setting means) 180 detects the voltage value of the power system power supply, and changes (sets) the setting value of the maximum speed of the zoom lens 110 according to the voltage value.
The method of changing the maximum speed setting value will be described later.

Next, the relationship between the power system power supply and the drive speed in this embodiment will be described.
FIG. 2 shows the relationship between the drive voltage and time, and the drive speed and time in this embodiment. The graph of FIG. 2 is a graph when the zoom lens 110 is driven by giving a maximum speed set from the wide-angle end to the telephoto end as a command value. The relationship between drive voltage and time is shown in (a-1), (b-1), and (c-1), and the drive speed and time are shown in (a-2), (b-2), and (c-2). Shows the relationship. The driving speed here is the driving speed of the zoom lens 110 during the period excluding the acceleration at the start of movement and the deceleration before stopping. First, (a-1) and (a-2) are graphs of an example in which the supply voltage of the power system power supply is 12 V and the maximum speed setting value is set to 30 rpm (rotation per minute) as the initial value. .. The CPU 120 controls the speed so that the speed of the zoom lens 110 becomes constant during driving. Therefore, (a-1) shows how the drive voltage is adjusted so that the drive speed does not fluctuate according to the drive load of the zoom lens 110. Further, (a-2) indicates the driving speed at the time of (a-1), and the driving speed of 30 rpm, which is the maximum speed set by adjusting the driving speed (speed control), is performed. It can be driven at a constant speed. In this case, since the entire movable range can be driven at a constant speed, the maximum value of the drive voltage shown in (a-1) and the voltage of the power system power supply (12 V in (a-1)) are used. It is also possible to set a higher maximum speed that can drive the entire movable range at a constant speed based on the difference between the two.

Next, (b-1) and (b-2) are graphs when the power supply of the power system becomes 10 V while the maximum speed setting is 30 rpm, which is the initial value. In the lens device of the present invention, the maximum voltage that can be applied to the DC motor 160 that is the driving means depends on the voltage of the power system power supply, which is the power supply voltage. (B-1) shows a case where the drive voltage of 10 V or more cannot be applied to the DC motor 160 because the voltage of the power system power supply is 10 V. Therefore, the drive voltage is limited to 10V. In that case, as shown in (b-2), the drive speed is lower than 30 rpm and the speed control cannot be applied, so that the drive speed fluctuates with the drive load. In other words, (b-2) is a graph showing the driving speed under the condition that the driving voltage of the DC motor 160 is constant. In a lens device that uses the power system power supply as it is, the drive speed becomes slower when the power system power supply becomes low, and further, the drive speed fluctuates. Such speed fluctuations make the image difficult to see, especially in moving image shooting, and significantly deteriorate the usability of the user.

Examples of applying the present invention are shown in (c-1) and (c-2). (C-1) and (c-2) are graphs showing an example of changing the setting of the maximum speed from the initial value of 30 rpm to 20 rpm when the supply voltage of the power system power supply becomes 10 V. In the present invention, since the set value of the maximum speed is changed according to the supply voltage of the power system power supply by the method described later, the drive voltage is not limited. In (c-1), it is shown that the speed control can be applied at the set maximum speed even when the power system power supply is 10V. Therefore, as shown in (c-2), the drive speed can be driven at a constant speed of 20 rpm.

Next, a method of changing the maximum speed setting value will be described.
FIG. 3 is a flowchart showing the flow of changing the set value of the maximum speed of this embodiment.

First, when the power is turned on to the CPU 120, the process proceeds to step S11. In step S11, the voltage detection unit 180 detects the voltage of the power system power supply. Next, the process proceeds to step S12. In step S12, the maximum speed corresponding to the voltage detected in step S11 is obtained from the data (voltage speed information) showing the relationship between the power system power supply voltage and the maximum speed stored in advance in the storage unit 170. FIG. 4 is an example of voltage / velocity information, and the maximum speed at which the speed can be controlled is associated with the voltage of the power system power supply and stored in the storage unit 170.

In step S12, the maximum speed corresponding to the voltage value in the correspondence table closest to the detected voltage of the power system power supply is obtained as the set value. Next, in step S13, the setting value of the maximum speed of the zoom lens 110 is changed to the maximum speed obtained in step S12. Next, in step S14, the voltage of the power system power supply is detected in the same manner as in step S11. In step S15, it is determined whether or not the voltage detected in step S14 has changed from the voltage detected last time. If it has not changed, the process returns to step S14, and steps S14 and S15 are repeated at regular intervals. If the voltage changes in step S15, the process returns to step S12, and the change of the maximum speed set value is repeated.

As described above, even if the power system power supply voltage fluctuates, the setting value of the maximum speed is changed accordingly so that the speed control can be applied, so that it is always possible to drive at a constant speed.

Further, in this embodiment, the power source of the lens device 100 has been described as being supplied from the camera device 200, but the present invention is not limited to this, and even if the lens device 100 is configured with a power supply unit such as a battery. Naturally good.

Further, in this embodiment, an example in which the maximum speed setting value is always changed by the power system power supply voltage has been described, but the present invention is not limited to this. For example, it may be executed only when the power is turned on. Further, it may be executed only when the power system power supply voltage is equal to or less than a predetermined predetermined voltage value, and when it is equal to or more than a predetermined value, it may be set to the maximum speed setting value of the initial value.

Further, in this embodiment, as an example of voltage / velocity information, an example of obtaining the maximum speed from the correspondence table between the power system power supply voltage and the maximum speed has been described, but the present invention is not limited to this. The calculation formula may be held and the maximum speed may be obtained from the calculation formula.

Hereinafter, the lens apparatus according to the second embodiment of the present invention will be described with reference to FIG. In the first embodiment, an example of obtaining the maximum speed by using the voltage / velocity information stored in advance has been described, but in this embodiment, an example of setting the maximum speed from the lens speed at the time of actual driving will be described.
Since the configuration of the lens device according to this embodiment is the same as that of the first embodiment, the description thereof will be omitted.

FIG. 5 is a flowchart showing the flow of setting the maximum speed of this embodiment.
First, when the power is turned on to the CPU 120, the process proceeds to step S21. In step S21, the zoom lens 110 is driven from the wide-angle end to the telephoto end in a state where the maximum speed of the initial value stored in advance is set. Next, the process proceeds to step S22. In step S22, the minimum lens speed when driven in step S21 is calculated. The lens speed here is the speed of the zoom lens 110 in a period excluding the acceleration at the start of movement and the deceleration at the stop, and the slowest speed within that period is obtained. As an exclusion method at the time of acceleration and deceleration, a period for driving a certain amount of movable area from the wide-angle end and the telephoto end may be excluded, or a certain time from the start of movement and a certain time until stop may be excluded. And so on. Next, in step S23, it is determined whether or not the drive in step S21 can be driven at a constant speed of the maximum speed. In other words, it is determined whether or not the minimum speed obtained in step S22 is within the tolerance of the maximum speed (range of speed variation controllable by speed control) of the maximum speed commanded in step S21. If it is determined that the vehicle cannot be driven at the maximum speed, the process proceeds to step S24, and if it is determined that the vehicle can be driven at the maximum speed, the process ends. In step S24, the set value of the maximum speed is changed to a speed equal to or lower than the minimum speed. Here, the minimum speed obtained in step S22 may be set as the maximum speed to be newly set, or may be set to a speed slower by a predetermined amount from the minimum speed measured in consideration of the margin. For example, when the initial value setting maximum speed is 30 rpm and the tolerance is ± 2 rpm, and the minimum speed calculated in step S22 is 28 rpm, the maximum speed setting value is left as the initial value of 30 rpm and the minimum speed is 27 rpm. In this case, the maximum speed setting value is 25 rpm.

As a result, even if the power system power supply voltage is low and it is not possible to drive at the preset maximum speed stored in advance, the speed is changed to the set value of the maximum speed that can actually be driven, so speed control is possible and is always constant. It becomes possible to drive at a speed.

Further, in this embodiment, an example of determining whether or not to change the set value of the maximum speed depending on whether or not the vehicle can be driven at the maximum speed has been described, but the present invention is not limited to this, and the drive voltage is the power. It may be judged whether or not the voltage supplied from the system power supply voltage is reached (whether or not it is limited).

Further, in this embodiment, an example in which the setting value of the maximum speed is changed when the power is turned on has been described, but the present invention is not limited to this, and the maximum speed setting is periodically changed or the setting is instructed by the user. The maximum speed may be changed. Alternatively, when the movable optical member is driven by the operation of the operation unit 130 by the user, the processes of steps S22 to S24 may be executed for the drive to change the set value of the maximum speed. In that case, the determination in step S23 is not the driving at the maximum speed, but the determination as to whether or not the driving can be performed with respect to the speed command value calculated from the operation unit 130. Further, when the set value of the maximum speed is changed in step S24, the set value may be stored as an initial value.

Further, in this embodiment, an example of driving from the wide-angle end to the telephoto end has been described, but the present invention is not limited to this, and the drive may be performed from the telephoto end to the wide-angle end, or both directions may be driven. You can do it. Further, a part of the movable area may be driven instead of the entire movable area. For example, only the region with the heaviest drive load may be driven.

Further, in this embodiment, an example of lowering the set value of the maximum speed when the driving at the maximum speed cannot be performed has been described, but the present invention is not limited to this. For example, if it is possible to drive at the maximum speed and there is a margin in the power supply voltage supplied to the maximum value of the drive voltage, increase the maximum speed setting value or increase the maximum speed. The set value may be changed so as to return the set value to the original initial value.

Hereinafter, the lens apparatus according to the third embodiment of the present invention will be described with reference to FIGS. 6 to 8. In this embodiment, an example of detecting a change in the drive load from the drive current and changing the set value of the maximum speed will be described. When a constant drive voltage is applied to the DC motor 160, the drive speed fluctuates depending on the drive load. Therefore, even if the power system power supply voltage does not fluctuate, if the drive load fluctuates, it may not be possible to drive at the set maximum speed. For example, when the ambient temperature drops, the drive load increases due to heat shrinkage of the housing member and the viscosity of the lubricant, and even if the power system power supply voltage does not fluctuate, the maximum driveable speed decreases. To do. In this embodiment, a response assuming such a problem will be described.

FIG. 6 shows the configuration of the lens device according to the third embodiment of the present invention.
Components similar to those described in FIG. 1 are designated by the same reference numerals, and description thereof will be omitted.

In addition to the configurations of the first and second embodiments, the lens device of this embodiment detects the drive current flowing through the DC motor 160 when the zoom lens 110 is driven, and outputs the current detection unit (current detection means) 190 to the CPU 120. Has. Further, the storage unit 170 stores speed current information indicating the relationship between the drive speed and the drive current when a predetermined voltage (12 V in this embodiment) corresponding to the power system power supply voltage is applied to the DC motor 160. .. Further, the drive current value at the time of maximum speed drive in the initial state is stored in advance.

FIG. 7 is a graph showing an example of velocity / current information, and is a graph showing the relationship between the drive speed and the drive current when 12 V is applied to the DC motor 160. The speed / current information may be stored in the storage unit 170 as table data or as an equation. Further, the drive current value at the time of maximum speed drive in the initial state (state under the design condition) is 10 mA. Here, the drive current value at the time of maximum speed drive is the average value of the drive current in the entire drive range (from the wide-angle end to the telephoto end in the case of a zoom lens) or the average value of the drive current in a predetermined drive range. , Or a current value typified by a drive current value at a predetermined drive position. The drive current and the drive load are in a proportional relationship. If the drive load corresponds to a drive current of 10 mA, it can be driven at a drive speed of up to 35 rpm. That is, even at the drive position where the maximum drive load is required in the entire drive range, it is possible to drive at a drive speed of 35 rpm at the applied voltage, and it is possible to drive at a drive speed of 35 rpm in the entire drive range. Indicates that there is. However, since the drive load is usually not constant over the entire movable range, it is assumed that the maximum speed is set to 30 rpm as the initial value in consideration of the margin. Here, the relationship of the velocity current information illustrated in FIG. 7 is determined by the presupposed applied voltage, and the lower the applied voltage, the slower the drive speed, and the higher the applied voltage, the faster the drive speed. Become a relationship. That is, more generally, it is desirable that the storage unit 170 stores the relationship between the drive voltage, the drive current, and the drive speed, and the set value of the maximum speed is changed based on this relationship. As illustrated in FIG. 7, the relationship between the drive voltage, the drive current, and the drive speed is such that the drive speed decreases as the drive current increases under a constant drive voltage condition, and when the drive voltage decreases, It has the characteristic of shifting so that the drive speed decreases.

FIG. 8 is a flowchart showing the flow of changing the set value of the maximum speed of this embodiment.
First, in step S31, it is determined whether or not there is an input of a command signal from the operation unit 130. Step S31 is maintained until there is an input, and when there is an input of a command signal, the process proceeds to step S32. In step S32, the zoom lens 110 is driven according to the command signal. Next, in step S33, the current detection unit 190 detects the drive current of the DC motor 160 when the zoom lens 110 is driven. Next, in step S34, it is determined whether or not the drive current detected in step S33 has changed from the drive current in the initial state stored in advance. Judgment as to whether or not there is a change is made based on the method of setting the drive current value at the time of maximum speed drive as already exemplified. If it is determined that there is no change in the detected representative value of the drive current, the process returns to step S31. If it is determined that the change has occurred, the process proceeds to step S35. In step S35, the maximum drive speed at the drive current is obtained from the representative value of the drive current detected in step S33 based on the speed current information stored in the storage unit 170, and the margin is taken into consideration to obtain the maximum speed. Change the setting value. For example, when the drive current detected in step S33 is 20 mA, the maximum drive speed is 32 rpm from the speed current information shown in FIG. 7, and the maximum speed is set to 27 rpm in consideration of the margin. ..

As described above, even if the power system power supply voltage does not fluctuate, the drive load fluctuates, so that even if the drive cannot be driven at the maximum speed stored in advance, the drive can always be performed at a constant speed.

Further, in this embodiment, an example in which the power system power supply voltage is constant has been described, but the present invention is not limited to this, and the same applies even when the power system power supply voltage fluctuates. For example, the velocity / current information at a plurality of applied voltages may be stored, and the velocity / current information of an appropriate applied voltage may be used according to the power system power supply voltage.

Further, in this embodiment, an example of storing speed current information has been described, but the present invention is not limited to this, and since the drive current and the drive load are in a proportional relationship, the relationship between the drive speed and the drive load is shown. The speed load information may be stored.

By configuring an image pickup apparatus having the lens apparatus of the present invention described above and an image pickup device that receives an optical image formed by the lens apparatus, an image pickup apparatus that enjoys the effects of the lens apparatus of the present invention can be realized. Can be done.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made within the scope of the gist thereof.

110 zoom lens (movable optical member)
120 CPU (control means, setting means)
140 Position detection unit (position detection means)
150 Drive unit (drive means)
160 DC motor (driving means)

Claims (9)

In the lens apparatus which have a driving means for driving the movable optical member and the movable optical member,
Speed of the movable optical member in the case of driving the movable optical member by said driving means in the supplied power supply voltage, the drive current of said drive means, based on at least one of the driving voltage of said driving means, said movable optical Setting means for setting the maximum speed of the member,
Lens apparatus characterized by a control means for controlling the speed of said movable optical member by the drive means the maximum speed as the upper limit speed of. The setting means, based on the drive voltage of the drive means in the case of driving the movable optical member by said driving means in the power supply voltage, a lens according to claim 1, characterized in that setting the maximum speed apparatus. It has a speed detecting means for detecting the speed of the movable optical member, and has
The setting means, to claim 1, characterized in that said on the basis of the speed detected by the speed detecting means when driving the movable optical member by said driving means in the power supply voltage, to set the maximum speed The lens device described. The setting means, based on the minimum speed detected by the speed detecting means when driving the movable optical member by said driving means in the power supply voltage, according to claim 3, characterized in that to set the maximum speed The lens device described in. It has a current detecting means for detecting the driving current of the driving means, and has
The setting means, based on the drive current detected by said current detecting means, the lens apparatus according to claim 1, characterized in that to set the maximum speed. The setting means,-out based on the average value of the driving current in the driving range of a specific case of driving the movable optical member by the drive means at a specific driving voltage, that to set the maximum speed The lens device according to claim 5 . The setting means, characterized in that said driving means by-out based on the drive voltage of the drive current and the drive means in a specific driving position when driving the movable optical member, to set the maximum speed The lens device according to claim 5 . Lens apparatus according to claim 6 or claim 7, characterized in that that have a storage means for storing a relationship between the drive voltage and the drive current and the maximum speed. Imaging apparatus characterized by comprising a lens device according to any one, and an image sensor for receiving an optical image formed by the lens apparatus of claims 1 to 8.

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