JPH06326908A - Device for driving lens for television camera - Google Patents

Abstract

PURPOSE:To efficiently use currents distributed to respective driving parts and to normally operate these driving parts by restricting a driving current for a mechanism when the mechanism arrives at its moving end position, and when plural mechanism driving signals are inputted, setting up the priority order of drive. CONSTITUTION:The sum of driving current values, current values for driving respective driving circuits 24a to 24d, position signals indicating the positions of respective driving motors 26a to 26d, a current value limiting signal from a controller 34, and reference data from a conditional data storing circuit 38 are inputted to a current value control circuit (CPU) 32. At the time of judging the excess of a driving current when the mechanism driven by the motors 26a to 26d arrives at its moving end position or plural control signals are simultaneously inputted, limit signals are outputted to prescribed current value monitoring/limiting circuits 22a to 22d to adjust the driving current.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for driving a lens for a television camera, and more particularly to a device for driving a lens for a television camera in which a current capacity for driving each driving portion of a lens unit is determined. It is about.

[0002]

2. Description of the Related Art Conventionally, in a large-scale television camera for broadcasting which is installed in a studio, or when a handy-type video camera is mounted on a tripod for photographing, the pan or In addition to installing a handle for tilting, attach a grip type lens controller to this handle etc., and operate the lens controller to focus, zoom, iris or extender the lens. I'm trying to do.

That is, a control signal from the lens controller is input to a lens driving section of a lens unit via a code, and by operating the lens controller, each servo motor arranged in the lens driving section is driven to drive each lens. It is configured to adjust the position of the mechanism and the like.

[0004]

By the way, the driving current to each driving unit of the lens unit in the television camera as described above is supplied from a constant voltage power source of the television camera body or a battery built in the television camera body. Therefore, the maximum current value that can be supplied to each drive unit is set to a predetermined value. Particularly in recent years, the lens system has been improved in performance, and the degree of electric control has been advanced, so that the current consumption has been increased.

On the other hand, TV cameras have become smaller,
In response to this, the power supply for current supply is also becoming smaller, so there is a limit to the maximum current output, and the value is, for example, 2A.
It is determined by the degree.

Therefore, for example, when a predetermined control signal is input to the drive unit of the focus lens system or the zoom lens system, each lens system reaches its end position, and the control signal is still input after that. However, there is a risk that a wasted current will be supplied to this drive unit and the necessary drive current cannot be distributed to other drive units.

Further, for example, when a plurality of types of control signals are input at the same time, a current higher than the above-mentioned maximum current value is required to drive all the drive units corresponding to these control signals, and eventually each drive unit is driven. May not operate normally, or the planned drive unit may not be driven.

The present invention has been made in view of such circumstances, and when the maximum current value for driving each drive unit in the lens unit is set, the efficiency of the current distributed to each drive unit is set. It is an object of the present invention to provide a driving device for a lens for a television camera, in which the driving units can perform normal operation while being able to realize the above-mentioned driving.

[0009]

According to a first aspect of the present invention, there is provided a lens driving device for a television camera, wherein each driving portion incorporated in a lens unit of the television camera receives a control signal corresponding to each driving portion. In a device for driving a lens for a television camera driven in accordance with the above, a position detecting unit that detects a moving position of a mechanism driven by each of the driving units, and the mechanism ends based on a position signal from the position detecting unit. And a moving position determining unit that determines whether or not the mechanism has moved to a position, and when the moving position determining unit determines that the mechanism has moved to its terminal position, sends it to the drive unit related to this mechanism. It is characterized by comprising a current limiting unit for reducing the current value to a predetermined value.

Further, in the second television camera lens driving device of the present invention, each driving section built in the lens unit of the television camera is driven in response to the input of a control signal corresponding to each of these driving sections. In a television camera lens driving device, when a control signal corresponding to each driving unit is input, a control signal identifying unit that identifies the type of the input control signal and a plurality of the control signals are input. If the total of the current value for driving each drive unit is adjusted to be always a predetermined current value or less, the pattern of the drive timing of each drive unit according to the input control signal is A drive timing storage section for storing each control signal combination and a plurality of the control signals are input substantially at the same time. When the type is identified by the control signal identifying unit, the drive timing storage unit outputs the drive timing pattern of each drive unit related to the combination of the type, and each of the drive timing patterns is output based on the drive timing pattern. And a drive timing control unit that outputs a drive signal to the drive unit.

The term "substantially simultaneously" means that a plurality of control signals are simultaneously input into the apparatus, and that one drive unit is being driven while the control signals of the other drive units are the same. It also includes the case where it is input in the device.

[0012]

According to the first lens driving device for the television camera, the moving position of the mechanism driven by each driving unit is detected, and based on the detection result, it is determined whether or not each mechanism has moved to its end position. When it is determined that the mechanism is moving to the end position and the control signal is continuously input, the current value to the drive unit that drives this mechanism is decreased to a predetermined value. It is possible to prevent unnecessary current from being supplied to the drive unit.

As a result, the efficiency of the drive current can be improved, and the necessary drive current can be distributed to the other drive units.

According to the second television camera lens driving device described above, the types of the input control signals are identified, and when a plurality of control signals are input substantially at the same time, these are determined in advance. These drive units are driven based on the drive timing of the drive units related to the control signals, and the total current supplied to the drive units is always kept below the maximum current capacity of the power supply. Even if a plurality of types of control signals are input substantially at the same time, it is possible to ensure the normal operation of each drive unit while improving the efficiency of the drive current.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows the overall configuration of a camera platform control device equipped with a lens driving device for a television camera according to this embodiment.

The television camera 1 is composed of a camera body 2 and a lens unit 3, and the camera body 2 is a support base for a pan 4 which can pan in the turning direction and tilt in the vertical tilting direction.
It is supported by 4c. This platform 4 has a fixed leg 4a.
The platform main body 4b is installed on the platform 4, the platform base 4b is pivotally driven in the left-right direction with respect to the legs 4a, and the support base 4c is tilted vertically with respect to the platform base 4b. A servo mechanism (not shown) for driving the pan and tilt is installed in the platform body 4b.

On the other hand, the lens unit 3 of the TV camera 1
The lens driving device 3a is provided with a servo mechanism (not shown) for driving each of zoom, focus, iris, and extender.

Further, the operation unit 6 is installed separately from the television camera 1 via the RS232 C cable 5 so as to be remotely operated, and the joystick, the zoom switch installed in the operation unit 6,
Various command signals are sent to the camera platform 4 side based on the operation of the operator (cameraman) of various operating members 7 such as the focus knob and the speed adjusting unit, while communication signals such as confirmation signals are also transmitted from the camera platform 4 side. The operation unit 6
And the operation of the zoom, focus, iris, extender, and other controls can be performed.

Further, a CRT 8 is connected to the operation unit 6. An image taken by the television camera 1 is displayed on the CRT 8, and a diagnostic result of the movable portion is displayed together with the image.

FIG. 1 is a block diagram showing a driving device for a television camera according to an embodiment of the present invention.

That is, in this driving device, the driving current output from the constant voltage power source 10 arranged in the television camera body 3 is input to the total current monitoring circuit 20 of the lens driving device 3a, and the total driving current is calculated. To be detected.

Next, the drive current is driven by each mechanism (zoom lens drive mechanism, focus lens drive mechanism, iris diaphragm mechanism, extender lens drive mechanism).
Is input to the drive circuits 24a to d of the drive motors 26a to d, and the value of the current flowing in each drive circuit 24a to d is monitored and limited by each current value monitoring / limitation circuit 22a to d. It will be. Each current value monitor / limit circuit
The drive current output from 22a-d is the drive circuit of each mechanism.
The motors 26a to 26d are driven by the drive currents input from the drive circuits 24a to 24d.

The amount of rotation of each motor 26a-d is detected by each potentiometer 28a-d and output as a position signal for each mechanism. This position signal is CP by the voltage conversion circuit 30.
Converted to the voltage level for U, the current value control circuit (CP
U) 32 is input.

On the other hand, a drive signal is sent from the controller 34 outside the apparatus to each drive circuit 24a to 24d, and each drive circuit 24a to 24d starts its operation in response to the input of the drive signal. Will be done. The controller 34 controls the current value by controlling the current value control circuit (CP
U) Current value control signal (control signal) instructing 32
Is output at the same time as the drive signal, and this signal is input to the current value control circuit (CPU) 32 after being converted to a voltage level for CPU in the voltage conversion circuit 36.

Further, the current value control circuit (CPU) 32 is adapted to be input with the condition data stored in the condition data storage circuit 38. This current value control circuit (CP)
U) 32 sends a predetermined current value limiting signal to each current value monitoring / control circuit 22a to 22d based on each input signal and each data, and adjusts the current value.

The current value information monitored by the current value monitoring / limitation circuits 22a to 22d is the current value control circuit (C
PU) 32.

Next, the operation of the drive device shown in FIG. 1 will be described with reference to the flow chart shown in FIG.

First, the ambient temperature value detected by a temperature detector (not shown) (disposed in the lens unit 3a) is read by the current value control circuit (CPU) 32 (S
1), followed by an angle detection unit (lens unit, not shown)
The angle value of the lens mechanism or the like detected by (disposed in 3a) is read by the current value control circuit (CPU) 32 (S
2).

The current value control circuit (CPU) 32 is a basic driving data as reference data according to the input temperature value and angle value (the drive circuit to be driven according to the input control signal and current value). 24a to 24d and data defining the driving timing thereof are read from the condition data storage circuit 38 (S3). The basic driving data corresponding to the temperature value and the angle value is input in the condition data storage circuit 38 in a table format. When the temperature value and the angle value are input to the condition data storage circuit 38, The basic driving data is input to the current value control circuit (CPU) 32.

The drive basic data is changed according to the temperature value and the angle value because the required drive current value changes when the temperature value and the angle value change.

Next, the maximum current value that can be used as the drive current, which is determined in consideration of the capacity of the power source 10 and the like, is set (S4). This maximum current value is set to, for example, about 2 A, but may be appropriately selected according to the capacity of the power source 10 and the like.

Even when a battery arranged in the camera body 2 is used instead of the external power source 10, the maximum current value is set in consideration of the capacity of the battery.

Next, the maximum current value as the reference value set as described above is compared with the drive current value detected by the total current monitoring circuit 20, and this drive current value exceeds the maximum current value. If not, the process returns to S1 described above, and if it exceeds, the process proceeds to the next step in order to determine the cause and take action (S5).

As a cause of the drive current value becoming excessive, first, it is conceivable that the mechanism has reached the end position of its movement and a large load is applied. Therefore, the position signals from the potentiometers 28a to 28d are detected. The current value control circuit (CPU) 32 reads it (S6), and then the signal change (whether it is at H level) of the current value control signal (control signal) from the external controller 34 is detected by the current value control circuit (CPU). It is read at 32 (S7), and it is judged whether or not the mechanism relating to the current value control signal (control signal) which has been determined to have changed signal has not reached the movement end position (S8). For example, if it is a zoom lens mechanism, it will be judged whether it has reached the telephoto side end or the wide angle side end, and if it is an iris diaphragm mechanism, it will reach the maximum opening side end or the minimum opening side end. It will be judged whether or not.

As a result of this judgment, if none of the mechanisms in which the current value control signal has changed is at the movement end position, the process proceeds to S10, and if it is at the movement end position, the current value related to the mechanism is reached. A current limiting signal is sent to the monitoring / limitation circuits 22a-d to limit the drive currents to the drive motors 26a-d so that the total drive current flowing through the total current monitor circuit 20 is within the maximum current value described above. Yes (S9).

Next, it is considered that a plurality of drive circuits 24a to 24d are driven as a cause of the total of the drive current values exceeding the maximum current value. Therefore, the input current value control signal (control signal) Of the drive circuit 24a to 24d is determined, and it is determined whether or not the total drive current value when the drive circuits 24a to 24d are driven exceeds the maximum current value. The drive current value to each drive circuit 24a to 24d is the current value limiting / monitoring circuit 22a.
~ D, the value is detected by the current value control circuit (CP
U) 32. If the result of this determination is that it does not exceed, then the procedure returns to S1, and if it is determined that it exceeds, then the procedure advances to S11 (S10). In S11, the current value control circuit (CPU) 32 determines the predetermined driving circuits 24a to 24d based on the predetermined driving order and driving timing of these driving circuits 24a to 24d (stored in the condition data storage circuit 38).
A current limiting signal is output to the current value monitoring / limiting circuits 22a to 22d according to the above, and the driving circuits 24a to 24d are driven at timings such that the total driving current does not always exceed the maximum current value.

The setting of the driving order and the driving timing means, for example, when the current value control signals of the zoom, focus and extender are simultaneously input to the current value control circuit (CPU) 32, the zoom lens mechanism is first set. The setting is such that the focus lens mechanism is driven after driving, and the extender lens mechanism is driven after this is completed. The drive sequence and drive timing may be set so that the total drive current value does not exceed the maximum current value, and the drive of each mechanism may be performed alternately in a time-division manner. Good.

FIG. 4 is a block diagram showing an apparatus according to an embodiment of the present invention different from the apparatus shown in FIG. This drive is
The driving order and the driving timing can be appropriately set based on the input of the driving signal from the external controller 40.

That is, the drive signals for driving the motors 50a to 50d associated with the respective mechanisms, which are output from the external controller 40, are input to the control circuit 42. These drive signals are directly used as drive currents.

Further, in the judging circuit 46, the driving circuits 48a to 48d of the driving circuits 48a to 48d based on the condition data as reference data previously stored in the condition data storing circuit 44 in accordance with the kind of the driving signal inputted to the control circuit 42 at the same time. The driving order and driving timing are determined. The determination of the driving order and the driving timing is on condition that the total driving current does not always exceed a predetermined maximum current amount. Based on this determination, a predetermined signal of the drive signals input from the controller 40 to the control circuit 42 is sent to the drive circuits 48a to 48d,
Alternatively, the transmission is stopped. That is, the control circuit 42 is composed of a switch group in which switches corresponding to the respective drive signals are arranged in parallel, and each switch can be turned on and off by the input of a signal from the judgment circuit 46. There is.

The drive circuits 48a to 48d to which the drive signals are input in this manner drive the corresponding drive motors 50a to 50d, whereby the zoom lens mechanism, the focus lens mechanism, the extender lens mechanism and other mechanisms are predetermined. Will be driven in the order and timing.

Judgment and control circuit by the judgment circuit 46
The switching operation of the switch group with respect to 42 may be performed by hardware by a logic circuit or may be performed by software using a program.

FIG. 5 is a flow chart for explaining the operation of the apparatus when the judgment circuit 42 is constructed by software.

That is, first, the determination circuit 46 reads the type of the drive signal input from the controller 40 to the control circuit 42 (S1). By this reading, it is determined whether the drive signal from the controller 40 does not change (whether it is at the H level or not). As a result of this determination, if the drive signal is not input, the process returns to S1 and is input. If there is, proceed to the next step (S2).

After that, when it is determined that the drive signal is input, it is determined what the drive signal is and the drive circuits 48a, b, d corresponding to the drive signal are zoomed, focused, Drive in the order of extenders.

That is, first, it is judged whether or not the zoom drive signal is input (S3), and if it is input, the zoom drive circuit 48a is driven (S4). Next, it is determined whether or not the focus drive signal is input (S
5) If it is input, the focus drive circuit 48b is driven (S6). Thereafter, it is determined whether or not the extender drive signal is input (S7), and if it is input, the extender drive circuit 48d is driven (S8).

Although not shown in the flow chart of FIG. 5, the iris drive circuit 48c can be driven at a predetermined timing in response to the input of the iris drive signal.

The apparatus of the embodiment of the present invention is not limited to that of the above-mentioned embodiment, and various modifications can be made.

For example, in the flowchart shown in FIG. 3, after S11, it is possible to appropriately add another condition flow for investigating the cause of the excessive drive current and coping with it.

Further, the driving order and driving timing can be appropriately selected. For example, in the flow chart shown in FIG. 5, the driving of one mechanism is finished before the driving of the next mechanism is started. But 2
It is also possible to drive one mechanism or three mechanisms simultaneously. For example, if the zoom lens mechanism and the focus lens mechanism are driven at the same time and the iris drive signal is input during this drive, the iris diaphragm mechanism is also driven at the same time, but the extender drive signal is input during this drive. If so, the drive of the extender lens mechanism is set to a standby state. Further, for example, when the zoom lens mechanism is driven, the extender lens mechanism is driven, and when the focus drive signal is input in this state, the focus lens mechanism is driven after the drive of the extender lens mechanism is completed. It is also possible to set.

[0052]

As described above, in the television camera lens driving device of the present invention, it is determined whether or not each mechanism has reached the movement end position, and it is determined that they have arrived. In this case, the drive current for driving that mechanism is reduced, and when the drive signals for multiple mechanisms are input, the drive current for each mechanism is controlled so that the total drive current is within the allowable value. Since the timing is determined, it is possible to ensure the normal operation of these drive units while improving the efficiency of the drive current distributed to the drive units.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a driving device for a television camera lens according to the present invention.

FIG. 2 is a schematic diagram showing an overall configuration of a camera platform control device equipped with a driving device for a lens for a television camera.

3 is a flowchart for explaining the operation of the apparatus shown in FIG.

FIG. 4 is a block diagram showing another embodiment of the apparatus different from the apparatus shown in FIG.

5 is a flowchart for explaining a part of the operation of the apparatus shown in FIG.

[Explanation of symbols] 1 TV camera 2 Camera body 3 Lens unit 3a Lens driving device 4 Pan head 10 Power supply 20 Total current monitoring circuit 22a to d Current value limiting / monitoring circuit 24a to d, 48a to d Driving circuit 26a to d, 50a ~ d Drive motor 28a ~ d Potentiometer 32 Current value control circuit 34, 40 Controller 38, 44 Condition data storage circuit 42 Control circuit 46 Judgment circuit

Claims (2)

[Claims] 1. A driving device for a lens for a television camera, wherein each driving section incorporated in a lens unit of a television camera is driven in response to an input of a control signal corresponding to each of these driving sections. A position detecting section for detecting the moving position of the mechanism, a moving position judging section for judging whether the mechanism has moved to the terminal position based on a position signal from the position detecting section, and the moving position. And a current limiting unit configured to reduce the current value sent to the drive unit related to the mechanism to a predetermined value when the determination unit determines that the mechanism has moved to the terminal position. A drive device for a TV camera lens. 2. A driving device for a lens for a television camera, wherein each driving section built in a lens unit of a television camera is driven according to an input of a control signal corresponding to each of the driving sections, wherein each driving section corresponds to each driving section. When a control signal is input, a control signal identification unit that identifies the type of the input control signal, and a current value for driving each drive unit when a plurality of the control signals are input A drive timing storage unit that stores a drive timing pattern of each drive unit related to the input control signal, which is adjusted so that the total is always a predetermined current value or less, for each combination of the control signals, A plurality of the control signals are input substantially at the same time, and their types are identified by the control signal identifying section. At this time, a drive timing control unit that causes the drive timing storage unit to output a drive timing pattern of each drive unit related to the combination of the types and outputs a drive signal to each drive unit based on the drive timing pattern. A device for driving a lens for a television camera, which is characterized by being provided.