JP3287497B2 - Driving device for lens for TV camera - Google Patents

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 drive unit of a lens unit is determined. It is about.

[0002]

2. Description of the Related Art Conventionally, in the case of a large broadcast television camera installed in a studio, or when a portable video camera is mounted on a tripod for photographing, the pan or pan of the television camera or video camera is used. A handle for performing the tilt operation is installed, and a grip-shaped lens controller is attached to the handle and the like, and the operation of the lens controller enables a focus operation, a zoom operation, an iris operation, an extender operation, and the like of the lens. To do.

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

[0004]

By the way, the drive current to each drive unit of the lens unit in the TV camera as described above is supplied from a constant voltage power supply of the TV camera body or a battery built in the TV camera body. The maximum current value that can be supplied to each drive unit is set to a predetermined value. In particular, 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, the miniaturization of TV cameras has progressed,
In response to this, the power supply for supplying current has also become smaller, so the maximum current output is also limited.
The degree is determined.

Accordingly, for example, when a predetermined control signal is input to a drive unit of a focus lens system or a zoom lens system, each lens system reaches its end position, and thereafter, the control signal is still input. In such a case, a useless current is supplied to this drive unit, so that a necessary drive current may not be distributed to another drive unit.

Further, for example, when a plurality of types of control signals are inputted at the same time, a current larger than the above-mentioned maximum current value is required to drive all of the driving units corresponding to the control signals. May not operate normally, or the intended driving 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 driving unit in the lens unit is determined, the efficiency of the current distributed to each driving unit. It is another object of the present invention to provide a television camera lens driving device in which these driving units can operate normally.

[0009]

According to a first aspect of the present invention, a driving device for a lens for a television camera is provided in which each driving unit incorporated in a lens unit of the television camera inputs a control signal corresponding to each of the driving units. In a television camera lens driving device driven in accordance with the position, a position detection unit for detecting a movement position of a mechanism driven by each of the driving units, and the mechanism is terminated at a terminal based on a position signal from the position detection unit. A moving position judging unit for judging whether or not the mechanism has moved to a position, and, when the moving position judging unit judges that the mechanism has moved to its end position, send it to a driving unit relating to this mechanism. A current limiter for reducing a current value to a predetermined value.

In the second driving device for a television camera lens of the present invention, each driving unit built in the lens unit of the television camera is driven in response to input of a control signal corresponding to each of these driving units. When a control signal corresponding to each of the driving units is input, a control signal identification unit that identifies the type of the input control signal, and a plurality of the control signals are input. In this case, the driving timing pattern of each driving unit according to the input control signal is adjusted so that the total current value for driving each of the driving units is always equal to or less than a predetermined current value. A drive timing storage unit storing for each combination of control signals, and a plurality of the control signals being input substantially simultaneously When the type is identified by the control signal identification unit, a drive timing pattern of each of the drive units according to the combination of the type is output from the drive timing storage unit, and the respective drive timing patterns are output based on the drive timing pattern. And a drive timing control section for outputting a drive signal to the drive section.

[0011] The "substantially simultaneous" means that a plurality of control signals are simultaneously input into the apparatus and that a control signal relating to another drive unit is driven while one drive unit is being driven. This includes the case where the data is input into the device.

[0012]

According to the first television camera lens driving device, the movement position of the mechanism driven by each drive unit is detected, and based on the detection result, whether each mechanism has moved to its end position is determined. When the control signal is determined to have been moved to the end position and the control signal is continuously being input, the current value to the drive unit that drives the mechanism is reduced to a predetermined value, It is possible to prevent a useless current from being supplied to the drive unit.

Thus, the efficiency of the drive current can be improved, and the required drive current can be distributed to other drive units.

According to the second television camera lens driving device, the type of the input control signal is identified, and when a plurality of control signals are input at substantially the same time, the predetermined control signal is determined. These drive units are driven based on the drive timing of the drive units according to the control signal, so that 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 simultaneously, normal operation of each drive unit can be ensured 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. The camera body 2 is a support for a pan head 4 capable of panning in a swiveling direction and tilting up and down.
Supported on 4c. This head 4 has a fixed leg 4a
A camera platform main body 4b is installed, the camera platform main body 4b is driven to turn left and right with respect to the leg 4a, and the support base 4c is driven to tilt vertically with respect to the camera platform main body 4b, The pan and tilt drive servo mechanism (not shown) is provided in the camera platform body 4b.

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

The operation unit 6 is installed separately from the television camera 1 so as to perform remote operation via the RS232C cable 5. The joystick, zoom switch,
Various command signals are sent to the camera platform 4 based on the operation of the operator (cameraman) of the various operating members 7 such as the focus knob and the speed adjustment unit. On the other hand, communication signals such as confirmation signals are also transmitted from the camera platform 4. The operation unit 6
To operate the zoom, focus, iris, extender, and other controls.

Further, a CRT 8 is connected to the operation unit 6. The image taken by the television camera 1 is displayed on the CRT 8, and the diagnosis result of the movable part 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 supply 10 provided in the television camera body 3 is input to the comprehensive current monitoring circuit 20 of the lens driving device 3a, and the total driving current is calculated. Is detected.

Next, each mechanism to be driven by this drive current (zoom lens drive mechanism, focus lens drive mechanism, iris diaphragm mechanism, extender lens drive mechanism)
Are input to the driving circuits 24a to 24d of the driving motors 26a to 26d, and the values of the currents flowing through the driving circuits 24a to 24d are monitored and limited by the current value monitoring / limiting circuits 22a to 22d. It will be. Each current value monitoring / limiting circuit
The drive currents output from 22a to 22d are the drive circuits 24 of each mechanism.
The motors 26a to 26d are driven by drive currents input to the drive circuits 24a to 24d.

The amount of rotation of each of the motors 26a to 26d is detected by each of the potentiometers 28a to 28d and output as a position signal of each mechanism. This position signal is converted by the voltage conversion circuit 30 into CP.
U is converted into a voltage level for U and the current value is controlled by a current value control circuit (CP
U) 32.

On the other hand, a drive signal is sent from the controller 34 outside the apparatus to each of the drive circuits 24a to 24d, and each of the drive circuits 24a to 24d starts operating in response to the input of the drive signal. Will do. The controller 34 controls the current value from a current value control circuit (CP
U) Current value control signal (control signal) to instruct 32
Are output at the same time as the drive signal. This signal is converted to a voltage level for the CPU by the voltage conversion circuit 36, and then input to the current value control circuit (CPU) 32.

The current value control circuit (CPU) 32 receives the condition data stored in the condition data storage circuit 38. The current value control circuit (CP)
U) 32 sends a predetermined current value limiting signal to each of the current value monitoring / control circuits 22a to 22d based on the input signals and data to adjust the current value.

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

Next, the operation of the driving device shown in FIG. 1 will be described with reference to the flowchart shown in FIG.

First, an ambient temperature value detected by a temperature detector (not shown) (disposed in the lens unit 3a) is read by a current value control circuit (CPU) 32 (S30).
1) Subsequently, an angle detection unit (lens unit not shown)
The current value control circuit (CPU) 32 reads the angle value of the lens mechanism and the like detected by the current value control circuit (CPU 3) (S3).
2).

The current value control circuit (CPU) 32 drives basic 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 their drive timings) are read from the condition data storage circuit 38 (S3). The basic data for driving according to the temperature value and the angle value are input in a table format to the condition data storage circuit 38, and when the temperature value and the angle value are input to the condition data storage circuit 38, The driving basic data is input to a current value control circuit (CPU) 32.

The reason why the basic driving data is changed in accordance with the above-mentioned temperature value and the above-mentioned angle value is that when these temperature value and the angle value change, the required driving current value also changes.

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

When the battery provided in the camera body 2 is used instead of the external power supply 10, the above-mentioned maximum current value is set in consideration of the capacity of the battery.

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

The reason why the drive current value is excessive may be that the mechanism has reached its end position of movement and a large load is applied. Therefore, the position signals from the potentiometers 28a to 28d are used. The current value control circuit (CPU) 32 reads the signal (S6), and then detects a change in the current value control signal (control signal) from the external controller 34 (whether or not it is at the H level) in the current value control circuit (CPU). It is read at 32 (S7), and it is determined whether or not the mechanism relating to the current value control signal (control signal) determined to have undergone a signal change has reached its movement end position (S8). For example, in the case of a zoom lens mechanism, it is determined whether or not the telephoto end or the wide-angle end has been reached, and in the case of the iris diaphragm mechanism, it has reached the maximum open end or the minimum open end. Will be determined.

As a result of this determination, if none of the mechanisms whose current value control signal has changed have reached their movement end position, the process proceeds to S10, and if they have reached their movement end position, the current value of the mechanism has changed. A current limiting signal is sent to the monitoring / limiting circuits 22a to 22d to limit the driving current to the driving motors 26a to 26d so that the total driving current flowing through the comprehensive current monitoring circuit 20 is within the maximum current value described above. (S9).

Next, it is considered that a plurality of drive circuits 24a to 24d are driven as a cause of the sum of the drive current values exceeding the maximum current value. Therefore, the input current value control signal (control signal) It is determined whether or not the sum of the drive current values when driving the drive circuits 24a to 24d related thereto exceeds the maximum current value. The drive current value to each of the drive circuits 24a to 24d is a current value limit / monitoring circuit 22a.
To d, and the value is detected by a current value control circuit (CP
U) 32. As a result of this determination, if it is not exceeded, the process returns to S1, and if it is determined that it exceeds, the process proceeds to S11 (S10). In step S11, the current value control circuit (CPU) 32 sends predetermined drive circuits 24a to 24d based on predetermined drive sequences and drive timings (stored in the condition data storage circuit 38) of the drive circuits 24a to 24d.
The current limit signals are output to the current value monitoring / limiting circuits 22a to 22d, and the drive circuits 24a to 24d are driven at timings such that the total drive current does not always exceed the maximum current value.

The setting of the drive sequence and the drive timing means that, 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. This is a setting that drives the focus lens mechanism after this is completed, and drives the extender lens mechanism after this is completed. The setting of the drive sequence and the drive timing may be any setting as long as the total of the drive current values does not exceed the maximum current value, and the drive of each mechanism may be alternately performed in a time-division manner. Good.

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

That is, each drive signal output from the external controller 40 for driving the motors 50a to 50d related to each mechanism is input to the control circuit 42. These drive signals are used as drive currents as they are.

Further, in the judgment circuit 46, the driving circuits 48a to 48d are controlled based on the condition data as the reference data stored in the condition data storage circuit 44 in advance according to the type of the driving signal input to the control circuit 42 at the same time. The drive order and the drive timing are determined. The determination of the drive sequence and the drive timing is based on the condition that the sum of the drive currents does not always exceed a predetermined maximum current amount. Based on this determination, a predetermined signal among the respective drive signals input from the controller 40 to the control circuit 42 is sent to the respective 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 the switches are cut off by the input of the signal from the determination circuit 46. I have.

The driving circuits 48a to 48d to which the driving signals are inputted drive the corresponding driving motors 50a to 50d, whereby the zoom lens mechanism, the focus lens mechanism, the extender lens mechanism and the other mechanisms are operated in a predetermined manner. In the order and timing.

The 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 using 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 constituted by software.

That is, first, the type of the drive signal input from the controller 40 to the control circuit 42 is read by the determination circuit 46 (S1). It is determined whether or not the drive signal from the controller 40 does not change by this reading (whether or not the H level has been reached). If the result of this determination is that a drive signal has not been input, the process returns to S1 and is input. If yes, go to the next step (S2).

Thereafter, when it is determined that the drive signal is being 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 the extenders.

That is, first, it is determined whether or not a zoom drive signal has been input (S3), and if so, 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 an extender drive signal has been input (S7), and if so, the extender drive circuit 48d is driven (S8).

Although not shown in the flowchart of FIG. 5, it is possible to drive the iris drive circuit 48c at a predetermined timing in accordance with the input of the iris drive signal.

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

For example, in the flowchart shown in FIG. 3, after S11, another condition flow for examining the cause of the excessive drive current and coping with the cause can be appropriately added.

The drive sequence and the drive timing can be selected as appropriate. For example, in the flowchart shown in FIG. 5, the drive of one mechanism is completed and then the drive of the next mechanism is started. But 2
It is also possible to drive one mechanism or three mechanisms simultaneously. For example, the zoom lens mechanism and the focus lens mechanism are driven at the same time, and if an iris drive signal is input during this drive, the iris diaphragm mechanism is also driven at the same time. During this drive, the extender drive signal is input. In this case, the drive of the extender lens mechanism is set to be in a standby state. Further, for example, when the zoom lens mechanism is driven, the extender lens mechanism is driven, and in this state, if a drive signal for focusing is input, the drive of the focus lens mechanism is performed after the drive of the extender lens mechanism ends. 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 its movement end position, and it is determined that the movement has been reached. In such a case, the drive current for driving the mechanism is reduced, and when a drive signal for a plurality of mechanisms is inputted, the drive of 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 driving units while improving the efficiency of the driving current distributed to the driving units.

[Brief description of the drawings]

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

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

FIG. 3 is a flowchart for explaining the operation of the apparatus shown in FIG. 1;

FIG. 4 is a block diagram showing a device according to another embodiment different from the device shown in FIG. 1;

FIG. 5 is a flowchart for explaining a part of the operation of the apparatus shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Television camera 2 Camera body 3 Lens unit 3a Lens driving device 4 Head 10 Power supply 20 Total current monitoring circuit 22a-d Current value limiting / monitoring circuit 24a-d, 48a-d Drive circuit 26a-d, 50a-d Drive motor 28a to d Potentiometer 32 Current value control circuit 34, 40 Controller 38, 44 Condition data storage circuit 42 Control circuit 46 Judgment circuit

Claims (2)

(57) [Claims] An apparatus for driving a lens for a television camera, wherein each driving unit built in a lens unit of the television camera is driven in response to an input of a control signal corresponding to each of the driving units. A position detection unit that detects a movement position of the mechanism to be performed; a movement position determination unit that determines whether the mechanism has moved to its end position based on a position signal from the position detection unit; A current limiting unit that reduces a current value to be sent to a drive unit according to the mechanism to a predetermined value when the determination unit determines that the mechanism has moved to its end position. Of a lens for a television camera. 2. A television camera lens driving device in which respective driving units incorporated in a lens unit of a television camera are driven in response to input of a control signal corresponding to each of the driving units. A control signal identification unit that identifies the type of the input control signal when a control signal is input, and a current value for driving each of the drive units when a plurality of the control signals are input. A drive timing storage unit in which the total is always adjusted to be equal to or less than a predetermined current value, and a drive timing pattern of each drive unit related to the input control signal is stored for each combination of the control signals. A plurality of the control signals are input substantially simultaneously, and the types thereof are identified by the control signal identification unit. A driving timing control unit that outputs a driving timing pattern of each of the driving units according to the combination of the types from the driving timing storage unit, and outputs a driving signal to each of the driving units based on the driving timing pattern. A driving device for a lens for a television camera, comprising: