JPH08278438A - Motor driving control device for television lens - Google Patents

Abstract

PURPOSE: To provide the motor driving control device for television lens capable of applying one kind of a lens system in common even when voltage values of power source equipments are different. CONSTITUTION: When the contact piece 12C and the contact piece 12D of an operating switch 12 are respectively abutted on a contact 12A and a contant 12B, a current flows to a voltage detecting circuit 16 and also to a low voltage circuit 20 via a rectifier circuit 14. At this time, when the output voltage of the rectifier circuit 14 is higher than the Zener voltage Vz of a Zener diode D1, the Zener diode D1 is brought into conduction and a transistor Q1 becomes a conducting state. That is, a current flows through the coil 18A of a relay 18, contacts 18A, 18B of the relay 18 are abutted on each other and a voltage dividing circuit constituted of resistors R2 to R5 is formed in the low voltage circuit 20. Consequently, the voltage divided in the voltage dividing circuit is impressed on a motor 22. Besides, when the output voltage of the rectifier circuit 14 is lower than the Zener voltage Vz, the diode D1 is not brought into conduction and, hence, the voltage dividing circuit is not also formed. That is, the voltage almost equal to a power source voltage is impressed on the motor 22. Moreover, this circuit is symmetrical with respect to positive and negative polarities.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor drive controller for a television lens, and more particularly to a surveillance television camera used in banks, convenience stores, etc., and a television used for measurement in factories, laboratories, etc. The present invention relates to a motor drive control device for a television lens used in a camera or the like.

[0002]

2. Description of the Related Art A motor for driving a focus, zoom, iris, etc. of a television lens is connected to a control device and is drive-controlled by turning on and off an operation switch. That is, for example, when adjusting the focus, the operation switch is turned on to drive the motor that engages with the focus ring, and when the focus position is reached, the operation switch is turned off to stop the motor drive and focus is achieved. It is matched.

Since the voltage value of the equipment in which the TV lens motor drive control device is installed may vary depending on the equipment, a lens system having an input voltage corresponding to the voltage value is used.

[0004]

However, in the conventional lens drive control device, for example, the power supply voltage is DC 12 V in some equipment, and DC in some equipment.
Since it is various such as 6V, it is necessary to select an appropriate lens system according to the voltage value of each power supply. That is, when the power supply voltage is DC12V, a lens system driven by a DC12V motor is required. In this case, if a lens system driven by a DC6V motor is used, the rotation speed becomes high and stable. There is a problem that control cannot be performed. As described above, in order to cope with power supplies having various voltage values so as to ensure a stable motor rotation speed, there is a problem that various lens systems having different input voltages must be prepared.

On the other hand, the user has to select a lens system having an input voltage that matches the voltage value of his or her own power supply facility, and there is a problem that the range of lens selection is narrow. Particularly, in recent years, a lens driven by DC6V has become mainstream, and there is a demand that a lens system for DC6V is newly applied to a conventional DC12V power supply facility and a stable motor rotation speed is secured. Is increasing. However, there is a problem that stable control cannot be obtained if the DC6V lens system is used as it is for the DC12V power supply equipment. Therefore, either a DC12V lens must be used or the equipment side must be changed to DC6V. There is a problem that it must be.

The present invention has been made in view of such circumstances, and even if the voltage value of the power supply equipment is different, one type of lens system can be commonly applied to the television lens motor drive control device. The purpose is to provide.

[0007]

In order to achieve the above object, the present invention rotates at a predetermined rotation speed when a predetermined voltage value is applied and at least one of focus, zoom and iris of a television lens. A motor for driving one, and an on-off switch means for driving the motor,
When the on-off switch means is turned on and selected by the selecting means, the first circuit for directly applying the voltage from the DC power source to the motor and the on-off switch means are turned on, and When selected by the selection means, a second circuit that reduces the voltage from the DC power supply to a predetermined voltage value and applies the voltage to the motor; and, if the voltage value of the DC power supply is the predetermined voltage value, the second circuit. The selecting circuit selects the first circuit, and selects the second circuit when the voltage value is larger than the predetermined voltage value.

[0008]

According to the present invention, when the voltage value of the DC power source is a predetermined voltage value, the first circuit is selected by the selecting means and the voltage of the DC power source is applied to the motor as it is. On the other hand, when the voltage value of the DC power supply is larger than the predetermined voltage value, the selection circuit selects the second circuit,
The voltage supplied from the DC power supply is reduced to a predetermined voltage by the second circuit and applied to the motor. In this way, a constant voltage can be supplied to the motor regardless of the voltage value of the DC power source, and the rotation speed of the motor can be maintained at a certain rotation speed.

Further, since the first and second circuits and the selecting means are provided on the television lens side, a common television lens can be applied to power supply equipment having different voltage values. In particular, the selection means, by configuring a voltage detection circuit using a Zener diode, and a relay that operates in conjunction with the voltage detection circuit, to detect the voltage value of the power supply by the Zener voltage of the Zener diode,
Based on this detection, the relay operates to automatically switch the selecting means.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a television lens motor drive control device according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a circuit diagram showing an example of a control circuit applied to a television lens motor drive control device according to the present invention. This circuit mainly includes a DC power supply 10, an operation switch 12, a rectifier circuit 14, a voltage detection circuit 16, a relay 18,
It is composed of a low voltage circuit 20 and a motor 22,
The motor 22 uses, for example, a gear 23 to take a photographic lens 24.
The focus ring 25 of is driven.

The DC power supply 10 may be DC 12V or DC 6V, for example, and may differ depending on the equipment. In the embodiment shown in FIG.
Regardless of whether a 12V power source or a 6V DC power source is used, the motor 22 has a 6VDC voltage.
This is to ensure stable supply of the voltage. The DC power supply 10 includes positive contact points 12A and 12A 'and negative contact points 12B and 12B', and the operation switch 1 in which two contact pieces 12C and 12D are interlocked and switched.
It is connected to 2.

That is, the operation switch 12 includes the contact piece 12
When C contacts the contact 12A, the contact piece 12D contacts the contact 12A.
When the contact piece 12C comes into contact with B and the contact piece 12C comes into contact with the contact point 12B ', the contact piece 12D comes into contact with the contact point 12A'. In the former case and in the latter case, the polarities of the polarities of the voltage applied to the motor 22 are reversed, so that the forward / reverse rotation of the motor 22 can be switched by switching the operation switch 12. For convenience of description below, the former case will be referred to as the normal rotation of the motor 22 and the latter case will be referred to as the inversion. However, since this circuit is configured by a symmetrical circuit, the operations by the forward rotation / inversion are essentially the same.

The contact of the operation switch 12 is a rectifier circuit 14
And the rectifier circuit 1 connected to the low voltage circuit 20.
The output side of 4 is connected to the voltage detection circuit 16. The rectifier circuit 14 is formed by connecting four diodes in a bridge shape, and plays a role of always flowing a current in the same direction to the voltage detection circuit 16 regardless of the polarity of the operation switch 12.

The voltage detection circuit 16 is composed of a Zener diode D1 and a resistor R1 wired in series.
The cathode end of the Zener diode D1 is connected to the coil 18A of the relay 18, and the anode end of the Zener diode D1 is connected to the base of the transistor Q1.
The other end of the coil 18A of the relay 18 is connected to the collector of the transistor Q1, and the emitter of the transistor Q1 is connected to the anode side of the rectifier circuit 14 together with one end of the resistor R1.

The low voltage circuit 20 includes a transistor Q2
, Q3, diodes D2, D3, resistors R2, R3, R4
, R5. The collector of the transistor Q2 is connected to the extended wire of the contact piece 12C of the switch 12, and the emitter of the transistor Q2 is connected to the motor 22. A diode D2 is provided between the emitter and collector of the transistor Q2, and the cathode side of the diode D2 is connected to the emitter and the anode side is connected to the collector. A resistor R2 is provided between the collector and the base.

A resistor R3 is connected to the base of the transistor Q2, and one end of the resistor R3 is connected to the contact 18B of the relay 18. On the other hand, as shown in the figure, the transistor Q3 is connected to the diode D3, the resistor R4 and the resistor R5 so as to form a symmetrical circuit with the transistor Q2. One end of the resistor R5 is connected to the contact 18C of the relay 18,
When a current flows through the coil 18A of the relay 18, the contact 18
B and 18C are electrically connected.

The operation of the control circuit of the television lens motor drive control device configured as described above will be described. When the operation switch 12 is turned on in the forward direction of the motor 22 (the contact piece 12C contacts 12A and the contact piece 12D contacts 12B).
When they come into contact with each other), the current flows through the rectifier circuit 14 to the voltage detection circuit 16 and also to the low voltage circuit 20.

The output rectified by the rectifying circuit 14 is
When the voltage is higher than the Zener voltage Vz of the Zener diode D1 of the voltage detection circuit 16, the Zener diode D1 is energized, and the current flows into the resistor R1 connected in series with the Zener diode D1. At the same time, the current flows to the base of the transistor Q1. , Turn on the transistor Q1. When the transistor Q1 becomes conductive, the transistor Q1
A current flows through the coil 18A of the relay 18 connected to the collector of the relay 18 and brings the contacts 18B and 18C of the relay 18 into contact with each other.

When the relay 18 operates in this manner, the low voltage circuit 20 is formed with a voltage dividing circuit composed of resistors R2, R3, R4 and R5. That is, the current flowing into the low voltage circuit 20 flows into the resistor R2 and turns on the transistor Q2.
Since 8C is in contact, resistances R2, R3, R4, R5
Since the voltage dividing circuit composed of
A voltage divided by the resistance R2 and the resistances R3, R4 and R5 is applied to 2.

Then, the operation switch 12 is turned off to stop the motor 22. On the other hand, when the output rectified by the rectifier circuit 14 is lower than the Zener voltage Vz of the Zener diode D1, the diode D1 does not conduct and the transistor Q1 remains OFF. At this time, the relay 18 does not operate and the contacts 18B and 18C of the relay 18 remain separated, so that the voltage dividing circuit is not formed in the low voltage circuit 20. That is, the current flowing into the low voltage circuit 20 is the resistance R
2 and turn on the transistor Q2, the motor 22
Is applied to The applied voltage at this time is substantially equal to the voltage of the DC power supply 10.

Since this circuit is a symmetrical circuit, when the operation switch 12 is turned on in the reverse direction of the motor 22, the voltage dividing circuit portion of the low voltage circuit 20 has the resistors R2, R3, Instead of R4, R5, and transistor Q2, it is formed by resistors R4, R5, R2, R3, and transistor Q3, respectively, and the voltage divided by resistor R4 and resistors R5, R2, and R3 is applied to motor 22. Is applied.

The other operations on the circuit are similar to those described above, and the positive and negative polarities of the voltage applied to the motor 22 are merely reversed. Therefore, for example, for a power supply voltage of 12V,
Resistors R2 and R3, R4, R5 (or resistors R4 and R5
, R2, R3), the resistances R2, R3, R4, R5 may be selected so that the voltage divided by R2, R2, R3) is just 6V. The voltage value of the DC power supply 10 is not limited to this and may be another value.

The detection voltage of the voltage detection circuit 16 can be arbitrarily set by selecting the Zener diode D1.
Further, the low voltage value obtained by the voltage division is set to 6 V at the power supply voltage of 12 V in this embodiment, but the voltage dividing resistance R2
It is possible to arbitrarily set it by a combination of ~ R5. In this way, when the voltage supplied from the DC power supply 10 is higher than the predetermined voltage, the voltage is detected by the voltage detection circuit 16 and automatically connected to the low voltage circuit 20 to obtain the predetermined voltage value. Therefore, stable drive control of the focus of the lens or the like becomes possible. Incidentally, the voltage detection circuit 16 of the present embodiment
Instead of the relay 18 and the relay 18, it is possible to provide another selection switch for switching between high voltage and low voltage.

In the above-described embodiment, the case where the number of the voltage detection circuit 16 is one has been described, but not limited to this, a plurality of voltage detection circuits may be provided and a plurality of voltage dividing circuits may be provided. The control circuit may be provided on the television lens side or may be incorporated on the control panel side. In the former case, the rectifier circuit 14, the voltage detection circuit 16, the relay 18, the low-voltage circuit 20, the motor 22 and the like are provided on the TV lens side, while in the latter case, the DC power supply 10 and the operation switch are provided on the controller side. 12, rectifier circuit 14, voltage detection circuit 16, relay 1
8 and a low voltage circuit 20 are provided.

In the above embodiment, the case where the focus ring is driven has been described, but the present invention is not limited to this, and the present invention can be applied to members such as a zoom and an iris.

[0026]

As described above, according to the television lens motor drive control device of the present invention, the first circuit for directly applying the voltage of the DC power supply to the motor and the motor for reducing the voltage of the DC power supply are used. A second circuit to be applied to the first power source and a selection means for selecting the first or second circuit according to the voltage value of the DC power source, and the first circuit when the voltage value of the DC power source is a predetermined voltage value. And the second circuit is selected when the voltage value of the DC power supply is larger than the predetermined voltage value, it is possible to apply a constant voltage to the motor regardless of the power supply voltage value. The rotation speed of the motor can be kept constant. This makes it possible to use a common lens system even for equipment having different power supply voltages.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a TV lens motor drive control device according to the present invention.

[Explanation of symbols]

 10 ... DC power supply 12 ... ON-OFF operation switch 14 ... Rectifier circuit 16 ... Voltage detection circuit 18 ... Relay 20 ... Low voltage circuit 22 ... Motor

Claims (3)

[Claims] 1. When a predetermined voltage value is applied, the TV lens rotates at a predetermined rotation speed to focus, zoom, and
A motor for driving at least one of the iris, an ON-OFF switch means for driving the motor, and a DC power source when the ON-OFF switch means is turned on and selected by the selection means. When the ON / OFF switch means is turned on and selected by the selection means, the voltage from the DC power supply is reduced to a predetermined voltage value, and A second circuit to be applied to the motor, and the first circuit is selected when the voltage value of the DC power source is the predetermined voltage value, and the first circuit is selected when the voltage value is larger than the predetermined voltage value. A motor drive control device for a television lens, comprising: the selecting means for selecting a second circuit. 2. The television lens motor drive control device according to claim 1, wherein the first and second circuits and the selecting means are provided on the television lens side. 3. The television lens motor drive control device according to claim 1, wherein the selection means includes a voltage detection circuit using a Zener diode and a relay that operates in conjunction with the voltage detection circuit. .