JP3393438B2 - TV camera device - Google Patents

Description

[0001] The present invention will be described in the following order. INDUSTRIAL APPLICATIONS Outline of the Invention Prior Art (FIG. 3) Problems to be Solved by the Invention (FIG. 3) Means for Solving the Problems (FIGS. 1 and 2) Operation (FIGS. 1 and 2) BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television camera apparatus, and more particularly to a television camera apparatus in which an image pickup section and a signal processing section are separated from each other and connected by a connection cable. It is suitable. Conventionally, as a television camera device, for example, in a video camera device 1, as shown in FIG. 3, a camera head portion 2 including a photographic lens and a CCD (charge coupled device) image sensor, and this camera head portion 2 is connected to a video tape recorder unit 3 for performing predetermined signal processing on the output signal of the second unit and recording the result on a magnetic tape by a connection cable 4 having a plurality of channels (Japanese Patent Application No. 2-60282). In the case of such a video camera device 1, the video tape recorder section 3 generally includes a camera control section, and the iris, focus, and the like of the camera head section 2 are also transmitted from the video tape recorder section 3 through a connection cable 4. The zoom ratio and the like can be controlled. Accordingly, if, for example, only the camera head 2 is mounted on a tripod head, and the camera head 2 is controlled by a video tape recorder 3 which is connected by a connection cable 4 and is located at a remote place, In order to quickly perceive the sign of the photographer or the like, it is possible to freely record the ecology of a small animal or the like that is difficult to photograph with an integrated video camera device. However, in the video camera device 1 having such a configuration, for example, the camera head 2
Is controlled by a DC voltage, and when the ground level of the iris motor of the camera head unit 2 and the ground level of the chassis are separated, the voltage drops to the control signal due to the impedance of the ground level of the iris motor of the camera head unit 2. There was a problem that occurred. In practice, this voltage drop occurs at about 1 [V] per 100 [m] of the length of the connection cable 4, and eventually the voltage of the control signal sent from the video tape recorder unit 3 is reduced by the length of the connection cable 4. Therefore, the iris of the camera head 2 cannot be accurately controlled, and a malfunction such as hunting may occur. SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and aims to propose a television camera device which can always optimally control an imaging unit from a signal processing unit without being affected by the length of a connection cable. It is. According to the present invention, there is provided an image pickup device and a predetermined controlled unit.
And a signal processing unit 3 for performing predetermined signal processing on an output signal of the imaging unit 2 are separated from each other by a connection cable 4 having a plurality of channels C1, C2, C3, C4, and C5. The control signal S1 and the reference level signal GL (GV1) corresponding to the ground level of the controlled unit 11 are transmitted from the signal processing unit 3 to the imaging unit 2 via different channels C4 and C5 of the connection cable 4 which are connected. At the same time, the control signal S1 is sent from the imaging unit 2 to the signal processing unit 3.
Is transmitted, and the signal processing unit 3 controls the controlled unit 11 of the imaging unit 2 based on the control signal S1. In the television camera device 10, the voltage of the control signal S1 is supplied to the imaging unit 2. And the reference level signal GL
The voltage of (GV1) is added using the ground levels GV1 and GV2 of the chassis of the imaging unit 2 and the signal processing unit 3 as reference potentials, and the obtained addition signal is supplied to the controlled unit 11 as a control voltage V10 and the control voltage The voltage of the reference level signal GL (GV1) is converted from the response voltage V11 output from the controlled unit 11 in response to V10 to the imaging unit 2 and the signal processing unit 3
The compensation means 13 for subtracting the ground levels GV1 and GV2 of the chassis as reference potentials and transmitting the resulting subtracted signal as a response signal S2 is provided. The compensation means 13 provided in the imaging section 2
The voltage of the control signal S1 and the voltage of the reference level signal GL (GV1) sent from the signal processing unit 3 are added using the ground levels GV1 and GV2 of the chassis of the imaging unit 2 and the signal processing unit 3 as reference potentials, and the control voltage V10 As imaging unit 2
And the control voltage V1
Response voltage V1 output from the controlled unit 11 in response to
1 to the voltage of the reference level signal GL (GV1)
And ground levels GV1 and G of the chassis of the signal processing unit 3
The signal is supplied to the signal processing unit 3 as a response signal S2 obtained by subtracting V2 as a reference potential. Thus, the voltage drop generated in the control signal S1 and the response signal S2 according to the length of the connection cable 4 is converted to the ground level GV1 of the chassis of the imaging unit 2 and the signal processing unit 3.
And a reference level signal GL (GV2 with GV2 as a reference potential).
Compensation can be performed according to the voltage of 1), and the controlled unit 11 of the imaging unit 2 is controlled in accordance with the control signal S1 sent from the signal processing unit 2 without being affected by the length of the connection cable 4. obtain. An embodiment of the present invention will be described below in detail with reference to the drawings. In FIG. 1, in which parts corresponding to those in FIG. 3 are assigned the same reference numerals, reference numeral 10 denotes a video camera apparatus as a whole according to the present invention, in which a camera head 2 and a video tape recorder 3 are connected by a connection cable 4. ing. In this embodiment, the connection cable 4 is composed of five channel lines, and the power supply VB is connected from the video tape recorder unit 3 to the iris servomotor 11 of the camera head unit 2 through the first channel line C1. At the same time, the ground level of the servo motor 11 (hereinafter referred to as the lens ground level GL) is changed through the second channel line C2 to the ground level of the chassis of the video tape recorder unit 3 (hereinafter referred to as the first chassis). (Referred to as a ground level GV1). The ground level of the chassis of the camera head unit 2 (hereinafter referred to as a second chassis ground level GV2) is changed to the first chassis ground level GV1 of the video tape recorder unit 3 through the third channel line C3. It is connected. In addition, the iris control signal S1 is supplied from the camera control circuit 12 of the video tape recorder section 3 to the compensation circuit 13 of the camera head section 2 through the fourth channel line C4. The control voltage V10 supplied via the
1 is controlled. The response voltage V11 obtained from the servo motor 11 is sent to the compensation circuit 13 and sent to the camera control circuit 12 as a response signal S2 through the fifth channel line C5. In FIG. 1, the resistance of the first channel line C1 to which the power supply VB is supplied is denoted by RS, and the resistance of the second channel line C2 to which the lens ground level GL is connected is denoted by RG. In this manner, the lens ground level GL and the second chassis ground level GV on the camera head 2 side.
When the camera head 2 is separated, when the automatic iris control circuit (not shown) is driven by the camera head unit 2, the servo motor 11 operates to cause a current to flow. As a result, the lens ground level GL due to the resistance RG of the second channel line C2 is reduced. The voltage rise acts on the automatic iris control circuit. When the camera control circuit 12 of the video tape recorder unit 3 controls the camera head unit 2 by transmitting an iris control signal S1 having a voltage V0 to the camera head unit 2, the camera head unit 2 actually has the following equation: An iris control signal S1 that is obtained by dropping the voltage V0 by the voltage VG with respect to the voltage V0 is supplied. In the equation (1), the voltage VG corresponds to the voltage rise of the lens ground level GL due to the resistance RG of the second channel line C2 according to the length of the connection cable 4. In the case of this embodiment, Compensation circuit 1 for camera head 2
3, the first and second chassis ground levels GV1
And GV2 as a reference. That is, as shown in FIG. 2, the compensating circuit 13 is composed of an adding circuit 15 and a subtracting circuit 16 each of which is an operational amplifier and has negative feedback resistors R10 and R20. In practice, the non-inverting input terminal of the adding circuit 15 has
The iris control signal S1 supplied through the fourth channel line C4 is input via the resistor R11, and the lens ground level GL is set through the resistor R11 through the second channel line C2.
12 and a first and second chassis ground level G through a third channel line C3 to an inverting input terminal.
V1 and GV2 are input via the resistor R13. Thus, the adder circuit 15 adds the iris control signal S1 and the lens ground level GL using the first and second chassis ground levels GV1 and GV2 as reference potentials, and the resultant addition signal is used as the control voltage V10. It is supplied to the servo motor 11. Thus, the servo motor 11 can be controlled by compensating for the voltage fluctuation of the lens ground level GL included in the iris control signal S1. The response voltage V11 obtained by controlling the servomotor 11 by the control voltage V10 is input to the non-inverting input terminal of the subtraction circuit 16 via a resistor R21, and the third channel line C3 Through the first and second
Ground levels GV1 and GV2 are input via a resistor R22, and a second channel line C
2, the lens ground level GL is input via the resistor R23. Thus, the subtraction circuit 16 subtracts the lens ground level GL from the response voltage V11 using the first and second chassis ground levels GV1 and GV2 as reference potentials, and uses the resulting subtraction signal as the response signal S2. The video signal is transmitted to the camera control circuit 12 of the video tape recorder section 3 through the channel line C5 of FIG. Thus, the response signal S2 obtained by compensating for the voltage fluctuation of the lens ground level GL added to the control voltage V10 can be sent to the camera control circuit 12. Thus, in the case of this embodiment, the voltage drop generated in the iris control signal S1 and the response signal S2 according to the length of the connection cable 4 is compensated using the chassis ground levels GV1 and GV2 as reference potentials. With this arrangement, the camera head unit 2 always receives the iris control signal S1 sent from the camera control circuit 12 of the video tape recorder unit 3 without being affected by the length of the connection cable.
Can be optimally controlled. According to the above configuration, the compensation circuit 13 provided in the camera head 2 adds the iris control signal S2 and the lens ground level GL and supplies the result as a control voltage V10 to the iris servomotor 11. By subtracting the lens ground level GL from the resulting response voltage V11 and supplying it to the camera control circuit 12 as a response signal S2, a voltage drop occurring in the iris control signal S2 due to the length of the connection cable 4 is reduced. , Can be compensated according to the voltage fluctuation of the lens ground level GL. Thus, the camera control circuit 1 of the video tape recorder unit 3 is always unaffected by the length of the connection cable 4.
A video camera device 10 capable of optimally controlling the iris servomotor 11 of the camera head unit 2 according to the iris control signal S2 sent from the camera head 2 can be realized. In the above-described embodiment, a connection cable including five channel wires is used.
In addition, a plurality of channel lines such as a channel line for transmitting a video signal and an audio signal collected by the camera head unit and a channel line for controlling a focus and a zoom ratio may be included. In the above embodiment, the case where the iris servomotor of the camera head section is controlled from the camera control circuit of the video tape recorder section as a controlled section has been described. The present invention can be applied to a device that is controlled by a control signal including a DC voltage such as a zoom ratio and the like. In the case of controlling the focus and zoom ratio, if the focus control signal and zoom ratio control signal supplied through the channel line of the connection cable are compensated by the compensation circuit, the same effect as in the above-described embodiment can be obtained. Can be realized. Further, in the above embodiment, the case where the present invention is applied to a video camera apparatus has been described. However, the present invention is not limited to this, and only a video signal processing unit is used as a signal processing unit instead of a video tape recorder unit. Which is suitable for application to a television camera device configured to transmit a video signal captured by an imaging unit. As described above, according to the present invention, the voltage of the control signal and the voltage of the reference level signal are adjusted by the compensation means provided in the imaging unit to the ground level of the chassis of the imaging unit and the signal processing unit. Is added as a reference potential and supplied as a control voltage to the controlled part of the imaging unit, and the voltage of the reference level signal is subtracted from the resulting response voltage using the ground level of the chassis of the imaging unit and the signal processing unit as the reference potential. By supplying the response signal as a response signal to the signal processing unit, a voltage drop generated in the control signal and the response signal according to the length of the connection cable can be compensated according to the voltage of the reference level signal. Thus, it is possible to realize a television camera device capable of always optimally controlling the controlled section of the image pickup section in accordance with the control signal sent from the signal processing section without being affected by the length of the connection cable.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing one embodiment of a video camera device according to the present invention. FIG. 2 is a connection diagram showing a compensation circuit of the video camera device of FIG. FIG. 3 is a schematic perspective view showing the appearance of the video camera device. [Description of Signs] 1, 10 video camera device, 2 camera head section, 3 video tape recorder section, 4 connection cable, 11 iris servomotor, 12 camera control circuit, 13 ...... Compensation circuit.

Claims (1)

(1) An image pickup section provided with an image pickup device and a predetermined controlled section, and a signal processing section for performing predetermined signal processing on an output signal of the image pickup section are separated from each other. Are connected by a connection cable having a plurality of channels, and control signals are sent from the signal processing unit to the imaging unit via different channels of the connection cable according to a control signal and a ground level of the controlled unit.
A reference signal is transmitted from the imaging unit, a response signal to the control signal is transmitted from the imaging unit to the signal processing unit, and the controlled unit of the imaging unit is controlled by the signal processing unit based on the control signal. In the television camera device configured as described above, a voltage of the control signal and a voltage of the reference level signal are supplied to the imaging unit by a chassis of the imaging unit and the signal processing unit.
Is added as a reference potential, and the obtained addition signal is supplied to the controlled part as a control voltage, and the reference level signal is output from the response voltage output from the controlled part in response to the control voltage. Voltage of the above imaging unit and
A television camera device comprising a compensating means for subtracting a ground level of a chassis of a signal processing unit as a reference potential and transmitting an obtained subtracted signal as the response signal.