Abstract:
The present invention displays the light transmission/reception level, the usable amount of remaining power of a utility, or the like, and by means of viewing the display, a user becomes able to easily make a determination, thus increasing the operability of a television camera device. The television camera device has: a camera head; a camera control unit that controls the camera head; and a cable that connects the camera head and the camera control unit. The camera head is provided with: a means for outputting a utility power source; a return video output means; and a prompt output means. The camera control unit is provided with a detection means that detects the power used by the television camera device. The camera head is provided with an output means that displays the power that the utility power source can output and the power detected by the detection means.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a 371 U.S. National Stage of International Application No. PCT/JP2012/073329, filed Sep. 12, 2012. This application claims priority to Japanese Patent Application No. 2011-246020, filed Nov. 10, 2011. The disclosures of the above applications are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to a television camera device, and in particular, relates to a television camera device that displays the operation state in order to improve the operability of the television camera device. 
     BACKGROUND ART 
     Conventionally, the transmission and/or reception of light are displayed in the front face of a housing of a camera control unit (CCU). However, the camera control unit is usually housed in a rack together with a server and the like and is installed. In the case where the camera control unit is housed in a rack, a user cannot see the front face of the housing of the camera control unit. 
     Accordingly, during operation, even if a problem occurs in a cable for transmission and/or reception of light and causes abnormal transmission and/or reception of light, it is difficult to confirm this state immediately. 
     Moreover, on the camera head side, an electric power is output for a utility. A user cannot easily check the remaining amount of the electric power available for the utility. 
     CITATION LIST 
     Patent Literature 
     
         
         PATENT LITERATURE 1: JP-A-2009-10635 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     Patent Literature 1 discloses a remote monitoring controller, which displays as a video a delay profile waveform of a radio wave digitally modulated by a video signal on the screen of a personal computer in order to alleviate the necessity for the learning level of an operator who controls the direction of a rotating receiving antenna, wherein in an FPU (Field Pickup Unit) reception base station, microwaves transmitted from a transmission station side is received by adjusting the direction of the rotating receiving antenna by operating the personal computer. However, the display of a utility on the camera head side and/or the display of other functions have not conventionally been achieved for the purpose of improving the operability in a television camera device. 
     A television camera device of the present invention is intended to improve the operability of the television camera device by displaying the transmission and/or reception levels of light, the available remaining electric power of a utility, and the like and allowing a user to view the same and thereby easily determine the same. Furthermore, the electric power to be used is limited in accordance with the remaining amount of the utility electric power in order to effectively use the utility electric power that is a finite energy resource. 
     Solution to Problem 
     In order to achieve the above-described purpose, the television camera device of the present invention includes: a detection unit configured to detect the transmission and/or reception of light; a current detection unit configured to constantly detect an electric power when a utility is used; and a display unit configured to display the states thereof, and is intended to improve the operability of a user by using these units. 
     In order to achieve the above-described purpose, according to a first aspect of the present invention, a television camera device includes: a camera head; a camera control unit configured to control the camera head; and a cable connecting the camera control unit and the camera head, wherein the camera head includes a unit configured to output a utility power source, a return video output unit, and a prompt output unit, wherein the camera control unit includes a detection unit configured to detect the electric power used by the television camera device, and wherein the camera head includes an output unit configured to display the electric power detected by the detection unit and an electric power which the utility power source can output. 
     According to a second aspect of the present invention, there is provided the television camera device according to the first aspect of the present invention, wherein an order of priority is assigned to a device to which the utility power source is output, wherein the camera control unit compares a value detected by the detection unit with a predetermined value, and wherein when the detected value is equal to or greater than the predetermined value, the camera control unit restricts, based on the order of priority, a function of the device that uses an output of the utility power source of the camera head. 
     According to a third aspect of the present invention, there is provided the television camera device according to the first aspect of the present invention, wherein the camera control unit displays an amount of usage of electric power of the utility power source of the camera head by using the value detected by the detection unit. 
     Advantageous Effects of Invention 
     According to the present invention, the transmission and/or reception levels of light, an available remaining electric power of a utility, and the like are displayed to allow a user to view the same and thereby easily determine the same, and therefore the operability of the television camera device will improve. 
     Furthermore, in order to effectively use a utility electric power, a device to be connected to the utility electric power is controlled to restrict the function of this device. As a result, an electric power to be used can be limited in accordance with the remaining amount or used amount of the utility electric power. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram illustrating the configuration of one example of a television camera device of the present invention. 
         FIG. 2  is a block diagram illustrating the configuration of one example of a CCU of the television camera device of the present invention. 
         FIG. 3  is a block diagram illustrating the configuration of one example of a camera head of the television camera device of the present invention. 
         FIG. 4  illustrates the actually measured values of relationship between the power consumption of a utility power source and the detection voltages, and an approximation formula, in one example of the television camera device of the present invention. 
         FIG. 5  illustrates the actually measured values of relationship between the consumption current of the camera head and CCU and the detection voltages and an approximation formula, in one example of the television camera device of the present invention. 
         FIG. 6  illustrates one example of the data about the amount of usage of electric power of the utility power source displayed on the display screen of a viewfinder  120 , in one example of the television camera device of the present invention. 
         FIG. 7  illustrates one example of the data about the amount of usage of electric power of the utility power source displayed on the display screen of a viewfinder  120 , in one example of the television camera device of the present invention. 
         FIG. 8  is a view for illustrating display colors in the display example of  FIG. 7 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, one embodiment of the present invention will be described using the accompanying drawings and the like. Note that the following description is for illustrating one embodiment of the present invention, and shall not be construed to limit the scope of the present invention. Accordingly, those skilled in the art could employ embodiments in which each or all of the above-described elements are replaced with the equivalents thereto, and therefore these embodiments are also included in the scope of the present invention. 
     Moreover, in the illustration of each view, a constituent element with the same function is attached with the same reference numeral to avoid the duplication and omit the description thereof as much as possible. 
     First Embodiment 
     A first embodiment of a television camera device of the present invention is illustrated using  FIG. 1  to  FIG. 8 . 
       FIG. 1  is a block diagram illustrating the configuration of one example of the television camera device of the present invention. Reference numeral  100  represents the television camera device of one example of the present invention, reference numeral  110  represents a camera head of the television camera device  100 , reference numeral  120  represents a viewfinder (VF), reference numeral  160  represents a CCU of the television camera device  100 , and reference numeral  180  represents an optical composite cable. Here, the optical composite cable  180  is an optical composite cable for the television camera device and for coupling the camera head  110  and the CCU  160 , carrying out communication between the camera head  110  and the CCU  160 , and carrying out the transmission and/or reception of a video signal (including an audio signal), making an income call, supplying electric power to the camera head, and so on. Moreover, reference numeral  111  represents a utility power source output terminal, to which a utility power source is output, reference numeral  112  represents an SDI output terminal, to which an SDI signal is output, reference numeral  113  represents a return output terminal, to which a return video signal is output, reference numeral  114  represents a prompt output terminal, to which a prompt is output, reference numeral  115  represents a viewfinder output (VF_OUT) terminal, to which a viewfinder output video signal is output, reference numeral  116  represents a control signal input terminal, to which a camera operator inputs a control signal from an operation panel or the like in order to operate the camera head, reference numeral  161  represents an AC power source terminal, to which the electric power of AC 100 V is input, reference numeral  162  represents a control signal input terminal, to which a control signal for controlling the CCU  160  and camera head  110  is input, reference numeral  163  represents a return input terminal for inputting a return video, reference numeral  164  represents a prompt input terminal, to which a prompt video is input, reference numeral  165  represents a video output terminal, to which a video signal is output, reference numeral  166  represents a GENLOCK (GL: Generator Lock) signal input terminal, to which a synchronous signal is input, and reference numerals  181  and  186  represent optical composite cable connection terminals. The television camera device is a high-resolution three-plate type color camera for shooting movies, for example. The control signal input terminal  162  is connected by means of an interface, for example such as RS-485 or RS-422. 
     A staff inputs a control signal to the control signal input terminal  162  using an operation unit. 
     In  FIG. 1 , a case is described, where the camera head  110  is installed inside a television studio  100  and the CCU  160  is installed in a sub-control room. 
     In  FIG. 1 , inside the television studio, the camera head  110  attached with the VF  120  is installed and a camera operator operates the camera head  110  and the VF  120 . Moreover, in the sub-control room, the CCU  160  corresponding to the camera head  110  is installed, and these camera head  110  and CCU  160  are coupled to each other by means of the optical composite cable  180  via the optical composite cable connection terminals  181  and  186 . 
     The camera head  110  is shooting a desired subject inside the television studio. The camera head  110  transmits the shot video to the CCU  160  in the sub-control room via the optical composite cable  180 . 
     The CCU  160  is installed inside the sub-control room, a staff inside the sub-control room controls the camera head  110  via the optical composite cable  180  by operating a non-illustrated operation unit of the CCU  160 . The camera head  110  adjusts the image quality of a video to be shot. Moreover, the CCU  160  supplies an electric power to the camera head  110  inside the television studio via the optical composite cable  180 . 
     For example, a staff inside the sub-control room confirms a video, which is transmitted from the camera head  110  in the television studio, with a non-illustrated monitor. Then, the staff sends an instruction for adjustment to a camera operator or the like in the television studio, via an income call or the like. Moreover, the staff transmits a return video and a prompt signal, which are to be transmitted to the display unit of the VF  120 , via the CCU  160 , the optical composite cable  180 , and the camera head  110 . Furthermore, the staff can also directly control the camera head  110  via the CCU  160  and the optical composite cable  180 . 
     Next, the television camera device of the present invention is further described using  FIG. 2  and  FIG. 3 .  FIG. 2  is a block diagram illustrating the configuration of one example of the CCU  160  of the television camera device  100  of  FIG. 1 .  FIG. 3  is a block diagram illustrating the configuration of one example of the camera head  110  of the television camera device  100  of  FIG. 1 . Reference numeral  3  represents a power source switch (PWR SW), reference numeral  4  represents a transformer, reference numeral  5  represents a relay switch (RLY SW), reference numeral  6  represents a current transformer, reference numerals  7  and  24  each represent an AC/DC converter, reference numeral  8  represents a DC/DC converter, reference numeral  9  represents a rectification circuit, reference numeral  10  represents a relay controller (RLY CNT), reference numeral  11  represents an overcurrent detection circuit, reference numeral  12  represents a no-current detection circuit, reference numeral  13  represents a CPU (Central Processing Unit) that controls each device in the CCU  160 , reference numerals  14  and  23  each represent an video processing unit/control processing unit, reference numeral  15  represents a sync separator that extracts a synchronous signal from the GENLOCK signal input from the GL signal input terminal  166  and outputs the same to the video processing unit/control processing unit  14 , reference numeral  16  represents an ADC (Analog to Digital Converter), reference numerals  17  and  22  each represent an OE (optical to electric)/EO (electric to optical) conversion unit, reference numeral  21  represents an AC/DC converter, reference numeral  25  represents an image pickup device block, reference numeral  26  represents an optical lens system, and reference numeral  27  represents a CPU that controls each device in the camera head  110 . The image pickup device block  25  employs, for example, a CCD (Charge Coupled Device) image pickup device as the image pickup device. 
     In  FIG. 2  and  FIG. 3 , when the power switch  3  of the CCU  160  is turned on from turned off by the operation of a staff or the like, the power source of AC 100 V is supplied to the CCU  160  from the AC power source terminal  161 . The supplied power source is supplied to the transformer  4  and the AC/DC converter  7 . The AC/DC converter  7  converts the supplied AC power source to the DC power source of a predetermined voltage (e.g., 12 V), and supplies the resulting voltage to the DC/DC converter  8 . The DC/DC converter  8  converts the voltage of the supplied DC power source to a predetermined voltage (e.g., 12 V, 5 V, or the like), and supplies the resulting voltage to the corresponding internal devices of the CCU  160 . 
     Moreover, the transformer  4  converts the voltage of the supplied commercial power source of AC 100 V to AC 230 V, and outputs the resulting voltage to the relay switch  5  and the current transformer  6 . 
     The relay switch  5  turns on or off the supplied power source of AC 230 V in accordance with the control of the relay controller  10 , and during turned-on state, the relay switch  5  supplies the electric power of AC 230 V to the optical composite cable connection terminal  186 . The power source supplied to the optical composite cable connection terminal  186  is supplied to the optical composite cable connection terminal  181  of the camera head  110  via the optical composite cable  180 . 
     The current transformer  6  outputs a current, which is shunted for current measurement, to a current rectification circuit  9 . 
     Moreover, in the camera head  110 , the power source (AC 230 V) supplied to the optical composite cable connection terminal  181  from the CCU  160  is supplied to the AC/DC converter  21 . The AC/DC converter  21  converts the supplied power source to the DC power source of a predetermined voltage (e.g., 12 V) and supplies the resulting voltage to the DC/DC converter  24 . The DC/DC converter  24  converts the voltage of the supplied DC power source to a predetermined voltage (e.g., 12 V, 5 V, or the like), and supplies the resulting voltage to the corresponding internal device of the camera head  110  as the internal power source. 
     Furthermore, the power source (AC 230 V) supplied to the optical composite cable connection terminal  181  is output to the utility power source output terminal  111  as a utility power source, which a user (camera operator or the like) can freely use, apart from the power source used as the internal power source of the camera head  110 . 
     The utility power source is often used, for example, as the power source of a device attached to the camera head  110 . The examples of the power source of a device attached to the camera head  110  include the power source of a camera platform having the camera head mounted thereon and panning or tilting, the power source of a floor monitor for monitoring a return video, the power source of a prompter, and the like. 
     Conventionally, the customer side cannot know the usage rate of this utility power source. Accordingly, a user, such as a camera operator, cannot tell how much of the utility power source is currently being used. Then, in one example of the present invention, the data of the amount of usage of electric power of this utility power source is enabled to be output, such as to be displayed on the VF  120 , so that a user, such as a camera operator, operating the camera head  110  can recognize at a glance the amount of usage of electric power of this utility power source. 
     Hereinafter, the example thereof is described using  FIG. 2  and  FIG. 3 . 
     In the camera head  110  of  FIG. 3 , the image pickup device block  25  captures a subject image incident through the optical lens system  26 , converts the captured image to an electric signal, and outputs the converted electric signal to an image processing unit/control signal processing unit  23  as a video signal. The image processing unit/control signal processing unit  23  performs a predetermined image processing on the input video signal and outputs the resulting video signal to the OE/EO conversion unit  22 . Moreover, under the control of the CPU  27 , the image processing unit/control signal processing unit  23  outputs the resulting video signal also to the viewfinder output terminal  115 . The viewfinder  120  is connected to the viewfinder output terminal  115 , so that a camera operator can view the captured video. 
     The OE/EO conversion unit  22  converts to an optical signal the video signal input from the image processing unit/control signal processing unit  23 , and outputs the resulting optical signal to the CCU  160  via the optical composite cable connection terminal  181  and the optical composite cable  180 . 
     In the CCU  160 , the optical composite cable connection terminal  186  receives the video signal sent from the camera head  110 , and outputs the same to the OE/EO conversion unit  17 . The OE/EO conversion unit  17  converts to an optical signal the video signal input from the optical composite cable connection terminal  186 , and outputs the resulting optical signal to the image processing unit/control signal processing unit  14 . The image processing unit/control signal processing unit  14  performs a predetermined image processing on the input video signal, and outputs the resulting video signal to the video output terminal  165 . A monitor is connected to the video output terminal  165 , so that the output video can be viewed. 
     Moreover, in the CCU  160 , the image processing unit/control signal processing unit  14  outputs a video signal, such as a video which another television camera device captured, input from the outside (not illustrated) or the video signal of a video, which the camera head  110  captured and on which the image processing unit/control signal processing unit  14  performed the image processing, to the camera head  110  via the OE/EO conversion unit  17 , the optical composite cable connection terminal  186 , and the optical composite cable  180 . 
     In the camera head  110 , the image processing unit/control signal processing unit  23  performs image processing on the above-described video signal, which is sent via the optical composite cable connection terminal  181  and the OE/EO conversion unit  22  from the CCU  160 , and outputs the resulting video signal to the return output terminal  113 . To the return output terminal  113  is connected, for example, a floor monitor, where a return video is displayed. 
     Similarly, a prompt signal output from the CCU  160  is output to the prompt output terminal  114  from the image processing unit/control signal processing unit  23  of the camera head  110 . To the prompt output terminal  114  is connected a prompter, where a prompt from the prompt output terminal  114  is displayed. 
     In the CCU  160  of  FIG. 2 , the output current of the transformer  4  is shunted using the current transformer  6 , and the current rectification circuit  9  rectifies the input voltage and outputs a value of the rectified voltage to the overcurrent detection circuit  11  and the no-current detection circuit  12 . The overcurrent detection circuit  11 , if the input rectified-voltage is equal to or greater than a predetermined voltage, determines as overcurrent (shorting of a cable), and outputs a turn-off signal to the relay controller  10 . Moreover, the no-current detection circuit  12 , if the input rectified-voltage is less than a predetermined voltage, determines as “no current” (opening of a cable), and outputs a turn-off signal to the relay controller  10 . 
     When the turn-off signal is input from at least either of the overcurrent detection circuit  11  or the no-current detection circuit  12 , the relay controller  10  turns off (cuts off) the relay switch  5  to protect the power source. 
     As described above, in the present invention, a current being supplied to the camera head  110  is monitored, and if this current is equal to or greater than a predetermined voltage, it is determined as overcurrent (shorting of a cable), while if this current is less than a predetermined voltage, it is determined as “no current” (opening of a cable), thereby protecting the power source. 
     The rectification circuit  9  outputs this voltage value also to the ADC  16 . Similarly, the overcurrent detection circuit  11  outputs the result of determination of whether or not the current being supplied to the camera head  110  is a overcurrent also to the ADC  16 , and the no-current detection circuit  12  outputs the result of determination of whether or not this current is “zero” also to the ADC  16 . 
     The ADC  16  converts the input voltage value and the determination result thereof to a digital value and outputs this digital value to the video processing unit/control processing unit  14 . The video processing unit/control processing unit  14  outputs this digital value to the CPU  13 . 
     For example, using the value read by the ADC  16 , display data of each of the current power consumption of the camera head  110  and CCU  160  and the current amount of usage of electric power of the utility power source is output as a video output. 
     For example, when the detection voltage is X [unit: V], the amount of usage of electric power of the utility power source Y [unit: VA] is expressed as Formula (1) below from the actually measured results (see  FIG. 4  and  FIG. 5 ).
 
 Y= 89.681 X− 45.406  Formula (1)
 
     The current usage value when the maximum available value is set to 191 VA is displayed on a screen. ( FIGS. 1 and 3 ) 
     The CPU  13  determines whether or not the voltage value input from the video processing unit/control processing unit  14  is an error (overcurrent or no current), and if it is an error, the CPU  13  controls the video processing unit/control processing unit  14  to display the error via the video output terminal  165 . Moreover, preferably, even when it is not an error, the CPU  13  controls the video processing unit/control processing unit  14  to display this fact via the video output terminal  165 . 
     Furthermore, the CPU  13  controls the video processing unit/control processing unit  14  to output the display data about the amount of usage of electric power of the utility power source to the OE/EO conversion unit  17  from the camera head  110 . 
     The OE/EO conversion unit  17  converts the input display data to an optical signal and outputs this optical signal to the optical composite cable connection terminal  181  of the camera head  110  via the optical composite cable connection terminal  186  and the optical composite cable  180 . 
     The optical composite cable connection terminal  181  of the camera head  110  outputs the input display data to the OE/EO conversion unit  22 . The OE/EO conversion unit  22  converts the input display data to an electric signal and outputs this electric signal to the video processing unit/control processing unit  23 . 
     The video processing unit/control processing unit  23  outputs the input display data to the viewfinder output terminal  115 . As a result, the data about the amount of usage of electric power of the utility power source is displayed on the viewfinder  120  connected to the viewfinder output terminal  115 . 
       FIG. 6  illustrates one example of the data about the amount of usage of electric power of the utility power source displayed on the display screen of the viewfinder  120 . 
     In a display  600  displayed on the display screen of the viewfinder  120 , a bar graph  610  indicative of the whole available electric power, the bar graph  610  comprising an allowable region  611  indicative of a predetermined allowable power range, a warning region  612  indicative of a predetermined warning power range, and a limiting area  613  indicative of a predetermined limiting power range, is first displayed. In the bar graph  610 , there are displayed a text display  621  of the smallest power value, a text display  622  of the current electric power, an indicator graphic  620  indicative of the position of the current electric power, a text display  623  indicating that an electric power value equal to or greater than this point is in the warning power range, a text display  624  indicating that an electric power value equal to or greater than this point is in the limiting power range, and a text display  625  indicative of the maximum power value. 
       FIG. 7  illustrates one example of the data about the amount of usage of electric power of the utility power source displayed on the display screen of the viewfinder  120 . 
     In the display  700  displayed on the display screen of the viewfinder  120 , the current power value of the utility power source is displayed as “111 VA”, as a display  702  of “UTILITY PWR”, as illustrated in the display  600  of  FIG. 6 . Moreover, other than this, the followings are displayed. 
     First, in a display  701  of “OPT LEVEL”, the reception level of each of the camera head  110  and the CCU  160  is displayed. 
     For example, the reception level of the camera head  110  is illustrated as a bar graph  710 , and the reception level of the CCU  160  is illustrated as a bar graph  720 . Here, in the bar graphs  710  and  720 , the whole bar corresponds to the maximum reception level, cross-hatched regions  711  and  721  each indicate the reception level. 
     The display colors of the reception levels  711  and  721  are, for example as illustrated in  FIG. 8 , displayed as follows: (a) a reception level R indicates −3 dBm≧R&gt;−8 dBm (the fill color of a region  81  is green indicative of safety), (b) the reception level indicates −8 dBm≧R&gt;−11 dBm (the fill color of a region  82  is green indicative of safety), (c) the reception level indicates −11 dBm≧R&gt;−14 dBm (the fill color of a region  83  is yellow indicative of warning), and (d) the reception level indicates −14 dBm≧R (the fill color of a region  84  is red indicative of danger). 
     Next, a display  703  of “Cable Condition OK” is displayed. Here, if the optical composite cable  180  is determined as being connected, then “OK” is displayed, if determined as being open, then “OPEN” is displayed, and if determined as being shorted, then “SHORT” is displayed. 
     Moreover, a display  704  of “Cable Length 100 m” is displayed. For the calculation of this length, data for measurement is input to the user area of a transmission packet and this packed is transmitted and received, thereby calculating the length. The calculated length is displayed, for example, in meter as “100 m” or “50 m” for example. 
     Moreover, a display  705  of “CCU PWR COND” is displayed. The display  705  indicates all the electric power which the CCU  160  is using as a total. For example, a total (56 W+35 W+111 W=202 W) of 56 W consumed by the CCU  160 , 35 W consumed by the camera head  110 , and 111 VA (111 W for convenience in this example) of the display  702  of “UTILITY PWR” described above is displayed. 
     Moreover, a display  706  of “GL ON/OFF” is displayed. The display  706  indicates whether GEN LOCK is in an on-state or an off-state, and in the case of the on-state, “ON” is displayed, while in the case of the off-state, “OFF” is displayed. Moreover, a display  707  of “GL SOURCE B.B.” is displayed. The display  707  indicates what the source of the GENLOCK (GL) signal is based on, and in the case of from B.B. (Black Burst), “B.B.” is displayed, in the case of from Tri-Sync, “Tri-Sync” is displayed, or in the case where an external synchronous signal is not input or the GENLOCK (GL) signal is not synchronized, “None” is displayed. 
     As described above, with the television camera device of the first embodiment of the present invention, a user can visually check the margin of the used power of a utility device, and therefore can easily determine the same. 
     Second Embodiment 
     Furthermore, a second embodiment of the present invention is described with reference to  FIG. 1  to  FIG. 5 . The second embodiment of the present invention, in addition to the first embodiment, is capable of controlling so that the level of priority is assigned to a device using the utility power source, the amount of usage of electric power of the utility power source is monitored, and the electric power supplied to a device or the function of the device is restricted in accordance with the amount of usage of electric power. That is, in order to effectively use a utility electric power, a device to be connected is controlled and the function of the device to be connected is restricted. As a result, electric power to be used can be limited in accordance with the remaining amount or used amount of the utility electric power. 
     In the second embodiment, as the order of priority, the first priority is assigned to a camera platform, and the second priority is assigned to the return output and the prompter output. 
     As with the first embodiment, the CCU  160  monitors the current supplied to the camera head  110 . For example, the CPU  13  detects, based on a digital value input from the video processing unit/control processing unit  14 , the current power consumption of the camera head  110  and CCU  160 , and the current amount of usage of electric power of the utility power source. 
     Then, when the used power of the utility power source exceeds a predetermined value (e.g., the used power is in the limiting power range or in the warning power range), the CPU  13 , in order to preferentially supply the electric power to be supplied to the camera platform, controls the video processing unit/control processing unit  23  to set the brightness level of a video output to the return output terminal  113  and the brightness level of a prompter output to the prompt output terminal  114  to the minimum level, respectively. 
     For example, the CPU  13  superimposes the above-described control signal on a BB (Black Burst) signal, and outputs the resulting signal from the video processing unit/control processing unit  14 , and outputs the same to the CPU  27  via the OE/EO conversion unit  17 , the optical composite cable connection terminal  186 , the optical composite cable  180 , the optical composite cable connection terminal  181 , and the OE/EO conversion unit  22 . The CPU  27  controls, based on the input control signal, the video processing unit/control processing unit  23  to set the brightness level of a video, which is output from the video processing unit/control processing unit  23  and output to the return output terminal  113 , and the brightness level of a prompter output to the prompt output terminal  114  to the minimum level, respectively. 
     According to the second embodiment, the television camera device detects the current amount of usage of electric power of the utility power source, and when the used power is in the limiting power range or in the warning power range, the television camera device automatically lowers the brightness level of a video signal output to a device (e.g., the floor monitor connected to the return output terminal  113  and/or the prompter connected to the prompt output terminal  114 ) with a lower priority. 
     As a result, the used power of the floor monitor or the prompter is suppressed and the used power decreases, and therefore a total amount of usage of electric power of the utility power source can be suppressed, so that the utility power source will never be disconnected due to over power. Accordingly, the television camera device can be efficiently used without stopping the function of a device (e.g., camera platform) minimally required for operation (with a higher priority) of the television camera device. 
     Note that, the automatically controlled content may be displayed in text in the VF  120 . 
     Note that, in the first embodiment or the second embodiment, preferably, the CPU  13  may output, to the video processing unit/control processing unit  23  or the CPU  27  of the camera head  110 , a control signal to output audio and thereby cause to output a warning in voice from the camera head  110 . As a result, in addition to the effect of the first embodiment or the second embodiment, a camera operator can know also by voice (auditory sense) that the remaining available electric power is low and thus the television camera device can be efficiently operated without stopping the function of a device minimally required for operation of the television camera device. 
     Note that, in the above-described first embodiment and second embodiment, the CCU and the camera head are connected to each other with an optical composite cable, but a multicore coaxial cable capable of signal transmission of time division multiplex or the like and of supplying electric power may be used in place of the optical composite cable and the OE/EO conversion unit. 
     INDUSTRIAL APPLICABILITY 
     The present invention can be used not only for the television camera device that uses an optical composite cable and multicore coaxial cable for transmission as the digital video signal multiplex transmission method, but also used for the method for displaying the state of the used power of a device that uses a cable capable of transmitting a wide range of signals and of supplying electric power. 
     REFERENCE SIGNS LIST 
     
         
           3 : power source switch (PWR SW) 
           4 : transformer 
           5 : relay switch (RLY SW) 
           6 : current transformer 
           7 ,  21 : AC/DC converter 
           8 ,  24 : DC/DC converter 
           9 : rectification circuit 
           10 : relay controller (RLY_CONT) 
           11 : overcurrent detection circuit 
           12 : no-current detection circuit 
           13 ,  27 : CPU (central processing unit) 
           14 ,  23 : video processing unit/control processing unit 
           15 : sync separator 
           16 : ADC (analog to digital converter) 
           17 ,  22 : OE (optical to electric)/EO (electric to optical) conversion unit 
           25 : image pickup device block 
           26 : optical lens system 
           100 : television camera device 
           110 : camera head 
           111 : utility power source output terminal 
           112 : SDI output terminal 
           113 : return output terminal 
           114 : prompt output terminal 
           115 : viewfinder output (VF_OUT) terminal 
           116 : control signal input terminal 
           120 : viewfinder (VF) 
           160 : CCU 
           161 : AC power source terminal 
           162 : control signal input terminal 
           163 : return input terminal 
           164 : prompt input terminal 
           165 : video output terminal 
           166 : GL signal input terminal 
           180 : optical composite cable 
           181 ,  186 : optical composite cable connection terminal 
           600 : display 
           610 ,  611 ,  612 ,  613 : region 
           621 ,  622 ,  623 ,  624 ,  625 : text display