JP2018148538A - Camera device and camera system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera device comprising a power source with high reliability.SOLUTION: A camera device 20 comprises: electric power supply means 30 which is optically connected with a light source unit 13 of a center device 10 through a transmission path 2; imaging means 22 of performing imaging by electric power supplied from the electric power supply means 30; and transmission means 23 of transmitting an imaging signal acquired by the imaging means 22 to the center device 10 through a transmission path 3. The electric power supply means 30 includes: an input part 31 to which external electric power is supplied from an AC power 21; a light reception part 32 that converts light transmitted from the center device 10 through the transmission path 2 into electric power; and a control part 37 that controls the imaging means 22 on the basis of the presence of the supply of the external electric power. The control part 37 performs control so as to image a total monitoring target region with a moving image by the external electric power from the input part 31 when the external electric power is supplied, and image one part of the monitoring target region with the moving image in a low power consumption mode by optical electric power supply source from the light reception part 32 when the external electric power is not supplied.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a camera device and a camera system that capture a moving image or a still image of a subject, and more particularly to a camera device that monitors a monitoring target region by capturing a train track such as a track and a camera system including the camera device.

  Conventionally, in order to monitor a disaster risk location, etc., a terminal device of a disaster prevention information system is installed to monitor weather information such as rainfall, water level and wind speed, and a surveillance camera is installed at a monitoring target location. Various numerical data acquired by the terminal device are reinforced by using an image of the monitoring target area captured by the monitoring camera. Such locations to be monitored are not only in the vicinity of mountains, rivers and dams, but also in areas related to transportation such as railways. Especially in the railway field, it is important to ensure safe and stable train operation. Therefore, a monitoring camera is installed beside the track to constantly detect changes or abnormalities on the train track.

  However, it may be difficult to supply power to the monitoring camera locally depending on the installation location of the monitoring camera, such as where the monitoring target is a remote location. In order to solve this problem, for example, an optical power supply type camera device capable of supplying electric power via an optical fiber is provided, and an image of a monitoring target region is imaged by light / power conversion in the optical power supply type camera device. An optical power supply type camera system that can perform the above has been proposed (Patent Document 1).

  In the railway field, monitoring cameras such as railroad tracks, railroad crossings, etc. are installed, and by analyzing the image / video data of the monitoring area acquired by the monitoring camera, the occurrence of abnormalities in the monitoring area is detected. Detection is generally performed (Patent Documents 2 and 3).

Japanese Patent No. 5765583 JP 2014-24400 A Japanese Patent No. 5096959

  However, in the system of Patent Document 1 described above, power is stored in the power storage unit after the completion of image output associated with the previous imaging operation, and the imaging operation is performed again when the voltage of the power storage unit reaches a predetermined voltage. The imaging operation cannot be performed from the completion of the image output until the next imaging operation is resumed, and it cannot be said that the monitoring target area is sufficiently monitored.

  Further, in the systems of Patent Documents 2 and 3, since the surveillance camera is normally driven by the power supply from the lamps installed on the train track, the imaging operation of the surveillance camera when the power supply is stopped for some reason Can not do. Therefore, in the event of a power outage during a disaster, the monitored area cannot be monitored and obstacles on the train track cannot be grasped, which may hinder train operation and is safe and stable. There are concerns about securing train operations.

  As a countermeasure against such a power failure, a method is used in which an uninterruptible power supply is attached to the surveillance camera and the power supply from the power storage means is switched when the power supply from the outside is stopped. There must be regular inspections and replacements in preparation for unexpected disasters and power outages. In addition, the location where the surveillance camera is installed may be a place where there are no people at all times or a place where it is difficult for people to approach, and it may be difficult to inspect or replace the power storage means. Furthermore, a configuration in which a solar panel is attached to the surveillance camera is conceivable, but it is difficult to continuously monitor the monitoring target area because solar power generation is greatly affected by the amount of solar radiation and lacks power stability and power sustainability. .

  The present invention has been made in view of the above, and an object thereof is to provide a camera device and a camera system including a highly reliable power source.

  In order to achieve the above object, a camera device according to the present invention includes a power supply unit including an input unit to which external power is supplied and a light receiving unit that converts light transmitted from the center device to power through a transmission path. Means, imaging means for imaging with power supplied from the power supply means, transmission means for transmitting an imaging signal obtained by the imaging means to the center device via the transmission path, and supply of the external power A control unit that controls the imaging unit based on the presence or absence of the image, and the control unit images the entire monitoring target area with a moving image by the external power from the input unit when the external power is supplied. And when the said external electric power is not supplied, it controls to image the said monitoring object area | region in the low power consumption mode with the electric power from the said light-receiving part.

  The low power consumption mode is a mode in which a part of the monitoring target area is controlled to be captured as a moving image.

  The power supply unit further includes a merging unit that merges the electric power from the input unit and the electric power from the light receiving unit, and determines whether the external power is supplied based on the voltage of the merging unit.

  When the voltage of the junction unit is higher than a first predetermined voltage, the control unit images the monitoring target area with external power from the input unit, and the voltage of the junction unit is equal to or lower than the first predetermined voltage. And when exceeding the 2nd predetermined voltage which is a value smaller than the said 1st predetermined voltage, it controls so that the said monitoring object area | region may be imaged with the electric power from the said light-receiving part.

  In order to achieve the above object, a camera system according to the present invention is a camera system including a center device and a camera device connected to the center device via a transmission path, and the camera device has an external power supply. A power supply unit including an input unit to which power is supplied, a light receiving unit that converts light transmitted from the center device through the transmission path into electric power, and an imaging unit that captures an image with the electric power supplied from the power supply unit And a transmission unit that transmits an imaging signal obtained by the imaging unit to the center device via the transmission path, and a monitoring target region by external power from the input unit when the external power is input. And a control unit for controlling the imaging of the monitoring target area in the low power consumption mode by the power from the light receiving unit when no external power is input. The center device, characterized by comprising: a light source unit for sending light to the camera device via the transmission path, and a receiving unit that receives the image signal transmitted from the camera device.

  ADVANTAGE OF THE INVENTION According to this invention, a camera apparatus and camera system provided with a reliable power supply are realizable.

It is a figure which shows schematically an example of a structure of the camera system which concerns on embodiment of this invention. It is a block diagram which shows the structure of the camera apparatus in FIG. It is a block diagram which shows the detailed structure of the electric power feeding means in FIG. It is a figure which shows an example at the time of applying the camera system of FIG. 1 to a train track. It is a flowchart which shows the imaging process performed by the control part of FIG. (A) is a figure which shows an example of the moving image imaged at step S14 of FIG. 5, (b) is a figure which shows an example of the moving image imaged at step S17 of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Configuration of Camera System and Camera Device]
FIG. 1 is a diagram schematically showing an example of the configuration of a camera system according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of the camera device in FIG.

  The camera system 1 according to this embodiment includes a center device 10 and a camera device 20 connected to the center device 10 via transmission paths 2 and 3. The center device 10 is connected to a DC power source 11 and a display unit 12, and the camera device 20 is connected to an AC power source 21 such as a lamp power source. In this camera system 1, light for power supply is transmitted from the center device 10, which is an optical power feeder, to the camera device 20. The camera device 20 captures an image by either or both of power supply by photoelectric conversion of light from the center device 10 and power supply from the AC power supply 21, and the image captured by the camera device 20 is transferred to the center device 10. The moving image or the still image is displayed on the display unit 12 on the center device 10 side. Note that the center device 10 may be connected to an AC power source, and the camera device 20 may be connected to a DC power source.

  The transmission path 2 is composed of, for example, an optical fiber cable having an optical fiber for supplying power, and the transmission path 3 is composed of an optical fiber cable having an optical fiber for transmitting image signals. These optical fibers are, for example, single mode fibers. (SMF). In FIG. 1, the transmission lines 2 and 3 are shown separately. However, these transmission lines are constituted by one SMF or the like, and WDM couplers or the like for multiplexing and demultiplexing light of different wavelengths are provided at both ends. You may connect with each input-output terminal of the center apparatus 10 and the camera apparatus 20. FIG.

  The center device 10 includes a light source unit 13 that transmits light to the camera device 20 via the transmission path 2 and a light receiving unit 14 (receiving unit) that receives an imaging signal transmitted from the camera device 20. The center device 10 can be installed in a place where people can easily go in and out, for example, in a management room of various facilities, and secures a highly reliable power source, for example, an emergency power source such as an uninterruptible power supply (UPS). It is installed where it is possible.

  The light source unit 13 is composed of, for example, a laser diode (LD) that outputs light (for power supply) with an output of 400 mW and a wavelength of 1480 nm, and supplies the camera device 20 with power by transmitting the light to the camera device 20. The light receiving unit 14 is, for example, a photodiode (PD), receives light (imaging signal) transmitted from the camera device 20, performs photoelectric conversion (O / E conversion), and outputs the imaging signal to the display unit 12. The display unit 12 displays an image corresponding to the imaging signal transmitted from the light receiving unit 14.

  The camera device 20 is configured to execute an imaging operation by external power from the AC power source 21 and to execute an imaging operation by receiving light transmitted from the light source unit 13. In addition, the camera device 20 performs signal processing on a moving image or a still image obtained by the imaging operation to obtain an imaging signal, photoelectrically converts the imaging signal (E / O conversion), and outputs, for example, 3 mW and a wavelength of 1310 nm (for image transmission) ) Is transmitted to the light receiving unit 14 of the center apparatus 10. The distribution capability of the camera device 20 is, for example, an effective pixel number of 640 × 480 and a frame rate of 1/3 to 30 fps (frames per second). The frame rate of 1/3 fps means that one frame is transmitted in 3 seconds.

  Specifically, as shown in FIG. 2, the camera device 20 is electrically connected to an AC power supply 21 and optically connected to the light source unit 13 of the center device 10 via the transmission path 2. 30, an imaging unit 22 that captures an image with power supplied from the power supply unit 30, and a transmission unit 23 that transmits an imaging signal obtained by the imaging unit 22 to the center apparatus 10 via the transmission path 3. 2 and 3, each thick line arrow indicates an example of a power path, and each thin line arrow indicates an example of a signal path.

  The power supply unit 30 outputs the external power supplied from the AC power source 21 to the imaging unit 22 and the transmission unit 23, and converts the light transmitted from the light source unit 13 of the center apparatus 10 into power to convert the light into the imaging unit 22 and transmission. It outputs to the means 23. The power feeding unit 30 transmits a control signal to the image capturing unit 22. The power supply unit 30 executes an imaging process to be described later on the basis of external power supplied to the power supply unit 30 and / or power by optical power supply. The detailed configuration and operation of the power supply unit 30 will be described later.

  The imaging unit 22 executes the imaging operation of the monitoring target area based on the power output from the power supply unit 30 (the external power male and / or the power by the optical power supply), and transmits the imaging signal obtained by the imaging operation. It outputs to the means 23. The transmission unit 23 converts the imaging signal output from the imaging unit 22 into light and transmits the light to the light receiving unit 14 of the center device 10.

  FIG. 3 is a block diagram showing a detailed configuration of the power feeding means 30 in FIG. The power feeding means 30 includes an input unit 31 to which external power is supplied from the AC power source 21, a light receiving unit 32 that converts light transmitted from the center device 10 through the transmission path 2, and power from the light receiving unit 32. (Hereinafter referred to as “optical power supply power”), a power storage unit 33 that stores power, a merge unit 34 that merges external power from the input unit 31 and the optical power supply power, and a voltage detection unit 36 that detects the voltage of the merge unit 34. A control unit 37 such as an MPU that controls the image pickup unit 22 based on whether external power is supplied or not, and an overall control of the camera device 20, and an FET provided between the control unit 37 and the image pickup unit 22 And a switch 38.

  External power is supplied to the input unit 31 from the AC power source 21. This external power is supplied directly or branched from an AC power source connected to a lamp or the like, and is, for example, AC 100V. The input unit 31 converts the input AC voltage into a DC voltage (AC / DC conversion) and outputs the DC voltage to the junction unit 34.

  The light receiving unit 32 is, for example, a photodiode (PD), and receives continuous light output from the light source unit 13. The power supply capability of the light receiving unit 32 is, for example, about 75 mW.

  The power storage unit 33 is made of, for example, a capacitor, and the optical power supplied to the power storage unit 33 depends on the power supply capability of the light receiving unit 32. In the present embodiment, the maximum voltage of the power storage unit 33 is, for example, 3.9V.

  The merge unit 34 is a portion where the external power supplied from the input unit 31 and the optical power supplied from the light receiving unit 32 via the power storage unit 33 merge. Both the external power supplied from the input unit 31 and the optically fed power supplied from the light receiving unit 32 join the junction unit 34. The maximum voltage of the junction 34 is, for example, 4.7V. In some cases, only one of the external power supplied from the input unit 31 or the optical power supplied from the light receiving unit 32 is supplied to the junction unit 34.

  The merge unit 34 includes a backflow prevention unit 35. The backflow prevention unit 35 includes, for example, a diode, and prevents a current from flowing back from the junction unit 34 to the AC power supply 21 side, that is, the outside of the camera device 20.

  The voltage detector 36 detects a combined voltage based on one or both of the voltage at the junction 34, that is, the external power supplied from the input unit 31 and the optical power supplied from the light receiving unit 32, and uses the detected voltage as the detected voltage. A corresponding electrical signal is transmitted to the control unit 37. In FIG. 3, the voltage detection unit 36 has a different configuration from the control unit 37, but the configuration is not limited thereto, and the voltage detection unit may be built in the control unit 37.

  The control unit 37 is, for example, a microcomputer, and includes a determination unit 37 a that determines whether external power is supplied based on the voltage detected by the voltage detection unit 36. The control unit 37 captures the entire monitoring target area with a moving image by the external power from the input unit 31 when the external power is supplied, and the optical power supply from the light receiving unit 32 when the external power is not supplied. Control is performed so that a part of the monitoring target area is imaged as a moving image in the low power consumption mode according to the power. As described above, the low power consumption mode in the present embodiment includes a mode in which a part of the monitoring target area is controlled to be captured as a moving image by the optical power supplied from the light receiving unit 32. In the present embodiment, a part of the monitoring target area is imaged as a moving image as the low power consumption mode. However, the present invention is not limited to this, and all or a part of the monitoring target area is captured as a still image in the low power consumption mode. Thus, it is possible to reduce power consumption by transmitting the still image as a frame advance image.

  The switch 38 switches ON / OFF of power supply to the imaging unit 22 in accordance with a signal transmitted from the control unit 37. In the present embodiment, the control unit 37 turns on the switch 38 when it is determined that either or both of external power and optical power supply power are supplied, and neither external power nor optical power supply is supplied. When it is determined that the switch 38 is turned off. Also, when the control unit 37 determines that the external power is not supplied and the optical power supply power is supplied, but the power does not reach sufficient power for the imaging operation in the low power consumption mode. The switch 38 is turned off.

  In this camera system 1, the power consumption of the camera device 20 is about 2.7 mW in the normal mode, and the power consumption in the low power consumption mode is approximately 0 mW. The external power supplied to the input unit 31 is about 3,000 mW, and the optical power supply supplied to the light receiving unit 32 is, for example, about 200 mW. When external power is supplied from the input unit 31, sufficient power for the imaging unit 22 to perform a normal imaging operation is supplied to the junction unit 34.

  The camera system 1 configured as described above can be applied, for example, as a system that monitors a monitoring target area including a train track such as a track. FIG. 4 shows an example when the camera system 1 of FIG. 1 is applied to a train track.

  As shown in the figure, the center apparatus 10 is installed in a building 41 such as a station building or a wiring room, for example, and is connected to the camera apparatus 20 via transmission paths 2 and 3. When an emergency power supply is installed in the building 41, the center device 10 is preferably connected to the emergency power supply.

  When monitoring the train track of the train 42, the camera device 20 is installed at a position where the monitoring target region S including the train track of the train 42 can be imaged, and is disposed in the vicinity of the track 43 on which the train 42 travels, for example. . In this case, for example, the camera device 20 captures an image of the entire monitoring target area S in a normal state, and corresponds to a part of the monitoring target area S when supply of electric power (external power) from a later-described lamp power source is stopped during a disaster. It is possible to control so that only the section corresponding to the train track including the track 43 is picked up.

  An electric lamp 45 is usually installed on the track 43 that is one of the train tracks, and an electric wire 46 that supplies electric power to the electric lamp 45 is laid in a wiring path 44 near the track 43. Therefore, the electric wire 46 may be connected to the input unit 31 (see FIG. 3) of the camera device 20 to supply power to the camera device 20 from the electric wire 46. The voltage of the electric power supplied to the camera device 20 can be various values depending on the electric power supplied to the lamp 45, and is, for example, AC100V, and is converted into a predetermined DC voltage by a converter (not shown). . Thus, the camera system 1 can be easily constructed by supplying the lamp power as external power to the camera device 20.

  In FIG. 4, transmission lines 2 and 3 for connecting the center apparatus 10 and the camera apparatus 20 are installed. For example, when an existing transmission path such as an optical fiber cable for communication is installed, The center apparatus 10 and the camera apparatus 20 may be connected using the existing optical fiber cable or the like without newly providing an optical fiber cable or the like. For example, the transmission paths 2 and 3 are optical fiber cables including one or a plurality of optical fibers, and other than light transmitted between the camera device 20 and the center device 10 via the optical fiber cables. Light is transmitted. Also, other than the light transmitted between the center apparatus 10 and the camera apparatus 20 through the existing optical fiber cable using the existing optical fiber cable including the transmission paths 2 and 3 and other optical fibers. May be transmitted through the other optical fiber different from the transmission paths 2 and 3. At this time, the other light is, for example, light transmitted between communication facilities related to railway operation. In this case, since the installation work of the transmission lines 2 and 3 is not required, the camera system 1 can be easily constructed.

[Operation of Camera System and Camera Device]
FIG. 5 is a flowchart showing an imaging process executed by the control unit 37 of FIG. In this imaging process, a case where the power of the lamp 45 in FIG. 4 is supplied to the camera device 20 as external power will be described as an example.

  In FIG. 5, first, the control unit 37 detects the voltage of the merging unit 34 with the voltage detection unit 36 (step S <b> 11), and determines whether external power is supplied. Specifically, the predetermined voltage V1 is set to, for example, 3.9 V, the predetermined voltage V2 is set to, for example, 2.3 V, and the detected voltage V of the junction 34 is set to the predetermined voltage V1 (first predetermined voltage) and the predetermined voltage V2 (V2 <V1, second predetermined voltage). When the voltage V of the merge unit 34 detected in step S11 is higher than the predetermined voltage V1 (V1 <V) (step S12), it is determined that the camera device 20 is supplied with external power from the lamp power source (step S12). S13). Then, the switch 38 is turned on to supply external power to the imaging unit 22, and control is performed so that the entire monitoring target region S is captured as a moving image by the external power from the input unit 31 (step S14) (normal mode). Next, the entire moving image of the monitored region S that has been imaged is continuously output to the center device 10 by the transmission unit 23, for example, at 30 fps (step S15).

  For example, when the monitoring target area S is a section including the train track L, in the normal mode, the entire moving image S1 corresponding to the monitoring target area S is displayed on the display unit 12 of the center apparatus 10 as shown in FIG. Is displayed continuously. Thereby, the user can continuously monitor the entire monitoring target region S including the train track L using the entire moving image S1 displayed on the display unit 12 of the center device 10.

  Further, when the voltage V of the junction 34 detected in step S11 is equal to or lower than the predetermined voltage V1 and exceeds the predetermined voltage V2 that is smaller than the predetermined voltage V1 (V2 <V ≦ V1) (step S12). Then, it is determined that the camera device 20 is supplied with only the optical power supply (step S16). Then, the switch 38 is turned on to supply the optical power supply to the imaging unit 22, and the optical power supply power is used to control the section S ′ that is a part of the monitoring target area S to be captured as a moving image (step S17). (Low power consumption mode). That is, in this imaging process, when the camera device 20 is supplied with power only by optical power feeding, only a predetermined section set in advance or only a subject to be monitored is selectively imaged in the monitoring target area S. It is possible.

  The section S ′, which is a part of the monitoring target area S, is an important area that needs to be monitored particularly when a disaster or the like occurs in the monitoring target area S imaged by external power in the normal mode. For example, it is a section corresponding to the train track L. The section corresponding to this train track L may be a section that includes the train track L and is narrower than the entire monitoring target region S, or may be a section of only the train track L.

  Thereafter, the moving image of the section S ′ that is a part of the imaged monitoring target region S is continuously output to the center device 10 at, for example, 30 fps (step S18).

  In this low power consumption mode, as shown in FIG. 6B, the moving image S2 corresponding to the section S ′ that is a part of the monitoring target area S is continuously displayed on the display unit 12 of the center apparatus 10. . When the monitoring target region S is a region including the train track L, the section S ′ is a region including the train track L and narrower than the monitoring target region S, for example. The user can continuously monitor the section S ′ corresponding to the train track L using the moving image S <b> 2 displayed on the display unit 12 of the center device 10.

  When the voltage V of the junction 34 detected in step S11 is less than or equal to the predetermined voltage V2 (V ≦ V2) (step S12), the imaging means 22 has not reached a voltage that can reliably operate in the low power consumption mode. Is determined, the switch 38 is turned OFF, and the process proceeds to step S19. If a predetermined time has elapsed since the previous imaging process, the process returns to step S11 and the same process as described above is performed (step S19). If the predetermined time has not elapsed since the previous imaging process, Then, the imaging process ends. If the predetermined time in the process of step S19 is set short, the time interval between the imaging process executed last time and the imaging process executed this time is shortened. Therefore, it is determined at an early stage that the supply of external power has stopped. It is possible to switch to the power consumption mode. Further, when the supply of external power is resumed, it is possible to quickly switch from the low power consumption mode to the normal mode.

  As described above, according to the present embodiment, when external power is supplied, the control unit 37 captures the entire monitoring target area S with a moving image using the external power from the input unit 31 and supplies the external power. If not, control is performed so that the section S ′, which is a part of the monitoring target area S, is captured as a moving image in the low power consumption mode by the power from the light receiving unit 32. Accordingly, the entire moving image S1 of the monitoring target area S can be acquired by the external power in the normal mode, and the moving image S2 of the train track L is acquired in the low power consumption mode even when the supply of the external power is stopped. be able to. Therefore, even if a power failure occurs in the monitoring target area S, the center device 10 can continuously acquire the minimum required moving image S2 of the train track L in the monitoring target area S. Therefore, it is possible to continuously and easily monitor the monitoring target area S with a highly reliable power supply.

  In addition, since the camera device 20 is not provided with power storage means such as a battery, it is possible to prevent imaging failure due to battery exhaustion, and to greatly reduce maintenance loads such as periodic inspection and replacement. Furthermore, since it is not necessary to provide a battery or other power storage means in the camera device 20, the camera device 20 can be installed in a place where there are no people at all times or where it is difficult for people to approach. Information on the region S can be easily acquired.

  Moreover, since the center apparatus 10 can be installed in a place where people are always present, maintenance is easy. Furthermore, since it can be installed in a place where an emergency power supply can be secured, it is possible to continue supplying power to the center apparatus 10 even in the event of a disaster, and information on the monitoring target area S is continuously acquired from the camera apparatus 20. Thus, the monitoring target area can be continuously monitored.

  Further, by adopting a configuration in which external power is supplied to the input unit 31 of the camera device 20 from the electric wire 46 that supplies power to the lamps 45 provided on the train track L, external power can be easily supplied from existing electric wires and facilities. Can be obtained. In addition, even when a power failure occurs, the train track L that is a part of the monitoring target region S is imaged by the optical power supplied from the light receiving unit 32, and thus the imaging signal of the train track L is continuously acquired. It is possible to monitor and secure safe and stable train operation.

  Furthermore, since the lamps 45 and the like provided on the train track L are normally laid along the train track L, a plurality of camera devices 20, 20,... Can be arranged along the train track L. it can. Thereby, the degree of freedom of the place that can be selected as the monitoring target region S is increased, and the safe and stable operation of the train 42 can be ensured over a wide range.

  The camera device, the camera system, and the control method of the camera device according to the above embodiment have been described above, but the present invention is not limited to the described embodiment, and various modifications and changes can be made based on the technical idea of the present invention. It can be changed.

  In the present embodiment, the control unit 37 is provided in the power supply unit 30, but is not limited thereto, and may be provided in the camera device 20.

  The center device 10 includes the light receiving unit 14 that receives the light (optical signal) transmitted from the camera device 20, but is not limited thereto, and receives the imaging signal (electric signal) transmitted from the camera device 20. You may provide the receiving part.

  The external power is supplied from the lamp power supply, but is not limited thereto, and may be supplied from the lamp power supply, the railway signal power supply, the railroad crossing facility power supply, or the station premises power supply. In addition, the external power may be supplied from at least one of a lamp power source, a railway signal power source, a railroad crossing facility power source, and a station premises power source provided on the train track.

  In addition, the camera device 20 images the monitoring target area S including the train track of the train 42. However, the camera apparatus 20 is installed in the station premises and images other monitoring target areas including predetermined sections in the station premises. Also good. According to this configuration, even when the external power is not supplied to the camera device 20 for some reason, it is possible to continuously monitor the monitoring target area in the station premises.

  In the present embodiment, when the detection voltage V of the junction unit 34 is equal to or lower than the predetermined voltage V1 and exceeds the predetermined voltage V2 (V2 <V ≦ V1), the control unit 37 is a part of the monitoring target region S. The section S ′ is imaged with a moving image (step S17), but is not limited thereto. For example, when the detection voltage V of the merging unit 34 is equal to or lower than the predetermined voltage V1 and exceeds the predetermined voltage V2, the control unit 37 captures the entire monitoring target region S with a moving image having a resolution lower than that in the normal mode. May be.

  In addition, in the normal mode (V1 <V), when the monitoring target area S is monitored at night, the control unit captures the entire monitoring target area S with a moving image having higher photosensitivity than during daytime imaging. Also good. Thereby, the favorable dark part imaging of the monitoring object area | region S can be performed, and the monitoring precision of the monitoring object area | region S can be improved. In particular, by installing the camera device 20 in the boundary area between the station premises and the external section, at a railroad crossing, etc., it is possible to perform high-precision monitoring of the boundary area at night, and to improve safety and crime prevention. It becomes possible.

DESCRIPTION OF SYMBOLS 1 Camera system 2 Transmission path 3 Transmission path 10 Center apparatus 11 DC power supply 12 Display part 13 Light source unit 14 Light receiving part 20 Camera apparatus 21 AC power supply 22 Imaging means 23 Transmission means 30 Power supply means 31 Input part 32 Light receiving part 33 Power storage part 34 Merge Section 35 Backflow prevention section 36 Voltage detection section 37 Control section 38 Switch 41 Building 42 Train 43 Line 44 Wiring path 45 Electric light 46 Electric wire L Train track S Monitoring target area S 'Section S1 Overall video S2 Video

Claims (5)

A power supply unit having an input unit to which external power is supplied, and a light receiving unit that converts light transmitted from the center device through the transmission path into power;
Imaging means for imaging with the power supplied from the power supply means;
Transmitting means for transmitting an imaging signal obtained by the imaging means to the center device via the transmission path;
A control unit that controls the imaging unit based on whether or not the external power is supplied,
The controller is
When the external power is supplied, the whole monitoring target area is imaged with the external power from the input unit, and when the external power is not supplied, the low power consumption mode is set by the power from the light receiving unit. The camera device is controlled to take an image of the monitoring target area.   The camera device according to claim 1, wherein the low power consumption mode is a mode in which a part of the monitoring target area is controlled to be captured as a moving image. The power supply means further includes a merging unit that merges the power from the input unit and the power from the light receiving unit,
The camera apparatus according to claim 1, wherein presence / absence of supply of the external power is determined based on a voltage of the merging unit.   When the voltage of the junction unit is higher than a first predetermined voltage, the control unit images the monitoring target area with external power from the input unit, and the voltage of the junction unit is equal to or lower than the first predetermined voltage. 4. The control according to claim 3, wherein when the second predetermined voltage, which is smaller than the first predetermined voltage, is exceeded, control is performed so that the monitoring target region is imaged by power from the light receiving unit. Camera device. A camera system comprising a center device and a camera device connected to the center device via a transmission line,
The camera device is
A power supply unit having an input unit to which external power is supplied, and a light receiving unit that converts light transmitted from the center device through the transmission path into power;
Imaging means for imaging with the power supplied from the power supply means;
Transmitting means for transmitting an imaging signal obtained by the imaging means to the center device via the transmission path;
When the external power is input, the entire monitoring target area is imaged with the external power from the input unit, and when the external power is not input, the power from the light receiving unit is used in the low power consumption mode. A control unit that controls to image the monitoring target area,
The center device is
A light source unit for sending light to the camera device via the transmission path;
A receiving unit that receives the imaging signal transmitted from the camera device;
A camera system characterized by that.

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