Cameras, Trains, and Surveillance Systems

Abstract

To provide a vehicle-side camera capable of simplifying equipment such as wiring in installing a plurality of vehicle-side cameras on a vehicle.SOLUTION: A camera (C11) is a binocular type camera for imaging objects of imaging getting on / off a train (1) at a plurality of doors (101 to 106, 201 to 206) that the train comprises, and the camera comprises a first camera (11N) which has a first optical axis (AX1) and a first focal length, and a second camera (11D) which has a second optical axis (AX2) not parallel with the first optical axis and a second focal length longer than the first focal length.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One aspect of the present invention relates to a camera or the like. [Background technology]

[0002] Patent Document 1 discloses a monitoring system that displays door camera images captured by door cameras installed near the doors of a vehicle on a monitor in the driver's cab. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-92136 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology described in Patent Document 1, door cameras are installed on the left and right exterior walls of each car in a train, and the video data captured by each of the multiple door cameras is transmitted to a monitor. Therefore, a door camera must be installed on the exterior wall of each car in accordance with the number of door cameras installed on the train. Furthermore, forming a network including a transmission device and various electrical wiring that connects each of the multiple door cameras to the monitors complicates the wiring structure within the car.

[0005] A camera installed on the exterior wall of a vehicle is called a vehicle side camera (vehicle side camera). The present invention aims to realize a vehicle side camera that can simplify the installation of wiring and other equipment when installing multiple vehicle side cameras in a vehicle. [Means for solving the problem]

[0006] In order to solve the above problems, a camera according to one embodiment of the present invention is a binocular camera that captures images of subjects getting on and off through multiple doors on a train, and includes a first camera having a first optical axis and a first focal length, and a second camera having a second optical axis that is not parallel to the first optical axis and a second focal length that is longer than the first focal length.

[0007] In addition, a train according to one embodiment of the present invention is a train provided with multiple doors for boarding and alighting, and is equipped with a first camera and a second camera provided on the side of a first end of the train, facing toward a second end of the train, and capturing images of subjects boarding and alighting through at least some of the multiple doors, wherein the first camera has a first optical axis and a first focal length, and the second camera has a second optical axis and a second focal length that is longer than the first focal length, and the angle formed by the second optical axis and the horizontal direction is smaller than the angle formed by the first optical axis and the horizontal direction.

[0008] In addition, one aspect of the present invention provides a monitoring system for a train having multiple doors for boarding and alighting, the train having multiple cars, and including a first camera and a second camera mounted on the side of a first end of the car, facing toward a second end of the car, and capturing images of subjects boarding and alighting through at least some of the multiple doors, and a display device that displays images represented by the imaging data of the first camera and the second camera, respectively, wherein the first camera has a first optical axis and a first focal length, the second camera has a second optical axis and a second focal length that is longer than the first focal length, and the angle formed by the second optical axis and the horizontal direction is smaller than the angle formed by the first optical axis and the horizontal direction. [Effects of the Invention]

[0009] According to one aspect of the present invention, it is possible to simplify the installation such as wiring when installing a plurality of vehicle-side cameras in a vehicle. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a schematic diagram illustrating an external configuration of a train according to a first embodiment of the present invention. [Figure 2] 1 is a perspective view showing the external configuration of a camera according to a first embodiment of the present invention. [Figure 3] 1 is a front view showing the external configuration of a camera according to a first embodiment of the present invention. [Figure 4] FIG. 1 is a bottom view showing the external configuration of a camera according to a first embodiment of the present invention. [Figure 5] 1 is a perspective view showing an example of the internal configuration of a camera according to a first embodiment of the present invention. [Figure 6] 1 is a plan view showing an example of the internal configuration of a camera according to a first embodiment of the present invention. [Figure 7] 2 is a schematic diagram for explaining the imaging fields of a first camera and a second camera included in the camera according to the first embodiment of the present invention. FIG. [Figure 8] FIG. 10 is a side view schematically showing the external configuration of a train according to a second embodiment of the present invention. [Figure 9] FIG. 10 is a functional block diagram showing the configuration of a monitoring system according to a third embodiment of the present invention. [Figure 10] FIG. 2 is a diagram illustrating an example of a display screen of a monitor. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. However, the following description is intended to facilitate a better understanding of the gist of the invention and, unless otherwise specified, does not limit the present invention. For the sake of convenience, the drawings referred to in the following description show only the main components necessary for explaining the embodiment in a simplified form, and descriptions of well-known technical matters are omitted as appropriate for brevity. Therefore, the camera and the like in this embodiment may optionally include well-known components not shown in the drawings referred to. Furthermore, the shapes and dimensions of the components in the drawings do not necessarily reflect the actual shapes and dimensions, and have been changed as appropriate for clarity and simplification of the drawings.

[0012] In this embodiment, for example, a vehicle-side camera installed on the side (external wall surface of the vehicle body) of multiple railway cars that make up a train operated on a regular railway will be described. In the following description, railway cars will be abbreviated simply as cars, and vehicle-side cameras will be abbreviated simply as cameras. The camera and monitoring system of this embodiment can also be applied to vehicles other than railway cars as appropriate. For example, it can be applied to vehicles such as streetcars and railless trains (trolleybuses). It can also be applied to vehicles such as articulated buses.

[0013] In the following description, first, an overview of a train on which a camera according to this embodiment is installed and its advantages will be described, and then specific examples of the camera will be described.

[0014] <Train Overview> Fig. 1 is a schematic diagram showing the external configuration of a train 1 according to this embodiment. The diagram indicated by reference numeral 1001 in Fig. 1 is a plan view showing the configuration of the train 1, and the diagram indicated by reference numeral 1002 in Fig. 1 is a side view showing the configuration of the train 1.

[0015] As shown in FIG. 1 , the train 1 in this embodiment is a two-car formation consisting of a first car V1 and a second car V2, and the first car V1 and the second car V2 are coupled to each other via a coupling section 30. The specific structure of the coupling section 30 is not particularly limited, and a known structure can be applied. Furthermore, the train 1 is not limited to a two-car formation, but may be a three-car or four-car formation. The train 1 may be coupled with five or more cars. For example, if the train 1 is a formation of three or more cars, the first car V1 may be the first or last car in the formation, or may be an intermediate car located between the first and last cars. The first car V1 may be a powered trailer car or an unpowered trailer car. The second car V2 may be a car located ahead of or behind the first car V1 and adjacent to the first car V1. With reference to the following explanation, it is easy to understand that the cameras described below can be installed at appropriate intervals depending on the number of vehicles included in train 1, and that the same effects as those of the embodiments described below can be achieved even in a configuration in which multiple cameras are installed (in other words, a train having multiple first vehicles V1).

[0016] In the example shown in FIG. 1, the first car V1 is the leading car located on the side of the train 1 in the direction of travel D1. The train 1 is stopped within a station, with a platform PF located on the left side of the train 1 as it faces the direction of travel D1. Hereinafter, for the first car V1 and the second car V2 of the train 1, the side facing the direction of travel D1 may be referred to as the front side, and the opposite side as the rear side. One end of each car extending longitudinally along the direction of travel D1 is referred to as the first end E1, and the opposite end is referred to as the second end E2. In FIG. 1, for clarity of illustration, reference numerals are used to denote the first end E1 located on the front side of the first car V1 and the second end E2 located on the rear side of the second car V2.

[0017] The first vehicle V1 has three doors 101, 102, 103 arranged in sequence from front to rear on one side, and three doors 104, 105, 106 arranged in sequence from front to rear on the other side. The first vehicle V1 may have a monitor (display device) 120 installed, for example, at the front side of the interior of the vehicle, and the monitor 120 may be installed in the driver's seat (not shown).

[0018] In the train 1 of this embodiment, the first vehicle V1 and the second vehicle V2 may have the same or substantially the same structure. In other words, the second vehicle V2 may be a vehicle obtained by flipping the first vehicle V1 front to back. The second vehicle V2 has doors 201, 202, and 203, which may correspond to doors 101, 102, and 103 of the first vehicle V1, respectively. The second vehicle V2 also has doors 204, 205, and 206, which may correspond to doors 104, 105, and 106 of the first vehicle V1, respectively. The second vehicle V2 may have a monitor 220 on its rear side, which may correspond to monitor 120 of the first vehicle V1. In the following description, the description of the first vehicle V1 also applies to the second vehicle V2 unless otherwise specified. Therefore, a detailed description of the second vehicle V2 will be omitted.

[0019] In recent years, there has been a demand for the use of door cameras to check passengers getting on and off (in other words, to check safety) on trains 1 that run on local routes, etc. This is because on local routes, the trains 1 are often one-man trains, meaning that the trains 1 often have only one crew member.

[0020] The direction of travel of train 1 may reverse, and the position of platform PF changes depending on the shape of the station. Furthermore, displaying images captured with a field of view oriented to look behind the train's direction of travel on a monitor is generally less likely to cause discomfort to the driver. Therefore, it is envisioned that door cameras will be installed, for example, on the front left and right sides and the rear left and right sides of first vehicle V1, i.e., at each of the four corners of first vehicle V1 in a plan view.

[0021] However, for example, if door cameras are installed at the four corners of each of the first vehicle V1 and the second vehicle V2, a total of eight door cameras must be attached to the exterior walls of the vehicles and electrical wiring must be installed to each door camera. Furthermore, a network cable must be run from the door camera installed in the second vehicle V2 to the monitor 120 of the first vehicle V1, and a cable connection between the vehicles must also be made at the connecting unit 30 using, for example, jumper wires.

[0022] The inventors conducted extensive research and came up with the present invention by focusing on the above-mentioned novel problem. In the train 1 of this embodiment, a camera C11 is provided on one side of the first end E1, and a camera C12 is provided on the other side. The cameras C11 and C12 are car-mounted cameras that capture images of the doors and their surroundings from outside the car. In the example shown in FIG. 1, the camera C11 is provided on the side of the left side (platform PF side) in the direction of travel D1, facing the second end E2 of the train 1. The camera C11 may be located, for example, above a crew door (not shown).

[0023] In the following description, the description of camera C11 also applies to camera C12 unless otherwise specified. Therefore, a repeated description of camera C12 will be omitted. In addition, the second vehicle V2 is provided with cameras C21 and C22, which may correspond to cameras C11 and C12 of the first vehicle V1, respectively. Therefore, a repeated description of cameras C21 and C22 will be omitted.

[0024] The camera C11 includes a first camera 11N and a second camera 11D used to capture images relatively farther away than the first camera 11N. The camera C11 captures images of subjects getting on and off through multiple doors (doors 101-103, doors 204-206) equipped on the train 1. The camera C11 is a so-called binocular camera in which the first camera 11N and the second camera 11D are housed in a single housing 5. The subjects may be people or various types of movable objects. While FIG. 1 illustrates passengers P1 and P2 as examples of subjects to be captured, examples of the objects include animals (e.g., assistance dogs) or autonomous or remotely controlled mobile machines (e.g., transport robots).

[0025] First camera 11N has a first optical axis and a first focal length, and second camera 11D has a second optical axis that is not parallel to the first optical axis and a second focal length that is longer than the first focal length. Camera C11 differs from a stereo camera, which is a type of binocular camera, in that the optical axes of first camera 11N and second camera 11D intersect with each other.

[0026] The orientations of the first and second optical axes correspond to the orientations of the lenses in first camera 11N and second camera 11D, respectively. The focal lengths of first camera 11N and second camera 11D correspond to the lens configurations of the respective cameras. Generally, the longer the focal length, the narrower the angle of view.

[0027] The first camera 11N and the second camera 11D can capture images at a predetermined frame rate within an imaging field determined by the installation angle and lens configuration within the housing 5. The imaging field of the first camera 11N includes the multiple doors (doors 101, 102, 103) of the first vehicle V1 and their surroundings, which are located on the side of the train 1 where the camera C11 is installed. The imaging field of the second camera 11D includes the multiple doors (doors 206, 205, 204) of the second vehicle V2 and their surroundings, which are located on the side of the train 1 where the camera C11 is installed.

[0028] In FIG. 1, the viewing area A1 included in the field of view of the first camera 11N is indicated by a long-chain line. This viewing area A1 is a schematic area, and, for example, the very end of the viewing area A1 may correspond to the far-end limit of the depth of field of the first camera 11N. The viewing area A1 includes a first monitoring area, which is an area where it is necessary to check whether or not a passenger P1 is near the first vehicle V1 for safety confirmation, etc. Such a first monitoring area is virtually indicated by diagonal hatching slanting upward to the right in the diagram indicated by reference numeral 1002 in FIG. 1.

[0029] 1, the viewing area A2 included in the field of view of the second camera 11D is indicated by a dashed line. This viewing area A2 is a schematic area, and, for example, the very end of the viewing area A2 may correspond to the far end of the depth of field of the second camera 11D. The viewing area A2 includes a second monitoring area, which is an area where it is necessary to check whether or not a passenger P2 is near the second vehicle V2 for safety reasons. This second monitoring area is virtually indicated by diagonal hatching slanting upward to the left in the diagram indicated by reference numeral 1002 in FIG. 1.

[0030] A transmission device 110 may be provided in the first vehicle V1, and the cameras C11 and C12 may be connected to the monitor 120 via the transmission device 110 by a network cable or the like.

[0031] According to the above configuration, first camera 11N, which has a relatively short focal length, can capture an image of viewing area A1, which is close to the installation position of camera C11, and second camera 11D, which has a relatively long focal length, can capture an image of viewing area A2, which is far from the installation position of camera C11. Although the angle of view of second camera 11D is narrower than the angle of view of first camera 11N, because the first optical axis and the second optical axis are not parallel, it is possible to fit a desired imaging range within the angle of view of second camera 11D.

[0032] By installing a single camera C11 including a first camera 11N and a second camera 11D in the first car V1, it is possible to simplify wiring and other equipment compared to installing car-side cameras (door cameras) at separate locations on each car of the train 1. This reduces the amount of electrical wiring and electronic equipment used. Furthermore, by reducing the construction work required to install the car-side cameras, it is possible to achieve cost savings. Furthermore, in the train 1, it is not necessary to transmit video data from the door camera of the second car V2 to the monitor 120. As a result, the first car V1 and the second car V2 may form separate networks. Therefore, the wiring structure inside the first car V1 can be effectively simplified.

[0033] Note that the train 1 does not necessarily have to be equipped with cameras C21 and C22. The traveling direction D1 of the train 1 may be fixed to a predetermined orientation. The train 1 may also travel in the opposite direction to the traveling direction D1, i.e., the second car V2 may be the leading car. In this case, a network may be formed so that the images from cameras C11 and C12 can be displayed on the monitor 220. In other words, images captured with an imaging field of view oriented to check the front side relative to the traveling direction may be displayed on the monitor. This can further reduce the number of installed cameras.

[0034] <Camera> An example of a specific configuration of the camera C11 in this embodiment will be described below with reference to Figs. 2 to 6. Fig. 2 is a perspective view showing the exterior configuration of the camera C11 in this embodiment. Fig. 3 is a front view showing the exterior configuration of the camera C11. Fig. 4 is a bottom view showing the exterior configuration of the camera C11. Fig. 4 shows the state before the camera C11 is attached to the first vehicle V1. Fig. 5 is a perspective view showing an example of the internal configuration of the camera C11. Fig. 6 is a plan view showing an example of the internal configuration of the camera C11. Figs. 5 and 6 show a state in which a part of the housing (a cover) has been removed.

[0035] As shown in FIGS. 2 to 6, the camera C11 can be installed, for example, on an outer wall W1 that constitutes the side surface of the first vehicle V1. The camera C11 includes a housing 5, and the housing 5 can accommodate the first camera 11N and the second camera 11D therein in a watertight manner. The housing 5 includes, for example, a board 60 to which the first camera 11N and the second camera 11D are fixed, and a lid 70 that covers one surface 60A of the board 60 and has a shape that forms an internal space of the housing 5. In the camera C11 of this embodiment, the first camera 11N and the second camera 11D may be camera modules fixed to the board 60.

[0036] The lid portion 70 may have a lid main body portion 71 and a window portion 75. The lid main body portion 71 has a flange portion 72, and the camera C11 may be fixed to the outer wall W1 by screws or the like using the flange portion 72. The lid main body portion 71 may have a shape such that the flange portion 72 is located near the outer edge of the substrate 60 (excluding the front portion where the window portion 75 is attached) when the lid portion 70 and the substrate 60 are combined.

[0037] The window portion 75 has an optical window 76 and a frame portion 77 that surrounds and holds the outer edge of the optical window 76. The window portion 75 is located on the front side of the camera C11 so that both the first optical axis AX1 of the first camera 11N and the second optical axis AX2 of the second camera 11D pass through the single optical window 76. The optical window 76 is solid rather than hollow and is formed from a light-transmitting material. Examples of light-transmitting materials include glass and resin. The frame portion 77 is used to fix the window portion 75 to the lid main body 71 with screws or the like to form the lid portion 70. The lid portion 70 may have a packing (not shown) interposed between the lid main body 71 and the window portion 75.

[0038] The surface 60A of the substrate 60 may be provided with mounting portions for mounting the first camera 11N and the second camera 11D. In the example shown in FIGS. 5 and 6, the surface 60A of the substrate 60 is provided with a plurality of bosses (protrusions) having a protruding shape as mounting portions. The substrate 60 has (i) four bosses 61 used to fix the first camera 11N and (ii) four bosses 62 used to fix the second camera 11D, formed on the surface 60A. The bosses 61 and 62 have screw holes.

[0039] First camera 11N includes a lens unit 81 and a base unit 89. Lens unit 81 may be attached to base unit 89. A first element unit, for example, may be provided inside base unit 89. The first element unit includes, for example, a sensor board, a memory board, and an encoder board. The sensor board and the memory board may be electrically connected to each other by a connector, and the memory board and the encoder board may be electrically connected to each other by another connector.

[0040] Known components can be used for the lens unit 81 and the first element unit, and the specific structure is not particularly limited. Briefly described, the lens unit 81 has a first optical axis AX1 and a first focal length, and is, for example, a single-focus lens including a lens group made up of multiple lenses. The first focal length can be adjusted by the lens configuration of the lens unit 81.

[0041] The sensor board may be a circuit board including an image sensor, for example, a CMOS (Complementary Metal Oxide Semiconductor) sensor. The memory board may include, for example, an FPGA (Field Programmable Gate Array), and a circuit including a memory (storage element) may be configured by the FPGA. The memory board stores image data output as a digital signal from the sensor board. A first cable (not shown) is connected to the encoder board, and the first cable is connected to a transmission device 110 (see FIG. 1). The encoder board encodes the image data acquired from the memory board into a predetermined data format and outputs it to the transmission device 110 (see FIG. 1) using the first cable. The first cable may include a power supply cable and a communication cable, and the specific configuration is not particularly limited.

[0042] The base portion 89 has four mounting portions 89X provided to correspond to the four bosses 61 of the substrate 60. The mounting portions 89X have holes 89H through which screws are inserted. The first camera 11N can be fixed to the substrate 60 by aligning the holes of the mounting portions 89X with the screw holes of the bosses 61 and fastening them with screws.

[0043] In the example shown in FIGS. 5 and 6, the hole 89H of the mounting portion 89X1, which is one of the four mounting portions 89X, is circular, while the holes 89H of the other three mounting portions 89X2 have shapes with long axes. More specifically, the hole 89H of the mounting portion 89X2 has a hole shape with play (position adjustment area) so that the mounting portion 89X2 and the boss 61 can be screwed together even if the base portion 89 is rotated slightly around the mounting portion 89X1. This allows the mounting angle of the base portion 89 to the substrate 60 (i.e., the mounting angle of the first camera 11N) to be adjusted to a certain extent. The mounting portion 89X1 may be, for example, the mounting portion 89X located on the side closer to the optical window 76 and the side closer to the second camera 11D among the four mounting portions 89X.

[0044] The second camera 11D includes a lens unit 91 and a base unit 99. The lens unit 91 may be attached to the base unit 99. A second element unit, for example, may be provided inside the base unit 99. The second element unit includes, for example, a sensor board, a memory board, and an encoder board. The lens unit 91 and the second element unit in the second camera 11D can be generally understood by referring to the description of the lens unit 81 and the first element unit of the first camera 11N above. The lens unit 91 has a second optical axis AX2 and a second focal length and may be, for example, a single-focus lens. The lens unit 91 has a lens configuration with the second focal length being longer than the first focal length of the lens unit 81. A second cable (not shown) is connected to the encoder board in the second element unit, and the second cable is connected to the transmission device 110 (see FIG. 1). The second cable may include a power supply cable and a communication cable, and the specific configuration is not particularly limited.

[0045] The base part 99 has four mounting parts 99X provided to correspond to the four bosses 62 of the substrate 60. The mounting parts 99X have holes through which screws are inserted, and the second camera 11D can be fixed to the substrate 60 by aligning the positions of the holes of the mounting parts 99X with the screw holes of the bosses 62 and fastening them with screws.

[0046] The second optical axis AX2 may be perpendicular or approximately perpendicular to the surface of the optical window 76. The first camera 11N may be installed at an angle with respect to the surface of the optical window 76, and the first optical axis AX1 is inclined with respect to the surface of the optical window 76. The angle at which the first optical axis AX1 of the first camera 11N and the second optical axis AX2 of the second camera 11D intersect with each other is referred to as θ0. The angle θ0 is an acute angle. The angle θ0 may be, for example, 10° or more and 45° or less, or 10° or more and 20° or less.

[0047] As described above, in the camera C11 of this embodiment, the fixed position of the first camera 11N on the substrate 60 is adjustable. This allows adjustment of the angle θ0 of the first optical axis AX1 with respect to the second optical axis AX2. Therefore, the range that can be imaged by the first camera 11N can be easily adjusted. In addition, the range that can be imaged by the second camera 11D may be adjusted by the installation angle of the camera C11 with respect to the outer wall W1.

[0048] First camera 11N and second camera 11D may be attached perpendicular to substrate 60, or may be attached at a slight inclination with respect to substrate 60. First camera 11N and second camera 11D may be attached to substrate 60 so that lens unit 81 and lens unit 91, respectively, are inclined in a direction away from substrate 60.

[0049] The angle of inclination of the first optical axis AX1 of the first camera 11N relative to the board 60 is referred to as the first inclination angle, and the angle of inclination of the second optical axis AX2 of the second camera 11D relative to the board 60 is referred to as the second inclination angle. The first and second inclination angles refer to elevation angles when the board 60 is considered to be a horizontal plane. Note that when the camera C11 is attached to the first vehicle V1, the inclination relative to the board 60 corresponds to the inclination relative to the outer wall W1. The first inclination angle may be larger than the second inclination angle, thereby enabling the camera C11 to capture a wider range of images around the doors (doors 101 to 103) of the first vehicle V1. For example, the first inclination angle may be 5°, and the second inclination angle may be 2°.

[0050] In a state in which the camera C11 is attached to the first vehicle V1, the first camera 11N may be positioned higher in the vertical direction (height direction) of the first vehicle V1 than the second camera 11D. This makes it easier to accommodate the first camera 11N and the second camera 11D in the housing 5 in a relatively small space.

[0051] The camera C11 may include a hole 68 that penetrates from the front surface 60A to the opposite back surface 60B of the substrate 60. The number of the hole 68 may be one or more. The first cable and the second cable may be inserted through the hole 68 and drawn out to the outside of the housing 5. The hole 68 may be provided with, for example, a bushing.

[0052] A packing P may be provided on the peripheral edge of the surface 60A of the substrate 60, and by attaching the cover 70 and the substrate 60 via the packing P, the watertightness of the housing 5 can be improved. An intermediate member 40 (see FIG. 3) may be interposed between the camera C11 and the outer wall W1. The intermediate member 40 may be, for example, a metal plate having passages for the first cable and the second cable.

[0053] (Example of camera's field of view) FIG. 7 is a schematic diagram illustrating the imaging fields of view of the first camera 11N and the second camera 11D included in the camera C11 of this embodiment. As shown in FIG. 7, the angle of view of the first camera 11N is referred to as θ1. The focal length of the first camera 11N and the angle of view θ1 are related to each other. The focal length of the first camera 11N may be set so that the depth of field includes an area further back (rearward) than the rear long side S12 of the rectangular opening of the rearmost door 103 of the first vehicle V1. The mounting angle and the angle of view θ1 of the first camera 11N with respect to the first vehicle V1 may be set so that the imaging field of view of the first camera 11N includes an area above the height position H1 of the doors (doors 101 to 103) of the first vehicle V1 and includes an area further forward (forward) than the front long side S11 of the rectangular opening of the frontmost door 101 of the first vehicle V1. In the example shown in FIG. 7, the angle of view θ1 is 58°.

[0054] As shown in FIG. 7, the angle of view of the second camera 11D is referred to as θ2. The focal length of the second camera 11D and the angle of view θ2 are related. The focal length of the second camera 11D may be set so that the depth of field includes the area behind the rear long side S22 of the rectangular opening of the rearmost door 204 of the second vehicle V2, and the area in front of the front long side S21 of the rectangular opening of the frontmost door 206 of the second vehicle V2. The mounting angle of the second camera 11D to the first vehicle V1 and the angle of view θ2 may be set so that the imaging field of the second camera 11D includes an area above the height position H2 of the doors (doors 204 to 206) of the second vehicle V2 and includes the area in front of the long side S21. In the example shown in FIG. 7, the angle of view θ2 is 10.5°.

[0055] By installing first camera 11N and second camera 11D on first vehicle V1 as described above, the effects of camera C11 can be achieved. Therefore, in another embodiment, first camera 11N and second camera 11D do not need to be housed in a single housing 5, which will be described in detail later as embodiment 2.

[0056] (Other configurations) (a) The number of doors provided in each car (for example, the first car V1 and the second car V2) of the train 1 is not particularly limited.

[0057] (b) The first cable and the second cable may be combined into one cable inside the housing 5, or may be physically bundled into one cable and inserted into the hole 68.

[0058] (c) The mounting angle of not only the first camera 11N but also the second camera 11D relative to the substrate 60 may be adjustable.

[0059] (d) First camera 11N and second camera 11D may have zoom lenses as lens unit 81 and lens unit 91, respectively, in which case "having a second focal length longer than the first focal length" means that the second focal length of second camera 11D can be adjusted so that it is longer than the first focal length of first camera 11N.

[0060] [Embodiment 2] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0061] Fig. 8 is a side view schematically illustrating the external configuration of the train 1 in embodiment 2. As shown in Fig. 8, the train 1 in this embodiment differs from embodiment 1 in that the first camera 11N and the second camera 11D are not housed in a single housing 5.

[0062] Specifically, the train 1 is provided with a first camera 11N and a second camera 11D, which are mounted on the side of the first end E1, facing the second end E2 of the train 1 and capture images of subjects boarding and disembarking through at least some of the multiple doors. The first camera 11N has a first optical axis AX1 and a first focal length, while the second camera 11D has a second optical axis AX2 and a second focal length longer than the first focal length. The angle θ20 formed by the second optical axis AX2 and the horizontal direction is smaller than the angle θ10 formed by the first optical axis AX1 and the horizontal direction. In FIG. 8, the direction of the line corresponding to the surface of the platform PF in a side view is considered to be the horizontal direction.

[0063] According to the above configuration, the first camera 11N, which has a relatively short focal length, can capture an image of an area close to the first end E1 of the train 1, and the second camera 11D, which has a relatively long focal length, can capture an image of an area far from the first end E1. Although the angle of view of the second camera 11D is narrower than that of the first camera 11N, by making the angle θ20 between the second optical axis AX2 and the horizontal direction smaller than the angle θ10 between the first optical axis AX1 and the horizontal direction, it is possible to fit a desired imaging range within the angle of view of the second camera 11D.

[0064] In this embodiment, the first camera 11N and the second camera 11D may be imaging devices (cameras) each having a separate housing. The first camera 11N and the second camera 11D may be adjacent to each other so as to face the same side, either the front or rear, with respect to the traveling direction D1 of the train 1, and may be installed in an arrangement in which the first optical axis AX1 and the second optical axis AX2 intersect. By installing the first camera 11N and the second camera 11D at the first end E1 of the train 1, it is possible to reduce the amount of equipment, such as wiring, required for installing the first camera 11N and the second camera 11D compared to installing multiple cameras at distant locations on the train 1.

[0065] In this embodiment, the train 1 includes a first vehicle V1 and a second vehicle V2, each of which has at least one door. The first camera 11N and the second camera 11D are provided on the first vehicle V1, and the second camera 11D captures images of subjects getting on and off through a door provided on the second vehicle V2.

[0066] According to the above configuration, it is possible to reduce the amount of equipment such as wiring required for installing the cameras compared to the case where first camera 11N is installed in first vehicle V1 and second camera 11D is installed in second vehicle V2.

[0067] [Embodiment 3] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0068] A monitoring system 300 according to this embodiment will be described with reference to FIGS. 9 and 10. FIG. 9 is a functional block diagram showing the configuration of the monitoring system 300. As shown in FIG. 9, the monitoring system (display system) 300 includes a monitor 120, a display control device 310, a storage unit 320, and a camera C. Here, the cameras C11 and C12 provided in the first vehicle V1 are collectively referred to as camera C. The monitoring system 300 may also include a transmission device 110 (see FIG. 1). The transmission device 110 is not shown in FIG. 9. The following description may also be applied to a monitoring system including cameras C21, C22, and a monitor 220 in the second vehicle V2.

[0069] The monitor 120 is a display device equipped with a display screen, such as a liquid crystal display device. The type of display device is not particularly limited. The monitor 120 displays images captured by the camera C. The camera C is equipped with a first camera 11N and a second camera 11D, and the monitor 120 displays images shown by the image data of the first camera 11N and the second camera 11D, respectively. By looking at the monitor 120, the driver can confirm the presence and behavior of passengers and animals (image subjects) such as assistance dogs (guide dogs) getting on and off through the doors of the first vehicle V1 or the second vehicle V2.

[0070] The imaging data acquired by first camera 11N and second camera 11D is transmitted via a communication cable (wiring) to display control device 310. Display control device 310 controls the display mode when the imaging data is displayed on monitor 120.

[0071] The storage unit 320 also stores (1) the control programs of each unit, (2) the OS program, (3) the application programs, and (4) various data read when these programs are executed by the display control device 310. The storage unit 320 is configured by a non-volatile storage device such as a hard disk or flash memory.

[0072] Fig. 10 is a diagram showing an example of the display screen of the monitor 120. As shown in Fig. 10, the monitor 120 displays, on the left side of the display screen of the monitor 120, an image IM1 captured by a first camera 11N provided on a camera C (referred to as the operating camera C) located on the platform PF side, which is located at a first end E1 on the forward side in the traveling direction D1 of the train 1. In the example shown in Fig. 1, the camera C11 is the operating camera C. Also, on the right side of the display screen of the monitor 120, an image IM2 captured by a second camera 11D provided on the operating camera C is displayed.

[0073] Which of the multiple cameras C is to be the operating camera C may be designated by the driver (crew member), or may be determined by the display control device 310 depending on the vehicle operating conditions. For example, a correspondence between vehicle position information and the camera C to be operated may be stored in advance in the storage unit 320, and the display control device 310 may identify the camera C to be operated based on the vehicle position information.

[0074] As described above, the monitoring system 300 in this embodiment is a system for monitoring the doors and their surroundings in a train 1 that is provided with a plurality of doors (doors 101-106, 201-206) for boarding and alighting. The monitoring system 300 includes a first camera 11N and a second camera 11D that are provided on the side of a first end E1 of a vehicle (for example, a first vehicle V1) and face a second end E2 of the vehicle to capture images of subjects getting on and off through at least some of the plurality of doors, and a display device (for example, a monitor 120) that displays images represented by the image data of the first camera 11N and the second camera 11D.

[0075] According to the above configuration, it is possible to reduce the amount of equipment such as wiring required for installing the first camera 11N and the second camera 11D compared to when multiple car-side cameras are installed at distant locations on the train 1. This makes it easier to build the monitoring system 300 on the train 1.

[0076] As mentioned above, the first camera 11N and the second camera 11D do not have to be housed in the housing 5, and the same effect as that described above can be achieved even if the first camera 11N and the second camera 11D are installed adjacent to each other on the side of the train 1 as separate imaging devices.

[0077] A vehicle (first vehicle V1 in the example shown in FIG. 8) on which the first camera 11N and the second camera 11D are installed is referred to as a specific vehicle. The monitor 120 is installed in the specific vehicle. In the monitoring system 300 of this embodiment, wiring connecting the first camera 11N and the second camera 11D to the monitor 120 may be installed only within the specific vehicle. In such a monitoring system 300, it is not necessary to install a communication cable for displaying information on the monitor 120, which is different from the control circuit in the train 1, between the first vehicle V1 and the second vehicle V2. This makes it possible to effectively simplify equipment such as wiring.

[0078] (Other configuration examples) Display control device 310 may display image IM1 from first camera 11N and image IM2 from second camera 11D at the same size, or may display image IM2 from second camera 11D larger than image IM1 from first camera 11N. Since second camera 11D is a camera that captures images at a relatively long distance, this display mode makes it easier to view the subject captured by second camera 11D.

[0079] [Additional notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0080] 1 train 11D Second Camera 11N 1st Camera Doors 101-106 AX1 1st optical axis AX2 2nd optical axis C11 Camera V1 1st vehicle V2 2nd vehicle

Claims

1. A binocular camera that captures images of subjects getting on and off through multiple doors on a train, a first camera having a first optical axis and a first focal length; a second camera having a second optical axis not parallel to the first optical axis and a second focal length longer than the first focal length; a substrate to which the first camera and the second camera are fixed, the first camera and the second camera are fixed to the substrate such that an acute angle between the first optical axis and the second optical axis is 10° or more and 45° or less in a plan view of the substrate; an angle of the first optical axis with respect to the second optical axis in a plan view can be adjusted by changing a fixed position of the first camera on the board; a first tilt angle is an angle of tilt of the first optical axis with respect to the substrate, the angle corresponding to an elevation angle when the substrate is regarded as a horizontal plane in the first camera; a second tilt angle is an angle of tilt of the second optical axis with respect to the substrate, the angle corresponding to an elevation angle when the substrate is regarded as a horizontal plane in the second camera; The first tilt angle is greater than the second tilt angle.

2. a housing including the substrate and accommodating the first camera and the second camera; the substrate has one or more holes penetrating from the front surface to the rear surface on the opposite side, The camera according to claim 1 , wherein a first cable connected to the first camera and a second cable connected to the second camera are inserted through the hole and drawn out to the outside of the housing.

3. A train equipped with multiple doors for boarding and alighting, a first camera and a second camera that are provided on a side surface at a first end of the train, facing a second end of the train, and capture images of subjects getting on and off through at least some of the plurality of doors; the first camera has a first optical axis and a first focal length; the second camera has a second optical axis and a second focal length that is longer than the first focal length; an angle formed between the second optical axis and a horizontal direction is smaller than an angle formed between the first optical axis and a horizontal direction; an imaging field of view of the first camera includes a first visual recognition area for imaging the imaging target getting on and off through each of the plurality of doors that is closer to the first end among the plurality of doors; The imaging field of view of the second camera includes a second viewing area that images subjects getting on and off through each of the plurality of doors that are closer to the second end than the first viewing area.

4. a first vehicle and a second vehicle each having at least one of the doors; the first camera and the second camera are provided in the first vehicle, The train according to claim 3 , wherein the second camera captures an image of an object getting on or off through the door of the second car.

5. A monitoring system for a train equipped with multiple doors for boarding and alighting, the train has a plurality of cars; a first camera and a second camera provided on a side surface at a first end of the vehicle, facing a second end of the vehicle, and configured to capture images of subjects getting in and out of the vehicle through at least some of the plurality of doors; a display device that displays images represented by the imaging data of the first camera and the second camera, the first camera has a first optical axis and a first focal length; the second camera has a second optical axis and a second focal length that is longer than the first focal length; an angle formed between the second optical axis and a horizontal direction is smaller than an angle formed between the first optical axis and a horizontal direction; an imaging field of view of the first camera includes a first visual recognition area for imaging the imaging target getting on and off through each of the plurality of doors that is closer to the first end among the plurality of doors; A surveillance system in which the imaging field of view of the second camera includes a second viewing area that images subjects getting on and off through each of the plurality of doors that are closer to the second end than the first viewing area.

6. the display device is installed in a specific vehicle, among the plurality of vehicles, in which the first camera and the second camera are provided; The surveillance system according to claim 5 , wherein wiring connecting the first camera and the second camera to the display device is provided only within the specific vehicle.

Images