WO2024195154A1 - Image system and imaging apparatus - Google Patents

Abstract

In the present invention, an image system comprises a camera for capturing images, and a display device for displaying the images captured by the camera. The camera has an imaging element for capturing images, and an image processing unit for processing the images captured by the imaging element. The image processing unit outputs a plurality of images having different capturing ranges.

Description

Image system and imaging device Incorporation by Reference

This application claims priority to Japanese Patent Application No. 2023-47049, filed on March 23, 2023, the contents of which are incorporated herein by reference.

The present invention relates to an imaging system.

IP-based CCTV systems encode images captured by IP cameras in H264/MPEG4/JPEG, etc., then decode the images received by a server, etc., and display the images on a monitor. Compared to analog CCTV systems, IP-based CCTV systems have the advantage of being able to select image resolution and frame rate, and being able to transfer multiple images over a single cable, simplifying wiring. For this reason, IP-based CCTV systems are used in on-board surveillance systems for railways, where installation space is limited. On-board surveillance systems are used to check the safety of multiple boarding and alighting entrances with surveillance cameras, in order to reduce the number of people required for train operations. For this reason, the display area of a single monitor is divided and surveillance images of multiple boarding and alighting entrances are displayed to check safety.

The following prior art is included as background technology in this technical field. For example, Patent Document 1 (JP 2018-113602 A) describes a surveillance system in which a camera that captures at least the vicinity of the doors of the cars that make up the train and a monitor that displays the camera images captured by the camera are mounted on the train, the camera is disposed for each of a number of doors provided on both sides of the cars, the display area of the monitor is divided into a number of areas, and a display control unit is provided that controls the allocation of the camera images to each area based on information indicating the direction in which the train is traveling and information indicating the side on which the door opens.

　In-vehicle surveillance systems use multiple cameras to capture surveillance images, but because each camera only outputs one image, nearby objects may be framed out of the field of view, or distant objects may be small and difficult to see. In particular, the display area of the surveillance monitor installed in the driver's seat is divided to display images of multiple boarding and alighting doors in each area, and passengers getting on and off near the doors when the vehicle is stopped are monitored.

However, a single-chip camera with a single image sensor is usually attached to the side of the vehicle, and when the vehicle is long or when monitoring multiple doors, objects close to the camera may be framed out of the field of view or distant objects may appear small, making it difficult to obtain the necessary information.

The present invention aims to provide an imaging system that can accurately monitor both areas close to the camera and areas far away.

A representative example of the invention disclosed in this application is as follows: An image system comprising a camera that captures images and a display device that displays the images captured by the camera, the camera having an image sensor that captures images and an image processing section that processes the images captured by the image sensor, the image processing section being characterized in that it outputs a number of images with different capture ranges.

In one example of the image system of the present invention, the camera has a plurality of the image sensors and a plurality of lenses provided in front of each of the plurality of image sensors, the plurality of lenses having different focal lengths so as to have different shooting ranges, and the image processing unit outputs a plurality of images having different angles of view captured by the plurality of image sensors.

In one example of the image system of the present invention, the display device displays multiple images output from the camera with different shooting ranges side by side.

In one example of the image system of the present invention, the display device selectively displays one of a number of images output from the camera and having different shooting ranges.

In one example of the image system of the present invention, the image processing unit is characterized in that it synthesizes multiple images with different shooting ranges into a single image and outputs the image.

An example of an imaging device according to the present invention is an imaging device that captures images, and includes an imaging element that captures images, and an image processing unit that processes the images captured by the imaging element, and the image processing unit is characterized in that it outputs multiple images with different capture ranges.

According to one aspect of the present invention, a camera outputs multiple images with different shooting ranges, allowing a wider shooting range of nearby subjects and allowing distant subjects to be captured in large size. Problems, configurations, and effects other than those described above will become clear from the following description of the embodiment of the invention.

1 is a diagram showing an overview of an image system according to an embodiment of the present invention; FIG. 1 is a diagram showing a configuration of an image system according to an embodiment of the present invention. FIG. 1 is a diagram illustrating a configuration of a camera according to an embodiment of the present invention. FIG. 1 is a diagram showing an image displayed on a surveillance monitor in a conventional imaging system. FIG. 1 is a diagram showing an image captured by a camera in a leading vehicle in a conventional image system. 1 is a diagram showing an image displayed on a surveillance monitor in the imaging system of the present embodiment. FIG. FIG. 2 is a diagram showing a telephoto image captured by a camera in a leading vehicle in the imaging system of the present embodiment. FIG. 2 is a diagram showing a wide-angle image captured by a camera in a leading vehicle in the image system of the present embodiment.

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an overview of an image system according to an embodiment of the present invention.

The image system of this embodiment is implemented in a three-car train consisting of a leading car 1, a middle car 2, and a trailing car 3.

Each of the leading car 1, middle car 2, and trailing car 3 has two doors 7-12 on one side, and passengers board and disembark through these doors 7-12. Cameras 4-6 are provided on the side of each of the cars 1-3 to monitor passengers boarding and disembarking through the doors 7-12. As shown in FIG. 1, in this embodiment, one camera is provided per car, and this one camera monitors passengers boarding and disembarking through the two doors. The cameras 4-6 are provided near the leading car of each car, but they may also be provided near the trailing car.

Surveillance monitors 13, 14 are provided in the driver's cabs of the leading car 1 and the trailing car 3. The surveillance monitors 13, 14 are display devices that display images captured by the cameras 4-6. The crew can check the images captured by the cameras 4-6 on the surveillance monitors 13, 14. In the example shown, passengers 31-35 are present on the platform where the train is stopped.

FIG. 2 shows the configuration of the image system in this embodiment.

The leading car 1 is equipped with an image server 19, a recording device 18, a higher-level server 20, a surveillance monitor 13, and a camera 4, and these devices are connected by a network device (e.g., an L2 switch) 15. The network connecting these devices may be configured as a wired network, or may be configured as a wireless network in part or in whole.

The image server 19 is a control device that performs image processing such as switching between images captured by the cameras 4 to 6 and displaying them on the surveillance monitors 13 and 14. The recording device 18 records the images captured by the cameras 4 to 6 on a non-volatile recording medium as needed. Crew members can display the images recorded on the recording device 18 by operating the operation panels provided on the surveillance monitors 13 and 14. The images recorded on the recording device 18 are used to identify the cause of any trouble that may occur.

The upper server 20 is a control device that controls the operation of the train. In this embodiment, the image server 19 obtains the train status (e.g., running status, door open/close status) from the upper server 20. For example, when the image server 19 receives a door open signal from the upper server 20, it controls the surveillance monitors 13 and 14 to display images of the doors. In addition, when the image server 19 receives a departure signal (over 5 km/h signal) from the upper server 20, it erases the images of the doors from the surveillance monitors 13 and 14.

The surveillance monitor 13 has a display unit that displays images captured by the cameras 4 to 6, and an operation unit for issuing instructions to the image server 19. The operation unit may be configured as a touch panel, and the operation unit and display unit may be configured as one unit. The surveillance monitor 13 is not limited to a display device provided in the driver's cab, and may be a portable terminal device carried by the crew.

Camera 4 is installed on the side of the leading car 1 and captures images of passengers getting on and off through two doors 7 and 8. The configuration of camera 4 will be described later with reference to Figure 3.

The rear vehicle 3 is equipped with a surveillance monitor 14 and a camera 6, and these devices are connected by a network device (e.g., an L2 switch) 17. The network connecting these devices may be configured as a wired network, or may be configured as a wireless network in part or in whole.

Surveillance monitor 14 has the same configuration as surveillance monitor 13, and includes a display unit that displays images captured by cameras 4 to 6, and an operation unit for issuing instructions to image server 19. The operation unit may be configured as a touch panel, and the operation unit and display unit may be integrated. Surveillance monitor 14 is not limited to a display device provided in the driver's cab, and may be a portable terminal device carried by the crew.

Camera 6 is installed on the side of the rear car 3 and captures images of passengers getting on and off through the two doors 11, 12. The configuration of camera 6 is the same as camera 4, and will be described later with reference to Figure 3.

A camera 5 is provided on the intermediate car 2, and the camera 5 is connected to a network device (e.g., an L2 switch) 16.

Camera 5 is installed on the side of intermediate car 2 and captures images of passengers getting on and off through two doors 9, 10. The configuration of camera 5 is the same as camera 4, and will be described later with reference to Figure 3.

Network devices 15, 16, and 17 are connected via communication path 50 to form an in-train network.

FIG. 3 is a diagram showing the configuration of camera 4 in this embodiment. Camera 4 will be described in FIG. 3, but cameras 5 and 6 have the same configuration.

In this embodiment, camera 4 is a two-chip camera that can output images via a network.

Camera 4 has two light receiving windows 81, 82, and inside each of the light receiving windows 81, 82 are lenses 83, 84 with different characteristics (e.g. different focal lengths). Lens 83 is a telephoto lens with a field of view in the range of 95 to 92, and captures door 8 at a long distance. Lens 84 is a wide-angle lens with a field of view in the range of 93 to 94, and captures door 7 at a close distance. Note that although lenses 83, 84 are illustrated as single convex lenses, in reality they are composed of a combination of multiple lenses.

Light focused by lens 83 enters image sensor 85, and light focused by lens 84 enters image sensor 86. Due to differences in focal length and optical axis direction between lenses 83 and 84, image sensor 85 and image sensor 86 capture images with different shooting ranges. Image sensors 85 and 86 generate raw image data (e.g., RAW data) through photoelectric conversion. Signal processors 87 and 88 perform signal processing such as noise removal and edge processing to clarify contours from the raw image data, and generate image data.

The image processing unit 89 cuts out the necessary areas from the image data generated by the signal processing units 87 and 88, or combines multiple images into one image, and inputs the generated image to the encoder unit 90. For example, it generates image 37 displayed in area 25 shown in FIG. 7, which is a cut-out of the area around the door, or image 38 displayed in area 26 shown in FIG. 8, or it combines images 37 and 38 to generate one image.

The encoder unit 90 converts the image data into a predetermined data format (e.g., JPEG/H.264) and outputs it to the network via the physical interface 91.

The image processing unit 89 receives image data from the signal processing unit 87 and image data from the signal processing unit 88, i.e., two images with different shooting ranges, and controls whether to output only the image from the signal processing unit 87, the image from the signal processing unit 88, or two images, depending on the user's operation on the surveillance monitors 13, 14. Furthermore, when outputting two images, the image processing unit 89 can select whether to output them as two independent images, or to combine the two images and output them as one image. Also, since the two images are output from the same address, it is advisable to assign different port numbers to the transmission of each output image. Also, door identification information can be added to each of the two image data so that it is possible to identify which door is shown in the image.

Although the example has been described in which cameras 4, 5, and 6 are two-chip cameras having two image sensors 85, 86, it is sufficient that cameras 4, 5, and 6 output images with different angles of view. For example, cameras 4, 5, and 6 may each have one high-resolution image sensor, generate multiple images with different shooting ranges (e.g., two images with different angles of view) from an image captured by that image sensor using digital zoom processing, and output the multiple images generated. Note that optical zoom, which moves the lens inside the lens barrel, cannot be used for in-vehicle image systems, since they are required to be vibration-resistant. Therefore, it is preferable to generate two images using digital zoom, rather than changing the magnification of the optical zoom to capture two images each.

In FIG. 3, the configuration of the camera 4 is illustrated according to the flow of the image signal, but the camera 4 has a control unit (logic and CPU) that is not illustrated. The control unit controls the operation of the image sensors 85 and 86, the signal processing units 87 and 88, the image processing unit 89, and the encoder unit 90.

In Fig. 3, a series including a lens 83, an image sensor 85, and a signal processor 87 and a series including a lens 84, an image sensor 86, and a signal processor 88 are arranged one above the other, but since the two series will be upside down when mounted on the opposite side of the vehicle, the two series may be arranged horizontally. Also, the camera 4 has a light receiving window 81 facing to the right and a light receiving window 82 facing diagonally downward to the right, but the positions of the light receiving windows can be adjusted as desired depending on the positions of the camera 4 and the door to be monitored.

In this way, the camera 4 outputs the two images acquired by the signal processing units 87 and 88 as one or two images.

The above describes camera 4, but cameras 5 and 6 have the same configuration. That is, camera 5 captures an image of door 10 at a long distance with lens 83, and captures an image of door 9 at a close distance with lens 84. Similarly, camera 6 captures an image of door 12 at a long distance with lens 83, and captures an image of door 11 at a close distance with lens 84.

Next, we will explain the images output by the imaging system of this embodiment, comparing them with images output by a conventional imaging system.

FIG. 4 is a diagram showing an image displayed on a monitor in a conventional imaging system, and FIG. 5 is a diagram showing an image captured by the camera in the leading car 1 in the conventional imaging system. Also, FIG. 6 is a diagram showing an image displayed on a monitor in the imaging system of this embodiment, FIG. 7 is a diagram showing a telephoto image captured by the camera 4 in the leading car 1 in the imaging system of this embodiment, and FIG. 8 is a diagram showing a wide-angle image captured by the camera 4 in the leading car 1 in the imaging system of this embodiment.

In conventional image systems, to monitor passengers getting on and off when the train stops at a station, images taken by each camera are displayed side by side on the monitor of the leading car 1 or the trailing car 3. The monitor screen is divided into three parts as shown in Figure 4, and image 21 taken by the camera of the leading car 1, image 22 taken by the camera of the middle car 2, and image 23 taken by the camera 6 of the trailing car are displayed side by side. Image 21 taken by the camera of the leading car 1 and displayed in the three-part image is image 36 taken by the camera of the leading car 1 shown in Figure 5, cropped by area 24.

In the situation shown in Figure 1, the image of leading car 1 displayed on the monitor of the conventional image system shows passengers 31 and 32 getting on through door 7, and passenger 33 getting on through door 8. The image of middle car 2 shows no passengers. The image of rear car 3 shows passenger 34 getting off through door 11, and passenger 35 getting off through door 12. However, the lower parts of passengers 31 and 32 near door 7, and passenger 34 near door 11, are in blind spots outside the image from the waist down. Furthermore, passenger 33 near door 8 and passenger 35 near door 12 are small and difficult to see.

On the other hand, in the image system of this embodiment, in order to monitor passengers getting on and off when the train stops at a station, the images taken by the cameras 4 to 6 are displayed side by side on the monitoring monitor 13 of the leading car 1 or the monitoring monitor 14 of the trailing car 3. The screen of the monitoring monitors 13 and 14 is divided into six parts as shown in FIG. 6, and a telephoto image 40 taken by the camera 4 of the leading car 1, a wide-angle image 41 taken by the camera 4 of the leading car 1, a telephoto image 42 taken by the camera 5 of the middle car 2, a wide-angle image 43 taken by the camera 5 of the middle car 2, a wide-angle image 44 taken by the camera 6 of the trailing car 3, and a telephoto image 45 taken by the camera 6 of the trailing car 3 are displayed side by side. The image 40 displayed on the six-split screen is a crop of the telephoto image 37 taken by the camera 4 of the leading car 1 shown in FIG. 7, cropped by the area 25, and the image 41 is a crop of the wide-angle image 38 taken by the camera 4 of the leading car 1 shown in FIG. 8, cropped by the area 26. In addition to the six-split image shown in FIG. 6, the surveillance monitors 13 and 14 can display one image selected by the driver's operation, as shown in FIG. 7 and FIG. 8.

Camera 4 cuts out image 37 in area 25 and image 28 in area 26, combines the two images into one image, and transfers it to surveillance monitors 13 and 14 via the network. The other cameras 5 and 6 process the images they capture in the same way, and transfer the combined image to surveillance monitors 13 and 14 via the network. Surveillance monitors 13 and 14 display the image shown in Figure 6 by arranging the three images received from cameras 4, 5 and 6. Note that while an example has been described in which cameras 4, 5 and 6 cut out images and surveillance monitors 13 and 14 combine images, surveillance monitors 13 and 14 may also perform the cutting and combining of images, or image server 19 may perform the cutting and combining of images.

In a conventional imaging system, as shown in FIG. 4, passengers 31 and 32 near door 7 and passenger 34 near door 11 are in blind spots that extend beyond the image from the waist down, but in the imaging system of this embodiment, as shown in FIG. 6, the entire bodies of passengers are captured, with almost no blind spots around the doors. Also, in a conventional imaging system, passengers 33 at door 8 and passenger 35 at door 12, who are far from the camera, are captured small, as shown in FIG. 4, but in the imaging system of this embodiment, they are displayed large and with sufficient resolution, as in images 40 and 44 shown in FIG. 6.

The above shows an example of applying the image system of the present invention to monitoring boarding and alighting from trains, but the present invention is not limited to monitoring boarding and alighting from trains and can be applied to other systems that display images from surveillance cameras on a multi-split screen.

For example, in a pantograph monitoring system that photographs the pantograph with a camera installed on the roof of a train, the wide-angle image of the camera captures the entire pantograph, and the telephoto image captures the contact strip that comes into contact with the overhead wire. This makes it possible to simultaneously monitor the operating state of the pantograph and the wear of the contact strip.

In addition, in a forward monitoring system that uses a camera installed at the front of the train (e.g., in the crew cabin) to capture the direction of travel, the camera's wide-angle image captures the coupling section of the cars, and the telephoto image captures the track in the direction of travel. This makes it possible to monitor the front of the train, the approaching state of trains when coupling and uncoupling, and the state of the coupling section with a single camera. Furthermore, by capturing the crew cabin (e.g., the driver's seat) with a wide-angle image from the camera and the track in the direction of travel with a telephoto image, it is possible to monitor the front of the train and the crew simultaneously, and to identify any abnormalities that occur to the crew.

In addition, in a passenger compartment monitoring system that uses a camera installed inside a train passenger compartment to capture images of the interior of the passenger compartment, the camera's wide-angle image captures the interior of the nearby passenger compartment, and the telephoto image captures the interior of the distant passenger compartment (for example, the end of the car). This allows a wide area inside the car to be captured with sufficient resolution. Furthermore, the camera's wide-angle image captures the interior of a nearby door, and the telephoto image captures the interior of a distant door. This allows passengers getting on and off at multiple doors to be monitored simultaneously.

As described above, according to the video system of the embodiment of the present invention, a close-up wide-angle image and a long-distance telephoto image are captured from the camera, making it possible to capture a wide range, including blind spots that would be outside the range of a monocular camera, and to capture large images of distant subjects. In addition, since multiple lenses and multiple image sensors are provided in one camera, close-up images and long-distance images are captured with different image sensors, making it possible to achieve both wide-angle capture of a wide range and telephoto capture of distant subjects.

The present invention is not limited to the above-described embodiments, but includes various modified examples and equivalent configurations within the spirit of the appended claims. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to having all of the configurations described. Furthermore, part of the configuration of one embodiment may be replaced with the configuration of another embodiment. Furthermore, the configuration of another embodiment may be added to the configuration of one embodiment. Furthermore, part of the configuration of each embodiment may be added, deleted, or replaced with other configurations.

Furthermore, each of the configurations, functions, processing units, processing means, etc. described above may be realized in part or in whole in hardware, for example by designing them as integrated circuits, or may be realized in software by a processor interpreting and executing a program that realizes each function.

Information such as programs, tables, and files that realize each function can be stored in a storage device such as a memory, hard disk, or SSD (Solid State Drive), or in a recording medium such as an IC card, SD card, or DVD.

Furthermore, the control lines and information lines shown are those considered necessary for explanation, and do not necessarily represent all control lines and information lines necessary for implementation. In reality, it is safe to assume that almost all components are interconnected.

Claims (7)

1. An imaging system comprising:
A camera for taking images;
a display device for displaying an image captured by the camera;
The camera includes an image sensor that captures an image, and an image processor that processes the image captured by the image sensor.
The image system according to the present invention is characterized in that the image processing unit outputs a plurality of images having different shooting ranges. 2. The imaging system of claim 1,
the camera includes a plurality of the imaging elements and a plurality of lenses provided in front of each of the imaging elements;
The plurality of lenses have different focal lengths so as to have different photographing ranges,
The image processing unit outputs a plurality of images captured by the plurality of image pickup elements, the images having different angles of view. 2. The imaging system of claim 1,
The image system is characterized in that the display device displays a plurality of images output from the camera with different shooting ranges side by side. 4. The imaging system of claim 3,
The image system is characterized in that the display device selectively displays one of a plurality of images having different shooting ranges output from the camera. 2. The imaging system of claim 1,
The image system according to the present invention, wherein the image processing unit synthesizes a plurality of images with different shooting ranges into a single image and outputs the single image. An imaging device for capturing an image,
An image sensor for capturing an image;
an image processing unit that processes an image captured by the imaging element,
The imaging device, wherein the image processing unit outputs a plurality of images having different shooting ranges. 7. The imaging device according to claim 6,
A plurality of the imaging elements;
a plurality of lenses provided in front of each of the plurality of image pickup elements;
The plurality of lenses have different focal lengths so as to have different photographing ranges,
The imaging device, wherein the image processing unit outputs a plurality of images having different angles of view captured by the plurality of imaging elements.

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