JP7757643B2 - Imaging device - Google Patents

Description

This disclosure relates to imaging devices, particularly imaging devices used for gas detection.

Gas plants, petrochemical plants, thermal power plants, steelmaking facilities, and other facilities handle large amounts of gas during operation. The risk of gas leaks at such facilities due to aging or operational errors is recognized, and development is underway on imaging devices that can capture and visualize gas in order to minimize gas leaks before they lead to major accidents (see, for example, Patent Document 1).

Such imaging devices used for gas detection are installed in multiple locations within large facilities, such as petrochemical plants, and image data is sent to a central monitoring room, where it is analyzed by a large computer to monitor for gas leaks. However, it can be difficult to install multiple imaging devices in every facility, and there is a demand for handheld imaging devices that can be carried by monitors to detect gas leaks in small areas that cannot be detected by fixed imaging devices.

International Publication No. 2017/073430

However, it is difficult to equip handheld imaging devices with large displays, making them less user-friendly. Furthermore, it is difficult to transmit image data to a central monitoring room using a wired connection with handheld imaging devices, so it is desirable to have an environment such as a wireless LAN. However, in situations where handheld imaging devices are expected to be useful, such as during disasters or accidents, it is anticipated that there may be times when the receiving device is unable to use wireless communication due to a power outage or other reasons.

For this reason, if the imaging device itself were to be equipped with more advanced image analysis options, it would need to be equipped with a more powerful CPU and a larger memory unit. Furthermore, power consumption would increase, requiring a larger battery capacity. This could lead to higher costs and a larger device, making it difficult to fully meet the demands of a handheld imaging device.

In light of the above circumstances, the present disclosure aims to provide an imaging device for gas detection that is easy to use and expandable, while ensuring portability and low cost as a handheld type, without adding unnecessary optional functions to the device itself.

An imaging device according to one aspect of the present disclosure is an imaging device used for gas detection, comprising: an image acquisition means for converting an incident target image through an optical lens into an electrical signal to acquire image data; and a communication means for establishing communication with an external portable terminal and transmitting the acquired image data. The imaging device is characterized in that the device housing has a holding means on the back side opposite to the front side on which the optical lens is disposed for detachably holding the external portable terminal , and a display unit on the side of the device housing for displaying an image based on the image data .

In another aspect of the present disclosure, the image acquisition means acquires the image data by converting the target image into an electrical signal using an infrared imaging element.

In another aspect of the present disclosure, the image acquisition means is characterized by including an image processing unit that processes the image data to generate image data in which the gas is visualized.

In another aspect of the present disclosure, the communication means includes a communication unit that establishes communication with the external mobile terminal via near-field wireless communication conforming to the NFC standard, and the communication unit is located within the device housing and within a communication range of the near-field wireless communication with the external mobile terminal held by the holding means.

In another aspect of the present disclosure, the communication means includes a communication unit that establishes communication with the external portable terminal via wired communication conforming to the USB standard, a USB male connector is disposed in the holding means, and when the external portable terminal is held in the holding means, the USB female connector of the external portable terminal is directly connected to the USB male connector.

In another aspect of the present disclosure, the external portable terminal has installed thereon a first program for analyzing the state of gas based on image data, and/or a second program for accessing a website on the Internet and using a web application on the website, and the communication means, after establishing communication with the external portable terminal, launches the first program to cause the external portable terminal to analyze the image data, or instructs the external portable terminal via the second program to analyze the image data using the web application.

In another aspect of the present disclosure, the external portable terminal includes a magnetic material, and the holding means includes a magnet, and the external portable terminal is held to the device housing by the magnetic force of the magnet.

In another aspect of the present disclosure, the holding means has a pair of gripping members whose distance from each other is adjustable, and by adjusting the distance between the pair of gripping members, it is possible to hold external portable devices of different sizes.

In another aspect of the present disclosure, the holding means is characterized by having an attitude change mechanism that can change the attitude of the external portable terminal.

In another aspect of the present disclosure, the holding means is detachable from the device housing.

In the above aspect, by establishing communication with the external mobile terminal using the communication means and transmitting image data acquired by the image acquisition means, it becomes possible to use the display unit of the external mobile terminal and utilize the processing power of the CPU of the external mobile terminal (improved scalability), thereby improving operability without particularly increasing the specifications of the imaging device itself, and suppressing increases in cost and size of the device. Furthermore, the external mobile terminal can be held in the housing of the imaging device by the holding means when connection is required, and can be handled as a single unit compared to when the external mobile terminal is held in a separate location, resulting in superior portability and convenience.

1A is an external view of an imaging device according to an embodiment of the present disclosure, and FIG. 1B is an external perspective view showing the imaging device when an external mobile terminal is mounted thereon. 2 is a block diagram showing the configuration of each control unit of the imaging device and the external mobile terminal. FIG. 10 is a flowchart showing a procedure of communication control performed on the imaging device side. 10 is a flowchart showing a procedure of communication control performed on the external mobile terminal side. FIG. 2 is a diagram illustrating a first configuration example of a terminal holding unit provided on the rear surface of the imaging device. 10A and 10B are diagrams illustrating a second configuration example of a terminal holding unit provided on the rear surface of the imaging device. 10A, 10B, and 10C are diagrams illustrating a third configuration example of a terminal holding unit provided on the rear surface of an imaging device.

<Embodiment>
Hereinafter, an imaging device according to an embodiment of the present disclosure will be described with reference to the drawings.

(1) Appearance of the Imaging Device FIG. 1(a) is an external view of the imaging device 10, and FIG. 1(b) is a perspective view showing the appearance when an external mobile terminal 20 is mounted on a terminal holding section 30 on the back side of the imaging device 10.

As shown in FIG. 1(a), a lens unit 101 is attached to the front of the housing 11 of the imaging device 10, and a handle 111 is formed on the top to make it easy for users such as security personnel to carry the device.

In addition, a display unit 105 consisting of a display device such as an LCD display or an organic EL display is provided on the side of the housing 11 to allow the imaging results to be viewed, and a terminal holding unit (holding means) 30 for holding an external mobile terminal 20 is provided on the rear of the housing 11 (the side opposite to the side on which the lens unit 101 of the device body is installed).

The terminal holding unit 30 has a clip 32 attached to its lower end, which is made of a resilient material such as resin. By clamping the lower end of the external mobile terminal 20 with the clip 32 while the back of the external mobile terminal 20 is leaning against a holding plate (backrest plate) 31 of the terminal holding unit 30, which is inclined toward the side where the lens unit 101 is installed, the external mobile terminal 20 can be held to the imaging device 10 and carried as a single unit.

(2) Control Systems of the Imaging Device and the External Portable Terminal FIG. 2 is a functional block diagram showing the control systems of the imaging device 10 and the external portable terminal 20. As shown in FIG.

(2-1) Control System of the Imaging Device The control system on the imaging device 10 side consists of a lens unit 101 equipped with an optical lens and a small motor for focus adjustment, an infrared imaging element 102 that converts the infrared image formed by the lens unit 101 into an image signal, an image processing unit 103 that generates visible image data, an image storage unit 104 that stores the image data generated by the image processing unit 103, a display unit 105 that displays an image of the detection target based on the image data stored in the image storage unit 104, a communication unit 109 for communicating with the external mobile terminal 20, a CPU 106, a RAM 107, and a ROM 108.

The CPU 106 reads the necessary programs from the ROM 108 and, using the RAM 107 as a work area, controls the operation of the lens unit 101, infrared imaging element 102, image processing unit 103, image storage unit 104, display unit 105, and communication unit 109 to detect the presence or absence of gas generation within the target imaging area.

In this embodiment, image data (raw data) is formed by the CPU 106 based on the electrical signal (image signal) obtained by the infrared imaging element 102, and is further processed in the image processing unit 103 to generate visible image data, which corresponds to the "image acquisition unit" in this invention.

In addition, in this embodiment, the infrared imaging element 102 detects infrared light with a wavelength of, for example, 3.2 to 3.4 μm, converts it into an electrical signal, and the image processing unit 103 processes this raw data to create a visible image, making it possible to detect hydrocarbon gases such as methane, ethane, ethylene, and propylene.

The image data visualized by the image processing unit 103 is stored in the image storage unit 104, and an image based on the image data is displayed on the display unit 105, allowing the monitor to visually check for the presence or absence of a gas leak within the area being photographed.

In this embodiment, the image processing unit 103 performs gas region visualization processing and the like based on the image signal from the infrared imaging element 102, and generates image data in which the gas present in the target region is visualized. Such gas region visualization processing is performed by extracting specific frequency components from the image signal, thereby visualizing regions in the gas image where temporal fluctuations exist, as described in Patent Document 1, for example.

The CPU 106 can determine the presence or absence of gas (gas detection) based on the visualized image data. The display unit 105 displays, for example, a visualized image of the gas along with text indicating the results of the gas detection.

Furthermore, under the control of the CPU 106, the communication unit 109 establishes communication with the external mobile terminal 20 held in the terminal holding unit 30, transmits image data to the external mobile terminal 20, and activates a specific image analysis program pre-installed on the external mobile terminal 20 to perform a detailed analysis of the image data.

(2-2) Control System on the External Mobile Terminal 20 Side The external mobile terminal 20 includes a tablet terminal, a smartphone, or the like, and is generally available on the market.

The control system of the external mobile terminal 20 includes a CPU 201, RAM 202, ROM 203, display unit 204, storage 205, and communication unit 206.

The CPU 201 reads the OS (operating system) and other programs from the ROM 203, or reads downloaded applications stored in the storage (memory) 205, and executes control using the RAM 202 as a work area, enabling it to perform basic operations as an external mobile terminal. It also communicates wirelessly with the imaging device 10 via the communication unit 206.

(3) Communication Control The procedure of communication control executed between the imaging device 10 and the external mobile terminal 20 will be described below.

(3-1) Communication Control on the Image Capturing Device 10 Side FIG. 3 is a flowchart showing an example of a procedure for communication control performed on the image capturing device 10 side.

For example, if a monitor operating the imaging device 10 notices that an image of gas is being displayed on the display unit 105 and feels that further detailed analysis is necessary for confirmation, the monitor turns on the external mobile terminal 20 in his or her possession and places it in the terminal holder 30 of the imaging device 10 (step S11).

The communication unit 109 of the imaging device 10 and the communication unit 206 of the external mobile terminal 20 each have a communication circuit (NFC circuit) that performs short-range wireless communication compliant with the NFC (Near Field Communication) standard. This allows the imaging device 10 to establish communication with the external mobile terminal 20 (step S12), and the imaging device 10 requests the external mobile terminal 20 to transmit information about the image analysis program installed on the external mobile terminal 20 (the name of the analysis program) (step S13). Note that because the communication distance of the NFC circuit is very short (approximately 10 cm), it is desirable to position the communication unit 109 as close as possible to the terminal holding unit 30 within the housing 11 of the imaging device 10 (within the communication distance).

When the imaging device 10 receives information about the analysis program from the external mobile terminal 20, it displays the information on the display unit 105, for example, as an icon (step S14).

The display unit 105 may, for example, consist of a liquid crystal display with a touch panel layered on top, allowing the user to select the program to run by touching the icon.

When the CPU 106 accepts the selection (step S15), it instructs the external mobile terminal 20 via the communication unit 109 to launch the selected analysis program (step S16), transfers the infrared image data to be analyzed (in this embodiment, raw data) to the external mobile terminal 20 (step S17), and terminates communication control.

(3-2) Communication Control on the External Mobile Terminal 20 Side FIG. 4 is a flowchart showing an example of a procedure for communication control performed on the external mobile terminal 20 side.

The communication unit 206 of the external mobile terminal 20 establishes communication with the imaging device 10 via short-range wireless communication compliant with the NFC standard (step S21), receives a request from the imaging device 10 to send information about the image analysis program installed on the external mobile terminal 20, and transmits the information to the imaging device 10 (step S22).

The user may, for example, access a specific website in advance to download the necessary analysis program onto the external mobile terminal 20, which is then installed in the storage 205.

In this embodiment, examples of the analysis programs installed include a gas leakage amount analysis program for estimating the amount of leaked gas, and a gas concentration analysis program for estimating the concentration of leaked gas (see storage 205 in Figure 2).

Then, an instruction to start the selected analysis program is received from the imaging device 10, the analysis program is started (step S23), infrared image data is received from the imaging device 10 (step S24), and the analysis program is executed on the image data (step S25).

For example, when a gas leakage analysis program is selected from the imaging device 10, multiple frames of images are received from the imaging device 10, for example, per second, and the changes in the gas image in each frame are analyzed to estimate the gas leakage amount (see, for example, JP 2019-568790 A).

The analysis results are then displayed on the display unit 204 of the external mobile terminal 20 (step S26).

The analysis results may also be transmitted to the imaging device 10 and displayed on its display unit 105, or may be stored in the image storage unit 104 in association with the image data that was analyzed.

By configuring it as described above, the analysis that should be performed by the imaging device 10 can be shared with the general-purpose external mobile terminal 20, allowing the imaging device 10's specifications to remain the same and processing content to be expanded without incurring any cost increases.

In addition, the external mobile terminal 20 is held by the terminal holding section 30 on the rear surface of the housing 11 of the imaging device 10, allowing them to be carried as a single unit, providing excellent convenience.

Note that the display unit 204 of the external mobile terminal 20 is typically configured by laminating a touch panel on the surface of a display device, so convenience can be further improved by displaying the operation buttons (icons) required to operate the imaging device 10 on the display unit 204 of the external mobile terminal 20 and enabling them to be operated by the user's touch.

<<Variations>>
The present disclosure is not limited to the scope disclosed in the above embodiment, and for example, the following modified examples are also possible.

(1) In the above embodiment, communication between the imaging device 10 and the external mobile terminal 20 uses wireless communication conforming to the NFC standard. However, other communication standards, such as Bluetooth (registered trademark), may also be used. Furthermore, for example, the communication unit 109 of the imaging device 10 may be equipped with a Wi-Fi router function, and configured to communicate using a wireless LAN communication standard such as IEEE 802.11ac.

Alternatively, after first establishing communication using the NFC standard, image data may be transmitted using communication standards such as Bluetooth (registered trademark) or Wi-Fi.

It is also possible to configure the imaging device 10 and the external mobile terminal 20 to communicate via a wired connection. For example, wired communication may be configured based on the USB (Universal Serial Bus) standard. In this case, the imaging device 10 and the external mobile terminal 20 may be connected via a USB cord. Also, since the external mobile terminal 20 is typically provided with a female USB connector, for example, a male connector could be provided on the base portion 34 (Figure 5) of the terminal holding portion 30 of the imaging device 10, and when the external mobile terminal 20 is mounted on the imaging device 10, both the female and male connectors could be connected at the same time, providing greater operability.

(2) In the above embodiment, we have described a so-called infrared camera that acquires image data by converting a target image into an infrared image signal using the infrared imaging element 102. However, this is not limited to this, and any imaging device capable of detecting the gas being monitored may be used. For example, if the target being monitored is a gas that can be detected with visible light, such as white smoke-like water vapor, a general visible light camera may be used. Furthermore, the method for detecting a gas region is not limited to the above, and any process capable of detecting a gas region may be used.

(3) In the above embodiment, a specific website is accessed from the external mobile terminal 20, and the necessary analysis program (first program) is downloaded to the external mobile terminal 20 in advance and installed in the storage 205. An instruction to start a specified program is received from the imaging device 10, and the analysis program is started and executed on the image data in the external mobile terminal 20.

However, this is not a limitation, and in an environment where the Internet can be used wirelessly, it is also possible to use a web application to analyze image data.

For example, a web server on the Internet may be accessed via a specific browser (second program) installed on the external mobile terminal 20, and the desired application (web application) may be run on the web server to analyze the image data. At this time, the image data to be analyzed is sent to the web server. The external mobile terminal 20 receives the analysis results from the web application from the web server and displays them on the display unit 204 or sends them to the imaging device 10.

However, if a web application is embedded in the homepage of a website opened in a browser, the image data can be analyzed on the external mobile terminal 20, so there is no need to send the image data to a web server.

(4) In the above embodiment, the terminal holding unit 30 is configured by a holding plate 31 and a clip 32 arranged on the back surface of the housing 11 of the imaging device 10. However, in the case of an external mobile terminal 20 having a housing or a magnetic body inside, as shown in FIG. 5, a base 34 may be provided at the bottom end of the terminal holding unit 30 and a magnet 331 may be arranged on the holding plate 33. If the magnetic force of the magnet 331 is strong, the base 34 is not necessarily required.

The terminal holding unit 30 may also be configured to hold the external mobile terminal 20 so that its position can be changed relative to the imaging device 10.

For example, as shown in FIG. 6(a), a holding plate 35 having a clip 32 at its lower end may be attached to the rear surface of the housing 11 of the imaging device 10 via a ball joint 36 so that its position can be changed.

The ball joint 36 consists of a ball member 38 arranged on the back surface of the holding plate 35, and a holder member 37 arranged on the back surface of the housing 11, with a spherical inner surface that fits and holds the ball member 38. This allows the holding plate 35 to change its position within a specified angular range relative to the imaging device 10, allowing the user to tilt the external mobile terminal 20 to an angle that is easy to view.

In addition, by forming the ball holding portion 37 from a flexible material such as resin, it is possible to remove the ball member 38 from the ball holding portion 37 and separate the holding plate 35 from the imaging device 10, as shown in Figure 6(b).

The configuration that allows the position of the holding plate 35 to be changed relative to the housing 11 of the imaging device 10 and the configuration that allows the holding plate 35 to be removed from the housing 11 are not limited to the configuration shown in Figure 6.

Also, as shown in Figure 7(a), the terminal holding unit 30 may be configured to hold the external mobile terminal 21 from the left and right using a pair of gripping members 181, 182.

The gripping members 181 and 182 are biased toward each other, making it possible to hold external mobile devices 22 of different sizes, as shown in Figure 7(b).

Figure 7(c) is a schematic diagram showing an example of a terminal holding unit 30 in which the distance between the gripping members 181 and 182 is variable.

The gripping members 181, 182 are held by racks 183, 184 on the rear surface of the housing 11 so that they can slide horizontally, and the gripping members 181, 182 are attached to the outer ends of each rack 183, 184 so that they are perpendicular to the sliding direction.

The teeth of racks 183 and 184 face each other and mesh with the same pinion 185 from above and below. The shaft 186 of pinion 185 is biased to rotate in direction G in Figure 7(c) by a power spring (not shown) or the like, which biases racks 183 and 184 in directions H1 and H2, respectively, bringing gripping members 181 and 182 closer together. By increasing the distance between these paired gripping members 181 and 182, external portable terminals 20 of various sizes can be easily held.

In this modified example, the gripping members 181, 182 may be configured to be spread apart in the vertical direction. It is also possible to apply a load torque to prevent the shaft 186 of the pinion 185 from rotating easily, in which case the spiral spring is not necessarily required.

(5) When capturing images of the same imaging area for a certain period of time, and always using the imaging device 10 attached to the head of a tripod, for example, in the structure of the terminal holder 30 shown in Figure 5, the external mobile terminal 20 may be held by only the holding plate 33 inclined toward the lens unit 101 and the base 34. In such cases, a holder such as a magnet 331 (clip 32 in Figure 1(a)) is not necessarily required.

<Additional Information>
While the imaging device according to the present disclosure has been described above based on the embodiments and modifications, the present disclosure is not limited to the above-described embodiments and modifications. The present disclosure also includes forms obtained by applying various modifications to the above-described embodiments and modifications that would occur to a person skilled in the art, and forms realized by arbitrarily combining the components and functions of the embodiments and modifications within the scope of the present disclosure.

The imaging device disclosed herein is useful as an imaging device for gas detection that is highly operable and expandable while maintaining portability.

REFERENCE SIGNS LIST 10 Imaging device 11 Device housing 101 Lens unit 102 Infrared imaging element 103 Image processing unit 104 Image storage unit 105 Display unit 106 CPU
107 RAM
108 ROM
109 Communication unit 20, 21, 22 External portable terminal 201 CPU
202 RAM
203 ROM
204 Display unit 205 Storage 206 Communication unit 30 Terminal holding unit 31, 33, 35 Holding plate 32 Clip 34 Base unit 36 Ball joint 37 Ball holding unit 38 Ball member 181, 182 Grip member 183, 184 Rack 185 Pinion 186 Shaft

Claims (10)

An imaging device for use in gas detection, comprising:
an image acquisition means for converting an incident target image via an optical lens into an electrical signal to acquire image data;
a communication means for establishing communication with an external mobile terminal and transmitting the acquired image data;
An imaging device characterized in that the device housing has a holding means for detachably holding the external mobile terminal on the back side opposite the front side on which the optical lens is arranged, and a display unit for displaying an image based on the image data is provided on the side of the device housing. 2. The imaging device according to claim 1, wherein the image acquisition means acquires the image data by converting the target image into an electrical signal using an infrared imaging element. The imaging device described in claim 2, characterized in that the image acquisition means includes an image processing unit that processes the image data to generate image data in which the gas is visualized. 4. The imaging device according to claim 1, wherein the communication means includes a communication unit that establishes communication with the external portable terminal via near-field wireless communication conforming to the NFC standard, and the communication unit is located within a device housing and within a communication range of the near-field wireless communication with the external portable terminal held by the holding means. 4. The imaging device according to claim 1, wherein the communication means includes a communication unit that establishes communication with the external portable terminal via wired communication conforming to the USB standard, a USB male connector is disposed on the holding means, and when the external portable terminal is held on the holding means, a USB female connector of the external portable terminal is directly connected to the USB male connector. a first program for analyzing a state of gas based on image data is installed on the external portable terminal, and/or a second program for accessing a website on the Internet and using a web application on the website is installed on the external portable terminal;
The imaging device of any one of claims 1 to 5, characterized in that after establishing communication with the external portable terminal, the communication means either launches the first program to cause the external portable terminal to analyze the image data, or instructs the external portable terminal to analyze the image data using the web application via the second program. The imaging device according to any one of claims 1 to 6, characterized in that the external portable terminal includes a magnetic material and the holding means includes a magnet, and the external portable terminal is held in the device housing by the magnetic force of the magnet. The imaging device according to any one of claims 1 to 6, characterized in that the holding means has a pair of gripping members whose distance from each other is changeable, and by changing the distance between the pair of gripping members, it is possible to hold external portable terminals of different sizes. 9. The imaging device according to claim 1, wherein the holding means has an attitude changing mechanism that can change the attitude of the external portable terminal. 10. The imaging device according to claim 1, wherein the holding means is detachable from the device housing.