Sensor unit and detection device

Abstract

The present invention provides a simple battery-powered sensor unit and a detection device equipped therewith. [Solution] The sensor unit that transmits data to a terminal via a mobile communication system is located inside an arbitrary region and comprises an image sensor that acquires imaging signals from inside the region at regular intervals, a transmitting unit that transmits the imaging signals to the terminal, and a battery that drives the image sensor and the transmitting unit. The image sensor has an effective pixel count of 54 x 54 pixels or less.

Description

Technical Field

[0001] The present invention relates to a sensor unit and a detection device.

Background Art

[0002] Patent Document 1 discloses a refrigerator capable of imaging a storage room or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the invention described in Patent Document 1 needs to obtain power from a power plug electrically connected to a commercial power supply, it cannot be used in places where it cannot be connected to a commercial power supply.

[0005] The present invention has been made in view of such circumstances, and an object thereof is to provide a simple sensor unit capable of being battery-driven and a detection device provided with the same.

Means for Solving the Problems

[0006] In order to solve the above problems, a sensor unit according to the present invention is, for example, a sensor unit that transmits data to a terminal via a mobile communication system, is provided inside an arbitrary region, and an image sensor that acquires an imaging signal inside the region at regular intervals, a transmission unit that transmits the imaging signal to the terminal, and a battery that drives the image sensor and the transmission unit, and the image sensor is characterized in that the number of effective pixels is 54×54 pixels or less. The system includes an image processing unit that generates an image from the imaging signal, and the transmission unit may transmit the image generated by the image processing unit to the terminal.

[0007] To solve the above problems, the detection device according to the present invention is, for example, a sensor unit that transmits at least an image to a terminal via a mobile communication system, and comprises an image sensor provided inside an arbitrary region and acquiring imaging signals from inside the region at regular intervals, and a battery that drives the image sensor, and a processing unit connected to the sensor unit and acquiring the imaging signals, wherein the processing unit comprises an image processing unit that generates an image from the imaging signals and a transmission unit that transmits data to the terminal via a mobile communication system, the image sensor having an effective pixel count of 54 × 54 pixels or less, and the transmission unit transmits the image generated by the image processing unit to the terminal.

[0008] According to the above configuration, the sensor unit has a minimal configuration, and by reducing the number of effective pixels of the image sensor, power consumption is reduced, and the sensor unit can be powered by a battery. Therefore, the sensor unit is easy to install.

[0009] The processing unit includes a detection unit that detects whether or not there is a change in the image generated by the image processing unit, and the transmission unit may transmit the detection result of the detection unit to the terminal. This allows the terminal to grasp changes within the area (increase or decrease in objects or people).

[0010] The detection unit may detect whether there is a change in two images generated by the image processing unit based on two image signals acquired consecutively by the image sensor (for example, motion detection or object tracking). This enables monitoring and detection of the elderly, pedestrian flow detection, and determination of operating status. The detection unit may also detect whether there is a change in the image at a first time point compared to a background image at a second time point prior to the first time point (for example, object detection). This enables security devices (human detection) and detection of residual objects.

[0011] The detection unit may also detect, when there is a change in the image, the ratio of the number of pixels that have changed out of the total number of pixels used to acquire the imaging signal. This makes it possible to understand the proportion of objects and other elements that occupy the area and the degree of congestion.

[0012] The aforementioned region is a space enclosed by a housing with a door formed on its side, and the image sensor is located inside the housing, on the top or side of the housing, and the range in which the image sensor acquires the imaging signal may include the bottom of the housing. This allows a terminal located away from the housing to check whether or not packages or mail have arrived inside a housing such as a delivery box or mailbox. For example, it is possible to check the status of a mailbox on the first floor from an upper floor, or to check inventory in a distant warehouse, reducing the effort of travel.

[0013] The aforementioned area is an exhibition booth constructed by combining rod-shaped or plate-shaped members, and the exhibition booth may be equipped with multiple image sensors. This makes it possible to understand pedestrian flow and congestion levels from a terminal located away from the exhibition booth. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a simple sensor unit that can be powered by a battery and a detection device equipped therewith. [Brief explanation of the drawing]

[0015] [Figure 1] It is a diagram showing an overview of the sensor unit 1. [Figure 2] It is a block diagram showing the electrical configuration of the sensor unit 1. [Figure 3] It is a block diagram showing an overview of the electrical configuration of the sensor unit 1A. [Figure 4] It is a diagram showing an overview of the detection device 3. [Figure 5] It is a block diagram schematically showing an example of the hardware configuration of the processing unit 2. [Figure 6] It is a block diagram showing an overview of the electrical configuration of the detection device 3. [Figure 7] It is a block diagram showing an overview of the electrical configuration of the detection device 3A. [Figure 8] It is a diagram showing an overview of the sensor unit 1. [Figure 9] It is a diagram showing an overview of the detection device 3B. [Figure 10] It is a block diagram showing an overview of the electrical configuration of the detection device 3B. [Figure 11] It is a block diagram showing an overview of the electrical configuration of the detection device 3C.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of a sensor unit and a detection device, which are examples of the present invention, will be described in detail with reference to the drawings.

[0017] <First Embodiment> FIG. 1 is a diagram showing an overview of a sensor unit 1 which is an example of the present invention. The sensor unit 1 is a device for detecting an object in a container such as a delivery box or a mailbox. In the present embodiment, the sensor unit 1 is provided inside a delivery box.

[0018] The delivery box has a housing 100. The housing 100 has a door 101 formed on the side, a top surface 102, a bottom surface 103, and multiple sides. The sensor unit 1 is located inside the housing 100 and on the top surface 102. The sensor unit 1 does not have to be located on the top surface 102; it may also be located on the side surface 104.

[0019] The sensor unit 1 has a substrate 31 on which an image sensor 21 (see Figure 2) is provided. The image sensor 21 acquires imaging signals from inside the housing 100 (corresponding to any region of the present invention) at regular intervals.

[0020] The area in which the image sensor 21 acquires the imaging signal includes the bottom surface 103 of the housing 100. However, the area in which the image sensor 21 acquires the imaging signal may include not only the bottom surface 103 but also a part of the side surface 104.

[0021] The sensor unit 1 is connected to a wireless communication system N. The wireless communication system N is, for example, a mobile communication system such as the 4th generation mobile communication system (4G) or 5th generation mobile communication system (5G) as defined by 3GPP, or an LPWA (Low Power Wide Area) wireless communication (non-cellular LPWA) or cellular LPWA using the sub-gigahertz band (e.g., the 920 MHz band). The sensor unit 1 sequentially transmits the acquired imaging signals to the terminal 35 via the wireless communication system N. The terminal 35 may be a portable terminal or a stationary terminal, but in this embodiment, a portable terminal such as a tablet is used as the terminal 35.

[0022] Figure 2 is a block diagram illustrating the schematic electrical configuration of the sensor unit 1. The sensor unit 1 mainly consists of an image sensor 21, a transmitter 22, and a battery 23.

[0023] The image sensor 21 is a sensor that acquires an imaging signal by converting light incident on the light-receiving surface into an electrical signal (photoelectric conversion) and sequentially reading out the converted signal. The image sensor 21 includes, for example, a microlens for focusing light, a photodiode for performing photoelectric conversion, and a circuit for processing electric charge. The image sensor 21 can be a CMOS sensor, a CCD sensor, or the like.

[0024] A key feature of this invention is the small number of pixels used to acquire the imaging signal. For example, one method involves using an image sensor 21 with a small number of effective pixels. In this embodiment, the effective number of pixels of the image sensor 21 is 54 × 54 pixels. However, the effective number of pixels of the image sensor 21 is not limited to 54 × 54 pixels, but can be 54 × 54 pixels or less. For example, the effective number of pixels of the image sensor 21 may be 35 × 35 pixels or 36 × 16 pixels.

[0025] Furthermore, the method for reducing the number of pixels used to acquire the imaging signal is not limited to using an image sensor 21 with a small number of effective pixels. The number of pixels used to acquire the imaging signal can be reduced (54 x 54 pixels or less) by using only a portion of the pixels of the image sensor 21 through cropping, which reads only a portion of the area of ​​the image sensor 21, or by using decimation readout, which removes some lines when reading data from the image sensor 21, or by treating multiple pixels as one pixel through binning (pixel mixing). For example, an image sensor 21 with 100 x 100 effective pixels can be used, and the imaging signal can be acquired by limiting it to 50 x 50 pixels through cropping.

[0026] The image sensor 21 acquires an imaging signal at regular intervals. For example, the image sensor 21 may acquire a video imaging signal. The video frame rate is arbitrary, but a lower frame rate is preferable considering that it is powered by the battery 23. For example, in this embodiment, the frame rate is 20fps. However, the frame rate is not limited to this and may be set to any frame rate of 20fps or less as appropriate.

[0027] Furthermore, it is desirable for the image sensor 21 to have a wide field of view in order to acquire an image signal that includes the periphery and part of the side of the bottom surface 103. For example, the field of view of the image sensor 21 is 70°. However, the field of view of the image sensor 21 is not limited to 70°; for example, it could be 72° or 88°.

[0028] The transmitting unit 22 is a functional unit that transmits the imaging signal acquired by the image sensor 21 to the terminal 35 via the wireless communication system N. The transmitting unit 22 can use a known communication interface, such as an antenna.

[0029] The battery 23 is a power source that drives the image sensor 21 and the transmitter 22. The battery 23 may be, for example, a dry cell battery or a rechargeable battery.

[0030] The following describes the functions of the sensor unit 1. When the image sensor 21 acquires an imaging signal, the transmission unit 22 transmits the imaging signal to the terminal 35 via the wireless communication system N. The terminal 35 then converts the imaging signal into an image using an image processing unit (not shown) and displays the image on the display unit 35a (see Figure 1) of the terminal 35. This allows the user of the terminal 35 to view the image captured by the sensor unit 1 at any stage.

[0031] This process is performed each time the image sensor 21 acquires an imaging signal. As a result, the user using the terminal 35 can check whether or not a package has arrived inside the delivery box housing 100 without having to move near the delivery box.

[0032] According to this embodiment, by using a simple configuration consisting of an image sensor 21 and a transmission unit 22, the sensor unit 1 can be battery-powered. Furthermore, by reducing the number of effective pixels of the image sensor 21, power consumption is reduced, decreasing the frequency of battery replacement for the sensor unit 1's battery 23 and improving maintainability. In addition, because of its simple configuration, the sensor unit can be provided quickly and inexpensively.

[0033] Furthermore, according to this embodiment, since the image sensor 21 has a small number of effective pixels, i.e., a small amount of data, image data can be transmitted using a mobile communication system. For example, in regions or countries where the development of mobile communication system infrastructure is lagging, there may be environments where only outdated mobile communication systems are available, but real-time image confirmation is possible even in such regions.

[0034] Furthermore, according to this embodiment, by simply installing the sensor unit 1 on the housing 100 of the delivery box, it is possible to check on a handheld terminal whether or not a package has arrived in the delivery box. High-precision images are not required to check whether or not there is a package in the delivery box, and the sensor unit 1, which is easy to install and requires virtually no maintenance, is suitable for use in such applications. For example, the sensor unit 1 can be retrofitted to delivery boxes that are already installed in apartment buildings, etc., without any construction work.

[0035] By using sensor unit 1, there is no need to go to a delivery box or post box to check for mail or other items, and this will meet the expectations of the aging society in the future.

[0036] Furthermore, according to this embodiment, the wide field of view allows for greater flexibility in the mounting location of the sensor unit 1, resulting in improved usability. In addition, because the wide field of view allows for a general understanding of the situation from a rough image, a single sensor unit 1 can handle situations that previously required multiple sensors.

[0037] Furthermore, sensor unit 1 can also be applied to inventory shelves, etc. In this case, inventory can be checked from a location away from the shelves. In addition, since it is possible to roughly check whether inventory is present or not, it is useful for security measures.

[0038] Furthermore, in this embodiment, the image sensor 21 acquired a video signal, but the method of acquiring images at regular intervals is not limited to this. For example, the image sensor 21 may acquire a still image signal at predetermined intervals (for example, every 10 seconds). Also, the interval (frame rate, etc.) at which the image sensor 21 acquires images may be determined according to the amount of light (ambient brightness) input to the image sensor 21.

[0039] In this embodiment, the sensor unit 1 continuously acquires imaging signals, but the period during which the sensor unit 1 acquires imaging signals is not limited to this, and the sensor unit 1 may acquire imaging signals only for any period of time. For example, a sensor that detects the opening and closing of the door 101 may be installed on the door 101, and when the sensor detects that the door 101 has opened, imaging may be started by the image sensor 21. Alternatively, imaging by the image sensor 21 may be stopped after a predetermined period (for example, 5 minutes) has elapsed after the sensor detects that the door 101 has opened.

[0040] <Modified form of the first embodiment> The following describes a modified sensor unit 1A. Parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0041] Figure 3 is a block diagram illustrating the schematic electrical configuration of a modified sensor unit 1A. The sensor unit 1A is connected to a wireless communication system N and mainly comprises an image sensor 21, a transmitter 22, a battery 23, and an image processing unit 24.

[0042] The image processing unit 24 is a functional unit that generates an image from the electrical signal (imaging signal) read from the image sensor 21. The image processing unit 24 can utilize various already known technologies. The transmission unit 22 transmits the image generated by the image processing unit 24 to the terminal 35 via the wireless communication system N.

[0043] The following describes the functions of the sensor unit 1A. When the image sensor 21 acquires an imaging signal, the image processing unit 24 generates an image from the imaging signal, and the transmission unit 22 transmits the generated image to the terminal 35 via the wireless communication system N. This allows the user using the terminal 35 to view the image transmitted from the sensor unit 1 at any stage.

[0044] <Second Embodiment> The detection device 3 according to the second embodiment will be described below. Parts identical to those in the first embodiment and its modified form are denoted by the same reference numerals, and their descriptions are omitted.

[0045] Figure 4 shows a schematic diagram of the detection device 3, including the sensor unit 1B. The detection device 3 mainly consists of the sensor unit 1B installed inside the delivery box and the processing unit 2 connected to the sensor unit 1B wirelessly or by wire.

[0046] The processing unit 2 has a circuit board 32 on which a CPU 51 (see Figure 5) is mounted. The sensor unit 1B and the processing unit 2 are connected to each other by a wired connection via a cable, or by short-range wireless communication such as Wi-Fi (registered trademark) or Bluetooth (registered trademark). In this embodiment, the sensor unit 1B and the processing unit 2 are connected via a cable. The processing unit 2 is connected to the wireless communication system N.

[0047] Figure 5 is a schematic block diagram showing an example of the hardware configuration of the processing unit 2. The processing unit 2 includes a CPU (Central Processing Unit) 51, RAM (Random Access Memory) 52, ROM (Read Only Memory) 53, and a communication interface (I / F) 54.

[0048] The CPU 51 operates based on programs stored in the RAM 52 and ROM 53, and controls each component. The RAM 52 is volatile memory. The ROM 53 is non-volatile memory that stores various control programs, setting values ​​(for example, the interval for acquiring imaging signals), etc. The CPU 51 operates based on programs stored in the RAM 52 and ROM 53, and controls each component. The ROM 53 also stores the boot program that the CPU 51 runs when the sensor unit 1 is started, and programs that depend on the hardware of the sensor unit 1. The RAM 52 also stores programs executed by the CPU 51 and data used by the CPU 51.

[0049] The communication interface 54 receives data from other devices via the wireless communication system N and transmits it to the CPU 51, and also transmits data generated by the CPU 51 to other devices via the wireless communication system N.

[0050] The programs that implement each function are, for example, read from a storage medium or acquired via the wireless communication system N, installed in the sensor unit 1 via RAM 52, and executed by the CPU 51.

[0051] The CPU 51 has the function of a control unit 51a that controls each part of the sensor unit 1 based on input signals. The control unit 51a is constructed by executing a predetermined program read by the CPU 51. The control unit 51a can store data including imaging signals acquired by the image sensor 21 in a RAM 52 or the like, and retrieve data from the RAM 52 or the like.

[0052] The configuration of the processing unit 2 shown in Figure 2 is intended to illustrate the main configuration for explaining the features of this embodiment, and does not exclude configurations that are typically found in general information processing devices. For example, the processing unit 2 may have an input / output interface (I / F), a media interface (I / F), etc. The media interface reads programs or data stored on a storage medium such as an IC card or SD card and stores them in the RAM 52. Furthermore, the components of the processing unit 2 may be further classified into many components depending on the processing content, or one component may execute the processing of multiple components.

[0053] Figure 6 is a block diagram illustrating the schematic electrical configuration of the detection device 3. Sensor unit 1B mainly comprises an image sensor 21 and a battery 23. Processing unit 2 mainly comprises an image processing unit 24 and a transmission unit 22. Power can be supplied to processing unit 2 using various methods, such as a battery or wiring connectors.

[0054] The functions of the detection device 3 are described below. When the image sensor 21 acquires an imaging signal, the processing unit 2 acquires the imaging signal via the cable. The image processing unit 24 converts the imaging signal into an image, and the transmission unit 22 transmits the converted image to the terminal 35 via the wireless communication system N. As a result, the terminal 35 can display the image on the display unit 35a.

[0055] This process is performed each time the image sensor 21 acquires an imaging signal. As a result, the user using the terminal 35 can view the image captured by the sensor unit 1 in real time.

[0056] According to this embodiment, by simply installing the sensor unit 1B in the housing 100 of the delivery box, it is possible to check whether or not a package has arrived in the delivery box using a handheld terminal 35. In particular, by removing components other than the image sensor 21 and battery 23 from the sensor unit 1B and providing them in the processing unit 2, the frequency of replacing the battery 23 of the sensor unit 1B can be reduced, improving maintainability.

[0057] In this embodiment, the sensor unit 1B has an image sensor 21, but the sensor unit 1B may also have a light sensor or a light-emitting part such as an LED. The light sensor and light-emitting part are powered by electricity supplied from the battery 23, similar to the image sensor 21. For example, when the processing unit 2 receives an instruction from the terminal 35, it may light up the light-emitting part and acquire an imaging signal with the image sensor 21. This allows for clear confirmation of the image inside the housing 100. The light-emitting part may emit white light or infrared light.

[0058] <Modified form of the second embodiment> The following describes a modified detection device 3A. Note that parts identical to those in the first embodiment, its modified form, and the second embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0059] Figure 7 is a block diagram showing a schematic electrical configuration of a modified detection device 3A. The detection device 3A mainly comprises a sensor unit 1B and a processing unit 2A. The processing unit 2A mainly comprises an image processing unit 24, a transmission unit 22, and a detection unit 27.

[0060] The detection unit 27 is a functional unit that detects whether or not there is a change in the image generated by the image processing unit 24 based on the imaging signal acquired by the sensor unit 1B, i.e., the image sensor 21. For example, the detection unit 27 detects whether or not there is a change in the image acquired by the image sensor 21 by detecting whether or not there is a change in two consecutively acquired images.

[0061] Alternatively, the detection unit 27 detects whether there is a change in the image by detecting whether the image at any given time (corresponding to the first time in this invention) has changed compared to the background image. Here, the background image is an image generated by the image processing unit 24 based on the imaging signal acquired by the image sensor 21 at a time prior to any given time (corresponding to the second time in this invention), for example, after a predetermined time (for example, 10 seconds) has elapsed since the sensor unit 1B was installed on the top surface 102 of the housing 100 and the door 101 was closed. In this embodiment, the background image is an image of the inside of the housing 100 when there is nothing inside.

[0062] Furthermore, the detection unit 27 can use various already known image processing techniques to detect whether there is a change in the two images, whether the image is different from the background image, etc.

[0063] When the detection unit 27 detects a change in the image, it acquires the time when the image change occurred (what time the package was delivered).

[0064] The functions of the detection device 3A are described below. The following processing is performed each time the image sensor 21 acquires an imaging signal. When the image sensor 21 acquires an imaging signal, the processing unit 2 acquires the imaging signal via the cable. The image processing unit 24 converts the imaging signal into an image, and the transmission unit 22 transmits the converted image to the terminal 35 via the wireless communication system N. As a result, the terminal 35 can display the image on the display unit 35a.

[0065] Furthermore, the detection unit 27 detects whether the current image has changed, for example, from the background image. If a change has occurred, the detection unit 27 obtains the time when the image changed, and the transmission unit 22 transmits information indicating that the image has changed and information about the time when the image changed to the terminal 35 via the wireless communication system N. As a result, the terminal 35 can display on the display unit 35a that there is a package inside the housing 100 and the time when the package was placed inside.

[0066] According to this embodiment, by simply installing the sensor unit 1B on the housing 100 of the delivery box, it is possible to check on a handheld terminal 35 whether or not a package has arrived in the delivery box, as well as the time when the package arrived in the delivery box.

[0067] In this embodiment, the detection unit 27 detects that there has been a change in the image and the time of that change, but the processing performed by the detection unit 27 is not limited to this. For example, since there is a possibility that several items may be deposited at the same time, the detection unit 27 may determine that a package has been placed inside the housing 100 if the image does not change for a certain period of time (for example, about 10 seconds). Also, for example, if there is an object inside the housing 100, the detection unit 27 may record the next time there is a change in the image (when an additional package is deposited) and the time of that change, and display these.

[0068] Furthermore, the detection unit 27 may detect the percentage of pixels that have changed out of the total number of pixels used to acquire the imaging signal when there is a change in the image. For example, if the effective number of pixels is 54 x 54 pixels and there is a change in the image within a 40 x 40 pixel range, the detection unit 27 will detect that the image has changed in approximately 75% of the total imaging range, meaning that a large package has been inserted. Also, if the effective number of pixels is 54 x 54 pixels and there is a change in the image within a 10 x 10 pixel range, the detection unit 27 will detect that the image has changed in approximately 20% of the total imaging range, meaning that a small package (such as a postcard) has been inserted. The detection unit 27 may, for example, determine that a small package is inserted when the change is approximately 30% or less of the total imaging range, a large package is inserted when the change is approximately 70% or less of the total imaging range, and a medium-sized package is inserted in between. The detection unit 27 may then transmit the size of the detected package to the terminal 35. Furthermore, the detection unit 27 may detect the shape of the package placed in the delivery box or the like based on the contour of the image when there is a change in the image, and transmit that shape to the terminal 35. These processes of the detection unit 27 can be carried out using known image processing techniques, etc.

[0069] This allows users to check on their handheld terminal 35 whether or not a package has arrived in the delivery box, as well as whether or not they should go and pick up the package immediately (for example, small packages are not urgent, but large packages should be picked up immediately considering the next delivery attempt, and packages with a three-dimensional shape should be picked up immediately considering the next delivery attempt).

[0070] <Third Embodiment> Figure 8 shows a schematic diagram of the sensor unit 1 according to the third embodiment. The sensor unit 1 according to the third embodiment is identical to the sensor unit 1 according to the first embodiment. The sensor unit 1 is, for example, a device that detects objects inside an exhibition booth 106.

[0071] The exhibition booth 106 is constructed by combining rod-shaped or plate-shaped members. Multiple sensor units 1, i.e., image sensors 21, are installed in the exhibition booth 106. It is desirable to install the sensor unit 1 near the ceiling of the exhibition booth 106. Furthermore, it is desirable to install the sensor unit 1 in about three locations facing the aisle within the exhibition booth 106, at equal intervals and facing the aisle.

[0072] The following describes the functions of the sensor unit 1. When the image sensor 21 acquires an imaging signal, the transmission unit 22 transmits the imaging signal to the terminal 35 via the wireless communication system N. The terminal 35 then converts the imaging signal into an image using an image processing unit (not shown) and displays the image on the display unit 35a (see Figure 1) of the terminal 35. This process is performed each time the image sensor 21 acquires an imaging signal. As a result, the user using the terminal 35 can check the image captured by the sensor unit 1 at any stage.

[0073] According to this embodiment, the terminal 35 can be used to appropriately determine the number of people (whether there are many or few people) inside the exhibition booth 106. Therefore, it eliminates the need for manual data entry and allows for remote monitoring of congestion and other conditions. Considering the future society of population decline and labor shortages, this is convenient as it eliminates the need for human verification. In particular, considering the future aging society, it can also be used for monitoring, crime prevention, and disaster prevention.

[0074] Furthermore, according to this embodiment, the number of pixels used to acquire the imaging signal is reduced in order to be powered by the battery 23 (for example, the effective number of pixels of the image sensor 21 is 54 x 54 pixels), and detailed images of people are not captured. Therefore, the location and number of people (crowding) can be determined without infringing on privacy.

[0075] In this embodiment, the sensor unit 1 continuously acquires imaging signals, but the period during which the sensor unit 1 acquires imaging signals is not limited to this, and the sensor unit 1 may acquire imaging signals only for any period of time. For example, a human presence sensor such as a pyroelectric infrared sensor may be installed at any position in the exhibition booth 106, and imaging may be started by the image sensor 21 when a person is detected by the human presence sensor. Alternatively, imaging by the image sensor 21 may be stopped after a predetermined period (e.g., 10 minutes) has elapsed after a person has been detected by the human presence sensor.

[0076] <Fourth Embodiment> The detection device 3B according to the fourth embodiment will be described below. Parts identical to those in the first to third embodiments and their modified forms are denoted by the same reference numerals and their descriptions are omitted.

[0077] Figure 9 is a schematic diagram of the detection device 3B, which includes a sensor unit 1C. The detection device 3B mainly consists of a plurality of sensor units 1C installed in the exhibition booth 106 and a processing unit 2B connected to the sensor units 1C wirelessly or by wire (wireless in this embodiment).

[0078] Figure 10 is a block diagram showing a schematic electrical configuration of a modified detection device 3B. The sensor unit 1C mainly comprises an image sensor 21, a battery 23, and a wireless communication unit 25. The processing unit 2B mainly comprises an image processing unit 24, a transmission unit 22, a detection unit 27, and a wireless communication unit 25.

[0079] The wireless communication unit 25 includes an antenna and other components, and is a functional unit that communicates via short-range wireless communication protocols such as Wi-Fi (registered trademark), Bluetooth (registered trademark), and infrared, and transmits and receives imaging signals and other data.

[0080] The functions of the detection device 3B are described below. When the image sensor 21 acquires an imaging signal, the processing unit 2 acquires the imaging signal via the wireless communication unit 25. The image processing unit 24 converts the imaging signal into an image, and the transmission unit 22 transmits the converted image to the terminal 35 via the wireless communication system N. As a result, the terminal 35 can display the image on the display unit 35a.

[0081] This process is performed each time the image sensor 21 acquires an imaging signal. As a result, the user using the terminal 35 can view the image captured by the sensor unit 1 in real time.

[0082] According to this embodiment, the terminal 35 can be used to appropriately determine the number of people inside the exhibition booth 106 (whether there are many or few people). Furthermore, if multiple sensor units 1B are installed in separate exhibition booths 106, the congestion level of each exhibition booth 106 can be determined.

[0083] <Modified form of the fourth embodiment> The following describes a modified detection device 3C. Parts identical to those in the first to fourth embodiments are denoted by the same reference numerals and their descriptions are omitted.

[0084] Figure 10 is a block diagram showing a schematic electrical configuration of a modified detection device 3C. The detection device 3C mainly comprises a sensor unit 1C and a processing unit 2C. The processing unit 2C mainly comprises an image processing unit 24, a transmission unit 22, a wireless communication unit 25, and a detection unit 27A.

[0085] The detection unit 27A is a functional unit that detects whether or not there is a change in the image generated by the image processing unit 24 based on the imaging signal acquired by the sensor unit 1C, i.e., the image sensor 21. For example, the detection unit 27A detects whether or not there is a change in the image acquired by the image sensor 21 by detecting whether or not the image acquired by the image sensor 21 at any given time (corresponding to the first time in this invention) is different from the background image. Here, the background image is an image generated based on the imaging signal acquired at a time earlier than any given time (corresponding to the second time in this invention) (corresponding to the second time in this invention). In this embodiment, the background image is an image of the exhibition booth 106 when there are no visitors (for example, when there are no people other than in a predetermined position (reception, etc.)).

[0086] Furthermore, if a person (object) is detected by comparing it with the background image, the detection unit 27A detects changes in the two consecutive images, i.e., the movement of the object or whether or not the object is included in the image.

[0087] Furthermore, the detection unit 27A can detect the movement of an object and whether or not the object is included in the image using various already known image processing techniques.

[0088] The detection unit 27A records the movement status of each detected object (for example, whether or not the object is moving, the direction of movement, etc.). The detection unit 27A also obtains the number of detected objects.

[0089] The following describes the functions of the detection device 3C. The following processing is performed each time the image sensor 21 acquires an imaging signal. When the image sensor 21 acquires an imaging signal, the processing unit 2 acquires this imaging signal. The image processing unit 24 converts the imaging signal into an image, and the transmission unit 22 transmits the converted image to the terminal 35 via the wireless communication system N. As a result, the terminal 35 can display the image on the display unit 35a.

[0090] Furthermore, the detection unit 27A detects objects by comparing the current image with the background image. The detection unit 27A also detects the movement of the detected object. The transmission unit 22 then transmits information about the object's movement (for example, whether the object is moving or remaining in place) to the terminal 35 via the wireless communication system N. As a result, the terminal 35 can display the image acquired by the image sensor 21 and the object's movement status on the display unit 35a.

[0091] According to this embodiment, a user using the terminal 35 can check images and congestion (number of detected objects) within the exhibition booth 106 at any stage. Furthermore, if there is no movement of objects for a certain period of time, the detection unit 27A can issue an alert, making it usable for monitoring.

[0092] Furthermore, if there is a change in the image, the detection unit 27A may detect the percentage of the number of pixels that have changed out of the total number of pixels used to acquire the imaging signal. For example, if the effective number of pixels is 54 x 54 pixels and there is a change in the image in the range of 40 x 40 pixels, the detection unit 27A will detect that the image has changed in approximately 75% of the total imaging range, meaning that there are many people inside the exhibition booth 106. Also, if the effective number of pixels is 54 x 54 pixels and there is a change in the image in the range of 10 x 10 pixels, the detection unit 27 will detect that the image has changed in approximately 20% of the total imaging range, meaning that there are a few people inside the exhibition booth 106. The detection unit 27A can also determine that there are few people inside the exhibition booth 106 when the change is approximately 30% or less of the total imaging range, there are many people inside the exhibition booth 106 when the change is approximately 70% or less of the total imaging range, and moderate congestion in between. The detection unit 27A may then transmit the detected level of congestion to the terminal 35. The processing of these detection units 27A can be carried out using known image processing techniques.

[0093] While embodiments of this invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and design modifications and the like are also included within the scope of the gist of this invention. For example, the above embodiments are described in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace some of the configurations of an embodiment with those of another embodiment, and it is also possible to add, delete, or replace other configurations in an embodiment.

[0094] Furthermore, in this invention, "approximately" refers not only to cases where the two are strictly identical, but also to cases where there are errors or modifications that do not result in a loss of identity. Also, in this invention, "neighborhood" means a certain range (which can be arbitrarily defined) near the reference position. [Explanation of Symbols]

[0095] 1, 1A, 1B, 1C: Sensor Unit 2, 2A, 2B, 2C: Processing Units 3, 3A, 3B, 3C: Detection device 21: Image sensor 22: Transmitter 23: Battery 24: Image Processing Unit 25: Wireless Communication Department 27, 27A: Detection unit 31, 32: Circuit board 35: Terminal 35a: Display section 51: CPU 51a: Control Unit 52: RAM 53: ROM 54: Communication Interface 100: Cabinet 101: Door 102: Top surface 103: Bottom 104: Side view 106: Exhibition Booth

Claims

1. A sensor unit that transmits data to a terminal via a mobile communication system, An image sensor is provided inside an arbitrary region and acquires imaging signals from within the region at regular intervals. A transmitting unit that transmits the imaging signal to the terminal, The image sensor and the battery that powers the transmission unit, Equipped with, The number of pixels used to acquire the aforementioned imaging signal is 54 x 54 pixels or less. A sensor unit characterized by the following features.

2. The system includes an image processing unit that generates an image from the aforementioned imaging signal, The transmission unit transmits the image generated by the image processing unit to the terminal. The sensor unit according to feature 1.

3. The aforementioned region is a space enclosed by a housing with doors formed on its sides. The image sensor is located inside the housing and is provided on the top or side surface of the housing. The area in which the image sensor acquires the imaging signal includes the bottom surface of the housing. The sensor unit according to claim 1 or 2, characterized in that it is as described above.

4. The aforementioned area is an exhibition booth installed by combining rod-shaped members or plate-shaped members. Multiple image sensors are provided in the aforementioned exhibition booth. The sensor unit according to claim 1 or 2, characterized in that it is as described above.

5. A sensor unit that transmits at least an image to a terminal via a mobile communication system, A sensor unit comprising: an image sensor located inside an arbitrary region and acquiring imaging signals from within the region at regular intervals; and a battery that drives the image sensor. The sensor unit is connected to a processing unit that acquires the imaging signal, Equipped with, The processing unit comprises an image processing unit that generates an image from the imaging signal and a transmission unit that transmits data to the terminal via a mobile communication system. The number of pixels used to acquire the aforementioned imaging signal is 54 x 54 pixels or less. The transmission unit transmits the image generated by the image processing unit to the terminal. A detection device characterized by the following features.

6. The processing unit includes a detection unit that detects whether or not there is a change in the image generated by the image processing unit. The transmitting unit transmits the detection result of the detection unit to the terminal. The detection device according to feature 5.

7. The detection unit detects whether or not there is a change in the two images generated by the image processing unit based on the two image signals acquired consecutively by the image sensor. The detection device according to feature 6.

8. The detection unit detects whether the image at the first time point has changed compared to the background image, which is the image at the second time point prior to the first time point. The detection device according to claim 6 or 7, characterized by the above.

9. The detection unit detects, when there is a change in the image, the ratio of the number of pixels that have changed out of the total number of pixels used to acquire the imaging signal. The detection device according to any one of claims 6 to 8.

10. The aforementioned region is a space enclosed by a housing with doors formed on its sides. The image sensor is located inside the housing and is provided on the top or side surface of the housing. The area in which the image sensor acquires the imaging signal includes the bottom surface of the housing. The detection device according to any one of claims 5 to 9.

11. The aforementioned area is an exhibition booth installed by combining rod-shaped members or plate-shaped members. Multiple image sensors are provided in the aforementioned exhibition booth. The detection device according to any one of claims 5 to 9.

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