Luminous device recognition system and luminous device

Abstract

The present invention provides a light-emitting device recognition system and a light-emitting device. The light-emitting device has a light source that flashes according to the recognition information inherent in the self-light-emitting device; a camera device that captures the light of the light source of the light-emitting device; a recognition device that recognizes the light-emitting device according to the light of the light source of the light-emitting device that appears in the captured image of the camera device; and an electromagnetic wave transmitting element that emits electromagnetic waves from the camera device or the periphery of the camera device, the light-emitting device also having an electromagnetic wave receiving element that receives the electromagnetic waves from the electromagnetic wave transmitting element, and the light-emitting device changes the light intensity of the light source according to the intensity of the electromagnetic waves received by the electromagnetic wave receiving element.

Description

Technical Field

[0001] The present disclosure relates to a light emitting device recognition system and a light emitting device. Background Art

[0002] A system is known, which includes: a light emitting device (also called a tag) having a light source attached to a moving object such as a person or an object, the light source flashing based on inherent identification information; and a camera that is a device for photographing the light of the light source of the light emitting device, the system recognizes the light emitting device based on the light of the light source of the light emitting device appearing in the photographed image of the camera, and determines the position of the light emitting device. Hereinafter, the system is referred to as a light emitting device recognition system.

[0003] Japanese Patent Gazette No. 2016-71663 discloses a system including a tag and a camera for reading information on the tag, wherein the camera emits infrared light to the tag, the tag receives the infrared light and reflects the infrared light by switching on / off a liquid crystal to include the information on the tag, and the camera receives the reflected infrared light to interpret the information on the tag.

[0004] Japanese Patent Gazette No. 2011-192236 discloses a system including a tag reader having a camera device and a tag that sends a tag identification value by emitting light, wherein the tag reader determines the light-emitting state of the tag based on image information of a specified portion in a frame read from the camera device, and identifies the tag identification value based on the determination result.

[0005] Japanese Patent Publication No. 2003-329762 discloses an object positioning system, which includes: a light-emitting unit that moves together with the object and emits infrared rays; a photographing unit that photographs an infrared image of a specified photographing area including the object; and a position determination unit that determines the position of the light-emitting unit based on the infrared image.

[0006] Japanese Patent Application Laid-Open No. 2010-217093 discloses a system including: a tag that transmits ID information of its own tag through an electric wave signal and transmits a light flashing signal simultaneously with the electric wave signal or with a certain time difference; and a tag reader device that receives the electric wave signal from the tag and photographs the tag. The tag reader device calculates the position of the tag based on the position of the light flashing signal in the photographed image, and makes the ID information of the received electric wave signal correspond to the position of the tag based on the relationship between the timing of the light flashing signal and the received electric wave signal.

[0007] In a light emitting device recognition system, when a light emitting device moves away from a camera, the light of the light emitting device becomes smaller or the brightness becomes lower in the camera's captured image, making it difficult to recognize the light emitting device. Summary of the invention

[0008] An object of the present invention is to make it easier to identify a light emitting device compared to a case where the light emitting device emits light regardless of the distance between the light emitting device and an imaging device.

[0009] According to a first embodiment of the present invention, there is provided a light emitting device identification system, which comprises: a light emitting device having a light source that flashes according to identification information inherent in the light emitting device; a camera device that captures light from the light source of the light emitting device; an identification device that identifies the light emitting device based on the light from the light source of the light emitting device appearing in a camera image captured by the camera device; and an electromagnetic wave transmitting element that emits electromagnetic waves from the camera device or the periphery of the camera device, the light emitting device further having an electromagnetic wave receiving element that receives the electromagnetic waves from the electromagnetic wave transmitting element, the light emitting device changes the light emission intensity of the light source according to the intensity of the electromagnetic waves received by the electromagnetic wave receiving element.

[0010] According to the second aspect of the present invention, the greater the intensity of the electromagnetic wave received by the electromagnetic wave receiving element, the smaller the light emission intensity of the light source is caused by the light emitting device.

[0011] According to a third aspect of the present disclosure, the light of the light emitting device is a first infrared ray, and the electromagnetic wave of the electromagnetic wave transmitting element is a second infrared ray having a central wavelength different from that of the first infrared ray.

[0012] According to a fourth aspect of the present disclosure, the light of the light emitting device is infrared light, and the electromagnetic wave of the electromagnetic wave transmitting element is a radio wave.

[0013] According to the fifth scheme of the present disclosure, the light-emitting device recognition system includes multiple combinations of the camera device and the electromagnetic wave sending element, the electromagnetic waves emitted by the multiple electromagnetic wave sending elements each have a different central wavelength, and the light-emitting device changes the light intensity of the light source according to the electromagnetic wave with the maximum intensity among the multiple electromagnetic waves received by the electromagnetic wave receiving element.

[0014] According to the sixth scheme of the present disclosure, the light-emitting device recognition system includes multiple combinations of the camera device and the electromagnetic wave sending element, the electromagnetic waves emitted by the multiple electromagnetic wave sending elements have different central wavelengths, and the light-emitting device changes the light intensity of the light source according to the electromagnetic wave with the second largest intensity among the multiple electromagnetic waves received by the electromagnetic wave receiving element.

[0015] According to the seventh scheme of the present disclosure, a light-emitting device is provided, which includes: a light source that flashes according to identification information inherent in the self-luminous device; and an electromagnetic wave receiving element that receives electromagnetic waves emitted from a camera device that captures light from the light source or from the periphery of the camera device, wherein the light-emitting device changes the light emission intensity of the light source according to the intensity of the electromagnetic waves received by the electromagnetic wave receiving element.

[0016] (Effect)

[0017] According to the first or seventh aspect, the light emitting device can be easily identified compared to the case where the light emitting device is caused to emit light regardless of the distance between the light emitting device and the imaging device.

[0018] According to the second aspect, it is possible to prevent the intensity of light emitted by the light emitting device from being excessive or too low.

[0019] According to the third or fourth aspect, the light of the light source of the light emitting device and the electromagnetic wave of the electromagnetic wave transmitting element are invisible, and it is possible to suppress their mutual influence.

[0020] According to the fifth aspect, compared with a case where the light emission intensity of the light source of the light emitting device is not changed according to the electromagnetic wave of the maximum intensity, the power consumption of the light source of the light emitting device can be suppressed.

[0021] According to the sixth aspect, the possibility of identifying the light-emitting device by two or more imaging devices increases. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of a tag identification system according to one embodiment of the present disclosure.

[0023] Figure 2 It is a diagram for explaining a tag recognition system.

[0024] Figure 3 It is a block diagram of the tag recognition system.

[0025] Figure 4 This is a diagram showing an example of the central wavelength of light emitted by the identification light emitting element and the distance light emitting element.

[0026] Figure 5A This is a diagram showing an example of a lighting pattern of 0, 1 of a light source representing a tag.

[0027] Figure 5B This is a diagram showing another example of the lighting pattern of 0, 1 of the light source representing the tag.

[0028] Figure 6 This is a diagram showing an example of a blinking pattern of a light source of a tag.

[0029] Figure 7 : is a flowchart showing the control flow of the light source of the tag.

[0030] Figure 8 : is a diagram showing an example of the relationship between the average received light intensity and the light emission intensity of a tag.

[0031] Fig. 9 It is a diagram for explaining the light emission intensity of a tag corresponding to the distance between a camera and the tag.

[0032] Fig.10 This is a schematic diagram of a tag recognition system with multiple readers.

[0033] Fig.11 This is a diagram showing an example of the central wavelength of light emitted by the identification light emitting element and the plurality of distance light emitting elements.

[0034] Fig.12 is a flow chart showing control of a light source of a tag in a tag recognition system having multiple readers.

[0035] Fig.13 is a flow chart showing other control of a light source of a tag in a tag recognition system having multiple readers.

[0036] Fig.14 is a block diagram of a tag identification system according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0037] Hereinafter, each embodiment according to the present disclosure will be described in detail with reference to the accompanying drawings. The structure described below is an example for explanation and can be appropriately changed according to the specifications of the system, device, and component. In addition, in the case where the following includes multiple embodiments or variations, it is envisaged from the beginning that these feature parts will be used in appropriate combination. In all the drawings, the same symbols are given to the same elements, and repeated descriptions are omitted.

[0038] Figure 1 : is a schematic structural diagram of a tag identification system 10 according to an embodiment of the present disclosure. The tag identification system 10 includes: tags 14a, 14b, 14c as light-emitting devices, which have light sources 30 attached to moving objects such as people, animals, and objects and flash according to inherent identification information; and cameras 16 as imaging devices, which capture the light of the light sources 30 of the tags 14a, 14b, 14c. The tag identification system 10 recognizes the tags 14a, 14b, 14c, respectively, based on the light of the light sources 30 of the tags 14a, 14b, 14c that appear in the captured images of the camera 16, and determines the positions of the tags 14a, 14b, 14c. In addition, the number of tags and the number of cameras can be appropriately changed.

[0039] exist Figure 1 In the figure, as one usage of the tag recognition system 10, the following method is shown: a tag is attached to the chest of each attendee in the exhibition hall, the light source 30 of the tag is flashed according to the identification information inherent to the attendee, and each tag attached to the chest of the attendee is identified based on the light of the light source 30 of the tag 14a, 14b, 14c that appears in the camera image of the camera 16, and the position of each attendee is determined. The position of the attendee is determined by the position of the light of the tag in the camera image, the position of the camera that captures the light of the tag when there are multiple cameras, and the like. According to this usage method, it is possible to collect information such as which shed in the exhibition hall each attendee visited and how long he stayed, and for example, it is possible to obtain an information source for understanding what each attendee is interested in.

[0040] As another usage, the tag recognition system 10 can also be used for example for the manufacturing management of articles. Tags are added to the intermediates that are processed in sequence in each process and transferred to the next process, and the light source of the tag is flashed according to the inherent identification information of the intermediates. The light of the light source of the tag that appears in the camera image is used to identify each intermediate and determine the position of the intermediate. According to this usage, for example, it is possible to determine which process each intermediate is currently in. In addition, the above-mentioned usages are only examples, and the usage of the tag recognition system 10 is not limited.

[0041] The tag recognition system 10 of this embodiment includes a distance light emitting element 18 that emits infrared light from a camera 16 or the periphery of the camera 16. The distance light emitting element is not limited to an element that emits infrared light, but can be an element that emits electromagnetic waves including visible light. The reader 12 is composed of the camera 16 and the distance light emitting element 18. Figure 2 As shown, the tag 14 includes a distance light receiving element 32 that receives infrared light from the distance light emitting element 18. The distance light receiving element 32 is not limited to an element that receives infrared light, but can be an element that receives electromagnetic waves of a frequency band corresponding to the electromagnetic waves sent by the distance light emitting element 18, which sends electromagnetic waves including visible light and the like.

[0042] The tag 14 changes the light intensity of the light source 30 according to the intensity of the infrared light received by the distance light receiving element 32. When the intensity of the infrared light received by the distance light receiving element 32 of the tag 14 is weak, it means that the distance between the tag 14 and the distance light emitting element 18 is far. In other words, it means that the distance between the tag 14 and the camera 16 is far. On the other hand, when the intensity of the infrared light received by the distance light receiving element 32 of the tag 14 is strong, it means that the distance between the tag 14 and the distance light emitting element 18 is short. In other words, it means that the distance between the tag 14 and the camera 16 is short.

[0043] When the intensity of infrared light received by the light receiving element 32 at the distance of the tag 14 is weak, the light intensity of the light source 30 of the tag 14 can be increased to increase the light or brightness of the tag 14 in the image captured by the camera 16. That is, the intensity of the light emitted by the tag 14 is prevented from being too low, and the tag 14 can be easily identified in the captured image.

[0044] On the other hand, when the intensity of infrared light received by the light receiving element 32 of the tag 14 is strong, the power consumption of the light source 30 can be suppressed by reducing the light intensity of the light source 30 of the tag 14. In this way, even if the light intensity of the tag is reduced, since the distance between the tag 14 and the camera 16 is close, the light of the light source 30 of the tag 14 can be recognized from the image captured by the camera 16, and the excessive intensity of the light emitted by the tag 14 can be prevented.

[0045] Figure 3 1 is a block diagram of a tag recognition system 10 according to the present embodiment. The tag recognition system 10 includes a tag 14 as a light emitting device and a reader 12. The light source 30 of the tag 14 is an infrared light emitting element that emits infrared rays. The light emitting element is a light emitting element that emits light in a flashing pattern for identifying the tag, and is an identification light emitting element for identifying the tag by imaging and analyzing it with a camera 16. The camera 16 of the reader 12 is an infrared camera that captures the infrared rays of the light source 30 of the tag 14.

[0046] The tag 14 includes: a light source 30 that flashes with infrared light based on its own inherent identification information; a distance light receiving element 32 that receives infrared light from the distance light emitting element 18 of the reader 12; a processor 34 that is electrically connected to the light source 30 and the distance light receiving element 32; a memory 36 that stores identification information 45 and the like read from the processor 34; and a battery (not shown) that supplies power to each part of the tag 14. The processor 34 is used as a light intensity acquisition unit 42, a light intensity control unit 40, and a flashing mode control unit 38. The light intensity acquisition unit 42 acquires the light intensity of infrared light from the distance light emitting element 18 of the reader 12 received by the distance light receiving element 32; the light intensity control unit 40 controls the light intensity of the light source 30 based on the light intensity acquired by the light intensity acquisition unit 42; and the flashing mode control unit 38 controls the flashing of the light source 30 in a flashing mode based on the identification information 45.

[0047] The reader 12 includes: a camera 16 as a camera device, which captures the flashing of a light source 30 that emits infrared rays from the tag 14; a distance light-emitting element 18, which lights up infrared rays from the camera 16 or the periphery of the camera 16; and an identification device 20, which identifies the tag 14 based on the light emitted by the light source 30 of the tag 14 that appears in the camera image of the camera 16, i.e., infrared rays.

[0048] The recognition device 20 is electrically connected to the camera 16 and the distance light emitting element 18. The recognition device 20 includes a processor 22 and a memory 24. The processor 22 obtains the camera images sent sequentially from the camera 16 and stores them in the memory 24. The camera images taken by the camera 16 in the past certain period are temporarily stored in the memory 24. The camera images can be obtained in the form of dynamic images, and are processed in units of static images, i.e., frame images, which are frames cut out in time sequence. The processor 22 functions as a tag recognition unit 26, which reads the camera images from the memory 24, recognizes the tag 14 by interpreting the flashing of the light source 30 of the tag 14 appearing in the camera images, and determines the position of the tag 14 according to the position of the light in the camera images. In addition, the processor 22 functions as a light emission wavelength control unit 28 that controls the wavelength of infrared light emitted from the distance light emitting element 18. In addition, in the present embodiment, the light emission wavelength control unit 28 is included in the recognition device 20, but it can also be included in a device different from the recognition device 20 and realized by a processor in a different device.

[0049] Furthermore, the recognition device 20 may not be included in the reader 12. When there are a plurality of readers 12, a common recognition device 20 may be provided for the plurality of readers 12. When the tag 14 is photographed by a plurality of cameras 16, the position of the tag 14 may be determined by the tag recognition unit 26 of the recognition device 20 based on the position of each camera 16 and the image captured by each camera 16.

[0050] Figure 4 This is a diagram showing an example of the center wavelength λ1 of light (also referred to as first infrared light) emitted from the light source 30 as the identification light emitting element of the tag 14 and the center wavelength λ2 of light (also referred to as second infrared light) emitted from the distance light emitting element 18 of the reader 12. Here, the center wavelength refers to a wavelength or a wavelength region where the light emission intensity of each light is the strongest.

[0051] like Figure 4 As shown, the center wavelengths λ1 and λ2 of the light emitted from the light source 30 as the identification light emitting element of the tag 14 and the distance light emitting element 18 of the reader 12 are both in the infrared region. Therefore, each light can be made invisible or almost invisible, and each light is less susceptible to noise from lighting, etc. In addition, since the center wavelength λ1 of the infrared light of the light source 30 and the center wavelength λ2 of the infrared light of the distance light emitting element 18 are offset by a predetermined wavelength width, the infrared light of the light source 30 and the infrared light of the distance light emitting element 18 can be suppressed from influencing each other.

[0052] Next, the blinking pattern of the light source 30 of the tag 14 will be described. Figure 5A , Figure 5B 1 is a diagram showing an example of a lighting pattern of 0, 1 of the light source 30 of the tag 14. Figure 6 1 is a diagram showing an example of a flashing pattern of the light source 30 of the tag 14. Figure 6 As shown, the blinking pattern includes a start pattern and an identification pattern directly or indirectly indicating unique identification information of the tag 14. The identification pattern is formed by combining a plurality of lighting patterns indicating 0 or 1, and the start pattern is formed by a pattern other than the lighting pattern indicating 0 or 1.

[0053] like Figure 5A and Figure 5B As shown, the lighting pattern representing 0 or 1 is represented by a plurality of frame times. The frame time is the time interval between frame images captured and obtained by the camera 16 of the reader 12. For example, when the camera 16 obtains 30 frame images in 1 second, the frame time is approximately 33 milliseconds. Figure 5A , Figure 6 In FIG. 1 , an example of using 3 frame times (3 times the frame time) to represent a lighting pattern of 0 or 1 is shown. Figure 5B , an example of using 6 frame times (6 times the frame time) to represent a lighting pattern of 0 or 1 is shown.

[0054] In this way, by using a plurality of frame times to represent a lighting pattern representing 0 or 1, when the light of the tag 14 is photographed by the camera 16, even if noise is mixed in one or more frame images in the lighting pattern representing 0 or 1, and the lighting or extinguishing of the light of the tag 14 cannot be identified in the frame image, it is possible to identify 0 or 1 based on other frame images in the lighting pattern. That is, the lighting pattern representing 0 or 1 is made to have temporal redundancy, so that the noise durability when identifying 0 or 1 can be improved. In addition, in the present embodiment, a plurality of frame times are used to represent the lighting pattern representing 0 or 1 (with redundancy), but it is also possible to use a single frame time to represent 0 or 1 (for example, 0 is represented by extinguishing and 1 is represented by lighting).

[0055] The flashing pattern control unit 38 of the tag 14 controls the light source 30 so that the light source 30 repeatedly transmits the flashing pattern at predetermined time intervals (see Figure 6 ). The tag recognition unit 26 of the reader 12 recognizes the start of the flashing pattern by the appearance of a lighting pattern (starting pattern) other than 0 or 1 in the camera image, and recognizes the recognition pattern following the start pattern in the flashing pattern. Then, the tag recognition unit 26 obtains the identification information 45 of the tag 14 by interpreting (also called decoding) the recognition pattern. In addition, the flashing pattern may be a method in which an end pattern follows the recognition pattern, a method in which a pattern for error detection and correction is added, a method in which the start pattern is represented by a predetermined pattern of 0, 1, etc. The method of the flashing pattern is not limited.

[0056] Next, control of the light source 30 by the processor 34 of the tag 14 will be described. Figure 7 1 is a flow chart showing the control flow of the light source 30 of the tag 14. First, Figure 7 In S100, the processor 34 functions as the light intensity acquisition unit 42, and acquires the light intensity of infrared light received by the distance light receiving element 32 of the tag 14 within a predetermined time. Then, in S102, the light intensity acquisition unit 42 acquires the average of the light intensities acquired in S100 as the average light intensity.

[0057] Next, in S104 , the processor 34 functions as the emission intensity control unit 40 to set the emission intensity of the light source 30 based on the average received light intensity acquired in S102 . Figure 8 3 is a diagram showing an example of the relationship between the average light receiving intensity and the light emission intensity used when setting the light emission intensity of the light source 30. This relationship can be expressed by, for example, an arithmetic expression, or can be stored as a table in the memory 36. The light emission intensity control unit 40 is as follows. Figure 8 As shown, the luminous intensity of the light source 30 is set in such a manner that the smaller (weaker) the average received light intensity is, the larger (stronger) the luminous intensity of the light source 30 is. In other words, the luminous intensity control unit 40 sets the luminous intensity of the light source 30 in such a manner that the luminous intensity of the light source 30 is smaller (weaker) as the average received light intensity is larger (stronger).

[0058] Next, in S106, the processor 34 functions as the flashing mode control unit 38, reads the identification information 45 from the memory 36, and controls the light source 30 so that the light source 30 is in accordance with the flashing mode control unit 38. Figure 6 The blinking pattern shown blinks. The blinking pattern control unit 38 controls the light source 30 so that the blinking pattern is repeatedly transmitted at predetermined time intervals.

[0059] According to the tag recognition system 10 (light emitting device recognition system) of the present embodiment described above, Fig. 9 As shown in FIG. 1 , the intensity of light received by the distance light emitting element 18 of the reader 12 of the tag 14c located far from the reader 12 becomes smaller, so the light intensity of the light source of the tag 14c is set to be larger. Therefore, even if the tag 14c is located far from the reader 12, the light of the light source of the tag 14c appears larger and brighter in the image captured by the camera 16 of the reader 12, and the tag 14c can be easily identified from the captured image.

[0060] In addition, the intensity of light received by the distance light emitting element 18 of the tag 14a, 14b located at a position relatively close to the reader 12 becomes larger, so the light emission intensity of the light source of the tag 14a, 14b is set relatively small. Therefore, the power consumption of the light source of the tag is suppressed, and the energy consumption of the battery included in the tag is suppressed.

[0061] In addition, when the tag 14a located close to the reader 12 emits light with increased light intensity, the following problem may occur. Fig. 9 As shown by the dotted arrow in FIG. 1 , the light of the tag 14a is reflected by the wall 50 and the like and enters the camera 16, making it difficult to identify the light of the tag 14a from the camera image. Fig. 9 In the camera image, the position of the tag is misidentified as if the tag exists in a part of the wall 50, as shown in the misidentified tag 15. However, according to the tag recognition system 10 of this embodiment, since the light emission intensity of the tag 14a located close to the reader 12 is set to be small, the occurrence of this situation can be suppressed.

[0062] Next, a tag recognition system 10 having a plurality of readers 12 will be described. Fig.10 As shown, when there are multiple readers 12a, 12b, and 12c, the distance light receiving element 32 of the tag 14 receives light (infrared rays) from the distance light emitting elements 18a, 18b, and 18c of the readers 12a, 12b, and 12c, respectively. Fig.10 In FIG. 1 , as an example, a mode in which the distance light receiving element 32 receives light from three distance light emitting elements 18 a , 18 b , and 18 c is shown.

[0063] Fig.11 1 is a diagram showing an example of the central wavelength λ1 of the light emitted by the light source 30 of the tag 14 and the central wavelengths λ2a, λ2b, and λ2c of the light emitted by the three distance light emitting elements 18a, 18b, and 18c of the three readers, respectively. Fig.11 As shown, the center wavelengths λ1, λ2a, λ2b, λ2c of the light emitted by the light source 30 and the distance light emitting elements 18a, 18b, 18c, respectively, are in the infrared region. Therefore, each light can be made invisible or almost invisible, and each light is less susceptible to noise from lighting, etc. In addition, the center wavelength λ1 of the infrared light of the light source 30 and the center wavelengths λ2a, λ2b, λ2c of the infrared light of the distance light emitting elements 18a, 18b, 18c are respectively set to be separated from the adjacent center wavelengths by at least a specified wavelength width. Therefore, it is possible to suppress the infrared light of the light source 30 and the infrared light of the distance light emitting elements 18a, 18b, 18c from influencing each other. In addition, the center wavelengths of the distance light emitting elements 18a, 18b, 18c are controlled by the light emission wavelength control unit 28 of the reader (refer to Figure 3 The infrared light emission intensities of the distance light emitting elements 18a, 18b, and 18c are set to be the same or substantially the same.

[0064] like Fig.10As shown, regarding the light intensity of infrared light received by the distance light receiving element 32 of the tag 14, the infrared light of the distance light emitting element 18a closest to the tag 14 is the strongest, the infrared light of the distance light emitting element 18c farthest from the tag 14 is the weakest, and the infrared light of the distance light emitting element 18b farther from the tag 14 than the distance light emitting element 18a and closer than the distance light emitting element 18c is of intermediate intensity. There are various options for setting the light intensity of infrared light of the light source 30 of the tag 14 based on which distance light emitting element 18a, 18b, 18c is used as a reference. Two embodiments are shown below regarding the setting of the light intensity of the light source 30 of the tag 14 when the tag 14 receives infrared light from multiple readers.

[0065] Fig.12 FIG. 1 is a flowchart showing the control of the light source 30 of the tag 14 in the tag recognition system having multiple readers. Fig.12 In S200, the processor 34 of the tag 14 (refer to Figure 3 ) functions as a light receiving intensity acquisition unit 42, and acquires the light receiving intensity of each infrared ray with different central wavelengths received by the distance light receiving element 32 of the tag 14 from the plurality of distance light emitting elements within a predetermined time. The light receiving intensity acquisition unit 42 acquires the light receiving intensity of each infrared ray with different central wavelengths of the plurality of distance light emitting elements 18a, 18b, 18c by performing wavelength decomposition on the light received by the distance light receiving element 32. Then, in S202, the light receiving intensity acquisition unit 42 acquires the average of the light receiving intensities acquired in S200 as each average light receiving intensity.

[0066] Next, in S204, the processor 34 functions as the light intensity control unit 40 to set the light intensity of the light source 30 according to the strongest average light intensity among the average light intensity obtained in S202. That is, the light intensity of the light source 30 is set based on the average light intensity of the infrared light received from the reader closest to the tag 14. Fig.10 In the embodiment, the light emission intensity of the light source 30 is set according to the intensity of the infrared light received from the distance light emitting element 18a of the reader 12a.

[0067] Next, in S206, the processor 34 functions as the flashing pattern control unit 38, reads the identification information 45 from the memory 36, and performs the flashing pattern control according to the following steps: Figure 6 The blinking mode shown controls the light source 30 to blink.

[0068] According to the control of the light source 30 of the tag 14 described above, the light emission intensity of the tag is set relatively low based on the distance light emitting element 18a of the reader 12a closest to the tag 14, so that the power consumption of the light source 30 of the tag 14 can be suppressed. In this way, even if the light emission intensity of the tag 14 is reduced, the distance between the tag 14 and the camera of the reader 12a is short, so that the light of the light source 30 of the tag 14 can be recognized from the camera image. The control described above can be called an energy saving mode.

[0069] Fig.13 1 is a flowchart showing other control of the light source 30 of the tag 14 in the tag recognition system having multiple readers. Fig.12 The process and Fig.13 The difference in the process is that instead of Fig.12 In S204 of the process of "setting the luminous intensity based on the strongest average light intensity", Fig.13 In the process of , in S304, it is set to "set the luminous intensity based on the second strongest average light intensity". That is, based on the second closest reader to the tag 14 (in Fig.10 The average light intensity of infrared light received by the reader 12b (distance light emitting element 18b) is set to set the light intensity of the light source 30. Fig.10 The camera image of the reader 12a in the middle and the camera image of the second closest reader (in Fig.10 In the image captured by the camera of the reader 12b), the light of the light source 30 of the tag 14 is clearly presented. Based on these two captured images, the position of the tag can be determined with high accuracy. This control can be called a high-precision mode.

[0070] Furthermore, when the distance light receiving element 32 of the tag 14 receives infrared light from the distance light emitting elements of a plurality of readers, the light emission intensity of the light source 30 may be set according to the intensity of the infrared light received from the nth (n is an integer greater than or equal to 3) nearest reader (distance light emitting element). In this case, the light of the light source 30 of the tag 14 is clearly presented in n camera images, and the position of the tag 14 can be determined more accurately based on these camera images.

[0071] Next, the tag recognition system of other embodiments is described. In the tag recognition system of the embodiment described above, the reader with the distance light-emitting element emits infrared rays to be received by the tag, but it is also possible to send radio waves of a specified frequency band as a type of electromagnetic wave instead of infrared rays. In addition, the tag can also receive radio waves from the reader and change the light intensity of the light source 30 according to the intensity of the received radio waves. Fig.14 is a block diagram of a tag identification system in this other embodiment. Fig.14 The block diagram and Figure 3 The difference between the block diagrams is that Fig.14 middle, Figure 3 The distance light emitting element 18 is replaced by the distance radio wave transmitting element 19, Figure 3 The emission wavelength control unit 28 is replaced by a radio frequency control unit 29 for controlling the transmission of radio waves. Figure 3 The distance light receiving element 32 is replaced by the distance radio wave receiving element 33, Figure 3 The received light intensity acquisition unit 42 is replaced by a received light intensity acquisition unit 43.

[0072] Fig.14 The distance-based radio wave transmitting element 19 as an element for transmitting electromagnetic waves has the same function as that of Figure 3 The distance is similar to that of the light emitting element 18, and radio waves (a type of electromagnetic waves) are emitted from the camera 16 of the reader 12 or the periphery of the camera 16. Fig.14 The radio frequency control unit 29 has the same function as the radio frequency control unit 29 in addition to processing radio waves instead of infrared rays. Figure 3 The light emission wavelength control unit 28 has the same function as that of the light emission wavelength control unit 28, and controls the frequency of the radio wave emitted from the distance radio wave transmitting element 19. Fig.14 The distance receiving element 33 as an element for receiving electromagnetic waves has the same function as that of the electromagnetic wave receiving element 33 except that it processes the electromagnetic waves instead of the infrared rays. Figure 3 The distance light receiving element 32 has the same function as that of the distance light receiving element 32, and receives the radio wave from the distance radio wave transmitting element 19 of the reader 12. Fig.14 The receiving intensity acquisition unit 43 has the same function as Figure 3 The light receiving intensity acquisition unit 42 has the same function as that of the distance radio wave receiving element 33, and acquires the reception intensity of the radio wave from the reader 12 (distance radio wave transmitting element 19). Fig.14 The light intensity control unit 40 changes the light intensity of the light source 30 according to the reception intensity obtained by the reception intensity acquisition unit 43. In addition, the radio waves transmitted by the distance radio wave transmitting element 19 of the reader 12 may be, for example, radio waves such as Wifi (registered trademark) and Bluetooth (registered trademark) Low Energy. In the other embodiments described above, the same effects as those in the embodiment in which the reader (distance light emitting element) emits infrared rays for the tag can also be obtained.

[0073] In each of the above-described embodiments, the light source 30 of the tag 14 emits infrared rays, and the electromagnetic wave transmitting element (the distance light emitting element 18, the distance radio wave transmitting element 19) of the reader 12 emits infrared rays or radio waves. However, the light source 30 of the tag 14 may also emit visible light (a type of electromagnetic wave) instead of infrared rays, and similarly, the electromagnetic wave transmitting element of the reader 12 may also emit visible light instead of infrared rays or radio waves.

[0074] In addition, in each of the above-described embodiments, the recognition device 20 (see Figure 3 , Fig.14 ) recognizes the tag 14 from the camera image and determines the position of the tag 14. However, the tag recognition unit 26 may recognize the tag 14 from the camera image but does not determine the position of the tag 14. In this specification, "recognition of a tag (light-emitting device)" includes recognizing a tag from a camera image, but may not include determining the position of the tag. "Tag recognition system (light-emitting device recognition system)" includes a system that recognizes a tag (light-emitting device) from a camera image but does not determine the position of the tag (light-emitting device).

[0075] In the above embodiments, the processor refers to a processor in a broad sense, including a general-purpose processor (such as CPU: Central Processing Unit, etc.) and a dedicated processor (such as GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0076] In addition, the actions of the processors in the above-mentioned embodiments are not only performed by one processor, but can also be performed by multiple processors located in physically separated positions in cooperation. In addition, the order of the actions of the processors is not limited to the order described in the above-mentioned embodiments, and can also be appropriately changed.

Claims

1. A light emitting device recognition system, comprising: A light emitting device having a light source that flashes according to identification information inherent to the self-luminous device; A camera device for capturing light from the light source of the light emitting device; an identification device for identifying the light emitting device based on the light of the light source of the light emitting device appearing in the captured image of the camera device; as well as an electromagnetic wave transmitting element that emits electromagnetic waves from the imaging device or the periphery of the imaging device, The light emitting device further comprises an electromagnetic wave receiving element, which receives the electromagnetic wave from the electromagnetic wave transmitting element. The greater the intensity of the electromagnetic wave received by the electromagnetic wave receiving element, the smaller the light intensity of the light source caused by the light emitting device. The light-emitting device recognition system includes a plurality of combinations of the camera device and the electromagnetic wave transmitting element. The electromagnetic waves emitted by the plurality of electromagnetic wave transmitting elements have different central wavelengths. The light emitting device changes the light emission intensity of the light source according to the electromagnetic wave having the maximum intensity among the plurality of electromagnetic waves received by the electromagnetic wave receiving element. The electromagnetic wave having the maximum intensity is received from the electromagnetic wave transmitting element closest to the light emitting device.

2. The light emitting device recognition system according to claim 1, wherein: The light of the light emitting device is a first infrared ray, The electromagnetic wave of the electromagnetic wave transmitting element is a second infrared ray having a central wavelength different from that of the first infrared ray.

3. The light emitting device recognition system according to claim 1, wherein: The light of the light emitting device is infrared light, The electromagnetic wave of the electromagnetic wave transmitting element is a radio wave.

4. A light emitting device recognition system, comprising: A light emitting device having a light source that flashes according to identification information inherent to the self-luminous device; A camera device for capturing light from the light source of the light emitting device; an identification device for identifying the light emitting device based on the light of the light source of the light emitting device appearing in the captured image of the camera device; as well as an electromagnetic wave transmitting element that emits electromagnetic waves from the imaging device or the periphery of the imaging device, The light emitting device further comprises an electromagnetic wave receiving element, which receives the electromagnetic wave from the electromagnetic wave transmitting element. The greater the intensity of the electromagnetic wave received by the electromagnetic wave receiving element, the smaller the light intensity of the light source caused by the light emitting device. The light-emitting device recognition system includes a plurality of combinations of the camera device and the electromagnetic wave transmitting element. The electromagnetic waves emitted by the plurality of electromagnetic wave transmitting elements have different central wavelengths. The light emitting device changes the light emission intensity of the light source according to the electromagnetic wave having the second largest intensity among the plurality of electromagnetic waves received by the electromagnetic wave receiving element. The electromagnetic wave having the second largest intensity is received from the electromagnetic wave transmitting element that is second closest to the light emitting device.

5. A light emitting device used in a light emitting device identification system, comprising a light source that flashes according to identification information inherent in the light emitting device, The light-emitting device recognition system includes: a camera device that captures light from the light source of the light-emitting device; a recognition device that recognizes the light-emitting device based on the light from the light source of the light-emitting device that appears in the captured image of the camera device; and an electromagnetic wave transmitting element that emits electromagnetic waves from the camera device or the periphery of the camera device. The light emitting device includes an electromagnetic wave receiving element, which receives the electromagnetic wave from the electromagnetic wave transmitting element. The greater the intensity of the electromagnetic wave received by the electromagnetic wave receiving element, the smaller the light intensity of the light source caused by the light emitting device. The light-emitting device recognition system includes a plurality of combinations of the camera device and the electromagnetic wave transmitting element, and the electromagnetic waves emitted by the plurality of electromagnetic wave transmitting elements have different central wavelengths. The light emitting device changes the light emission intensity of the light source according to the electromagnetic wave having the maximum intensity among the plurality of electromagnetic waves received by the electromagnetic wave receiving element. The electromagnetic wave having the maximum intensity is received from the electromagnetic wave transmitting element closest to the light emitting device.

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