WO2022142852A1

WO2022142852A1 - Optical communication apparatus and corresponding information transmission method

Info

Publication number: WO2022142852A1
Application number: PCT/CN2021/132045
Authority: WO
Inventors: 方俊; 牛旭恒; 王强; 李江亮
Original assignee: 北京外号信息技术有限公司
Priority date: 2020-12-29
Filing date: 2021-11-22
Publication date: 2022-07-07
Also published as: CN114697559A

Abstract

An optical communication apparatus, comprising: at least three light sources for transmitting information, the three light sources comprising a first light source, a second light source, and a third light source; and a controller configured to control the light-emitting mode of the three light sources to jointly transmit at least two pieces of information, the at least two pieces of information comprising first information and second information. When the first information is transmitted, the three light sources present the same imaging at a rolling shutter imaging device, and when the second information is transmitted, the three light sources use different light-emitting modes, and present different imaging at the rolling shutter imaging device.

Description

An optical communication device and a corresponding method for transmitting information

technical field

The present invention belongs to the technical field of optical information, and more particularly relates to an optical communication device (also referred to as an "optical tag" herein) and a corresponding method for transmitting information.

Background technique

The statements in this section are merely intended to provide background information related to the present invention to assist in an understanding of the present invention. Unless explicitly stated, the contents described in this section do not constitute prior art to the technical solutions of the present application.

In the prior art, there is a method of transmitting information through light emitted by a light source, which makes the light source emit light in different ways according to the information to be transmitted, so as to transmit corresponding information. Information recognition devices, such as cell phones with cameras, can receive light from a light source and analyze it to identify the information contained within. However, when analyzing and identifying the light emitted by the light source, it is easily affected by ambient lighting conditions, interference, noise, distance, imaging equipment, etc., making it difficult to accurately identify the information transmitted by the light source, especially in complex outdoor environments. When the recognition distance is relatively long, its stability and reliability are not satisfactory, and it has not been widely used.

Therefore, there is an urgent need for an accurate and reliable method and device for transmitting information through a light source.

SUMMARY OF THE INVENTION

One aspect of the present invention relates to an optical communication device comprising: at least three light sources for transmitting information, the three light sources including a first light source, a second light source and a third light source; and a controller configured to Controlling the lighting modes of the three light sources to jointly transmit at least two kinds of information, the at least two kinds of information including first information and second information, wherein, when transmitting the first information, the three light sources are scrolling The same imaging is presented at the shutter imaging device; when the second information is transmitted, the three light sources adopt different lighting modes, and different imaging is presented at the rolling shutter imaging device.

In one embodiment, the presenting different imaging includes: the imaging of the first light source and the second light source are the same, but different from the imaging of the third light source; or the first light source is different from the imaging of the third light source. The imaging of the three light sources is the same, but different from the imaging of the second light source; or the imaging of the second light source and the third light source are the same, but different from the imaging of the first light source.

In one embodiment, the three light sources are point light sources.

In one embodiment, the projections of the three light sources on a plane orthogonal to the facing direction of the optical communication device are arranged in a straight line, and the second light source is located between the first light source and the third light source .

In one embodiment, the angle between the straight line and the horizontal direction is between 35 degrees and 55 degrees.

In one embodiment, in the projection of the three light sources on a plane orthogonal to the facing direction of the optical communication device, a line connecting the projection of the first light source and the projection of the second light source is the same as the projection of the second light source. The included angle between the projection of the third light source and the line connecting the projection of the second light source is not less than 45 degrees.

In one embodiment, when the first information is transmitted, the three light sources are made to emit light by the following methods: driving the three light sources with a DC signal; or making the three light sources flash at a high frequency, and the The driving signal period of the three light sources is less than the row exposure time of the rolling shutter imaging device.

In one embodiment, when the second information is transmitted, the first light source and the third light source emit light in the same way at any moment, and the second light source is in the same manner as the first light source and the third light source. Light sources emit light in different ways.

In one embodiment, the driving signals of the first light source and the third light source have the same frequency and phase, and the driving signal of the second light source has the same frequency and phase as the first light source and the third light source. The drive signals have the same frequency and opposite phase.

In one embodiment, when the second information is transmitted, any one of the three light sources is switched between the first state and the second state at a certain frequency by a driving signal, and at any time, The first light source and the third light source are in the same state, and the second light source is in another state.

In one embodiment, the half periods of the driving signals of the three light sources are greater than the maximum exposure time difference between the first light source and the third light source.

In one embodiment, the method further includes: when transmitting the first information, the three light sources use the same lighting mode in the following manner: the three light sources use the same lighting color; and/or the three light sources use the same lighting color; Each light source uses the same luminous intensity.

Another aspect of the present invention relates to an optical communication system, comprising: the above-mentioned optical communication device; and a rolling shutter imaging device that captures images of the optical communication device, wherein when the three of the optical communication devices are When the three light sources exhibit the same image, it is determined that the three light sources are transmitting the first information; when the three light sources in the optical communication device exhibit different images, it is determined that the three light sources are transmitting the first information. the second information.

In one embodiment, when the rolling shutter imaging device captures the imaging of the optical communication device, the imaging time of the second light source is between the imaging time of the first light source and the third light source.

Another aspect of the present invention relates to a method for transmitting information through the above-mentioned optical communication device, the method comprising: using the controller to control the lighting modes of the three light sources to jointly transmit at least two kinds of information, the at least two The information includes first information and second information, wherein when the first information is transmitted, the three light sources are made to present the same image at the rolling shutter imaging device, and when the second information is transmitted, all the light sources are made to exhibit the same image. The three light sources adopt different lighting modes, and present different images at the rolling shutter imaging device.

In the present invention, by using an optical communication device including at least three light sources and controlling its light-emitting mode, when the second information is transmitted, the three light sources present different images at the rolling shutter imaging device at any time, thereby effectively avoiding the The information misjudgment caused by the line-by-line exposure of the rolling shutter imaging equipment ensures the accuracy of the information recognition.

Description of drawings

Embodiments of the present invention are further described below with reference to the accompanying drawings, wherein:

Figure 1 shows a schematic diagram of the use of relative encoding of light sources to transmit information;

FIG. 2 shows a schematic structural diagram of a CMOS imaging device;

Figure 3 shows a schematic diagram of misjudgment of information caused by using a CMOS imaging device;

FIG. 4 shows a system structure diagram of an optical communication device according to an embodiment of the present invention;

Fig. 5 shows the orientation diagram of the image acquired by the CMOS imaging device;

6A shows a schematic diagram of an optical communication device according to an embodiment of the present invention;

FIG. 6B shows a schematic diagram of a light source driving signal for driving the light source shown in FIG. 6A according to an embodiment of the present invention;

Fig. 7 is a schematic diagram showing that an optical communication device according to an embodiment of the present invention can avoid information misjudgment;

FIG. 8 shows a schematic diagram of an optical communication device according to another embodiment of the present invention;

FIG. 9 shows a method for transmitting information through an optical communication device according to an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings through specific embodiments.

In order to improve the stability and reliability of optical communication, a method of using two light sources for relative encoding to transmit information is proposed. For transmitting the first information; for transmitting the second information when the two light sources are in different working modes (for example, only one emits light).

Figure 1 shows a schematic diagram of the use of relative encoding of light sources to transmit information. The first light source driving signal and the second light source driving signal have the same frequency and are respectively used to drive the first light source and the second light source to perform relative encoding using the two light sources. As shown in FIG. 1 , when the first information needs to be transmitted, the first light source driving signal and the second light source driving signal can be configured to always be in the same phase within a period of time (for example, a high level indicates light emission, and a low level indicates no light emission), The two light sources are made to emit light or not to emit light at any time in the time period, so as to transmit the first information. When the second information needs to be transmitted, the first light source driving signal and the second light source driving signal shown in FIG. 1 can be configured to be always inverted in a period of time, that is, at any time in the period of time, the two Only one of the light sources always emits light to transmit the second information.

The time period for transmitting the first information or the second information can for example be set to 40 milliseconds, so that the first light source and the second light source can transmit information 25 times per second, correspondingly, the imaging device can be configured for the first light source every second 25 or more images are acquired with the second light source. In each time period, the first light source driving signal and the second light source driving signal may, for example, continuously switch between high and low levels. The frequencies of the first light source driving signal and the second light source driving signal may be set to, for example, 1000 Hz, so as to prevent the human eye from feeling the flickering phenomenon.

The information identification device can use an imaging device (eg, a camera) to capture the images of the two light sources at any one time, and determine the two light sources by analyzing and comparing the images of the two light sources (rather than analyzing the images of a single light source separately) The information transmitted by the light source, which greatly reduces the influence of ambient lighting conditions, interference, noise, etc., so it can improve the accuracy and stability of the identification of the information transmitted by the light source, especially suitable for long-distance identification and complex recognition in the environment.

However, at present, some of the imaging devices configured with the information identification devices are rolling shutter imaging devices, such as CMOS imaging devices. Since the image-sensitive units in this type of equipment mostly use a line-by-line exposure method, there is a certain delay between each line, which may lead to misjudgment of information. In the following, a CMOS imaging device is taken as an example for description, but it can be understood that the solution of the present application is also applicable to any other type of rolling shutter imaging device.

FIG. 2 shows a schematic structural diagram of a CMOS imaging device. As shown in FIG. 2, a CMOS imaging device includes an array of image-sensitive cells (also called image sensors) and some other elements. The image sensor array may be an array of photodiodes, each image sensor corresponding to a pixel. Each column of image sensors corresponds to a column amplifier, and the output signal of the column amplifier is then sent to an A/D converter (ADC) for analog-to-digital conversion, and then output through an interface circuit. For any image sensor in the image sensor array, it is first cleared at the beginning of exposure, and then the signal value is read out after the exposure time has elapsed.

CMOS imaging devices usually use a rolling shutter imaging method. In a CMOS imaging device, data readout is serialized row by row, so clearing/exposure/readout can only be performed row by row in a pipeline-like manner, and all rows of the image sensor array are processed. Then combine it into one frame image. Therefore, the entire CMOS imaging device is actually exposed line by line (in some cases, the CMOS imaging device may also use a way of exposing multiple lines together at a time), which results in a small time delay between each line. If the imaging positions of the two light sources on the imaging device are not in the same row, the two light sources may not be imaged at the same time, resulting in possible misjudgment by the information recognition device during recognition.

FIG. 3 shows a schematic diagram of misjudgment of information caused by using a CMOS imaging device. As shown in FIG. 3, for the first light source and the second light source mentioned above, although the driving signal of the first light source and the driving signal of the second light source are always in the same phase when the first information is transmitted (for example, a high level indicates Lighting, low level means no light), but due to the line-by-line exposure characteristics of the CMOS imaging device, the CMOS imaging device images the first light source at time t1, and then images the second light source at time t2 later, resulting in a CMOS imaging device. In the imaging of the two light sources on the imaging device, only one light source emits light, so it is considered that the first light source and the second light source transmit the second information at the moment, not the first information, so a misjudgment occurs. In addition, when the light source is imaging at the rising or falling edge of the driving signal, information misjudgment may also be caused. Likewise, when the first light source and the second light source are transmitting the second information, misjudgment may also be caused due to the line-by-line exposure characteristic of the CMOS imaging device.

The above-mentioned misjudgment can be avoided or overcome by physical design or coding design of the light source, for example, the imaging positions of the two light sources are located in approximately the same row, or by introducing a check digit into the coding, etc., but this will cause Some restrictions or affect the efficiency of information transmission.

In this regard, the present invention provides an optical communication device comprising at least three light sources and a controller, which transmits various kinds of information by controlling the lighting modes of the three light sources. The optical communication device is also referred to herein as an "optical tag", the two being used interchangeably throughout this application.

FIG. 4 shows a system structure diagram of an optical communication device according to an embodiment of the present invention. It should be noted that FIG. 4 is only for illustrating components (eg, light sources) included in the optical communication device, and is not intended to limit the shape, size, position, etc. of each component in any form. As shown in FIG. 4 , the optical communication device includes three light sources and a controller (not shown), wherein the three light sources include a first light source, a second light source and a third light source; the controller is configured to control the three light sources The first information and the second information are transmitted together, wherein when the first information is transmitted, the three light sources present the same image at the CMOS imaging device (for example, all three light sources are bright), and when the second information is transmitted, the three light sources are The two light sources present different images at the CMOS imaging device (eg, two light sources are bright, one light source is dark; or vice versa).

In this application, the attribute of light refers to any attribute that can be recognized by an imaging device. For example, it can be the intensity, color, wavelength and other attributes of light that can be perceived by the human eye, or can be other attributes that cannot be perceived by the human eye, such as The intensity, color, or wavelength, etc., of an electromagnetic wave that is outside the visible range of the human eye, or any combination of the above properties. Thus, information can be conveyed using a single property of light or a combination of properties. When using the intensity properties of light to transmit information, this can be done simply by choosing a high or low level. In the following, for the sake of simplicity, different states of the light source are represented by a high level or a low level, but those skilled in the art can understand that other ways of utilizing the properties of light are also feasible. It should be noted that, when the first information is transmitted, the properties of the light of the three light sources may be the same or different from the properties of the light of the three light sources when the second information is transmitted.

When the light source is transmitting information, a CMOS imaging device or a device having a CMOS imaging device (collectively referred to as "CMOS imaging device" in the present invention), such as a mobile phone, tablet computer, smart glasses, etc., can be used to image the light source, that is, Imaging by rolling shutter to identify the information transmitted by the light source. In the following, a mobile phone is taken as an example of a CMOS imaging device for description.

FIG. 5 shows a directional diagram of an image acquired by a CMOS imaging device. As shown in FIG. 5 , the direction of the scanning line of the mobile phone (that is, the direction of the lines imaged at the same time) is the vertical direction, but those skilled in the art can understand that the direction of the scanning line may also be different depending on the underlying hardware configuration. horizontal direction.

The light source may be any form of light source, as long as one of its states that can be sensed by the imaging device can be changed at different frequencies. In one embodiment, the above three light sources may be point light sources and controlled by the controller.

In one embodiment, the projections of the three light sources included in the optical label on a plane orthogonal to the facing direction of the optical label may be approximately aligned in a straight line, and the second light source is located between the first light source and the third light source. In this way, when the CMOS imaging device is used to photograph the optical label, the images of the three light sources on the CMOS imaging device are also roughly arranged in a straight line, and the images of the second light source are located between the images of the first light source and the third light source. In the process of scanning by a user using a device (eg, a mobile phone), it is most common to hold the device horizontally or vertically, corresponding to a generally horizontal or generally vertical scan line direction, respectively. In order to take into account the horizontal and vertical scanning line directions, in one embodiment, the included angle between the above-mentioned straight line and the horizontal direction may be between 35 degrees and 55 degrees, for example, approximately 45 degrees.

FIG. 6A shows a schematic diagram of an optical communication device according to an embodiment of the present invention. As shown in FIG. 6A , the optical label 600 includes three point light sources, namely a first light source 601 , a second light source 602 and a third light source 603 , wherein the second light source 602 is located between the first light source 601 and the third light source 603 and the projections of the three light sources on a plane orthogonal to the facing direction of the optical label 600 are roughly arranged in a straight line.

In one embodiment, when transmitting the first information, the three light sources may always be made to present the same image at the imaging device (eg, all three light sources are bright). In one embodiment, when the second information is transmitted, the first light source and the third light source can be caused to emit light in the same way at any time, and the second light source can be caused to emit light in a different way from the first light source and the third light source. For example, the driving signals of the first light source and the third light source can be made to have the same frequency and phase, so that at any moment, the first light source and the third light source emit light in the same way, and the driving signal of the second light source can be made to have the same frequency and phase as the third light source. The driving signals of one light source and the third light source have the same frequency, but cause the second light source to emit light in a different way than the first light source and the third light source at any one time. For example, the driving signal of the second light source may be made to have an opposite phase to the driving signals of the first light source and the third light source. In one embodiment, when the second information is transmitted, any one of the three light sources can be switched between the first state and the second state at a certain frequency through a driving signal, and at any moment, the first state One light source and the third light source are in the same state, while the second light source is in another state.

FIG. 6B shows a schematic diagram of a light source driving signal for driving the light source shown in FIG. 6A according to an embodiment of the present invention.

As shown in FIG. 6B , when the first information is transmitted, a DC driving signal may be provided to the three light sources, that is, the light source driving signals of the three light sources are always at a high level, so that the three light sources are located at the imaging device. images are bright. It will be appreciated that the light source can be imaged bright in a number of ways. In one embodiment, a DC drive signal may be provided to the light source. In another embodiment, the light source can be made to flicker at a high frequency, wherein the flicker period (a high level and a low level form a flicker period, which may also be referred to as a "driving signal period" in the present invention) is smaller than that of the imaging device. The line exposure time, so that in each line exposure, the corresponding light source is bright and dark at least once, so that the image is bright.

When transmitting the second information, the driving signals of the three light sources may have the same frequency, the driving signals of the first light source and the third light source may have the same phase, and the driving signals of the second light source may have the same frequency as the first light source or the third light source. the opposite phase of the drive signal.

FIG. 7 is a schematic diagram showing that an optical communication device according to an embodiment of the present invention can avoid information misjudgment. As shown in FIG. 7 , when the second information is transmitted, even if the first light source and the second light source present the same imaging at the CMOS imaging device due to the imaging time difference between the first light source and the second light source, the third light source will present the same image as the second light source. The first and second light sources are imaged differently. In addition, even if the exposure timings of the first light source, the second light source and the third light source (ie, times t1, t2, and t3, respectively) are moved forward or backward together (ie, the dotted line shown in FIG. 7 is shifted left or right) ), the three light sources will always present different images at the CMOS imaging device, which can include three situations, namely: (1) the imaging of the first light source and the second light source is the same, but the imaging of the third light source is the same (2) The imaging of the first light source and the third light source is the same, but different from that of the second light source; (3) The imaging of the second light source and the third light source is the same, but different from that of the first light source. In addition, when the light source is just on the rising edge or falling edge of the driving signal when imaging, it will not lead to misjudgment. In this way, information misjudgment caused by row-by-row exposure of the CMOS imaging device can be avoided, and the accuracy of information identification is ensured.

In some embodiments, the half period (eg, the duration of a high level or a low level in a blinking period) of the driving signals of the three light sources may be made greater than the maximum exposure time difference between the first light source and the third light source. In some embodiments, considering that in extreme cases, the imaging positions of the first light source and the third light source may be respectively located in the first exposed row and the last exposed row of the CMOS imaging device, or on the contrary, the driving of the three light sources may be The half period of the signal is greater than the exposure time difference between the first exposed line and the last exposed line of the CMOS imaging device. In other embodiments, the half period of the driving signal of the light source can also be set according to practical application requirements, so as to be smaller than the exposure time difference between the first exposed row and the last exposed row of the imaging device. For example, when the scanning distance is usually 2 meters away, the imaging of the entire optical communication device only occupies a small area of the CMOS imaging device, so the exposure time difference between the first light source and the third light source may be much smaller than the first exposure of the imaging device. The exposure time difference between the first and last exposed lines, and thus, the half period of the driving signal of the light source may be smaller than the exposure time difference between the first and last exposed lines of the imaging device.

In another embodiment of the present invention, the projections of the three light sources included in the optical label on a plane orthogonal to the facing direction of the optical label may not necessarily be arranged in a straight line, for example, the projection of the first light source and the projection of the second light source The included angle between the connection line between the projections of the light sources and the connection line between the projections of the third light source and the projections of the second light source is less than 180 degrees. In this way, when the scanning line direction of the CMOS imaging device that captures the image of the optical label is within the included angle range, the imaging time of the second light source is still between the imaging time of the first light source and the imaging time of the third light source, so that the present invention can be realized. the goal of. In one embodiment, the included angle may be set to be no less than 45 degrees.

FIG. 8 shows an optical communication device according to another embodiment of the present invention. As shown in FIG. 8 , the optical label 800 includes three point light sources, namely a first light source 801 , a second light source 802 and a third light source 803 . The three light sources are on a plane orthogonal to the facing direction of the optical label 800 Projected into a triangular arrangement.

The above-mentioned control of the light-emitting manner of the light source by changing the brightness of the light source is only an example, and light-emitting manners with different brightness and/or different colors can also be used. Flat can represent low brightness (in extreme cases, the brightness is 0, which is the light and dark mode).

In one embodiment, the controller may also transmit information by controlling the luminous colors of the three light sources in the light tag. In one embodiment, the three light sources can use the same light emission color to transmit the first information and present the same image at the CMOS imaging device, for example, all blue or all red; when transmitting the second information, The driving signals of the first light source and the third light source may adopt the same frequency and phase, and the first light source and the third light source emit light in the same way; the driving signal of the second light source may have the same frequency and phase as the driving signal of the first light source and the third light source. The same frequency of the signal, but at any one time, the second light source emits light in a different way than the first and third light sources, for example, at any time, the first and third light sources emit red light, and the second light source emits blue light, Or vice versa; or at any time, the first light source and the third light source emit red light, and the second light source does not emit light, or vice versa; or, at any time, the first light source and the third light source emit blue light, and the second light source does not emit light , or vice versa.

Using the above color coding scheme, light sources can be configured to transmit a variety of information. For example, the first information is transmitted when all three light sources are blue, the second information is transmitted when all are red, and the third information is transmitted when two different colors of blue and red are displayed. information, the fourth information is transmitted when red and dark are present, and the fifth information is transmitted when blue and dark are present. It can be understood that several combinations of the above information can also be selected for transmission.

Another aspect of the present invention provides a method for transmitting information using the above-mentioned optical label, the method

At least two kinds of information are jointly transmitted by controlling the light-emitting modes of at least three light sources in the optical label, wherein, when transmitting the first information, the three light sources are made to present the same image at the CMOS imaging device, and when transmitting the first information, the three light sources exhibit the same image. When there are two information, the three light sources present different images at the CMOS imaging device.

FIG. 9 shows a method for transmitting information through an optical communication device according to an embodiment of the present invention. As shown in Figure 9, the method includes:

S910, when the first information is transmitted, provide a DC drive signal to the three light sources in the optical tag, so that the three light sources present the same image at the CMOS imaging device.

In another embodiment, when the first information is transmitted, the three light sources in the optical label can be made to flicker at a high frequency, and the driving signal period of the three light sources is smaller than the row exposure time of the CMOS imaging device, so that the three light sources are The same imaging is presented at the CMOS imaging device.

S920, when transmitting the second information, control the driving signals of the first light source and the third light source to have the same frequency and phase, and the driving signals of the second light source to have the same frequency and opposite to the driving signals of the first light source and the third light source , so that the three light sources present different images at the CMOS imaging device.

In other embodiments, various kinds of information can also be transmitted by controlling whether the three light sources in the light tag emit light, the color of light and/or the brightness of light.

It should be noted that, in the present application, the three light sources have different lighting modes or different imaging does not mean that they must be different in pairs, but may include situations in which two of the light sources are the same but different from the other one.

Compared with the information transmission error caused by the line-by-line exposure characteristics of the CMOS imaging device, the optical label of the present invention performs relative encoding by controlling the lighting modes of the three light sources, and flexibly sets the frequency, phase, period and other parameters of the driving signals of different light sources. , which effectively avoids the above problems and realizes the stability and reliability of information transmission.

References in this specification to "various embodiments," "some embodiments," "one embodiment," or "an embodiment," etc., refer to specific features, structures, or properties described in connection with the embodiments, including in at least one embodiment. Thus, appearances of the phrases "in various embodiments," "in some embodiments," "in one embodiment," or "in an embodiment" in various places throughout the specification are not necessarily referring to the same implementation example. Furthermore, the particular features, structures, or properties may be combined in any suitable manner in one or more embodiments. Thus, particular features, structures, or properties shown or described in connection with one embodiment may be combined, in whole or in part, with the features, structures, or properties of one or more other embodiments without limitation, provided that the combination is not non-limiting. Logical or not working. In addition, various elements in the drawings of the present application are for illustrative purposes only and are not drawn to scale.

Having thus described several aspects of at least one embodiment of this invention, it will be appreciated that various changes, modifications, and improvements will readily occur to those skilled in the art. Such changes, modifications and improvements are intended to be within the spirit and scope of the present invention.

Claims

An optical communication device, comprising:

at least three light sources for transmitting information, the three light sources including a first light source, a second light source and a third light source; and

a controller configured to control the lighting modes of the three light sources to jointly transmit at least two types of information, the at least two types of information including first information and second information, wherein when transmitting the first information, The three light sources present the same imaging at the rolling shutter imaging device; when transmitting the second information, the three light sources adopt different lighting modes and present different imaging at the rolling shutter imaging device.
The optical communication device of claim 1, wherein said presenting different imaging comprises:

The imaging of the first light source is the same as the imaging of the second light source, but the imaging of the third light source is different; or

The imaging of the first light source is the same as the imaging of the third light source, but the imaging of the second light source is different; or

The imaging of the second light source is the same as that of the third light source, but is different from that of the first light source.
The optical communication device according to claim 1, wherein the three light sources are point light sources.
The optical communication device according to claim 3, wherein the projections of the three light sources on a plane orthogonal to the facing direction of the optical communication device are arranged in a straight line, and the second light source is located in the first light source between the light source and the third light source.
The optical communication device according to claim 4, wherein the angle between the straight line and the horizontal direction is between 35 degrees and 55 degrees.
The optical communication device according to claim 3, wherein in the projection of the three light sources on a plane orthogonal to the facing direction of the optical communication device, the projection of the first light source and the second light source The included angle between the connecting line of the projection and the connecting line of the projection of the third light source and the projection of the second light source is not less than 45 degrees.
The optical communication device according to claim 1, wherein when transmitting the first information, the three light sources are caused to emit light by:

driving the three light sources with a DC signal; or

The three light sources are made to flicker at a high frequency, and the driving signal period of the three light sources is smaller than the row exposure time of the rolling shutter imaging device.
The optical communication device according to claim 1, wherein when the second information is transmitted, the first light source and the third light source emit light in the same manner at any moment, and the second light source emits light in the same manner as the second light source. The first light source and the third light source emit light in different ways.
The optical communication device according to claim 8, wherein the driving signals of the first light source and the third light source have the same frequency and phase, and the driving signal of the second light source has the same frequency and phase as the first light source. The driving signals of the light source and the third light source have the same frequency and opposite phases.
The optical communication device according to claim 1, wherein when the second information is transmitted, any one of the three light sources is caused to be between the first state and the second state at a certain frequency by a driving signal switch, and at any one time, the first light source and the third light source are in the same state, and the second light source is in another state.
The optical communication device according to claim 9 or 10, wherein a half period of the driving signals of the three light sources is greater than a maximum exposure time difference between the first light source and the third light source.
The optical communication device according to claim 1, further comprising, when transmitting the first information, the three light sources are made to adopt the same lighting mode by the following methods:

the three light sources are of the same emission color; and/or

The three light sources use the same luminous intensity.
An optical communication system, comprising:

The optical communication device of any one of claims 1-12; and

a rolling shutter imaging device, which captures imaging of the optical communication device, wherein when the three light sources in the optical communication device exhibit the same imaging, it is determined that the three light sources are transmitting the first information; When the three light sources in the optical communication device exhibit different images, it is determined that the three light sources are transmitting the second information.
The optical communication system according to claim 13, wherein, when the rolling shutter imaging device captures the imaging of the optical communication device, the imaging time of the second light source is the imaging time of the first light source and the third light source. between time.
A method of transmitting information through the optical communication device of any one of claims 1-12, the method comprising:

Using the controller to control the lighting modes of the three light sources to jointly transmit at least two kinds of information, the at least two kinds of information include first information and second information, wherein when transmitting the first information, all the The three light sources present the same image at the rolling shutter imaging device, and when the second information is transmitted, the three light sources use different lighting modes, and present different images at the rolling shutter imaging device.