Braille recognition photoelectric sensor, Braille recognition system and Braille recognition method

Abstract

The invention discloses a braille recognition photoelectric sensor, a braille recognition system and a braille recognition method, which are used for detecting the distribution condition of salient points on a braille board. At least one gallium nitride chip, wherein the gallium nitride chip is integrated on the substrate; the lens is arranged above the gallium nitride chip in a covering manner; the gallium nitride chip is used for generating emitted light rays, the emitted light rays reach the braille plate through the lens, and the gallium nitride chip is further used for receiving reflected light rays returned by the braille plate and outputting corresponding light current signals. A monolithic integrated light emitting diode (LED)-photoelectric detector (PD) means is adopted, additional optical elements are not needed, and the device is high in light emitting and receiving efficiency and free of environmental influence. In addition, multiple array devices can be integrated to recognize different braille systems, a complex learning algorithm is not needed, the method has the advantages of being fast in dynamic response to blind spot recognition and high in repeatability, and braille distribution can be accurately recognized.

Description

Technical Field

[0001] The present invention relates to the technical field of Braille recognition, and in particular to a Braille recognition photoelectric sensor, a system and a Braille recognition method. Background Art

[0002] Braille is another channel for visually impaired people to exchange information through the sense of touch. However, Braille recognition itself requires a certain amount of learning cost, and possible tactile perception errors make the process of Braille recognition time-consuming and laborious. In order to ensure that visually impaired people can read more quickly, efficiently and reliably, it is crucial to design a Braille recognition device that is simple to operate, has stable performance, and has a high error tolerance.

[0003] The existing technologies in the field of braille recognition are mainly contact recognition detection and non-contact recognition detection. Among them, non-contact recognition detection mainly adopts a braille recognition method based on image recognition, which requires the capture of the usual braille arrangement. An optical recognition module is generally composed of a camera and a graphics processor, which is controlled by a central control unit and transmits information through a Bluetooth module, a player module, etc. After the braille pattern is captured by the camera, the graphics processor will process the captured braille pattern for recognition by the central control unit with a built-in learning algorithm.

[0004] However, the existing technology still has the following shortcomings: the electrical performance of the contact method is mainly limited by the material itself, and it is difficult to achieve high repeatability, high sensitivity, and fast dynamic response at the same time. At the same time, the contact may be affected by the surface material, dirt or wear, resulting in reduced recognition accuracy, material loss and performance degradation, affecting its recognition ability and life; the non-contact method requires an additional optical recognition module, and at the same time has high requirements for algorithm accuracy, which is easily affected by environmental factors (light source, distance, etc.), resulting in reduced recognition accuracy. Summary of the invention

[0005] In view of various problems of Braille recognition equipment in the prior art, the present invention provides a Braille recognition photoelectric sensor, system and Braille recognition method, and particularly relates to a monolithic integrated light emitting diode (LED)-photodetector (PD), which converts the scattering rate difference of the Braille surface under light into an induced photoelectric flow, and the distribution of the convex dots can be sensed by judging the change in photocurrent, thereby performing Braille recognition. At the same time, a playback module is used to receive and play the recognized Braille on a mobile terminal, so that users can read without systematically learning Braille.

[0006] The technical scheme of the present invention is as follows:

[0007] In a first aspect, the present invention provides a Braille recognition photoelectric sensor for detecting the distribution of bumps on a Braille board, wherein the Braille recognition photoelectric sensor comprises: a substrate; at least one gallium nitride chip, which is integrated on the substrate; a lens, wherein the lens cover is disposed above the gallium nitride chip; the gallium nitride chip is used to generate emission light, which reaches the Braille board through the lens, and the gallium nitride chip is also used to receive reflected light returned by the Braille board and output a corresponding photocurrent signal.

[0008] In the above technical solution, the Braille board is scanned and identified by the gallium nitride chip in the form of optical signals. There is no need to contact the Braille board or use an additional optical recognition module. It has the advantages of fast response, high accuracy and low cost.

[0009] Furthermore, the gallium nitride chip includes:

[0010] substrate; a light emitting diode and a photodetector, wherein the light emitting diode and the photodetector are arranged on the substrate at intervals.

[0011] In the above technical solution, after the emission light emitted by the light emitting diode is reflected by the Braille board, the photodetector detects the emission light reflected by the Braille board to obtain a corresponding photocurrent signal.

[0012] Furthermore, the light emitting diode and the photodetector are flip-chip mounted on the substrate.

[0013] In the above technical solution, the substrate is located above the light-emitting diode and the photodetector and serves as a waveguide, and sensing is achieved by causing a change in the distribution of the outgoing light due to a change in the refractive index.

[0014] Furthermore, the lens is an extension lens.

[0015] In the above technical solution, the response to the Braille dots can be kept consistent within 0-3 mm between the sensor and the Braille board, the structure is simple, and long-term monitoring can be achieved.

[0016] Furthermore, the substrate is a sapphire substrate.

[0017] In the above technical solution, light-emitting diodes and photodetectors of the same structure are grown on the same sapphire substrate at the same time, and the regions are isolated by etching.

[0018] Furthermore, a plurality of gallium nitride chips are provided and arranged side by side on the substrate.

[0019] In the above technical solution, the Braille distribution information is determined by simultaneously reading the distribution of convex dots in each row, thereby improving the efficiency of Braille scanning and recognition.

[0020] In a second aspect, the present invention also provides a Braille recognition system, wherein the Braille recognition sensor is connected to a control module through a transimpedance amplifier; a Braille recognition photoelectric sensor, the Braille recognition photoelectric sensor is used to output a photocurrent signal according to the reflected light returned by the Braille board; a transimpedance amplifier, connected to the Braille recognition photoelectric sensor, the transimpedance amplifier is used to amplify the photocurrent signal and output an analog voltage signal; a control module, connected to the transimpedance amplifier, the control module is used to obtain Braille information according to the analog voltage signal; a player module, connected to the control module, the player module is used to play the Braille information.

[0021] Furthermore, the Braille recognition system also includes: a Bluetooth module and a mobile terminal; wherein the Bluetooth module is connected to the control module and the mobile terminal respectively, and the Bluetooth module is used to send the Braille information to the mobile terminal; and the mobile terminal is used to display or play the Braille information.

[0022] Furthermore, the control module is a micro control unit.

[0023] In a third aspect, the present invention further provides a Braille recognition method based on the Braille recognition system described above, comprising:

[0024] Obtaining a photocurrent signal fed back by a Braille recognition photoelectric sensor and amplifying the photocurrent signal to obtain an analog voltage signal; obtaining Braille information according to the analog voltage signal;

[0025] Play the Braille information.

[0026] The present invention provides a Braille recognition photoelectric sensor, system and Braille recognition method. Compared with the prior art, the advantages of the present invention are: the present invention can rely on a single millimeter-scale chip to complete the scanning work, with low cost and small area, and is easy to integrate other electrical modules such as wireless Bluetooth modules and player modules, and can be used in portable scenarios; compared with the image recognition method, the present invention does not require additional optical components. Since a monolithic integrated light emitting diode (LED)-photodetector (PD) method is adopted, the device has high light emitting and light receiving efficiency and is not afraid of environmental influences; by integrating multiple array devices, different Braille systems can be identified without complex learning algorithms, and it has the characteristics of fast dynamic response to blind spot recognition and high repeatability, and can accurately identify Braille distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary personnel in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0028] Figure 1 A schematic diagram of a Braille scanning board.

[0029] Figure 2 This is a flow chart of the Braille recognition system of the Braille recognition photoelectric sensing system of the present invention.

[0030] Figure 3 It is a structural schematic diagram of the Braille recognition photoelectric sensor of the present invention.

[0031] Figure 4 It is a schematic diagram of the surface structure of the light-emitting diode and the photodetector bare chip of the gallium nitride chip in the Braille recognition photoelectric sensor of the present invention.

[0032] Figure 5 The figure is a flow chart of the Braille recognition method of the Braille recognition photoelectric sensor of the present invention.

[0033] The marks in the accompanying drawings are: 1, substrate; 2, gallium nitride chip; 3, lens; 4, braille board; 5, substrate; 6, light-emitting diode; 7, photodetector; d, distance between the top of the braille recognition photoelectric sensor and the braille board; 100, braille recognition photoelectric sensor; 200, transimpedance amplifier; 300, control module; 400, player module; 410, Bluetooth module; 420, mobile terminal. DETAILED DESCRIPTION

[0034] The present invention provides a Braille recognition photoelectric sensor, system and Braille recognition method. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] In the embodiments and the scope of the patent application, unless the text specifically defines the article, "a", "an", "the" and "the" may also include plural forms. If there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0036] It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can be intermediate elements. In addition, the "connection" or "coupling" used herein can include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0037] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as herein.

[0038] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0039] like Figure 1 The Braille arrangement method shown is the Braille arrangement method. In the Braille arrangement method, each square is composed of six dots, with 123 on the left from top to bottom and 456 on the right, which is called a square. Through the specific distribution of different Braille characters, Braille covers the 26 English letters and numbers 0-9. Figure 1 As shown in the figure, the white circle is a blank plane, and the black circle is the location of the braille dots. Therefore, according to the location of the dots in each braille, the blind group can identify the order of different letters by touch. According to the bulges in the black part of the figure, the first square on the braille board corresponds to the letter S in Braille, the second is U, and so on. However, braille recognition itself requires a certain learning cost, and the possible tactile perception errors make the process of readers recognizing braille time-consuming and laborious. In order to ensure that the visually impaired can read more quickly, efficiently, and reliably, it is crucial to design a braille recognition device that is simple to operate, stable in performance, and has a high error tolerance.

[0040] The inventors have found that the existing Braille recognition methods are mainly divided into contact methods and non-contact methods. Due to the multi-layer structure of human skin, physical quantities such as pressure, texture, roughness, torsion, temperature and humidity can be effectively distinguished. Contact Braille recognition is mainly achieved by biomimetic human skin, and it uses the physical deformation of the material itself caused by pressure when the blind spot is directly in contact to cause the characteristics of changes in electrical properties. Commonly used contact Braille sensors include piezoresistive pressure sensors, piezoelectric pressure sensors, capacitive pressure sensors and triboelectric pressure sensors.

[0041] a. Piezoresistive sensing method: The main mechanism uses the fact that when a piezoresistive material is subjected to vertical pressure, its resistance will change accordingly, and this resistance change can be converted into a corresponding voltage change, which can be collected by the back-end circuit components and amplified and processed. Its advantages are simple mechanism, high detection range, and easy to implement test circuit. However, the dynamic response performance of piezoresistive materials is often limited by the piezoresistive material itself, and it is impossible to achieve an extremely fast response time.

[0042] b. Piezoelectric sensing method: Piezoelectric sensors are often composed of two layers of flexible substrates with high elasticity and low Young's modulus wrapped around piezoelectric materials. When subjected to external force, the piezoelectric material deforms with the flexible substrate to produce longitudinal strain, thereby outputting piezoelectric voltage for judgment. Piezoelectric sensing has good dynamic response performance, large working bandwidth, and can resist electromagnetic interference. However, its electrical output often comes from the degree of deformation of the flexible substrate, and the contact force is largely absorbed by the flexible substrate, resulting in low force conduction efficiency, which in turn affects the sensitivity of the device.

[0043] c. Capacitive sensing method: It has high measurement accuracy, especially can measure nanometer-level micro-displacement values. At the same time, the capacitive sensor has a relatively simple structure, high sensitivity and high dynamic response speed. However, the capacitive sensor may have baseline drift phenomenon, and the electrical stability is not as good as other sensing mechanisms.

[0044] d. Triboelectric sensing method: Different from other contact sensing methods, triboelectric sensors mainly use friction electrification and electrostatic induction effects to convert mechanical stimulation into electrical energy and electrical signals, without the need for additional power supply modules, and without additional pollution to the environment. However, the selection of triboelectric materials is relatively strict, and the existing triboelectric tactile sensors have a large load resistance and a slow charge transfer rate, which affects the electrical performance.

[0045] In addition to direct contact with the detection object, non-contact Braille recognition is also a solution. The most common non-contact method is image recognition. Image recognition method: Usually, the capture of Braille arrangement requires an optical recognition module, which is generally composed of a camera and a graphics processor, controlled by a central control unit and transmits information through a Bluetooth module, a player module, etc. After the Braille pattern is captured by the camera, the graphics processor will process the captured Braille pattern for recognition by the central control unit with a built-in learning algorithm. Commonly used learning algorithm models include LBP+SVM, RestNet-101, MobileNetV2, Vit, PyramidNet, etc., which can achieve high accuracy and precision. However, image recognition methods often require additional electrical modules and more complex algorithms, and are easily affected by external factors such as light sources and distance.

[0046] Most of the previous Braille recognition devices are based on contact methods. Their performance is mainly limited by the sensing material itself and the force transmission efficiency. It is difficult to achieve fast dynamic response, high repeatability, and high sensitivity at the same time. At the same time, the selection of high-performance materials is relatively strict, the manufacturing method is not easy, and the contact method may cause loss of device performance. Non-contact methods are often based on optical recognition modules such as cameras, image recognizers, etc. and complex machine learning algorithms, which have high requirements for the training accuracy of the learning algorithm and the electrical module.

[0047] In response to the above technical problems, the present invention provides a photoelectric recognition sensor, system and Braille recognition method, which scan and recognize the Braille board in the form of light signals through a gallium nitride chip. It does not require contact with the Braille board or the use of an additional optical recognition module, and has the advantages of fast response, high accuracy and low cost.

[0048] See also Figure 2 and Figure 3 , Figure 1 , a braille recognition system in a preferred embodiment of the present invention is shown, which includes a braille recognition photoelectric sensor 100, a transimpedance amplifier 200, a control module 300, and a player module 400. The braille recognition photoelectric sensor 100 is used to output a photocurrent signal according to the reflected light returned by the braille board 4; the transimpedance amplifier 200 is connected to the braille recognition photoelectric sensor 100, and is used to amplify the photocurrent signal and output an analog voltage signal; the control module 300 is connected to the transimpedance amplifier 200, and obtains braille information according to the analog voltage signal; the player module 400 is connected to the control module 300, and is used to play the received braille information.

[0049] Specifically, the Braille recognition photoelectric sensor 100 emits an outgoing light to the Braille board 4, and the Braille board can reflect the light, thereby reflecting the light back to the gallium nitride chip. The gallium nitride chip can receive the reflected light and output two photocurrent signals, one is the photocurrent signal reflected by the Braille bumps, and the other is the photocurrent signal without the Braille bumps. The transimpedance amplifier 200 amplifies and converts the photocurrent signal output by the Braille recognition photoelectric sensor 100 and outputs an analog voltage signal to the control module 300. The photocurrent in the Braille recognition photoelectric sensor 100 is usually a weak photocurrent of the microampere level. After signal processing and amplification, it can meet the voltage threshold of the control module 300 to detect the change of light at the location. The control module 300 is provided with a reference voltage, and can compare and judge the analog voltage signals converted from the two photocurrent signals, that is, to judge whether the Braille recognition photoelectric sensor 100 scans the Braille convex point according to the analog voltage signal, and convert the Braille convex point position information into corresponding text and output it to the player module 400, wherein, when the analog voltage signal converted from the photocurrent signal is less than the reference voltage, it means that the Braille recognition photoelectric sensor passes the Braille convex point, otherwise the Braille recognition photoelectric sensor 100 does not scan the Braille convex point, and then, the control module 300 can obtain the Braille information according to the analog voltage signal, and further control the player module 400 to play the processing. It should be noted that the Braille information refers to the distribution information of the convex points on the Braille board, and the control module 300 is burned with a Braille recognition algorithm, which converts the change amount of the input analog voltage signal into the distribution information of the convex points in the Braille board 4 rows of Braille, and outputs it as an audio signal that can be played through a multimedia device. The control module 300 outputs the recognized text information through the player module 400 connected to the Braille recognition photoelectric sensor 100 circuit. The Braille recognition algorithm is a prior art and can be implemented using an existing mature algorithm program. The content of the algorithm selected is not limited here.

[0050] Please also read Figure 2 and Figure 3In some preferred embodiments, the braille recognition photoelectric sensor 100 particularly relates to a monolithic integrated light emitting diode (LED)-photodetector (PD). The emitted light is emitted from the light emitting diode 6. When the braille recognition photoelectric sensor 100 scans through the blank plane on the braille board 4, the reflected light generated by the plane is concentrated to the photodetector 7 at the focus of the lens 3, and the photoelectric irradiation there generates a photocurrent. At this time, the photodetector 7 uses the photocurrent generated by the reflected light from the blank plane as the current reference value. When the braille recognition photoelectric sensor 100 scans through the position of the braille convex dot, due to the change in the curvature of the surface of the braille convex dot, the emitted light of the light emitting diode 6 is scattered around at the convex dot, resulting in a reduction in the light reflected back into the lens 3. The change in the reflected light causes a difference between the photocurrent output by the photodetector 7 and the reference value.

[0051] In some embodiments, the control module 300 may be a microcontroller unit. For example, the Arduino Uno, an Arduino development board based on ATmega328P, may be selected to process and identify analog voltage signals. Arduino Uno is an open source, easy-to-use development board with a well-designed onboard peripheral circuit. It can be easily connected and integrated with analog voltage signal amplification circuits, player modules, etc., and the overall performance is sufficient to meet the needs of the Braille recognition system. During operation, the analog voltage signal input amplified by the transimpedance amplifier 200 is processed using the algorithm program pre-burned inside the single-chip microcomputer, and the position information of the Braille convex dots in the corresponding square Braille is recorded, and the information is sent to the player module 400 connected to the control module 300 to play to the user.

[0052] It should be noted that, in some preferred embodiments, the control module 300 can select other types of single-chip microcomputers as the microcontroller unit in the present invention. It only needs to set the voltage detection pin and the signal output end of the microcontroller to be stably connected with the transimpedance amplifier 200 and the player module 400 respectively, and record the Braille dot position information when the voltage detection pin detects the analog voltage signal threshold, and output it to the player module 400 in real time. The implementation principle is consistent with the above embodiment, so it will not be repeated here.

[0053] In some preferred embodiments of the Braille recognition optoelectronic system provided by the present invention, the Braille recognition system further includes: a Bluetooth module 410 and a mobile terminal 420. The Bluetooth module 410 is connected to the control module 300 and the mobile terminal 420 respectively, and the Bluetooth module 410 communicates wirelessly with the mobile terminal 420 to remotely send the Braille information to the mobile terminal 420; the mobile terminal is used to display or play the Braille information.

[0054] In this embodiment, in addition to selecting the player module 400 of the Braille recognition photoelectric sensor system itself, the user can also freely choose whether to receive and play the Braille recognition result information on the mobile terminal 420 according to needs, allowing the user holding the mobile terminal 420 to play remotely, which is used to play the Braille information of the Braille recognition system for specific users, thereby improving the system user experience.

[0055] Please also read Figure 3 , Figure 4 In some embodiments, the Braille recognition photoelectric sensor 100 includes: a substrate 1, a gallium nitride chip 2, and a lens 3; the gallium nitride chip 2 is integrated on the substrate 1, and the lens 3 is covered above the gallium nitride chip 2; the gallium nitride chip is used to generate emission light, and the emission light reaches the Braille board through the lens. The gallium nitride chip is also used to receive the reflected light returned by the Braille board and output a corresponding photocurrent signal.

[0056] Specifically, the substrate 1 adopts a PCB substrate, which is convenient for the module architecture of the subsequent Braille recognition system and improves the integration of the Braille recognition system. The lens 3 adopts an epitaxial lens, which can achieve the same response to the Braille convex point when the detector is at different distances d from the Braille board 4 (d=0-3mm), and has good stability and will not be disturbed by the external environment. At the same time, the lens 3 is simple in structure and can realize long-term monitoring of the photoelectric sensor. In the present invention, when the Braille recognition photoelectric sensor 100 is close to the Braille text area on the Braille board 4, the Braille convex point and the plane reflect the light emitted from the sapphire surface in the photoelectric chip differently. An integrated external lens 3 is added to focus the reflected light, and the sensitivity of the gallium nitride chip 2 to the change of the emitted light when the Braille convex point is located. In addition, the undulation of the adjacent plane of the Braille board has a high sensitivity, so that the dynamic response to the recognition of the Braille convex point is fast and the repeatability is high, which is convenient for subsequent data processing and accurate recognition of the Braille distribution.

[0057] Among them, the gallium nitride chip 2 is a monolithic integrated gallium nitride light emitting diode (LED)-photodetector (PD) chip, and the gallium nitride chip 2 is composed of a light emitting diode 6, a photodetector 7 and a substrate 5. The gallium nitride chip 2 grows the light emitting diode 6 and the photodetector 7 on the same substrate 5 at the same time, and the two are isolated from each other by etching. The light emitting diode 6 and the photodetector 7 are separated in area, but are located adjacent to each other in the gallium nitride chip 2, and have the same growth structure. The circular light emitting diode 6 area is isolated by etching at the center on the 1mm*1mm sapphire substrate 52, and the surrounding area is the photodetector 7. Due to the maturity of semiconductor technology, gallium nitride chips can be taped out at the millimeter level, which greatly reduces the device size and cost, and does not require additional optical devices.

[0058] In the specific implementation, the light emitting diode 6 area is electrically injected so that the light emitting diode 6 emits light. At this time, the light of a specific wavelength emitted by the light emitting diode 6 is reflected and absorbed by the photodetector 7 in the adjacent area on the chip, and is output as a photocurrent. The monolithic integrated light emitting diode (LED)-photodetector (PD) structure enables the gallium nitride chip 2 to simultaneously realize the light emitting function and the detection function, that is, the gallium nitride chip 2 integrates the light emitting diode 6 and the photodetector 7 on the chip at the same time, and can simultaneously generate emission light and receive the reflected light returned from the braille board 4, and convert the received light signal into the corresponding output photocurrent signal through the photoelectric reaction. It overcomes the defects of the existing photoelectric sensor design that the light emitting and light receiving elements are separated from each other, which leads to the difficulty of system integration and the error of light signal caused by the instrument orientation, and is used to ensure the effective transmission and reception of light signals in practical applications, and improve the detection accuracy and reliability of photoelectric sensors.

[0059] The working principle of the Braille recognition photoelectric sensor 100 is as follows: when the outgoing light generated by the light-emitting diode 6 scans the Braille convex dots, its curvature causes the outgoing light to be scattered on the surface of the Braille convex dots, so that the reflected light is reduced when returning to the photodetector 7, thereby reducing the photoelectric flow sensed by the gallium nitride chip. Therefore, the distribution of the Braille convex dots can be sensed by judging the change in photocurrent, and then Braille recognition can be performed. Compared with the contact method, the present invention does not have device loss, and can simultaneously achieve fast dynamic response, high sensitivity and high repeatability. The device has stable performance and can resist electromagnetic interference. It can rely on a single millimeter-scale chip to complete the scanning work. It has low cost and small area, and is easy to integrate other electrical modules, such as wireless Bluetooth modules and player modules, and can be used in portable scenarios. In addition, the gallium nitride chip has a high luminous efficiency, is less affected by the environment, and does not require complex algorithms.

[0060] Please continue reading Figure 3 The gallium nitride chip 2 is flip-chip mounted on the substrate 1 as a whole, that is, the light-emitting diode 6 and the photodetector 7 are flip-chip mounted on the substrate 1, and the substrate 5 is located above the light-emitting diode 6 and the photodetector 7 as an optical waveguide. Compared with the integrated device in the upright packaging mode, the flip-chip gallium nitride chip improves the reliability and energy conversion efficiency of the monolithic integrated light-emitting diode (LED)-photodetector (PD) structure.

[0061] Furthermore, in a preferred embodiment, the substrate 5 is a sapphire substrate, and the upper lens 3 is a high-refractive lens. By adding a high-refractive lens with a refractive index similar to that of the substrate material above the sapphire substrate, the difference in refractive index between the sapphire substrate and the lens or between the sapphire substrate and the air is reduced, and the light reflected back to the photoelectric detection area at the sapphire substrate is further reduced, so that more emitted light is emitted into the air along the lens 3, thereby improving the photocurrent conversion sensitivity of the Braille recognition photoelectric sensor in the present invention, and overcoming the defect of the large difference in refractive index between sapphire and air in the prior art. In addition, by placing the lens 3 between the sapphire lens and the air, the internal total reflection formed by the emitted light on the sapphire substrate is reduced, and the light extraction rate on the substrate 5 side is improved.

[0062] The present invention provides a preferred embodiment of a Braille recognition photoelectric sensor system. A plurality of gallium nitride chips 2 may be provided on the substrate of the Braille recognition photoelectric sensor 100, and the plurality of gallium nitride chips are arranged side by side on the substrate 1, and an integrated lens 3 is added uniformly. The spacing between the gallium nitride chips 2 corresponds to the spacing between the dot matrix of each row of Braille, and each gallium nitride chip 2 is responsible for the recognition of a single row. The Braille recognition photoelectric sensor 100 may be expanded into multiple arrays according to the Braille requirements of different regions, wherein the direction in which the plurality of gallium nitride chips 2 are arranged side by side is perpendicular to the scanning forward direction of the Braille recognition photoelectric sensor, and is used to simultaneously scan multiple rows of Braille convex dots, thereby reducing the number of times a single square of Braille needs to be scanned.

[0063] Specifically, in a preferred embodiment, three Braille recognition photoelectric sensors are integrated on the same PCB substrate to form a complete Braille recognition sensor. In the process of scanning a single square, each Braille recognition photoelectric sensor inside the complete Braille recognition sensor only needs to independently scan one of the three rows of Braille convex dot distribution. Therefore, the complete Braille recognition sensor only needs to undergo one horizontal scan to output the Braille recognition result, further improving the efficiency of Braille recognition.

[0064] See also Figure 5 Combined with Figure 2 In some preferred embodiments, the present invention further provides a Braille recognition method, comprising the steps of:

[0065] Step S100: obtaining a photocurrent signal fed back by the Braille recognition photoelectric sensor 100, and amplifying the photocurrent signal to obtain an analog voltage signal.

[0066] Specifically, the weak photocurrent signal is converted and amplified into a high-sensitivity analog voltage signal through the preamplification and main amplification circuits in the transimpedance amplifier 200. Furthermore, signal optimization processing such as noise reduction, filtering, and decoupling can be added to the photocurrent conversion signal to achieve a larger signal-to-noise ratio, improve signal stability, and improve the sensitivity of the analog voltage signal; the details are as described in the Braille recognition system, which will not be repeated here.

[0067] Step S200: obtaining Braille information according to the analog voltage signal.

[0068] Specifically, the recognition algorithm is burned into the single chip microcomputer in the control module 300, which converts the change value of the analog voltage signal into the distribution of Braille convex dots, and then recognizes the corresponding Braille signal according to the overall distribution of the convex dots inside each independent block; the details are as described in the Braille recognition system and will not be repeated here.

[0069] Step S300: Play the Braille information.

[0070] Specifically, the control module 300 outputs the Braille signal to a player module 400 of any form, or a mobile portable playback module that can realize the playback function, such as realizing remote wireless transmission, interaction and playback of the mobile terminal 420 through the Bluetooth module 410; the details are as described in the Braille recognition system and will not be repeated here.

[0071] In summary, the present invention discloses a Braille recognition photoelectric sensor, system and Braille recognition method, which have the following beneficial effects:

[0072] Compared with the contact method, the Braille recognition photoelectric sensor provided by the present invention does not have device loss, and can simultaneously achieve fast dynamic response, high sensitivity and high repeatability;

[0073] The device has stable performance and is resistant to electromagnetic interference. It can complete scanning work with a single millimeter-scale chip. It has low cost and small area. It is easy to integrate other multimedia function modules, such as wireless Bluetooth modules and player modules, and can be used in portable scenarios.

[0074] Compared with the image recognition method, the present invention does not require additional optical components. The system based on gallium nitride devices has higher efficiency, reduced size, lighter weight and better heat dissipation performance. With the maturity of semiconductor technology, gallium nitride chips can be taped out at millimeter scale, which can be used to realize monolithic integration of light emitting diodes (LEDs)-photodetectors (PDs), thereby reducing additional optical components and being free from environmental influences. At the same time, by integrating multi-array devices, different Braille systems can be recognized without complex learning algorithms;

[0075] The use of a monolithic integrated photodetector is proposed, which is different from the previous design that uses two discrete components, namely light emitting and light receiving, to reduce the loss of light transmission. The monolithic integration method plus the integrated high-refractive lens ensures the consistency and stability of Braille recognition at different measurement distances, and will not be disturbed by the external environment. It has high light emitting and light receiving efficiency and is not afraid of environmental influences. In addition, the recognition method of the monolithic integrated light emitting diode (LED)-photodetector (PD) is very flexible. A single device is responsible for the recognition of a single line. No additional operation is required. The operation is simple. It can be expanded into multiple arrays according to the Braille needs of different regions. It can recognize different Braille systems without the need for complex learning algorithms. It has the characteristics of fast dynamic response to blind spot recognition and high repeatability, and can accurately recognize Braille distribution.

[0076] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A Braille recognition photoelectric sensor for detecting the distribution of convex dots on a Braille board, characterized in that: Braille recognition photoelectric sensor includes: substrate; at least one gallium nitride chip, wherein the gallium nitride chip is integrated on the substrate; A lens, wherein the lens cover is arranged above the gallium nitride chip; The gallium nitride chip is used to generate emission light, and the emission light reaches the Braille board through the lens. The gallium nitride chip is also used to receive reflected light returned by the Braille board and output a corresponding photocurrent signal.

2. The Braille recognition photoelectric sensor according to claim 1, characterized in that: The gallium nitride chip comprises: substrate; A light emitting diode and a photodetector are arranged on the substrate with an interval therebetween.

3. The Braille recognition photoelectric sensor according to claim 2, characterized in that: The light emitting diode and the photodetector are flip-chip mounted on the substrate.

4. The Braille recognition photoelectric sensor according to claim 1, characterized in that: The lens is an extension lens.

5. The Braille recognition photoelectric sensor according to claim 2, characterized in that: The substrate is a sapphire substrate.

6. The Braille recognition photoelectric sensor according to claim 3, characterized in that: A plurality of gallium nitride chips are provided and arranged side by side on the substrate.

7. A Braille recognition system, characterized in that: include: The Braille recognition photoelectric sensor according to any one of claims 1 to 6, wherein the Braille recognition photoelectric sensor is used to output a photocurrent signal according to the reflected light returned by the Braille board; A transimpedance amplifier is connected to the Braille recognition photoelectric sensor, and is used to amplify the photocurrent signal and output an analog voltage signal; A control module connected to the transimpedance amplifier, the control module being used to obtain Braille information according to the analog voltage signal; A player module is connected to the control module, and the player module is used to play the Braille information.

8. The Braille recognition system according to claim 7, characterized in that: Also includes: Bluetooth module and mobile terminal; wherein, The Bluetooth module is connected to the control module and the mobile terminal respectively, and the Bluetooth module is used to send the Braille information to the mobile terminal; The mobile terminal is used to display or play the Braille information.

9. The Braille recognition system according to claim 7, characterized in that: The control module is a micro control unit.

10. A Braille recognition method based on the Braille recognition system according to any one of claims 7 to 9, characterized in that: include: Acquire a photocurrent signal fed back by a Braille recognition photoelectric sensor and amplify the photocurrent signal to obtain an analog voltage signal; Obtaining Braille information according to the analog voltage signal; The Braille information is played.

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