CN115184760A - Pixel point detection method of LED display array, computing equipment and storage medium - Google Patents

Abstract

The invention discloses a pixel point detection method of an LED display array, wherein the LED display array comprises a first LED unit and a second LED unit, the driving voltage of the first LED unit is set to be positive bias for emitting light, and the driving voltage of the second LED unit is set to be zero bias or negative bias for generating light current after absorbing light, and the method comprises the following steps: driving a first LED unit which is spaced from a second LED unit by a preset distance to emit light, and measuring the magnitude of photocurrent generated by the second LED unit; and judging whether the magnitude of the photocurrent generated by the second LED unit is within an estimated range, if so, determining that the first LED unit is a qualified pixel point, otherwise, determining that the first LED unit is an unqualified pixel point. According to the scheme, whether the pixel points in the LED display array are qualified or not can be detected in real time, the position of the dead point is determined, the dual characteristics of light emitting and detection of the LED can be fully exerted, extra detection equipment is not needed, and the detection cost is reduced.

Description

Pixel point detection method of LED display array, computing equipment and storage medium

Technical Field

The invention relates to the technical field of semiconductor devices, in particular to a pixel point detection method of an LED display array, computing equipment and a storage medium.

Background

Micro light emitting diode (Micro-LED) display technology is considered as a new generation of display technology due to its advantages of self-luminescence, high brightness, high efficiency, high stability, high integration, low power consumption, etc. At present, there are three main methods for realizing Micro-LED full-color display, including epitaxial growth, in which quantum wells with different light-emitting wavelengths are grown on the same epitaxial wafer by a growth technology to realize wide-spectrum emission from blue light to red light; color conversion, namely combining the Micro-LED with a fluorescent material to form three primary colors for luminescence; and (4) carrying out bulk transfer, and integrating Micro-LEDs with different light emitting wavelengths on one driving substrate by using a transfer technology. However, no matter what way, the problem of dark spots or even dead spots during screen display is unavoidable, and especially, the mass transfer needs to be performed for multiple times, the amount of chips to be transferred is huge, and the accuracy requirement of the transfer position is high, so that the phenomena of chip damage and the like often occur in the mass transfer process, thereby affecting Micro-LED display. Furthermore, during use of the display, certain pixels of the Micro-LED display array may age or even be damaged due to environmental or usage time increases, etc. Therefore, the method is very important for repairing the bad pixels displayed in time and detecting the dead pixel position of the Micro-LED display array in time.

The LED detection technology commonly used at present mainly detects dead pixels of the whole screen by electroluminescence test, a high-pixel camera, a microscope and a spectrometer are arranged, and the current analysis luminescence condition is sequentially carried out. However, as the market demands for display quality are increasing, the number of display pixels is increasing, the size of the pixels is decreasing, the difficulty in timely detecting the dead pixel is increasing, and the production cost is high. Therefore, it is necessary to develop a new test method to improve the detection speed and cost.

The prior art one is a chinese patent with patent publication No. CN113740036a, which discloses a huge amount detection device, comprising a laser, an optical system and an electrical test platform, wherein the laser is used for irradiating a Micro-LED chip to be detected to generate a photo-generated current, and the electrical test platform detects the generated photo-generated current; the optical test platform focuses fluorescence generated by exciting the Micro-LED by laser through a lens, a microscope and the like, and analyzes the light-emitting wavelength and the light-emitting brightness so as to detect the light-emitting characteristics. The scheme has the defects that the device is complex, the cost of the whole detection system is high, the size and the power consumption of the whole system are increased by detecting the dead pixel of the screen through the additional detection system, the robustness is reduced, the inherent advantages of the LED are weakened, and certain instantaneity is lacked.

The second prior art is a chinese patent with patent publication No. CN113009251a, which discloses a visual inspection method for dead pixels of an LED display terminal. The method comprises the steps of collecting images of an LED display terminal by a camera, correcting the images, carrying out image enhancement, image edge detection, single pixel filling, determining single centroid coordinates and the like, and determining the position of a dead point by measuring and comparing fixed values of centroid distances and distances between lamp beads. The scheme is that a mathematical image processing technology and a binary classification algorithm are adopted to identify dead pixels of the LED display terminal. For Micro-LEDs with an increasing number of display pixels and with pixel size reduction in the order of micrometers, it is difficult to ensure the accuracy of edge extraction. In addition, the center coordinates of the lamp beads are determined by adopting a centroid method, so that the light spot images are uniformly distributed, and otherwise, a large error is generated.

Therefore, it is desirable to provide a method for detecting a pixel point of an LED display array, which can detect a pixel dead pixel in the LED display array in real time and determine a dead pixel position, so as to solve the above problems in the prior art.

Disclosure of Invention

In view of the above, the present invention has been made to provide a pixel point detection method of an LED display array, a computing device and a storage medium that overcome or at least partially solve the above problems.

According to an aspect of the present invention, there is provided a pixel point detection method for an LED display array, which is executed in a computing device, wherein the LED display array includes a first LED unit and a second LED unit, a driving voltage of the first LED unit is set to be a positive bias for emitting light, and a driving voltage of the second LED unit is set to be a zero bias or a negative bias for generating a photocurrent after absorbing light. In the method, first, a first LED unit spaced apart from a second LED unit by a predetermined distance is driven to emit light, and the magnitude of photocurrent generated by the second LED unit is measured. And then, judging whether the magnitude of the photocurrent generated by the second LED unit is within an estimated range, if so, determining that the first LED unit is a qualified pixel point, otherwise, determining that the first LED unit is an unqualified pixel point.

Based on the principle that photon absorption and photon emission can be realized by a quantum well, an LED display array is prepared on the same epitaxial wafer, the dual functions of a light-emitting diode and a detector can be realized under different driving conditions, a first LED unit serving as the light-emitting diode around a second LED unit serving as the detector is driven to emit light, and whether a pixel point is qualified or not is determined by judging whether a photocurrent generated by the second LED unit is in an expected fitting curve range, so that the aim of detecting the pixel dead pixel in real time is fulfilled.

Optionally, in the method according to the present invention, a first LED unit separated from a second LED unit by a first distance, a second distance, a third distance, and a fourth distance may be driven to emit light at the same current magnitude, and the magnitudes of a first photocurrent, a second photocurrent, a third photocurrent, and a fourth photocurrent generated by the second LED unit may be measured accordingly, where the first distance, the second distance, the third distance, and the fourth distance are different from each other. And then, obtaining a relation curve between the magnitude of the photocurrent generated by the second LED unit and the separation distance between the first LED unit and the second LED unit based on the corresponding relation between the first distance and the magnitude of the first photocurrent, between the second distance and the magnitude of the second photocurrent, between the third distance and the magnitude of the third photocurrent, and between the fourth distance and the magnitude of the fourth photocurrent. When the first LED unit which is separated from the second LED unit by the preset distance is driven to emit light, whether the magnitude of the photocurrent generated by the second LED unit is within the estimated range or not is judged based on the relation curve.

Alternatively, in the method according to the present invention, the second LED display unit may be disposed at an edge portion of the LED display array.

Optionally, in the method according to the present invention, the LED display array may be divided into a plurality of regions according to the size of the LED display array; randomly selecting a plurality of first LED units in each area; the method comprises the steps of analyzing electrical characteristics and optical characteristics of a plurality of first LED units, and using the first LED units meeting preset conditions as second LED units, wherein the electrical characteristics comprise volt-ampere characteristics and capacitance-voltage characteristics, and the optical characteristics comprise spectrum response characteristics and luminous intensity pointing characteristics.

Optionally, in the method according to the present invention, the first LED unit meeting the preset condition is set to be zero-biased or negative-biased as the second LED unit capable of generating the photocurrent.

Optionally, in the method according to the present invention, the LED display array is grown on a gallium nitride-based epitaxial wafer, and the substrate of the gallium nitride epitaxial wafer is any one of a sapphire substrate, a silicon carbide substrate, and a silicon substrate.

Optionally, in the method according to the invention, the LED unit is a conventional size LED or a micro LED with a size below 100 microns.

Alternatively, in the method according to the present invention, the first LED unit at the defective pixel point may be driven to emit light; and then measuring the volt-ampere characteristic of the first LED unit so as to verify unqualified pixel points.

According to another aspect of the invention, there is provided a computing device comprising: at least one processor; and a memory storing program instructions, wherein the program instructions are configured to be executed by the at least one processor, the program instructions comprising instructions for performing the above-described method.

According to yet another aspect of the present invention, there is provided a readable storage medium storing program instructions which, when read and executed by a computing device, cause the computing device to perform the above-described method.

According to the scheme of the invention, based on the principle that the quantum well can absorb photons and emit photons, the LED display array is prepared on the same epitaxial wafer by the same process, and the dual functions of light emitting and detection are realized under different driving conditions. The size of the photocurrent generated by the second LED unit serving as the detector can reflect the luminous intensity of the first LED unit, and whether the photocurrent generated by the second LED unit is within the range of an expected fitting curve is judged by driving the first LED unit around the second LED unit to emit light, so that whether pixel points are qualified is determined, and the purpose of detecting the dead pixel of the pixel in real time is achieved.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 shows a schematic diagram of a structure of an LED display array according to one embodiment of the present invention;

FIG. 2 shows a block diagram of a computing device 200, according to one embodiment of the invention;

FIG. 3 illustrates a flow chart of a pixel point detection method 300 for an LED display array according to one embodiment of the present invention;

FIG. 4 shows a graph of current-voltage characteristics of a second LED unit at different separation distances according to one embodiment of the present invention;

FIG. 5 shows a fitted graph of photocurrent generated by a second LED unit versus separation distance in accordance with one embodiment of the present invention;

FIG. 6 illustrates a comparison of qualified pixel points and unqualified pixel points to a fitted curve according to one embodiment of the invention;

fig. 7 illustrates a voltage-current characteristic diagram of a pixel point according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

The traditional LED display screen dead pixel detection method mainly depends on electroluminescence test, and the dead pixel of the whole screen is detected by sequentially adding current to each pixel and analyzing the luminescence condition through equipping a high-resolution camera, a microscope and a spectrometer. However, as the market demand for display quality is increasing, the number of display pixels is increasing, the size of the pixels is decreasing, the difficulty in timely detecting the dead pixel is increasing, and the production cost is high. The existing technical scheme provides a huge detection device comprising a laser, an optical system and an electrical test platform, and the dead pixel detection is carried out on the optical characteristics and the electrical characteristics at the same time, so that the volume, the power consumption and the cost of the whole system are increased, the robustness is reduced, and the inherent advantages of an LED are weakened; and errors of dead pixels calculated by adopting a mathematical image processing technology are difficult to judge for Micro-LED display with small size and high resolution.

In order to solve the problems in the prior art and detect the position of a dead point in an LED display screen efficiently in real time, the scheme of the invention is provided. One embodiment of the present invention provides a pixel point detection method for an LED display array, wherein the LED display array may include a number of first LED units and a number of second LED units, a driving voltage of the first LED units is set to be positively biased for emitting light, and a driving voltage of the second LED units is set to be zero biased or negatively biased for generating photocurrent after absorbing light. FIG. 1 shows a schematic diagram of a structure of an LED display array according to one embodiment of the present invention. As shown in fig. 1, the LED display array includes a certain number of first LED display units as light emitting diodes, and a certain number of second LED display units as photodetectors, which are fabricated on the same epitaxial wafer. In fig. 1, the second LED units may be disposed at the boundary of the LED array, the first LED units are arranged in a matrix form, a certain number of the LED units may be selected as the detector, and the first LED units marked by circles in fig. 1 may be used as the second LED units to achieve the detection function. The number of the first LED display unit and the second LED display unit may be the same or different, the positions may be adjacent or not adjacent, the shape and size of the LED array and the arrangement mode of each LED unit may be set according to the requirement, and the LED units may be conventional LEDs or micro LEDs with a size of less than 100 μm, which is not limited herein.

The LED display array can be grown and prepared on the same gallium nitride-based epitaxial wafer, and the substrate of the gallium nitride epitaxial wafer is any one of a sapphire substrate, a silicon carbide substrate and a silicon substrate. When a power supply positive electrode is applied to the p electrode, a power supply negative electrode is applied to the n electrode, the voltage difference between the p electrode and the n electrode is larger than a certain value (namely, starting voltage), the quantum well can serve as a p electrode injection current (the current form is expressed as a hole carrier) and n electrode injection current (the current form is expressed as an electron carrier) composite layer to realize light emission and form a light-emitting device, and the LED units are the first LED units; on the contrary, for the other part of the LED units, when the p electrode applies the negative power supply, the n electrode applies the negative power supply, or the p electrode applies the positive power supply, the n electrode applies the negative power supply, and the voltage difference between the p electrode and the n electrode is smaller than a certain value (i.e. the turn-on voltage), when the LED units are illuminated, the p electrode and the n electrode can absorb photons to generate electron and hole pairs, and the electron and hole pairs can be separated under the action of the internal electric field and are respectively collected by the n electrode and the p electrode to form a photocurrent and a photovoltage, so as to realize the function of the photodetector, that is, the part of the LED units is the second LED unit. Based on the principle, the emission spectrum and the response spectrum of the GaN-based multi-quantum well structure are overlapped, so that the GaN-based multi-quantum well structure has dual functions of photon emission and photon detection, and for the function of LED luminescence, current injection, electron injection and hole injection are respectively performed from the n layer and the p layer to the GaN multi-quantum well, and limited carriers are radiated and recombined to produce luminescence. For the function of PD detection, the GaN multiple quantum wells absorb the emitted light to form electron-hole pairs, thereby generating a photocurrent. The light emitting diode LED and the photodetector PD have the same structure, and can realize dual functions of emitting light and detecting light under different bias voltages.

According to an embodiment of the present invention, the second LED display unit may be disposed at an edge portion of the LED display array. The LED display array can be divided into a plurality of areas according to the size of the LED display array; then randomly selecting a plurality of first LED units in each area; the performance of different regions serving as pixel points of the photoelectric detector is determined to be qualified by analyzing electrical characteristics including volt-ampere characteristics, capacitance-voltage characteristics and the like and analyzing optical characteristics including spectrum response characteristics, luminous intensity pointing characteristics and the like of the plurality of first LED units. And finally, taking the first LED unit meeting the preset condition as a second LED unit, namely, setting the first LED unit meeting the preset condition as a zero bias or a negative bias to be used as the second LED unit capable of generating the photocurrent.

The method is suitable for execution in a computing device, and FIG. 2 shows a block diagram of a computing device 200 according to one embodiment of the invention. As shown in FIG. 2, in a basic configuration 202, a computing device 200 typically includes a system memory 206 and one or more processors 204. A memory bus 208 may be used for communication between the processor 204 and the system memory 206.

Depending on the desired configuration, the processor 204 may be any type of processing, including but not limited to: a microprocessor (μ P), a microcontroller (μ C), a digital information processor (DSP), or any combination thereof. The processor 204 may include one or more levels of cache, such as a level one cache 210 and a level two cache 212, a processor core 214, and registers 216. Example processor cores 214 may include Arithmetic Logic Units (ALUs), floating Point Units (FPUs), digital signal processing cores (DSP cores), or any combination thereof. The example memory controller 218 may be used with the processor 204, or in some implementations the memory controller 218 may be an internal part of the processor 204.

Depending on the desired configuration, system memory 206 may be any type of memory, including but not limited to: volatile memory (such as RAM), non-volatile memory (such as ROM, flash memory, etc.), or any combination thereof. The physical memory in the computing device is usually referred to as a volatile memory RAM, and data in the disk needs to be loaded into the physical memory to be read by the processor 204. System memory 206 may include an operating system 220, one or more applications 222, and program data 224. The application 222 is actually a plurality of program instructions that direct the processor 204 to perform corresponding operations. In some embodiments, the application 222 may be arranged to execute instructions on an operating system with the program data 224 by one or more processors 204 in some embodiments. Operating system 220 may be, for example, linux, windows, or the like, which includes program instructions for handling basic system services and for performing hardware-dependent tasks. The application 222 includes program instructions for implementing various user-desired functions, and the application 222 may be, for example, but not limited to, a browser, instant messenger, a software development tool (e.g., an integrated development environment IDE, a compiler, etc.), and the like. When the application 222 is installed into the computing device 200, a driver module may be added to the operating system 220.

When the computing device 200 is started, the processor 204 reads program instructions of the operating system 220 from the memory 206 and executes them. Applications 222 run on top of operating system 220, utilizing the interface provided by operating system 220 and the underlying hardware to implement various user-desired functions. When the user starts the application 222, the application 222 is loaded into the memory 206, and the processor 204 reads the program instructions of the application 222 from the memory 206 and executes the program instructions.

Computing device 200 also includes storage device 232, storage device 232 including removable storage 236 and non-removable storage 238, each of removable storage 236 and non-removable storage 238 being connected to storage interface bus 234.

Computing device 200 may also include an interface bus 240 that facilitates communication from various interface devices (e.g., output devices 242, peripheral interfaces 244, and communication devices 246) to the basic configuration 202 via the bus/interface controller 230. The example output device 242 includes a graphics processing unit 248 and an audio processing unit 250. They may be configured to facilitate communication with various external devices such as a display or speakers via one or more a/V ports 252. Example peripheral interfaces 244 can include a serial interface controller 254 and a parallel interface controller 256, which can be configured to facilitate communications with external devices such as input devices (e.g., keyboard, mouse, pen, voice input device, touch input device) or other peripherals (e.g., printer, scanner, etc.) via one or more I/O ports 258. An example communication device 246 may include a network controller 260, which may be arranged to facilitate communications with one or more other computing devices 262 over a network communication link via one or more communication ports 264.

A network communication link may be one example of a communication medium. Communication media may typically be embodied by computer readable instructions, data structures, program modules, and may include any information delivery media, such as carrier waves or other transport mechanisms, in a modulated data signal. A "modulated data signal" may be a signal that has one or more of its data set or its changes made in such a manner as to encode information in the signal. By way of non-limiting example, communication media may include wired media such as a wired network or private-wired network, and various wireless media such as acoustic, radio Frequency (RF), microwave, infrared (IR), or other wireless media. The term computer readable media as used herein may include both storage media and communication media.

The computing device 200 also includes a storage interface bus 234 coupled to the bus/interface controller 230. The storage interface bus 234 is coupled to the storage device 232, and the storage device 232 is adapted to store data. Example storage devices 232 may include removable storage 236 (e.g., CD, DVD, U-disk, removable hard disk, etc.) and non-removable storage 238 (e.g., hard disk drive, HDD, etc.). In the computing device 200 according to the invention, the application 222 includes a plurality of program instructions that perform the method 300.

FIG. 3 shows a flow chart of a pixel point detection method 300 for an LED display array according to one embodiment of the invention. The method 300 is suitable for being executed in a computing device (e.g., the computing device 200) and begins with step S310 of driving a first LED unit spaced apart from a second LED unit by a predetermined distance to emit light and measuring the magnitude of photocurrent generated by the second LED unit. The first LED unit which is at a certain distance from the LED unit can be randomly driven to emit light, a power supply positive electrode is applied to a p electrode of the first LED unit, a power supply negative electrode is applied to an n electrode of the first LED unit through a driving circuit which is bonded with the LED array, and the voltage difference between the p electrode and the n electrode is larger than a starting voltage. And applying a power negative electrode to the p electrode of the second LED unit, applying a power negative electrode to the n electrode or applying a power positive electrode to the p electrode and applying a power negative electrode to the n electrode, wherein the voltage difference between the p electrode and the n electrode is not more than the turn-on voltage. Thus, when the first LED unit emits light, the photocurrent generated by the second LED unit corresponds to the received light emission intensity of the first LED unit, and then the magnitude of the photocurrent generated by the second LED unit corresponds to the distance between the first LED unit and the second LED unit.

And then, executing step S320, determining whether the magnitude of the photocurrent generated by the second LED unit is within the estimation range, if so, determining that the first LED unit is a qualified pixel point, otherwise, determining that the first LED unit is an unqualified pixel point. In order to obtain a fitted curve between photocurrent and distance, a voltage-current (IV) characteristic curve of a second LED unit under excitation of a first LED unit emitting light at different distances may be obtained, and fig. 4 shows a current-voltage characteristic curve of the second LED unit at different distances according to an embodiment of the present invention. As shown in fig. 4, the voltage-current correspondence of the second LED units at the separation distances of 450 micrometers, 636.396 micrometers, 900 micrometers, 1350 micrometers, and 1909.188 micrometers were respectively tested. And then, driving a second LED unit by utilizing a-5V voltage, detecting photocurrents generated by the light emission of the first LED units at different distances, and extracting and fitting a relation curve of the distances and the photocurrents according to the currents of the second LED units at different intervals corresponding to the-5V voltage in the graph 4. In an embodiment of the present invention, the first LED unit separated from the second LED unit by a first distance, a second distance, a third distance, and a fourth distance may be driven to emit light at the same constant current, and the first photocurrent, the second photocurrent, the third photocurrent, and the fourth photocurrent generated by the second LED unit may be measured, where the first distance, the second distance, the third distance, and the fourth distance are different from each other. Then, a relation curve between the magnitude of the photocurrent generated by the second LED unit and the separation distance is obtained based on the corresponding relation between the first distance and the magnitude of the first photocurrent, between the second distance and the magnitude of the second photocurrent, between the third distance and the magnitude of the third photocurrent, and between the fourth distance and the magnitude of the fourth photocurrent. The number of tests may be increased appropriately in order to better fit the photocurrent versus distance curve. Fig. 5 shows a fitted graph of photocurrent generated by the second LED unit versus distance according to an embodiment of the invention. As shown in fig. 5, the first distance, the second distance, the third distance, and the fourth distance are 450 micrometers, 600 micrometers, 900 micrometers, and 1500 micrometers, respectively, and the distances are as uniform as possible, so that the entire distance interval can be covered, the accuracy of the fitting curve can be ensured, and the fitting curve in the entire distance range can be obtained. When the first LED unit which is spaced from the second LED unit at any distance is driven to emit light, whether the magnitude of photocurrent generated by the second LED unit is within the pre-estimation range can be judged based on the obtained relation curve, and therefore whether pixel points are qualified is judged. FIG. 6 shows a comparison of qualifying and disqualifying pixel points to a fitted curve according to one embodiment of the invention. As shown in fig. 6, the photocurrent generated by the second LED unit corresponding to the normal pixel point emitting light at the same distance is approximately overlapped with the photocurrent in the fitting curve, and the first LED unit at the distances of 450 micrometers and 900 micrometers is driven to emit light, and the photocurrent generated by the corresponding second LED unit is tested, so that the test result shows that the photocurrent corresponding to 450 micrometers is substantially overlapped with the photocurrent in the fitting curve, and the pixel point at the distance is determined to be a qualified pixel point, and the photocurrent corresponding to 900 micrometers is far away from the photocurrent in the fitting curve and exceeds the range of the pre-estimated value, and the pixel point at the distance is determined to be an unqualified pixel point.

In an embodiment of the present invention, the voltage-current characteristics of the two pixel points can be further tested, fig. 7 shows the voltage-current characteristic relationship of the pixel points according to an embodiment of the present invention, and as shown in fig. 7, a curve 7 is a voltage-current curve of an unqualified pixel point, and a curve 8 is a voltage-current curve of a qualified pixel point, and it is found that the leakage current of the unqualified pixel point is very large. The feasibility of whether the pixel points are qualified or not through the photocurrent size detection in the scheme is verified again.

According to the scheme of the invention, the distance value between the LED unit serving as the light emitting diode and the LED unit serving as the photoelectric detector can correspond to the photocurrent generated by the LED unit serving as the photoelectric detector one by one. The first LED units around the second LED units are driven to emit light, and whether the photocurrent generated by the second LED units meets the range of an expected fitting curve or not is detected, so that whether pixel points are qualified or not is determined. The detection method does not need additional detection equipment, gives full play to the dual characteristics of light emitting and detection of the LED, is simple, has low cost, and can realize real-time detection.

The various techniques described herein may be implemented in connection with hardware or software or, alternatively, with a combination of both. Thus, the methods and apparatus of the present invention, or certain aspects or portions thereof, may take the form of program code (i.e., instructions) embodied in tangible media, such as removable hard drives, U.S. disks, floppy disks, CD-ROMs, or any other machine-readable storage medium, wherein, when the program is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention.

In the case of program code execution on programmable computers, the computing device will generally include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. Wherein the memory is configured to store program code; the processor is configured to perform the method of the invention according to instructions in said program code stored in the memory.

By way of example, and not limitation, readable media may comprise readable storage media and communication media. Readable storage media store information such as computer readable instructions, data structures, program modules or other data. Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. Combinations of any of the above are also included within the scope of readable media.

In the description provided herein, algorithms and displays are not inherently related to any particular computer, virtual system, or other apparatus. Various general purpose systems may also be used with examples of this invention. The required structure for constructing such a system is apparent from the description above. Moreover, the present invention is not directed to any particular programming language. It is appreciated that a variety of programming languages may be used to implement the teachings of the present invention as described herein, and any descriptions of specific languages are provided above to disclose preferred embodiments of the invention.

In the description provided herein, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be construed to reflect the intent: that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Those skilled in the art will appreciate that the modules or units or components of the devices in the examples disclosed herein may be arranged in a device as described in this embodiment, or alternatively may be located in one or more devices different from the device in this example. The modules in the foregoing examples may be combined into one module or may be further divided into multiple sub-modules.

Those skilled in the art will appreciate that the modules in the device in an embodiment may be adaptively changed and disposed in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and furthermore they may be divided into a plurality of sub-modules or sub-units or sub-components. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Furthermore, those skilled in the art will appreciate that while some embodiments described herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the following claims, any of the claimed embodiments may be used in any combination.

Furthermore, some of the described embodiments are described herein as a method or combination of method elements that can be performed by a processor of a computer system or by other means of performing the described functions. A processor having the necessary instructions for carrying out the method or method elements thus forms a means for carrying out the method or method elements. Further, the elements of the apparatus embodiments described herein are examples of the following apparatus: the apparatus is used to implement the functions performed by the elements for the purpose of carrying out the invention.

As used herein, unless otherwise specified the use of the ordinal adjectives "first", "second", "third", etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this description, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as described herein. Furthermore, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the appended claims. The present invention has been disclosed in an illustrative rather than a restrictive sense with respect to the scope of the invention, as defined in the appended claims.

Claims (10)

1. A method for detecting a pixel point of an LED display array, wherein the LED display array comprises a first LED unit and a second LED unit, a driving voltage of the first LED unit is set to a positive bias for emitting light, and a driving voltage of the second LED unit is set to a zero bias or a negative bias for generating a light current after absorbing light, the method comprising:

driving a first LED unit which is separated from a second LED unit by a preset distance to emit light, and measuring the magnitude of photocurrent generated by the second LED unit;

and judging whether the magnitude of the photocurrent generated by the second LED unit is within an estimated range, if so, determining that the first LED unit is a qualified pixel point, otherwise, determining that the first LED unit is an unqualified pixel point.

2. The method as claimed in claim 1, wherein the step of determining whether the magnitude of the photocurrent generated by the second LED unit is within a pre-estimated range comprises:

respectively driving a first LED unit which is separated from a second LED unit by a first distance, a second distance, a third distance and a fourth distance to emit light by the same current, and correspondingly measuring the first photocurrent, the second photocurrent, the third photocurrent and the fourth photocurrent generated by the second LED unit, wherein the first distance, the second distance, the third distance and the fourth distance are different from each other;

obtaining a relation curve between the magnitude of the photocurrent generated by the second LED unit and the spacing distance between the first LED unit and the second LED unit based on the corresponding relation between the first distance and the magnitude of the first photocurrent, between the second distance and the magnitude of the second photocurrent, between the third distance and the magnitude of the third photocurrent, and between the fourth distance and the magnitude of the fourth photocurrent;

when the first LED unit which is spaced from the second LED unit by a preset distance is driven to emit light, whether the magnitude of the photocurrent generated by the second LED unit is within an estimated range or not is judged based on the relation curve.

3. The method of claim 1 or 2, wherein the second LED display unit is disposed at an edge portion of the LED display array.

4. The method according to claim 1, characterized in that it comprises:

dividing the LED display array into a plurality of areas according to the size of the LED display array;

randomly selecting a plurality of first LED units in each area;

the LED light source comprises a plurality of first LED units, wherein the plurality of first LED units are subjected to electrical characteristic and optical characteristic analysis, the first LED units meeting preset conditions are used as second LED units, the electrical characteristics comprise volt-ampere characteristics and capacitance-voltage characteristics, and the optical characteristics comprise spectrum response characteristics and luminous intensity pointing characteristics.

5. The method according to claim 4, wherein the step of using the first LED unit meeting the preset condition as the second LED unit comprises:

and setting the first LED unit meeting the preset condition as a zero bias or a negative bias to serve as a second LED unit capable of generating photocurrent.

6. The method according to claim 1, wherein the LED display array is grown on a gallium nitride-based epitaxial wafer, and the substrate of the gallium nitride epitaxial wafer is any one of a sapphire substrate, a silicon carbide substrate and a silicon substrate.

7. The method of claim 1, wherein the LED units are micro-LEDs having a size of 100 μ ι η or less.

8. The method of claim 1, further comprising:

driving a first LED unit at the unqualified pixel point to emit light;

and measuring the volt-ampere characteristic of the first LED unit so as to verify the unqualified pixel points.

9. A computing device, comprising:

at least one processor; and

a memory storing program instructions configured for execution by the at least one processor, the program instructions comprising instructions for performing the method of any of claims 1-8.

10. A readable storage medium storing program instructions that, when read and executed by a computing device, cause the computing device to perform the method of any of claims 1-8.

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