Light spot detection device and light spot detection method

Abstract

The invention discloses a light spot detection device and a light spot detection method. The device comprises a shell, an optical signal receiving unit, a processing unit and a display unit, the optical signal receiving unit, the processing unit and the display unit are arranged on the shell, the optical signal receiving unit comprises a plurality of photosensitive units arranged in an array, and the photosensitive units are divided into M groups; the device further comprises M multi-channel analog switches and M signal amplification circuits. The output ends of the plurality of photosensitive units are respectively connected to a plurality of input ends of a multi-path analog switch; the output end of the multi-path analog switch is connected to the input end of a signal amplification circuit; the output ends of the M signal amplification circuits are respectively connected to the processing unit; the processing unit is configured to control channel switching of the multi-channel analog switch, collect signals of the photosensitive units in each group in a time-sharing mode, and process the signals of each group in parallel through the M signal amplification circuits. According to the invention, the hardware scale is obviously reduced, the detection efficiency is ensured, and the problem that the cost and the performance are difficult to consider in high-density light spot detection is solved.

Description

Technical Field

[0001] This application relates to the field of optical detection technology, specifically to a spot detection device and a spot detection method. Background Technology

[0002] Spot detection has important applications in fields such as photoelectric sensor calibration, laser processing positioning, and optical system debugging. Its core lies in accurately acquiring the spatial shape distribution of the spot and its relative energy intensity information.

[0003] For spot detection devices with multiple discrete detection points, traditional signal acquisition architectures mainly employ two approaches. One approach involves configuring an independent signal amplification and acquisition channel for each photoelectric detection point. This method enables synchronous or high-speed acquisition of all detection points, but the number of analog signal conditioning circuits (such as operational amplifiers) required is proportional to the number of detection points, resulting in a large system size and high hardware costs. The other approach uses a single signal conditioning channel, connecting all detection points sequentially via a switching circuit for time-division multiplexing acquisition. While this significantly reduces the number of hardware components, the overall system detection rate (i.e., refresh rate) decreases linearly with the increase in the number of detection points because all signals from the detection points must pass serially through the same channel. This makes it difficult to meet the needs of applications requiring dynamic spots or rapid feedback.

[0004] However, the inventors discovered that the aforementioned existing technologies have the following problems in practical use: when pursuing high-density, multi-point spot detection, adopting a full-channel independent amplification scheme will result in complex circuitry and excessively high costs; while adopting a single-channel serial multiplexing scheme will sacrifice system response speed and detection efficiency. How to achieve an effective balance between limited hardware resources and system performance has become a pressing technical problem to be solved. Summary of the Invention

[0005] The purpose of this application is to provide a spot detection device and a spot detection method to solve the technical problem that existing multi-point spot detection devices cannot achieve both low hardware cost and high detection efficiency.

[0006] In a first aspect, this application provides a light spot detection device, including a housing, a light signal receiving unit, a processing unit, and a display unit disposed on the housing. The light signal receiving unit includes a plurality of photosensitive units arranged in an array, and the processing unit is used to process the electrical signals generated by the photosensitive units and control the display unit. The plurality of photosensitive units are divided into M groups, where M is an integer greater than 1; The spot detection device also includes M multiplex analog switches and M signal amplification circuits; The output terminals of the multiple photosensitive units in each group are respectively connected to the multiple input terminals of the multiplex analog switch; The output of each of the multiplexed analog switches is connected to the input of a corresponding signal amplification circuit; the outputs of the M signal amplification circuits are respectively connected to the processing unit. The processing unit is configured to control the channel switching of the M multiplex analog switches, acquire the signals of each photosensitive unit in each group in a time-division manner, and process the signals of each group in parallel through the M signal amplification circuits.

[0007] Secondly, this application provides a spot detection method, applied to the spot detection device as described in the first aspect, the spot detection method comprising: Control M multiplex analog switches to sequentially select the electrical signals of each photosensitive unit in each group in a time-division manner; The M electrical signals selected by the M multiplex analog switches are simultaneously amplified and sampled by M independent signal amplification circuits. Based on the sampling results, the display unit is driven to issue instructions.

[0008] The spot detection device and method provided in this application construct a grouped parallel acquisition circuit architecture by dividing multiple photosensitive units arranged in an array into M groups and configuring a multiplexed analog switch and an independent signal amplification circuit for each group. This architecture allows the signal acquisition process to be performed in a time-division manner within a group and in parallel manner between groups. This design can significantly reduce the number of signal amplification circuits required from being equivalent to the total number of photosensitive units to being equivalent to the number of groups M, while ensuring that all photosensitive units are effectively acquired, thereby significantly reducing hardware complexity and manufacturing costs. At the same time, since the M signal amplification circuits work in parallel, the overall acquisition rate is much higher than that of the traditional serial multiplexing scheme, effectively balancing detection efficiency and achieving an optimized balance between cost and performance.

[0009] These or other aspects of this application will become more apparent in the following description of the embodiments. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 A schematic diagram of the spot detection device provided in an embodiment of this application is shown.

[0012] Figure 2 Another schematic diagram of the spot detection device provided in the embodiments of this application is shown.

[0013] Figure 3 A flowchart of the spot detection method provided in an embodiment of this application is shown.

[0014] Figure 4 Another flowchart of the spot detection method provided in the embodiments of this application is shown. Detailed Implementation

[0015] To enable those skilled in the art to better understand the solutions of this application, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0016] In the embodiments of this application, it should be noted that, in this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0017] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0018] Furthermore, in the embodiments of this application, "multiple" refers to two or more. Therefore, in the embodiments of this application, "multiple" can also be understood as "at least two". "At least one" can be understood as one or more, such as one, two, or more. For example, including at least one means including one, two, or more, and is not limited to which ones are included. For example, including at least one of A, B, and C, then it could include A, B, C, A and B, A and C, B and C, or A and B and C.

[0019] It should be noted that in the embodiments of this application, "connection" can be understood as electrical connection. The connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0020] This application provides a light spot detection device. Figure 1 A schematic diagram of the spot detection device provided in an embodiment of this application is shown, such as... Figure 1 As shown, it includes a housing 100, an optical signal receiving unit 10 disposed on the housing 100, a processing unit 20 and a display unit 30. The optical signal receiving unit 10 includes a plurality of photosensitive units 11 arranged in an array. The processing unit 20 is used to process the electrical signals generated by the photosensitive units 11 and control the display unit 30.

[0021] The photosensitive units 11 are divided into M groups, where M is an integer greater than 1. The spot detection device also includes M multiplexed analog switches 40 and M signal amplification circuits 50. The outputs of the photosensitive units 11 in each group are connected to the inputs of a multiplexed analog switch 40; the output of each multiplexed analog switch 40 is connected to the input of a corresponding signal amplification circuit 50; and the outputs of the M signal amplification circuits 50 are connected to the processing unit 20. The processing unit 20 is configured to control the channel switching of the M multiplexed analog switches 40, acquiring the signals of each photosensitive unit 11 in each group in a time-division multiplexing manner, and processing the signals of each group in parallel through the M signal amplification circuits 50. Optionally, the time-division multiplexing acquisition means that for any detection group consisting of K photosensitive units 11, the processing unit 20 sends a periodic address control signal to the corresponding multiplexed analog switch 40, causing the switch to turn on only one of its K input channels at any given time, thereby outputting the electrical signal generated by the selected photosensitive unit 11 to the subsequent signal amplification circuit 50. The processing unit 20 cyclically changes the address signal according to a fixed timing sequence, thereby traversing all K photosensitive units 11 in the group and realizing complete acquisition of the group's signals. For example, for a group containing 8 photosensitive units 11, the processing unit 20 can control the corresponding 8-to-1 analog switch to sequentially connect channels 0 to 7.

[0022] The core function of the photosensitive unit 11 is to achieve photoelectric conversion, and it can be a photodiode or a phototransistor. The multiplexer analog switch 40 is an electronic switch used to connect a common output to one of multiple inputs under digital signal control, enabling time-division multiplexing. The signal amplifier circuit 50 is typically built based on an operational amplifier and amplifies the weak current or voltage signal generated by the photosensitive unit 11 to a range that can be precisely quantized by the analog-to-digital converter of the processing unit 20. Each amplifier circuit operates independently without interference, ensuring signal integrity during parallel processing. The processing unit 20 serves as the control core and can be a microcontroller (MCU), microprocessor (MPU), or field-programmable gate array (FPGA). One of its core tasks is to generate and output synchronous timing logic signals to control the switching of all channels of the multiplexer analog switch 40; another core task is to receive and process the analog output signals from the M signal amplifier circuits 50, typically converting them into digital values ​​using an internal or external multi-channel ADC.

[0023] The spot detection device provided in this application group N photosensitive units and multiplexes them using M multiplexed analog switches. This device requires only M signal amplification circuits instead of N. This significantly reduces the use of analog amplification chips, related peripheral components, and PCB layout space, directly lowering hardware costs and physical size. Since the M signal amplification circuits operate in parallel, data from M points can be acquired simultaneously in each acquisition cycle. Compared to the traditional purely serial solution, the overall data acquisition rate is increased by approximately M times, making the device suitable for dynamic or quasi-static spot detection scenarios where a certain detection speed is required. The number of groups M is a designable parameter; designers can flexibly adjust the value of M based on target cost, desired refresh rate, and the total number of photosensitive units N, thereby finding the optimal balance between cost and performance under specific application constraints.

[0024] It is understood that the aforementioned photosensitive unit, multiplex analog switch, processing unit, and signal amplification circuit are all general-purpose electronic components or functional modules well-known to those skilled in the art. This application does not limit their specific internal circuit structure, specific hardware model selection, or specific physical implementation. Any device capable of achieving the photoelectric conversion, signal on / off switching, signal amplification, and logic control functions described in this application can be used in this application. For example, the photosensitive unit can be a photodiode, phototransistor, or other photoelectric conversion device; the multiplex analog switch can be a discrete analog switch chip or a switch module integrated into other chips; the processing unit can be a microcontroller (MCU), digital signal processor (DSP), field-programmable gate array (FPGA), or general-purpose processor; and the signal amplification circuit can be various amplification circuits built based on operational amplifiers. The improvement focus of this application lies in the connection topology between the aforementioned functional modules and the signal processing logic implemented based on this topology, rather than the improvement of the functional modules themselves.

[0025] In some embodiments, in the spot detection device provided in this application, the total number of photosensitive units 11 is N, and the multiplexed analog switch 40 is a K-to-1 analog switch, where N = M × K, and K is an integer greater than 1. Optionally, this application embodiment has clearly defined and constrained the key parameter relationships of the above-mentioned photoelectric detection device architecture. Wherein: the total number N refers to the number of all photosensitive units 11 in the optical signal receiving unit 10, which determines the area array resolution of the detection. The number of groups M refers to the total number of groups obtained after dividing N photosensitive units 11, and its value is equal to the number of multiplexed analog switches 40 and signal amplification circuits 50 in the device. The number of multiplexed channels K refers to the number of input channels of each multiplexed analog switch 40, that is, the number of photosensitive units 11 contained in each detection group. A K-to-1 analog switch means that the switch can connect its output terminal to one of the K input terminals at a time. The parameter relationship N=M×K ensures that all detection points are assigned to each detection group without omission or repetition, and that each detection group can be served by an independent K-to-1 analog switch and signal amplification circuit, providing a clear parameterized framework for the design of the device.

[0026] The photoelectric detection device provided in this application introduces and constrains three core parameters, N, M, and K, and their relationship, allowing designers to freely select appropriate M and K values ​​under the constraints of this relationship, based on specific application requirements (such as total resolution N, target cost, and allowable physical size). For example, with a fixed total number of points N, choosing a larger M (i.e., more groups, more parallel channels) can improve the acquisition speed but increase hardware costs; conversely, choosing a larger K (i.e., reusing more points within each group) can further save hardware but reduce the acquisition speed. This parameterized design freedom allows the architecture of this application embodiment to adapt to diverse application scenarios and achieve optimal configuration between cost and performance.

[0027] In some embodiments, in the spot detection device provided in this application, N=64, M=8, and K=8. Optionally, the total number N of photosensitive units 11 is 64. For example, these 64 photodiodes can be arranged in an 8-row × 8-column square array to provide moderate spatial detection resolution. These 64 photodiodes are divided into M=8 detection groups. A natural way to divide them is to group the 8 photodiodes in each row or column, resulting in 8 groups. Correspondingly, the device is configured with 8 identical 8-to-1 analog switches (i.e., K=8). The 8 input terminals of each 8-to-1 analog switch are connected to the 8 photodiodes in one detection group. This specific configuration reduces the number of required signal amplification circuits from 64 in a fully parallel architecture to 8 through an 8-way parallel approach, resulting in significant cost savings. At the same time, compared to the traditional scheme of serially passing all 64 points through a single amplification channel, its signal acquisition speed is theoretically increased by 8 times.

[0028] In some embodiments, Figure 2 Another schematic diagram of the spot detection device provided in the embodiments of this application is shown, such as... Figure 2 As shown, the display unit 30 includes multiple indicator lights 31, and the processing unit 20 is connected to and drives the multiple indicator lights 31 through at least one decoder 60.

[0029] The processing unit 20 is also configured to control the decoder 60 to turn on or off the corresponding indicator light 31 based on the electrical signal corresponding to each photosensitive unit 11. The decoder (e.g., using a general-purpose digital logic chip 74HC138, i.e., a 3-to-8 line decoder) serves as an extension interface between the processing unit 20 and the numerous indicator lights 31. The processing unit 20 does not need to allocate an independent I / O pin for each indicator light 31; instead, it only needs to be connected to the input of the decoder 60 via a few address lines (e.g., 3 lines). The processing unit 20 calculates the address code corresponding to the indicator light that needs to be turned on or off based on its internal decision logic (e.g., comparing the signal strength of a photosensitive unit 11 with a preset threshold) and outputs the address code to the address lines of the decoder 60. After receiving the address code, the decoder 60 activates (pulls down or up) the channel uniquely corresponding to the address code among its multiple output channels, thereby directly driving the indicator light (e.g., an LED) on that channel to change its state. For example, when the processing unit 20 determines that the signal of the i-th photosensitive unit 11 is valid, it generates the logical address i (e.g., binary code) corresponding to the unit and sends it to the decoder 60. The decoder 60 then enables the i-th output channel and finally lights up the i-th indicator light.

[0030] In some embodiments, in the spot detection device provided in this application, the number of indicator lights 31 and photosensitive units 11 are equal and their logical positions correspond one-to-one. Optionally, this application explicitly defines the visualization mapping mechanism for spot information. One-to-one logical position correspondence means that the control logic inside the processing unit 20 assigns a unique logical identifier (e.g., an index number or address code) to each independent photosensitive unit 11, and also presets the same logical identifier for each independent indicator light 31 in the display unit 30. When the processing unit 20 determines that the signal collected by the photosensitive unit 11 with a specific logical identifier is valid (e.g., exceeding a threshold), it triggers a control action to illuminate the indicator lights with the same logical identifier. This correspondence is logical and defined by software or firmware, and does not strictly require that the indicator lights 31 and photosensitive units 11 be perfectly aligned in physical space. For example, the photosensitive units 11 can be arranged in an 8x8 matrix in the center of the circuit board, while the indicator lights can be arranged in a ring around the edge of the circuit board. As long as the signal from PD#1 (one of the photosensitive units) controls LED#1 (one of the indicator lights), the signal from PD#2 (one of the photosensitive units) controls LED#2 (one of the indicator lights), and so on, the "one-to-one logical position correspondence" is satisfied. This provides a high degree of flexibility for the product's appearance and structural design.

[0031] In some embodiments, the light spot detection device provided in this application has a housing 100 with a first surface and a second surface facing away from each other. A light signal receiving unit 10 is disposed on the first surface, and a display unit 30 is disposed on the second surface. This application defines an integrated physical configuration of the light spot detection device. The first surface serves as a light signal receiving surface, facing the light source under test to receive the light spot emitted by it; the second surface serves as an observation surface, for direct viewing by the user. An array of photosensitive units 11 is distributed on the light signal receiving surface, while an array of indicator lights logically corresponding to them is distributed on the observation surface. This layout spatially achieves physical separation and functional integration of signal acquisition and result indication.

[0032] In some embodiments, the spot detection device provided in this application includes a processing unit 20 comprising a microcontroller. The microcontroller has control terminals connected to multiple analog switches and analog-to-digital converter ports connected to the output terminals of signal amplification circuits. Optionally, the microcontroller generates precise timing sequences through its internal timer, periodically updating the digital signals output to the address lines of each analog switch, thereby achieving cyclic selection control of its channels. At the same time, the microcontroller uses its multi-channel analog-to-digital converter sample-and-hold circuit to synchronously sample or rapidly sample the output voltages from all M signal amplification circuits 50, and stores the obtained digital values ​​in a memory for subsequent processing (such as threshold comparison).

[0033] In some embodiments, the spectral response range of the photosensitive unit 11 in the light spot detection device provided in this application covers the 400nm to 1400nm wavelength band. Optionally, to achieve this wide-band detection capability, the photosensitive unit 11 can be a photoelectric sensor with good sensitivity in this range, such as a silicon-based PIN photodiode. The response range of silicon photodiodes typically extends from visible light (approximately 400nm-700nm) to near-infrared light (up to approximately 1100nm), and by optimizing the device structure and selecting an appropriate model, a specified range of 400nm-1400nm can be covered. The optical design of the device (e.g., without adding filters for specific wavelengths) and the circuit design (e.g., the bandwidth and noise handling of operational amplifiers) must both ensure the linearity and consistency of signal conversion within this wide wavelength band.

[0034] This application also provides a spot detection method, applied to the spot detection device described in the above embodiments. Figure 3 A flowchart of the spot detection method provided in the embodiments of this application is shown, as follows: Figure 3 As shown, the spot detection method includes: Step S100: Control M multiplexed analog switches to sequentially select the electrical signals of each photosensitive unit within each group in a time-division manner. Optionally, the processing unit generates a synchronous timing control signal and sends it to all M multiplexed analog switches. For each multiplexed analog switch, the processing unit periodically changes the digital code output to its address selection pin, causing its internal electronic switch to cyclically connect each of its K input channels. This means that within each extremely short time slice, only one specific photosensitive unit in each detection group is connected to the subsequent circuit, thus achieving time-division selection by traversing all photosensitive units within a group in chronological order. For example, when M=8 and K=8, the processing unit controls eight 8-to-1 analog switches to operate synchronously. In each scanning sub-cycle, each of the eight groups selects the first unit within its group; in the next sub-cycle, the second unit of each group is synchronously selected, and so on.

[0035] Step S200: The M electrical signals selected by the M multiplex analog switches are synchronously amplified and sampled by M independent signal amplification circuits. When the multiplex analog switches are activated, the weak photoelectric signals (usually current or low voltage) generated by the M photosensitive units are sent to their corresponding M signal amplification circuits. These signal amplification circuits operate independently and in parallel, simultaneously amplifying the received M signals and boosting them to analog voltages suitable for their range. Subsequently, the processing unit, through its internal or external integrated multi-channel analog-to-digital converter, synchronously samples or sequentially samples the M amplified analog voltages, converting them into corresponding digital signal values. The key to this process is parallel processing, which ensures that illumination information from M spatial points can be acquired simultaneously within each scanning sub-cycle, forming the basis for improving the overall acquisition throughput.

[0036] Step S300: Based on the sampling results, drive the display unit to provide indication. Optionally, the processing unit processes and analyzes the series of digital signal values ​​(corresponding to all photosensitive units) collected, and generates control instructions for the display unit based on the processing results. The indication can take many forms, such as: 1) sending a data packet containing the shape and energy data of the light spot to the host computer software via a communication interface (such as UART, USB), and having the software draw an energy distribution map; 2) directly controlling the indicator light array as defined in the above embodiment based on built-in logic to light up the indicator lights at the corresponding positions to graphically display the outline of the light spot.

[0037] In some embodiments, Figure 4 Another flowchart of the spot detection method provided in the embodiments of this application is shown, as follows: Figure 4 As shown, step S300: Based on the sampling results, drive the display unit to give an indication, including: Step S310: Compare the signal value sampled by each photosensitive unit with a preset threshold. Optionally, the processing unit sets one or more thresholds for the signal value of each photosensitive unit. This threshold can be a fixed value used to distinguish between background noise and valid light signals; it can also be a dynamic value, for example, adaptively adjusted based on ambient light or historical sampling data. The processing unit compares the digital signal value corresponding to each photosensitive unit with the threshold to determine whether the point is covered by a valid light spot. If the signal value exceeds (or equals) the threshold, the point is determined to be a valid point; otherwise, it is determined to be an invalid point or a background point.

[0038] Step S320: For photosensitive units whose signal values ​​exceed a preset threshold, generate their corresponding logical addresses. Optionally, after determining that a photosensitive unit is a valid point, the processing unit needs to determine the specific indicator light corresponding to it in the display unit. To do this, the processing unit calculates or finds a corresponding digital logical address based on the photosensitive unit's position information in the grouping architecture (e.g., which group it belongs to, which position within the group), or its preset unique index number. For example, for the nth unit in the mth group, its logical address can be encoded as a binary number (m, n).

[0039] Step S330: Input the logic address to the decoder to drive the indicator light corresponding to the photosensitive unit to light up. Optionally, the processing unit outputs the logic address generated in the previous step to the address input line of the decoder (such as the 3-to-8 decoder 74HC138) through its general-purpose input / output pins. As a digital logic chip, the decoder activates (e.g., pulls low) the output port that uniquely corresponds to the input address code among its multiple output ports. The activated output port is directly connected to the driving circuit of a specific indicator light (such as an LED), thereby lighting it up. By continuously and rapidly executing steps S310 to S330, the indicator lights corresponding to all valid points covered by the light spot will be lit up sequentially or in groups, ultimately forming a light-emitting pattern on the indicator light array that corresponds to the shape of the front light spot.

[0040] The spot detection method provided in this application divides multiple photosensitive units arranged in an array into M groups, and configures each group with a multiplexed analog switch and an independent signal amplification circuit, thus constructing a grouped parallel acquisition circuit architecture. This architecture allows the signal acquisition process to be performed in a time-division manner within a group, while in a parallel manner between groups. This design can significantly reduce the number of signal amplification circuits required from being equivalent to the total number of photosensitive units to being equivalent to the number of groups M, while ensuring that all photosensitive units are effectively acquired, thereby significantly reducing hardware complexity and manufacturing costs. At the same time, since the M signal amplification circuits work in parallel, the overall acquisition rate is much higher than that of the traditional purely serial multiplexing scheme, effectively balancing detection efficiency and achieving an optimized balance between cost and performance.

[0041] The above description, in conjunction with specific embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications and substitutions should be considered within the scope of protection of this application.

Claims

1. A light spot detection device, comprising a housing, a light signal receiving unit, a processing unit, and a display unit disposed on the housing, wherein the light signal receiving unit comprises a plurality of photosensitive units arranged in an array, and the processing unit is used to process electrical signals generated by the photosensitive units and control the display unit, characterized in that: The plurality of photosensitive units are divided into M groups, where M is an integer greater than 1; The spot detection device also includes M multiplex analog switches and M signal amplification circuits; The output terminals of the multiple photosensitive units in each group are respectively connected to the multiple input terminals of the multiplex analog switch; The output of each of the multiplexed analog switches is connected to the input of a corresponding signal amplification circuit; the outputs of the M signal amplification circuits are respectively connected to the processing unit. The processing unit is configured to control the channel switching of the M multiplex analog switches, acquire the signals of each photosensitive unit in each group in a time-division manner, and process the signals of each group in parallel through the M signal amplification circuits.

2. The spot detection device according to claim 1, characterized in that, The total number of photosensitive units is N, and the multiplex analog switch is a K-to-1 analog switch, where N = M × K, and K is an integer greater than 1.

3. The spot detection device according to claim 2, characterized in that, N=64, M=8, K=8.

4. The spot detection device according to claim 1, characterized in that, The display unit includes multiple indicator lights, and the processing unit is connected to and drives the multiple indicator lights through at least one decoder. The processing unit is further configured to control the decoder to turn on or off the corresponding indicator light according to the electrical signal corresponding to each photosensitive unit.

5. The spot detection device according to claim 4, characterized in that, The number of indicator lights is equal to the number of photosensitive units, and their logical positions correspond one-to-one.

6. The spot detection device according to claim 5, characterized in that, The housing has a first surface and a second surface facing away from each other. The optical signal receiving unit is disposed on the first surface, and the display unit is disposed on the second surface.

7. The spot detection device according to claim 1, characterized in that, The processing unit includes a microcontroller, which has a control terminal connected to the multiplex analog switch and an analog-to-digital converter port connected to the output of the signal amplification circuit.

8. The spot detection device according to claim 1, characterized in that, The spectral response range of the photosensitive unit covers the 400nm to 1400nm band.

9. A spot detection method, applied to the spot detection device as described in any one of claims 1-8, characterized in that, The spot detection method includes: Control M multiplex analog switches to sequentially select the electrical signals of each photosensitive unit in each group in a time-division manner; The M electrical signals selected by the M multiplex analog switches are simultaneously amplified and sampled by M independent signal amplification circuits. Based on the sampling results, the display unit is driven to issue instructions.

10. The spot detection method according to claim 9, characterized in that, The step of driving the display unit to issue instructions based on the sampling results includes: The signal value sampled by each photosensitive unit is compared with a preset threshold. For photosensitive units whose signal values ​​exceed the preset threshold, a corresponding logical address is generated. The logical address is input to the decoder to drive the indicator light corresponding to the photosensitive unit to light up.

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