Light source driving circuit and light source system

Abstract

An embodiment of the present application provides a light source driving circuit and a light source system, including a processing module, a current setting module, a constant current driving module, a current acquisition module and a light source module; the processing module obtains a control instruction and outputs a control signal to the current setting module according to the control instruction; the current setting module receives the control signal and selects a first voltage signal corresponding to the control signal from multiple voltage signals and outputs it to the constant current driving module; the constant current driving module receives the first voltage signal and controls the operating current of the light source module according to the first voltage signal to achieve control of the light source brightness of the light source module; the current acquisition module collects the second voltage signal of the light source module, processes the second voltage signal to obtain a second digital signal, and transmits the second digital signal to the processing module; the processing module also receives the second digital signal, obtains the operating current of the light source module according to the second digital signal, and adjusts the output of the current setting module based on the operating current of the light source module.

Description

Technical Field

[0001] The present application relates to the field of machine vision, and in particular to a light source driving circuit and a light source system. Background Art

[0002] Current machine vision systems typically use a constant-current drive solution to power light sources. Generally, the output current remains constant. However, in certain applications, such as 2.5D (a transitional form between 2D and 3D) light source systems and PL (photoluminescence) detection systems, parameters such as the pulse width, output current, and flash frequency of the constant-current drive need to be adjustable in real time to further enhance the precision and compatibility of the light source. However, these constant-current drive solutions typically employ an input-controlled output control method, resulting in low light source stability. Summary of the Invention

[0003] The purpose of the embodiments of the present application is to provide a light source driving circuit and a light source system to improve the stability of the light source. The specific technical solutions are as follows:

[0004] In a first aspect, an embodiment of the present application provides a light source driving circuit, the circuit comprising:

[0005] Processing module, current setting module, constant current driving module, current acquisition module and light source module;

[0006] The processing module is connected to the current setting module and the current acquisition module respectively, the current setting module is connected to the constant current driving module, and the constant current driving module is connected to the current acquisition module and the light source module respectively;

[0007] The processing module is configured to obtain a control instruction and output a control signal to the current setting module according to the control instruction;

[0008] The current setting module is configured to receive the control signal and select a first voltage signal corresponding to the control signal from multiple voltage signals and output the signal to the constant current driving module;

[0009] The constant current driving module is configured to receive the first voltage signal and control the operating current of the light source module according to the first voltage signal, so as to control the brightness of the light source of the light source module;

[0010] The current acquisition module is configured to acquire a second voltage signal from the light source module, process the second voltage signal to obtain a second digital signal, and transmit the second digital signal to the processing module;

[0011] The processing module is further configured to receive the second digital signal, obtain an operating current of the light source module according to the second digital signal, and adjust the output of the current setting module based on the operating current of the light source module.

[0012] In a possible implementation, the circuit further includes: a temperature acquisition module;

[0013] The temperature acquisition module includes a temperature acquisition submodule and a third signal conversion submodule;

[0014] The temperature acquisition submodule is connected to the third signal conversion submodule, and the third signal conversion submodule is connected to the processing module;

[0015] The temperature acquisition submodule is configured to generate a third voltage signal corresponding to the temperature of the module to be measured, and transmit the third voltage signal to the third signal conversion submodule; wherein the module to be measured is any one of the processing module, the current setting module, the constant current driving module, the current acquisition module, and the light source module;

[0016] The third signal conversion submodule is configured to receive the third voltage signal, convert the third voltage signal into a third digital signal, and transmit the converted signal to the processing module;

[0017] The processing module is further configured to receive the third digital signal and obtain the temperature of the module to be tested according to the third digital signal.

[0018] In a possible implementation, the current setting module includes a first signal conversion submodule and a switch submodule;

[0019] The first signal conversion submodule is connected to the processing module and the switch submodule respectively, and the switch submodule is connected to the constant current driving module and the processing module respectively;

[0020] The first signal conversion submodule is configured to output multiple voltage signals to the switch submodule;

[0021] The switch submodule is configured to respond to the control signal and select a first voltage signal corresponding to the control signal from the multiple voltage signals and output it to the constant current driving module.

[0022] In one possible implementation,

[0023] The processing module is further configured to send a first digital signal to the first signal conversion submodule, wherein the first digital signal represents a voltage value of each voltage signal in the multiple voltage signals;

[0024] The first signal conversion submodule is configured to receive the first digital signal output by the processing module and set the voltage values ​​of the multiple output voltages according to the first digital signal.

[0025] In a possible implementation, the constant current driving module includes a comparison submodule, a driving submodule and a current sampling submodule;

[0026] The comparison submodule is connected to the current setting module, the current sampling submodule, and the driving submodule respectively; the driving submodule is connected to the light source module and the current sampling submodule respectively; and the current sampling submodule is connected to the current acquisition module;

[0027] The current acquisition submodule is configured to acquire a second voltage signal from the light source module and transmit the second voltage signal to the comparison submodule and the current acquisition module respectively;

[0028] The comparison submodule is configured to receive the first voltage signal and the second voltage signal, compare the first voltage signal with the second voltage signal, and output a fourth voltage signal to the driving submodule;

[0029] The driving submodule is configured to receive the fourth voltage signal and control the operating current of the light source module according to the fourth voltage signal.

[0030] In a possible implementation, the current acquisition module includes a following submodule and a second signal conversion submodule;

[0031] The following submodule is connected to the current sampling submodule and the second signal conversion submodule respectively, and the second signal conversion submodule is connected to the processing module;

[0032] The following submodule is configured to collect the second voltage signal of the light source module and output a fifth voltage signal following the second voltage signal; wherein the voltage value of the second voltage signal is equal to the voltage value of the fifth voltage signal;

[0033] The second signal conversion submodule is configured to receive the fifth voltage signal, convert the fifth voltage signal into the second digital signal, and transmit the second digital signal to the processing module.

[0034] In a possible implementation, the processing module includes a field programmable gate array (FPGA); the first signal conversion submodule includes a digital-to-analog converter; and the switch submodule includes an analog switch.

[0035] The input pins of the FPGA are connected to a control instruction source, the synchronous serial communication interface SPI interface of the FPGA is connected to the SPI interface of the digital-to-analog converter, and the output pins of the FPGA are connected to the enable pins of the analog switch in a one-to-one correspondence;

[0036] The output pins of the digital-to-analog converter are connected to the input pins of the analog switch in a one-to-one correspondence, and the output pins of the analog switch are connected to the constant current drive module;

[0037] The FPGA is configured to send a first digital signal to the digital-to-analog converter via its own SPI interface;

[0038] The digital-to-analog converter is configured to receive the first digital signal through its own SPI interface, set the voltage values ​​of the multiple output voltages according to the first digital signal, and output multiple voltage signals to the analog switch;

[0039] The FPGA is further configured to obtain a control instruction through its own input pins and output a control signal to the analog switch according to the control instruction;

[0040] The analog switch is used to respond to the control signal and select a first voltage signal corresponding to the control signal from the multiple voltage signals and output it to the constant current driving module.

[0041] In one possible implementation, the comparison submodule includes a first operational amplifier; the driving submodule includes a switch tube; the current sampling submodule includes a current sampling resistor; the follower submodule includes a second operational amplifier and a feedback resistor; and the second signal conversion submodule includes an analog-to-digital converter.

[0042] The non-inverting input terminal of the first operational amplifier is connected to the current setting module, the inverting input terminal of the first operational amplifier is connected to the second terminal of the switching tube and the first terminal of the current sampling resistor respectively, and the output terminal of the first operational amplifier is connected to the control terminal of the switching tube;

[0043] The first end of the switch tube is connected to the light source module;

[0044] The second end of the current collecting resistor is grounded;

[0045] The non-inverting input terminal of the second operational amplifier is connected to the first end of the current sampling resistor, the inverting input terminal of the second operational amplifier is connected to the second end of the feedback resistor, and the output terminal of the second operational amplifier is connected to the first end of the feedback resistor and the input pin of the analog-to-digital converter respectively;

[0046] The SPI interface of the analog-to-digital converter is connected to the processing module.

[0047] In a possible implementation, the circuit further includes a trigger module;

[0048] The trigger module is used to connect to a signal generating source, and the processing module is connected to the trigger module;

[0049] The trigger module is used to obtain an unprocessed control instruction, perform functional processing on the unprocessed control instruction to obtain the control instruction, and output the control instruction to the processing module.

[0050] In a possible implementation, the trigger module includes a high-speed optocoupler;

[0051] The input pin of the high-speed optocoupler is connected to the signal generating source, and the output pin of the high-speed optocoupler is connected to the processing module;

[0052] The high-speed optocoupler is used to obtain unprocessed control instructions, isolate the unprocessed control instructions from the processing module to obtain the control instructions, and output the control instructions to the processing module.

[0053] In a second aspect, an embodiment of the present application provides a light source system, comprising a signal generator, a power supply circuit, and the light source driving circuit described in any one of the first aspects above;

[0054] The signal generating source is connected to the light source driving circuit, and the power supply circuit is connected to the light source driving circuit;

[0055] The signal generating source is used to generate an unprocessed control instruction and send the unprocessed control instruction to the light source driving circuit;

[0056] The power supply circuit is used to provide power to each module in the light source driving circuit.

[0057] Beneficial effects of the embodiments of the present application:

[0058] An embodiment of the present application provides a light source driving circuit and a light source system, and the light source driving circuit includes: a processing module, a current setting module, a constant current driving module, a current acquisition module and a light source module; the processing module is respectively connected to the current setting module and the current acquisition module, the current setting module is connected to the constant current driving module, and the constant current driving module is respectively connected to the current acquisition module and the light source module; the processing module is used to obtain a control instruction and output a control signal to the current setting module according to the control instruction; the current setting module is used to receive the control signal and select a first voltage signal corresponding to the control signal from multiple voltage signals and output it to the constant current driving module; the constant current driving module is used to receive the first voltage signal and control the operating current of the light source module according to the first voltage signal to achieve control of the light source brightness of the light source module; the current acquisition module is used to collect a second voltage signal of the light source module, obtain a second digital signal after processing the second voltage signal, and transmit the second digital signal to the processing module; the processing module is also used to receive the second digital signal, obtain the operating current of the light source module according to the second digital signal, and adjust the output of the current setting module based on the operating current of the light source module. By setting up a current acquisition module, the voltage signal of the light source module is collected and reported to the processing module, so that the processing module can obtain the working current of the light source module. The output of the current setting module is adjusted based on the working current of the light source module to achieve closed-loop control, which can improve the stability of the light source.

[0059] Of course, it is not necessary to achieve all the advantages described above at the same time when implementing any product or method of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0061] Figure 1 A schematic diagram of the first structure of the light source driving circuit provided in an embodiment of the present application;

[0062] Figure 2 A second structural diagram of the light source driving circuit provided in an embodiment of the present application;

[0063] Figure 3 A third structural diagram of the light source driving circuit provided in an embodiment of the present application;

[0064] Figure 4 A fourth structural diagram of the light source driving circuit provided in an embodiment of the present application;

[0065] Figure 5A fifth structural diagram of the light source driving circuit provided in an embodiment of the present application;

[0066] Figure 6 A sixth structural diagram of the light source driving circuit provided in an embodiment of the present application;

[0067] Figure 7 A structural schematic diagram of a light source system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field based on this application are within the scope of protection of this application.

[0069] In machine vision systems, light sources must be coordinated with cameras to capture images of objects from multiple positions and angles. High-speed line scan cameras are commonly used in machine vision systems. To detect the distinct defect characteristics of different objects, images must be captured from different physical positions and angles, using varying light source brightness levels. This allows for different types of defect characteristics to be identified and processed. Light source brightness directly impacts image quality, which in turn affects feature extraction. Therefore, light source control plays a crucial role in machine vision systems.

[0070] Current machine vision systems typically use a constant-current drive solution to power light sources. Generally, the output current remains constant. However, in certain applications, such as 2.5D (a transitional form between 2D and 3D) light source systems and PL (photoluminescence) detection systems, parameters such as the constant-current drive's pulse width, output current, and flicker frequency require real-time adjustment to further enhance the light source's precision and compatibility. However, these constant-current drive solutions typically employ an input-controlled output control method, lacking a feedback mechanism for real-time adjustment of the light source current. This results in low light source stability.

[0071] In order to solve the above problems, the embodiment of the present application provides a light source driving circuit and a light source system. The light source driving circuit 1 provided in the embodiment of the present application is described in detail below:

[0072] See also Figure 1 , is a schematic diagram of a first structure of a light source driving circuit 1 provided in an embodiment of the present application, wherein the circuit 1 includes: a processing module 11, a current setting module 12, a constant current driving module 13, a current acquisition module 14 and a light source module 15;

[0073] The processing module 11 is connected to the current setting module 12 and the current acquisition module 14 respectively, the current setting module 12 is connected to the constant current driving module 13, and the constant current driving module 13 is connected to the current acquisition module 14 and the light source module 15 respectively;

[0074] The processing module 11 is configured to obtain a control instruction and output a control signal to the current setting module 12 according to the control instruction;

[0075] The current setting module 12 is configured to receive the control signal and select a first voltage signal corresponding to the control signal from multiple voltage signals and output the signal to the constant current driving module 13;

[0076] The constant current driving module 13 is configured to receive the first voltage signal and control the operating current of the light source module 15 according to the first voltage signal, so as to control the brightness of the light source of the light source module 15;

[0077] The current acquisition module 14 is configured to acquire a second voltage signal from the light source module 15 , process the second voltage signal to obtain a second digital signal, and transmit the second digital signal to the processing module 11 ;

[0078] The processing module 11 is further configured to receive the second digital signal, obtain the operating current of the light source module 15 according to the second digital signal, and adjust the output of the current setting module 12 based on the operating current of the light source module 15 .

[0079] Processing module 11 is the core of the circuit, performing data processing, managing and controlling various modules, and ensuring the normal operation of the circuit. The type, processing capabilities, interface resources, and minimum system components of processing module 11 vary among different electronic devices. Processing module 11 can be an MCU (Microcontroller Unit), a DSP (Digital Signal Processor), a SOC (System-on-Chip Integrated Circuit), an FPGA (Field Programmable Gate Array), a CPU (Central Processing Unit), a PCH (Platform Controller Hub), or an SIO (Super Input / Output).

[0080] The current setting module 12 receives the control signal, communication bus signal and other possible custom signals sent by the processing module 11, and directly / indirectly sets different analog voltage signals to achieve the setting of different input voltage signals for the constant current driving module 13.

[0081] The constant current drive module 13 can be composed of components such as an operational amplifier, a switch tube, a resistor, and a capacitor. The core mechanism is a negative feedback mechanism. The constant current drive module 13 controls the operating current of the light source module 15 to control the brightness of the light source module 15.

[0082] The current acquisition module 14 collects the voltage signal from the light source module 15 and feeds it back to the processing module 11, allowing the processing module 11 to obtain the operating current of the light source module 15 (the current flowing through the light source module 15). Based on the operating current of the light source module 15, the output of the current setting module 12 is adjusted to achieve a closed-loop regulation function. In addition, the processing module 11 obtains the operating current of the light source module 15 and can also implement related overcurrent and short-circuit protection functions. The core component of the current acquisition module 14 can be a current sampling resistor or a Hall effect device, etc., and can be combined with components such as an operational amplifier, a comparator, a resistor, and a capacitor to form a component.

[0083] The light source module 15 can be a single lamp bead or can be composed of multiple lamp beads arranged together. The lamp bead can be an LED (light-emitting diode), an LD (laser diode), a halogen lamp, a fluorescent lamp, or other forms of lamp beads.

[0084] In an embodiment of the present application, a current acquisition module 14 is set to collect the voltage signal of the light source module 15 and report it to the processing module 11, so that the processing module 11 obtains the working current of the light source module 15, and adjusts the output of the current setting module 12 based on the working current of the light source module 15 to achieve closed-loop control. Compared with the open-loop control method in the related technology, the stability of the light source module 15 can be improved.

[0085] In one possible implementation, see Figure 2 , the circuit 1 further includes: a temperature acquisition module 16;

[0086] The temperature acquisition module 16 includes a temperature acquisition submodule 161 and a third signal conversion submodule 162;

[0087] The temperature acquisition submodule 161 is connected to the third signal conversion submodule 162, and the third signal conversion submodule 162 is connected to the processing module 11;

[0088] The temperature acquisition submodule 161 is configured to generate a third voltage signal corresponding to the temperature of the module to be tested, and transmit the third voltage signal to the third signal conversion submodule 162; wherein the module to be tested is any one of the processing module 11, the current setting module 12, the constant current driving module 13, the current acquisition module 14, and the light source module 15;

[0089] The third signal conversion submodule 162 is configured to receive the third voltage signal, convert the third voltage signal into a third digital signal, and transmit the converted signal to the processing module 11;

[0090] The processing module 11 is further configured to receive the third digital signal and obtain the temperature of the module to be measured according to the third digital signal.

[0091] Each module in the light source driver circuit 1 is required to function normally within a certain ambient temperature range. However, temperatures that are too high or too low can cause irreversible damage to the components. The temperature acquisition module 16 collects a voltage signal corresponding to the real-time temperature of the module under test and feeds it back to the processing module 11. The processing module 11 then analyzes and converts the voltage signal into the real-time temperature of the module under test, enabling temperature display, over-temperature protection, under-temperature protection, temperature compensation, and other related functions based on temperature parameters.

[0092] For example, if the module under test is constant current driver module 13, current continuously flows through the MOSFET (a field-effect transistor) in constant current driver module 13. Assuming the current is I1 and the voltage drop of the MOSFET is U1, the heat generated by the MOSFET is P = U1 × I1. If I1 or U1 increases further, the junction temperature of the MOSFET will continue to rise, posing a risk of burnout. Temperature acquisition module 16 collects a voltage signal corresponding to the real-time temperature of the MOSFET and feeds it back to processing module 11. If the temperature detected by processing module 11 exceeds a preset temperature, processing module 11 controls current setting module 12 to shut down constant current driver module 13, thereby protecting the MOSFET.

[0093] The core component of the temperature acquisition module 16 can be an NTC (Negative Temperature Coefficient, negative temperature coefficient thermistor), a PTC (Positive Temperature Coefficient, positive temperature coefficient thermistor), a temperature-sensitive diode, or other types of temperature sensors, etc., and can be combined with an operational amplifier, a comparator, a resistor, a capacitor, and other devices to form a component.

[0094] In one possible implementation, the temperature acquisition submodule 161 may include an NTC, which is a sensor resistor whose resistance decreases as temperature increases. The third signal conversion submodule 162 may be an analog-to-digital converter (ADC). The NTC is placed close to the module to be tested (the module that requires temperature monitoring). At different temperatures, the NTC will exhibit different resistance values. Through a simple voltage divider circuit (see Figure 6 The temperature acquisition submodule 161 may include an NTC 1611 and a fixed resistor 1612. The NTC 1611 and the fixed resistor 1612 form a voltage divider circuit, VCC is a power supply terminal, and GND is a ground. The corresponding relationship between different temperatures and different third voltage signals can be obtained (the corresponding relationship between the resistance value of the NTC and the temperature is known. The change in the resistance value is reflected in the change in the third voltage signal. Therefore, the corresponding relationship between the temperature and the third voltage signal can be obtained). The analog-to-digital converter ADC acquires the third voltage signal on the NTC, converts the third voltage signal into a third digital signal, and then reports it to the processing module 11. The processing module 11 parses and converts it to obtain the real-time temperature of the module to be measured.

[0095] In an embodiment of the present application, a temperature acquisition module 16 is provided to collect a voltage signal corresponding to the real-time temperature of the module to be measured and feed it back to the processing module 11, so that the processing module 11 can analyze and convert the real-time temperature of the module to be measured, thereby realizing temperature display, over-temperature protection, low-temperature protection, temperature compensation and other related functions based on temperature parameters.

[0096] In one possible implementation, see Figure 3 , the current setting module 12 includes a first signal conversion submodule 121 and a switch submodule 122;

[0097] The first signal conversion submodule 121 is connected to the processing module 11 and the switch submodule 122 respectively, and the switch submodule 122 is connected to the constant current driving module 13 and the processing module 11 respectively;

[0098] The first signal conversion submodule 121 is configured to output multiple voltage signals to the switch submodule 122;

[0099] The switch submodule 122 is configured to respond to the control signal and select a first voltage signal corresponding to the control signal from the multiple voltage signals and output the first voltage signal to the constant current driving module 13 .

[0100] The processing module 11 is further configured to send a first digital signal to the first signal conversion submodule 121, wherein the first digital signal represents a voltage value of each voltage signal in the multiple voltage signals;

[0101] The first signal conversion submodule 121 is further configured to receive the first digital signal output by the processing module 11 and set the voltage values ​​of the multi-channel output voltages according to the first digital signal.

[0102] The first signal conversion submodule 121 can be a digital to analog converter (DAC). The digital to analog converter DAC can receive the first digital signal sent by the processing module 11 through its own SPI (Serial Peripheral Interface) interface, convert the first digital signal into multiple voltage signals, and then use its own output channel to output multiple different voltage signals to the switch submodule 122.

[0103] The switch submodule 122 can be an analog switch with multi-channel input and single-channel output. The analog switch can receive the control signal sent by the processing module 11 through its own enable pin, and in response to different control signals, connect its different input pins and output pins, thereby realizing the setting of different input voltage signals for the constant current drive module 13.

[0104] In the embodiment of the present application, the first signal conversion submodule 121 and the switch submodule 122 are used to set different input voltage signals of the constant current driving module 13, and to set and switch multiple bias currents, so that the constant current driving module 13 can realize dimming control of the light source module 15, and the light source module 15 can realize a fast strobe function.

[0105] In one possible implementation, see Figure 4 The constant current driving module 13 includes a comparison submodule 131, a driving submodule 132 and a current sampling submodule 133;

[0106] The comparison submodule 131 is connected to the current setting module 12, the current sampling submodule 133, and the driving submodule 132 respectively. The driving submodule 132 is connected to the light source module 15 and the current sampling submodule 133 respectively. The current sampling submodule 133 is connected to the current acquisition module 14.

[0107] The current acquisition submodule 133 is configured to acquire a second voltage signal from the light source module 15 and transmit the second voltage signal to the comparison submodule 131 and the current acquisition module 14 respectively;

[0108] The comparison submodule 131 is configured to receive the first voltage signal and the second voltage signal, compare the first voltage signal with the second voltage signal, and output a fourth voltage signal to the driving submodule 132;

[0109] The driving submodule 132 is configured to receive the fourth voltage signal and control the operating current of the light source module 15 according to the fourth voltage signal.

[0110] The current sampling module 133 can be a current sampling resistor, which converts the current signal flowing through the light source module 15 into a voltage signal. The current sampling resistor is a resistor used to convert the current signal in the circuit into a voltage signal. When the measured current flows through the resistor, according to Ohm's law, the voltage across the resistor is proportional to the current. By measuring this voltage, the current in the circuit can be indirectly measured.

[0111] The comparison submodule 131 can be an operational amplifier, which receives a first voltage signal through its own non-inverting input terminal and a second voltage signal through its own inverting input terminal (the second voltage signal is a part of the output signal of the operational amplifier), and sends a part of the output signal of the operational amplifier (the fourth voltage signal) back to the inverting input terminal of the operational amplifier, mixes it with the input signal of the non-inverting input terminal, weakens the net input signal of the operational amplifier, and makes the constant current driving module 13 tend to be stable. This process is called negative feedback of the operational amplifier. The stability of the light source module 15 can be improved through the negative feedback characteristic.

[0112] The driving submodule 132 may be a switching tube MOSFET (a field effect transistor), which utilizes the constant current region characteristics of the MOSFET to achieve constant current driving.

[0113] In the embodiment of the present application, the stability of the light source module 15 can be improved by comparing the negative feedback characteristics of the sub-module 131 .

[0114] In one possible implementation, see Figure 5 , the current acquisition module 14 includes a following submodule 141 and a second signal conversion submodule 142;

[0115] The following submodule 141 is connected to the current sampling submodule 133 and the second signal conversion submodule 142 respectively, and the second signal conversion submodule 142 is connected to the processing module 11;

[0116] The following submodule 141 is configured to collect the second voltage signal of the light source module 15 and output a fifth voltage signal following the second voltage signal; wherein the voltage value of the second voltage signal is equal to the voltage value of the fifth voltage signal;

[0117] The second signal conversion submodule 142 is configured to receive the fifth voltage signal, convert the fifth voltage signal into the second digital signal, and transmit the second digital signal to the processing module 11 .

[0118] The follower submodule 141 can be an operational amplifier that can implement a voltage-following function. That is, the operational amplifier is an operational amplifier with a voltage gain of 1. The output voltage directly follows the input voltage, that is, the output voltage is the same as the input voltage, and no amplification or attenuation is provided to the signal. The notable characteristics of this operational amplifier are high input impedance and low output impedance. This can isolate the mutual influence between the front- and rear-stage circuits, thus providing isolation. It can also "filter" the current signal of the light source module 15, receiving only the voltage signal.

[0119] The second signal conversion submodule 142 can be an analog-to-digital converter ADC. The analog-to-digital converter ADC converts the fifth voltage signal output by the follower submodule 141 into a second digital signal and reports it to the processing module 11. The processing module 11 analyzes and converts the operating current of the light source module 15, so that the processing module 11 adjusts the output of the current setting module 12 based on the operating current of the light source module 15, thereby realizing the closed-loop regulation function.

[0120] In the embodiment of the present application, the voltage signal of the light source module 15 is collected and converted by the following submodule 141 and the second signal conversion submodule 142, so that the processing module 11 can analyze and convert the working current of the light source module 15, and then perform PID adjustment (Proportional, proportional; Integral, integral; Derivative; PID adjustment is a regulation method based on the three control modes of Proportional, Integral, and Derivative) on the output of the current setting module 12 based on the working current of the light source module 15, to achieve closed-loop control, so that the working current of the light source module 15 is always stable within a preset range, thereby improving the stability of the light source module 15 and enhancing the light source uniformity of the light source module 15.

[0121] In one possible implementation, see Figure 6 , the processing module 11 includes a field programmable gate array FPGA111; the first signal conversion submodule 121 includes a digital-to-analog converter 1211; the switch submodule 122 includes an analog switch 1221;

[0122] The input pin IO of the FPGA 111 is connected to the control instruction source, the synchronous serial communication interface SPI Master of the FPGA 111 is connected to the SPI Slave interface of the digital-to-analog converter 1211, and the output pin IOn of the FPGA 111 is connected to the enable pin ENn of the analog switch 1221 in a one-to-one correspondence;

[0123] The output pin DACn of the digital-to-analog converter 1211 is connected to the input pin INn of the analog switch 1221 in a one-to-one correspondence, and the output pin OUT of the analog switch 1221 is connected to the constant current driving module 13;

[0124] The FPGA 111 is configured to send a first digital signal to the digital-to-analog converter 1211 via its own SPI Master interface;

[0125] The digital-to-analog converter 1211 is configured to receive the first digital signal through its own SPI Slave interface, set the voltage values ​​of the multiple output voltages according to the first digital signal, and output the multiple voltage signals to the analog switch 1221;

[0126] The FPGA 111 is further configured to obtain a control instruction through its own input pin IO and output a control signal to the analog switch 1221 according to the control instruction;

[0127] The analog switch 1221 is configured to respond to the control signal and select a first voltage signal corresponding to the control signal from the multiple voltage signals and output the first voltage signal to the constant current driving module 13 .

[0128] Compared with MCU or other SOC, FPGA is hardware programmable, and the function of each logic unit is completely fixed. There is no loss such as instruction decoding and execution, access arbitration, etc. of the von Neumann architecture. Therefore, the delay is very small and can generally be controlled within tens of ns (nanoseconds).

[0129] In an example, the control instruction source sends a camera exposure instruction to FPGA111. FPGA111 outputs a control signal to the enable pin EN0 of the analog switch 1221 through its own output pin IO0 according to the camera exposure instruction. When EN0 is enabled, the input pin IN0 and the output pin OUT of the analog switch 1221 are turned on, and the channel corresponding to the input pin IN0 is opened. The first voltage signal of the channel is output to the constant current drive module 13 through the output pin OUT. The brightness of the light source corresponding to the first voltage signal is the maximum, achieving a fill light effect.

[0130] In the embodiment of the present application, the low latency advantage of the FPGA processor is used to achieve rapid linkage between the light source and the signal generator, thereby improving the real-time performance and operating efficiency of the light source system.

[0131] In one possible implementation, see Figure 6The comparison submodule 131 includes a first operational amplifier 1311; the driving submodule 132 includes a switch tube 1321; the current sampling submodule 133 includes a current sampling resistor 1331; the following submodule 141 includes a second operational amplifier 1411 and a feedback resistor 1412; the second signal conversion submodule 142 includes an analog-to-digital converter 1421;

[0132] The non-inverting input terminal + of the first operational amplifier 1311 is connected to the current setting module 12, the inverting input terminal - of the first operational amplifier 1311 is connected to the second terminal of the switch tube 1321 and the first terminal of the current sampling resistor 1331 respectively, and the output terminal of the first operational amplifier 1311 is connected to the control terminal (gate) of the switch tube 1321;

[0133] The first end of the switch tube 1321 is connected to the light source module 15;

[0134] The second end of the current collecting resistor 1331 is grounded to GND;

[0135] The non-inverting input terminal + of the second operational amplifier 1411 is connected to the first end of the current sampling resistor 1331, the inverting input terminal - of the second operational amplifier 1411 is connected to the second end of the feedback resistor 1412, and the output terminal of the second operational amplifier 1411 is connected to the first end of the feedback resistor 1412 and the input pin ADC3 of the analog-to-digital converter 1421 respectively;

[0136] The SPI interface SPI Slave of the analog-to-digital converter 1421 is connected to the processing module 11 .

[0137] The switch tube 1321 can be a MOSFET, and constant current driving is achieved by utilizing the constant current region characteristics of the MOSFET.

[0138] In one possible implementation, see Figure 6 , the circuit 1 further includes a trigger module 17;

[0139] The trigger module 17 is used to connect to a signal generating source, and the processing module 11 is connected to the trigger module 17;

[0140] The trigger module 17 is configured to obtain an unprocessed control instruction, perform functional processing on the unprocessed control instruction to obtain the control instruction, and output the control instruction to the processing module 11 .

[0141] Trigger module 17 receives input signals (unprocessed control instructions) from a signal generator, processes them through relevant functional circuits, and then provides them to processing module 11. Trigger module 17 may have one or more functions including protection, filtering, current limiting, voltage division, and isolation. Trigger module 17 may be constructed from optocouplers and other components, transceivers and other components, or other circuit components.

[0142] In one possible implementation, see Figure 6 , the trigger module 17 includes a high-speed optical coupler 171;

[0143] The input pin LED+ of the high-speed optocoupler 171 is connected to the signal generating source, and the output pin OUT of the high-speed optocoupler 171 is connected to the processing module 11;

[0144] The high-speed optical coupler 171 is used to obtain unprocessed control instructions, isolate the unprocessed control instructions from the processing module 11 to obtain the control instructions, and output the control instructions to the processing module 11 .

[0145] By setting up a high-speed optocoupler 171, the signal of the signal source can be isolated from the signal of the processing module 11, which can effectively improve the anti-interference and protection capabilities of the circuit, and its transmission and conversion delay can be controlled within tens of ns, which can ensure the rapid linkage between the light source and the signal source, and improve the real-time performance and operating efficiency of the light source system.

[0146] In order to help readers better understand the solution of this application, the following technical solution of this application is described through specific examples. Figure 6 Understand.

[0147] The user presets the maximum brightness and bias brightness parameters of the light source on the host computer and sends them to FPGA111 through the Universal Asynchronous Receiver / Transmitter (UART) serial port. The light source brightness adjustment range can be 0-100, and the bias brightness parameter can be 50.

[0148] FPGA111 parses the data sent by the host computer and sets the voltage of each output pin of the digital-to-analog converter 1211 through the SPI Master interface, such as DAC0 is set to 3.3V (corresponding to the maximum brightness of the light source 100), DAC1 is set to 1.65V (corresponding to the brightness of the light source 50), and DAC2 is set to 0V (corresponding to the brightness of the light source 0). When FPGA111 outputs a control signal to the enable pin EN0 of the analog switch 1221 through its own output pin IO0, EN0 is enabled, the input pin IN0 and the output pin OUT of the analog switch 1221 are turned on, and the channel corresponding to the input pin IN0 is turned on. The 3.3V voltage of the channel is output to the constant current drive module 13 through the output pin OUT. At this time, the brightness of the light source is 100; when FPGA111 outputs a control signal to the enable pin EN1 of the analog switch 1221 through its own output pin IO1, EN1 is enabled, and the input pin IN0 of the analog switch 1221 is turned on. 1 and the output pin OUT are turned on, the channel corresponding to the input pin IN1 is turned on, and the 1.65V voltage of the channel is output to the constant current driving module 13 through the output pin OUT. At this time, the brightness of the light source is 50; when the FPGA111 outputs a control signal to the enable pin EN2 of the analog switch 1221 through its own output pin IO2, EN2 is enabled, the input pin IN2 and the output pin OUT of the analog switch 1221 are turned on, the channel corresponding to the input pin IN2 is turned on, and the 0V voltage of the channel is output to the constant current driving module 13 through the output pin OUT. At this time, the brightness of the light source is 0.

[0149] The signal source can be a high-speed linear array camera. The image sensor of the high-speed linear array camera can capture images at a frequency of tens of Khz (hertz) to 100 Khz, and load the exposure synchronization signal to the output interface DO. The exposure synchronization signal (unprocessed control instruction) is transmitted to the input pin (light-emitting diode anode) LED+ of the high-speed optocoupler 171 through the output interface DO. The level of the output pin OUT of the high-speed optocoupler 171 is flipped following the camera exposure synchronization signal and transmitted to the input pin IO (control instruction) of the FPGA111.

[0150] FPGA111 receives the control command output by high-speed optocoupler 171 and uses the signal frequency and duty ratio of the control command to control the enable pins EN0 and EN1 of analog switch 1221. During camera exposure, EN0 is enabled, and the connection between input pin IN0 and output pin OUT of analog switch 1221 is connected. The input voltage of constant current driver module 13 is 3.3V, corresponding to a light source brightness of 100, achieving a fill light effect. After the camera exposure is completed, EN0 is disabled and EN1 is enabled. The connection between input pin IN1 and output pin OUT of analog switch 1221 is connected, and the input voltage of constant current driver module 13 is 1.65V, corresponding to a light source brightness of 50. This achieves a 25% reduction in light source power consumption and heat generation within a cycle, effectively extending the life of light source module 15.

[0151] According to the different voltage signals loaded to the output pin OUT of the analog switch 1221, the first operational amplifier 1311 and the switch tube 1321 realize the change control of the current and brightness of the light source module 15, and the control relationship conforms to I=VDAC / Rsense, where I is the current value of the operating current of the light source module 15, VDAC is the voltage value of the voltage signal (first voltage signal) output by the output pin OUT of the analog switch 1221, and Rsense is the resistance value of the current sampling resistor 1331.

[0152] The voltage across the current sampling resistor 1331 (the second voltage signal) is fed back to the non-inverting input terminal + of the second operational amplifier 1411. The second operational amplifier 1411 follows or amplifies the second voltage signal before inputting it to the analog-to-digital converter 1421 (the fifth voltage signal). The analog-to-digital converter 1421 converts the fifth voltage signal into a second digital signal and reports it to the FPGA 111 via the SPI interface SPISlave, implementing closed-loop control. The relationship between the operating current of the light source module 15 and the fifth voltage signal obtained by the input pin ADC3 of the analog-to-digital converter 1421 conforms to the equation I = VADC3 / Rsense × K, where K is the gain factor of the second operational amplifier 1411 and VADC3 is the voltage value of the fifth voltage signal. Simultaneously, the voltage across the current sampling resistor 1331 (the second voltage signal) is also fed back to the inverting input terminal - of the first operational amplifier 1311. This large-loop-within-a-small-loop control scheme effectively improves the stability of the light source module 15 and enhances the reliability of the light source driver circuit 1.

[0153] In one possible implementation, see Figure 6The analog-to-digital converter of the third signal conversion submodule 162 can be analog-to-digital converter 1421. That is, the temperature acquisition module 16 and the current acquisition module 14 can share a single analog-to-digital converter. Analog-to-digital converter 1421 acquires the third voltage signal from the NTC 1611 via input pin ADC0, converts the third voltage signal into a third digital signal, and reports it to FPGA 111 via the SPI Slave interface (SPI Slave). (The FPGA 111 receives the signal via its SPI Master interface). FPGA 111 then analyzes and calculates the real-time temperature of the module under test. The relationship between voltage and temperature depends on the temperature coefficient of the NTC 1611 and the selection of the voltage divider resistor. This allows FPGA 111 to obtain the temperature of the module under test in real time and implement temperature-related functions based on user software logic.

[0154] The present application also provides a light source system 2, see Figure 7 , the light source system 2 includes a signal generator 21, a power supply circuit 22 and the light source driving circuit 1 described in any one of the above embodiments;

[0155] The signal generator 21 is connected to the light source driving circuit 1, and the power supply circuit 22 is connected to the light source driving circuit 1;

[0156] The signal generator 21 is used to generate an unprocessed control instruction and send the unprocessed control instruction to the light source driving circuit 1;

[0157] The power supply circuit 22 is used to provide power to each module in the light source driving circuit 1 .

[0158] The power supply circuit 22 may be a DCDC (Direct Current to Direct Current) power module or an ACDC (Alternating Current to Direct Current) power module, which is not specifically limited in this application.

[0159] The signal generating source 21 may be a high-speed linear array camera, various sensors, or other signal generating devices, which is not specifically limited in this application.

[0160] The light source driving circuit 1 provided in the present application has the characteristics of good constant current driving uniformity, high reliability, high stability, high real-time performance, low latency, and fast strobe, and can be widely used in various electronic devices, such as machine vision systems, lighting light source driver systems, and other types of light source systems.

[0161] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0162] Each embodiment in this specification is described in a related manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiment is generally similar to the method embodiment, so the description is relatively simple. For related parts, refer to the description of the method embodiment.

[0163] The above description is only a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application are included in the scope of protection of the present application.

Claims

1. A light source driving circuit, characterized in that: The circuit comprises: Processing module, current setting module, constant current driving module, current acquisition module and light source module; The processing module is connected to the current setting module and the current acquisition module respectively, the current setting module is connected to the constant current driving module, and the constant current driving module is connected to the current acquisition module and the light source module respectively; The processing module is configured to obtain a control instruction and output a control signal to the current setting module according to the control instruction; The current setting module is configured to receive the control signal and select a first voltage signal corresponding to the control signal from multiple voltage signals and output the signal to the constant current driving module; The constant current driving module is configured to receive the first voltage signal and control the operating current of the light source module according to the first voltage signal, so as to control the brightness of the light source of the light source module; The current acquisition module is configured to acquire a second voltage signal from the light source module, process the second voltage signal to obtain a second digital signal, and transmit the second digital signal to the processing module; The processing module is further configured to receive the second digital signal, obtain an operating current of the light source module according to the second digital signal, and adjust the output of the current setting module based on the operating current of the light source module.

2. The circuit according to claim 1, wherein: The circuit further includes: a temperature acquisition module; The temperature acquisition module includes a temperature acquisition submodule and a third signal conversion submodule; The temperature acquisition submodule is connected to the third signal conversion submodule, and the third signal conversion submodule is connected to the processing module; The temperature acquisition submodule is configured to generate a third voltage signal corresponding to the temperature of the module to be measured, and transmit the third voltage signal to the third signal conversion submodule; wherein the module to be measured is any one of the processing module, the current setting module, the constant current driving module, the current acquisition module, and the light source module; The third signal conversion submodule is configured to receive the third voltage signal, convert the third voltage signal into a third digital signal, and transmit the converted signal to the processing module; The processing module is further configured to receive the third digital signal and obtain the temperature of the module to be tested according to the third digital signal.

3. The circuit according to claim 1, wherein: The current setting module includes a first signal conversion submodule and a switch submodule; The first signal conversion submodule is connected to the processing module and the switch submodule respectively, and the switch submodule is connected to the constant current driving module and the processing module respectively; The first signal conversion submodule is configured to output multiple voltage signals to the switch submodule; The switch submodule is configured to respond to the control signal and select a first voltage signal corresponding to the control signal from the multiple voltage signals and output it to the constant current driving module.

4. The circuit according to claim 3, characterized in that The processing module is further configured to send a first digital signal to the first signal conversion submodule, wherein the first digital signal represents a voltage value of each voltage signal in the multiple voltage signals; The first signal conversion submodule is configured to receive the first digital signal output by the processing module and set the voltage values ​​of the multiple output voltages according to the first digital signal.

5. The circuit according to claim 1, wherein: The constant current driving module includes a comparison submodule, a driving submodule and a current sampling submodule; The comparison submodule is connected to the current setting module, the current sampling submodule, and the driving submodule respectively; the driving submodule is connected to the light source module and the current sampling submodule respectively; and the current sampling submodule is connected to the current acquisition module; The current acquisition submodule is configured to acquire a second voltage signal from the light source module and transmit the second voltage signal to the comparison submodule and the current acquisition module respectively; The comparison submodule is configured to receive the first voltage signal and the second voltage signal, compare the first voltage signal with the second voltage signal, and output a fourth voltage signal to the driving submodule; The driving submodule is configured to receive the fourth voltage signal and control the operating current of the light source module according to the fourth voltage signal.

6. The circuit according to claim 5, characterized in that The current acquisition module includes a following submodule and a second signal conversion submodule; The following submodule is connected to the current sampling submodule and the second signal conversion submodule respectively, and the second signal conversion submodule is connected to the processing module; The following submodule is configured to collect the second voltage signal of the light source module and output a fifth voltage signal following the second voltage signal; wherein the voltage value of the second voltage signal is equal to the voltage value of the fifth voltage signal; The second signal conversion submodule is configured to receive the fifth voltage signal, convert the fifth voltage signal into the second digital signal, and transmit the second digital signal to the processing module.

7. The circuit according to claim 4, characterized in that The processing module includes a field programmable gate array (FPGA); the first signal conversion submodule includes a digital-to-analog converter; the switch submodule includes an analog switch; The input pins of the FPGA are connected to a control instruction source, the synchronous serial communication interface SPI interface of the FPGA is connected to the SPI interface of the digital-to-analog converter, and the output pins of the FPGA are connected to the enable pins of the analog switch in a one-to-one correspondence; The output pins of the digital-to-analog converter are connected to the input pins of the analog switch in a one-to-one correspondence, and the output pins of the analog switch are connected to the constant current drive module; The FPGA is configured to send a first digital signal to the digital-to-analog converter via its own SPI interface; The digital-to-analog converter is configured to receive the first digital signal through its own SPI interface, set the voltage values ​​of the multiple output voltages according to the first digital signal, and output multiple voltage signals to the analog switch; The FPGA is further configured to obtain a control instruction through its own input pins and output a control signal to the analog switch according to the control instruction; The analog switch is used to respond to the control signal and select a first voltage signal corresponding to the control signal from the multiple voltage signals and output it to the constant current driving module.

8. The circuit according to claim 6, characterized in that The comparison submodule includes a first operational amplifier; the driving submodule includes a switch tube; the current sampling submodule includes a current sampling resistor; the follower submodule includes a second operational amplifier and a feedback resistor; the second signal conversion submodule includes an analog-to-digital converter; The non-inverting input terminal of the first operational amplifier is connected to the current setting module, the inverting input terminal of the first operational amplifier is connected to the second terminal of the switching tube and the first terminal of the current sampling resistor respectively, and the output terminal of the first operational amplifier is connected to the control terminal of the switching tube; The first end of the switch tube is connected to the light source module; The second end of the current collecting resistor is grounded; The non-inverting input terminal of the second operational amplifier is connected to the first end of the current sampling resistor, the inverting input terminal of the second operational amplifier is connected to the second end of the feedback resistor, and the output terminal of the second operational amplifier is connected to the first end of the feedback resistor and the input pin of the analog-to-digital converter respectively; The SPI interface of the analog-to-digital converter is connected to the processing module.

9. The circuit according to claim 1, wherein: The circuit further includes a trigger module; The trigger module is used to connect to a signal generating source, and the processing module is connected to the trigger module; The trigger module is used to obtain an unprocessed control instruction, perform functional processing on the unprocessed control instruction to obtain the control instruction, and output the control instruction to the processing module.

10. The circuit according to claim 9, characterized in that The trigger module includes a high-speed optocoupler; The input pin of the high-speed optocoupler is connected to the signal generating source, and the output pin of the high-speed optocoupler is connected to the processing module; The high-speed optocoupler is used to obtain unprocessed control instructions, isolate the unprocessed control instructions from the processing module to obtain the control instructions, and output the control instructions to the processing module.

11. A light source system, characterized in that: The light source system includes a signal generating source, a power supply circuit and the light source driving circuit according to any one of claims 1 to 10; The signal generating source is connected to the light source driving circuit, and the power supply circuit is connected to the light source driving circuit; The signal generating source is used to generate an unprocessed control instruction and send the unprocessed control instruction to the light source driving circuit; The power supply circuit is used to provide power to each module in the light source driving circuit.

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