Light source driving circuit and light source system

Abstract

The embodiment of the invention provides a light source driving circuit and a light source system. The light source driving circuit comprises 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, selects a first voltage signal corresponding to the control signal from the multiple paths of voltage signals and outputs the first voltage signal to the constant current driving module; the constant-current driving module receives the first voltage signal and controls the working current of the light source module according to the first voltage signal so as to control the light source brightness of the light source module; the current acquisition module acquires a 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 working current of the light source module according to the second digital signal, and adjusts the output of the current setting module based on the working 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] In current machine vision systems, constant current driving solutions are usually used to drive light source illumination. Generally, the output current value remains unchanged. In certain specific occasions, such as 2.5D (a transitional form between 2D and 3D) light source systems, PL (Photoluminescence) detection systems, etc., the pulse width, output current, flashing frequency and other parameters of the constant current driving need to be adjustable in real time, which can further improve the precision and compatibility of the light source. However, the above constant current driving solutions usually adopt the control method of input controlling output, resulting in low stability of the light source. 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 solution is 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 used 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 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;

[0009] The constant current driving module is used to receive the first voltage signal and control the working 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;

[0010] The current acquisition module is used to acquire 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;

[0011] The processing module is further configured 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.

[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 used 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; wherein the module to be tested 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 used to receive the third voltage signal, convert the third voltage signal into a third digital signal and transmit it to the processing module;

[0017] The processing module is further used 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 manner, 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 used to output multiple voltage signals to the switch submodule;

[0021] The switch submodule 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.

[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 used 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 manner, 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 collecting submodule and the driving submodule respectively, the driving submodule is connected to the light source module and the current collecting submodule respectively, and the current collecting submodule is connected to the current collecting module;

[0027] The current acquisition submodule is used to acquire the second voltage signal of 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 used 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 used 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 manner, 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 used 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 used 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; the switch submodule includes an analog switch;

[0035] The input pin of the FPGA is 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 pin of the FPGA is connected to the enable pin 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 driving module;

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

[0038] The digital-to-analog converter is used 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 used to obtain a control instruction through its own input pin, 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 a 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 following submodule includes a second operational amplifier and a feedback resistor; 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 reverse input terminal of the first operational amplifier is respectively connected to the second terminal of the switch tube and the first terminal of the current sampling resistor, and the output terminal of the first operational amplifier is connected to the control terminal of the switch 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 respectively connected to the first end of the feedback resistor and the input pin of the analog-to-digital converter;

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

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

[0048] The trigger module is used to connect to a signal 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 optical coupler;

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

[0052] The high-speed optical coupler 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, the light source system comprising a signal generating source, a power supply circuit, and any one of the light source driving circuits described in the first aspect 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] A light source driving circuit and a light source system provided in an embodiment of the present application, the light source driving circuit comprises: 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 a plurality of 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 working current of the light source module according to the first voltage signal to realize the 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 working current of the light source module according to the second digital signal, and adjust the output of the current setting module based on the working 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, and the output of the current setting module is adjusted based on the working current of the light source module to achieve closed-loop control, thereby improving the stability of the light source.

[0059] Of course, implementing any product or method of the present application does not necessarily require achieving all of the advantages described above at the same time. 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

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

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

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

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

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

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

[0067] Figure 7 A schematic diagram of the structure 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 the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field based on the present application belong to the scope of protection of the present application.

[0069] In machine vision systems, light sources need to cooperate with cameras to take photos and images of objects from multiple directions and angles. The commonly used cameras in machine vision systems are high-speed line scan cameras. In order to detect different defect features of different objects, it is often necessary to image objects from different physical positions and angles and with different light source brightness to obtain different types of defect features, which is convenient for image recognition and processing. Among them, the brightness of the light source will directly affect the quality of the image, and then affect the extraction of feature values. Therefore, the control of the light source plays a vital role in the machine vision system.

[0070] In current machine vision systems, constant current driving solutions are usually used to drive light source illumination. Generally, the output current value remains unchanged. In certain specific occasions, such as 2.5D (a transitional form between 2D and 3D) light source systems, PL (Photoluminescence) detection systems, etc., the pulse width, output current, flicker frequency and other parameters of the constant current driving need to be adjustable in real time, which can further improve the precision and compatibility of the light source. However, the above constant current driving solutions usually adopt the control method of input controlling output, lacking a feedback mechanism to adjust the light source current in real time, resulting in low stability of the light source.

[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 first structural diagram of a light source driving circuit 1 provided in an embodiment of the present application, the circuit 1 comprises: 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 used 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 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 13;

[0076] The constant current driving module 13 is used to receive the first voltage signal and control the working current of the light source module 15 according to the first voltage signal to achieve control of the light source brightness of the light source module 15;

[0077] The current acquisition module 14 is used to acquire the second voltage signal of the light source module 15, obtain a second digital signal after processing the second voltage 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] The processing module 11 is the core of the circuit, and performs functions such as data processing, management and control of each module, and ensures the normal operation of the circuit. In different electronic devices, the type, processing capability, interface resources, and components of the minimum system of the processing module 11 are also different. The processing module 11 can be an MCU (Microcontroller Unit), a DSP (Digital Signal Processor), a SOC (System-level Integrated Circuit), an FPGA (Field Programmable Gate Array), a CPU (Central Processing Unit), a PCH (Platform Controller Hub), or an SIO (Super Input / Output), etc.

[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 driving module 13 can be composed of operational amplifiers, switch tubes, resistors, capacitors and other devices, and the core mechanism is a negative feedback mechanism. The constant current driving module 13 is used to control the working current of the light source module 15, so as to control the light source brightness of the light source module 15.

[0082] The current acquisition module 14 acquires the voltage signal of the light source module 15 and feeds it back to the processing module 11, so that the processing module 11 obtains the working current of the light source module 15 (the current flowing through 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 realize the closed-loop regulation function. In addition, the processing module 11 obtains the working current of the light source module 15, and can also realize the related overcurrent and short-circuit protection functions. The core component of the current acquisition module 14 can be a current collection resistor, or a Hall device, etc., which can be combined with operational amplifiers, comparators, resistors, capacitors and other devices to realize the composition.

[0083] The light source module 15 may be a single lamp bead or may be composed of a plurality of lamp beads arranged in an arrangement. The lamp bead may 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 provided 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 implement closed-loop control. Compared with the open-loop control method in the related art, 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 used 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 used to receive the third voltage signal, convert the third voltage signal into a third digital signal, and transmit the third digital 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 tested according to the third digital signal.

[0091] Each module in the light source driving circuit 1 is required to work normally within a certain ambient temperature range, but too high or too low temperature will cause irreversible damage to the device. The temperature acquisition module 16 can collect the voltage signal corresponding to the real-time temperature of the module to be tested, and feed it back to the processing module 11, which analyzes and converts the real-time temperature of the module to be tested to realize temperature display, over-temperature protection, low-temperature protection, temperature compensation and other related functions based on temperature parameters.

[0092] Taking the module to be tested as the constant current drive module 13 as an example, the current continuously flows through the switch tube MOSFET (a field effect transistor) in the constant current drive module 13. Assuming that the current is I1 and the voltage drop of the switch tube MOSFET is U1, the heat generation power of the switch tube MOSFET is P=U1×I1. If I1 or U1 increases further, the junction temperature of the switch tube MOSFET will continue to rise, causing the risk of burning. The temperature acquisition module 16 acquires the voltage signal corresponding to the real-time temperature of the switch tube MOSFET and feeds it back to the processing module 11. If the temperature obtained by the processing module 11 exceeds the preset temperature, the processing module 11 will turn off the constant current drive module 13 by controlling the current setting module 12, thereby protecting the switch tube MOSFET.

[0093] The core device of the temperature acquisition module 16 may 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 may be combined with an operational amplifier, a comparator, a resistor, a capacitor, and other devices to realize the composition.

[0094] In a possible implementation, the temperature acquisition submodule 161 may include an NTC, which is a sensor resistor whose resistance decreases as the 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 needs temperature monitoring). At different temperatures, the NTC will present 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, wherein the NTC 1611 and the fixed resistor 1612 form a voltage divider circuit, wherein VCC is a power supply terminal and GND is a ground) and 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, and the change of the resistance value is reflected in the change of the third voltage signal, so the corresponding relationship between the temperature and the third voltage signal can be obtained), and 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 reports it to the processing module 11, and the processing module 11 parses and converts the real-time temperature of the module to be tested.

[0095] In the 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 tested 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 tested, 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 used to output multiple voltage signals to the switch submodule 122;

[0099] The switch submodule 122 is used for selecting a first voltage signal corresponding to the control signal from the multiple voltage signals in response to the control signal and outputting 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 used to receive the first digital signal output by the processing module 11, and set the voltage values ​​of the multiple 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, through the first signal conversion submodule 121 and the switch submodule 122, different input voltage signals of the constant current driving module 13 are set, and multiple bias currents are set and switched, 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 respectively connected to the current setting module 12, the current collecting submodule 133, and the driving submodule 132; the driving submodule 132 is respectively connected to the light source module 15 and the current collecting submodule 133; and the current collecting submodule 133 is connected to the current collecting module 14;

[0107] The current acquisition submodule 133 is used to acquire the second voltage signal of 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 used for receiving the first voltage signal and the second voltage signal, comparing the first voltage signal with the second voltage signal, and outputting a fourth voltage signal to the driving submodule 132;

[0109] The driving submodule 132 is used 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 submodule 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 the first voltage signal through its own non-inverting input terminal, receives the second voltage signal through its own reverse input terminal (the second voltage signal is a part of the output signal of the operational amplifier), 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 characteristics.

[0112] The driving submodule 132 may be a switch tube MOSFET (a field effect transistor), and constant current driving is achieved by utilizing the constant current region characteristics of the MOSFET.

[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 submodule 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 used 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 used 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 realize a voltage following function, that is, the operational amplifier is an operational amplifier with a voltage gain of 1, and 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 for the signal. The notable feature of the operational amplifier is that the input impedance is high and the output impedance is low, which can isolate the mutual influence between the front and rear stage circuits, play an isolation role, and can also "filter" out the current signal of the light source module 15 and only receive 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 parses and converts the working 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 working current of the light source module 15, thereby realizing the function of closed-loop regulation.

[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 analyzes and converts the working current of the light source module 15, and then performs PID adjustment (Proportional, proportional; Integral, integral; Derivative; PID adjustment is a regulation method based on three control modes: Proportional, Integral, 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 improving 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 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 used to send a first digital signal to the digital-to-analog converter 1211 through its own SPI interface SPI Master;

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

[0126] The FPGA 111 is further used 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 used for selecting a first voltage signal corresponding to the control signal from the multiple voltage signals in response to the control signal and outputting 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 von Neumann architecture instruction decoding and execution, access arbitration, etc. 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, thereby 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 source, thereby improving the real-time performance and operating efficiency of the light source system.

[0131] In one possible implementation, see Figure 6, the 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 reverse input terminal - of the first operational amplifier 1311 is respectively connected to the second end of the switch tube 1321 and the first end of the current sampling resistor 1331, 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 respectively connected to the first end of the feedback resistor 1412 and the input pin ADC3 of the analog-to-digital converter 1421;

[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 also 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 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 11.

[0141] The trigger module 17 receives the input signal (unprocessed control instruction) provided by the signal source, and provides it to the processing module 11 after being processed by the relevant functional circuit. The trigger module 17 can have one or more functions of protection, filtering, current limiting, voltage division and isolation, and the trigger module 17 can be composed of an optical coupler and other devices, a transceiver and other devices, or other component circuits.

[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 optical coupler 171 is connected to the signal source, and the output pin OUT of the high-speed optical coupler 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 a high-speed optical coupler 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 enable readers to better understand the solution of the present application, the technical solution of the present application is described below by using specific examples. Figure 6 To 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 interface SPI Master, 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 output pin OUT are turned on, the channel corresponding to 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 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 output pin OUT of the analog switch 1221 are turned on, the channel corresponding to 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 may be a high-speed linear array camera. The image sensor of the high-speed linear array camera may 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 instruction output by the high-speed optocoupler 171, and uses the signal frequency and duty ratio of the control instruction to control the enable pins EN0 and EN1 of the analog switch 1221. When the camera is exposed, EN0 is enabled, the input pin IN0 and the output pin OUT of the analog switch 1221 are connected, the input voltage of the constant current drive module 13 is 3.3V, and the corresponding light source brightness is 100, achieving a fill light effect; after the camera exposure is completed, EN0 is disabled, EN1 is enabled, the input pin IN1 and the output pin OUT of the analog switch 1221 are connected, the input voltage of the constant current drive module 13 is 1.65V, and the corresponding light source brightness is 50, achieving a 25% reduction in light source power consumption and heat generation within a cycle, effectively extending the life of the 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, wherein I is the current value of the working 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 (second voltage signal) across the current collecting resistor 1331 is fed back to the in-phase input terminal + of the second operational amplifier 1411. The second operational amplifier 1411 follows or amplifies the second voltage signal and then inputs it to the analog-to-digital converter 1421 (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 through the SPI interface SPISlave to achieve closed-loop control. The relationship between the working 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 I=VADC3 / Rsense×K, where K is the gain coefficient of the second operational amplifier 1411 and VADC3 is the voltage value of the fifth voltage signal. At the same time, the voltage (second voltage signal) across the current collecting resistor 1331 is also fed back to the inverting input terminal - of the first operational amplifier 1311. This large-loop-in-small-loop control mode can effectively improve the stability of the light source module 15 and the reliability of the light source driving circuit 1.

[0153] In one possible implementation, see Figure 6, the analog-to-digital converter of the third signal conversion submodule 162 can be an analog-to-digital converter 1421, that is, the temperature acquisition module 16 and the current acquisition module 14 can share an analog-to-digital converter. The analog-to-digital converter 1421 collects the third voltage signal on the NTC1611 through the input pin ADC0, converts the third voltage signal into a third digital signal and reports it to the FPGA111 through the SPI interface SPI Slave (the SPI interface SPI Master' of the FPGA111 receives it), and the FPGA111 parses and converts the real-time temperature of the module to be tested. The corresponding relationship between voltage and temperature is related to the temperature coefficient of the NTC1611 and the selection of the voltage divider resistor. In this way, the FPGA111 can obtain the temperature of the module to be tested in real time and implement temperature-related functions according to the 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 generating source 21, a power supply circuit 22 and the light source driving circuit 1 described in any one of the above embodiments;

[0155] The signal generating source 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 generating source 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 the present application.

[0159] The signal source 21 may be a high-speed linear array camera, various sensors, or other signal generating devices, which is not specifically limited in the present 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, fast strobe, etc., and can be widely used in various electronic devices, such as machine vision systems, lighting source driver systems and other types of light source systems.

[0161] It should be noted that, in this article, relational terms such as first and second, etc. are only used 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. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0162] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial 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 protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope 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 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 working 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 acquire a second voltage signal from 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 further configured 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.

2. The circuit according to claim 1, characterized in that The circuit also 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 used 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; wherein the module to be tested 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 used to receive the third voltage signal, convert the third voltage signal into a third digital signal and transmit it to the processing module; The processing module is further used 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, characterized in that 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 used to output multiple voltage signals to the switch submodule; The switch submodule 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.

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 used 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, characterized in that 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 collecting submodule and the driving submodule respectively, the driving submodule is connected to the light source module and the current collecting submodule respectively, and the current collecting submodule is connected to the current collecting module; The current acquisition submodule is used to acquire the second voltage signal of the light source module, and transmit the second voltage signal to the comparison submodule and the current acquisition module respectively; The comparison submodule is used 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 used 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 used 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 used 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 pin of the FPGA is 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 pin of the FPGA is connected to the enable pin 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 driving module; The FPGA is used to send a first digital signal to the digital-to-analog converter through its own SPI interface; The digital-to-analog converter is used 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 used to obtain a control instruction through its own input pin, 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 following 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 reverse input terminal of the first operational amplifier is respectively connected to the second terminal of the switch tube and the first terminal of the current sampling resistor, and the output terminal of the first operational amplifier is connected to the control terminal of the switch 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 respectively connected to the first end of the feedback resistor and the input pin of the analog-to-digital converter; The SPI interface of the analog-to-digital converter is connected to the processing module.

9. The circuit according to claim 1, characterized in that The circuit also includes a trigger module; The trigger module is used to connect to a signal 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 optical coupler; The input pin of the high-speed optical coupler is connected to the signal generating source, and the output pin of the high-speed optical coupler is connected to the processing module; The high-speed optical coupler 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 comprises a signal generating source, a power supply circuit and a light source driving circuit as described in any one of claims 1 to 10 above; 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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