An LED light source control system and method

Abstract

This application discloses an LED light source control system and method, relating to the field of light source control. In this control system, a polarizer, an analyzer, a beam shaping assembly, and a beam splitter are sequentially arranged on the output light path of the LED light source; a monitoring light sensor is arranged on the reflected light path of the beam splitter; a gain control module is electrically connected to the monitoring light sensor, the analyzer, and the LED light source; the polarizer converts the unpolarized light emitted by the LED light source into linearly polarized light; the analyzer modulates the linearly polarized light; the beam shaping assembly shapes the modulated light; the beam splitter splits the shaped beam into transmitted working light and reflected sampling light; when the light intensity signal of the sampling light collected in real time by the monitoring light sensor is lower than a set light intensity threshold, the gain control module controls the increase of the driving current of the LED light source or adjusts the rotation angle of the analyzer to dynamically compensate for the light intensity of the working light. This application can achieve high-precision and high-stability light source output.

Description

Technical Field

[0001] This application relates to the field of light source control, and in particular to an LED light source control system and method. Background Technology

[0002] High-brightness LED light sources have been widely used in machine vision, medical devices, and precision optical measurement due to their advantages such as high luminous efficiency, long lifespan, and environmental friendliness. However, high-brightness LEDs are prone to thermal decay and aging when operating for extended periods or when the ambient temperature changes, leading to fluctuations in output light intensity.

[0003] Currently, most power supply control methods employ simple current negative feedback, lacking direct monitoring of the actual output optical path status. Furthermore, in scenarios requiring significant adjustments or stable high brightness, simple current adjustment can easily lead to spectral drift or response hysteresis. Therefore, achieving high-precision and high-stability light source output has become an urgent problem to be solved. Summary of the Invention

[0004] The purpose of this application is to provide an LED light source control system and method that can achieve high-precision and high-stability light source output.

[0005] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides an LED light source control system, comprising: a polarizer, an analyzer, a beam shaping assembly, a beam splitter, a monitoring light sensor, and a gain control module; the polarizer, the analyzer, the beam shaping assembly, and the beam splitter are sequentially arranged on the outgoing light path of the LED light source; the monitoring light sensor is arranged on the reflected light path of the beam splitter; the gain control module is electrically connected to the monitoring light sensor, the analyzer, and the LED light source respectively; The LED light source is used to emit unpolarized light; the polarizer is used to convert the unpolarized light into linearly polarized light; the analyzer is used to modulate the linearly polarized light to obtain modulated light; the beam shaping component is used to shape the modulated light to obtain a shaped beam; the beam splitter is used to split the shaped beam into transmitted working light and reflected sampling light according to a set splitting ratio; the monitoring light sensor is used to collect the light intensity signal of the sampling light in real time; the gain control module is used to control the driving current of the LED light source to increase or adjust the rotation angle of the analyzer when the light intensity signal is lower than a set light intensity threshold, so as to perform dynamic gain compensation for the light intensity of the working light.

[0006] In one embodiment, the beam shaping assembly includes a lens and an aperture; The lens is used to converge and increase the intensity of the modulated light to obtain a processed beam; the aperture is used to limit the aperture of the processed beam, filter out stray light from the lens edge, and obtain a shaped beam.

[0007] In one embodiment, the LED light source control system further includes a stepper motor; the gain control module is electrically connected to the analyzer via the stepper motor.

[0008] In one embodiment, the lens is a Fresnel lens.

[0009] In one embodiment, the set splitting ratio is 95:5, wherein 95% of the light is working light and 5% of the light is sampling light.

[0010] In one embodiment, the monitoring optical sensor is a silicon photodiode.

[0011] In one embodiment, the aperture of the aperture is 80% of the effective light-transmitting aperture.

[0012] In one embodiment, the gain control module reads the light intensity signal of the sampled light at a set sampling frequency.

[0013] In one embodiment, the center wavelength of the LED light source is 550 nm.

[0014] Secondly, this application provides an LED light source control method, which is applied to the aforementioned LED light source control system. The LED light source control method includes: The light intensity signal of the sampling light collected in real time by the monitoring light sensor is obtained; the sampling light is the unpolarized light emitted by the LED light source, which passes through the polarizer, analyzer, beam shaping component and beam splitter in sequence, and is reflected by the beam splitter; the light transmitted and output by the beam splitter is the working light. When the light intensity signal is lower than the set light intensity threshold, the driving current of the LED light source is increased or the rotation angle of the analyzer is adjusted to dynamically compensate the light intensity of the working light.

[0015] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides an LED light source control system and method. By introducing a combination of a polarizer and an analyzer for optical gain modulation, it achieves the ability to fine-tune the light intensity without significantly changing the LED light source's operating current, effectively avoiding spectral shifts caused by sudden current changes. The beam splitter and monitoring optical sensor are located at the end of the optical path, enabling them to most accurately reflect the state of the final output beam. The inclusion of a gain control module enhances the system's anti-interference capability and improves its long-term operational stability. This application achieves high-precision and high-stability light source output. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of an LED light source control system provided in an embodiment of this application.

[0018] Figure reference numerals: LED light source—1; polarizer—2; analyzer—3; lens—4; aperture—5; beam splitter—6; monitoring light sensor—7; working light—8; gain control module—9; communication and control circuit—10; stepper motor—11. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] Currently, there is an urgent need for an LED light source system that can be directly modulated and monitored in the optical path and has a highly stable gain compensation mechanism. To address the problems of fluctuations in output light intensity with temperature and time in existing high-brightness LED light sources and the limited modulation methods, this application provides an LED light source control system and method that enables stable monitoring of gain-type high-brightness LED light sources. This application achieves optical gain modulation by introducing a combination of a polarizer and an analyzer, and combines a beam splitter and a monitoring optical sensor to form a real-time closed-loop feedback, thus realizing high-precision and high-stability light source output.

[0021] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] In one exemplary embodiment, such as Figure 1As shown, an LED light source control system is provided, including: a polarizer 2, an analyzer 3, a beam shaping component, a beam splitter 6, a monitoring light sensor 7, and a gain control module 9; the polarizer 2, the analyzer 3, the beam shaping component, and the beam splitter 6 are sequentially arranged on the output light path of the LED light source 1; the monitoring light sensor 7 is arranged on the reflected light path of the beam splitter 6; the gain control module 9 is electrically connected to the monitoring light sensor 7, the analyzer 3, and the LED light source 1 via a communication and control line 10.

[0023] The LED light source 1 is used to emit unpolarized light; the polarizer 2 is used to convert the unpolarized light into linearly polarized light; the analyzer 3 is used to modulate the linearly polarized light to obtain modulated light; the beam shaping component is used to shape the modulated light to obtain a shaped beam; the beam splitter 6 is used to split the shaped beam into a transmitted working beam 8 and a reflected sampling beam according to a set splitting ratio; the working beam 8 is the main output beam; the monitoring light sensor 7 is used to collect the light intensity signal of the sampling light in real time; the gain control module 9 is used to control the driving current of the LED light source 1 to increase or adjust the rotation angle of the analyzer 3 when the light intensity signal is lower than a set light intensity threshold, so as to perform dynamic gain compensation for the light intensity of the main output working beam 8.

[0024] In another exemplary embodiment of this application, such as Figure 1 As shown, the beam shaping assembly includes a lens 4 and an aperture 5; the lens 4 is used to converge and increase the intensity of the modulated light to obtain a processed beam; the aperture 5 is used to limit the aperture of the processed beam and filter out stray light from the edge of the lens 4 to obtain a shaped beam.

[0025] In another exemplary embodiment of this application, such as Figure 1 As shown, the LED light source control system further includes: a stepper motor 11; the gain control module 9 is electrically connected to the analyzer 3 through the stepper motor 11.

[0026] In another exemplary embodiment of this application, the lens 4 may be a Fresnel lens.

[0027] In another exemplary embodiment of this application, a beam splitter prism 6 with different splitting ratios is selected according to the actual situation. For example, the set splitting ratio can be 95:5, where 95% of the light is working light 8 and 5% of the light is sampling light; the set splitting ratio can also be 90:10, where 90% of the light is working light 8 and 10% of the light is sampling light.

[0028] In another exemplary embodiment of this application, the monitoring light sensor 7 is a silicon photodiode.

[0029] In another exemplary embodiment of this application, the aperture of the aperture 5 is 80% of the effective light-transmitting aperture.

[0030] In another exemplary embodiment of this application, the gain control module 9 reads the light intensity signal of the sampled light at a set sampling frequency.

[0031] In another exemplary embodiment of this application, the center wavelength of the LED light source 1 is 550nm.

[0032] The implementation principle and advantages of the LED light source control system in the above embodiments will be further explained below.

[0033] like Figure 1 As shown, LED light source 1, polarizer 2, analyzer 3, beam shaping assembly (lens 4 and aperture 5), and beam splitter 6 are arranged sequentially along the beam propagation direction. Monitoring light sensor 7 is arranged on the reflected light path of beam splitter 6. Gain control module 9 is electrically connected to monitoring light sensor 7, LED light source 1, and stepper motor 11.

[0034] LED light source 1 serves as the initial light-emitting component, outputting high-brightness, unpolarized light. Polarizer 2 converts the unpolarized light emitted by LED light source 1 into linearly polarized light. Analyzer 3 works in conjunction with polarizer 2, adjusting the relative angle between the polarization directions of analyzer 3 and polarizer 2 to achieve continuous optical modulation of the transmitted light intensity (Malus's Law). Lens 4 converges and gains the intensity of the modulated light after passing through analyzer 3, significantly reducing the size and weight of the optical system while maintaining high transmittance. Aperture 5 limits the beam aperture, filters stray light from the Fresnel lens edge, and improves beam quality. Beam splitter 6 splits the beam shaped by aperture 5 into two paths according to a set splitting ratio. The transmitted light serves as the system's main output working light 8, while the reflected light serves as the sampling light entering the monitoring light sensor 7. The monitoring light sensor 7 collects the intensity signal of the reflected light in real time and converts it into an electrical signal, which is then transmitted to the gain control module 9. The gain control module 9 (closed-loop feedback) receives the signal from the monitoring light sensor 7 and compares it with the preset standard light intensity threshold. When a decrease in light intensity is detected, the drive current of the LED light source 1 is increased through the electronic gain amplifier circuit, or the miniature stepper motor 11 is driven to finely adjust the rotation angle of the analyzer 3, thereby realizing dynamic gain compensation and stabilization of light intensity.

[0035] The following is a specific implementation process of the LED light source control system in practical applications.

[0036] The physical optical path of the LED light source control system is built on a vibration-resistant optical platform. First, a high-brightness LED light source 1 with a center wavelength of 550nm emits a diverging beam. A polarizer 2 is placed immediately behind it to convert the stray light waves into linearly polarized light in a single direction. Then, the beam passes through an analyzer 3 (mounted on a rotating frame with a high-precision stepper motor 11, whose transmission axis angle can be changed by external control) to a Fresnel lens. The focal length of this lens is precisely calculated so that the diverging beam is collimated into parallel light. The collimated parallel light passes through an adjustable aperture 5, the aperture of which is adjusted to 80% of the effective light-passing diameter, thereby cutting off diffraction fringes and stray light at the edges and ensuring the uniformity of the light spot. The shaped parallel light enters a beam splitter prism 6 with a splitting ratio of 95:5. 95% of the beam directly passes through the beam splitter prism 6 as the main light source output for use by downstream optical instruments, while 5% of the reflected light is perpendicularly incident on a high-sensitivity silicon photodiode (i.e., a monitoring light sensor 7). During system operation, the gain control module 9 reads sensor data at a sampling rate of 1kHz. When the luminous efficiency of the LED light source 1 decreases due to increased junction temperature and the light intensity detected by the sensor is lower than the set light intensity value, the gain control module 9 activates a dual compensation mechanism: it first calculates and outputs the gain current to the LED driver; if the current compensation reaches the saturation threshold, it drives the stepper motor 11 of the analyzer 3 to reduce the angle between the polarizer 2 and the analyzer 3, thereby restoring the brightness of the main output beam through "optical gain" and achieving long-term high brightness and extremely high stability irradiation.

[0037] The advantages of the LED light source control system in this embodiment are as follows: (1) High-precision optical modulation: The polarizer 2 and analyzer 3 are innovatively connected in series in the optical path, realizing the ability to finely adjust the light intensity without significantly changing the LED operating current, effectively avoiding spectral shift caused by sudden current changes. (2) Compact and lightweight design: Fresnel lenses are used instead of the traditional heavy collimating lens group, which greatly shortens the optical path length and reduces the system weight. (3) Closed-loop real-time stability: The beam splitter prism 6 and the monitoring light sensor 7 are located at the end of the optical path, which can most realistically reflect the state of the final output beam. Combined with the gain control module 9, the system has strong anti-interference ability and extremely high long-term operational stability.

[0038] Based on the same inventive concept, this application also provides an LED light source control method for implementing the LED light source control system described above. The solution provided by this method is similar to the implementation scheme described in the above system; therefore, the specific limitations in one or more LED light source control method embodiments provided below can be found in the limitations of the LED light source control system described above, and will not be repeated here.

[0039] In one exemplary embodiment, an LED light source control method is provided, comprising: (1) Obtain the light intensity signal of the sampling light collected in real time by the monitoring light sensor 7; the sampling light is the unpolarized light emitted by the LED light source 1 that passes through the polarizer 2, analyzer 3, beam shaping component and beam splitter 6 in sequence, and is reflected out by the beam splitter 6; the light transmitted and output by the beam splitter 6 is the working light 8.

[0040] (2) When the light intensity signal is lower than the set light intensity threshold, control the driving current of the LED light source 1 to increase or adjust the rotation angle of the analyzer 3 to perform dynamic gain compensation on the light intensity of the working light 8.

[0041] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0042] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An LED light source control system, characterized in that, include: The system comprises a polarizer, an analyzer, a beam shaping assembly, a beam splitter, a monitoring light sensor, and a gain control module. The polarizer, analyzer, beam shaping assembly, and beam splitter are sequentially arranged on the outgoing light path of the LED light source. The monitoring light sensor is arranged on the reflected light path of the beam splitter. The gain control module is electrically connected to the monitoring light sensor, the analyzer, and the LED light source. The LED light source is used to emit unpolarized light; the polarizer is used to convert the unpolarized light into linearly polarized light; the analyzer is used to modulate the linearly polarized light to obtain modulated light; the beam shaping component is used to shape the modulated light to obtain a shaped beam. The beam splitter is used to split the shaped beam into transmitted working light and reflected sampling light according to a set splitting ratio; the monitoring light sensor is used to collect the light intensity signal of the sampling light in real time; the gain control module is used to control the driving current of the LED light source to increase or adjust the rotation angle of the analyzer when the light intensity signal is lower than the set light intensity threshold, so as to perform dynamic gain compensation for the light intensity of the working light.

2. The LED light source control system according to claim 1, characterized in that, The beam shaping assembly includes: a lens and an aperture; The lens is used to converge and increase the intensity of the modulated light to obtain a processed beam; the aperture is used to limit the aperture of the processed beam, filter out stray light from the lens edge, and obtain a shaped beam.

3. The LED light source control system according to claim 1, characterized in that, Also includes: A stepper motor; the gain control module is electrically connected to the analyzer via the stepper motor.

4. The LED light source control system according to claim 2, characterized in that, The lens is a Fresnel lens.

5. The LED light source control system according to claim 1, characterized in that, The set splitting ratio is 95:5, where 95% of the light is working light and 5% is sampling light.

6. The LED light source control system according to claim 1, characterized in that, The monitoring optical sensor is a silicon photodiode.

7. The LED light source control system according to claim 2, characterized in that, The aperture of the aperture is 80% of the effective light-transmitting aperture.

8. The LED light source control system according to claim 1, characterized in that, The gain control module reads the light intensity signal of the sampled light at a set sampling frequency.

9. The LED light source control system according to claim 1, characterized in that, The center wavelength of the LED light source is 550nm.

10. A method for controlling an LED light source, characterized in that, The LED light source control method is applied to the LED light source control system according to any one of claims 1-9, and the LED light source control method includes: The light intensity signal of the sampling light collected in real time by the monitoring light sensor is obtained; the sampling light is the unpolarized light emitted by the LED light source, which passes through the polarizer, analyzer, beam shaping component and beam splitter in sequence, and is reflected by the beam splitter; the light transmitted and output by the beam splitter is the working light. When the light intensity signal is lower than the set light intensity threshold, the driving current of the LED light source is increased or the rotation angle of the analyzer is adjusted to dynamically compensate the light intensity of the working light.

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