LED light source image detection method and device with stroboscopic suppression function

Abstract

The invention discloses a method and device for detecting an image of an LED light source with a stroboscopic suppression function. The method steps include: S1. Determine an optimal exposure time for a target image sensor, so that the target image sensor collects samples to be measured according to the optimal exposure time. There is no LED stroboscopic effect in the image of the LED light source; S2 reduces and adjusts the light input of the target image sensor according to the determined optimal exposure time, so as to reduce the light input of the target image sensor to avoid overexposure, and determine the adjusted light input ; S3. The control target image sensor collects the image of the LED light source to be tested for detection according to the optimal exposure time determined in step S1 and the light input amount adjusted in step S2. The invention can suppress the LED stroboscopic effect when detecting the LED light source, and at the same time avoid the overexposure phenomenon.

Description

technical field [0001] The invention relates to the technical field of LED light source detection, in particular to a method and device for detecting an image of an LED light source with a stroboscopic suppression function. Background technique [0002] As a diode device, LED can only pass direct current. When connecting to the mains, it must use the power supply to convert the alternating current of the mains into direct current, and the response time of the luminous brightness of the LED to the current is very short, and it will change with the change of the current, that is, the LED The amount of current passing through is proportional to the brightness of the light, and the amount of current passing through is proportional to the amount of light emitted. Therefore, LED flickering is only related to the frequency and ripple of the output current of its driving power supply. The stroboscopic effect of the LED light source is essentially that the light emitted by the light ...

AI Technical Summary

Problems solved by technology

[0003] Since the LED lamp is driven by AC, the flickering frequency of the LED is generally 100Hz (twice the mains frequency), that is, the pulse period is about 10 milliseconds, and the LED will be turned on and off once within 10 milliseconds, which is energy-saving and prolongs the use. Life, the duty cycle is usually set to no more than 50%, so when the camera captures the image of the LED light, if the camera exposure time is short (for example, 3 milliseconds), it is possible that the camera exposure time is just in the period when the LED is turned off , so that what the image sensor collects at this time is the image of the LED off. If the LED array is collected, in this case the image captured by the camera will show a part of the light and a part of the dark state, making it impossible to obtain from LED lights detected in the image

[0004] For example, electronic road signs, traffic signals, etc., and car tail lights usually use LED lights. At present, when detecting such LED lights such as electronic road signs, traffic signals, etc., car tail lights, etc., usually use ordinary cameras directly to capture pictures according to a fixed exposure time. , it is very easy to have the above-mentioned LED stroboscopic effect. The existence of the LED stroboscopic effect will cause the system to fail to detect electronic road signs and traffic lights, and cannot distinguish between turn signals and tail lights, etc., and even cause serious traffic accidents.

The photosensitive ability of the image sensor is certain, that is, its exposure is limited. If the above-mentioned stroboscopic effect problem is simply solved by dynamically increasing and adjusting the exposure time, if the exposure time is too long, there will be a problem of overexposure. To eliminate stroboscopic flicker, the exposure time of a conventional ordinary camera needs to be set at least greater than 7ms, and under this exposure time, some traffic lights will be brighter due to the large duty cycle of the LED bright cycle, and when working outdoors The superposition of ambient light, especially in the case of sufficient sunlight at noon, can easily lead to overexposure of the camera image, and long-term exposure can also cause problems such as motion blur effects

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