A high frame rate sinusoidal stripe field projection module

Abstract

The invention belongs to the field of 3D measurement technology and provides a high frame rate sinusoidal stripe field projection module, which is particularly suitable for use in miniaturized 3D measurement equipment. The invention includes: a photoresist 1, an optical channel isolation seat 2, and a light-emitting chip mounting plate. 3. The projection imaging lens 4, the optical expansion lens 5 and the luminescent display channel control circuit 6. The luminescent chip, the optical channel isolation seat and the photoresist together form a luminescent array. The luminescent array contains several independent luminescent display channels; through the luminescent display The channel control circuit controls the light-emitting array to sequentially display three quasi-sinusoidal binary filling light-emitting patterns with a 120° phase shift relationship. Under the action of the projection lens and the light expansion lens, a three-step phase shift relationship is projected in the target area. Sinusoidal fringe field. The high frame rate sinusoidal field projection module of the present invention has an accurate phase shift relationship among the three sinusoidal fringe fields projected, and has the advantages of high projection frame rate, high production accuracy, low production cost, and simple module control.

Description

technical field [0001] The invention belongs to the technical field of 3D measurement, and mainly relates to a 3D measurement technology utilizing sinusoidal fringe structured light, in particular to a high frame rate sinusoidal fringe field projection module. Background technique [0002] Structured light 3D measurement equipment projects structured light onto the target to be measured, shoots the target with a camera, and realizes 3D measurement by processing the captured pictures; the sinusoidal fringe light field is one of the most commonly used structured light, using the sinusoidal fringe projection and phase shift method 3D shape measurement technology has the advantages of high resolution and high precision, and has been widely used in many fields. Sinusoidal fringe projection technology is one of the core technologies of phase-shift 3D measurement, and it has also undergone a long-term research process. In the early days, grating lamps with sinusoidal changes in tr...

AI Technical Summary

Problems solved by technology

In order to achieve high-speed 3D measurement, scholars have proposed a method of displaying square wave binary patterns with DFP, combined with the method of defocusing to obtain an approximate sinusoidal projection light field, and using DLP Discovery technology to successfully achieve 667Hz high-speed 3D measurement, and potential The projection frame rate reaches tens of kHz, but the sinusoidal fringes produced by this method are approximate, which makes the measurement results have a large error, and the relationship between the fringe quality and the degree of defocus is large, which is not convenient for application; in order to use Due to the high-speed performance advantages of the binary pattern display method, there has been a lot of research work on optimizing the projected binary pattern, including one-dimensional optimized patterns using waveform optimization, and two-dimensional optimized patterns using dithering techniques, where two-dimensional optimized patterns enable very close focus A good sinusoidal fringe field can also be obtained in the state of The degree of defocus still has an impact on the accuracy of the measurement results, and the degree of defocus is not easy to control

In any case, due to the programmable nature of DFP and the high frame rate projection performance based on DLP Discovery technology, the DFP projection of binary patterns combined with out-of-focus projection has become the mainstream technology for high-speed 3D measurement; however, the high frame rate DFP projection technology adopts The cost of the device is high, and the control is relatively complicated, which is not conducive to reducing the cost of the equipment, and it is not suitable for the equipment that requires a small overall size; in addition to the DFP projection method, scholars have also studied some other methods, including high-speed rotating grating disk Mechanical methods, laser interference methods, methods based on channel selection, etc., are used to achieve high frame rate projection, but the methods used have their own problems and are difficult to be effectively applied

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