High-frame-rate sine fringe field projection module

Abstract

The invention belongs to the technical field of 3D measurement, and provides a high-frame-rate sine fringe field projection module, which is particularly suitable for being used in miniaturized 3D measurement equipment. The projection module comprises a photoetching sheet 1, an optical channel isolation seat 2, a light-emitting chip mounting plate 3, a projection imaging lens 4, a light expansion lens 5 and a light-emitting display channel control circuit 6, a light-emitting chip, the optical channel isolation seat and the photoetching sheet jointly form a light-emitting array, and the light-emitting array comprises a plurality of independent light-emitting display channels; the light-emitting array is controlled by the light-emitting display channel control circuit to sequentially display three sine-like binary filling light-emitting patterns with a 120-degree phase shift relation, and a sine stripe field with a three-step phase shift relation is projected in a target area under the action of a projection lens and a light expansion lens. The phase shift relation of the three sine fringe fields projected by the high-frame-rate sine fringe field projection module is precise, and the high-frame-rate sine fringe field projection module has the advantages of high projection frame rate, high manufacturing precision, low manufacturing cost, simple module control and the like.

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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