Collimating lens, laser module, depth camera and electronic device

Abstract

The invention discloses a collimating lens, a laser module, a depth camera and an electronic device. The collimating lens sequentially comprises a first lens with positive focal power, a second lens with negative focal power, a third lens with positive focal power and a fourth lens with positive focal power from an object side to an image side. The object side surface and the image side surface of the first lens are convex surfaces. The object side surface and the image side surface of the second lens are concave surfaces. The object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface. The object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface. The first lens, the second lens and the third lens are all plastic lenses, the fourth lens is a glass lens, and the object side surfaces and the image side surfaces of the first lens to the fourth lens are aspheric surfaces. The collimating lens, the laser module, the depth camera and the electronic device effectively control the change of focal lengths at different temperatures through the matching design of the surface types and materials of the first to fourth lenses, thereby guaranteeing the imaging precision of depth images at different temperatures.

Description

technical field [0001] The present application relates to collimating lens technology, in particular to a collimating lens, a laser module, a depth camera and an electronic device. Background technique [0002] In the current 3D structured light depth camera, the laser emitter emits laser light, the laser beam is collimated by the collimator lens and shoots to the target object, the laser light is reflected by the target object and then received by the depth camera to form a speckle image, and according to the speckle image and A depth image is generated from a reference image. However, as the temperature in the use environment changes, the focal length of the lens will also change greatly, resulting in a significant change in the field of view and spot size of the light information projected from the lens to the object under test, which further leads to depth An error occurs in the calculation of the camera, which affects the imaging accuracy of the depth image. Contents...

AI Technical Summary

Problems solved by technology

However, as the temperature in the use environment changes, the focal length of the lens will also change greatly, resulting in significant changes in the field of view and spot size of the light information emitted from the lens and projected to the measured object, which further leads to depth Errors occur in the calculation of the camera, which affects the imaging accuracy of the depth image

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