Optical system of helmet mounted display based on free-form surface prism

Abstract

The invention relates to an optical system of a helmet mounted display based on a free-form surface prism. The optical system is the free-form surface prism formed by an S1 surface, an S2 surface and an S3 surface, wherein the S2 surface is a plane, and the S3 surface is a spherical surface. An overall coordinate system is firstly defined as follow: an original point O is positioned in the center of an entrance pupil; a Z axis is reversely traced from the center of the entrance pupil to the prism along a main optical axis L0; a Y axis is vertical to the Z axis and is positioned in the plane including the main optical axis L0; and an X axis is simultaneously vertical to the Y axis and the Z axis. A local coordinate system of each optical plane is then defined as follow: an original point is positioned on overall coordinates (SXi, SYi, SZi), a Zi axis passes through the original point of the local coordinate system and forms a thetai angle with the Z axis in the overall coordinate system, and a Yi axis passes through the original point and forms a right angle with the Zi axis in a symmetrical plane; and an Xi axis is vertical to coordinate axis of the Zi axis and the Yi axis, and a function expression of each optical plane is obtained according to the definition of the coordinate system, wherein a function expression of the S1 plane is a Zenike polynomial. The invention can realize the color display, effectively correct the aberration and improve the image quality.

Description

【Technical field】 [0001] The invention relates to the field of optical technology, in particular to a refraction-diffraction hybrid optical system for a light and small wide-spectrum free-form surface prism head-mounted display, which belongs to the field of optical system and device design, and is applicable to the fields of virtual reality and augmented reality. 【Background technique】 [0002] see figure 1 , The helmet-mounted display (HMD) is composed of a miniature image source and an optical system. The optical system displays a collimated image to infinity or far enough away for the pilot to observe normally through the partially reflective composite glass. In a see-through HMD, the image is superimposed with the external view and projected into the human eye. At present, most HMD optical systems are basically in the form of microscope erecting eyepieces. The whole system is roughly composed of three parts: relay optical system, eyepiece system and optical combinatio...

AI Technical Summary

Problems solved by technology

However, since the FFSM optical system only uses one kind of glass material, it cannot correct chromatic aberration and realize broadband display

Images