Exit Pupil Distance Research Articles

Head-mounted displays based on human eye condition variation patterns

In response to the practical demands for a wide field of view (FOV), long exit pupil distance, and high image quality in head-mounted displays, an initial structure was built based on the principles of catadioptric lenses in a folded optical path (pancake optics) and the field curvature correction formula. Subsequently, using even-order aspheric surfaces, a VR optical system was developed with a FOV of 2w=110∘, an exit pupil distance of 15 mm, and an exit pupil diameter of 8 mm. Compared to traditional designs, a human eye model was introduced as the image plane to construct a VR–human eye optical system analysis model, allowing for direct analysis of the retinal image quality under different states of the human eye. After that, based on medical statistical data, the impact of different light intensity conditions on the retinal image quality of the VR optical system was explored. Experimental results showed that changes in light intensity affect the pupil diameter, which, in turn, influences the final image quality of the system. To solve the issues, two solutions were proposed: adjusting the screen distance and changing the lens spacing. Both methods significantly improved the imaging quality on the human retina, with an increase of over 30% in the average MTF value. A comparison of these methods was conducted, providing valuable references for future VR optical system designs.

Design of a dynamic target simulator optical system with a large FOV and long exit pupil distance.

According to new generation missile test and detection requirements, it is necessary to introduce hardware-in-the-loop (HIL) simulation technology to realize the performance test of the seeker. This paper introduces the concept of secondary imaging and uses the method of focal distance allocation so that the optical system field of view (FOV) can still be greater than 6°, under the condition that the exit pupil distance is larger than 800mm and a high-quality lighting system is designed. The design results show that when the exit pupil distance of the system is 1000mm and the FOV is 6.4°, the modulation transfer function (MTF) of the system is 60l p/m m>0.4, and the distortion is less than 0.1%. The uniformity of the illumination system is greater than 90%, meeting the requirements of the design index.

FEA based opto-mechanisms design and thermal analysis of a dynamic SFS with an ultra-long exit pupil distance

The dynamic star field simulator (SFS) reproduces the actual operating conditions for the star tracker (STR) to assess its performance along with the flight motion simulator (FMS) in the hard-ware-in-the-loop (HWIL) simulation. The exit pupil distance of a traditional SFS is extremely short, which limits its application to large FMSs. To project the liquid crystal on silicon (LCoS) output to the STR entrance pupil, a 1250 mm ultra-long exit pupil distance SFS, operating in the broad waveband of 450–900 nm, is designed and implemented. In this study, the opto-mechanisms design and thermal analysis of the SFS are evaluated. The detailed design for key assemblies is specifically addressed to suppress negative heat effects. From the finite element analysis (FEA) results under different thermal conditions, the Zernike coefficients of 16 deformed optical surfaces in the projection module are solved using singular value decomposition (SVD), and the temperature adaptability is verified using a ray-tracing software. The preliminary SFS assessment confirms the simplicity of manufacture and excellent performance. The closed-loop opto-mechanisms design significantly improves the SFS reliability and enhances its suitability for large FMS use.

Optical design of miniaturized laser communication receiving telescope with long exit pupil distance

Optical design of miniaturized laser communication receiving telescope with long exit pupil distance

AUTOMATED DESIGN OF THE OPTICAL SYSTEM OF THE ZOOM RIFLESCOPE

It is proposed to perform an automated design of a multi-lens optical system of a zoom riflescope by using one of modern global optimization algorithms, namely the adaptive Cauchy differential evolution method. The optical system considered here provides the magnification 4-16× and the angular field of view in the object space from 5.15° to 1.32°. It has the entrance pupil diameter of 42 mm, the exit pupil distance within 85...90 mm, and the maximum system length of 325 mm. The riflescope contains 14 lenses in 9 components made of glasses from the CDGM catalog. In all zoom configurations of the optical system, any ray vignetting is absent. To achieve the high image quality, the parametric synthesis of the riflescope has been carried out simultaneously for five intermediate configurations, corresponding to magnifications 16×, 13×, 10×, 7× and 4×. By using the developed specialized software, an experimental examination of the operability of this approach has been performed on the example of automated design of the optical system having the parameters similar those found in commercially available samples. The performed simulation showed that the time interval required for direct automated design of the riflescope’s optical system is about 25 hours. The total number of unknown parameters (variables) was up to 90. The root-mean-square values ​​of the angular aberrations of the axial beams in all (five) configurations of the synthesized zoom system do not exceed 1 arc minute in the whole spectral range. The obtained results indicate that the design algorithm implemented in the computer program can be considered an effective tool capable to perform automated parametric synthesis of complex zoom optical systems with high image quality. The algorithm enables to establish the prescription data of optical systems, taking into account the technical requirements and restrictions specified by the designer.

P‐66: Application of Ergonomics in VR HMD Exit Pupil Positioning Design

To achieve the actual exit pupil distance and ensure display effect of the VR HMD, the positioning structure of exit pupil is studied from three aspects:design data extraction, experimental verification and data compensation. The surface model of sponge which is used to ensure the best fit between the sponge and face is extracted according to the data of ergonomic dimensions. The sponge designed with this model should be made to measure the actual exit pupil distance of the VR HMD by the method studied in this paper. The data of sponge compression from the test should be added to the size before. According to this method, the actual exit pupil distance can be closest to the design to achieve the best display effect.

Optical-Digital Integrated Design Method for Near-Eye Display Imaging System

Near-eye display (NED) systems have various structures, including the freeform prism, off-axis synthesizer, and holographic optical waveguide structures. In this study, the three types of structures of NED systems were analyzed in terms of their advantages and disadvantages. Hence, an optical-digital integrated design method was proposed for the NED imaging system. In particular, a point spread function model with aberration information was developed based on the analysis of optical system aberration. Algorithm preprocessing was conducted on the image-end, and the processed image was transformed into a sharp image by the optical system and sent to the pupil. A NED optical system with a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$45^{\circ } \times32$ </tex-math></inline-formula> ° field of view, 10-mm exit pupil diameter, and 30-mm exit pupil distance was developed using the proposed method. This system can meet the NED requirements using three aspherical reflectors instead of a free-form and lens-correction group.

长出瞳距离轴四反光学天线的设计研究

长出瞳距离轴四反光学天线的设计研究

Design of optical system based on DMD for simulator with large field of view and long exit pupil distance

Design of optical system based on DMD for simulator with large field of view and long exit pupil distance

Design of an ultra-thin near-eye display with geometrical waveguide and freeform optics

Small thickness and light weight are two important requirements for a see-through near-eye display which are achieved in this paper by using two advanced technologies: geometrical waveguide and freeform optics. A major problem associated with the geometrical waveguide is the stray light which can severely degrade the display quality. The causes and solutions to this problem are thoroughly studied. A mathematical model of the waveguide is established and a non-sequential ray tracing algorithm is developed, which enable us to carefully examine the stray light of the planar waveguide and explore a global searching method to find an optimum design with the least amount of stray light. A projection optics using freeform surfaces on a wedge shaped prism is also designed. The near-eye display integrating the projection optics and the waveguide has a field of view of 28°, an exit pupil diameter of 9.6mm and an exit pupil distance of 20mm. In our final design, the proportion of the stray light energy over the image output energy of the waveguide is reduced to 2%, the modulation transfer function values across the entire field of the eyepiece are above 0.5 at 30 line pairs/mm (lps/mm). A proof-of-concept prototype of the proposed geometrical waveguide near-eye display is developed and demonstrated.

The Design of a Hybrid Diffractive-Refractive Wide-Angle Eyepiece with a Large Exit Pupil Distance

The diffractive optical elements, with the negative dispersive characteristic and the random phase distributing to realize random phase modulation for wave-front, are not only helpful to simplify the optical system, but also improve the image quality, while putting it into the optical system. It can decrease the element numbers of the system and obtain a compact configuration that introducing diffractive optical element into the design of eyepiece. A hybrid diffractive-refractive wide-angle eyepiece, with a big exit pupil distance, is designed by using the Code V Optical Design Software. The features of the wide-angle eyepiece are 30mm effective focal length, 60°whole field-of-view (FOV), 30mm exit pupil distance and 6mm exit pupil diameter, and which consists of four lens and two diffractive elements. From the result of design, the MTF in the center field of the wide-angle eyepiece is over 0.55at 60lp/mm, at the same time, the MTFs in all fields are over 0.3 at 50lp/mm, which show that this wide-angle eyepiece has a great image quality.