scholarly journals Focus-Adjustable Head Mounted Display with Off-Axis System

2020 ◽  
Vol 10 (21) ◽  
pp. 7931
Author(s):  
So Hyun Seo ◽  
Jae Myung Ryu ◽  
Hojong Choi
Keyword(s):  
Optical System ◽  
Optical Axis ◽  
Focal Length ◽  
Normal Vector ◽  
Effective Focal Length ◽  
Head Mounted Display ◽  
Conventional Methods ◽  
Angle Of Reflection

An off-axis system refers to an optical system in which the optical axis and the normal vector at the vertex of each surface do not match. An off-axis optical system can be applied in order to construct a thin and light optical system. In particular, the optical system used for a see-through head-mounted display (HMD) must be designed asymmetrically, with respect to the optical axis. Because the vision of a human is different for each individual, HMD requires focus adjustment. The effective focal length (EFL) of the optical system must be calculated to obtain the focus adjustment. However, the off-axis optical system cannot be calculated by conventional methods. In this study, the EFL was calculated by rotating the coordinates of the rays near the optical axis by the angle of reflection or refraction at the intersection of each surface, with the rays coinciding with the optical axis. The magnitude of movement of the micro-display for focus adjustment was obtained from the calculated EFL, for a see-through type HMD.

Design of cooled infrared switch-zoom optical system with long effective focal length based on R-C system

2014 ◽  
Vol 7 (2) ◽  
pp. 293-300
Author(s):  
李刚 LI Gang ◽  
杨晓许 YANG Xiao-xu ◽  
张恒金 ZHANG Heng-jin ◽  
孙东岩 SUN Dong-yan
Keyword(s):  
Optical System ◽  
Focal Length ◽  
Effective Focal Length

Spot size and effective focal length measurements for a fast axial flow CO2 laser

1997 ◽  
Author(s):  
Robert J. Steele ◽  
Phillip W. Fuerschbach ◽  
Danny O. MacCallum
Keyword(s):  
Co2 Laser ◽  
Focal Length ◽  
Axial Flow ◽  
Spot Size ◽  
Effective Focal Length ◽  
Length Measurements

Long focal length and large aperture zoom optical system

2021 ◽  
Author(s):  
Wei-jun Chang ◽  
Bo Zhang ◽  
Ge-ping Cao
Keyword(s):  
Optical System ◽  
Focal Length ◽  
Large Aperture

scholarly journals Optical Design of a Shortwave Infrared Dual Camera CASSI Based on Improved Offner-Wynne Imaging Spectrometer

2021 ◽  
Vol 2112 (1) ◽  
pp. 012021
Author(s):  
Chong Song ◽  
Lipeng Huo ◽  
Yong Huang ◽  
Yangdong Yan ◽  
Gang Wang ◽  
...  
Keyword(s):  
Optical System ◽  
Imaging System ◽  
Optical Measurement ◽  
Focal Length ◽  
Optical Design ◽  
Optical Transmittance ◽  
Coded Aperture ◽  
Visual Axis ◽  
Imaging Spectrometer ◽  
Shortwave Infrared

Abstract Based on the optical system characteristics of coded aperture snapshot spectral imager (CASSI), an optimized optical system of shortwave infrared dual camera CASSI was designed based on improved Offner-Wynne imaging spectrometer. The operating wavelength of the optical system ranges from 900nm to 1700nm, and the focal length is 1200mm. It consists of two parts: the two dimensional imaging system and the multispectral CASSI imaging system. The key technical parameters of the two parts are the same and there is no visual axis difference. Therefore, the optimized optical system can effectively improve real-time performance, optical transmittance and compactness of the dual camera shortwave infrared CASSI, which is conducive to the application in optical measurement scenes in the shooting range.

scholarly journals A proposed Mathematical Expression for Computer Design of Electrostatic Mirror

2012 ◽  
Vol 9 (1) ◽  
pp. 148-152
Author(s):  
Baghdad Science Journal
Keyword(s):  
Optical System ◽  
Focal Length ◽  
Mathematical Expression ◽  
Optical Element ◽  
Chromatic Aberration ◽  
Computer Design ◽  
Computational Investigation ◽  
Beam Path ◽  
Runge Kutta Method ◽  
Electrostatic Mirror

A computational investigation has been carried out on the design and properties of the electrostatic mirror. In this research, we suggest a mathematical expression to represent the axial potential of an electrostatic mirror. The electron beam path under zero magnification condition had been investigated as mirror trajectory with the aid of fourth – order – Runge – Kutta method. The spherical and chromatic aberration coefficients of mirror has computed and normalized in terms of the focal length. The choice of the mirror depends on the operational requirements, i.e. each optical element in optical system has suffer from the chromatic aberration, for this case, it is use to operate the mirror in optical system at various values of chromatic aberration to correct it in that system.

A Ray Transfer Matrix Model for an Elastomeric Lens

2011 ◽  
Vol 110-116 ◽  
pp. 4145-4148
Author(s):  
Johanna Mae M. Indias ◽  
Clark Kendrick C. Go
Keyword(s):  
Transfer Matrix ◽  
Matrix Model ◽  
Focal Length ◽  
Effective Focal Length ◽  
Length Changes ◽  
Variable Focus ◽  
Tunable Lens

A Ray Transfer Matrix (RTM) of a variable-focus elastomeric fluidic lens is explored and modeled in this paper. A HeNe (543.45nm wavelength) laser is incident on the tunable lens and the effective focal length changes are explored based on this model. Results show that there are two possible focal lengths and that focal lengths are independent of the elastomer thickness.

A NEW METHOD OF LENS CENTERING IN THE OPTICAL SYSTEM BY USING SPECIAL MOUNT

2021 ◽  
pp. 137-144
Author(s):  
Bao Bui Dinh
Keyword(s):  
Optical System ◽  
Optical Axis ◽  
Assembly Process ◽  
Optical Surface ◽  
Lens System ◽  
High Quality ◽  
Manufacturing Equipment ◽  
Influence Coefficients ◽  
Process Solutions

Decentration in lens systems (for example objectives) significantly degrades the quality of image, such as the coma. In order to reduce lens decentration, the lenses are centered while manufacturing, while gluing, while attachment in the mounts. Significant decrease in the lenses decentering in the mounts is achieved by using a special manufacturing equipment, which allow combining the optical axis of the lens with the base axis of the mount in assembly process. Solutions for coma's alignment by shifting, tilting and rotation their components are also provided in the construction of high-quality objectives (microscopes [1-7], photolithographic, aerophotographic). For optimization of methods for such adjustment the influence coefficients of decentering of each optical surface of the lens system on the value and sign of coma must be calculated and taken into account. In this paper, we propose a special mounting which combined with the Opticentric of Trioptics device to center the lenses. The results show that the decentering is significantly reduced (0.9µm) compared to (44.2µm) with using a reference mount.

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