scholarly journals Design of Wide Angle and Large Aperture Optical System with Inner Focus for Compact System Camera Applications

2019 ◽  
Vol 10 (1) ◽  
pp. 179 ◽  
Author(s):  
Hojong Choi ◽  
Jaemyung Ryu
Keyword(s):  
Optical System ◽  
High Speed ◽  
Resolving Power ◽  
Wide Angle ◽  
Phase Detection ◽  
Half Angle ◽  
Stepper Motors ◽  
Angle Of View ◽  
Floating Type ◽  
Focusing Lens

Conventionally, a bright, very wide-angle optical system is designed as a floating type optical system that moves two or more lens groups composed of multiple lens in order to focus accurately. These have been widely used as phase detection auto focus (AF) methods within conventional digital single-lens reflex (DSLR) cameras. However, a phase detection AF optical system cannot be used when recording motion pictures. In contrast, a compact system camera (CSC) performs AF by the contrast method, where a stepper motor is used as the driving source for moving the optical lens. Nonetheless, to ensure that the focusing lens is lighter, these stepper motors should not have high torque and AF must be possible by moving only one lens. Yet, when focusing is performed with only one lens, aberration change due to focusing lens movement is magnified. Therefore, a very wide-angle optical system comprised of a half-angle of view more than 40 degrees and F of 1/4 has not been developed. Here, a very wide-angle optical system was designed with high resolving power that enables high speed AF, even in contrast mode, by moving only one lens while minimizing aberration change.

scholarly journals Laser Lens Size Measurement Using Swept-Source Optical Coherence Tomography

2020 ◽  
Vol 10 (14) ◽  
pp. 4936
Author(s):  
Pingping Jia ◽  
Hong Zhao ◽  
Yuwei Qin
Keyword(s):  
Optical Coherence Tomography ◽  
High Speed ◽  
Wave Number ◽  
Radius Of Curvature ◽  
Optical Coherence ◽  
Swept Source ◽  
Laser Focusing ◽  
Fitting Algorithm ◽  
Laser Confocal Microscope ◽  
Focusing Lens

A high-speed, high-resolution swept-source optical coherence tomography (SS-OCT) is presented for focusing lens imaging and a k-domain uniform algorithm is adopted to find the wave number phase equalization. The radius of curvature of the laser focusing lens was obtained using a curve-fitting algorithm. The experimental results demonstrate that the measuring accuracy of the proposed SS-OCT system is higher than the laser confocal microscope. The SS-OCT system has great potential for surface topography measurement and defect inspection of the focusing lens.

Fisheye Lens Distortion Calibration Based on the Lens Charactetic Curves

2014 ◽  
Vol 519-520 ◽  
pp. 636-639
Author(s):  
Bao Long Zhang ◽  
Shao Jing Zhang ◽  
Wei Qi Ding ◽  
Hui Shuang Shi
Keyword(s):  
Optical System ◽  
Characteristic Curve ◽  
Calibration Method ◽  
Lens Distortion ◽  
Wide Angle ◽  
Forming Process ◽  
Fisheye Lens ◽  
Large Scope ◽  
Wide Angle Lens ◽  
Barrel Distortion

The fisheye lens is a kind of ultra wide angle lens, which can produce a big super-wide-angle lens distortion. In order to cover a large scope of light, barrel distortion is artificially added to the optical system. However, in some cases this distortion is not allowed, then it requires calibrations of those distortions. Most of the traditional distortion calibration method uses target plane calibration to do it. This paper discusses the way of design fisheye lens, through which we can know the forming process of distortion clearly. Based on this paper, a simple and effective calibration method can be understood. Different from common camera calibration method, the proposed calibration method can avoid the error occurring in the process of calibrating test, that directly use the lens’ characteristic curve. Through multiple sets of experimental verifications, this method is effective and feasible.

A Fixed-Focus Broad-Range Echelle Spectrograph of High Speed and Resolving Power*

1952 ◽  
Vol 42 (10) ◽  
pp. 706 ◽  
Author(s):  
George R. Harrison ◽  
James E. Archer ◽  
Jean Camus
Keyword(s):  
High Speed ◽  
Resolving Power ◽  
Echelle Spectrograph

scholarly journals Beam-smoothing effect in broad-band random-phase irradiation

1993 ◽  
Vol 11 (2) ◽  
pp. 385-390 ◽  
Author(s):  
I. Matsushima ◽  
Y. Owadano ◽  
Y. Matsumoto ◽  
I. Okuda ◽  
T. Tomie ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Optical System ◽  
Random Phase ◽  
Broad Band ◽  
Laser Fusion ◽  
Phase Plate ◽  
Smoothing Effect ◽  
Broad Bandwidth ◽  
A New Technique ◽  
Focusing Lens

A new technique to achieve smooth laser irradiation profiles on laser fusion targets is evaluated numerically and experimentally. In this technique, smoothing is obtained by using a spectral dispersing optic and a random-phase plate placed in front of a focusing lens employing the broad-bandwidth of KrF lasers. Experimental results and numerical calculations agree well, verifying that this simple optical system is effective for smooth irradiation on targets.

Web-Based, Interactive Laboratory Experiment in Turbomachine Aerodynamics

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Nalin Navarathna ◽  
Vitalij Fedulov ◽  
Andrew Martin ◽  
Torsten Fransson
Keyword(s):  
High Speed ◽  
Communication Technologies ◽  
Web Based ◽  
Laboratory Exercise ◽  
Pressure Profiles ◽  
Laboratory Facility ◽  
Stepper Motors ◽  
Loss Coefficients ◽  
And Control ◽  
Local Laboratory

Remote laboratory exercises are gaining popularity due to advances in communication technologies along with the need to provide realistic yet flexible educational tools for tomorrow’s engineers. Laboratory exercises in turbomachinery aerodynamics generally involve substantial equipment in both size and power, so the development of remotely controlled facilities has perhaps not occurred as quickly as in other fields. This paper presents an overview of a new interactive laboratory exercise involving aerodynamics in a linear cascade of stator blades. The laboratory facility consists of a high-speed fan that delivers a maximum of 2.5 kg/s of air to the cascade. Traversing pneumatic probes are used to determine pressure profiles at upstream and downstream locations, and loss coefficients are later computed. Newly added equipment includes cameras, stepper motors, and a data acquisition and control system for remote operation. This paper presents the laboratory facility in more detail and includes discussions related to user interface issues, the development of a virtual laboratory exercise as a complement to experiments, and comparative evaluation of virtual, remote, and local laboratory exercises.

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