• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.964-967
• /
• 2001

Aspherical lens with the higher numerical aperture has been needed in the optical storage device to increase the recording density on the disk. However, high numerical aperture means the large slope angle at the clear aperture of the lens. Therefore, the measurement and manufacturing technique including the lens molding process for the slope angle should be developed. In this paper, the evaluation technique was described for the optical performance of the aspherical lens. Aspherical form error brings about the wavefront error and the side lobe of the beam intensity profile. A schematic diagram of the aspherical lens manufacturing was drawn to explain the aspherical form error compensation. Finally, form error of the aspherical lens was defined and plotted using the raw data of the Formtalysurf.

• Korean Journal of Optics and Photonics
• /
• v.19 no.4
• /
• pp.327-333
• /
• 2008

In general, a lens with large NA makes image quality better. There are many kinds of cheap concave mirrors with large aperture and NA. This paper presents a method that uses a large aperture projection imaging system to enhance the image used for 3D shape measurement. This method makes it possible to enhance reflection uniformity on the object surface and increases SNR (Signal to Noise Ratio). Using a large aperture lens, it is possible to obtain a brighter image, reducing the shading nature in the image boundary, and enhancing the reflection uniformity even on woven surfaces. Because of the exorbitant cost of a large aperture projection lens larger than 150 mm in diameter, a refractive lens was exchanged with a concave mirror resulting in the same optical effect. In experiment, changing NA $0.15{\sim}0.8$, image contrast was enhanced from 46 to 1.33. Incidentally, the effect of the concave mirror was tested successfully through the experiment.

• Journal of Information Display
• /
• v.2 no.1
• /
• pp.43-46
• /
• 2001

To meet the demand of the display market for large, flat, high-resolution screen, the Super Common eXtended field Oval lens (S-CXO) has been developed with resolution improvement of 10% or more compared to a conventional electron gun. A new main lens structure is adopted, to enhance the effectiveness of aperture and the performance. The new main lens can be assembled using an existing assembly system

• ETRI Journal
• /
• v.31 no.2
• /
• pp.105-110
• /
• 2009

In this paper, we propose a curved projection integral imaging system to improve the horizontal and vertical viewing angles. The proposed system can be easily implemented by additional use of a large-aperture convex lens in conventional projection integral imaging. To obtain the simultaneous display of 3D images through real and virtual image fields, we propose a computer-generated pickup method based on ray optics and elemental images, which are synthesized for the proposed system. To show the feasibility of the proposed system, preliminary experiments are carried out. Experimental results indicate that our system improves the viewing angle and displays 3D images simultaneously in real and virtual image fields.

• Journal of Korean Ophthalmic Optics Society
• /
• v.5 no.2
• /
• pp.119-125
• /
• 2000

We analyzed to calculate optical capacity after we chose established 2 component zoom copier lens system in this research. As the lens system is zoom lens system of finite object point, it has moving area limited not like to use generally camera zoom lens of infinite object point because it moves between object and image plane. The magnification of optical system can obtain -1.41~-0.64 i.e., extended or shortened image as transverse magnification, and it acquires f/12 and about $20^{\circ}$ field of view. Although this 2 component zoom copier lens system will be down resolution and dark compared with f/2.8 acquired at camera lens, it will be possibile to be able to make large aperture and it can acquire more better correct aberration with the addition of auxiliary group forward or backward.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2006.05a
• /
• pp.164-167
• /
• 2006

Micro lens especially for optical pick up(Blu-ray) lens module is one of the key products for IT technology. Specific attention has been given to manufacturing of large radius lens but little to small radius less than 2mm diameter with N.A>0.8. This paper deals with a high precision glass molding technology for mass production of Blu-ray pick up lens. Ultra precisely machined tungsten carbide core and glass molding equipments are utilized for forming process. Evaluation was performed in terms of profile accuracy, surface roughness and thickness of fabricated glass lens.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.20 no.1
• /
• pp.113-122
• /
• 2002

We designed the illumination optical system to use Fresnel lens which is the most general type of large aperture system. The normal construction of Fresnel lens is a thin molded piece of material, usually some kind of plastic, with one side flat and the other comprising a series of concentric segments each angled in a way to provide for optimum focusing for a pair of conjugate points. The 155 mm Marine Signal Lantern is the approved for use on buoys and a maximum omnidirectional range of 8 nmi, can be obtained with standard 12V equipment, respectively. Finally, Fresnel lens with 155 mm diameter was designed and evaluated. Also, we re-designed groove "out" of Fresnel lens and compared results of groove "in" type with groove "out" type. According to the results, Fresnel lens is obtained best optical results when grooved side faces the longer conjugate.de faces the longer conjugate.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• fall
• /
• pp.144-145
• /
• 2021

Variable range of focal length of Moiré lens is designed to change the phase pattern, which is varifocal lens system using two thin layers with Moiré pattern and suitable to applied to AR/VR system because of the relatively simple structure, large aperture size, and wide variable range. We analyze the change of focal length region according to the phase pattern and verify the design to make the prototype patterns using DOE.

• The Journal of the Acoustical Society of Korea
• /
• v.9 no.2
• /
• pp.5-13
• /
• 1990

In this paper, 50MHz reflection ultrasonic microscope system with small aperture acoustic lens has been constructed in order to study the defects which lay deep in thick specimens, and acoustic images of multilayered media have been analyzed. Output characteristics of this system for multilayered media have been influenced by acoustic attenuation, aberration in specimen, type of lens and the properties of a defect, and it has been used for image processing of the multilayered I.C. and the bonding layer. In experimental results, it has been shown that small aperture ultrasonic microscope system was powerful tool for inspection of thick specimens such as electronic device, bonding layer, quality of ceramic materials.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1799-1802
• /
• 2007

In the constructed auto-stereoscopic display system for one observer. 1.stereoscopic images displayed on a special LCD are made on a large concave mirror. 2.The view-zone limiting aperture is set between the projection lens and the concave mirror. 3.The real image of the aperture is made at the observer's eye position by the concave mirror. 4.The observer's eye-position tracking of the view-zone is realized. 5.At same time, stereoscopic image changes automatically according to the eye position of the observer.