Kae-Dal Kwack

Methods for Displaying Three-Dimensional Images

The essential components of generating three-dimensional (3-D) images are defined, and various methods of creating each of the components are explained. The components are image acquisition, image multiplexing and processing, and display mechanisms. For image acquisition, transforming, synthesizing based on disparity, voxel and wavefront deformation, and sampling and photographing methods are used. For multiplexing, time, spatial, and spatiotemporal, and for processing, chirping, layering, and pixel cell based multiview image arrangement methods are used. The display mechanisms are classified into projection, contact,and scanning types depending on their means of displaying images. From these methods, 3-D images with real volume, with parallax only and with psychologically induced depth sense can be generated. The display mechanisms have another important mission of creating viewing zones. For this purpose, all 3-D imaging methods employ a special form of optics or mechanisms complying with their image multiplexing schemes. These optics and mechanisms are essential in realizing 3-D imaging systems but at the same time they provide many unfriendly and uncomfortable effects to viewers, and also impose some functional limitations.

About a MoirÉ-Less Condition for Non-Square Grids

The moire-less condition is found for non-square grids. The exact solution is found in form of a quartic equation depending on the geometric parameter. The root gives the optimal angle for minimized moires. The approximate solution is also found as well as the upper limit for residual moires. The proximity of the two solutions is proven. Experiments confirm the theoretical findings. The results can be used for minimizing moires in display devices which include several layers of regular grids.

Image-Forming Principle of Integral Photography

In this paper, viewing zone-forming geometry of multiview imaging systems and lens image forming principle is applied to prove that the depth sensing mechanism of integral photography (IP) is both parallaxes. The proof is based on the fact that making the cell size of each elemental image the same as a microlens pitch does not change the geometry, because there are no changes in the field-of-view of each microlens. The total number of different view images perceived in the viewing zone of IP, and the compositions of the images and condition of increasing the number are also identified.

A 1.8 V self-biased complementary folded cascode amplifier

This paper describes a 1.8 V self-biased complementary folded cascode(SB-CFC) amplifier. We propose a new self biasing scheme for the folded cascode amplifier which eliminates 6 external bias voltages and related biasing circuits. The required minimum power supply voltage is reduced to 1.8 V and the output voltage swings are increased. With our new self-biasing scheme the area and power overhead, susceptibility of the bias lines to noise and crosstalk, and design time are reduced.

Multiview Image Acquisition and Projection

A solution for describing both the multiview image set, obtained with a parallel camera layout, and the perceived image in a projection-type full parallax multiview imaging system with a parallel projector layout, is derived. This is done with the use of 4times4 homogenous matrices to quantitatively analyze the image quality in the system. The solution provides a means of finding properties and/or behavior of the perceived image changes depending on the viewers position in the system. The solution can analytically describe the appearance of three-dimensional images in the space generated by the multiview image set displayed on a projection screen

Optical parameters in ZnO nanocrystalline textured films grow on p-InP (100) substrates

Spectroscopic ellipsometry measurements on ZnO nanocrystalline textured films grown on p-InP (100) substrates by using radio-frequency magnetron sputtering at room temperature were carried out to investigate their optical parameters. Transmission electron microscopy measurements showed that ZnO thin films grown on p-InP (100) substrates were nanocrystalline. The dielectric function, the refractive indice, and the extinction coefficient of the ZnO thin films were determined as functions of the photon energy, and the energy gap of the ZnO nanocrystalline film was 3.38 eV. These results can help to improve the understanding of the ZnO nanocrystalline thin film grown on p-InP (100) substrates for potential use in optoelectronic devices based on InP substrates.

Stereoscopic image distortion in radial camera and projector configurations.

A closed-form solution of describing perceived image in stereoscopic imaging systems with radial recording and projecting geometry for arbitrary viewer positions is presented. This solution is derived by finding a condition for making the heights of homolog points in both left and right images projected on the screen in the geometry equal. The solution has the same equation form as that of the parallel geometry except that it has a constant shifting term in the horizontal direction. This term is a main source for distortions in the perceived image. The condition of eliminating the term makes the solution the same as that for stereoscopic imaging systems with parallel recording and projecting geometry.

A method of building pixel cells with an arbitrary vertex angle

Moire fringes appearing in contact-type three-dimensional imaging systems cause serious image quality deterioration. The fringes are inevitable because the systems require overlapping a viewing-zone-forming optical plate on a display panel. An analysis shows that the visual effects of the fringes can be minimized by finding a proper overlapping angle between the panel and the plate. This angle imposes that pixel cell in full-parallax imaging systems should have the shape of either rhombus or parallelogram with a specific vertex angle. The pixel cell with the shape of the rhombus or parallelogram is implemented by approximating the boundaries of each pixel cell by staircase lines drawn along sides of the pixel. The slopes of the lines are determined by the ratio of the pixel numbers in the vertical and horizontal directions. This method allows creating pixel cells with a desired vertex angle for minimizing the moire fringes, especially in full-parallax imaging systems.

Crystal Originated Particle Induced Isolation Failure in Czochralski Silicon Wafers

The presence of crystal originated particle (COP) on the 64 Mbyte dynamic random access memory (DRAM) device isolation region causes the current path between neighboring transistors, resulting in COP induced isolation failure. The probability of the COP induced isolation failure occurrence depends on the COP size; i.e., larger COP size leads to higher probability of failure. In addition, failure strongly depends on the process condition applied to the isolation structure, for example, the nitride film thickness; i.e., thicker nitride film results in a less probability of failure. Furthermore, failure also depends on the isolation structure itself; i.e., higher probability of the COP induced isolation failure follows local oxidation of silicon (LOCOS) > polysilicon space LOCOS (PSL) > selective polysilicon oxidation (SEPOX).

A novel driving system for high performance true color FED

This paper presents a novel driving system of a 5 inch true color FED using a voltage controlled PWM method with a current control effect. The proposed method has the advantage of both the voltage controlled pulse width modulation method and current control method. We propose an effective circuit model of a FED subpixel for circuit simulation of FED driving circuits. The output stage of the data driving circuit is optimized using the proposed circuit model. In video data processing, the FED controller uses the parallel processing of RGB input data, so the duty ratio increases. With these results, no noise and high quality performance is achieved in a 5 inch true color FED.