Abstract— Reflective color LCDs with double polarizers have been developed by means of optimizing liquid‐crystal modes, aperture ratio, color‐filter properties, thickness of the glass substrate, polarizers, reflectors, etc. These LCDs are sufficiently bright, display many colors, have good hue, and are light weight with thin outline and low power consumption. Since they have double polarizers, a very high contrast ratio can be obtained. Therefore, they are superior in text character displays. Moreover, transflective color LCDs have been developed without visible deterioration of reflective displays by adoption of a reflective polarizer and backlight system in place of a lower polarizer and reflector.

A polarizing holographic optical element (HOE) with compensating grooves on the surface of a LiNbO3 substrate has good polarizing beam-splitter characteristics. This polarizing HOE was applied to a recordable optical head with an integrated laser and photodetector unit. In the optical head, a correct far-field tracking method is constructed by setting the polarizing HOE and a quarter-wave plate right under the objective lens, which can be moved with the objective lens. A holographic pattern of the polarizing HOE is divided into 20 portions along a disc track direction for spot size focus error detection and far field tracking detection. Wth this optical head, conventional CD play-back and recording signals on phase change discs were performed. Then the tracking offset caused by objective lens shift was measured and determined to be markedly decreased. Signal degradation by the ±1 st light diffracted by a polarizing HOE was not observed. Good characteristics of recording and play-back for phase change discs were also obtained. This recordable optical head was found to have desirable characteristics and high productivity.

This paper discusses MSA; a _Mobility support -Architecture for IP nodes o n a wireless telecommunication network. MSA has the capability of performing IP node location management, address resolution from an IP address t o an identification number of a node on a wireless telecommunication network, and virtual circuit control across IP subnetworks. MSA avoids redundant mobility management, and provides efficient routing to IP nodes on a wireless telecommunication network. In order t o accomplish the optimal route between IP nodes, MSA cooperates with the route optimization mechanism of IETF Mobile IP. As a result, MSA realizes an IP node on a wireless telecommunication network, which communicates optimally with other IP nodes on a wireless telecommunication network and other networks without any extensions except for a wireless telecommunication network interface module. We implemented a prototype system based on a kind of PCS. This paper concludes that MSA proposes a new mobile 1P mechanism suitable for IP nodes on wireless telecommunication network environments and proves its efficiency through measurement and consideration. I . INTRODUCTIONDigital wireless telecommunication systems have been emerging recently. Personal Communication Services (PCS) have been developed as one of them. They allow people to communicate everywhere in the world and provide them with multimedia services. Internet, on the other hand, is the largest world-wide communication platform, especially for computer communication. In order to combine the features of Internet and digital wireless systems, we have been carrying out research on a mobile terminal which not only has global wireless telecommunication connectivity but also I P reachability. In this combina.tion, we consider PCS as a n alternative network interface in place of Ethernet.PCS supports mobility of terminals. However, if a. Mobile Node (MN) employing the lnternet Protocol (IP) tries to roam over a PCS platform, the IP routing mechanism will be invoked prior to a mobility management mechanism included in PCS; as a result, all related communications to the MN will fail in the case that the MN is out of the IP subnetwork which MN's IP address belongs to. On the other hand, if the MN employs Mobile IP [6], Mobile IP routing mechanism will try to forward IP packets to the MN's care-of address. Then, the PCS platform will establish a connection to the MN by invoking its own mobility management mechanism. As we can see, the redundant mobility support from the. Mobile IP and PCS is a waste of resource. It depends on a care-of address assignment of the MN whether redundant forwarding occurs or not.We have explored an architecture which enables mobile IP nodes on PCS t o communicate with each other in a way that the communication routes are optimal. In this paper, we describe the architecture MSA; a _Mobzlzty Support Archztecture for IP nodes on a wzreless telecommunicatzon network. MSA has the capability of performing IP node location management, address resolution from an IP addr...

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An ordinary half-height size optical pickup with high light-use efficiency for Blu-ray Discs (BDs) has been realized. It has two objective lenses arranged tangentially. Although one of the objective lenses, BD objective lens, does not follow the line that passes thorough the center of the spindle motor, stable tracking-error detection has been achieved by enhancing a one-beam method. This pickup has a beam shaper which changes a divergent angle of light with high magnification. Although beam shapers are sensitive to a positional error, our pickup accomplished stable positioning by introducing a new structure.