Video camera system using liquid-crystal polarizing filter toreduce reflected light

We have been developed a video camera system using an electrically-controllable liquid crystal polarizing filter for television program production, which can quickly reduce undesirable reflected light from a window pane or watery surface, by automatically judging the polarization state of incident light from the change in video signal intensity. More than 80% of linearly-polarized incident light is removable by this method for all incident polarization angles. The time required for detecting and reducing reflected light is approximately 0.3s in our system. The drastic reduction of polarized light reflected from glass and watery surfaces was demonstrated, and object images obscured by bright reflected light were clearly captured in an instant     

Residual flexural behavior of fiber reinforced concrete after heating

In this study, the effects of fire on the flexural performance and residual strength of plain and fiber reinforced concrete are investigated. Three types of concrete are tested: plain, polypropylene (PFRC) and steel fiber reinforced concrete (SFRC). Prior to the flexural test, the specimens were exposed to fire for 15, 30, 45, and 60 min on a furnace. The burnt specimens were then tested under flexural load to measure their toughness and residual strength. Results indicate the reduction of flexural strength for both plain and FRC after being subjected to fire. For FRC, the effect of fire on the flexural response depends mainly on the fiber type and fire exposure duration. For PFRC, the flexural strength is found to drop significantly for every exposure duration, while toughness is found to increase at short exposure duration and then, drop quickly after long exposure duration due to the fiber evaporation effect. For SFRC, the flexural strength and toughness are found to drop gradually for every exposure duration due to the deterioration of cement paste and reduction in bond strength. SFRC exhibits a more consistent ability to maintain load carrying capacity after long exposure to fire than PFRC.     

Clinical results of three types of intraocular lenses for small incision surgery

We implanted three types of intraocular lens (IOL) in 30 eyes each by small-incision surgery. They were: foldable acryl IOL, foldable silicone IOL and polymethylmethacrylate (PMMA) IOL. We evaluated the following items during three years after surgery: visual acuity, astigmatism, glare disability, contrast sensitivity, tilt and decentering of IOL, corneal endothelial population, aqueous flare and aftercataract. Eyes foldable IOLs were more excellent than PMMA IOLs regarding visual acuity, astigmatism and aqueous flare which are indices for the early postoperative period. PMMA and acryl IOLs were more excellent than silicone IOLs regarding decentration of IOL and aftercataract which are indices for the late postoperative period.     

Flexible color LCD panel driven by low‐voltage‐operation organic TFT

Abstract— A flexible color LCD panel driven by organic TFTs (OTFTs) was successfully demonstrated. A pentacene OTFT with an anodized Ta₂O₅ gate insulator, which can be operated at low voltage, was developed. In order to improve the electrical performance of the OTFT, the gate insulator was surface treated by processes such as O₂ plasma, UV light irradiation, and hexamethyldisilane treatments. The fabricated OTFT exhibited a mobility of 0.3 cm²/V‐sec and a current on/off ratio of 10⁷ with a low operating drain voltage of ?5 V. A fast‐response‐time flexible ferroelectric LCD, which contains polymer networks and walls, was integrated with the OTFTs by using a lamination and a printing technique. As a result, color images were achieved on the fabricated panel by using a field‐sequential‐color method at a low driving voltage of less than 15 V_pp.     

Axi-vision camera (real-time distance-mapping camera)

The camera described here makes color TV images that include information about the distance between the camera and the objects in the images. This range information is obtained from two images of the same scene taken under different illumination conditions. The camera does not require scanning, multiple camera units, or complicated computation. Range information for each pixel is acquired fast enough to keep up with the video rate of a TV camera. We describe various operational features and technical specifications such as ranging errors as well as the results of experimental investigations of the dependence on the color and reflectivity of the objects, of the sensitivity to interference from external light, and of the effects of the movement of the objects.     

Spatial light modulators for high-brightness projection displays

We fabricated polymer-dispersed liquid-crystal light valves (PDLCLV's) consisting of a 30-mum-thick hydrogenated amorphous-silicon film and a 10-mum-thick polymer-dispersed liquid-crystal (PDLC) film composed of nematic liquid-crystal (LC) microdroplets surrounded by polymer. The device can modulate high-power reading light, because the PDLC becomes transparent or opalescent independent of the polarization state of the reading light when either sufficient or no writing light is incident on the PDLCLV. This device has a limiting resolution of 50 lp/mm (lp indicates line pairs), a reading light efficiency of 60%, a ratio of intensity of light incident on the PDLC layer to intensity of light radiated from the layer, and an extinction ratio of 130:1. The optically addressed video projection system with three PDLCLV's, LC panels of 1048 x 480 pixels as input image sources, a 1-kW Xe lamp, and a schlieren optical system projected television (TV) pictures of 600 and 450 TV lines in the horizontal and the vertical directions on a screen with a diagonal length of 100 in. The total output flux of this system was 1500 lm.     

Analysis of the electrofusion joining process in polyethylene gas piping systems

Electrofusion (EF) is a semi-automated technology for joining polyethylene gas distribution pipes. To design reliable EF joints, a computational model for the EF joining process needs to be established. In the present work, a simulation method for the EF joining process, in which the thermomechanical coupling behavior is taken into account, has been developed employing ADINA and ADINA-T. The method can be used to simulate the closure process of the clearance between the joint and the pipe. In addition, the histories of the interface pressure and the temperature distributions, the parameters which have a critical importance on the quality of the joint, can be obtained. First, the computed results were compared with the experimental data from a small scale EF joint and good agreement was obtained. Next, the method was applied to design a large scale EF joint and the design optimization was carried out, resulting in the successful development of a reliable joint.     

Low‐temperature fabrication of 5‐in. QVGA flexible AMOLED display driven by OTFTs using olefin polymer as the gate insulator

Abstract— A 5‐in. QVGA flexible AMOLED display driven by OTFTs has been fabricated at a low temperature of 130°C. A polyethylene naphthalate film was used as the flexible substrate and an olefin polymer was used as the gate insulator for the OTFT. This layer was formed by spin‐coating and baking at 130°C. Pentacene was used as the organic semiconductor layer. The OTFT performance to drive the flexible display with QVGA pixels in terms of current on/off ratio, carrier mobility, and spatial uniformity on the backplane have been obtained. Phosphorescent and fluorescent OLEDs were used as light‐emitting devices on a flexible display. Those layers were formed by vacuum deposition. After the flexible display was fabricated, a clear and uniform moving image was obtained on the display. The display also showed a stable moving image even when it was bent.