Tomohiro Sasagawa

A 65-in. slim (255-mm depth) laser TV with wide-angle projection optical system

— A high-definition laser TV that employs a newly developed laser light source and a super-wide-angle projection optical system has been developed. This adoption of a laser light source with three primary colors helped to achieve an extremely wide color gamut, and, in addition, a compact optical engine, which has been optimized to the laser light source and contributed to the achievement of the stylish design of a large screen of 65 in., with the depth being only 255 mm.

56.3: 65-inch, Super Slim, Laser TV with Newly Developed Laser Light Sources

A new light source for laser TVs has been developed along with a 65-inch super slim laser TV that employs the light source. In this stylish laser TV set, a depth of 255 mm has been realized owing to the new laser light source, a compact optical engine and a small laser drive power supply which are optimized to the light source.

19.3: Laser TV: Ultra‐Wide Gamut for a New Extended Color‐Space Standard, xvYCC

We have developed an HDTV that adopts semiconductor lasers involving three primary colors, red, green and blue for the light source. The adoption of a laser light source helped us realize a HDTV with a dramatically wide color gamut, namely 190% the color gamut of ITR-U BT.709. In addition, we have also developed an LSI that can deal with an extended color space xvYCC, which is a new international standard, and mounted the LSI in the HDTV. The display of colorful and natural video pictures has been achieved through the effective use of the wide color gamut involved in the laser light source supported by a video signal processing circuit that complies with the xvYCC standard and Natural Color Matrix, a color management technique.

4.3: Development of PTV Using Six-Primary-Color Display Technology

We have developed the 6 primary color PTV. Because of the newly developed 6-color color wheel, the 6-color light engine combined with the high-efficiency UHP lamp and our independent Plush1080p™ technology, the newly developed PTV ensures high brightness, a wide color gamut and high contrast.

70.3: Distinguished Contributed Paper: Wide Angle Projection Optics for Compact Rear Projector

We have developed a new projection optics with the exceptionally wide field angle of 160 degrees and the short projection distance of 125 mm with a 62 inch screen. It is constructed based on the Direct Projection Method which does not need a back mirror. In this paper, we will describe our new optical design concept and the characteristics of a prototype optical system.

3.4: Invited Paper: Laser TV - Ultra Wide Color Gamut in Conformity with xvYCC

This paper provides some interpretations of the Laser TV which we have successfully developed [1]. The Laser TV is an HDTV that adopts solid state lasers involving three primary colors, red, green and blue for the light source. The adoption of a laser light source helped us realize an HDTV with a dramatically wide color gamut, namely 190% the color gamut of ITU-R BT.709. In addition, we have also developed an LSI that can deal with the extended color space xvYCC, which is a new international standard, and mounted the LSI in the HDTV. The display of colorful and natural video pictures has been achieved through the effective use of the wide color gamut involved in the laser light source supported by a video signal processing circuit that complies with the xvYCC standard and Natural Color Matrix, a color management technique.

Projection optical system for a compact rear projector

— A new projection optical system with an exceptionally wide field angle of 160° and a short projection distance of 125 mm for a 62-in. screen has been developed. It is constructed based on the Direct Projection Method which does not require a back mirror. This paper presents a new optical design concept and the characteristics of a prototype optical system.

High-efficiency light-collection optics for lamp-based projection TV

— A new light-collection optics has been developed that enhances the luminance of projection TV which use lamps as the light source. The conventional optical system consists of an elliptical reflector and a flat-surface front glass, but these systems cannot sufficiently collect the beams coming from the light source, and they cause loss in the coupling with the light pipe. To solve this problem, we devised a new optical system through a structure of an aspherical reflector and an aspherical front glass. This new optical system concentrates the beams coming from the light source to a smaller point which improves the coupling efficiency. Thus, we have successfully increased the luminance of the projection TV by approximately 10%. This paper reports the design principles of the new optical system and the results of a prototype experiment.

Étendue-density homogenization lens optimized for high-pressure mercury lamps

— In order to increase the screen brightness of Digital Micromirror Device™ projectors (DMD™), we have developed a new aspherical lens. Homogenizing the etendue-density distribution made by a high-pressure mercury lamp, this lens improves the light convergence at its focal point where the rod integrators entrance is placed. Our simulation showed that the percentage of increase in brightness is up to 18.4%.

P‐203: Lens‐shiftable DLP™ Projector using Nontelecentric System

We have developed a lens-shiftable front projector of DLP™ system adopting a nontelecentric system that uses no prisms. The f-number of projection lens was composed smaller than the f-number of illumination optical system, and that, a fixed aperture was provided on the incidence side of the projection lens. This arrangement allowed us to realize a bright and high-contrast optical system with a compact structure.