Kuniko Kojima

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.

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.

P-183: Development of a High-Brightness Dual-Lamp Projector

A projector has been developed that can display distinct pictures even in bright, spacious places. Two lamps are provided in a unique optical system to assure the brightness of 7,000 lumens and the high contrast ratio of 2,000 to 1, which are both the highest in their class [1].

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.

Brightness property of micro-capsules diffuser screen in laser projection display

In recent years, the development of displays, projectors, and the like which use laser light sources have been advanced. As a laser light source is used, it provide wide color gamut and compact an optical system; on the other hand, the speckle noise is generated. We make a proposal about the microcapsule diffuser screen with the purpose of reducing the speckle noise on a laser rear projection display. This microcapsule diffuser screen has a screen surface in which microcapsules (~100um) containing charged diffuser particles are applied; where an electric field is charged from the outside and, thus, the diffuser particles in the capsule are randomly agitated to reduce the speckle noise. We have separately reported the effect of reducing speckle in relation to the driving parameters. The previous report, however, did not discuss how the configuration parameters within the microcapsule would affect the brightness, diffusion characteristics and other particulars. In this report, the authors used the Monte Carlo ray tracing method to study the diffusion characteristics of the microcapsule diffuser sheet with reference to the refractive index and diameters of the diffuser particles. The study confirmed that while the diffusion characteristics lowered with the diffuser particle diameter being 3.0μm or smaller the optical loss of the transmitting light significantly increased. Where designing the capsule profile based on the simulation model, a simple spherical profile failed to see that the actual measurement and calculated values did not agree with the other. The optical simulation model created based on a microscopic image confirmed that both values agreed. Thus, the authors confirmed that the latter was suitable for an optical simulation model.