Nikon Corporation

Kazufumi Ishibashi

Tetsuo Hattori

Masaaki Kusano

Kiyoshi Numazaki

Yasuhiro Iwaguchi

Shuichi Sugai

Tadaaki Nakamura

Motoi Ueda

Yoshiro Oikawa

A cross dichroic prism comprises four triangular prisms having isosceles right triangular cross sections identical in shape, opposing side faces thereof being bonded and secured together with rectangular portions thereof facing each other; and a dichroic film having an X-shaped cross section formed between the bonding faces of the triangular prisms; wherein, of the four triangular prisms, a given prism and at least one of the prisms adjacent thereto have a refractive index difference therebetween of 0.00005 or less, and the remaining two prisms opposed thereto have a refractive index difference therebetween of 0.00005 or less.

Cross dichroic prism, method of making the same, and full-color projector using the same

Cross dichroic prism, method of making the same, and full-color

The present invention relates to a projection type display apparatus which utilizes a polarizing beam splitter and/or a color separating/combining optical system, each being constituted by an optically transparent material block having a specific characteristic, thereby being capable of securing optically stable performances against influences of various thermal and external stresses and suppressing image quality deterioration to a low level. In particular, in this projection type display apparatus, the polarizing beam splitter used for a polarized light separating optical system and analyzing optical system, and/or an optical member servicing as a color separating/combining optical system are constituted by an optically transparent material block in which a wavelength where the absolute value of a photoelastic constant becomes a minimum level exists in a wavelength range of a blue light component.

Projection type display apparatus

In order to obtain an image without a registration shift, there is provided a color composing optical system which comprises a liquid crystal light valve having a plurality of pixels and a cross dichroic prism for color-composing the light beams emitted from the liquid crystal light valve, characterized in that the following equation is satisfied:

Color composing optical system

Growing community of inventors

Kanagawa, Japan

Kazufumi Ishibashi