Fresnel optical element and projection display apparatus

A Fresnel optical element having a plurality of Fresnel prisms arranged on a surface of a base faced a light emitting body,

• each of said plurality of Fresnel prisms having a first surface for receiving a part of an incident light ray emitted from a light emitting body, a second surface faced the first surface each other, and a third surface placed between the first surface and the second surface,
• wherein the second surface receives at least a part of the incident light ray passing through the first surface, and
• wherein the third surface is transparent, and has an optical diffusing function of diffusing an incident light ray.

A Fresnel optical element having a plurality of Fresnel prisms arranged on a surface of a base faced a light emitting body,

• each of said plurality of Fresnel prisms having a first surface for receiving a part of an incident light ray emitted from said light emitting body, a second surface faced the first surface each other, and a third surface placed between the first surface and the second surface,
• wherein the second surface receives at least a part of the incident light ray passing through the first surface, and
• wherein the third surface is transparent and has an optical absorbing function of absorbing an incident light ray.

A Fresnel optical element having a plurality of Fresnel prisms arranged on a surface of a base faced a light emitting body,

• each of said plurality of Fresnel prisms having a first surface for receiving a part of an incident light ray emitted from a light emitting body, a second surface faced the first surface each other, and a third surface placed between the first surface and the second surface,
• wherein the second surface reflects at least a part of the incident light ray passing through the first surface to the surface of the base, and
• wherein the third surface is transparent, and has an optical diffusing function of diffusing an incident light ray.

A Fresnel optical element having a plurality of Fresnel prisms arranged on a surface of a base faced a light emitting body,

• each of said plurality of Fresnel prisms having a first surface for receiving a part of an incident light ray emitted from a light emitting body, a second surface faced the first surface each other, and a third surface placed between the first surface and the second surface,
• wherein the second surface reflects at least a part of the incident light ray passing through the first surface to the surface of the base, and
• wherein the third surface is transparent, and has an optical absorbing function of absorbing an incident light ray.

A Fresnel optical element having a plurality of Fresnel prisms arranged on a surface of a base faced a light emitting body,

• each of said plurality of Fresnel prisms having a first surface for receiving a part of an incident light ray emitted from said light emitting body, a second surface faced the first surface each other, and a third surface placed between the first surface and the second surface,
• wherein the third surface has an optical diffusing function of diffusing an incident light ray.