Abstract: An external-control-type fan coupling device is provided and has no restriction on the layout or positional relationship of an electromagnetic coil and a valve element of the device. As a result, the casing and the valve structure of the device can be simplified. Additionally, the design prevents leaking of oil and leaking of magnetism without adversely affecting performance.

Abstract: An external-control-type fan coupling device is provided and has no restriction on the layout or positional relationship of an electromagnetic coil and a valve element of the device. As a result, the casing and the valve structure of the device can be simplified. Additionally, the design prevents leaking of oil and leaking of magnetism without adversely affecting performance.

Abstract: An external-control-type fan coupling device is provided and has no restriction on the layout or positional relationship of an electromagnetic coil and a valve element of the device. As a result, the casing and the valve structure of the device can be simplified. Additionally, the design prevents leaking of oil and leaking of magnetism without adversely affecting performance.

Abstract: An external-control-type fan coupling device is provided and has no restriction on the layout or positional relationship of an electromagnetic coil and a valve element of the device. As a result, the casing and the valve structure of the device can be simplified. Additionally, the design prevents leaking of oil and leaking of magnetism without adversely affecting performance.

Abstract: An external-control-type fan coupling device is provided and has no restriction on the layout or positional relationship of an electromagnetic coil and a valve element of the device. As a result, the casing and the valve structure of the device can be simplified. Additionally, the design prevents leaking of oil and leaking of magnetism without adversely affecting performance.

Abstract: An external-control-type fan coupling device is provided and has no restriction on the layout or positional relationship of an electromagnetic coil and a valve element of the device. As a result, the casing and the valve structure of the device can be simplified. Additionally, the design prevents leaking of oil and leaking of magnetism without adversely affecting performance.

Abstract: A projection type display apparatus comprising a light source apparatus which is provided with an elliptic mirror 12, a light source 11 disposed at the first focal point, a cone-like material disposed at the second focal point, a condenser lens 13, display elements 15R-15B, a color separating and synthesizing optical system, second condenser lenses 16R-16B and a projection lens 19. The cone-like material is one selected from the group of a convex cone lens, a concave cone lens 2, a convex cone-like reflector and a concave cone-like reflector 20. In the projection type display element, light emitted from the light source is introduced into the cone-like material and is emitted as divergent light through the conical surface of the cone-like material.

Abstract: A light source optical system for projection 1, dichroic mirrors 21, 22 disposed to have a predetermined included angle .beta., a reflection type liquid crystal optical element blocks 31-33 each including a closely contacted converging lens and having a reflection surface and a projection optical system 4 are provided, wherein the normal line of a dichroic mirror surface and the optical axis of incident light form an included angle .alpha.; the normal line of the reflection surface and the optical axis of incident light form an included angle .gamma.; light emitted from a light source is color-separated so as to become color lights; the color lights are rendered to be parallel light beams, and are modulated and reflected by means of the reflection type liquid crystal optical elements; the reflected light beams are color-synthesized; and the color-synthesized light is projected through a projection lens.

Abstract: A projection type display apparatus comprising a light source apparatus which is provided with an elliptic mirror 12, a light source 11 disposed at the first focal point, a cone-like material disposed at the second focal point, a condenser lens 13, display elements 15R-15B, a color separating and synthesizing optical system, second condenser lenses 16R-16B and a projection lens 19. The cone-like material is one selected from the group of a convex cone lens, a concave cone lens 2, a convex cone-like reflector and a concave cone-like reflector 20. In the projection type display element, light emitted from the light source is introduced into the cone-like material and is emitted as divergent light through the conical surface of the cone-like material.

Abstract: A light source optical system for projection 1, dichroic mirrors 21, 22 disposed to have a predetermined included angle .beta., a reflection type liquid crystal optical element blocks 31-33 each including a closely contacted converging lens and having a reflection surface and a projection optical system 4 are provided, wherein the normal line of a dichroic mirror surface and the optical axis of incident light form an included angle .alpha.; the normal line of the reflection surface and the optical axis of incident light form an included angle .gamma.; light emitted from a light source is color-separated so as to become color lights; the color lights are rendered to be parallel light beams, and are modulated and reflected by means of the reflection type liquid crystal optical elements; the reflected light beams are color-synthesized; and the color-synthesized light is projected through a projection lens.