Illumination optical system and projection display optical system
AssigneeCanon Kabushiki Kaisha
InventorJun Koide
Life of this patent
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Abstract
An illumination optical system which can use light from a light source with high efficiency and can provide an illumination luminous flux with highly uniform illuminance, is disclosed. The illumination optical system illuminates an illumination surface with a generally telecentric illumination luminous flux. In light intensity distribution of illumination light on the illumination surface changing depending on a deviation angle of an incident ray with respect to a normal to the illumination surface, the illumination optical system operates the illumination luminous flux such that a ratio of angle widths at which light intensity reaches half of a peak value in each of two axis directions orthogonal to each other on the illumination surface is an aspect ratio of 2:1.
Claims22
An illumination optical system which illuminates an illumination surface with illumination luminous flux from a light source, comprising:
- a first optical system with an optical power in a first plane including a normal to the illumination surface, which guides the illumination luminous flux from the light source to the illumination surface,
- wherein the first optical system includes, an optical integrator which has a plurality of lenses with optical powers different between the first plane and a second plane including the normal and being orthogonal to the first plane, and a condenser lens with an optical power in the first plane, which guides the illumination luminous flux emitted from the optical integrator to the illumination surface,
- wherein light intensity distribution of the illumination luminous flux on the illumination surface represents a relationship between light intensity and incident angle to the illumination surface, and
- wherein, in the light intensity distribution, an incident angle width at which the light intensity reaches half of a peak value in the first plane is twice or more an incident angle width at which the light intensity reaches half of a peak value in the second plane.
An image display apparatus comprising:
- at least one image display element;
- an illumination optical system which illuminates the image display element with light from a light source;
- and
- a projection optical system which projects an image light from the image display element,
- wherein the illumination optical system includes a first optical system with an optical power in a first plane including a normal to the illumination surface of the image display element, which guides light from the light source to the illumination surface,
- wherein the first optical system includes an optical integrator having a plurality of lenses with optical powers different between the first plane and a second plane including the normal and being orthogonal to the first plane, and a condenser lens with an optical power in the first plane, which guides the light emitted from the optical integrator to the illumination surface,
- wherein light intensity distribution on the illumination surface represents a relationship between light intensity and incident angle to the illumination surface, and
- wherein, in the light intensity distribution, an incident angle width at which the light intensity reaches half of a peak value in the first plane is twice or more an incident angle width at which the light intensity reaches half of a peak value in the second plane.
An image display apparatus comprising:
- at least one display element;
- an illumination optical system which illuminates the image display element with light from a light source;
- and
- a projection optical system which projects image light from the image display element;
- wherein the illumination optical system includes a first optical system with an optical power in a first plane including a normal to an illumination surface of the image display element, which guides light from the light source to the illumination surface, and an optical surface which is inclined with respect to the normal to the illumination surface and reflects at least one of light from the light source,
- wherein the first optical system includes an optical integrator which has a plurality of lenses with optical powers different between the first plane and a second plane including the normal and being orthogonal to the first plane, and a condenser lens with an optical power in the first plane, which guides light emitted from the optical integrator to the illumination surface,
- wherein light intensity distribution on the illumination surface represents a relationship between light intensity and incident angle to the illumination surface,
- wherein the incident angle width at which light intensity reaches half of peak value in the first plane is larger than the incident angle width at which light intensity reaches half of peak value in the second plane, and
- wherein the normal to the optical surface is parallel to the second plane and is not parallel to the first plane.
Dependencies are inferred from the claim text.