Optical system and image protection apparatus
AssigneeCanon Kabushiki Kaisha
InventorJun Koide
Life of this patent
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Abstract
An optical system is disclosed which is capable of improving of its contrast characteristic and displaying of images which have a brightness according to the brightness of the use environment. The optical system comprises an optical integrator which divides and recombines the illumination luminous flux in a first axis direction and a light intensity distribution converter which converts the light intensity distribution of the illumination luminous flux in a second axis direction. The optical system further comprises a luminous flux limiting unit which has an aperture. The size of the aperture is changeable in the second axis direction and unchangeable in the first axis direction.
Claims27
An optical system which introduces an illumination luminous flux from a light source to an image-forming element and projects an luminous flux from the image-forming element onto a projection surface, the optical system comprising:
- an optical integrator which divides and recombines the illumination luminous flux in a first axis direction in a two-dimensional section that is orthogonal to a travelling direction of the illumination luminous flux;
- a light intensity distribution converter which has a function to convert the light intensity distribution of the illumination luminous flux in a second axis direction, which is orthogonal to the first axis direction, in the two-dimensional section;
- and
- a luminous flux limiting unit which has an aperture, the size of the aperture being changeable in the second axis direction and unchangeable in the first axis direction.
An optical system which introduces an illumination luminous flux from a light source to an image-forming element, the optical system comprising:
- an optical integrator which divides and recombines the illumination luminous flux in a first axis direction in a two-dimensional section that is orthogonal to a travelling direction of the illumination luminous flux;
- a light intensity distribution converter which has a function to convert the light intensity distribution of the illumination luminous flux in a second axis direction, which is orthogonal to the first axis direction, in the two-dimensional section;
- and
- a luminous flux limiting unit which has an aperture, the size of the aperture being changeable in the second axis direction and unchangeable in the first axis direction.
An optical system which introduces an illumination luminous flux from a light source to an image-forming element and projects an luminous flux from the image-forming element onto a projection surface, the optical system comprising:
- an optical integrator which divides and recombines the illumination luminous flux in a first axis direction in a two-dimensional section that is orthogonal to a travelling direction of the illumination luminous flux;
- a light intensity distribution converter which has at least a function to convert the light intensity distribution of the illumination luminous flux in a second axis direction, which is orthogonal to the first axis direction, in the two-dimensional section;
- and
- a luminous flux limiting unit which has an aperture,
- wherein the luminous flux limiting unit has a part where the width of the aperture in the second axis direction becomes larger as the distance from an optical axis of the optical system increases in the first axis direction.
Dependencies are inferred from the claim text.