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US 7,611,246 B2Granted
Projection display and optical integrator
AssigneeHitachi, Ltd.
InventorsNobuyuki Kimura, Kentaro Kato
Life of this patent
Estimating the term…
Abstract
A projection display makes it possible to minimize the costs of a polarization conversion element, and concurrently makes it possible to improve illuminance nonuniformity and optical utilization efficiency and to accomplish physical apparatus compactness. An optical integrator used in the projection display is configured such that, in comparison to the number of arrangements of polarization conversion units in a predetermined direction, a split number of an array lens in the same direction is greater.
Claims11
A projection display, comprising:
- a light source;
- an image display element that forms an optical image by using light emitted by the light source;
- a projection lens that performs magnified projection of the optical image;
- a polarization conversion element that emanates light which is incident on the image display element, as polarized light and that includes a plurality of units arranged in an even number of rows along a first direction to be symmetric with respect to a center axis;
- a first array lens including a plurality of first lens cells that are arranged along a direction substantially parallel to the polarization conversion element and that are arranged in the first direction in an odd number of rows which is greater than the number of rows of the plurality of units;
- and
- a second array lens including a plurality of second lens cells that are arranged in the first direction in an odd number of rows respectively in correspondence to the first lens cells of the first array lens,
- wherein a width of a second lens cell of a center row in the first direction is narrower than widths of second lens cells of other rows.
5 more elements
An optical integrator usable in a projection display, comprising:
- a first array lens including a plurality of first lens cells arranged in a first direction in an odd number of rows;
- and
- a second array lens including a plurality of second lens cells that are arranged in the first direction in an odd number of rows respectively in correspondence to the first lens cells of the first array lens, wherein a width of a second lens cell of a center row in the first direction is narrower than widths of second lens cells of other rows;
- wherein the plurality of first lens cells are arranged in the first direction in an odd number of columns;
- and
- wherein the plurality of second lens cells are arranged in the first direction in an odd number of columns, wherein a width of a second lens cell in a center column in the first direction is narrower than widths of other second lens cells.
3 more elements
A projection display, comprising:
- a light source;
- an image display element that forms an optical image by using light emitted by the light source;
- a projection lens that performs magnified projection of the optical image;
- a polarization conversion element that emanates light which is incident on the image display element, as polarized light and that includes a plurality of units arranged in an n columns (n =positive integer) along a first direction;
- a first array lens including a plurality of first lens cells that are arranged along a direction substantially parallel to the polarization conversion element and that are arranged in the first direction in at least an n+1 rows;
- and
- a second array lens including a plurality of second lens cells that are arranged in the first direction in at least n1 columns respectively in correspondence to the first lens cells of the first array lens, wherein light rays emanated from, a plurality of certain second lens cells adjacent to one another, of the second lens cells, are incident on one of the plurality of units.
4 more elements
Dependencies are inferred from the claim text.