Illumination device
AssigneeNippon Sheet Glass Co., Ltd.
InventorsKeiji Tsunetomo, Satoru Kusaka
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Abstract
Provided is a illumination device having a sufficiently wide irradiation angle and a uniform light intensity within a predetermined range even when using a light source that emits light similar to light with a small spread angle, such as a laser, or to parallel light. This illumination device includes a light source including at least one light emitting portion; a first optical element that receives light output from the light source and outputs the light while expanding an output angle thereof and a second optical element that receives light output from the first optical element and outputs the light while further expanding an irradiation angle thereof.
Claims8
An illumination device, comprising:
- a light source including at least one light emitting portion;
- a first optical element configured to receive light output from the light source and output the light while expanding an output angle thereof;
- and
- a second optical element configured to receive light output from the first optical element and output the light while further expanding an irradiation angle thereof;
- wherein the first optical element is a microlenses array;
- wherein the microlenses array includes a first region including a center C of the first optical element and a second region around the first region;
- and
- wherein the first region includes a plurality of microlenses having a substantially constant sag, and the second region includes a plurality of microlenses whose sag decreases as the distance from the center of the first optical element increases.
Dependencies are inferred from the claim text.