Laser illuminating device and image display device
First Claim
1. A laser illuminating device comprising:
- a laser light source;
a first lens including a plurality of microlenses, each microlens of the plurality of microlenses having a predetermined numerical aperture in an in-plane direction, and each microlens of the plurality of microlenses being adapted to expand laser light emitted from the laser light source to thereby superimpose the laser light transmitted through each microlens of the plurality of microlenses; and
a second lens having an effective diameter larger than an effective diameter of the first lens, and for compensating for a divergence angle of the laser light expanded by each microlens of the plurality of microlenses,wherein the laser light source emits a plurality of the laser light, such that each laser light emitted from the laser light source has a wavelength that is different from wavelengths of other laser lights emitted from the laser light source, andwherein the laser illuminating device satisfies relations expressed by formulas (1) through (5);
d>
10×
(λ
l−
λ
s)
(1);
d<
R1/3
(2);
L−
R1/NAm<
BF2<
L+R1/NAm
(3);
R2>
2×
R1
(4); and
R2<
4×
L×
NAm
(5),where λ
1 is a longest wavelength to be used in the laser light source, λ
s is a shortest wavelength to be used in the laser light source, R1 is the effective diameter of the first lens, d is a minimum pitch of each microlens of the plurality of microlenses, L is a distance between the first lens and the second lens, R2 is the effective diameter of the second lens, BF2 is a back focus distance of the second lens, and NAm is a numerical aperture of each microlens of the plurality of microlenses.
1 Assignment
0 Petitions
Accused Products
Abstract
A laser illuminating device and an image display device are provided to enable a removal of speckle noises in a diffraction field and an image field, to uniformly illuminate an illumination plane, and to realize miniaturization. The laser illuminating device 100 includes a laser light source 3 and a first lens 1 including a plurality of microlenses 10, each having a predetermined numerical aperture in an in-plane direction, and each of the microlenses 10 being adapted to expand laser light emitted from the laser light source 3 to thereby superimpose the laser light transmitted through each of the microlenses 10. The laser illuminating device 100 also includes a second lens 2 having an effective diameter larger than an effective diameter of the first lens 1, and compensating for a divergence angle of the laser light expanded by each of the plurality of the microlenses 10.
34 Citations
16 Claims
-
1. A laser illuminating device comprising:
-
a laser light source; a first lens including a plurality of microlenses, each microlens of the plurality of microlenses having a predetermined numerical aperture in an in-plane direction, and each microlens of the plurality of microlenses being adapted to expand laser light emitted from the laser light source to thereby superimpose the laser light transmitted through each microlens of the plurality of microlenses; and a second lens having an effective diameter larger than an effective diameter of the first lens, and for compensating for a divergence angle of the laser light expanded by each microlens of the plurality of microlenses, wherein the laser light source emits a plurality of the laser light, such that each laser light emitted from the laser light source has a wavelength that is different from wavelengths of other laser lights emitted from the laser light source, and wherein the laser illuminating device satisfies relations expressed by formulas (1) through (5);
d>
10×
(λ
l−
λ
s)
(1);
d<
R1/3
(2);
L−
R1/NAm<
BF2<
L+R1/NAm
(3);
R2>
2×
R1
(4); and
R2<
4×
L×
NAm
(5),where λ
1 is a longest wavelength to be used in the laser light source, λ
s is a shortest wavelength to be used in the laser light source, R1 is the effective diameter of the first lens, d is a minimum pitch of each microlens of the plurality of microlenses, L is a distance between the first lens and the second lens, R2 is the effective diameter of the second lens, BF2 is a back focus distance of the second lens, and NAm is a numerical aperture of each microlens of the plurality of microlenses. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
Specification