Laser display apparatus
View Patent ↗Provided is a laser display apparatus in which speckle can be suppressed. The laser display apparatus includes: a laser comprising a first mirror and a second mirror that are separated by a cavity distance and form a cavity; and a spatial modulator modulating light transmitted through the first mirror of the laser to display an image on a screen, wherein, when a coherence length l c and an effective reflectivity R are defined by the following equation: l c = 2 d π R 1 / 2 1 - R R = R 1 × R 2 [ Equation ] where d is the cavity distance of the laser, R 1 is the reflectivity of the first mirror, and R 2 is the reflectivity of the second mirror, the coherence length l c satisfies the following inequality: 0< l c ≦0.85[cm].
1. A laser display apparatus comprising:
a laser comprising a first mirror and a second mirror that are separated by a cavity distance and form a cavity; and
a spatial modulator modulating light transmitted through the first mirror of the laser to display an image on a screen,
wherein, when a coherence length l c and an effective reflectivity R of the laser are defined by the following equation:
l
c
=
2
d
π
R
1
/
2
1
-
R
R
=
R
1
×
R
2
[
Equation
]
where d is the cavity distance of the laser, R 1 is the reflectivity of the first mirror, and R 2 is the reflectivity of the second mirror, the coherence length l c satisfies the following inequality:
0 <l c ≦0.85[cm].
2. The laser display apparatus of claim 1 , wherein the laser comprises a semiconductor laser.
3. The laser display apparatus of claim 2 , wherein the cavity distance d satisfies 100≦d≦5000 [μm].
4. The laser display apparatus of claim 1 , wherein the laser comprises a diode pumped solid state laser.
5. The laser display apparatus of claim 4 , wherein the cavity distance d satisfies 1≦d≦50 [mm].
6. The laser display apparatus of claim 1 , wherein the laser radiates visible light with a wavelength ranging from about 400 nm to about 700 nm.