Head-mounted display device
There is provided in the present disclosure a head-mounted display device, including: a first positive lens, a second positive lens and a micro-display component arranged coaxially and sequentially, where a light incident surface of the first positive lens is close to a light emergent surface of the second positive lens, and a light incident surface of the second positive lens is close to the micro-display component; the light emergent surface of the second positive lens is a convex Fresnel surface, and the light incident surface of the first positive lens is a planar Fresnel surface. The head-mounted display device provided by the present disclosure can effectively enlarge the field angle and reduce the volume.
1. A head-mounted display device, comprising: a first positive lens, a second positive lens and a micro-display component arranged coaxially and sequentially, wherein a light incident surface of the first positive lens is close to a light emergent surface of the second positive lens, and a light incident surface of the second positive lens is close to the micro-display component; and the light emergent surface of the second positive lens is a convex Fresnel surface, and the light incident surface of the first positive lens is a planar Fresnel surface.
2. The device of claim 1 , wherein a light emergent surface of the first positive lens is a planar diffractive surface.
3. The device of claim 1 , wherein the light incident surface of the second positive lens is a concave aspheric surface.
4. The device of claim 1 , wherein a distance TTL from a center point of a display screen of the micro-display component to a center point of the light emergent surface of the first positive lens is less than 18 mm.
5. The device of claim 4 , wherein:
a distance T 0 from a center point of the first positive lens to human eyes satisfies a condition of 0.7 TTL<T 0 <0.8 TTL; and
a center thickness T 1 of the first positive lens satisfies a condition of 0.1 TTL<T 1 <0.2 TTL.
6. The device of claim 4 , wherein a center thickness T 2 of the second positive lens satisfies a condition of 0.2 TTL<T 2 <0.3 TTL.
7. The device of claim 4 , wherein a focal length F of the device satisfies a condition of 0.8 TTL<F<0.9 TTL.
8. The device of claim 7 , wherein a Fresnel curvature radius R of the light incident surface of the first positive lens satisfies a condition of −2 F<R<−F.
9. The device of claim 7 , wherein the first positive lens has a focal length F1 smaller than 2 F, and the second positive lens has a focal length F2 greater than 2 F.
10. The device of claim 1 , wherein:
a refractive index n 1 and a dispersion v 1 of the first positive lens satisfy a condition of 1.5<n 1 <1.55 and 55<v 1 <60; and
a refractive index n 2 and a dispersion v 2 of the second positive lens satisfy a condition of 1.5<n 2 <1.55 and 55<v 2 <60.
11. The device of claim 2 , wherein:
a refractive index n 1 and a dispersion v 1 of the first positive lens satisfy a condition of 1.5<n 1 <1.55 and 55<v 1 <60; and
a refractive index n 2 and a dispersion v 2 of the second positive lens satisfy a condition of 1.5<n 2 <1.55 and 55<v 2 <60.
12. The device of claim 3 , wherein:
a refractive index n 1 and a dispersion v 1 of the first positive lens satisfy a condition of 1.5<n 1 <1.55 and 55<v 1 <60; and
a refractive index n 2 and a dispersion v 2 of the second positive lens satisfy a condition of 1.5<n 2 <1.55 and 55<v 2 <60.
13. The device of claim 4 , wherein:
a refractive index n 1 and a dispersion v 1 of the first positive lens satisfy a condition of 1.5<n 1 <1.55 and 55<v 1 <60; and
a refractive index n 2 and a dispersion v 2 of the second positive lens satisfy a condition of 1.5<n 2 <1.55 and 55<v 2 <60.
14. The device of claim 5 , wherein:
a refractive index n 1 and a dispersion v 1 of the first positive lens satisfy a condition of 1.5<n 1 <1.55 and 55<v 1 <60; and
a refractive index n 2 and a dispersion v 2 of the second positive lens satisfy a condition of 1.5<n 2 <1.55 and 55<v 2 <60.
15. The device of claim 6 , wherein:
a refractive index n 1 and a dispersion v 1 of the first positive lens satisfy a condition of 1.5<n 1 <1.55 and 55<v 1 <60; and
a refractive index n 2 and a dispersion v 2 of the second positive lens satisfy a condition of 1.5<n 2 <1.55 and 55<v 2 <60.
16. The device of claim 7 , wherein:
a refractive index n 1 and a dispersion v 1 of the first positive lens satisfy a condition of 1.5<n 1 <1.55 and 55<v 1 <60; and
a refractive index n 2 and a dispersion v 2 of the second positive lens satisfy a condition of 1.5<n 2 <1.55 and 55<v 2 <60.
17. The device of claim 8 , wherein:
a refractive index n 1 and a dispersion v 1 of the first positive lens satisfy a condition of 1.5<n 1 <1.55 and 55<v 1 <60; and
a refractive index n 2 and a dispersion v 2 of the second positive lens satisfy a condition of 1.5<n 2 <1.55 and 55<v 2 <60.
18. The device of claim 2 , wherein at least two slits are etched on the planar diffractive surface, and a width of each slit is 1-2 μm.
19. The device of claim 3 , wherein a curvature radius of the concave aspheric surface continuously changes from a center of the concave aspheric surface to an edge of the concave aspheric surface.
20. The device of claim 3 , wherein the concave aspheric surface has a varying curvature radius.