Illumination module and display device

Patent metadata

Field	Value
Publication number	US-9829714-B2
Application number	US-201514798968-A
Country	US
Kind code	B2
Filing date	Jul 14, 2015
Priority date	Jan 6, 2015
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

An illumination module for a display device is disclosed. The illumination module has a principal optical axis. The illumination module includes a light source, an image unit, a beam splitting unit, a first relaying unit and a second relaying unit. The beam splitting unit has a transmitting surface, a first reflective surface and a second reflective surface. The first reflective surface and the second reflective surface are disposed correspondingly to each other. The light source provides light to pass through the image unit and the beam splitting unit in sequence, one portion of the light forms a first light beam, one portion of the light forms a second light beam. The optical axes of the first and second light beams each has an offset with respect to the principal optical axis, and the first offset and the second offset have equivalent scalars and opposite offset directions.

First claim

What is claimed is:

1. An illumination module for a display device, wherein the illumination module has a principal optical axis, comprising:
a light source providing a light;
an image unit;
a beam splitting unit having a transmitting surface, a first reflective surface and a second reflective surface, wherein the first reflective surface and the second reflective surface are disposed correspondingly to each other;
a first relaying unit; and
a second relaying unit;
wherein the light passes through the image unit and the beam splitting unit in sequence, one portion of the light forms a first light beam, one portion of the light forms a second light beam, the first light beam is reflected into the first relaying unit by the first reflective surface, the first relaying unit transmits the first light beam to the beam splitting unit, and the first light beam passes through and exits from the beam splitting unit,
wherein the second light beam passes through the beam splitting unit and enters the second relaying unit, the second relaying unit transmits the second light beam to the second reflective surface of the beam splitting unit, and the second light beam is reflected by the second reflective surface and exits from the beam splitting unit,
wherein a first offset exists between a first optical axis of the first light beam and the principal optical axis, a second offset exists between a second optical axis of the second light beam and the principal optical axis, and the first offset and the second offset have equivalent scalars and opposite offset directions.

2. The illumination module of claim 1 , wherein the illumination module has an aperture, and the scalars of the first offset and the second offset are equal to the quarter of the aperture.

3. The illumination module of claim 1 , wherein the image unit is a digital micromirror device or a LCD device, and the light source is a laser light source or a laser array.

4. The illumination module of claim 1 , further comprising a polarizing unit, wherein after exiting from the image unit, the light enters the polarizing unit to form horizontally polarized light or vertically polarized light.

5. The illumination module of claim 1 , wherein the first relaying unit has a first polarizing element, the first polarizing element has a black stripe mask, a plurality of stripe quarter-wave plates and a reflector, the stripe quarter-wave plates are disposed on the reflector, and the black stripe mask is disposed orthogonally on the stripe quarter-wave plates.

6. The illumination module of claim 1 , wherein the first relaying unit has a first polarizing element, the first polarizing element has a black stripe mask, a quarter-wave plate and a reflector, the quarter-wave plate is disposed on the reflector, and the black stripe mask is disposed on the quarter-wave plate.

7. The illumination module of claim 1 , further comprising an optical scan element, wherein the light is transmitted to the image unit by the optical scan element, and the optical scan element drives a reflective surface of the optical scan element to deflect according to different time sequences to form a plurality of different images.

8. The illumination module of claim 7 , wherein the optical scan element is a voice coil motor, polygon mirror or MEMS (microelectromechanical systems) lens.

9. The illumination module of claim 1 , wherein the beam splitting unit further comprises a first prism, a second prism and a third prism, the first prism forms the transmitting surface, the second prism and the third prism are disposed on the transmitting surface of the first prism, the first reflective surface is disposed on one side of the second prism opposite the third prism, and the second reflective surface is disposed on one side of the third prism opposite the second prism.

10. A display device, comprising:
a display screen;
an illumination module having a principal optical axis, comprising:
a light source providing a light;
an image unit;
a beam splitting unit having a transmitting surface, a first reflective surface and a second reflective surface, wherein the first reflective surface and the second reflective surface are disposed correspondingly to each other;
a first relaying unit; and
a second relaying unit;

wherein the light passes through the image unit and the beam splitting unit in sequence, one portion of the light forms a first light beam, one portion of the light forms a second light beam, the first light beam is reflected into the first relaying unit by the first reflective surface, and the first relaying unit transmits the first light beam to the beam splitting unit,
wherein the second light beam passes through the beam splitting unit and enters the second relaying unit, the second relaying unit transmits the second light beam to the second reflective surface of the beam splitting unit, and the second light beam is reflected by the second reflective surface and exits from the beam splitting unit,
wherein a first offset exists between a first optical axis of the first light beam and the principal optical axis, a second offset exists between a second optical axis of the second light beam and the principal optical axis, the first offset and the second offset have equivalent scalars, and the first light beam and the second light beam are transmitted to the display screen by the beam splitting unit.

11. The display device of claim 10 , wherein the illumination module has an aperture, and the scalars of the first offset and the second offset are equal to the quarter of the aperture.

12. The display device of claim 10 , wherein the image unit is a digital micromirror device or a LCD device, and the light source is a laser light source or a laser array.

13. The display device claim 10 , wherein the illumination module further comprises a polarizing unit, wherein after exiting from the image unit, the light enters the polarizing unit to form horizontally polarized light or vertically polarized light.

14. The display device of claim 10 , wherein the first relaying unit of the illumination module has a first polarizing element, the first polarizing element has a black stripe mask, a plurality of stripe quarter-wave plates and a reflector, the stripe quarter-wave plates are disposed on the reflector, and the black stripe mask is disposed orthogonally on the stripe quarter-wave plates.

15. The display device of claim 10 , wherein the first relaying unit of the illumination module has a first polarizing element, the first polarizing element has a black stripe mask, a quarter-wave plate and a reflector, the quarter-wave plate is disposed on the reflector, and the black stripe mask is disposed on the quarter-wave plate.

16. The display device of claim 10 , wherein the illumination module further comprises an optical scan element, wherein the light is transmitted to the image unit by the optical scan element, and the optical scan element deflects according to different time sequences to form a plurality of different images.

17. The display device of claim 10 , wherein the beam splitting unit further comprises a first prism, a second prism and a third prism, the first prism forms the transmitting surface, the second prism and the third prism are disposed on the transmitting surface of the first prism, the first reflective surface is disposed on one side of the second prism opposite the third prism, and the second reflective surface is disposed on one side of the third prism opposite the second prism.

18. The display device of claim 10 , wherein the display scre

Assignees

• Delta Electronics Inc

Inventors

• Huang June-Jei

Classifications

• G02B30/35 Primary

  using reflective optical elements in the optical path between the images and the observer · CPC title

• G02B27/286

  for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another (G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34) · CPC title

• G02B27/1066 Primary

  for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view · CPC title

• G02B27/149

  using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes · CPC title

• G02B27/2235 Primary

  Physics · mapped topic