ILLUMINATION SYSTEM AND PROJECTION APPARATUS USING THE SAME

• US 20180157050A1
• Filed: 11/30/2017
• Published: 06/07/2018
• Est. Priority Date: 12/02/2016
• Status: Active Grant

• Current Assignee: Coretronic Corporation
• Original Assignee: Coretronic Corporation
• Inventors: Liao, Chien-Chung, Chang, Jui
• Granted Patent: US 10,429,658 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 27/10 Beam splitting or combining systems polarising systems G02B27/28; mixing and splitting light signals using optical waveguides G02B6/28; beam shaping, e.g. changing the cross-sectional area, by dividing or superposing multiple light beams G02B27/0905
• CPC Class Codes: G02B 27/1006 for splitting or combining different wavelengths G02B27/1086, G02B27/141 take precedence
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G03B 21/204 using secondary light emission, e.g. luminescence or fluorescence using different colours G03B33/00; if related to video signals H04N9/3197
• CPC Class Codes: G03B 21/2066 Reflectors in illumination beam in projection beam G03B21/28
• CPC Class Codes: H04N 9/3158 for controlling the spectrum
• CPC Class Codes: H04N 9/3164 using multiple light sources

Abstract

An illumination system includes a first light source providing a first color beam, a first beam-splitting element which disposes on a transmission path of the first color beam and separates the first color beam into a first sub-beam and a second sub-beam, an optical wavelength conversion element which receives the first sub-beam and converts the first sub-beam into a second color beam and reflects the second color beam back to the first beam-splitting element, a second light source providing a third color beam, and a second beam-splitting element which is located between the second light source and the first beam-splitting element to reflect the second sub-beam. The third color beam passes through the second beam-splitting element and is transmitted to the first beam-splitting element. The second sub-beam, the second color beam and the third color beam are combined into an illumination beam.

Claims

1. An illumination system, comprising:

a first light source, wherein the first light source is a laser light source and adapted to provide a first color beam;

a first beam-splitting element, disposed on a transmission path of the first color beam and used to separate the first color beam into a first sub-beam and a second sub-beam;

an optical wavelength converting element, disposed on a transmission path of the first sub-beam and used to convert the first sub-beam into a second color beam and reflect the second color beam back to the first beam-splitting element;

a second light source, adapted to provide a third color beam, and

a second beam-splitting element, disposed on a transmission path of the second sub-beam and located between the second light source and the first beam-splitting element, wherein the second sub-beam is reflected back to the first beam-splitting element by the second beam-splitting element, wherein the third color beam passes through the second beam-splitting element and is transmitted to the first beam-splitting element, wherein the second sub-beam, the second color beam and the third color beam are combined into an illumination beam by the first beam-splitting element.

2. The illumination system according to claim 1, wherein a first portion of the first color beam passes through the first beam-splitting element to form the first sub-beam transmitted to the optical wavelength conversion element, a second portion of the first color beam is reflected by the first beam-splitting element to form the second sub-beam transmitted to the second beam-splitting element, a first portion of the second sub-beam reflected back to the first beam-splitting element by the second beam-splitting element passes through the first beam-splitting element, the third color beam passes through the first beam-splitting element, wherein the second color beam reflected by the first beam-splitting element, the third beam passing through the first beam-splitting element and the first portion of the second sub-beam passing through the first beam-splitting element are combined into the illumination beam.

3. The illumination system according to claim 2, wherein the first beam-splitting element comprises:

a substrate;

a first beam-splitting layer, disposed on the substrate, and the first beam-splitting layer used to reflect the second portion of the first color beam to form the second sub-beam and allow the third color beam to pass therethrough; and

a second beam-splitting layer, disposed on the substrate, and the second beam-splitting layer used to allow the first portion of the first color beam to pass therethrough to form the first sub-beam, reflect the second color beam, and allow the second sub-beam and the third color beam transmitted from the second beam-splitting element to pass therethrough, wherein a coverage area of the first beam-splitting layer on the substrate is smaller than a coverage area of the second beam-splitting layer on the substrate.

4. The illumination system according to claim 3, wherein the coverage area of the first beam-splitting layer on the substrate is 5% to 20% of the coverage area of the second beam-splitting layer on the substrate.

5. The illumination system according to claim 2, wherein the first beam-splitting element comprises:

a substrate, having a first surface and a second surface opposite to the first surface;

a first beam-splitting layer, disposed on the first surface and located between the substrate and the first light source, wherein the first beam-splitting layer is used to allow the first portion of the first color beam to pass therethrough to form the first sub-beam and reflect the second portion of the first color beam to form the second sub-beam; and

a second beam-splitting layer, disposed on the second surface, and the second beam-splitting layer used to allow the first sub-beam and the third color beam to pass therethrough and reflect the second color beam.

6. The illumination system according to claim 5, wherein a reflectance and a transmittance of the first beam-splitting layer to the first color beam are X % and Y % respectively, wherein X is between 10-30, Y is between 90-70, and X+Y is smaller than or equal to 100.

7. The illumination system according to claim 1, wherein a first portion of the first color beam is reflected by the first beam-splitting element to form the first sub-beam transmitted to the optical wavelength conversion element, a second portion of the first color beam passes through the first beam-splitting element to form the second sub-beam transmitted to the second beam-splitting element, a first portion of the second sub-beam reflected back to the first beam-splitting element by the second beam-splitting element is reflected by the first beam-splitting element, and the third color beam is reflected by the first beam-splitting element, wherein the second color beam passing through the first beam-splitting element, the third color beam reflected by the first beam-splitting element and the first portion of the second sub-beam reflected by the first beam-splitting element are combined into the illumination beam.

8. The illumination system according to claim 7, wherein the first beam-splitting element comprises:

a substrate, comprising a through-hole, wherein the through-hole is used to allow the second portion of the first color beam to pass therethrough to form the second sub-beam;

a first beam-splitting layer, disposed on the substrate and used to reflect the first portion of the first color beam to form the first sub-beam and allow the second color beam to pass therethrough; and

a second beam-splitting layer, disposed on the substrate, and the second beam-splitting layer used to allow the second color beam to pass therethrough and reflect the third color beam and the second sub-beam reflected by the second beam-splitting element, wherein an area of the through-hole in the substrate is smaller than a coverage area of the first or second beam-splitting layer on the substrate.

9. The illumination system according to claim 8, wherein an area of the through-hole in the substrate is 5%-20% of a coverage area of the first or second beam-splitting layer on the substrate.

10. The light source module according to claim 7, wherein the first beam-splitting element comprises:

a substrate, having a first surface and a second surface opposite to the first surface;

a first beam-splitting layer, disposed on first surface and located between the substrate and the first light source, wherein the first beam-splitting layer is used to reflect the first portion of the first color beam to form the first sub-beam and allow the second portion of the first color beam to pass therethrough to form the second sub-beam; and

a second beam-splitting layer, disposed on the second surface, and the second beam-splitting layer used to allow the second sub-beam and the second color beam to pass therethrough and reflect the third color beam.

11. The illumination system according to claim 10, wherein a reflectance and a transmittance of the first beam-splitting layer to the first color beam are X % and Y % respectively, wherein X is between 90-70, Y is between 10-30, and X+Y is smaller than or equal to 100.

12. The illumination system according to claim 1, wherein the second beam-splitting element comprises:

a diffusion layer; and

a third beam-splitting layer,

wherein the diffusion layer is located between the third beam-splitting layer and the first beam-splitting element, the second sub-beam passes through the diffusion layer and then is reflected back to the first beam-splitting element by the third beam-splitting layer, and the third color beam sequentially passes through the third beam-splitting layer and the diffusion layer and is transmitted to the first beam-splitting element.

13. The illumination system according to claim 1, wherein the first color beam is a blue beam, the second color beam is a yellow beam or a green beam, and the third color beam is a red beam.

14. The illumination system of claim 1, wherein the optical wavelength conversion element is a phosphor color wheel.

15. The illumination system according to claim 12, wherein the second beam-splitting element further comprises a moving member, the diffusion layer is connected to the moving member, the third beam-splitting layer is disposed on a surface of the diffusion layer facing the second light source, and the moving member is adapted to rotate or vibrate.

16. The illumination system of claim 1, wherein the second light source is a light emitting diode light source or a laser light source.

17. The illumination system according to claim 1, further comprising a light integration rod disposed on a transmission path of the illumination beam.

18. A projection apparatus, comprising:

the illumination system claimed in claim 1;

a beam-splitting and combiner system, disposed on a transmission path of the illumination beam provided by the illumination system and used to separate the illumination beam into a fourth color beam, a fifth color beam and a sixth color beam;

a first light valve, disposed on a transmission path of the fourth color beam and used to convert the fourth color beam into a first sub-image beam;

a second light valve, disposed on a transmission path of the fifth color beam and used to convert the fifth color beam into a second sub-image beam;

a third light valve, disposed on a transmission path of the sixth color beam and used to convert the sixth color beam into a third sub-image beam, wherein the first sub-image beam, the second sub-image beam and the third sub-image beam are combined into an image beam by the beam-splitting and combiner system; and

a projection lens, disposed on a transmission path of the combined image beam and used to project the combined image beam.

19. A projection apparatus, comprising:

the illumination system claimed in claim 1;

a light valve, disposed on a transmission path of the illumination beam provided by the illumination system and used to convert the illumination beam into an image beam; and

a projection lens, disposed on a transmission path of the image beam and used to project the image beam.