Illumination device and image projection apparatus including the same

• US 6,318,863 B1
• Filed: 09/10/1999
• Issued: 11/20/2001
• Est. Priority Date: 01/21/1999
• Status: Expired due to Term

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Tiao, Kuo-Tung, Chuang, Fu-Ming, Yoo, Jinn-Chou, Chan, Sheng-Hsiung, Shiau, Tzeng-Ke
• Primary Examiner(s): DOWLING, WILLIAM C
• Application Number:
  US09/394,308
• Time in Patent Office: 802 Days
• Field of Search: 353/20, 353/38, 353/31, 353/33, 353/34, 353/37, 353/94, 353/98, 345/82, 349/61, 349/62, 349/69, 349/70, 385/901, 385/116, 385/133, 362/800
• US Class Current: 353/31
• CPC Class Codes: G02B 27/0994 Fibers, light pipes optical fibers per se G02B6/02
• CPC Class Codes: G03B 21/2073 Polarisers in the lamp house peculiar to electronic spatial light modulators H04N9/3197
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light
• CPC Class Codes: G03B 33/12 using beam-splitting or beam-combining systems, e.g. dichroic mirrors
• CPC Class Codes: H04N 9/3105 for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10
• CPC Class Codes: H04N 9/3164 using multiple light sources
• CPC Class Codes: H04N 9/3167 for polarizing the light beam polarizing optical systems per se G02B27/28

Abstract

An illumination device and an image projection apparatus having the same. The illumination device has a light source with multiple light emitting devices and an uniform illuminating means evenly distributed in front of the light source. The light emitted from the light source can thus uniformly project on a light valve. In addition, a polarization converter is used to convert the light into a usable polarization type, so as to increase the illumination efficiency. The image projection apparatus basically has three of the above mentioned illumination devices to emit three elementary color lights projecting onto a screen.

Claims

1. An illumination device, comprising:

at least a light source;

at least an array of taper light pipes, disposed in front of the light source; and

a uniform illuminating means comprising a guiding taper light pipe, disposed in front of the array taper light pipes and covering a range of the array of taper light pipes from which a light is coming out.

2. The illumination device according to claim 1, wherein the light source comprises a plurality of light emitting devices.

3. The illumination device according to claim 2, wherein the light emitting devices are selected from a group of optical devices consisting of light emitting diodes, organic light emitting diodes, laser diodes, electro-luminescence devices, field emission displays, and cold cathode fluorescence lamps.

4. The illumination device according to claim 1, wherein the array of taper light pipes has multiple taper light pipes through which a light emitted from the light source travels in a form of total reflection.

5. The illumination device according to claim 1, comprising further a plurality of polarization converters in front of the uniform illuminating means.

6. The illumination device according to claim 1, comprising further a polarization converter between the array of taper light pipes and the uniform illuminating means.

7. The illumination device according to claim 6, wherein the polarization converter comprising a pair of parallel polarization beam splitters disposed with an angle to a surface of the array of glass taper rods from which a light coming out, and a half-wave plate.

8. The illumination device according to claim 1, comprising further a plurality of the light sources incorporated with a plurality of the arrays of taper light pipes and a plurality of polarization converters.

9. The illumination device according to claim 1, comprising further a number of polarization converters between the light source and the uniform illuminating means, wherein the number of the polarization converter is equal to the number of the taper light pipes.

10. The illumination device according to claim 1, comprising further a polarization converter in front of the uniform illuminating means.

11. An illumination device, comprising:

a plurality of light emitting devices;

at least an array of taper light pipes, disposed in front of the light source; and

a uniform illuminating means, disposed in front of the array taper light pipes and covering a range of the array of taper light pipes from which a light is coming out.

12. An illumination device, comprises:

at least a light source;

at least an array of taper light pipes, disposed in front of the light source;

an array of gradient refractive index lenses, disposed in front of the array of taper light pipes to cover a surface range from which a light coming out; and

a converging means, in front of the array of gradient refractive index lenses.

13. The illumination device according to claim 12, wherein the light source comprises a plurality of light emitting devices selected from low power consumption devices.

14. The illumination device according to claim 13, wherein the light emitting devices include one selected from the group consisting of light emitting diodes, organic light emitting diodes, laser diodes, electro-luminescence devices, field emission displays, and cold cathode fluorescence lamps.

15. The illumination device according to claim 12, wherein the array of gradient refractive index lenses has a number of gradient refractive index lenses, wherein the number of gradient refractive index lenses is equal to the number of the taper light pipes.

16. The illumination device according to claim 12, comprising further a plurality of polarization converters between the array of the gradient refractive index lenses and the converging means.

17. The illumination device according to claim 16, wherein a number of the polarization converters is the same as a number of the gradient refractive index lenses.

18. The illumination device according to claim 12, comprising further a plurality of polarization converters between the array of taper light pipes and the array of the gradient refractive index lenses.

19. The illumination device according to claim 18, wherein a number of the polarization converters is the same as a number of the gradient refractive index lenses.

20. An illumination device, comprising:

at least a light source;

at least an array of taper light pipes, disposed in front of the light source;

a first lens array in front of the array of the taper light pipes;

a second lens array in front of the first lens array;

a plurality of polarization converters in front of the second lens array; and

a converging means in front of the polarization converters.

21. The illumination device according to claim 20, wherein the light source comprises a plurality of light emitting devices selected from low power consumption devices.

22. The illumination device according to claim 21, wherein the light emitting devices, the taper light pipes, a plurality of first lenses in the first lens array, and a plurality of second lenses of the second lens array have an equal amount.

23. An image projecting apparatus, comprising:

a green illumination device;

a green light valve with respect to the green illumination device to collect a green light emitted from the green illumination device;

a blue illumination device;

a blue light valve with respect to the blue illumination device to collect a blue light emitted from the blue illumination device;

a red illumination device;

a red light valve with respect to the red illumination device to collect a red light emitted from the red illumination device;

a color synthesizing means located at a position, to receive and synthesize the green light, the blue light and the red light transmitting through the green, blue and red light valves;

wherein each of the green, blue, and red illumination devices further comprising at least;

a light source;

an array of taper light pipes; and

a uniformizing device.

24. The image projecting apparatus according to claim 23, wherein the color synthesizing means includes a dichroic prism.

25. The image projecting apparatus according to claim 23, wherein each of the green, blue and red illumination devices further comprise a polarization converter between the array of taper light pipes and the uniform illuminating means.

26. The image projecting apparatus according to claim 23, wherein each of the green, blue and red illumination devices further comprise a polarization converter in front of the uniform illuminating means.

27. The image projecting apparatus according to claim 23, wherein the uniform illuminating means includes an array of gradient refractive index lenses.

28. The image projecting apparatus according to claim 23, wherein the uniform illuminating means includes a first lens array and a second lens array.