Image projector including optical fiber which couples laser illumination to light modulator

• US 6,480,634 B1
• Filed: 05/18/2000
• Issued: 11/12/2002
• Est. Priority Date: 05/18/2000
• Status: Expired due to Fees

• Current Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Original Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Inventors: Corrigan, Robert W.
• Primary Examiner(s): Bovernick, Rodney
• Assistant Examiner(s): Kang, Juliana K.
• Application Number:
  US09/574,733
• Time in Patent Office: 908 Days
• Field of Search: 385/115, 385/116, 385/1-3, 385/4, 385/33, 353/30, 353/31, 353/122, 353/72, 359/618, 359/627
• US Class Current: 385/4
• CPC Class Codes: G02B 2006/12107 Grating
• CPC Class Codes: G02B 26/0808 by means of one or more diffracting elements
• CPC Class Codes: G02B 27/54 Schlieren-optical systems
• CPC Class Codes: G02B 6/425 Optical features semiconductor laser arrays H01S5/40; hybrid LED arrays H01L25/0753; monolithic LED arrays H01L27/153
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161

Abstract

An image projector projects an image onto a display screen and includes a laser source unit, an optical fiber, and a projector head. The projector head includes a light modulator and an optical projection arrangement. The optical fiber couples a laser illumination to the light modulator of the projector head from the laser source unit. The light modulator modulates the laser illumination to produce an array of pixels. The optical projection arrangement projects the array of pixels onto the display screen to produce the image on the display screen. Preferably, the image projector is a color image projector. In the color image projector, the laser source unit includes red, green, and blue lasers, which illuminate first, second, third light modulators. The first, second, and third light modulators produce red, green, and blue arrays of pixels, which the optical projection arrangement projects onto the display screen to produce a color image.

Claims

1. An apparatus for projecting an image onto a display screen comprising:

a. an optical fiber configured to carry a laser illumination to a downstream end of the optical fiber;

b. a projector head comprising;

i. a light modulator driven by electronic means, wherein the downstream end of the optical fiber is coupled to the light modulator such that the light modulator modulates the laser illumination to produce an array of modulated pixels collectively comprising a first and second mode of laser light coming from the light modulator according to a control of the electronic means; and

ii. an optical projection arrangement coupled to the light modulator such that the optical projection arrangement projects the array of pixels onto the display screen to produce the image; and

c. a laser source unit for producing laser illumination, wherein the laser source unit is optically coupled and mechanically isolated from the projector head.

2. The apparatus of claim 1 further comprising a micro-lens arrangement coupled to the downstream end of the optical fiber and configured such that the micro-lens arrangement couples the laser illumination to the light modulator.

3. The apparatus of claim 2 further comprising a laser driven by the electronic means and coupled to an upstream end of the optical fiber such that the laser provides the laser illumination.

4. The apparatus of claim 1 further comprising an additional optical fiber configured to carry an additional laser illumination to the downstream end of the additional optical fiber such that the light modulator modulates the laser illumination and the additional laser illumination.

5. The apparatus of claim 1 wherein the light modulator comprises a diffractive light valve.

6. The apparatus of claim 5 wherein the diffractive light valve comprises a grating light valve.

7. The apparatus of claim 6 wherein:

a. the array of pixels produced by the grating light valve comprises a linear array of pixels;

b. the first and second modes of laser light respectively comprise the diffracted mode and the reflected mode; and

c. the optical projection arrangement comprises;

i. separating optics which allow the diffracted portion of diffracted and reflected light coming from the grating light valve to pass the separating optics;

ii. projection optics which project the linear array of pixels onto the display screen; and

iii. scanning optics driven by the electronic means such that the scanning optics scans the linear array of pixels over the display screen to produce the image.

8. The apparatus of claim 1 wherein the light modulator comprises a reflective light modulator.

9. The apparatus of claim 1 wherein the light modulator comprises a transmissive light modulator.

10. The apparatus according to claim 1 wherein the first and second mode are selected from a group consisting of reflected and diffracted modes, reflected toward and reflected away modes, and a transmissive mode and a non-transmissive mode.

11. An apparatus for projecting a color image onto a display screen comprising:

a. a red laser source for producing a red laser illumination;

b. a blue laser source for producing a blue laser illumination;

c. a green laser source for producing a green laser illumination;

d. a first optical fiber configured to carry the red laser illumination to a first downstream end of the first optical fiber;

e. a second optical fiber configured to carry the green laser illumination to a second downstream end of the second optical fiber;

f. a third optical fiber configured to carry the blue laser illumination to a third downstream end of the third optical fiber;

g. a projector head comprising;

i. means for modulating light which is driven by electronic means and coupled to the first, second, and third downstream ends of the first, second, and third optical fibers such that the means for modulating light modulates the red, green, and blue laser illuminations to produce red, green, and blue arrays of modulated pixels collectively comprising a first and second mode of laser light coming from the light modulator according to a control of the electronic means; and

ii. an optical projection arrangement coupled to the light modulator such that the optical projection arrangement projects the red, green, and blue arrays of pixels onto the display screen to produce the color image;

wherein the red laser source, the blue laser source, and the green laser source are optically coupled and mechanically isolated from the projector head.

12. The apparatus of claim 11 further comprising:

a. a first micro-lens arrangement coupled to the first downstream end of the first optical fiber and configured such that the first micro-lens arrangement couples the red laser illumination to the means for modulating light;

b. a second micro-lens arrangement coupled to the second downstream end of the second optical fiber and configured such that the second micro-lens arrangement couples the green laser illumination to the means for modulating light; and

c. a third micro-lens arrangement coupled to the third downstream end of the third optical fiber and configured such that the third micro-lens arrangement couples the blue laser illumination to the means for modulating light.

13. The apparatus of claim 12 further comprising:

a. a red laser driven by the electronic means and coupled to a first upstream end of the first optical fiber such that the red laser provides the red laser illumination;

b. a green laser driven by the electronic means and coupled to a second upstream end of the second optical fiber such that the green laser provides the green laser illumination; and

c. a blue laser driven by the electronic means and coupled to a third upstream end of the third optical fiber such that the blue laser provides the blue laser illumination.

14. The apparatus of claim 11 further comprising a fourth optical fiber configured to carry an addition laser illumination selected from the group consisting of an additional red, green, and blue laser illuminations to a fourth downstream end of the fourth optical fiber such that the means for modulating light modulates the red, green, and blue laser illuminations and the additional laser illumination.

15. The apparatus of claim 11:

a. wherein the means for modulating light comprises a red light modulator, a green light modulator, and a blue light modulator; and

b. further wherein;

i. the red light modulator modulates the red laser illumination to produce the red array of pixels;

ii. the green light modulator modulates the green laser illumination to produce the green array of pixels; and

iii. the blue light modulator modulates the blue laser illumination to produce the blue array of pixels.

16. The apparatus of claim 15 wherein:

a. the red light modulator comprises a red diffractive light valve;

b. the green light modulator comprises a green diffractive light valve; and

c. the blue light modulator comprises a blue diffractive light valve.

17. The apparatus of claim 16 wherein:

a. the red diffractive light valve comprises a red grating light valve;

b. the green diffractive light valve comprises a green grating light valve; and

c. the blue diffractive light valve comprises a blue grating light valve.

18. The apparatus of claim 17 wherein:

a. the red array of pixels produced by the red grating light valve comprises a red linear array of pixels;

b. the green array of pixels produced by the green grating light valve comprises a green linear array of pixels,

c. the blue array of pixels produced by the blue grating light valve comprises a blue linear array of pixels; and

d. the optical projection arrangement comprises;

i. combining optics which combine diffracted and reflected light coming from the red, green and blue grating light valves, the combining optics forming a color linear array of pixels comprising the red, green, and blue linear arrays of pixels;

ii. separating optics which allow a diffracted portion of the diffracted and reflected light coming from the red, green, and blue grating light valves to pass the separating optics;

iii. projection optics which project the color linear array of pixels onto the display screen; and

iv. scanning optics driven by the electronic means such that the scanning optics scan the color linear array of pixels over the display screen to produce the color image.

19. The apparatus of claim 18 further comprising:

a. a first micro-lens arrangement coupled to the first downstream end of the first optical fiber and configured such that the first micro-lens arrangement couples the red laser illumination to the means for modulating light;

b. a second micro-lens arrangement coupled to the second downstream end of the second optical fiber and configured such that the second micro-lens arrangement couples the green laser illumination to the means for modulating light; and

c. a third micro-lens arrangement coupled to the third downstream end of the third optical fiber and configured such that the third micro-lens arrangement couples the blue laser illumination to the means for modulating light.

20. The apparatus of claim 15 wherein:

a. the red light modulator comprises a red reflective light modulator;

b. the green light modulator comprises a green reflective light modulator; and

c. the blue light modulator comprises a blue reflective light modulator.

21. The apparatus of claim 15 wherein:

a. the red light modulator comprises a red transmissive light modulator;

b. the green light modulator comprises a green transmissive light modulator; and

c. the blue light modulator comprises a blue transmissive light modulator.

22. The apparatus of claim 11 wherein the means for modulating light comprises a diffractive light valve.

23. The apparatus of claim 11 wherein the means for modulating light comprises a reflective light modulator.

24. The apparatus of claim 11 wherein the means for modulating light comprises a transmissive light modulator.

25. The apparatus of claim 22, 23, 24 wherein the diffractive light valve comprises a grating light valve.

26. The apparatus of claim 25:

a. wherein the grating light valve comprises a linear grating light valve; and

b. further comprising;

i. means for sequentially illuminating the grating light valve driven by the electronic means such that the means for sequentially illuminating causes the red, green, and blue laser illuminations to sequentially illuminate the grating light valve to sequentially produce a red linear array of pixels, a green linear array of pixels, and a blue linear array of pixels, whereby a line sequential color is produced, the means for sequentially illuminating repeatedly producing the line sequential color;

ii. separating optics which allow a diffracted portion of diffracted and reflected light coming from grating light valve to pass the separating optics;

iii. projection optics which project the red, green and blue linear arrays of pixels onto the display screen; and

iv. scanning optics driven by the electronic means such that the scanning optics scan the line sequential color over the display screen to produce the color image.

27. The apparatus according to claim 11 wherein the first and second mode are selected from a group consisting of reflected and diffracted modes, reflected toward and reflected away modes, and a transmissive mode and a non-transmissive mode.

28. An apparatus for projecting a color image comprising:

a. first, second and third optical fibers, the first optical fiber transmitting a red laser light to a first fiber end, the second optical fiber transmitting a green laser light to a second fiber end, the third optical fiber transmitting a blue laser light to a third fiber end;

b. a red laser source unit for generating the red laser light, configured such that the red laser light is transmitted into a source end of the first optical fiber;

c. a green laser source unit for generating the green laser light, configured such that the green laser light is transmitted into a source end of the second optical fiber;

d. a blue laser source unit for generating the blue laser light, configured such that the blue laser light is transmitted into a source end of the third optical fiber;

e. a projector head comprising;

i) first, second, and third micro-optics, the first micro-optics coupled to the first fiber end, the second micro-optics coupled to the second fiber end, and the third micro-optics coupled to the third fiber end;

ii) first, second, and third grating light valves each driven by electronic means, the first grating light valve coupled to the first micro-optics and illuminated by the red laser light to produce a red linear array of pixels, the second grating light valve coupled to the second micro-optics and illuminated by the green laser light to produce a green linear array of pixels, and the third grating light valve coupled to the third micro-optics and illuminated by the blue laser light to produce a blue linear array of pixels;

iii) combining optics combining diffracted and reflected light coming from the first, second, and third grating light valves, the combining optics forming a color linear array of pixels comprising the red, green, and blue linear arrays of pixels;

iv) separating optics coupled to the combining optics and allowing a diffracted portion of the diffracted and reflected light to pass the separating optics;

v) projection optics projecting the color linear array of pixels onto a display screen; and

vi) scanning optics driven by the electronic means and scanning the color linear array of pixels over the display screen to produce the color image, wherein the projector head is optically coupled to and mechanically isolated from the red laser source unit, the green laser source unit and the blue laser source unit.

29. An apparatus for projecting a color image comprising:

a. first, second and third optical fibers, the first optical fiber transmitting a red laser light to a first fiber end, the second optical fiber transmitting a green laser light to a second fiber end, the third optical fiber transmitting a blue laser light to a third fiber end;

b. a red laser source unit for generating the red laser light, configured such that the red laser light is transmitted into a source end of the first optical fiber;

c. a green laser source unit for generating the green laser light, configured such that the green laser light is transmitted into a source end of the second optical fiber;

d. a blue laser source unit for generating the blue laser light, configured such that the blue laser light is transmitted into a source end of the third optical fiber; and

e. a projector head comprising;

i) first, second, and third micro-optics, the first micro-optics coupled to the first fiber end, the second micro-optics coupled to the second fiber end, and the third micro-optics coupled to the third fiber end;

ii) combining optics coupled to the first, second, and third micro-optics;

iii) means for sequentially illuminating the combining optics such that the red, green, and blue laser light sequentially and repeatedly illuminates the combining optics;

iv) a grating light valve driven by electronic means and coupled to the combining optics such that the red, green, and blue laser light sequentially and repeatedly illuminate the grating light valve, the grating light valve producing sequential red, green, and blue linear arrays of pixels in response to the illumination by the red, green, and blue laser light;

v) separating optics coupled to the grating light valve and allowing a diffracted portion of diffracted and reflected light to pass the separating optics;

vi) projection optics projecting the sequential red, green, and blue linear array of pixels onto a display screen; and

vii) scanning optics driven by the electronic means and scanning the sequential red, green, and blue linear array of pixels over the display screen to produce the color image, wherein the projector head is optically coupled to and mechanically isolated from the red laser source unit, the green laser source unit and the blue laser source unit.