Abstract

In this paper, a novel light separator with contrast ratio enhancement but maintaining the optical efficiency of the DLP projection system is proposed. The main capability of the novel light separator is to direct the uncontrolled light away from the image system. The working theorem for the novel light separator is derived as well. Uncontrolled light is kept away from the image system by a total internal reflection surface, thereby effectively improving the image quality. Compared with the conventional contrast ratio enhancement method, the FO:FO contrast ratio can be improved from 839:1 to 48250:1, the ANSI contrast ratio can be improved from 180:1 to 306:1, while the image system efficiency remains at 76.2%.

© 2014 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. X. Zhao, Z. L. Fang, J. C. Cui, X. Zhang, and G.-G. Mu, “Illumination system using LED sources for pocket-size projectors,” Appl. Opt. 46(4), 522–526 (2007).
    [CrossRef] [PubMed]
  2. C.-M. Chang and H.-P. D. Shieh, “Design of illumination and projection optics for projectors with single digital micromirror devices,” Appl. Opt. 39(19), 3202–3208 (2000).
    [CrossRef] [PubMed]
  3. J. W. Pan, S. H. Tu, C. M. Wang, and J. Y. Chang, “High efficiency pocket-size projector with a compact projection lens and a light emitting diode-based light source system,” Appl. Opt. 47(19), 3406–3414 (2008).
    [CrossRef] [PubMed]
  4. J. W. Pan and S. H. Lin, “Achromatic design in the illumination system for a mini projector with LED light source,” Opt. Express 19(17), 15750–15759 (2011).
    [CrossRef] [PubMed]
  5. S. P. Marks, “Projector phones: Cool app or visual pollution,” New Sci. 201(2697), 18–19 (2009).
    [CrossRef]
  6. S. C. Shin, Y. Jung, T. J. Ahn, S. S. Jeong, S. G. Lee, and K. Y. Choi, “The compact systems design based on DMD and the straight line 2-channel LED for a mobile embedded pico projector,” J. Disp. Technol. 8(4), 219–224 (2012).
    [CrossRef]
  7. C. Zhang, P. S. Huang, and F. P. Chiang, “Microscopic phase-shifting profilometry based on digital micromirror device technology,” Appl. Opt. 41(28), 5896–5904 (2002).
    [CrossRef] [PubMed]
  8. P. F. Van Kessel, L. J. Hornbeck, R. E. Meier, and M. R. Douglass, “A MEMS-based Projection Display,” in Proceedings of IEEE Conference on Micro Electro Mechanical Systems Workshop (IEEE, 1998), pp. 1687–1704.
    [CrossRef]
  9. Texas Instruments Incorporated, “Introduction to Digital Micro Mirror Device (DMD) Technology,” Appl. Rep. DLPA008 (2008).
  10. Texas Instruments (TI), “DLP® Discovery Optics 101 Application Note,” http://focus.ti.com/lit/an/dlpa022/dlpa022.pdf .
  11. Texas Instruments (TI), “DMD 101: Introduction to Digital Micromirror Device (DMD) Technology,” http://www.ti.com/lit/an/dlpa008a/dlpa008a.pdf .
  12. J. W. Pan, C. M. Wang, W. S. Sun, and J. Y. Chang, “Portable digital micromirror device projector using a prism,” Appl. Opt. 46(22), 5097–5102 (2007).
    [CrossRef] [PubMed]
  13. Y. Meuret and P. De Visschere, “Contrast-improving methods for digital micromirror device projectors,” Opt. Eng. 42(3), 840–845 (2003).
    [CrossRef]
  14. W. J. Smith, Modern Optical Engineering, 4th ed. (McGraw Hill, 2008), pp.185–186.
  15. J. W. Bowron and R. P. Jonas, “Off-axis illumination design for DMD systems,” Proc. SPIE 5186, 72–82 (2003).
    [CrossRef]
  16. Lighttools website: http://optics.synopsys.com/lighttools/ .
  17. E. H. Stupp and M. S. Brennesholtz, “Characteristics and characterization,” in Projection Displays, A. C. Lowe, ed., 2nd ed. (Wiley, 2008), Chap. 13, pp. 311–346.
  18. American National Standards Institute (ANSI), Website http://www.ansi.org/ ; document number: ANSI/NAPM IT7.228–1997.
  19. J. W. Pan and H. H. Wang, “High contrast ratio prism design in a mini projector,” Appl. Opt. 52(34), 8347–8354 (2013).
    [CrossRef] [PubMed]

2013 (1)

2012 (1)

S. C. Shin, Y. Jung, T. J. Ahn, S. S. Jeong, S. G. Lee, and K. Y. Choi, “The compact systems design based on DMD and the straight line 2-channel LED for a mobile embedded pico projector,” J. Disp. Technol. 8(4), 219–224 (2012).
[CrossRef]

2011 (1)

2009 (1)

S. P. Marks, “Projector phones: Cool app or visual pollution,” New Sci. 201(2697), 18–19 (2009).
[CrossRef]

2008 (1)

2007 (2)

2003 (2)

Y. Meuret and P. De Visschere, “Contrast-improving methods for digital micromirror device projectors,” Opt. Eng. 42(3), 840–845 (2003).
[CrossRef]

J. W. Bowron and R. P. Jonas, “Off-axis illumination design for DMD systems,” Proc. SPIE 5186, 72–82 (2003).
[CrossRef]

2002 (1)

2000 (1)

Ahn, T. J.

S. C. Shin, Y. Jung, T. J. Ahn, S. S. Jeong, S. G. Lee, and K. Y. Choi, “The compact systems design based on DMD and the straight line 2-channel LED for a mobile embedded pico projector,” J. Disp. Technol. 8(4), 219–224 (2012).
[CrossRef]

Bowron, J. W.

J. W. Bowron and R. P. Jonas, “Off-axis illumination design for DMD systems,” Proc. SPIE 5186, 72–82 (2003).
[CrossRef]

Chang, C.-M.

Chang, J. Y.

Chiang, F. P.

Choi, K. Y.

S. C. Shin, Y. Jung, T. J. Ahn, S. S. Jeong, S. G. Lee, and K. Y. Choi, “The compact systems design based on DMD and the straight line 2-channel LED for a mobile embedded pico projector,” J. Disp. Technol. 8(4), 219–224 (2012).
[CrossRef]

Cui, J. C.

De Visschere, P.

Y. Meuret and P. De Visschere, “Contrast-improving methods for digital micromirror device projectors,” Opt. Eng. 42(3), 840–845 (2003).
[CrossRef]

Fang, Z. L.

Huang, P. S.

Jeong, S. S.

S. C. Shin, Y. Jung, T. J. Ahn, S. S. Jeong, S. G. Lee, and K. Y. Choi, “The compact systems design based on DMD and the straight line 2-channel LED for a mobile embedded pico projector,” J. Disp. Technol. 8(4), 219–224 (2012).
[CrossRef]

Jonas, R. P.

J. W. Bowron and R. P. Jonas, “Off-axis illumination design for DMD systems,” Proc. SPIE 5186, 72–82 (2003).
[CrossRef]

Jung, Y.

S. C. Shin, Y. Jung, T. J. Ahn, S. S. Jeong, S. G. Lee, and K. Y. Choi, “The compact systems design based on DMD and the straight line 2-channel LED for a mobile embedded pico projector,” J. Disp. Technol. 8(4), 219–224 (2012).
[CrossRef]

Lee, S. G.

S. C. Shin, Y. Jung, T. J. Ahn, S. S. Jeong, S. G. Lee, and K. Y. Choi, “The compact systems design based on DMD and the straight line 2-channel LED for a mobile embedded pico projector,” J. Disp. Technol. 8(4), 219–224 (2012).
[CrossRef]

Lin, S. H.

Marks, S. P.

S. P. Marks, “Projector phones: Cool app or visual pollution,” New Sci. 201(2697), 18–19 (2009).
[CrossRef]

Meuret, Y.

Y. Meuret and P. De Visschere, “Contrast-improving methods for digital micromirror device projectors,” Opt. Eng. 42(3), 840–845 (2003).
[CrossRef]

Mu, G.-G.

Pan, J. W.

Shieh, H.-P. D.

Shin, S. C.

S. C. Shin, Y. Jung, T. J. Ahn, S. S. Jeong, S. G. Lee, and K. Y. Choi, “The compact systems design based on DMD and the straight line 2-channel LED for a mobile embedded pico projector,” J. Disp. Technol. 8(4), 219–224 (2012).
[CrossRef]

Sun, W. S.

Tu, S. H.

Wang, C. M.

Wang, H. H.

Zhang, C.

Zhang, X.

Zhao, X.

Appl. Opt. (6)

J. Disp. Technol. (1)

S. C. Shin, Y. Jung, T. J. Ahn, S. S. Jeong, S. G. Lee, and K. Y. Choi, “The compact systems design based on DMD and the straight line 2-channel LED for a mobile embedded pico projector,” J. Disp. Technol. 8(4), 219–224 (2012).
[CrossRef]

New Sci. (1)

S. P. Marks, “Projector phones: Cool app or visual pollution,” New Sci. 201(2697), 18–19 (2009).
[CrossRef]

Opt. Eng. (1)

Y. Meuret and P. De Visschere, “Contrast-improving methods for digital micromirror device projectors,” Opt. Eng. 42(3), 840–845 (2003).
[CrossRef]

Opt. Express (1)

Proc. SPIE (1)

J. W. Bowron and R. P. Jonas, “Off-axis illumination design for DMD systems,” Proc. SPIE 5186, 72–82 (2003).
[CrossRef]

Other (8)

Lighttools website: http://optics.synopsys.com/lighttools/ .

E. H. Stupp and M. S. Brennesholtz, “Characteristics and characterization,” in Projection Displays, A. C. Lowe, ed., 2nd ed. (Wiley, 2008), Chap. 13, pp. 311–346.

American National Standards Institute (ANSI), Website http://www.ansi.org/ ; document number: ANSI/NAPM IT7.228–1997.

P. F. Van Kessel, L. J. Hornbeck, R. E. Meier, and M. R. Douglass, “A MEMS-based Projection Display,” in Proceedings of IEEE Conference on Micro Electro Mechanical Systems Workshop (IEEE, 1998), pp. 1687–1704.
[CrossRef]

Texas Instruments Incorporated, “Introduction to Digital Micro Mirror Device (DMD) Technology,” Appl. Rep. DLPA008 (2008).

Texas Instruments (TI), “DLP® Discovery Optics 101 Application Note,” http://focus.ti.com/lit/an/dlpa022/dlpa022.pdf .

Texas Instruments (TI), “DMD 101: Introduction to Digital Micromirror Device (DMD) Technology,” http://www.ti.com/lit/an/dlpa008a/dlpa008a.pdf .

W. J. Smith, Modern Optical Engineering, 4th ed. (McGraw Hill, 2008), pp.185–186.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (13)

Fig. 1
Fig. 1

Schematic diagram of the ray tracing sequence when the DMD chip is in the on-state and for critical conditions I&II.

Fig. 2
Fig. 2

Schematic diagram of the ray tracing sequence when the DMD chip is in the flat-state for critical conditions III&IV.

Fig. 3
Fig. 3

Schematic diagram of the ray tracing sequence when the DMD chip is in the flat-state and limit points 1&2.

Fig. 4
Fig. 4

Arrangement of the novel light separator, the DMD chip, and the image system when: (a) on-state rays are directed into the image system; (b) flat-state rays and (c) off-state rays are reflected away from the image system.

Fig. 5
Fig. 5

Schematic diagram of the novel light separator for the DLP projector.

Fig. 6
Fig. 6

The relationship between the FO:FO contrast ratio, image system efficiency and θA.

Fig. 7
Fig. 7

Schematic diagram of the ray tracing sequence with θA set to 31.0 degrees when DMD chip is in the flat-state.

Fig. 8
Fig. 8

Schematics of the pupils. The pupil of the image system F/2.0 is slightly larger than the pupil of the illumination system F/2.4. The deep blue board presents an asymmetric stop. The overlapping area between the projection and flat-state pupil shows the flat-state light leakage into the image system.

Fig. 9
Fig. 9

The relationship between the FO:FO contrast ratio, image system efficiency and asymmetric stop position γ

Fig. 10
Fig. 10

Comparison of the ANSI contrast ratios for the novel light separator and asymmetric stop.

Fig. 11
Fig. 11

A sample of the novel light separator.

Fig. 12
Fig. 12

Three main ghost ray paths in Design 1: optical engine with conventional light separator: (a) path 1, (b) path 2, and (c) path 3.

Fig. 13
Fig. 13

Three main ghost ray paths in Design 2, the optical engine with the novel light separator: (a) path 1, (b) path 2, and (c) path 3.

Tables (4)

Tables Icon

Table 1 Comparison of the novel light separator and the traditional asymmetric stop method

Tables Icon

Table 2 Ghost Ray Analysis of the Projection System with the Conventional Light Separator

Tables Icon

Table 3 Ghost Ray Analysis for the Projection System with the Novel Light Separator

Tables Icon

Table 4 The Comparison of Novel Light Separator and Previous Work

Equations (7)

Equations on this page are rendered with MathJax. Learn more.

sin θ in = n p sin[45° sin 1 ( sin θ DMD n p ) θ E ].
sin 1 { 1 n p sin[ θ in + sin 1 ( 1 2F/# )]}+ θ E < sin 1 ( 1 n p ),
sin 1 ( 1 n p )+ sin 1 sin[ sin 1 ( 1 2F/# ) θ DMD +2 θ t )] n p <45°,
θ A > sin 1 ( 1 n p ) sin 1 { 1 n p sin[ θ DMD sin 1 ( 1 2F/# )]}.
θ A < 1 2 { sin 1 ( 1 n b ) sin 1 { 1 n b sin[ θ DMD + sin 1 ( 1 2F/# )]}+45°}.
a=L{ 1 1tan[ θ DMD + sin 1 ( 1 2F/# )] [ksin( 45°+ θ A ) 2 d 1 n p sin[ θ DMD + sin 1 ( 1 2F/# )] 2 d 2 tan[ θ DMD + sin 1 ( 1 2F/# )]
b=L(L{ 1 1tan[ θ DMD + sin 1 ( 1 2F/# )] [ksin( 45°+ θ A ) 2 d 1 n p sin[ θ DMD + sin 1 ( 1 2F/# )] 2 d 2 tan[ θ DMD + sin 1 ( 1 2F/# )]})tan θ A .

Metrics