Abstract

In this paper, we present a novel prism with the ability to enhance the contrast ratio and maintain the optical efficiency in a digital light processing projection system. The working theorem for the novel prism is derived as well. In this novel prism design, the ghost ray is directed away from the projection lens by a total internal reflection surface. Since the ghost ray does not even enter the projection lens, the contrast ratio enhancement is more effective than that achieved by an asymmetrical stop. Compared with the conventional method, the full-on/full-off contrast ratio is increased from 9211 to 463471 and the American National Standards Institute contrast ratio is increased from 1771 to 2951. The imaging system efficiency can maintain at 79.8% under the contrast ratio enhancement process. Ghost ray analysis for the novel prism explains the contrast enhancement well.

© 2013 Optical Society of America

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    [CrossRef]
  2. J. W. Pan and S. H. Lin, “Achromatic design in the illumination system for a mini projector with LED light source,” Opt. Express 19, 15750–15759 (2011).
    [CrossRef]
  3. S. P. Marks, “Projector phones: cool app or visual pollution,” New Scientist 201(2697), 18–19 (2009).
    [CrossRef]
  4. 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. Display Technol. 8, 219–224 (2012).
    [CrossRef]
  5. L. J. Hornbeck, “Digital light processing for high-brightness, high-resolution applications,” Proc. SPIE 3013, 27–40 (1997).
    [CrossRef]
  6. Texas Instruments (TI), “DLP discovery optics 101 application note,” http://focus.ti.com/lit/an/dlpa022/dlpa022.pdf .
  7. Texas Instruments Incorporated, “Introduction to Digital Micro Mirror Device (DMD) technology,” , 2008.
  8. J. W. Pan, C. M. Wang, W. S. Sun, and J. Y. Chang, “Portable Digital Micromirror Device projector using a novel prim,” Appl. Opt. 46, 5097–5102 (2007).
  9. Y. Meuret and P. De Visschere, “Contrast-improving methods for Digital Micromirror Device projectors,” Opt. Eng. 42, 840–845 (2003).
    [CrossRef]
  10. P. J. Janssen and J. A. Shimizu, “High contrast illumination system for video projector,” U.S. Patent5,442,414 (Aug.15, 1995).
  11. G. P. Pinho, “Optics of digital cinema,” Proc. SPIE 5002, 123–131 (2003).
    [CrossRef]
  12. W. J. Smith, Modern Optical Engineering, 4th ed. (McGraw-Hill, 2008), pp. 185–186.
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    [CrossRef]
  14. Y. C. Fang, W. T. Lin, and H. L. Tsai, “High-definition DLP zoom projector lens design with TIR prism for high-definition television (HDTV),” Proc. SPIE 6342, 63420Z (2006).
    [CrossRef]
  15. J. W. Bowron and R. P. Jonas, “Off-axis illumination design for DMD systems,” Proc. SPIE 5186, 72–82 (2003).
  16. M. Yamanaka and M. Nishio, “Air gap prism and method for producing same,” U.S. Patent5,900,984 (May4, 1999).
  17. Optical Research Associates (ORA). http://optics.synopsys.com/index.html .
  18. E. H. Stupp and M. S. Brennesholtz, “Characteristics and characterization,” in Projection Displays, A. C. Lowe, ed.(Wiley, 1999), Chap. 13, pp. 289–319.
  19. American National Standards Institute (ANSI), “American National Standard for Audiovisual Systems-Electronic Projection-Fixed Resolution Projectors,” ANSI/NAPM IT7.228-1997, 1997.
  20. W. J. Smith, Modern Optical Engineering (McGraw-Hill, 2008), pp. 619–621.
  21. M. Inamoto, “Asymmetric aperture diaphragm placing structure for projection lens and projection type image display apparatus using the same,” U.S. Patent6,942,349 (13September, 2005).

2012 (1)

2011 (1)

2009 (1)

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

2008 (1)

2007 (2)

2006 (1)

Y. C. Fang, W. T. Lin, and H. L. Tsai, “High-definition DLP zoom projector lens design with TIR prism for high-definition television (HDTV),” Proc. SPIE 6342, 63420Z (2006).
[CrossRef]

2003 (3)

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

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

G. P. Pinho, “Optics of digital cinema,” Proc. SPIE 5002, 123–131 (2003).
[CrossRef]

1997 (1)

L. J. Hornbeck, “Digital light processing for high-brightness, high-resolution applications,” Proc. SPIE 3013, 27–40 (1997).
[CrossRef]

Ahn, T. J.

Bowron, J. W.

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

Brennesholtz, M. S.

E. H. Stupp and M. S. Brennesholtz, “Characteristics and characterization,” in Projection Displays, A. C. Lowe, ed.(Wiley, 1999), Chap. 13, pp. 289–319.

Chang, J. Y.

Chang, J.-Y.

Choi, K. Y.

Cui, J. C.

De Visschere, P.

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

Fang, Y. C.

Y. C. Fang, W. T. Lin, and H. L. Tsai, “High-definition DLP zoom projector lens design with TIR prism for high-definition television (HDTV),” Proc. SPIE 6342, 63420Z (2006).
[CrossRef]

Fang, Z. L.

Hornbeck, L. J.

L. J. Hornbeck, “Digital light processing for high-brightness, high-resolution applications,” Proc. SPIE 3013, 27–40 (1997).
[CrossRef]

Inamoto, M.

M. Inamoto, “Asymmetric aperture diaphragm placing structure for projection lens and projection type image display apparatus using the same,” U.S. Patent6,942,349 (13September, 2005).

Janssen, P. J.

P. J. Janssen and J. A. Shimizu, “High contrast illumination system for video projector,” U.S. Patent5,442,414 (Aug.15, 1995).

Jeong, S. S.

Jonas, R. P.

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

Jung, Y.

Lee, S. G.

Lin, S. H.

Lin, W. T.

Y. C. Fang, W. T. Lin, and H. L. Tsai, “High-definition DLP zoom projector lens design with TIR prism for high-definition television (HDTV),” Proc. SPIE 6342, 63420Z (2006).
[CrossRef]

Marks, S. P.

S. P. Marks, “Projector phones: cool app or visual pollution,” New Scientist 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, 840–845 (2003).
[CrossRef]

Mu, G.-G.

Nishio, M.

M. Yamanaka and M. Nishio, “Air gap prism and method for producing same,” U.S. Patent5,900,984 (May4, 1999).

Pan, J. W.

Pinho, G. P.

G. P. Pinho, “Optics of digital cinema,” Proc. SPIE 5002, 123–131 (2003).
[CrossRef]

Shimizu, J. A.

P. J. Janssen and J. A. Shimizu, “High contrast illumination system for video projector,” U.S. Patent5,442,414 (Aug.15, 1995).

Shin, S. C.

Smith, W. J.

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

W. J. Smith, Modern Optical Engineering (McGraw-Hill, 2008), pp. 619–621.

Stupp, E. H.

E. H. Stupp and M. S. Brennesholtz, “Characteristics and characterization,” in Projection Displays, A. C. Lowe, ed.(Wiley, 1999), Chap. 13, pp. 289–319.

Sun, W. S.

Tsai, H. L.

Y. C. Fang, W. T. Lin, and H. L. Tsai, “High-definition DLP zoom projector lens design with TIR prism for high-definition television (HDTV),” Proc. SPIE 6342, 63420Z (2006).
[CrossRef]

Tu, S.-H.

Wang, C. M.

Wang, C.-M.

Yamanaka, M.

M. Yamanaka and M. Nishio, “Air gap prism and method for producing same,” U.S. Patent5,900,984 (May4, 1999).

Zhang, X.

Zhao, X.

Appl. Opt. (3)

J. Display Technol. (1)

New Scientist (1)

S. P. Marks, “Projector phones: cool app or visual pollution,” New Scientist 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, 840–845 (2003).
[CrossRef]

Opt. Express (1)

Proc. SPIE (4)

G. P. Pinho, “Optics of digital cinema,” Proc. SPIE 5002, 123–131 (2003).
[CrossRef]

L. J. Hornbeck, “Digital light processing for high-brightness, high-resolution applications,” Proc. SPIE 3013, 27–40 (1997).
[CrossRef]

Y. C. Fang, W. T. Lin, and H. L. Tsai, “High-definition DLP zoom projector lens design with TIR prism for high-definition television (HDTV),” Proc. SPIE 6342, 63420Z (2006).
[CrossRef]

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

Other (10)

M. Yamanaka and M. Nishio, “Air gap prism and method for producing same,” U.S. Patent5,900,984 (May4, 1999).

Optical Research Associates (ORA). http://optics.synopsys.com/index.html .

E. H. Stupp and M. S. Brennesholtz, “Characteristics and characterization,” in Projection Displays, A. C. Lowe, ed.(Wiley, 1999), Chap. 13, pp. 289–319.

American National Standards Institute (ANSI), “American National Standard for Audiovisual Systems-Electronic Projection-Fixed Resolution Projectors,” ANSI/NAPM IT7.228-1997, 1997.

W. J. Smith, Modern Optical Engineering (McGraw-Hill, 2008), pp. 619–621.

M. Inamoto, “Asymmetric aperture diaphragm placing structure for projection lens and projection type image display apparatus using the same,” U.S. Patent6,942,349 (13September, 2005).

Texas Instruments (TI), “DLP discovery optics 101 application note,” http://focus.ti.com/lit/an/dlpa022/dlpa022.pdf .

Texas Instruments Incorporated, “Introduction to Digital Micro Mirror Device (DMD) technology,” , 2008.

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

P. J. Janssen and J. A. Shimizu, “High contrast illumination system for video projector,” U.S. Patent5,442,414 (Aug.15, 1995).

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Figures (11)

Fig. 1.
Fig. 1.

Schematic diagram of the novel prism, consisting of three transparent prisms at the on state of the DMD chip.

Fig. 2.
Fig. 2.

Ray tracing sequence when DMD chip is in the flat state and the limitation points.

Fig. 3.
Fig. 3.

Arrangement of the DMD chip, the novel prism, and the projection lens: (a) on-state light is directed into the projection lens, (b) flat-state light and (c) off-state light are reflected away from the projection lens.

Fig. 4.
Fig. 4.

Schematic diagram of the DLP projector with novel prism.

Fig. 5.
Fig. 5.

FO:FO contrast ratio and imaging system efficiency versus θA using the novel prism.

Fig. 6.
Fig. 6.

Schematic diagram of projection lens stop with asymmetric stop.

Fig. 7.
Fig. 7.

FO:FO contrast ratio and imaging system efficiency versus asymmetric stop position in a conventional prism.

Fig. 8.
Fig. 8.

Comparison of the ANSI contrast ratios obtained with the novel prism and asymmetric stop.

Fig. 9.
Fig. 9.

Example of the novel prism.

Fig. 10.
Fig. 10.

Three main ghost ray paths in model 1: (a) path 1, (b) path 2, and (c) path 3.

Fig. 11.
Fig. 11.

Two main ghost ray paths in model 2: (a) path 1 and (b) path 2.

Tables (4)

Tables Icon

Table 1. Results of the Simulations

Tables Icon

Table 2. Parameters of the Novel Prism

Tables Icon

Table 3. Ghost Ray Analysis Data Used in the Conventional Prism Projection System

Tables Icon

Table 4. Ghost Ray Analysis Data Used in the Projection System with a Novel Prism

Equations (9)

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

θE>sin11np+sin1{1npsin[θin+sin1(12F)]}.
θA<sin11np+sin1sin[θDMDsin1(12F)]np.
θA>sin1(1np)sin1sin[θDMDsin1(12F)]np.
θB=180°+sin1(1npsinθin)2θE+sin1(1npsinθDMD).
a=t+2d2tan(sin112F)+2d1tan(sin112F×np)tan(θB90°+sin112F×np)+tan(180°θBθE),
b=tan(180°θBθE)t+2d2tan(sin112F)+2d1tan(sin112F×np)+ktan(θB90°+sin112F×np)+tan(180°θBθE)+t2+d2tan(sin112F)+d1tan(sin112F×np).
c=d1[t2+d2tan(sin112F)+d1tan(sin112F×np)+k],
d=[t2+d2tan(sin112F)+d1tan(sin112F×np)+k].
FO:FOcontrast ratio=L(white)L(black),

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