Abstract

A simple and accurate measurement method for determining the cell parameters of a twisted nematic liquid-crystal display (TN-LCD) is proposed. Based on the measurement of the maximum reflectance and the maximum transmittance of a TN-LCD by rotating the polarizer at a particular angle, between the front director of the liquid crystals and the transmission axis of the polarizer, the cell gap and the twist angle can be determined according to the Jones matrix theory, and the twist sense can also be determined easily by applying an external small voltage to slightly change the effective refractive index of the liquid crystal.

© 2007 Optical Society of America

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  1. R. Kiefer, B. Webber, F. Windscheid, and G. Baur, "In-plane switching of nematic liquid crystals," Proc. Jpn. Display , 547-550 (1992).
  2. A. Takeda, S. Kataoka, T. Sasaki, H. Chida, H. Tsuda, K. Ohmuro, T. Sasabayashi, Y. Koike, and K. Okamoto, "A super-high image quality multi-domain vertical alignment LCD by new rubbing-less technology," SID Symp. Digest 1077-1080 (1998).
    [CrossRef]
  3. H. Kim, J. Song, S. Park, J. Lyu, J. Souk, and K. Lee, "PVA technology for high performance LCD monitors," J. Info. Displays 1, 3-8 (2000).
  4. M. Schadt and W. Helfrich, "Voltage-dependent optical activity of a twisted nematic liquid crystal," Appl. Phys. Lett. 18, 127-128 (1971).
    [CrossRef]
  5. T. J. Scheffer and J. Nehring, "A new, highly multiplexable liquid crystal display," Appl. Phys. Lett. 45, 1021-1023 (1984).
    [CrossRef]
  6. C. Mauguin, "Sur les cristaux liquides de Lehmann," Bull. Soc. Fr. Mineral. 34, 71-117 (1911).
  7. C. H. Gooch and H. A. Tarry, "The optical properties of twisted nematic liquid crystal structure with twisted angle 90°," J. Phys. D 8, 1575-1584 (1975).
    [CrossRef]
  8. K. H. Yang, "Measurements of empty cell gap for liquid-crystal displays using interferometric methods," J. Appl. Phys. 64, 4780-4781 (1988).
    [CrossRef]
  9. A. Lien and H. Takano, "Cell gap measurement of filled twist nematic liquid crystal displays by a phase compensation method," J. Appl. Phys. 69, 1304-1309 (1991).
    [CrossRef]
  10. S. T. Tang and H. S. Kwok, "Transmissive liquid crystal cell parameters measurement by spectroscopic ellipsometry," J. Appl. Phys. 89, 80-85 (2001).
    [CrossRef]
  11. J. S. Chae and S. G. Moon, "Cell parameter measurement of a twist-nematic liquid crystal cell by the spectroscopic method," J. Appl. Phys. 95, 3250-3254 (2004).
    [CrossRef]
  12. Y. Zhou, Z. He, and S. Sato, Jpn. J. Appl. Phys. , Part 1 36, 2760-2764 (1997).
    [CrossRef]
  13. J. S. Gwag, S. H. Lee, K.-Y. Han, J. C. Kim, and T.-H. Yoon, "Novel cell gap measurement method for a liquid crystal cell," Jpn. J. Appl. Phys. 41, L79-L82 (2002).
    [CrossRef]
  14. P. Yeh and C. Gu, Optics of Liquid Crystal Display (Wiley, 1999), Chap. 4.
  15. S.-T. Wu and C.-S. Wu, "Mixed-mode twisted nematic liquid crystal cells for reflective displays," Appl. Phys. Lett. 68, 1455-1457 (1996).
    [CrossRef]
  16. S. T. Tang and H. S. Kwok, "Measurement of reflective liquid crystal displays," J. Appl. Phys. 91, 8950-8953 (2002).
    [CrossRef]
  17. W.-K. Choi, "Reflective liquid-crystal cell-gap measurement using input-polarization-angle dependence," SID Symp. Digest 33, 530-533 (2002).
    [CrossRef]

2004 (1)

J. S. Chae and S. G. Moon, "Cell parameter measurement of a twist-nematic liquid crystal cell by the spectroscopic method," J. Appl. Phys. 95, 3250-3254 (2004).
[CrossRef]

2002 (3)

J. S. Gwag, S. H. Lee, K.-Y. Han, J. C. Kim, and T.-H. Yoon, "Novel cell gap measurement method for a liquid crystal cell," Jpn. J. Appl. Phys. 41, L79-L82 (2002).
[CrossRef]

S. T. Tang and H. S. Kwok, "Measurement of reflective liquid crystal displays," J. Appl. Phys. 91, 8950-8953 (2002).
[CrossRef]

W.-K. Choi, "Reflective liquid-crystal cell-gap measurement using input-polarization-angle dependence," SID Symp. Digest 33, 530-533 (2002).
[CrossRef]

2001 (1)

S. T. Tang and H. S. Kwok, "Transmissive liquid crystal cell parameters measurement by spectroscopic ellipsometry," J. Appl. Phys. 89, 80-85 (2001).
[CrossRef]

2000 (1)

H. Kim, J. Song, S. Park, J. Lyu, J. Souk, and K. Lee, "PVA technology for high performance LCD monitors," J. Info. Displays 1, 3-8 (2000).

1998 (1)

A. Takeda, S. Kataoka, T. Sasaki, H. Chida, H. Tsuda, K. Ohmuro, T. Sasabayashi, Y. Koike, and K. Okamoto, "A super-high image quality multi-domain vertical alignment LCD by new rubbing-less technology," SID Symp. Digest 1077-1080 (1998).
[CrossRef]

1997 (1)

Y. Zhou, Z. He, and S. Sato, Jpn. J. Appl. Phys. , Part 1 36, 2760-2764 (1997).
[CrossRef]

1996 (1)

S.-T. Wu and C.-S. Wu, "Mixed-mode twisted nematic liquid crystal cells for reflective displays," Appl. Phys. Lett. 68, 1455-1457 (1996).
[CrossRef]

1992 (1)

R. Kiefer, B. Webber, F. Windscheid, and G. Baur, "In-plane switching of nematic liquid crystals," Proc. Jpn. Display , 547-550 (1992).

1991 (1)

A. Lien and H. Takano, "Cell gap measurement of filled twist nematic liquid crystal displays by a phase compensation method," J. Appl. Phys. 69, 1304-1309 (1991).
[CrossRef]

1988 (1)

K. H. Yang, "Measurements of empty cell gap for liquid-crystal displays using interferometric methods," J. Appl. Phys. 64, 4780-4781 (1988).
[CrossRef]

1984 (1)

T. J. Scheffer and J. Nehring, "A new, highly multiplexable liquid crystal display," Appl. Phys. Lett. 45, 1021-1023 (1984).
[CrossRef]

1975 (1)

C. H. Gooch and H. A. Tarry, "The optical properties of twisted nematic liquid crystal structure with twisted angle 90°," J. Phys. D 8, 1575-1584 (1975).
[CrossRef]

1971 (1)

M. Schadt and W. Helfrich, "Voltage-dependent optical activity of a twisted nematic liquid crystal," Appl. Phys. Lett. 18, 127-128 (1971).
[CrossRef]

1911 (1)

C. Mauguin, "Sur les cristaux liquides de Lehmann," Bull. Soc. Fr. Mineral. 34, 71-117 (1911).

Baur, G.

R. Kiefer, B. Webber, F. Windscheid, and G. Baur, "In-plane switching of nematic liquid crystals," Proc. Jpn. Display , 547-550 (1992).

Chae, J. S.

J. S. Chae and S. G. Moon, "Cell parameter measurement of a twist-nematic liquid crystal cell by the spectroscopic method," J. Appl. Phys. 95, 3250-3254 (2004).
[CrossRef]

Chida, H.

A. Takeda, S. Kataoka, T. Sasaki, H. Chida, H. Tsuda, K. Ohmuro, T. Sasabayashi, Y. Koike, and K. Okamoto, "A super-high image quality multi-domain vertical alignment LCD by new rubbing-less technology," SID Symp. Digest 1077-1080 (1998).
[CrossRef]

Choi, W.-K.

W.-K. Choi, "Reflective liquid-crystal cell-gap measurement using input-polarization-angle dependence," SID Symp. Digest 33, 530-533 (2002).
[CrossRef]

Gooch, C. H.

C. H. Gooch and H. A. Tarry, "The optical properties of twisted nematic liquid crystal structure with twisted angle 90°," J. Phys. D 8, 1575-1584 (1975).
[CrossRef]

Gu, C.

P. Yeh and C. Gu, Optics of Liquid Crystal Display (Wiley, 1999), Chap. 4.

Gwag, J. S.

J. S. Gwag, S. H. Lee, K.-Y. Han, J. C. Kim, and T.-H. Yoon, "Novel cell gap measurement method for a liquid crystal cell," Jpn. J. Appl. Phys. 41, L79-L82 (2002).
[CrossRef]

Han, K.-Y.

J. S. Gwag, S. H. Lee, K.-Y. Han, J. C. Kim, and T.-H. Yoon, "Novel cell gap measurement method for a liquid crystal cell," Jpn. J. Appl. Phys. 41, L79-L82 (2002).
[CrossRef]

He, Z.

Y. Zhou, Z. He, and S. Sato, Jpn. J. Appl. Phys. , Part 1 36, 2760-2764 (1997).
[CrossRef]

Helfrich, W.

M. Schadt and W. Helfrich, "Voltage-dependent optical activity of a twisted nematic liquid crystal," Appl. Phys. Lett. 18, 127-128 (1971).
[CrossRef]

Kataoka, S.

A. Takeda, S. Kataoka, T. Sasaki, H. Chida, H. Tsuda, K. Ohmuro, T. Sasabayashi, Y. Koike, and K. Okamoto, "A super-high image quality multi-domain vertical alignment LCD by new rubbing-less technology," SID Symp. Digest 1077-1080 (1998).
[CrossRef]

Kiefer, R.

R. Kiefer, B. Webber, F. Windscheid, and G. Baur, "In-plane switching of nematic liquid crystals," Proc. Jpn. Display , 547-550 (1992).

Kim, H.

H. Kim, J. Song, S. Park, J. Lyu, J. Souk, and K. Lee, "PVA technology for high performance LCD monitors," J. Info. Displays 1, 3-8 (2000).

Kim, J. C.

J. S. Gwag, S. H. Lee, K.-Y. Han, J. C. Kim, and T.-H. Yoon, "Novel cell gap measurement method for a liquid crystal cell," Jpn. J. Appl. Phys. 41, L79-L82 (2002).
[CrossRef]

Koike, Y.

A. Takeda, S. Kataoka, T. Sasaki, H. Chida, H. Tsuda, K. Ohmuro, T. Sasabayashi, Y. Koike, and K. Okamoto, "A super-high image quality multi-domain vertical alignment LCD by new rubbing-less technology," SID Symp. Digest 1077-1080 (1998).
[CrossRef]

Kwok, H. S.

S. T. Tang and H. S. Kwok, "Measurement of reflective liquid crystal displays," J. Appl. Phys. 91, 8950-8953 (2002).
[CrossRef]

S. T. Tang and H. S. Kwok, "Transmissive liquid crystal cell parameters measurement by spectroscopic ellipsometry," J. Appl. Phys. 89, 80-85 (2001).
[CrossRef]

Lee, K.

H. Kim, J. Song, S. Park, J. Lyu, J. Souk, and K. Lee, "PVA technology for high performance LCD monitors," J. Info. Displays 1, 3-8 (2000).

Lee, S. H.

J. S. Gwag, S. H. Lee, K.-Y. Han, J. C. Kim, and T.-H. Yoon, "Novel cell gap measurement method for a liquid crystal cell," Jpn. J. Appl. Phys. 41, L79-L82 (2002).
[CrossRef]

Lien, A.

A. Lien and H. Takano, "Cell gap measurement of filled twist nematic liquid crystal displays by a phase compensation method," J. Appl. Phys. 69, 1304-1309 (1991).
[CrossRef]

Lyu, J.

H. Kim, J. Song, S. Park, J. Lyu, J. Souk, and K. Lee, "PVA technology for high performance LCD monitors," J. Info. Displays 1, 3-8 (2000).

Mauguin, C.

C. Mauguin, "Sur les cristaux liquides de Lehmann," Bull. Soc. Fr. Mineral. 34, 71-117 (1911).

Moon, S. G.

J. S. Chae and S. G. Moon, "Cell parameter measurement of a twist-nematic liquid crystal cell by the spectroscopic method," J. Appl. Phys. 95, 3250-3254 (2004).
[CrossRef]

Nehring, J.

T. J. Scheffer and J. Nehring, "A new, highly multiplexable liquid crystal display," Appl. Phys. Lett. 45, 1021-1023 (1984).
[CrossRef]

Ohmuro, K.

A. Takeda, S. Kataoka, T. Sasaki, H. Chida, H. Tsuda, K. Ohmuro, T. Sasabayashi, Y. Koike, and K. Okamoto, "A super-high image quality multi-domain vertical alignment LCD by new rubbing-less technology," SID Symp. Digest 1077-1080 (1998).
[CrossRef]

Okamoto, K.

A. Takeda, S. Kataoka, T. Sasaki, H. Chida, H. Tsuda, K. Ohmuro, T. Sasabayashi, Y. Koike, and K. Okamoto, "A super-high image quality multi-domain vertical alignment LCD by new rubbing-less technology," SID Symp. Digest 1077-1080 (1998).
[CrossRef]

Park, S.

H. Kim, J. Song, S. Park, J. Lyu, J. Souk, and K. Lee, "PVA technology for high performance LCD monitors," J. Info. Displays 1, 3-8 (2000).

Sasabayashi, T.

A. Takeda, S. Kataoka, T. Sasaki, H. Chida, H. Tsuda, K. Ohmuro, T. Sasabayashi, Y. Koike, and K. Okamoto, "A super-high image quality multi-domain vertical alignment LCD by new rubbing-less technology," SID Symp. Digest 1077-1080 (1998).
[CrossRef]

Sasaki, T.

A. Takeda, S. Kataoka, T. Sasaki, H. Chida, H. Tsuda, K. Ohmuro, T. Sasabayashi, Y. Koike, and K. Okamoto, "A super-high image quality multi-domain vertical alignment LCD by new rubbing-less technology," SID Symp. Digest 1077-1080 (1998).
[CrossRef]

Sato, S.

Y. Zhou, Z. He, and S. Sato, Jpn. J. Appl. Phys. , Part 1 36, 2760-2764 (1997).
[CrossRef]

Schadt, M.

M. Schadt and W. Helfrich, "Voltage-dependent optical activity of a twisted nematic liquid crystal," Appl. Phys. Lett. 18, 127-128 (1971).
[CrossRef]

Scheffer, T. J.

T. J. Scheffer and J. Nehring, "A new, highly multiplexable liquid crystal display," Appl. Phys. Lett. 45, 1021-1023 (1984).
[CrossRef]

Song, J.

H. Kim, J. Song, S. Park, J. Lyu, J. Souk, and K. Lee, "PVA technology for high performance LCD monitors," J. Info. Displays 1, 3-8 (2000).

Souk, J.

H. Kim, J. Song, S. Park, J. Lyu, J. Souk, and K. Lee, "PVA technology for high performance LCD monitors," J. Info. Displays 1, 3-8 (2000).

Takano, H.

A. Lien and H. Takano, "Cell gap measurement of filled twist nematic liquid crystal displays by a phase compensation method," J. Appl. Phys. 69, 1304-1309 (1991).
[CrossRef]

Takeda, A.

A. Takeda, S. Kataoka, T. Sasaki, H. Chida, H. Tsuda, K. Ohmuro, T. Sasabayashi, Y. Koike, and K. Okamoto, "A super-high image quality multi-domain vertical alignment LCD by new rubbing-less technology," SID Symp. Digest 1077-1080 (1998).
[CrossRef]

Tang, S. T.

S. T. Tang and H. S. Kwok, "Measurement of reflective liquid crystal displays," J. Appl. Phys. 91, 8950-8953 (2002).
[CrossRef]

S. T. Tang and H. S. Kwok, "Transmissive liquid crystal cell parameters measurement by spectroscopic ellipsometry," J. Appl. Phys. 89, 80-85 (2001).
[CrossRef]

Tarry, H. A.

C. H. Gooch and H. A. Tarry, "The optical properties of twisted nematic liquid crystal structure with twisted angle 90°," J. Phys. D 8, 1575-1584 (1975).
[CrossRef]

Tsuda, H.

A. Takeda, S. Kataoka, T. Sasaki, H. Chida, H. Tsuda, K. Ohmuro, T. Sasabayashi, Y. Koike, and K. Okamoto, "A super-high image quality multi-domain vertical alignment LCD by new rubbing-less technology," SID Symp. Digest 1077-1080 (1998).
[CrossRef]

Webber, B.

R. Kiefer, B. Webber, F. Windscheid, and G. Baur, "In-plane switching of nematic liquid crystals," Proc. Jpn. Display , 547-550 (1992).

Windscheid, F.

R. Kiefer, B. Webber, F. Windscheid, and G. Baur, "In-plane switching of nematic liquid crystals," Proc. Jpn. Display , 547-550 (1992).

Wu, C.-S.

S.-T. Wu and C.-S. Wu, "Mixed-mode twisted nematic liquid crystal cells for reflective displays," Appl. Phys. Lett. 68, 1455-1457 (1996).
[CrossRef]

Wu, S.-T.

S.-T. Wu and C.-S. Wu, "Mixed-mode twisted nematic liquid crystal cells for reflective displays," Appl. Phys. Lett. 68, 1455-1457 (1996).
[CrossRef]

Yang, K. H.

K. H. Yang, "Measurements of empty cell gap for liquid-crystal displays using interferometric methods," J. Appl. Phys. 64, 4780-4781 (1988).
[CrossRef]

Yeh, P.

P. Yeh and C. Gu, Optics of Liquid Crystal Display (Wiley, 1999), Chap. 4.

Yoon, T.-H.

J. S. Gwag, S. H. Lee, K.-Y. Han, J. C. Kim, and T.-H. Yoon, "Novel cell gap measurement method for a liquid crystal cell," Jpn. J. Appl. Phys. 41, L79-L82 (2002).
[CrossRef]

Zhou, Y.

Y. Zhou, Z. He, and S. Sato, Jpn. J. Appl. Phys. , Part 1 36, 2760-2764 (1997).
[CrossRef]

Appl. Phys. Lett. (3)

M. Schadt and W. Helfrich, "Voltage-dependent optical activity of a twisted nematic liquid crystal," Appl. Phys. Lett. 18, 127-128 (1971).
[CrossRef]

T. J. Scheffer and J. Nehring, "A new, highly multiplexable liquid crystal display," Appl. Phys. Lett. 45, 1021-1023 (1984).
[CrossRef]

S.-T. Wu and C.-S. Wu, "Mixed-mode twisted nematic liquid crystal cells for reflective displays," Appl. Phys. Lett. 68, 1455-1457 (1996).
[CrossRef]

Bull. Soc. Fr. Mineral. (1)

C. Mauguin, "Sur les cristaux liquides de Lehmann," Bull. Soc. Fr. Mineral. 34, 71-117 (1911).

J. Appl. Phys. (5)

K. H. Yang, "Measurements of empty cell gap for liquid-crystal displays using interferometric methods," J. Appl. Phys. 64, 4780-4781 (1988).
[CrossRef]

A. Lien and H. Takano, "Cell gap measurement of filled twist nematic liquid crystal displays by a phase compensation method," J. Appl. Phys. 69, 1304-1309 (1991).
[CrossRef]

S. T. Tang and H. S. Kwok, "Transmissive liquid crystal cell parameters measurement by spectroscopic ellipsometry," J. Appl. Phys. 89, 80-85 (2001).
[CrossRef]

J. S. Chae and S. G. Moon, "Cell parameter measurement of a twist-nematic liquid crystal cell by the spectroscopic method," J. Appl. Phys. 95, 3250-3254 (2004).
[CrossRef]

S. T. Tang and H. S. Kwok, "Measurement of reflective liquid crystal displays," J. Appl. Phys. 91, 8950-8953 (2002).
[CrossRef]

J. Info. Displays (1)

H. Kim, J. Song, S. Park, J. Lyu, J. Souk, and K. Lee, "PVA technology for high performance LCD monitors," J. Info. Displays 1, 3-8 (2000).

J. Phys. D (1)

C. H. Gooch and H. A. Tarry, "The optical properties of twisted nematic liquid crystal structure with twisted angle 90°," J. Phys. D 8, 1575-1584 (1975).
[CrossRef]

Jpn. Display (1)

R. Kiefer, B. Webber, F. Windscheid, and G. Baur, "In-plane switching of nematic liquid crystals," Proc. Jpn. Display , 547-550 (1992).

Jpn. J. Appl. Phys. (2)

Y. Zhou, Z. He, and S. Sato, Jpn. J. Appl. Phys. , Part 1 36, 2760-2764 (1997).
[CrossRef]

J. S. Gwag, S. H. Lee, K.-Y. Han, J. C. Kim, and T.-H. Yoon, "Novel cell gap measurement method for a liquid crystal cell," Jpn. J. Appl. Phys. 41, L79-L82 (2002).
[CrossRef]

SID Symp. Digest (2)

A. Takeda, S. Kataoka, T. Sasaki, H. Chida, H. Tsuda, K. Ohmuro, T. Sasabayashi, Y. Koike, and K. Okamoto, "A super-high image quality multi-domain vertical alignment LCD by new rubbing-less technology," SID Symp. Digest 1077-1080 (1998).
[CrossRef]

W.-K. Choi, "Reflective liquid-crystal cell-gap measurement using input-polarization-angle dependence," SID Symp. Digest 33, 530-533 (2002).
[CrossRef]

Other (1)

P. Yeh and C. Gu, Optics of Liquid Crystal Display (Wiley, 1999), Chap. 4.

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Figures (5)

Fig. 1
Fig. 1

(Color online) Orientation of the polarizer axes. The LC directors of a TN-LCD are on the xy plane. The x axis is chosen along the entrance of the LC director. (a) Transmission axis of the entrance polarizer at the angle of θ, which is a variable relative angle. (b) Exit LC director at the twist angle of Φ. The transmission axis of the exit polarizer is at an angle γ from the entrance polarizer. The reflectance and the transmission are both maximal at the azimuthal angle of θ max = α .

Fig. 2
Fig. 2

(Color online) Setup for measuring the reflectance and the transmittance of a TN-LC cell. P, polarizer; A, analyzer; D, detector; BS, beam splitter; LS, laser light source. The mirror is inserted to measure the reflectance. After the reflectance has been measured, the mirror is removed to measure the transmittance.

Fig. 3
Fig. 3

(Color online) Data reveals the reflectance and the transmittance of a 90° right-TN-LC cell. The solid line indicates that the reflectance varies with the angle between the entrance polarizer and the front director, at angles of rotation from 0 to 2 π (π to 2 π not shown). The dotted line indicates that the transmittance varies with the angle between the exit analyzer and the rear director. The wavelengths of the incident light are (a) 632 and (b) 532   nm . The cell gap and the twist angle are estimated to be 5 .96   μm and 90.1°, respectively.

Fig. 4
Fig. 4

(Color online) Reflectance and transmittance of a 90° left-TN-LC cell corresponding to the incident light of wavelengths (a) 632 and (b) 532   nm . The cell gap and the twist angle are estimated as 5 .98   μm and 89.5°, respectively.

Fig. 5
Fig. 5

(Color online) Solid and dotted lines represent the reflectance of a LC cell without and with an external voltage of 0.5V, respectively. The left or right shift in the azimuth angle of R max reveals a left or right twist of the TN-LCD cell as the small voltage is applied. (a) R max is shifted to the right side (higher angle in the horizontal axis), and the liquid-crystal molecule exhibits right twist. (b) Left shift, corresponding to a left twist.

Tables (1)

Tables Icon

Table 1 Measured Cell Gap and Twist Angle of a TN-LC Cell a

Equations (8)

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

R = [ cos 2 X + Φ 2 sin 2 X X 2 Γ 2 4 sin 2 X X 2 ] 2 + { Γ sin X X [ cos 2 θ cos X + sin 2 θ Φ sin X X ] } 2 ,
R min = [ cos 2 X + Φ 2 sin 2 X X 2 ( X 2 Φ 2 ) sin 2 X X 2 ] 2 ,
tan 2 θ min = X Φ 1 tan X ,
tan 2 θ max = Φ X tan X .
T = cos 2 ( α + β ) { cos 2 X cos 2 α cos 2 β [ Φ X tan X tan 2 α ] [ Φ X tan X + tan 2 β ] } ,
tan 2 α = Φ X tan X .
tan 2 α = γ + 2 α X tan X ,
R min cos 4 2 α = ( cos 2 X + sin 2 2 α ) 2 .

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