Dual-view integral imaging 3D display using polarizer parallax barriers Fei Wu,1,2 Qiong-Hua Wang,1 Cheng-Gao Luo,1 Da-Hai Li,1 and Huan Deng1,* 1 2
School of Electronics and Information Engineering, Sichuan University, Chengdu 610065, China
Department of Communication Engineering, Chengdu Technological University, Chengdu 611730, China *Corresponding author: [email protected] Received 9 January 2014; revised 15 February 2014; accepted 16 February 2014; posted 19 February 2014 (Doc. ID 204405); published 25 March 2014
We propose a dual-view integral imaging (DVII) 3D display using polarizer parallax barriers (PPBs). The DVII 3D display consists of a display panel, a microlens array, and two PPBs. The elemental images (EIs) displayed on the left and right half of the display panel are captured from two different 3D scenes, respectively. The lights emitted from two kinds of EIs are modulated by the left and right half of the microlens array to present two different 3D images, respectively. A prototype of the DVII 3D display is developed, and the experimental results agree well with the theory. © 2014 Optical Society of America OCIS codes: (230.0230) Optical devices; (110.0110) Imaging systems. http://dx.doi.org/10.1364/AO.53.002037
1. Introduction
A multiview display presents multiple images to multiple observers viewing from different viewing directions. For example, in a car, the multiview display presents live traffic information to the driver and meanwhile presents an entertainment reality show to a passenger sitting in the co-pilot position. By presenting different information in different viewing directions, the multiview display satisfies different observers’ requirements simultaneously. The multiview display has been implemented by use of a display panel and additional parallax barrier or lenticular lens array [1–3]. Recently, a few methods using a single display panel have been proposed to realize the multiview display [4,5]. A dual-view liquid crystal display fabricated by patterned electrodes is proposed by use of spatial-multiplexed technique. The main pixel in the dual-view liquid crystal display is composed of a left subpixel and a right subpixel, which have the opposite rotation directions. Two different images are presented to different observers who are viewing at different directions. A blue phase liquid crystal combined with 1559-128X/14/102037-03$15.00/0 © 2014 Optical Society of America
a directional backlight module realizes the dual-view display by use of time-multiplexed technique. By controlling the light sources and image data, the timemultiplexed dual-view display displays two different images to different observers sequentially. These methods present only 2D images to the observers. Integral imaging (II) display, which was first proposed by Lippmann in 1908, is regarded as a promising 3D display [6–9]. Recently, we have proposed a dual-view integral imaging (DVII) 3D display [10]. It presents two different 3D images in the left and right viewing directions, respectively. However, the narrow viewing angle limits the applications of the DVII 3D display. So we propose a spatial-multiplexed DVII 3D display with polarizer parallax barriers (PPBs) to improve the viewing angle. 2. Principle and Structure
Figure 1 illustrates the principle and structure of the DVII 3D display. It consists of a display panel, a microlens array and two PPBs. PPB 1 is in front of the display panel, and PPB 2 is in front of the microlens array. The centers of PPB 1, PPB 2, the display panel, and the microlens array are aligned. As shown in Fig. 1, the number of the elemental images (EIs) in the horizontal direction is even, and the number of the microlenses in the horizontal direction is 1 April 2014 / Vol. 53, No. 10 / APPLIED OPTICS
2037
Right f
L
P p Right-view II area REIs
θ
LEIs Left-view II area
Micro-lens array
Display panel
PPB 2
PPB 1
Left
Fig. 1. Principle and structure of the DVII 3D display.
one less than that. The number and size of the units in PPB 1 are equal to those of the EIs, and the number and size of the units in PPB 2 are equal to those of the microlenses. Two kinds of diagonals in Fig. 1 represent horizontal and vertical polarization directions of the image light, respectively. The central unit of PPB 2 consists of two parts with perpendicular polarization directions, whereas other units of PPB 1 and PPB 2 have only horizontal or vertical polarization directions. The polarization directions between adjacent units of PPB 1 and PPB 2 are perpendicular. The EIs displayed on the left and right half of the display panel are denoted as left elemental images (LEIs) and right elemental images (REIs), respectively. The LEIs and REIs are captured from two different 3D scenes, respectively. The lights emitted from the LEIs are modulated by the left half of the microlens array and propagated to reconstruct a 3D image in the right-view area, whereas the lights emitted from the REIs are modulated by the right half of the microlens array and propagate to the reconstruct another 3D image in the left-view area. Thus two different 3D images are simultaneously obtained in the left-view and right-view II 3D displays. Suppose that L is the optimal viewing distance between the microlens array and the observers and P is the pitch of the EI. f and p are the focal length and the pitch of the microlens, respectively. Based on the geometric relationships in Fig. 1, the optimal viewing distance L is shown as [10] Pf : (1) P−p As shown in Fig. 1, when the viewing distance between the microlens array and the observers is smaller than L, the viewing angle of each II display is decreased, whereas when the viewing distance is larger than L, a flipping area appears between the left-view and right-view areas. Since the dual-view L
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3D display is usually used in a car, the positions of the DVII 3D display and the front seats are fixed. Therefore the distance between the DVII 3D display and the front seats is fixed as L. From Eq. (1), we can see that the DVII 3D display can satisfy different needs by adjusting P, p, and f . At the optimal viewing distance, the viewing angle of each II 3D display θ is obtained as P : (2) θ arctan f The viewing angle of each II 3D display in previous DVII θ0 is expressed as [11] MP ; arctan 2M − 1f
θ0
(3)
where M is the number of the EIs in the horizontal directions, and it is a positive integer. It is obvious that the viewing angle of the DVII 3D display is enhanced by use of PPBs. 3. Experimental Results
We developed a prototype of the DVII 3D display using a pinhole array to replace the microlens array. In our experiment, a backlight unit and film were combined as a display panel with high resolution, and the film was stuck well on PPB 1. Another film was used as the pinhole array of the DVII 3D display and was stuck well on PPB 2. Each PPB is composed of a striped half-wave plate, a diffusion screen, and a striped polarizer [12]. The EIA of DVII 3D display has 60 × 30 EIs, and an EI of the EIA has 60 × 60 pixels. A pinhole has 59 × 60 pixels, and the aperture of a pinhole has 5 × 6 pixels. The parameters of the prototype are shown in Table 1. The LEIs and REIs of the DVII 3D display were captured from two different scenes in a computer.
Table 1.
Specifications Values
Parameters of the Prototype
P mm
f mm
L mm
2.52
3.6
216
The 3D scene for the left-view area of the DVII 3D display includes two “S” letters, and the 3D scene of the right-view area of the DVII 3D display includes two “C” letters. The left letter of each scene is located 40 mm in front of the display panel, while the right letter of each scene is located 50 mm behind the display panel, respectively. By use of MATLAB software, the EIA of the DVII 3D display was generated, as shown in Fig. 2. Corresponding to the parameters of the DVII 3D display, theoretical viewing angle of each II 3D display is 35° at the optimal viewing distance. However, in practice, the pinhole is used to replace the microlens, which is not an ideal point. Therefore, the viewing areas of the left-view and right-view II 3D displays are slightly decreased, and the practical viewing angle of each II 3D display is 30° [13]. When the viewing angle is 33° to the left, the two “S” letters are restructured in the left-view area of the DVII 3D display, as shown in Fig. 3(a). Decreasing the viewing angle to 3° to the left, the relative positions of the two “S” letters are changed, as shown in Fig. 3(b). When the viewing angle is 3° to the right, the two “C” letters are seen in the right-view area of the DVII 3D display, as shown in Fig. 3(c). Increasing the
Fig. 2. EIA of the DVII 3D display.
(a) 33° to the left
(b) 3° to the left
(c) 3° to the right
(d) 33° to the right
Fig. 3. 3D images viewed from different angles in the DVII 3D display. (a) 33° to the left. (b) 3° to the left. (c) 3° to the right. (d) 33° to the right.
viewing angle to 33° to the right, the relative positions of the two “C” letters are also changed, as shown in Fig. 3(d). Therefore two different 3D images are simultaneously obtained in the leftand right-viewing directions. 4. Conclusion
A spatial-multiplexed DVII 3D display using PPBs is proposed. It consists of a display panel, a microlens array, and two PPBs. The EIs on the left and right half of the display panel are captured from two different 3D scenes, respectively. By use of two PPBs, the lights emitted from LEIs and REIs are modulated by the left and right half of the microlens array, respectively. A prototype of the DVII 3D display is developed, and two different 3D images are simultaneously obtained in the left and right viewing directions. It has great potential application in 3D displays. Moreover, the optimal viewing distance cannot be adjusted to satisfy the observers in realtime. It would be studied in our future research. The work is supported by the “973” Program under grant no. 2013CB328802, the NSFC under grant nos. 61320106015 and 61225022, and the “863” Program under grant nos. 2012AA011901 and 2012AA03A301. References 1. D. U. Kean, D. J. Montgomery, G. Bourhill, and J. Mather, “Multiple view display,” U.S. patent 7154653B2 (December26, 2006). 2. M. P. C. M. Krijn, S. T. De Zwart, D. K. G. De Boer, O. H. Willemsen, and M. Sluijter, “2-D/3-D displays based on switchable lenticulars,” J. Soc. Inf. Disp. 16, 847–855 (2008). 3. C. P. Chen, J. H. Lee, T. H. Yoon, and J. C. Kim, “Monoview/ dual-view switchable liquid crystal display,” Opt. Lett. 34, 2222–2224 (2009). 4. C. T. Hsieh, J. N. Shu, H. T. Chen, C. Y. Huang, C. J. Tian, and C. H. Lin, “Dual-view liquid crystal display fabricated by patterned electrodes,” Opt. Express 20, 8641–8648 (2012). 5. J. P. Cui, Y. Li, J. Yan, H. C. Cheng, and Q. H. Wang, “Time-multiplexed dual-view display using a blue phase liquid crystal,” J. Disp. Technol. 9, 87–90 (2013). 6. Lippmann, “La photographie integrale,” C. R. Acad. Sci. 146, 446–451 (1908). 7. H. Kim, J. Hahn, and B. Lee, “The use of a negative index planoconcave lens array for wide-viewing angle integral imaging,” Opt. Express 16, 21865–21880 (2008). 8. D. H. Shin, C. W. Tan, B. G. Lee, J. J. Lee, and E. S. Kim, “Resolution-enhanced three-dimensional image reconstruction by use of smart pixel mapping in computational integral imaging,” Appl. Opt. 47, 6656–6665 (2008). 9. C. C. Ji, C. G. Luo, H. Deng, D. H. Li, and Q. H. Wang, “Tilted elemental image array generation method for Moiré-reduced computer generated integral imaging display,” Opt. Express 21, 19816–19824 (2013). 10. H. Deng, Q. H. Wang, L. Li, and D. H. Li, “An integral-imaging three-dimensional display with wide viewing angle,” J. Soc. Inf. Disp. 19, 679–684 (2011). 11. F. Wu, H. Deng, C. G. Luo, D. H. Li, and Q. H. Wang, “Dualview integral imaging three-dimensional display,” Appl. Opt. 52, 4911–4914 (2013). 12. Q. H. Wang, Y. T. Tao, W. X. Zhao, and D. H. Li, “A full resolution autostereoscopic 3D display based on polarizer parallax barrier,” Chin. Opt. Lett. 8, 373–374 (2010). 13. F. Wu, H. Deng, D. H. Li, and Q. H. Wang, “High-opticalefficiency integral imaging display based on gradientaperture pinhole array,” Opt. Eng. 52, 054002 (2013). 1 April 2014 / Vol. 53, No. 10 / APPLIED OPTICS
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School of Electronics and Information Engineering, Sichuan University, Chengdu 610065, China
Department of Communication Engineering, Chengdu Technological University, Chengdu 611730, China *Corresponding author: [email protected] Received 9 January 2014; revised 15 February 2014; accepted 16 February 2014; posted 19 February 2014 (Doc. ID 204405); published 25 March 2014
We propose a dual-view integral imaging (DVII) 3D display using polarizer parallax barriers (PPBs). The DVII 3D display consists of a display panel, a microlens array, and two PPBs. The elemental images (EIs) displayed on the left and right half of the display panel are captured from two different 3D scenes, respectively. The lights emitted from two kinds of EIs are modulated by the left and right half of the microlens array to present two different 3D images, respectively. A prototype of the DVII 3D display is developed, and the experimental results agree well with the theory. © 2014 Optical Society of America OCIS codes: (230.0230) Optical devices; (110.0110) Imaging systems. http://dx.doi.org/10.1364/AO.53.002037
1. Introduction
A multiview display presents multiple images to multiple observers viewing from different viewing directions. For example, in a car, the multiview display presents live traffic information to the driver and meanwhile presents an entertainment reality show to a passenger sitting in the co-pilot position. By presenting different information in different viewing directions, the multiview display satisfies different observers’ requirements simultaneously. The multiview display has been implemented by use of a display panel and additional parallax barrier or lenticular lens array [1–3]. Recently, a few methods using a single display panel have been proposed to realize the multiview display [4,5]. A dual-view liquid crystal display fabricated by patterned electrodes is proposed by use of spatial-multiplexed technique. The main pixel in the dual-view liquid crystal display is composed of a left subpixel and a right subpixel, which have the opposite rotation directions. Two different images are presented to different observers who are viewing at different directions. A blue phase liquid crystal combined with 1559-128X/14/102037-03$15.00/0 © 2014 Optical Society of America
a directional backlight module realizes the dual-view display by use of time-multiplexed technique. By controlling the light sources and image data, the timemultiplexed dual-view display displays two different images to different observers sequentially. These methods present only 2D images to the observers. Integral imaging (II) display, which was first proposed by Lippmann in 1908, is regarded as a promising 3D display [6–9]. Recently, we have proposed a dual-view integral imaging (DVII) 3D display [10]. It presents two different 3D images in the left and right viewing directions, respectively. However, the narrow viewing angle limits the applications of the DVII 3D display. So we propose a spatial-multiplexed DVII 3D display with polarizer parallax barriers (PPBs) to improve the viewing angle. 2. Principle and Structure
Figure 1 illustrates the principle and structure of the DVII 3D display. It consists of a display panel, a microlens array and two PPBs. PPB 1 is in front of the display panel, and PPB 2 is in front of the microlens array. The centers of PPB 1, PPB 2, the display panel, and the microlens array are aligned. As shown in Fig. 1, the number of the elemental images (EIs) in the horizontal direction is even, and the number of the microlenses in the horizontal direction is 1 April 2014 / Vol. 53, No. 10 / APPLIED OPTICS
2037
Right f
L
P p Right-view II area REIs
θ
LEIs Left-view II area
Micro-lens array
Display panel
PPB 2
PPB 1
Left
Fig. 1. Principle and structure of the DVII 3D display.
one less than that. The number and size of the units in PPB 1 are equal to those of the EIs, and the number and size of the units in PPB 2 are equal to those of the microlenses. Two kinds of diagonals in Fig. 1 represent horizontal and vertical polarization directions of the image light, respectively. The central unit of PPB 2 consists of two parts with perpendicular polarization directions, whereas other units of PPB 1 and PPB 2 have only horizontal or vertical polarization directions. The polarization directions between adjacent units of PPB 1 and PPB 2 are perpendicular. The EIs displayed on the left and right half of the display panel are denoted as left elemental images (LEIs) and right elemental images (REIs), respectively. The LEIs and REIs are captured from two different 3D scenes, respectively. The lights emitted from the LEIs are modulated by the left half of the microlens array and propagated to reconstruct a 3D image in the right-view area, whereas the lights emitted from the REIs are modulated by the right half of the microlens array and propagate to the reconstruct another 3D image in the left-view area. Thus two different 3D images are simultaneously obtained in the left-view and right-view II 3D displays. Suppose that L is the optimal viewing distance between the microlens array and the observers and P is the pitch of the EI. f and p are the focal length and the pitch of the microlens, respectively. Based on the geometric relationships in Fig. 1, the optimal viewing distance L is shown as [10] Pf : (1) P−p As shown in Fig. 1, when the viewing distance between the microlens array and the observers is smaller than L, the viewing angle of each II display is decreased, whereas when the viewing distance is larger than L, a flipping area appears between the left-view and right-view areas. Since the dual-view L
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APPLIED OPTICS / Vol. 53, No. 10 / 1 April 2014
3D display is usually used in a car, the positions of the DVII 3D display and the front seats are fixed. Therefore the distance between the DVII 3D display and the front seats is fixed as L. From Eq. (1), we can see that the DVII 3D display can satisfy different needs by adjusting P, p, and f . At the optimal viewing distance, the viewing angle of each II 3D display θ is obtained as P : (2) θ arctan f The viewing angle of each II 3D display in previous DVII θ0 is expressed as [11] MP ; arctan 2M − 1f
θ0
(3)
where M is the number of the EIs in the horizontal directions, and it is a positive integer. It is obvious that the viewing angle of the DVII 3D display is enhanced by use of PPBs. 3. Experimental Results
We developed a prototype of the DVII 3D display using a pinhole array to replace the microlens array. In our experiment, a backlight unit and film were combined as a display panel with high resolution, and the film was stuck well on PPB 1. Another film was used as the pinhole array of the DVII 3D display and was stuck well on PPB 2. Each PPB is composed of a striped half-wave plate, a diffusion screen, and a striped polarizer [12]. The EIA of DVII 3D display has 60 × 30 EIs, and an EI of the EIA has 60 × 60 pixels. A pinhole has 59 × 60 pixels, and the aperture of a pinhole has 5 × 6 pixels. The parameters of the prototype are shown in Table 1. The LEIs and REIs of the DVII 3D display were captured from two different scenes in a computer.
Table 1.
Specifications Values
Parameters of the Prototype
P mm
f mm
L mm
2.52
3.6
216
The 3D scene for the left-view area of the DVII 3D display includes two “S” letters, and the 3D scene of the right-view area of the DVII 3D display includes two “C” letters. The left letter of each scene is located 40 mm in front of the display panel, while the right letter of each scene is located 50 mm behind the display panel, respectively. By use of MATLAB software, the EIA of the DVII 3D display was generated, as shown in Fig. 2. Corresponding to the parameters of the DVII 3D display, theoretical viewing angle of each II 3D display is 35° at the optimal viewing distance. However, in practice, the pinhole is used to replace the microlens, which is not an ideal point. Therefore, the viewing areas of the left-view and right-view II 3D displays are slightly decreased, and the practical viewing angle of each II 3D display is 30° [13]. When the viewing angle is 33° to the left, the two “S” letters are restructured in the left-view area of the DVII 3D display, as shown in Fig. 3(a). Decreasing the viewing angle to 3° to the left, the relative positions of the two “S” letters are changed, as shown in Fig. 3(b). When the viewing angle is 3° to the right, the two “C” letters are seen in the right-view area of the DVII 3D display, as shown in Fig. 3(c). Increasing the
Fig. 2. EIA of the DVII 3D display.
(a) 33° to the left
(b) 3° to the left
(c) 3° to the right
(d) 33° to the right
Fig. 3. 3D images viewed from different angles in the DVII 3D display. (a) 33° to the left. (b) 3° to the left. (c) 3° to the right. (d) 33° to the right.
viewing angle to 33° to the right, the relative positions of the two “C” letters are also changed, as shown in Fig. 3(d). Therefore two different 3D images are simultaneously obtained in the leftand right-viewing directions. 4. Conclusion
A spatial-multiplexed DVII 3D display using PPBs is proposed. It consists of a display panel, a microlens array, and two PPBs. The EIs on the left and right half of the display panel are captured from two different 3D scenes, respectively. By use of two PPBs, the lights emitted from LEIs and REIs are modulated by the left and right half of the microlens array, respectively. A prototype of the DVII 3D display is developed, and two different 3D images are simultaneously obtained in the left and right viewing directions. It has great potential application in 3D displays. Moreover, the optimal viewing distance cannot be adjusted to satisfy the observers in realtime. It would be studied in our future research. The work is supported by the “973” Program under grant no. 2013CB328802, the NSFC under grant nos. 61320106015 and 61225022, and the “863” Program under grant nos. 2012AA011901 and 2012AA03A301. References 1. D. U. Kean, D. J. Montgomery, G. Bourhill, and J. Mather, “Multiple view display,” U.S. patent 7154653B2 (December26, 2006). 2. M. P. C. M. Krijn, S. T. De Zwart, D. K. G. De Boer, O. H. Willemsen, and M. Sluijter, “2-D/3-D displays based on switchable lenticulars,” J. Soc. Inf. Disp. 16, 847–855 (2008). 3. C. P. Chen, J. H. Lee, T. H. Yoon, and J. C. Kim, “Monoview/ dual-view switchable liquid crystal display,” Opt. Lett. 34, 2222–2224 (2009). 4. C. T. Hsieh, J. N. Shu, H. T. Chen, C. Y. Huang, C. J. Tian, and C. H. Lin, “Dual-view liquid crystal display fabricated by patterned electrodes,” Opt. Express 20, 8641–8648 (2012). 5. J. P. Cui, Y. Li, J. Yan, H. C. Cheng, and Q. H. Wang, “Time-multiplexed dual-view display using a blue phase liquid crystal,” J. Disp. Technol. 9, 87–90 (2013). 6. Lippmann, “La photographie integrale,” C. R. Acad. Sci. 146, 446–451 (1908). 7. H. Kim, J. Hahn, and B. Lee, “The use of a negative index planoconcave lens array for wide-viewing angle integral imaging,” Opt. Express 16, 21865–21880 (2008). 8. D. H. Shin, C. W. Tan, B. G. Lee, J. J. Lee, and E. S. Kim, “Resolution-enhanced three-dimensional image reconstruction by use of smart pixel mapping in computational integral imaging,” Appl. Opt. 47, 6656–6665 (2008). 9. C. C. Ji, C. G. Luo, H. Deng, D. H. Li, and Q. H. Wang, “Tilted elemental image array generation method for Moiré-reduced computer generated integral imaging display,” Opt. Express 21, 19816–19824 (2013). 10. H. Deng, Q. H. Wang, L. Li, and D. H. Li, “An integral-imaging three-dimensional display with wide viewing angle,” J. Soc. Inf. Disp. 19, 679–684 (2011). 11. F. Wu, H. Deng, C. G. Luo, D. H. Li, and Q. H. Wang, “Dualview integral imaging three-dimensional display,” Appl. Opt. 52, 4911–4914 (2013). 12. Q. H. Wang, Y. T. Tao, W. X. Zhao, and D. H. Li, “A full resolution autostereoscopic 3D display based on polarizer parallax barrier,” Chin. Opt. Lett. 8, 373–374 (2010). 13. F. Wu, H. Deng, D. H. Li, and Q. H. Wang, “High-opticalefficiency integral imaging display based on gradientaperture pinhole array,” Opt. Eng. 52, 054002 (2013). 1 April 2014 / Vol. 53, No. 10 / APPLIED OPTICS
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