* Sharp Laboratories of Europe, Ltd.
Abstract
New three dimensional (3D) displays switching electrically between 2D and 3D modes are discusd. The principles of operation and design considerations for particular applications are described.
Introduction
A display is prented that can be electrically
switched between an autostereoscopic (no glass) 3D
mode and a full resolution 2D mode. This 2D/3D
display can be ud in a range of products from
computer monitors to mobile displays. There are
many applications including 3D games, amument,
image capture and display. The 2D mode allows the
brush怎么读ur to enjoy the same performance as current
sacred
displays, with the added advantage of 3D for
enhanced reality and enjoyment.
In September 2002, Sharp announced mass
manufacture of electrically switchable 2D/3D
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displays. The first product was launched in November
2002: a 2.2" 2D/3D mobile phone for NTT DoCoMo
(SH251iS).1. History
In 1992, SLE began rearching 3D displays - an exciting new application that added to Sharp's high quality Liquid Crystal Displays.The first systems 1)comprid two standard LCDs mounted at 90 with beam combining optics to nd the image from one LCD to one eye and the image from the cond LCD to the cond eye. However, this particular t-up was too large and probably too expensive for the mass market. In 1994 we achieved our first single-panel 3D display 2)bad on the parallax barrier method 3). The displays were called "3D-only displays" since the 3D effect was pe
rmanent. The displays allowed a single ur to enjoy 3D from certain positions. This technology was improved in 1996 with the invention of the "sweet spot indicator" to help the ur find the best 3D viewing position. This indicator is one of the key distinguishing factors of Sharp's 3D technology 4).
Up until 1997, the 3D displays were not suitable for conventional 2D applications since only 3D images
2D/3D Switchable Displays
Adrian Jacobs *Jonathan Mather *Robert Winlow *David Montgomery *Graham Jones *
Morgan Willis *Martin Tillin *Lyndon Hill *Marina Khazova *Heather Stevenson *Grant Bourhill *Fig. 1SH251iS Mobile phone with 2D/3D display.
Fig. 3 Parallax barrier display. Fig. 4Viewing distance calculation.
achieved by u of a patterned retarder parallax barrier
and removable polarir5). The switching is achieved
mechanically by the addition of a condary polarir.
This mechanical switching is ideal for low-cost
application, but may be impractical for others.
Electrical switching can be achieved by the addition of a
component that can rotate the polarisation of light (3D)
or leave it unaffected (2D). This additional component
市场部英文could be a simple liquid crystal cell. A possible
configuration is shown in Fig. 5.
In 2D mode, the two columns of the patterned retarder
Fig. 5 Display configuration. parallax barrier transmit equally. Importantly, the 2D
image quality is the same as a standard LCD panel. In 3D mode, one column of the patterned retarder parallax barrier transmits and the other column is opaque, resulting in a 3D mode.
Other aspects of the design depend on the particular application. For example, the same 3D effect can be achieved with a parallax barrier at the rear of the display (between backlight and LCD) rather than at the front (between LCD and ur). This rear parallax barrier arrangement is uful for "Advanced TFT" transflective displays that operate in both transmissive and reflective modes. With a rear parallax barrier, the reflected brightness is identical to a standard 2D display. The transmitted brightness is reduced. With a front parallax barrier, both the reflected and transmitted brightness would be reduced.
3. The road to production
In late 2001 the electrically switched 2D/3D technology was shown to Sharp's Communications Systems Group, who wanted to integrate 3D into future mobile phones. A key to commercial success was the detailed discussion that followed, where the possible technical options were compared with detailed understanding of customer's requirements. In keeping with Sharp's history of high quality "only-one" products, a higher risk but higher performance option was chon.
A very successful and intensive collaboration followed between CSG, SLE and Sharp's Mobile LCD Group, responsible for mass manufacturing the displays. SLE made initial prototypes of 2" displays a
nd then improved the design and performance. Additionally, a number of "test" displays were created to help Mobile LCD group define manufacturing tolerances.
At this stage the only 3D displays that had been produced were "hand-made" prototypes built at SLE. The design and processing knowledge had to be transferred to Mobile LCD group, with the aim of tting-up a mass manufacturing line.
In order to be "first to market", a challenging target of 9 months was t to complete this knowledge transfer. To help the information flow between SLE and Mobile LCD BG, two rearchers from SLE spent 9 months in Sharp Tenri working cloly with colleagues from Mobile LCD BG. This 9-month visit was a key part of the successful commercialisation.
拉瓦尔The commercialisation included replicating the SLE fabrication route in J apan. Once all production problems had been overcome, the next step was to decrea the production cost, and increa the yield. For example, veral chemicals are needed to make the parallax barriers. Cost and time reduction in mass manufacture is possible using chemicals that can be applied in the manufacture of both LCDs and parallax barriers. SLE and Mobile LC BG continue to investigate novel process that will simplify manufacture. SLE benefited greatly from spending 9 months at Sharp Tenri by understanding the methods and constraints
good health
of mass manufacture. This will help us to better consider business group constraints and needs when deciding future IP.
4. 3D contents
The Sharp 2D/3D display is an integrated system - software is as important as the hardware for good 3D.Alongside the hardware development, a key part of the rearch at SLE has been understanding and developing protocols to allow comfortable 3D. The protocols control the depth in images. The depth information for the protocols comes from veral Human Factors studies commissioned by SLE.
Another important area for content generation is 3D image capture from stereo digital photography. One approach is to have a single camera with two nsors. Another approach is to have a single camera/nsor and a prism adapter to produce two views. Yet another approach is a single camera mounted on a sliding rail to capture two images. Another alternative approach is to take two parate images with a single camera and then apply software correction of image errors. All the approaches are part of SLE's current and future activities in this area.
5. Future challenges
The immediate future should involve the extension of
the electrically switching technology to a wider range
of applications. For example, it can be effectively
applied to larger area displays such as computer
monitors (Fig. 6)
For future rearch, there are many possible advances
to widen the appeal of Sharp's 2D/3D displays.
For example, we will aim to widen the position in
which a 3D image can be viewed and therefore
increa viewing freedom. This is particularly
magna
important for gaming applications. Additionally, we
will aim to develop a method for efficient 3D image
capture. New manufacturing process will be
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examined to develop cheaper, easier to produce components.
A further target will be to allow multiple viewers to
e the effect at the same time. This would be a key requirement towards the ultimate goal of 3D LCTV .Conclusions
A display system has been developed and described that allows simple switching between a full resolution,full colour 2D mode and a high quality, comfortable, no-glass 3D mode.
Clo collaboration between rearch and business groups lead to a successful commercialisation of a new technology. The future rearch in 3D involves 3D image capture and development of a system with enhanced "look-around" capability.
Acknowledgements面试常用英语
The authors would like to acknowledge the strong support and collaboration provided by members of
Fig. 63D computer monitor.
有道英译中Mobile LCD Group and Communications Systems Group during the commercialisation of this technology. We would also like to thank Corporate R&D for their continuing support and belief in our work. References
1) "New Autostereoscopic Display System", Ezra et al. SPIE V ol. 2409 February 1995
2) "Flat Panel Autostereoscopic Displays - Characterisation and enhancement", Woodgate et al. SPIE V ol 3957, January 2000.
3) "Autostereoscopic Displays - Past and Future", GB Kirby Meacham, SPIE V ol 624, 1986.
4) "Autosteroscopic Display" GJ Woodgate et al. US Patent Application US6055013
5) "3D display Systems Hardware Rearch at SLE: an update", J acobs et al. Sharp Technical J ournal August 1999.
6) Sharp Laboratories of Europe, Ltd.
URL:www.uk
E-mail :uk
received Jan. 14, 2003
