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A Handheld projector (also known as a pocket projector, mobile projector, pico projector or mini beamer) is technology that applies the use of an image projector in an handheld device. It is a response to the emergence/development of compact portable devices such as mobile phones, personal digital assistants, and digital cameras, which have sufficient storage capacity to handle presentation materials but little space to accommodate an attached display screen. Handheld projectors involve miniaturized hardware and software that can project digital images onto any nearby viewing surface.
The system comprises five main parts: the battery; the electronics; the laser or led light sources; the combiner optic; and in some cases, scanning mirrors. First, the electronics system turns the image into an electronic signal. Next, the electronic signals drive laser or led light sources with different colors and intensities down different paths. In the combiner optic, the different light paths are combined into one path, defining a palette of colors. Finally, in some technologies the mirrors copy the image pixel-by-pixel and can then project the image. Other optical systems do not use the "mirrors" technology, and are considered more robust. This entire mirror system is compacted into one very tiny chip. An important design characteristic of a handheld projector is the ability to project a clear image, regardless of the physical characteristics of the viewing surface.
Major advances in imaging technology have allowed the introduction of hand-held (pico) type video projectors. The concept was demonstrated in Australia in 1998 when a small projector, literally housed in a matchbox for effect, was shown to potential investors by Digislide. The concept was also introduced by Explay in 2003 to various consumer electronics players. Their solution was publicly announced through their relationship with Kopin in January 2005.
The first public showcase was by Digislide at the ANZA tech conference in October 2006, and Digislide went on to win awards from industry, commerce and governments, including Winner “ANZA Hottest Technology Award” 2005; "Top 100 Global Innovator” Guidewire Group, 2006; Finalist World Technology Awards (IT Hardware) 2006; Winner Secrets of Australian ICT Innovation 2006; Finalist Hong Kong Australia Business Awards 2007; Nominee for Wall Street Journal’s Asia Pacific Innovation Award Sept 2007; Innovator of The Year-Handheld Projection Technologies, Frost and Sullivan Hand Held Projection (Singapore) 2009; iAWARD (State Winner) for Leisure and Media, July 2010; and iAWARD (Finalist and National Merit Recognition) for Leisure and Media, August 2010.
. Insight Media market research has divided the leading players in this application into various categories:
- micro-display makers (e.g., TI's DLP, Himax, Micron / Displaytech and Syndiant LCoS, Maradin, Microvision, Lemoptix and bTendo MEMS scanners)
- light source makers (e.g., Lumileds, Osram, Cree LEDs and Corning, Nichia, Mitsubishi Lasers
- module makers (e.g., Jabil/Sypro Digital Light Processing (DLP) with LED, 3M Liquid crystal on Silicon (LCoS) with LED, Explay LCoS with laser)
Manufacturers have produced handheld projectors exhibiting high-resolution, good brightness, and low energy consumption in a slightly larger format than pico. However, most LED projectors of the current pico size up til May 2009 had been widely criticized for having insufficient brightness for everyday use in a normally lit room.
In 2011, Texas Instruments DLP announced improved chip sets that enable brighter images, and LED advances were such that pico projectors using that technology were also increasing in brightness. The DLP chip sets are designed to enhance image brightness without increasing power usage for both WVGA (native DVD resolution) devices, such as mobile phones, and VGA devices, such as digital cameras and camcorders. The chip sets have the ability to project an image up to 50 inches (1,300 mm) (1270 mm) on any surface in optimum lighting conditions. The tiny projection chip requires very little space and is virtually undetected in a device's overall form factor. With advancements in size and performance, the TI DLP Pico chipset supplies big picture experiences with contemporary handsets..
Other developers, including Digislide and IBM, have been designing and developing alternative solutions using laser technologies. Concentration of effort is in reducing or removing "laser speckle" and "noise." Digislide is pursuing both static and dynamic solutions.
- Texas Instruments's Digital Light Processing (DLP)
- Microvision's beam-steering
- a handful of LCoS (Liquid crystal on silicon) manufacturers including Syndiant, Himax, Micron Technologies and Omnivision supply companies including Digislide for both their LED and laser solutions.
Most micro projectors employ one of these imagers, combined with color-sequential (RGB) LEDs in either a single or triple architecture format. Manufacturers that have adopted this technology include Digislide, Foryou MP-315(LCoS), Optoma's PK201 / PK301 (DLP), 3M's MPro 160 / 180 (LCoS), Aiptek's V50 (DLP), AAXA's M2 (LCoS), Bonitor MP302 (LCos), Micron's PoP Video (LCoS), and Vivitek's High Definition Qumi (DLP). Some older models incorporated a single LCoS imager chip with single white LED which is recognized to offer lower cost, high resolution, and fast response at the expense of color quality. Other models such as the Dell M109S employed a color wheel plus white LED technology which improves color quality but generally requires a larger form factor. Other micro projectors such employ RGB laser technology such as Microvision's beam-steering plus laser technology and AAXA's laser plus LCOS technology.
The advantages and disadvantages of each technology vary. For example, while DLP typically has slightly lower resolution than their LCoS counterparts due to the tiny mirrors used in DLP technology, 3-LED DLP projectors are generally regarded as having a higher contrast, better efficiency and lower power consumption as opposed color-sequential LCoS units and better color quality than white LED LCoS units. LED technologies however are generally regarded as more robust or "ruggedised". Laser scanning projectors such as Microvision's ShowX and AAXA's L1 offer very good color gamut and low power consumption due to the use of lasers as the light source and also present an image that is always in focus. However, high speckle noise along with thermal instability in the image remains a major challenge, primarily due to the pumped green laser. The new "Direct Green Laser" (DGL) technologies that replace the "pumped green laser" in next generation Laser scanning projectors, in combination with improved hardware optics, MEMS Mirror designs and other operational methods are being deployed or are under development. Speckle noise should be reduced significantly, plus greatly improve thermal issues and reduce power consumption even further.
Digislide's Digismart Miniature Projection Technologies™ project is designed around the Spectralus’ green laser and the Syndiant LCOS panel. Digislide has two solutions for removing "speckle" one is a dynamic solution and the other a static solution. The joint development partner, Spectralus, is one of the global leaders in the field of compact and super-efficient green lasers optimized for the projection and display applications. Spectralus’ patented laser technology is scalable and Spectralus has developed a road map for high power laser sources.
Handheld projector can be used for different applications than small conventional projectors. Since 2008 researchers are studying applications that are specifically designed for handheld projectors often using prototypes of mobile phones with an integrated projector. In October, 2007, Digislide demonstrated alpha prototypes of its embedded projectors within a laptop, games consoles and GPS devices and in 2008 to both industry and government bodies. Digislide demonstrated an embedded projector in a Haier Laptop, as a joint development with Haier at the Qindao, CES Expo in Shandong Province, China.
Recent mobile phones have the ability to store thousands of photos and can be used to take photos with resolutions up to several megapixels. Viewing the photos is restricted by the phones' small displays. Projector phones allow photographs to be shared with a larger audience. One study found that people preferred to view and share photos with projector phones, compared to using conventional mobile phones. The projected display allowed viewing of pictures by all present which is currently not possible using a single mobile device. Furthermore, people enjoyed looking at and talking together about the pictures.
Handheld projectors, in particular projector phones, could offer new possibilities for mobile gaming, as demonstrated by the adaptation of the PlayStation 3 game LittleBigPlanet. Digislide has developed the WeSii "Home Theatre in Your Hand" which sets the Wii free from the TV. WeSii won two iAwards in Australia in 2010. WeSii™ is a dockable/decoupable projector and audio system that enables the Nintendo Wii™ to travel anywhere you want to go. An infrared curtain has been designed into the WeSii™ audio system, so there’s no need for the fragile Wii™ sensor bar to travel. Furthermore, the WeSii™’s infrared curtain has an expanded capacity, allowing individual players to spread further out and use more physicality in their game. WeSii is truly convergent, allowing interface with The dockable projector can be popped in a pocket or purse, and interfaced with iPOD™, iPHONE™, smart phones with TV functionality; laptops or notebooks,Sony’s suite of Playstation™ products, Microsoft’s XBox360™, Nintendo DS™, DVD players, Digital cameras; and any visual display product with composite video output. With a set top box interfaced, it provides mobile large scale TV reception with good quality sound.
In Players can sketch a world on a sheet of paper or use an existing physical configuration of objects and let the physics engine simulate physical procedures in this world to achieve game goals.
Hand gesture recognition
Size reduction of mobile devices is often limited by the size of the used display. Apart from the display a complete phone can be, for example, integrated in a headset. It has been demonstrated that pico projectors integrated in headsets could be used as interaction devices, e.g., using additional hand and finger tracking. The MIT Media Lab proposed a wearable gestural interface device named SixthSense. Chris Harrison developed a working system called Omnitouch. Finally, the Light Blue Optics Light Touch is yet another similar device. Lisa Cowan from UCSD showed a proof of concept of gesture recognition using shadow-occluding of the projector, called ShadowPuppets. A modified laser projector has been used to perform gesture recognition and finger tracking using laser-based active tracking techniques at the University of Tokyo (Smart Laser Scanner and Laser Sensing Display).
Pointer-based computer control
Combining a pico projector with a webcam, a laser pointer, and image processing software enables full control of any computing system via the laser pointer. Pointer on/off actions, motion patterns (e.g., dwell, repetitive visit, circles, etc.) and more can all be mapped to events which generate standard mouse or keyboard events, or user-programmable actions.
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- "Kopin Team up with Explay to Develop Nano-Projector Engine". 2005-01-04.
- Brennesholtz 2008, p.84.
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- Light Blue Optics Light Touch
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- Brennesholtz, M (2008). "Market Segment Analysis: Pico-Projectors", Insight Media