Handheld projector
Encyclopedia
A Handheld projector is an emerging technology that applies the use of an image projector
in a handheld device
. It is a response to the emergence of compact portable devices such as mobile phone
s, personal digital assistant
s, and digital camera
s, 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, such as a wall.
The system comprises five main parts: the battery, the electronics, the laser
light sources, the combiner optic, and the scanning mirrors. First, the electronics system turns the image into an electronic signal. Next the electronic signals drive laser light sources with different colors and intensities down different paths. In the combiner optic the different light paths are combined into one path demonstrating a palette of colors. Finally, the mirrors copy the image pixel-by-pixel and can then project the image. This entire 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.
s. The concept was introduced by Explay in 2003 and shown 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. Insight Media market research divided the leading players in this application into micro-display makers (e.g., TI's DLP, Himax, Micron / Displaytech and Syndiant LCoS, and Maradin, Microvision and bTendo MEMS scanners), light source makers (e.g., Lumileds, Osram, Cree LEDs and Corning, Nichia, Mitsubishi Lasers) and module makers (e.g., Jabil/Sypro DLP with LED, 3M 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 as of May 2009 have been widely criticized for having insufficient brightness for everyday use in a normally lit room.
In 2011, Texas Instruments
DLP announced improved chipset
s that enable brighter images. The chipsets 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 chipsets have the ability to project an image up to 50” 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 .
There are currently three major competing imager technologies for micro projectors. Texas Instruments's Digital Light Processing (DLP), Microvision's beam-steering, and a handful of LCoS (Liquid crystal on silicon
) manufacturers including Micron Technologies and Omnivision. 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 Optoma's PK201 / PK301 (DLP), 3M's MPro 160 / 180 (LCoS), Aiptek's V50 (DLP), AAXA's M2 (LCoS), Bonitor MP302 (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 + 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 + laser technology and AAXA's laser + 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. 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 primarily due to the pumped green laser in the image remains a major challenge.
Example of phone with a built in DLP projector: I8520 (Galaxy Beam)
, the LG eXpo Projector Phone, and the NTT DoCoMo F-04B Projector Phone.
game LittleBigPlanet
. 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.
. The MIT Media Lab is developing a wearable gestural interface device named SixthSense. Lisa Cowan from UCSD showed a proof of concept of gesture recognition using shadow-occluding of the projector. 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).
, 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.
Image projector
An image projector is an optical device that projects an image onto a surface, commonly a projection screen.Most projectors creates an image by shining a light through a small transparent image, but some newer types of projectors can project the image directly, by using lasers...
in a handheld device
Handheld device
A mobile device is a small, hand-held computing device, typically having a display screen with touch input and/or a miniature keyboard and less than . Early pocket sized ones were joined in the late 2000s by larger but otherwise similar tablet computers...
. It is a response to the emergence of compact portable devices such as mobile phone
Mobile phone
A mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...
s, personal digital assistant
Personal digital assistant
A personal digital assistant , also known as a palmtop computer, or personal data assistant, is a mobile device that functions as a personal information manager. Current PDAs often have the ability to connect to the Internet...
s, and digital camera
Digital camera
A digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor. It is the main device used in the field of digital photography...
s, which have sufficient storage capacity to handle presentation materials but little space to accommodate an attached display screen
Computer display
A monitor or display is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure...
. Handheld projectors involve miniaturized hardware and software that can project digital images onto any nearby viewing surface, such as a wall.
The system comprises five main parts: the battery, the electronics, the laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...
light sources, the combiner optic, and the scanning mirrors. First, the electronics system turns the image into an electronic signal. Next the electronic signals drive laser light sources with different colors and intensities down different paths. In the combiner optic the different light paths are combined into one path demonstrating a palette of colors. Finally, the mirrors copy the image pixel-by-pixel and can then project the image. This entire 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.
Overview
Major advances in imaging technology have allowed the introduction of hand-held (pico) type video projectorVideo projector
A video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other...
s. The concept was introduced by Explay in 2003 and shown 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. Insight Media market research divided the leading players in this application into micro-display makers (e.g., TI's DLP, Himax, Micron / Displaytech and Syndiant LCoS, and Maradin, Microvision and bTendo MEMS scanners), light source makers (e.g., Lumileds, Osram, Cree LEDs and Corning, Nichia, Mitsubishi Lasers) and module makers (e.g., Jabil/Sypro DLP with LED, 3M 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
Light-emitting diode
A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...
projectors of the current pico size as of May 2009 have been widely criticized for having insufficient brightness for everyday use in a normally lit room.
In 2011, Texas Instruments
Texas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
DLP announced improved chipset
Chipset
A chipset, PC chipset, or chip set refers to a group of integrated circuits, or chips, that are designed to work together. They are usually marketed as a single product.- Computers :...
s that enable brighter images. The chipsets are designed to enhance image brightness without increasing power usage for both WVGA
WVGA
WVGA may refer to:* Wide VGA 800×480 resolution* WVGA , a radio station licensed to Lakeland, Georgia, United States* WSWG, a television station licensed to Valdosta, Georgia, United States, which held the call sign WVGA from April 1979 to May 1994...
(native DVD resolution) devices, such as mobile phones, and VGA devices, such as digital cameras and camcorders. The chipsets have the ability to project an image up to 50” 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 .
There are currently three major competing imager technologies for micro projectors. Texas Instruments's Digital Light Processing (DLP), Microvision's beam-steering, and a handful of LCoS (Liquid crystal on silicon
Liquid crystal on silicon
Liquid crystal on silicon is a "micro-projection" or "micro-display" technology typically applied in projection televisions. It is a reflective technology similar to DLP projectors; however, it uses liquid crystals instead of individual mirrors. By way of comparison, LCD projectors use...
) manufacturers including Micron Technologies and Omnivision. Most micro projectors employ one of these imagers combined with color-sequential (RGB
RGB color model
The RGB color model is an additive color model in which red, green, and blue light is added together in various ways to reproduce a broad array of colors...
) LEDs in either a single or triple architecture format. Manufacturers that have adopted this technology include Optoma's PK201 / PK301 (DLP), 3M's MPro 160 / 180 (LCoS), Aiptek's V50 (DLP), AAXA's M2 (LCoS), Bonitor MP302 (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 + 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 + laser technology and AAXA's laser + 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. Laser scanning projectors
Laser video projector
A laser video projector is a video projector that modulates a laser beam in order to project a raster-based image. The systems work either by scanning the entire picture a dot at a time and modulating the laser directly at high frequency, much like the electron beams in a CRT, or by optically...
such as Microvision's ShowX and AAXA's L1 offer very good color gamut
Gamut
In color reproduction, including computer graphics and photography, the gamut, or color gamut , is a certain complete subset of colors. The most common usage refers to the subset of colors which can be accurately represented in a given circumstance, such as within a given color space or by a...
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
Speckle pattern
A speckle pattern is a random intensity pattern produced by the mutual interference of a set of wavefronts. This phenomenon has been investigated by scientists since the time of Newton, but speckles have come into prominence since the invention of the laser and have now found a variety of...
along with thermal instability primarily due to the pumped green laser in the image remains a major challenge.
Applications
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.Mobile
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.Example of phone with a built in DLP projector: I8520 (Galaxy Beam)
I8520 (Galaxy Beam)
The Samsung i8520 is a smartphone produced by Samsung. Its main feature is a built-in DLP WVGA projector that is able to project images at up to in size at 6 to 9 lumens...
, the LG eXpo Projector Phone, and the NTT DoCoMo F-04B Projector Phone.
Gaming
Handheld projectors, in particular projector phones, could offer new possibilities for mobile gaming as demonstrated by the adaptation of the PlayStation 3PlayStation 3
The is the third home video game console produced by Sony Computer Entertainment and the successor to the PlayStation 2 as part of the PlayStation series. The PlayStation 3 competes with Microsoft's Xbox 360 and Nintendo's Wii as part of the seventh generation of video game consoles...
game LittleBigPlanet
LittleBigPlanet
LittleBigPlanet, commonly abbreviated LBP, is a puzzle platformer video game, based on user-generated content, for the PlayStation 3 first announced on 7 March 2007, by Phil Harrison at the Game Developers Conference in San Francisco, California...
. 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 trackingFinger tracking
In the field of technology and image processing, finger tracking is a high-resolution technique that is employed to know the consecutive position of the fingers of the user and hence represent objects in 3D....
. The MIT Media Lab is developing a wearable gestural interface device named SixthSense. Lisa Cowan from UCSD showed a proof of concept of gesture recognition using shadow-occluding of the projector. 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 webcamWebcam
A webcam is a video camera that feeds its images in real time to a computer or computer network, often via USB, ethernet, or Wi-Fi.Their most popular use is the establishment of video links, permitting computers to act as videophones or videoconference stations. This common use as a video camera...
, a laser pointer
Laser pointer
A laser pointer or laser pen is a small portable device with a power source and a laser emitting a very narrow coherent low-powered beam of visible light, intended to be used to highlight something of interest by illuminating it with a small bright spot of colored light...
, 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.