Handheld projector

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The Nikon Coolpix S1000pj compact camera projecting an image using its built-in projector. Nikon Coolpix s1000pj projecting.jpg
The Nikon Coolpix S1000pj compact camera projecting an image using its built-in projector.
3M pocket projector 3M pocket projector at B&H Photo jeh.jpg
3M pocket projector
Handheld AAXATech P1 Pico Projector 2009.jpg
Handheld

A handheld projector (also known as a pocket projector, mobile projector, pico projector or mini beamer) is an image projector in a handheld device. It was developed as a computer display device for compact portable devices such as mobile phones, personal digital assistants, and digital cameras, which have sufficient storage capacity to handle presentation materials but are too small to accommodate a display screen that an audience can see easily. Handheld projectors involve miniaturized hardware, and software that can project digital images onto a nearby viewing surface.

Contents

The system comprises five main parts: the battery, the electronics, the laser or LED light sources, the combiner optic, and in some cases, scanning micromirror devices. 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. An important design characteristic of a handheld projector is the ability to project a clear image on various viewing surfaces.

History

Major advances in imaging technology have allowed the introduction of hand-held (pico) type video projectors. 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. [1]

Insight Media market research has divided the leading players in this application into various categories: [2]

Various manufacturers have produced handheld projectors exhibiting high-resolution, good brightness, and low energy consumption in a slightly larger format than pico since 2008. However, most handheld LED projectors, as of December 2017, have been widely criticized for having insufficient brightness for everyday use in a normally lit room.

In 2011, Texas Instruments DLP announced improved chipsets 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.

In 2014 Texas Instruments DLP's imagers occupied a significant portion of the handheld projector market share. In combination with Osram's Ostar series LEDs optical engines based on DLP technology have achieved over 15 lumens per watt for high brightness applications (300–500 lumens with 0.45" imager) and over 20 lumens per watt in low brightness applications (10–50 lumens with 0.2" or 0.3" imagers).

Technologies

Three major image technologies for micro projectors are commonplace:

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, 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 for low 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 employ RGB laser technology, such as Microvision's beam-steering plus laser technology, and AAXA's laser plus LCoS technology.[ citation needed ]

Each method has advantages and disadvantages. 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 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 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, and thermal issues and power consumption greatly reduced.[ citation needed ]

Applications

Handheld projectors can be used for different applications from small conventional projectors. Since 2008 [4] researchers are studying applications that are specifically designed for handheld projectors often using prototypes of mobile phones with an integrated projector.[ citation needed ]

Mobile

21st century mobile phones have the ability to store thousands of photos and can take photos of good quality. Projector phones allow sharing them with a larger audience than on the phone's small screen. [5] One study found that people preferred to view and share photos with projector phones, compared to using conventional mobile phones. [6]

Gaming

Handheld projectors, in particular projector phones, could offer new possibilities for mobile gaming, as demonstrated by the adaptation of the PlayStation 3 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. [7]

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. [8] [9] [10] The MIT Media Lab proposed a wearable gestural interface device named SixthSense. Chris Harrison developed a working system called Omnitouch. [11] Finally, the Light Blue Optics Light Touch is yet another similar device. [12] Lisa Cowan from UCSD showed a proof of concept of gesture recognition using shadow-occluding of the projector, called ShadowPuppets. [13] 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. [14] [15] [16]

Related Research Articles

LCD projector Type of video projector

An LCD projector is a type of video projector for displaying video, images or computer data on a screen or other flat surface. It is a modern equivalent of the slide projector or overhead projector. To display images, LCD projectors typically send light from a metal-halide lamp through a prism or series of dichroic filters that separates light to three polysilicon panels – one each for the red, green and blue components of the video signal. As polarized light passes through the panels, individual pixels can be opened to allow light to pass or closed to block the light. The combination of open and closed pixels can produce a wide range of colors and shades in the projected image.

Gamut Color reproduction

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 certain output device.

Liquid crystal on silicon is a miniaturized reflective active-matrix liquid-crystal display or "microdisplay" using a liquid crystal layer on top of a silicon backplane. It is also referred to as a spatial light modulator. LCoS was initially developed for projection televisions but is now used for wavelength selective switching, structured illumination, near-eye displays and optical pulse shaping. By way of comparison, some LCD projectors use transmissive LCD, allowing light to pass through the liquid crystal.

Video projector Device that projects video onto a surface

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. Video projectors use a very bright Ultra-high-performance lamp, Xenon arc lamp, LED or solid state blue, RB, RGB or remote fiber optic RGB lasers to provide the illumination required to project the image, and most modern ones can correct any curves, blurriness, and other inconsistencies through manual settings. If a blue laser is used, a phosphor wheel is used to turn blue light into white light, which is also the case with white LEDs. A wheel is used in order to prolong the lifespan of the phosphor, as it is degraded by the heat generated by the laser diode. Remote fiber optic RGB laser racks can be placed far away from the projector, and several racks can be housed in a single, central room. Each projector can use up to two racks, and several monochrome lasers are mounted on each rack, the light of which is mixed and transmitted to the projector booth using optical fibers. Projectors using RB lasers use a blue laser with a phosphor wheel in conjunction with a conventional solid state red laser.

Digital Light Processing Set of chipsets

Digital Light Processing (DLP) is a set of chipsets based on optical micro-electro-mechanical technology that uses a digital micromirror device. It was originally developed in 1987 by Larry Hornbeck of Texas Instruments. While the DLP imaging device was invented by Texas Instruments, the first DLP-based projector was introduced by Digital Projection Ltd in 1997. Digital Projection and Texas Instruments were both awarded Emmy Awards in 1998 for the DLP projector technology. DLP is used in a variety of display applications from traditional static displays to interactive displays and also non-traditional embedded applications including medical, security, and industrial uses.

Television set Device for viewing computers screen and shows broadcast through satellites or cables

A television set or television receiver, more commonly called the television, TV, TV set, tube, telly, or tele, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television broadcasts, or using it as a computer monitor. Introduced in the late 1920s in mechanical form, television sets became a popular consumer product after World War II in electronic form, using cathode ray tube (CRT) technology. The addition of color to broadcast television after 1953 further increased the popularity of television sets in the 1960s, and an outdoor antenna became a common feature of suburban homes. The ubiquitous television set became the display device for the first recorded media in the 1970s, such as Betamax, VHS and later DVD. It has been used as a display device since the first generation of home computers and dedicated video game consoles in the 1980s. By the early 2010s, flat-panel television incorporating liquid-crystal display (LCD) technology, especially LED-backlit LCD technology, largely replaced CRT and other display technologies. Modern flat panel TVs are typically capable of high-definition display and can also play content from a USB device. By the late 2010s and early 2020s, most flat panel TVs began to offer 4K and 8K resolutions.

The grating light valve (GLV) is a "micro projection" technology which operates using a dynamically adjustable diffraction grating. It competes with other light valve technologies such as Digital Light Processing (DLP) and liquid crystal on silicon (LCoS) for implementation in video projector devices such as rear-projection televisions. The use of microelectromechanical systems (MEMS) in optical applications, which is known as optical MEMS or micro-opto-electro-mechanical structures (MOEMS), has enabled the possibility to combine the mechanical, electrical and optical components in very small scale.

Blue laser Laser which emits light with blue wavelengths

A blue laser is a laser that emits electromagnetic radiation with a wavelength between 360 and 480 nanometers, which the human eye sees as blue or violet.

Virtual retinal display Display technology

A virtual retinal display (VRD), also known as a retinal scan display (RSD) or retinal projector (RP), is a display technology that draws a raster display directly onto the retina of the eye. The user sees what appears to be a conventional display floating in space in front of them.

CRT projector Older type of video projector that uses small, high intensity CRTs as image generating elements

A CRT projector is a video projector that uses a small, high-brightness cathode ray tube as the image generating element. The image is then focused and enlarged onto a screen using a lens kept in front of the CRT face. The first color CRT projectors came out in the early 1950s. Most modern CRT projectors are color and have three separate CRTs, and their own lenses to achieve color images. The red, green and blue portions of the incoming video signal are processed and sent to the respective CRTs whose images are focused by their lenses to achieve the overall picture on the screen. Various designs have made it to production, including the "direct" CRT-lens design, and the Schmidt CRT, which employed a phosphor screen that illuminates a perforated spherical mirror, all within an evacuated "tube."

Fulldome refers to immersive dome-based video display environments. The dome, horizontal or tilted, is filled with real-time (interactive) or pre-rendered (linear) computer animations, live capture images, or composited environments.

Laser color television, or laser color video display utilizes two or more individually modulated optical (laser) rays of different colors to produce a combined spot that is scanned and projected across the image plane by a polygon-mirror system or less effectively by optoelectronic means to produce a color-television display. 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 cathode ray tube, or by optically spreading and then modulating the laser and scanning a line at a time, the line itself being modulated in much the same way as with digital light processing (DLP).

Large-screen television technology Technology rapidly developed in the late 1990s and 2000s

Large-screen television technology developed rapidly in the late 1990s and 2000s. Prior to the development of thin-screen technologies, rear-projection television was standard for larger displays, and jumbotron, a non-projection video display technology, was used at stadiums and concerts. Various thin-screen technologies are being developed, but only liquid crystal display (LCD), plasma display (PDP) and Digital Light Processing (DLP) have been publicly released. Recent technologies like organic light-emitting diode (OLED) as well as not-yet-released technologies like surface-conduction electron-emitter display (SED) or field emission display (FED) are in development to replace earlier flat-screen technologies in picture quality.

An electronic visual display, informally a screen, is a display device for presentation of images, text, or video transmitted electronically, without producing a permanent record. Electronic visual displays include television sets, computer monitors, and digital signage. By the above definition, an overhead projector could reasonably be considered an electronic visual display since it is a display device for the presentation of an images, plain text, or video transmitted electronically without producing a permanent record. They are also ubiquitous in mobile computing applications like tablet computers, smartphones, and information appliances.

3LCD LCD projection color image generation technology

3LCD is the name and brand of a major LCD projection color image generation technology used in modern digital projectors. 3LCD technology was developed and refined by Japanese imaging company Epson in the 1980s and was first licensed for use in projectors in 1988. In January 1989, Epson launched its first 3LCD projector, the VPJ-700.

MicroTiles

The MicroTiles video display system from Christie Digital is composed of modular 16" × 12" rear projection cube units that can be built together into a large video wall-style display. Each MicroTile unit contains a short-throw projector based on an LED light source and DLP optical imaging. The picture is formed onto the detachable front screen surface.

The Samsung i8520 is a projector-enabled smartphone produced by Samsung. Its main feature is a built-in DLP WVGA projector that is able to project images at up to 50 inches (1,300 mm) in size at 15 lumens. The i8520 also contains an 8-megapixel camera, that can be used along with the projector to allow the user to project directly what is in front of the camera. The camera is also able to record HD video at a resolution of 720p at 30 frame/s. The phone also offers local Wi-Fi connectivity, e-mail, and web browsing, as well as containing a built-in GPS receiver. It was released initially in Singapore on 17 July 2010 with the carrier StarHub.

The Qumi (DPC74A1) is a pocket projector manufactured by Delta Electronics for vendor Vivitek. It was released in May 2011.

A projector phone is a mobile phone that contains a built-in pico projector.

MicroVision, Inc. American laser scanning technology developer

MicroVision, Inc. is an American company that develops laser scanning technology for projection, 3D sensing, and image capture. MicroVision's display technology uses a micro-electrical mechanical systems (MEMS) scanning mirror with red, green, blue, and infrared lasers, optics and electronics to project and/or capture images. The company licenses its products primarily to original equipment manufacturers (OEMs) such as STMicroelectronics.

References

  1. ↑ "Kopin Team up with Explay to Develop Nano-Projector Engine". 2017-03-04.
  2. ↑ Brennesholtz 2008, p.84.
  3. ↑ Freeman, Champion, Madhaven—Scanned Laser Pico-Projectors: Seeing the Big Picture (with a Small Device) http://www.microvision.com/wp-content/uploads/2014/07/OPN_Article.pdf Archived 2017-02-02 at the Wayback Machine
  4. ↑ A. Hang, E. Rukzio, and A. Greaves "Projector Phone: A Study of Using Mobile Phones with Integrated Projector for Interaction with Maps Archived 2011-08-15 at the Wayback Machine " Proceedings of the Conference on Human–Computer Interaction with Mobile Devices and Services (MobileHCI), 2008.
  5. ↑ A. Greaves and E. Rukzio, "View & Share: A Collaborative Media Viewing and Sharing Framework using a Projector Phone", Proceedings of the Workshop on Mobile Interaction with the Real World (MIRW), 2008.
  6. ↑ A. Greaves and E. Rukzio, "View & Share: Exploring Co-Present Viewing and Sharing of Pictures using Personal Projection" Proceedings of the Workshop on Mobile Interaction with the Real World (MIRW), 2009.
  7. ↑ M. Löchtefeld, J. Schöning, M. Rohs, and A. Krüger, "LittleProjectedPlanet: An Augmented Reality Game for Camera Projector Phones Archived 2011-07-19 at the Wayback Machine ", Proceedings of the Workshop on Mobile Interaction with the Real World (MIRW), 2009.
  8. ↑ C. Harrison, H. Benko, and A. Wilson. "OmniTouch: Wearable Multitouch Interaction Everywhere", In Proceedings of the 24th Annual ACM Symposium on User interface Software and Technology (ACM UIST), 2011.
  9. ↑ P. Mistry, P. Maes, and L. Chang, "WUW — wear Ur world: a wearable gestural interface", Extended Abstracts Proceedings of the Conference on Human Factors in Computing Systems (CHI), 2009.
  10. ↑ M. Baldauf and P. Fröhlich, "Supporting Hand Gesture Manipulation of Projected Content with Mobile Phones Archived 2010-06-02 at the Wayback Machine ", Proceedings of the Workshop on Mobile Interaction with the Real World (MIRW), 2009.
  11. ↑ OmniTouch
  12. ↑ Light Blue Optics Light Touch
  13. ↑ Cowan, L., Li, K. "ShadowPuppets: Supporting Collocated Interaction with Mobile Projector Phones Using Hand Shadows", In Proceedings of ACM Conference on Human Factors in Computing Systems (CHI), 2011.
  14. ↑ US Patent #6,275,214, "" Computer presentation system and method with optical tracking of wireless pointer
  15. ↑ US Patent #6,952,198, "" System and method for communication with enhanced optical pointer
  16. ↑ US Patent #7,091,949, " Computer presentation system and method with optical tracking of wireless pointer"

Bibliography

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