hitesh report final

Pico Projector

Chapter 1 Introduction

It’s amazing what we carry in our pockets these days. From cell phones to iPods to

PDAs, we have at our fingertips connectivity with friends and colleagues around the world,

libraries of text, music, photos, videos and more. Unfortunately, the displays that we use to

view all this information are also small they are flat-panel screens with just a few square

inches of display area.

No wonder that projectors that display large images from within hand-held electronic

devices-Pico projectors—are drawing so much attention in the tech world. With Pico

projectors, you can project a full-size image onto whatever is near at hand, whether it be the

wall, your shirt, or a piece of paper. Pico projectors represent a core enabling technology for

the future growth of portable devices.

Pico projectors are the latest technology to prove that big things often do come in

small packages. These tiny projectors are embedded in mobile devices to provide large-

screen displays that can be viewed from anywhere .

Pico projectors have an infinite focus that can be projected onto surfaces with any 3D

depth profile and remain in focus. The possible applications are various and many.

Aside from having a larger format for typical mobile applications, such as reading e-

mail and sharing pictures, Pico projectors could be used for impromptu business

presentations or perhaps scientific visualizations.

In 2004, Microvision presented "Scanned Beam Medical Imager" as an introduction

to our MEMS-based, full color scanned beam imaging system. This presentation will provide

an update of the technological advancements since this initial work from 2004.

SCOE, Sudumbare 1 Computer Dept.

Pico Projector

Figure 1.1 Scanned laser: A simple projector design

1.1 Features of Pico projector

All of the Pico Projectors that are currently on the market are essentially first

generation products and are expected to improve greatly over the next several years as the

technology is further developed. It's kind of like the IPods, everybody knows how much

better and cheaper the new IPods are today as compared with the first generation ones. Some

things people can expect to see as the technology improves include higher picture quality,

long battery life, smaller size, full mobile phone and digital camera integration, added

features such as contrast and focus, better brightness for use in normally it rooms, lower

prices, and much more.

The growth of the Pico Projector industry is projected to be huge over the next several

years with total shipments in 2013 expected to be 6 times what they were in 2009. In 2009


Pico Projector

there were about 500,000 shipments of Pico Projectors and this number is expected to be 3

million by 2013 with it being a $1 billion industry. As Pico Projectors get better and begin

being integrated in cell phones their popularity is expected to skyrocket. At some point we

imagine that most everybody will be equipped with a Pico Projector in their pocket.

1.2 Application of Pico projector

1.2.1 Picture browsing

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.

1.2.2 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.

Chapter 2 Types of Pico projector


Pico Projector

2.1 Laser illuminated

Figure 2.1 Pico Projector components

2.1.1 MEMS Drive ASIC

The MEMS Drive ASIC drives the MEMS scanner under closed loop control. The

horizontal scan motion is created by running the horizontal axis at its resonant frequency—

which is typically about 18 KHz for the WVGA (Wide Video Graphics Array) scanner. The

horizontal scan velocity varies sinusoidally with position. The MEMS controller uses

feedback from sensors on the MEMS scanner to keep the system on resonance and at fixed

scan amplitude.

The image is drawn in both directions as the scanner sweeps the beam back and forth.

This helps the system efficiency in two ways. First, by running on resonance, the power

required to drive the scan mirror is minimized.

Second, bi-directional video maximizes the laser use efficiency by minimizing the

video blanking interval. This result in a brighter projector for any given laser output power.


Pico Projector

The vertical scan direction is driven with a standard sawtooth waveform to provide

constant velocity from the top to the bottom of the image and a rapid retrace back to the top

to begin a new frame. This is also managed in closed-loop fashion by the MEMS controller

based on position feedback from the MEMS scanner to maintain a smooth and linear

trajectory. The frame rate is typically 60Hz for an 848 x 480 WVGA resolution. It can be

increased when the projector is used in lower resolution applications.

2.1.2 Video ASIC

The video processor accepts either RGB or YUV (NTSC/PAL) input. A video buffer

is provided to allow artifact-free scan conversion of input video. Gamma correction and

colorspace conversion are applied to enable accurate mapping of input colors to the wide

laser color gamut. A scaling engine is available for upconverting lower resolution video

content.

A proprietary Virtual Pixel Synthesis (VPS) engine uses a high-resolution

interpolation to map the input pixels to the sinusoidal horizontal trajectory. The VPS engine

demonstrates how projector functions have been shifted from the optics to the electronics in

the scanned laser paradigm. It effectively maps the input pixels onto a high-resolution virtual

coordinate grid. Besides enabling the repositioning of video information with subpixel

accuracy onto the sinusoidal scan, the VPS engine optimizes the image quality. Brightness

uniformity is managed in the VPS engine by adjusting coefficients that control the overall

brightness map for the display.

2.1.3 Biaxial MEMS scanner

The MEMS scanning mirror consists of a reflector suspended in a gimbal frame

containing a micro fabricated electrical coil. Permanent magnets are assembled around the


Pico Projector

MEMS die to supply a magnetic field. Applying electrical current to the MEMS coil

generates a magnetic torque on the gimbal frame with components along both of the desired

axes of rotation, as illustrated in Figure 2.2. One component of the torque is oriented to cause

rotation of the gimbal frame about its flexure suspension, This torque component is used to

convert the frequency content of the mirror drive signal below any resonant frequencies of

the MEMS to a sawtooth ramp mirror rotation corresponding to the vertical display axis.

A second torque component causes rotation of the gimbal frame about an axis normal

to its flexure suspension,. This component is used to operate the scanning mirror on a

resonant mode of vibration consisting mainly of rotation of the reflector about its flexure

suspension to the gimbal frame, and corresponding to the horizontal display axis.

Figure 2.2 MEMS scanning mirror

2.1.4 Lasers

Technology for the red and blue lasers in the Pico projector leverages the technology

of similar lasers that are used for the optical disk storage industry. The wavelength

requirements are shifted somewhat, but the basic technology is the same—GaAlInP red laser

diodes and GaN blue laser diodes.

Pico projectors incorporate green lasers as well. Prior to the push for laser projectors,

green lasers had not been used for any similar high-volume applications. The technology for

the green laser in the Pico projector is based on infra-red lasers developed for the telecom


Pico Projector

industry, the other massive market for laser technology. Robust near-infra-red laser diodes

with very high modulation bandwidths are combined with a frequency-doubling crystal,

usually periodically-poled lithium niobate, to produce a green laser that can be directly

modulated. With an eye toward the burgeoning Pico projector industry, several companies,

including Corning and OSRAM, are ramping up production of suitable green lasers.

Figure 2.3 Scan engine sub system with MEMS scanning mirror and laser light sources.

2.2 LED illuminated

2.2.1 FLCOS Micro display

Displaytech’s FLCOS panels provide the fast switching needed for single-panel

sequential color, without the usual electronic system complexity associated with re-ordering

standard video data. For early engineering samples of Displaytech’s LV-SVGA panel.

Throughput is essentially independent of numerical aperture (NA); FLCOS cell gap choice

maximizes throughput in the green with throughput in the blue and red slightly lower. Here,

color throughputs are representative of all white throughputs, unlike in color-filter-array

(CFA) panels where fringing-field effects dim saturated-color content relative to all white..

Circles represent contrast obtained for each LED primary color with the beam splitter in

collimated light, while the diamonds shows photopically weighted white-light contrast with

the beam splitter in converging light. Comparing these two indicates the degree to which the


Pico Projector

in-plane quarter-wave retardance of the FLCOS OFF state compensates for skew-ray

depolarization on the PBS.

2.2.2 Polarizing Beam Splitters

The ideal polarizing beam splitter (PBS) for a single-panel Pico projector would

provide high round-trip optical throughput for all colors, and over a large range of angles, to

enable small microdisplay panels to work with relatively large light sources. Three

technologies could provide these characteristics:

(1) Dielectric coatings (MacNeille),

(2) wire-grid arrays

(3) Birefringent film stacks such as 3M’s “multi-layer optical film” (MOF)

2.2.3 LED’s White Balance, and Duty Cycle

Here three types of LED’s are used that are red, green, and blue. Relative durations of

red, green, and blue fields are adjusted to give a desired white balance at the allowed pulse

drive currents. The FLCOS panel employs pulse width modulation all pixels are written ON

at the beginning of each field, with the illumination held off for a blanking time slightly

longer than the FLC response time to allow black pixels to attain their OFF state. For DC

balance current FLCOS panels require 50% of the duty cycle be devoted to an inverse image

with illumination blanked, resulting in the net LED on-times , leading directly to the LED

light outputs .The total LED light output serves as the input to the projector illumination stays

on until even full-bright pixels have switched OFF. LED colors can be mixed during a given

color field to produce higher light output.

Chapter 3 Working of Pico projector

3.1 Laser illuminated


Pico Projector

The architecture is quite simple, consisting of one red, one green, and one blue laser,

each with a lens near the laser output that collects the light from the laser and provides a very

low NA (numerical aperture) beam at the output. The light from the three lasers is then

combined with dichroic elements into a single white beam. Using a beam splitter or basic

fold-mirror optics, the beam is relayed onto a biaxial MEMS scanning mirror that scans the

beam in a raster pattern. The projected image is created by modulating the three lasers

synchronously with the position of the scanned beam. The complete projector engine, also

known as the Integrated Photonics Module, or IPM, is just 7 mm in height and 5 cc in total

volume.

There are a number of advantages related to the simple design. The essence of the

design is that, with the exception of the scanner, the rest of the optics engine deals with

making a single pixel. All three lasers are driven simultaneously at the levels needed to create

the proper color mix for each pixel. This produces brilliant images with the wide color gamut

available from RGB lasers. The colors are not created sequentially and thus there is no color

breakup. (In color sequential projectors, color breakup can be seen when the viewer moves

his head rapidly or when the projector itself moves, as might be the case with handheld

projectors.)

Direct-driving of the lasers pixel-by-pixel at just the levels required brings the

advantages of better power efficiency and inherently high contrast. The efficiency is

improved, since the lasers are only on at the level needed for each pixel. The contrast is high

because the lasers are completely off for black pixels rather than using an SLM (spatial light

modulator) to deflect or absorb any excess intensity. The single-pixel collection optics are

optimized to take the particular beam properties of the red, green, or blue laser and relay it

through the scanner and onto the screen with high efficiency and image quality. The pixel

profile is designed to provide high resolution and infinite focus with a smooth non-pixelated

image.

The single pixel design also gives high optical efficiency compared to other projector

technologies. With the simple optomechanical design, the electronics design becomes more

challenging as some of the display complexity is moved to the electronics. This approach

requires the ability to accurately place pixels and to modulate the laser at pixel rates.

Infinite focus:


Pico Projector

In Microvision’s Pico projector display engine, there is no projection lens. The

projected beam directly leaves the MEMS scanner and creates an image on whatever surface

it is shown upon. Because of the scanned single pixel design, light-collection efficiency is

kept high by placing the collection lenses near the output of the lasers, while the output beam

NA is very low. By design, the rate of expansion of the single-pixel beam is matched to the

rate that the scanned image size grows. As a result, the projected image is always in focus.

When one of the three lasers is not needed due to the image content it is left off so that its

power consumption is minimized.

The choice of which wavelength to use for the lasers is based on two considerations.

First is the response of the human eye (the photopic response) to different wavelengths. This

response is a somewhat Gaussian-looking curve that peaks in the green-wavelength region

and falls off significantly in red and blue. The amount of red and blue power needed to get a

white-balanced display varies rapidly with wavelength.

The scanned laser projector paradigm provides a path forward to higher-resolution projectors

without growth in size. Unlike fixed pixel-based projector technologies—in which increased

resolution means growth in the number of pixels in the array—the single-pixel, single-scan-

mirror nature of the Pico projector engine remains the same, even as the resolution of the

projected display increases.

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.


Pico Projector

Figure 3.1 Scanned laser: A simple projector design


Pico Projector

3.2 LED illuminated

Figure 3.2 Example Pico-projection optical systems: (a) System I

Figure 3.2 shows two example Pico-projection optical system configurations. System I in

Figure 3.2(a) has the simplest optical architecture, favoring the highest degree of

miniaturization needed for embedded application. Light from four LED die (RGGB),

packaged on a single substrate, is collected and collimated by a single optic. A holographic

diffuser or lenticular element and lenses convert the inhomogeneous round beam to a uniform

rectangular spot on the microdisplay. System II in Figure 3.3 uses separate red, green, and

blue LEDs superimposed with dichroic filters to minimize effective source area, favoring the

use of a polarization conversion system (PCS) to give the highest light output.


Pico Projector

Figure 3.3 Example Pico-projection optical systems: (b) System II.

The optical configurations of Figure 3.2 are meant to illustrate key concepts rather

than realistic designs. With regard to the illumination optics in particular there are a wide

variety of design options, only a few of which are illustrated. For example, light emitted from

the LED could be collected by an all-refractive optic as in Figure 3.2 a combination refractive

and reflective optic (b) or by a CPC (compound parabolic concentrator), perhaps with

rectangular cross section (not shown). Uniform, efficient illumination of the display panel can

be obtained by using tailored diffusers (a), fly’s-eye lenslet arrays (b), or by imaging either

the output of a rectangular rod integrator or a rectangular LED directly onto the panel (not

shown). Polarization efficiency can be boosted by reflecting the unused polarization back

through some scrambling or rotating element onto the LED die which again reflects some

portion of the light back towards the panel (polarization recycling). Alternately, unpolarized

light emitted by the LED can be split into its two components by a polarizing beam splitter

(PBS).The polarization of one component is then rotated by a wave plate prior to its

recombination with the other to form a single beam (polarization conversion).


Pico Projector

In spite of the diversity of system design choices there are fundamental limitations on

achievable system light output independent of the design. The optical Brightness Theorem

dictates a size scale for light sources used in projection displays. The maximum useful light-

source area AS shares a relationship with the display panel area AP and the acceptance angle

θP of the optical system, according to equation (1): ASsin2 θS < APsin2 θP. (1)

The example of a hypothetical lambertian LED light source with Displaytech’s 0.46-

inch diagonal SVGA FLCOS panel helps clarify these limitations. The lambertian source

emits uniformly into a hemisphere ( θS = 90°). The 0.46-inch display panel (AP = 73 mm2

with 5% overfill in horizontal and vertical directions) projects an image through an f /2

projection lens (sin θP = 0.25).Therefore, the maximum useful LED area AS is 4.6 mm2,

equivalent to an LED emission area of about 2.1 × 2.1 mm. Using more or larger LEDs

cannot raise the image brightness for a display panel of this size and an optical system of this

speed. We now describe the characteristics of the key engine components prior to estimating

projection system light budgets.


Pico Projector

Chapter 4 Pico projector technology

A number of companies around the world are actively pursuing Pico-projector technology.

One way to view the big picture is to categorize the projector technologies based on the

approaches being used to generate the projected images, including those that result from (1)

scanning a pixel in two dimensions, (2) imaging a 2D array of pixels, and (3) mixing imaging

and scanning.

4.1 Imaging Pico projectors

These projectors follow the basic design used in small-business projectors. A small

spatial light modulator (SLM), which has an individually addressable modulator for each

pixel, is used to create the picture. The SLM is imaged by a projection lens onto the

projection surface. Unlike business projectors, which sometimes use three SLM panels (one

for each color), these projectors use just a single SLM to meet the Pico form factor.

Illumination in these systems comes from either lasers or LEDs. The light is collected and

optically conditioned into a uniform beam that illuminates all the pixels in the SLM at once.

The pixel modulators absorb or deflect light from the illumination beam to create the

modulated pixel gray levels. These projectors require focusing and have a potential power

disadvantage, since the SLM illumination beam must always be on.

4.2 Color sequential

Color sequential is the most common approach to produce full color and requires a

fast modulator technology capable of cycling through all colors during a single video frame

interval. SLM technologies that support color sequential include the DLP (Digital Light

Processing from Texas Instruments) and FLCOS (Ferro-electric liquid crystal on silicon;

made by Display-tech and others). Color sequential has the advantage of good color gamut

and one-third the pixel count of color filter system with the same display resolution. Color

breakup is an artifact associated with the color sequential approach that may be disturbing to

some.


Pico Projector

4.3 Color filter array

The color filter approach uses an array of color filters built into the SLM. It is used

with liquid-crystal-on-silicon modulators based on the more commonly used nematic liquid

crystals. It sacrifices some of the color gamut available with RGB light sources (assuming

white LED illumination), and requires a pixel count that is 3X the display resolution;

however, it avoids color breakup. HiMax is one company that offers a color-filter-based

LCOS panel.

4.4 Scanning Pico projectors

Scanning Pico-projectors directly utilize the narrow divergence of laser beams, and

some form of 2D scanning to “paint” an image, pixel by pixel. Usually the scan pattern is

similar to the raster pattern used in traditional television, albeit in this case it is photons,

rather than electrons, being scanned. Some designs use separate scanners for the horizontal

and vertical scanning directions, while others use a single biaxial scanner. The specific beam

trajectory also varies depending on the type of scanner used. Since the scanner replaces an

array of pixels and projection optics, these projectors can be very small while remaining in

focus at any projection distance. Microvision’s Pico Projector falls into this category.

4.5 Mixed imaging and scanning Pico projectors

Mixed imaging and scanning Pico projectors use a one-dimensional spatial light

modulator to create a single column of pixels and a 1D scanner to sweep the column

horizontally, thereby creating a 2D image. Like the imaging-type projectors, a projection lens

is used to image the SLM onto the projection surface. The 1D SLM is based on the

diffraction of laser light. Each pixel consists of a set of reflective ribbons located side-by-side

that can be individually shifted in a direction perpendicular to their flat surface to create

either a plane mirror or a diffraction grating. Modulation occurs by illuminating the SLM

with a uniform beam and adjusting the diffraction grating for each pixel to diffract the desired

amount of light.


Pico Projector

A gray level is achieved by allowing only the diffracted (or the remaining

undiffracted) light to pass through the projector and blocking the rest. One-dimensional

SLMs of this type include Sony’s GLV (grating light valve), Samsung’s SOM (spatial optical

modulator), and Kodak’s GEMS (grating electro mechanical system). To the best of our

knowledge, of these three, only Samsung is actively pursuing this approach for a Pico-

projector.


Pico Projector

Chapter 5 Interfacing with devices

5.1 Requirement in order to operate in mobile

5.1.1 Size: The height or thickness of the projector is its most important characteristic; the

technology must be able to be embedded in thin handheld devices. Both height and volume

should be minimized. The initial products will have projector engine sizes ranging in height

from 7 to 14 mm and in overall volume from 5 to 10 cc.

5.1.2 Brightness: The brighter the better. Brightness is limited by the available brightness of

the light sources, either lasers or LEDs, the optical efficiency of the projector design, and by

the need for low-power operation in order to maximize battery life. Initial product offerings

will be in the range of 5-10 lumens.

5.1.3 Image size: In general, the shorter the distance it takes for the projector to produce a

large image, the better—at least up to a point. A one-to-one distance/image-size ratio

(projection angle of 53 degrees) is probably a good target. The first round of products on the

market will have projection angles in the range of 30-45 degrees.

5.1.4 Focus-free operation: Focus-free operation is a very desirable attribute in mobile

applications. It is like “point and shoot” in a camera. Unlike typical projectors used in

business settings, Pico-projectors are designed for mobile Use (in other words, the distance

from the projector to the image will likely change often).

5.1.5 Resolution: Resolution can be expected to continue to grow as product technology

matures. The wide screen for-mat is generally desirable for viewing video content. Initial

product offerings will typically offer resolutions from QVGA (320 x 240) to WVGA (848 x

480).


Pico Projector

5.1.6 Color: Pico-projectors typically use either lasers or red, green and blue LEDs for light

sources. In both cases, the result is large color gamuts that far exceed the usual color range

experience of TVs, monitors, and conference-room-type projectors. White LEDs used with

color filters yield a reduced color gamut.

5.1.7 Contrast: The higher the better. Just as brightness is a measure of the absolute

whiteness of Pico- projectors, contrast is the measure of their absolute darkness. Contrast is

the dynamic range of a display, making the difference between washed out images and crisp

dramatic-looking images.

5.1.8 Battery life: A starting goal for mobile devices is that they should last for the length of

a complete movie. This puts the lower limit at around 1.5 hours.

5.2 Connection with PC’s

The Pico 2.0 connects directly to a PC and displays the image output from the PC.

The resolution of the PC needs to be 640 x 480. If the PC’s video output port is DVI out, a

DVI-to-HDMI adapter can be used to connect to the HDMI input of the Pico 2.0 as seen in

figure.

Figure5.2 Pico 2.0 Development Kit Setup with a PC


Pico Projector

The Pico 2.0 is compatible with the Beagle Board. The Pico-Beagle configuration is

shown in figure 5.3

The Pico 2.0 Development kit includes the Pico 2.0 module, a power supply, and an

HDMI cable. A USB to Mini-USB cable can be used to power the Beagle Board. An SD card

containing the content that will be displayed is also necessary.

The Pico 2.0 kit can display the output from the Beagle Board. The Beagle Board

needs to be configured in VGA display mode in order to interface to the Pico 2.0 kit.

Figure 5.3 Pico 2.0 Development Kit Setup with a Beagle Board

Full System Configuration Considerations

Perform steps 1 through 7 the first time the Beagle Board is used with a preconfigured SD

card. After performing these steps the content on the SD card will start playing at boot up

with this Beagle Board without being connected to a PC.


Pico Projector

Step 1 – Connect the power supply to the Pico 2.0.

Step 2 – Connect a serial cable to the PC and the RS232 connector on the Beagle Board.

Step 3 – Turn on the Pico 2.0 kit. (wait until step five to connect power to the Beagle Board)

Step 4 – Open Tera Term Pro and select the Serial, port: COM1 (for the New Connection)

Step 5 – Go to Setup (top of the window) and select serial port...note the number of selections

on the serial port setup pop-up window. Configure as shown in figure shown below.

Figure 5.4 setup window

Serial Port Setup

Step 7 – At the prompt #, enter the following commands. The Beagle Board will

automatically boot from the SD card the next time it is reset.

Step 8 – The next time the Pico 2.0 kit boots up with the configured SD card the content will

automatically be displayed out of the Pico 2.0. Apply power to the Pico 2.0 then apply power

to the Beagle Board once the Beagle Board icon appears it will take a few seconds before the

content starts playing on the Pico 2.0.


Pico Projector

Chapter 6 Advantages and disadvantages

6.1 Advantages

High flexibility of moving and operating.

Space saving: As the tiny size takes very less area to fit or attach with pc or mobiles.

Convenient development paradigm these projectors are easy to develop.

Easy to handle.

Highly portable.

Pico projector will facilitate personal and shared viewing of high resolution images in

situations where flat-panel displays on mobile devices is too small.

These projectors involve miniaturized hardware and software that can project digital

images onto any nearby viewing surface, such as a wall.

Pico Projectors, with their small size, are significantly cheaper than traditional

projectors.

Pico Projectors are also much better than older projectors because their images can be

displayed on any surface rather than only a smooth, flat, white surface.

Pico projector consumes less power.

The old projector have big size instead of that pico projector are very compact

6.2 Disadvantages

The range of this projector is not more it is about 1.1 to 1.5m.

Pico Projectors have the disadvantage of coming with little or no added features such

as contrast or focus. However these features will probably be added as the Pico

Projector is further developed.

Currently most Pico Projector displays are not bright enough to be used in a normally

lit room. Again this is another feature that will likely be improved with time.

Conclusion


Pico Projector

A Pico-projector display engine using MEMS scanning mirror and laser light sources

has a combination of features and performance characteristics that make it suitable for

integration into portable electronics.

The Pico projection systems envisioned here are optimized for the varying

requirements of embedded, companion, and stand-alone mobile applications.

The scanned laser projector paradigm provides a path forward to higher-resolution

projectors without growth in size. Unlike fixed pixel-based projector technologies—in which

increased resolution means growth in the number of pixels in the array—the single-pixel,

single-scan-mirror nature of the Pico Projector engine remains the same, even as the

resolution of the projected display increases.

Bibliography


Pico Projector

1. R. Sprague et al. “Mobile Projectors Using Scanned beam Displays”, from “Mobile

Displays, Technology and Applications”.

2. W. Davis et. al. “MEMS-Based Pico Projector Display”, Proceedings of IEEE/LEOS

Optical MEMS & Nanophotonics.

3. http://www.microvision.com/barcode.

4. Niesten, M., R. Sprague, J. Miller, “Scanning Laser Beam Displays.

5. M. G. Robinson, J. Chen, and G. D. Sharp, Polarization Engineering for LCD

Projection.

6. M. P. Krijn, B. A. Salters, and O. H. Willemsen, “LED-based mini-projectors”.


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