PicoP Fundamental Advantages
July 9th, 2009
by Ben Averch
PicoP’s focus free operation is awesome. Can pico projectors using LCOS or DLP achieve this?
Infinite focus, along with our rich laser colors, really creates the “wow factor” for SHOWWX and PicoP. This is a unique advantage of scanned (MEMS) laser technology. To achieve infinite focus, one needs to have the single beam properties of the laser which are then scanned across the image. It really does require breaking the tie between projection angle and the light beam used to make each pixel, and only scanned beam can do this.
Depth of focus and image projection angle are tightly coupled in imaging-type projectors, (e.g., LCOS and DLP). The projection lens needs to have a very short focal length in order to have a wide projection angle, and it needs to have a very small aperture (i.e., very large F# where F# = focal length/lens diameter) to increase the depth of focus. Simple calculations show that the infinite focus property needs roughly an F/400 beam. High F/# beams like this are inherent in a scanned laser architecture. Other systems can try to approach this by reducing the projection angle or sacrificing brightness but will still fall far short of achieving infinite focus.
How about the electronics in PicoP?
A strength of our scanned laser design is that we consciously keep the engine simple (single pixel, no projection optics, etc.) and shift complexity from the optomechanics into the electronics where mature ASIC technology is available. It allows us to get much better image quality through intelligent algorithms at virtually no added system cost (size, power, and $$).
LCOS or DLP projectors that are flood illuminated by CW (continuous wave) light sources have very poor optical efficiency since they create images by throwing away light. Furthermore, creating a uniform illumination beam also wastes a fair amount of light. Both scanned laser and imaging-type projectors need a laser capable of producing the brightest pixel, but the scanned laser paradigm only uses the laser at that brightness when it’s needed, while imaging projectors need to run their lasers at maximum brightness continuously.
Many companies are trying to use secondary specs to convince the world that they are more power efficient than other technologies. Fortunately for the general public, there is a simple litmus test to determine which device is better in terms of power management. This test is how long will projector operate on a single battery charge using a standard battery. All existing LCOS and DLP products that we have evaluated discharge after 40-60 min of continuous operation. Our SHOWWX is targeted to operate continously for a significantly longer duration, over 1.5 hours for typical video of NTSC format.
Can you talk about laser speckle? What’s this and what are some of the image quality benefits of PicoP?
Laser speckle is an effect of laser light hitting a surface, where the reflection back to an observer appears as a subtle glistening. Microvision has run extensive testing with customers and end users, and we have found little evidence to suggest that this effect will inhibit broad user adoption. In fact, Microvision’s image quality is considered the highest quality among pico projector solutions.
LED technology houses (LCOS and DLP) are using “speckle” as the negative attribute or “artifact” against laser illumination, while being mum about LED/LCOS/DLP inherent artifacts such as poor brightness uniformity. Brightness uniformity means that the image has the same brightness in the center as it does at the edges. We believe the user experience of LED/LCOS and LED/DLP is compromised since 8-10 lumens of brightness can be measured only at the center of the image, while in the corners you see only 3 lumens! We call this the “flashlight effect”.
To enhance brightness uniformity in PicoP, the laser is modulated as a function of mirror position. This is completely implemented with the video ASIC where the incremental cost is virtually zero. The result is a huge benefit in performance. Other benefits of this approach include high-quality keystone correction, the ability to perform chromatic corrections, and other functions that are not possible with flat-panel-based displays.
In terms of resolution, Microvision’s PicoP is the highest resolution pico projector currently available. Likewise, for future generations, Microvision can scale PicoP to HD resolution without impacting the physical footprint or thickness. No fixed pixel array can do this, since there is a physical element for each pixel. Hence, LCOS/DLP panels will need to scale in size to increase resolution, or shrink their physical pixels, leading to potential manufacturing challenges.
SHOWWX/PicoP can clearly display 10 point font, and has greater small point font readability than DLP/LCOS pico projectors that we have evaluated. In fact, the competitive products based on LCOS or DLP technology are struggling to display text that is 18 point font or lower.
Lastly, the colors of our solution are agreed by customers and end users to be the richest, most saturated colors of any display they have seen.
What about brightness relative to panel based solutions?
Brightness and power (operating life) are in direct conflict with each other. If you dial up brightness, your battery life is greatly reduced, making the final projector not a mobility device. Microvision balances these important constraints better than anyone else. For example, today, Microvision is producing the SHOWWX pico projector with 10 lumen brightness (uniform throughout the image) while delivering it with 1.5 – 2 hrs operating life, and the highest possible resolution (WVGA). The competitive LCOS and DLP products fall short in each of these categories. They typically deliver 5-10 lm center brightness (with 70% reduction in the corners) while providing operating life of 40-60 min, while offering only HVGA to VGA resolution.
Let’s talk about the cost of Microvision’s PicoP relative to LCOS or DLP projectors.
Microvision’s technology uses a relatively inexpensive and highly robust MEMS device, coupled together with affordable red and blue laser diodes. The blue laser, for example, is very similar to the type of laser diode used inside the Blu Ray HD video players. Additionally, Microvision’s PicoP utilizes the newly developed green lasers developed by two leading companies: Corning and Osram. These companies will manufacture production green lasers specifically optimized for scanned beam architecture. There is a growing market demand for RGB lasers due to their superiority as a light source for pico projection applications — and at the same time there are several laser companies competing for this market. As volumes ramp, costs are expected to rapidly decline.
There is no reason to expect panel-based competing technology to be significantly less expensive than Microvision’s when lasers are used.
If you look at the display engine as a whole: MEMS scanner vs LCOS or DLP panel; optics; electronics and light sources (Lasers vs LEDs), it is true that today lasers are more expensive than LEDs. However, MEMS is more economical than either LCOS or DLP, and PicoP technology uses far less optics than the other solutions, making it more cost effective in this area as well. Thus, overall we are similar in cost while providing consumers with features that neither LCOS nor DLP are capable of: focus free operation, highest resolution, best text readibility, the largest screen size at similar distances, richer colors and the best brightness uniformity.
Is Microvision ready for production of SHOWWX?
Microvision has a robust supply chain for PicoP in place and production is due to commence Summer 2009. PicoP and SHOWWX are manufactured by Asia Optical, a global leading consumer electronics ODM and one of the world’s largest manufacturer of cell phone camera modules and digital cameras and camcorders. Asia Optical gives Microvision the ability to scale PicoP production to meet demands for high volume consumer products.
As Robert Lai, Asia Optical Founder, Chairman and CEO said, “Microvision has an outstanding display technology that we believe will revolutionize the mobile handset marketplace. We strongly believe that Microvision’s PicoP display will allow OEMs to enhance the value of their existing and future products as well as provide consumers new and exciting mobile projection display functionality that can not be achieved through traditional display technologies. With our strong global manufacturing and vertical products integration capabilities as well as the extensive experience in working with leading global consumer electronics companies, we are confident that the products we deliver on behalf of Microvision will excite OEMs and the millions of consumers who are looking for high-quality display projection capabilities from their mobile devices.”
How about the supply of green lasers?
Microvision’s supply chain partners for green lasers include Corning and OSRAM. Both of these companies have made significant investments in green laser development to provide this key component for Microvision’s PicoP. Corning and OSRAM are entering initial production in 2009, with volumes to increase in 2010 and beyond.
As Thomas Mills, general manager, Corning Green Lasers said, “We are pleased to be able to work with Microvision, a key player in the projection-display industry, to spearhead the introduction of laser-based microprojectors in 2009,” “This is an important strategic growth opportunity for the advancement of microprojection technology and Corning’s industry-leading green lasers. The G-1000 green laser is a high-quality, compact, and efficient light source optimized for this exciting application.”
This entry was posted on Thursday, July 9th, 2009 at 9:50 am and is filed under Pico Projectors, SHOWWX.
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