12-04-2011, 12:51 PM
PRESENTED BY:
S.VENKATESH
JEET SINHA ROY
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ABSTRACT
Sights and sounds in our world are analog, yet when we electronically acquire, store, and communicate these analog phenomena, there are significant advantages in using digital technology. This was first evident with audio as it was transformed from a technology of analog tape and vinyl records to digital audio CDs.
Video is now making the same conversion to digital technology for acquisition, storage, and communication. Witness the development of digital CCD cameras for image acquisition, digital transmission of TV signals (DBS), and video compression techniques for more efficient transmission, higher density storage on a video CD, or for video conference calls. The natural interface to digital video would be a digital display. But until recently, this possibility seemed as remote as developing a digital loudspeaker to interface with digital audio. Now there is a new MEMS-based projection display technology called Digital Light Processing (DLP) that accepts digital video and transmits to the eye a burst of digital light pulses that the eye interprets as a color analog image.
Digital Light Processing technology provides all digital projection displays that offer superior picture quality in terms of resolution, brightness, contrast, and color fidelity. This paper provides an overview of the digital light processing that have been developed by Texas Instruments for the all-digital display.
INTRODUCTION
1.1 INTRODUCTION TO DLP:
Digital Light Processing is a revolutionary new way to project and display information. Based on the Digital Micro mirror Device developed by Texas Instruments, DLP creates the final page link to display digital visual information. DLP technology is being provided as subsystems or "engines" to market leaders in the consumer, business, and professional segments of the projection display industry. In the same way the compact disc revolutionized the audio industry, DLP will revolutionize video projection.
DLP has three key advantages over existing projection technologies. The inherent digital nature of DLP enables noise-free, precise image quality with digital gray scale and color reproduction. Its digital nature also positions DLP to be the final page link in the digital video infrastructure. DLP is more efficient than competing transmissive liquid crystal display (LCD) technology because it is based on the reflective DMD and does not require polarized light. Finally, close spacing of the micro mirrors causes video images to be projected as seamless pictures with higher perceived resolution. For movie projection, a computer slide presentation, or an interactive, multi-person, worldwide collaboration—DLP is the only choice for digital visual communications, today and in the future.
The world is rapidly moving to an all-digital communications and entertainment infrastructure. DMD and DLP technologies are introduced in the context of that infrastructure.
1.2 INTRODUCTION TO DMD:
Figure 1 The DMD microchip lies at the heart of the DLP system. It consists of an array of digital light Switches that accept electrical words as their inputs and output optical words. Surrounding the DMD are the necessary functionalities to take a digital source and project its undegraded image to a projection screen or hardcopy surface. These functionalities include image processing, memory, Reformatting, timing control, a light source, and projection optics. The input to the DLP system is a digital source (e.g., from a computer or DBS satellite receiver) or it may be NTSC video converted to digital.
The basic building block of DLP technology is the DMD pixel, a reflective digital light switch. It is the equivalent of the electrical switch or gate in memory or microprocessor technologies. Unlike its electrical counterpart, however, the DMD light switch involves not only the electrical domain but also the mechanical and optical domains. Responding to an electrical input signal, the DMD light switch uses electromechanical action to interact with incident light and to switch that light into time-modulated light bundles at its output. This switching scheme is called binary pulse width modulation and is used to produce the sensation of gray scale to the observer's eye.
In the near future, most of the technologies necessary to achieve an all-digital communications and entertainment infrastructure will be available at the right performance and price levels. This will make an all-digital infrastructure chain such as the one shown in Figure 3commercially viable. The All-Digital Infrastructure
The links in this chain include capture, compression, transmission, reception, decompression, hearing, and viewing. But the final page link is missing-an all-digital display. Digital images received today must be translated into analog signals for viewing on today's analog televisions. The digital display block shown in Figure 1 accepts a digital signal, but unlike analog displays of today, it outputs to the eye of the viewer an optical signal that is also digital. The viewer Perceives the digital signal as an analog signal, in essence performing the digital-to-analog (D/A) Conversion physiologically. An all-digital display possesses a degree of image stability and noise immunity that is inherently attributable to its digital nature.[1] Consider a digital word that is input electronically to the display. That word is converted into an optical word that is nearly immune to environmental, aging and manufacturing influences. DLP provides the all-digital projection display solution, accepting a digital electrical input and outputting a digital optical image. Figure 2 shows the functional elements of such a system. The Missing Link in the All-Digital Infrastructure
2. DIGITAL MICRO MIRROR DEVICE
DMD Architecture
The world is rapidly moving to an all-digital communications and entertainment infrastructure.
DMD and DLP technologies are introduced in the context of that infrastructure.
2.1 The Mirror as a Switch
The address circuit and electromechanical superstructure of each pixel support one simple function, the fast and precise rotation of an aluminum micro mirror, 16 μm square, through angles of +10 and p;10 degrees. Figure 4 illustrates the architecture of one pixel, showing the mirror as semitransparent so that the structure underneath can be observed.
INTRODUCTION
Electronics without silicon is unbelievable, but it will come true with the evolution of Diamond or Carbon chip. Now a day we are using silicon for the manufacturing of Electronic Chip’s. It has many disadvantages when it is used in power electronic applications, such as bulk in size, slow operating speed etc. Carbon, Silicon and Germanium are belonging to the same group in the periodic table. They have four valance electrons in their outer shell.
Pure Silicon and Germanium are semiconductors in normal temperature. So in the earlier days they are used widely for the manufacturing of electronic components. But later it is found that Germanium has many disadvantages
Compared to silicon, such as large reverse current, less stability towards temperature etc so in the industry focused in developing electronic components using silicon wafers
Now research people found that Carbon is more advantages than Silicon. By using carbon as the manufacturing material, we can achieve smaller, faster and stronger chips. They are succeeded in making smaller prototypes of Carbon chip. They invented a major component using carbon that is "CARBON NANOTUBE", which is widely used in most modern microprocessors and it will be a major component in the Diamond chip
WHAT IS DIAMOND CHIP?
In single definition, Diamond Chip or carbon Chip is an electronic chip manufactured on a Diamond structural Carbon wafer, or it can be also defined as the electronic component manufactured using carbon as the wafer.
The major component using carbon is (cnt) Carbon Nanotube. Carbon Nanotube is a nano dimensional made by using carbon. It has many unique properties.
HOW IS IT POSSIBLE?
Pure Diamond structural carbon is non-conducting in nature. In order to make it conducting we have to perform doping process. We are using Boron as the p-type doping Agent and the Nitrogen as the n-type doping agent. The doping process is similar to that in the case of Silicon chip manufacturing. But this process will take more time compared with that of silicon because it is very difficult to diffuse through strongly bonded diamond structure. CNT (Carbon Nanotube) is already a semi conductor.
INVENTION:
A diamond semiconductor operates on 81GHz frequency, and is more than twice the speed of earlier devices. This particular chip was first developed by Nippon Telegraph & Telephone Corporation(NTT), Japan.
SOME FACTS:
Unlike silicon & germanium, pure carbon is not a semiconductor in room temperature. Therefore, in order to make it a semiconductor, we use some of the allotropes of carbon.
GRAPHENE is one of the allotropes of carbon which acts as semiconductor. Thus, NANOTUBES, which are derived from GRAPHENE, will also act as semiconductor.
GRAPHENE:
Graphene is an allotrope of carbon, whose structure is one-atom-thick planar sheet of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice.
PROPERTIES OF GRAPHENE:
a. Graphene has remarkably high electron mobility at room temperature.
b. Graphene structure can be doped easily by using chemical dopants and can be converted back to its undoped form just by heating slowly in vacuum.
CARBON NANOTUBES (CNT):
Folding the Graphene sheet into a tube like structure produces CARBON NANOTUBES. It is a nanosize cylinder of carbon atoms.They are made of one or several concentric walls in which carbon atoms are arranged in hexagonal pattern, having a less than one nanometer diameter.
HOW TO MAKE CARBON NANOTUBES?
In a vacuum chamber, the researchers vaporized the metals tantalum and iron, which settled in layers on a silicon wafer. Then they placed the coated wafer at one end of a quartz tube, which was inserted into a furnace. At the wafer’s end of the tube, the furnace temperature was 475 degrees C; but at the opposite end, the temperature varied. The researchers pumped ethylene gas into the tube from the end opposite the wafer. When the temperature at that end approached 800 degrees, the ethylene decomposed, and the iron on the wafer catalyzed the formation of carbon nanotubes.
TYPES OF CARBON NANOTUBES(CNT):
Carbon nanotubes are primarily of two types:
1. Single Walled Nanotubes (SWNT):
Single walled nanotubes are of 3 types as follows:
a. Zigzag
b. Chiral
c. Armchair