Plasma tv when was it invented

In addition, the higher definition and refresh rate resulted in a much higher-quality picture. To understand the lure of plasma and how it managed to conquer hearts and living rooms alike, you must look beyond the pretty screen and deep into the heart of the technology behind it.

Think of a plasma TV as a neon lamp. There are horizontal and vertical electrode grids and a phosphor array. But the genesis of the technology had nothing to do with the entertainment industry. In this case, it was the need for a high-quality display for computer-based education. Donald L Bitzer, Prof. The technology evolved fast — literally from lab glassware to the best TV screens — in a very short space of time.

However, as would be the case with any technology product for the consumer market, there was a long period of low-volume but high-cost production. The first manufacturer to take the dive into making plasma in serious numbers was Fujitsu, making a inch screen in It was the first time that a large TV was available in a form that could be mounted on a wall.

This was a huge leap forward from the furniture-piece CRT TV sets that were boxy and heavy, although sturdy. Remember, also, that it was a strange world where small screens and large screens LCD and projection respectively were flat, but the ones in the middle inch to inch were curved. Unseen NEMS tags could become a powerful weapon in the global battle against counterfeit products, even counterfeit bills.

Here's a description of the physical principles on which these devices are based and a brief overview of what would be involved in their production and operation. The slices of bread are two nanometer-thick conductive layers of indium tin oxide, a material commonly used to make transparent electrodes, such as those for the touch screen on your phone.

The filling is a nm-thick piezoelectric film composed of a scandium-doped aluminum nitride, which is similarly transparent. With lithographic techniques similar to those used to fabricate integrated circuits, we etch a pattern in the sandwich that includes a ring in the middle suspended by four slender arms.

That design leaves the circular surface free to vibrate. The material making up the piezoelectric film is, of course, subject to the piezoelectric effect : When mechanically deformed, the material generates an electric voltage across it.

More important here is that such materials also experience what is known as the converse piezoelectric effect—an applied voltage induces mechanical deformation.

We take advantage of that phenomenon to induce oscillations in the flexible part of the tag. To accomplish this, we use lithography to fabricate a coil on the perimeter of the tag. This coil is connected at one end to the top conductive layer and on the other end to the bottom conductive layer. Subjecting the tag to an oscillating magnetic field creates an oscillating voltage across the piezoelectric layer, as dictated by Faraday's law of electromagnetic induction.

The resulting mechanical deformation of the piezo film in turn causes the flexible parts of the tag to vibrate. This vibration will become most intense when the frequency of excitation matches the natural frequency of the tiny mechanical oscillator. This is simple resonance, the phenomenon that allows an opera singer's voice to shatter a wine glass when the right note is hit and if the singer tries really, really hard.

It's also what famously triggered the collapse of the Broughton suspension bridge near Manchester, England, in , when 74 members of the 60th Rifle Corps marched across it with their footsteps landing in time with the natural mechanical resonance of the bridge.

After that incident, British soldiers were instructed to break step when they marched across bridges! In our case, the relevant excitation is the oscillation of the magnetic field applied by a scanner, which induces the highest amplitude vibration when it matches the frequency of mechanical resonance of the flexible part of the tag.

These electron micrographs show some of the tags the authors have fabricated, which can take various forms. The preferred geometry top is a circular tag containing a piezoelectric ring suspended by four beams. It includes a coil lighter shade , which connects with electrode layers on the top and bottom of the ring. Voltages induced in this coil by an external scanner set up mechanical oscillations in the ring. In truth, the situation is more complicated than this.

The flexible portion of the tag doesn't have just one resonant frequency—it has many. It's like the membrane on a drum, which can oscillate in various ways. The left side might go up as the right side goes down, and vice versa. Or the middle might be rising as the perimeter shifts downward. Indeed, there are all sorts of ways that the membrane of a drum deforms when it is struck. And each of those oscillation patterns has its own resonant frequency. We designed our nanometer-scale tags to vibrate like tiny drumheads, with many possible modes of oscillation.

The tags are so tiny—just a few micrometers across—that their vibrations take place at radio frequencies in the range of 80 to 90 megahertz. At this scale, more than the geometry of the tag matters: the vagaries of manufacturing also come into play. For example, the thickness of the sandwich, which is nominally around nm, will vary slightly from place to place. The diameter or the circularity of the ring-shaped portion is also not going to be identical from sample to sample.

These subtle manufacturing variations will affect the mechanical properties of the device, including its resonant frequencies. In addition, at this scale the materials used to make the device are not perfectly homogeneous. In particular, in the piezoelectric layer there are intrinsic variations in the crystal structure. Because of the ample amount of scandium doping, conical clusters of cubic crystals form randomly within the matrix of hexagonal crystals that make up the aluminum nitride grains.

The random positioning of those tiny cones creates significant differences in the resonances that arise in seemingly identical tags. Random variations like these can give rise to troublesome defects in the manufacture of some microelectronic devices. Here, though, random variation is not a bug—it's a feature! It allows each tag that is fabricated to serve as a unique marker.

That is, while the resonances exhibited by a tag are controlled in a general way by its geometry, the exact frequencies, amplitudes, and sharpness of each of its resonances are the result of random variations. That makes each of these items unique and prevents a tag from being cloned, counterfeited, or otherwise manufactured in a way that would reproduce all the properties of the resonances seen in the original.

For discretely labeling something like a batch of medicine to document its provenance and prove its authenticity, it's just what the doctor ordered.

You might be wondering at this point how we can detect and characterize the unique characteristics of the oscillations taking place within these tiny tags. One way, in principle, would be to put the device under a vibrometer microscope and look at it move. While that's possible—and we've done it in the course of our laboratory studies—this strategy wouldn't be practical or effective in commercial applications. But it turns out that measuring the resonances of these tags isn't at all difficult.

That's because the electronic scanner that excites vibrations in the tag has to supply the energy that maintains those vibrations. And it's straightforward for the electronic scanner to determine the frequencies at which energy is being sapped in this way. The authors directly measured the surface topography of a tag using a digital holographic microscope, which is able to scan reflective surfaces and precisely measure their heights top.

The authors also modeled various modes of oscillation of the flexible parts of such a tag bottom. Each mode has a characteristic resonant frequency, which varies with both the geometry of the tag and its physical composition. University of Florida; Bottom: James Provost. The scanner we are using at the moment is just a standard piece of electronic test equipment called a network analyzer. The word network here refers to the network of electrical components—resistors, and capacitors, and inductors—in the circuit being tested, not to a computer network like the Internet.

The sensor we attach to the network analyzer is just a tiny coil, which is positioned within a couple of millimeters of the tag. With this gear, we can readily measure the unique resonances of an individual tag. We record that signature by measuring how much the various resonant-frequency peaks are offset from those of an ideal tag of the relevant geometry.

Sure it was okay for watching tv shows, but the resolution for computers was terrible. By the end of the year the first plasma monitor was in operation. Today's plasma TVs have millions of cells that comprise the color and resolution of the screen. That initial plasma monitor was only one cell. However, it was still a step in the right direction. There was a set back, though. Liquid crystal displays became the more acceptable method and this technology was put on hold. Fast forward a few years and flat screen television sets became widely popular.

Plasma TV has made a huge impact on how people watch television and use their computers. HDTV has become a very popular item, as evident by the sheer number of plasma television screens in retail stores. The price, once a huge problem due to how expensive they were, is now becoming much more affordable. There are a large number of people who now own these remarkable flat screen televisions. The world owes the scientists at the University of Illinois a great big thank-you.