What are Lasers Used for

Lasers are used in practically every major industry, from medicine and computers, to entertainment and construction. A power rating, usually in watts, determines the strength of the laser. Some lasers can cut through metal, while others merely read tiny bits of information without damaging the surface. Basically, the application of lasers can be divided into marking, etching, and cutting, or reading and scanning.

In the medical industry, carbon dioxide lasers are used in many types of surgery because they are more precise and sensitive than scalpels. Lasers remove tattoos without needing skin grafts, as well as painlessly clearing rot out of teeth. These less invasive lasers result in faster recuperation from surgeries such as removing certain tumors and correcting vision by reforming the eyeball lens. Damage to surrounding tissue, as well as bleeding, has been reduced by incorporating lasers.

Many common home or office devices house lasers as an intrinsic part of their performance. CD, DVD and Blu-Ray players use lasers to read the audio and video information on the disc, the way a needle used to read the groove of a record. CD, DVD and Blu-Ray recorders have stronger lasers that can burn the information onto the surface of the disc, either temporarily or permanently. Laser printers also utilize lasers to change a surface, in this case paper, to display text and graphics. Even at the grocery store, lasers scan the barcode on your packages to tell the computerized register what you're buying and how much it costs.

Lasers of the appropriate strength can etch surfaces from plastic to rock. Some companies inscribe a minute identification number on diamonds to keep track of them. Tombstones made of granite or limestone are carved with powerful lasers. Numerous metal pieces can be precisely cut out, drilled, and welded together to make a finished product using lasers capable of melting metal.

Even though the first laser was made in a laboratory back in 1960, it took several decades to apply this tool to various technologies. Now, lasers are indispensable to our daily lives. Visible lasers have even replaced strings, levels, and stakes in surveying equipment. Everyone should be treated to a laser show inside a planetarium, where colored lasers of all widths simulate the night sky.

What Is an Elmo™ Projector

An Elmo™ projector is a document camera and projection system that is commonly used as a descriptive name for all such systems, regardless of who manufactures them. This is not a correct use of the term and many companies fear when a situation like this develops that they could actually lose the value of their name. In most cases, if the brand is unknown, using the term document camera or document projector instead of Elmo™ projector is advisable.

The main purpose of an Elmo™ projector is to display documents and other objects that are not translucent -- in other words, documents that are not made with transparencies. These documents require a video camera and projection lens in order to work properly. The Elmo™ camera is usually digital. However, they are able to display more than just documents. In many cases, they can be used to display three-dimensional objects as well, though they will be rendered in two dimensions on the screen.

The thought behind the Elmo&trade projector is similar to that of the overhead projector, which came into widespread use during the late 1950s and continued through the 1990s. Such projectors were useful in making materials available to a wide audience in a classroom or group setting, but could only display documents put on transparent material. While duplication to transparencies is easily done, it required an additional step. Further, three-dimensional objects could not be displayed. They would instead be rendered as a black shadow in the area where they were blocking light from passing through.

The document projector changes all of those limitations. In fact, it is not only possible to display documents and objects on an Elmo™ projector, it is possible to even display moving pictures, such as movies. However, this is, by no means the most effective way of displaying such media. The camera used for a document projector does not operate with as many frames per second as standard video cameras. Thus, any movement would appear jumpy. That is one reason they are often called Elmo™ document cameras. It is understood that motion is not important in displaying documents.

Likewise, when looking at three-dimensional objects with Elmo™ document cameras, they should be kept still, or moved very slowly. Often, this is not a problem. If another side of the object needs displayed, it can simply be moved to face the camera. In such cases, the motion is not important and is only used to facilitate the change in the point of view.