Introduction
The video projectors allow the display of the screen the computer (or other device) in a manner enlarged on a wall or on a screen appropriate. In this way, it is possible to all are present in the environment to watch presentations show, photo sequences, videos, etc. By be a device so useful, the projectors are easily found in businesses, schools and universities for meetings, presentation of academic papers, etc.
For be a useful device, but also expensive, the AbbreviationFinder shows the following the main characteristics of the projectors video, so that you know enough about these devices at the time of buying them.
Main features of video projectors,
Brightness (brightness)
A video projector (also called data-show uses a cannon of light to display images from a computer(or another device that generates images) on a wall or on a screen. So that the displayed images are not erased, or difficult to be seen in environments reasonably enlightened, it is necessary to that has a good rate of luminance.
By being standardized by the ANSI (American National Standards Institute), the evaluation of this feature it is done through a measure called “ANSI lumens”. Of course, the higher this ratio in a projector, the greater will be the brightness of his cannon of light.
To get a picture with a sharpness satisfactory, even in environments very spacious (a hall party, for example), it is recommended to use a date-show that has a 1,500 ANSI lumens or more. This condition is especially valid when if you want to have the maximum possible magnification of the displayed image.
In small environments, such as a meeting room, or a room class, you can use, comfortably, a project that has between 1,000 and 1,500 ANSI lumens.
Note that, along with the brightness, it is recommended to check if the device has a good contrast ratio. The higher this ratio, the better. Prefer projectors that have, at least, a contrast of 500:1.
Resolution
As well as on the video monitors, the resolution of a projector can affect the quality of the image. The higher the resolution, better is the definition of certain displayed objects.
For slide presentations using software such as PowerPoint or Impress, for example, an 800×600 resolution is enough for most cases. Already for images that display many details, such as a table containing many values or maps with a lot of information, a resolution of 1024×768 if it shows more appropriate. A resolution greater than this only it is recommended when there is a lot of information being displayed, such as the floor plan of a building, for example.
To obtain the best imaging results, try to leave the resolution the computer’s video card to the same value of the resolution of the projector.
The size of the image
The size of the screen ideal for a projection depends on the size of the environment. The larger the site is, the greater should be the size of the image, for people located in the background does not have difficulties in the preview.
A way to adjust this feature is increasing or by decreasing the distance of the data show from the wall or screen. As shown in the image below, the farther away the device, the larger the size of the image.
It is important to note, however, that the brightness decreases as the projector gets further from the display area. If the contrary is done, the image becomes with more brightness. For this reason, the projectors usually indicate in their manuals the distances maximum and minimum with which they work.
Almost all projectors come with a button that allows you to to regulate the magnification of the image, in addition to another that allows you to adjust the focus, since this changes when there is a change the size of the image.
Lamp
The video projectors to last very if well taken care of, but the lamp the light source usually takes less. For this reason, it is recommended purchase appliances of brands that offer a network of assistance technical reasonable to that is possible to find lamps replacements and, when necessary, other parts spare.
To increase the life time of the lamp, strictly follow the recommendations that the manufacturer provides in the manual of the device. In general, the following care help (and serve to protect the projector as a whole):
– Position the unit to prevent it from falling, and be careful when transporting it;
– Wait for the appliance to cool before storing it in its carrying case;
– Avoid turning on and off the projector very quickly.
The lamps of projectors, the most ancient support of 300 to 500 hours of use. Today, it is possible to find lamps that last for at least three thousand hours.
Technologies
Technologies the most common existing (up to the date of publication of this article) for the projectors are: DLP, LCD and LCOS. All are displayed quickly the following:
DLP (Digital Light Processing)
Technology DLP uses a chip called DMD (Digital Micromirror Device) that contains thousands of mirrors to microscopic controlling the state of each pixel of the image. These mirrors are turned off and on quickly to the generation of the image. When a set of mirrors is in the “off” state (off), for example, the pixels represented by this set are dark.
The DLP projectors more current use three-chip DMD to manage the colors are generated, each of which controls one of the following colors: red, green, and blue. A prism is used for the images that require a mixture of colors.
In turn, the apparatus more simple make use of only one chip, and the control of the colors is done by a disk that contains the colors mentioned and a blank area that serves to manage the brightness. This disk rotates synchronously to the movements of the mirrors of the DMD to display the correct color.
If you choose a DLP projector, you prefer the models that work with three chips, because in addition to being more sophisticated, they are able to view more colors.
LCD (Liquid Crystal Display)
Projectors that use the technology LCD have functioning similar to projectors that use the default DLP, with the difference that, instead they use an array of mirrors microscopic to treat of the passage light, use panels of liquid crystal whose components sound activated on/off by means of electrical charges.
In fact, this technology usually receives the name of 3LCD when applied in projectors, since they usually uses a panel of LCD for each color scheme RGB (Red, Green, Blue, red, green, and blue). A prism is used for images that require a mix color.
Generally, one uses an LCD technology called HTPS (High Temperature Poly-Silicon), type characterized by be highly reliable and able to work with large images and high contrast, even when made up of small panels.
LCOS (Liquid Crystal on Silicon)
Technology LCOS uses an array of liquid crystal to represent the pixels of the image. This array is positioned over a layer of mirror reflective, which is fixed on the surface a chip (here it is also possible to use a combination of three chips, one for each color scheme RGB). In the generation of the image, the light is emitted from the mirror to the array of crystal net. Electrical loads act on these crystals, activating them (or disabling them) to allow the passage of light to the projection lens.
It is possible to note that the LCOS is a kind the mix of technologies DLP and LCD. The main drawback of this type of projector is the price. Because they are manufacturing more complex and be able to work with large images without lose the quality, the devices LCOS is the most expensive in the market.
Extra features
A another important feature to be observed in projectors is your amount of connectors. The variety allows you to connect the data show a greater range of devices. The most common entries are: VGA, S-Video and RCA. With the popularization of video cards with DVI, it will probably be common to find a projector with this the type of connector. Learn more about video connectors here.
It is also common to find video projectors, accompanied of remote controls. This type of device is useful in various situations, for example, when it is necessary set up a projector that is stuck on a support in the ceiling or when it is necessary to hide a slide in a given time.
Some projectors come with speakers simple, but this already is not a feature as important as that the quality of the audio and the volume tend to not be high. In any case, the speakers can “break a twig” in the situations in which, for some reason, there is no speakers to be used.
If you want to use a projector for the display of videos, consider purchasing a model that has features that optimize the display of images of this type of application.
Ending
A video projector is a device of high price, many times, more expensive than laptops, for example. Therefore, it is important to note the characteristics mentioned above, and analyze which are most important for your case.
In relation to the technology (DLP, LCD, or LCOS), the choice is not so easy. If you want to something a bit more sophisticated, surely the projectors with LCOS that are the the most indicated, but are also the most expensive. The projectors DLP and LCD had some disadvantages: the preview multiple colors in certain images (rainbow effect) and an effect of “grades” caused by the separation of the pixels, respectively. But, nowadays, these problems already are almost imperceptible, therefore, it is an error consider that the technologies DLP and LCD are obsolete.
In more, the AbbreviationFinder hopes that this article will help you choose the best projector for your needs.
