Today, projectors are widely used in homes and various organizations, information output devices are used to transmit images to a special canvas used as a screen. Thanks to this, the projected picture is large and pleasing to the eye. They are slightly inferior to TVs in image quality. The market is now awash with projectors for every taste. When choosing such an electronics, you need to know exactly what tasks will be set for the device. After all, modern models differ from each other not only in class and scope, but in picture output technologies. Information about the design of the projectors and their operation can help in choosing.
Projector Types
Most often, when we hear about projectors, we present a gadget that is installed in a certain place. This type of device for displaying information on a vertical plane is very popular, although it is by no means the only one. Stationary devices, as a rule, are equipped as much as possible, since manufacturers are not limited by the size of the case. They are difficult to take with you, but the user gets a powerful technical stuffing. There is a portable type of device, these projectors are easy to carry for presentations in different places. They have good characteristics combined with compactness. The functional set is also here at a good level.
But manufacturers do not stop there, trying to make the size of the devices even smaller. The result of which was the emergence of pocket-sized devices and projectors for mobile devices with the smallest dimensions. The weight of the first does not exceed the mark of 300 grams. For those who are in motion, a model that fits in your pocket is a real find. However, to ensure high portability, the technical component is slightly cut. The smallest models are able to connect to smartphones, which allows you to display an image from the phone screen. They are distinguished by ease and ease of use, but their useful functions are very limited.
Areas of use
Projectors are also classified into office and home. Apparatuses for home display a widescreen picture with high contrast and realism, and also have high-quality sound, due to which you can enjoy watching films that can completely immerse the viewer in the thick of things. The size of the light flux in this case is of secondary importance. As for gadgets for working in an office environment, they are more versatile.
What is the difference between home projectors and office projectors?
Home projectors differ from office projectors in some respects, of which it is worth highlighting the following:
- screen format;
- connectors and their purpose;
- performance;
- body weight;
- color rendition;
- noise level and lamp life;
- built-in speakers.
Device and principle of operation
The design of projectors for the most part differs little. The technical arsenal of the multimedia device consists of an optical system, an image modulator, a lamp, cleaning and cooling systems, as well as electronic filling. A light device, which, in essence, is a projector, redirects light from a lamp with a concentrated stream to the required plane. These are quite complex devices in content, conditionally divided into two categories. The first includes models with CRT-technology for image acquisition, equipped with cathode ray tubes in the amount of three pieces, and the second - DLP, LCD and LCoS devices working using a fixed matrix structure. The latter are more popular as they provide higher quality. As a rule, ZOOM lenses are included in the device of multimedia projectors, thanks to them the image size changes without the need to move the device itself. In some models, the focal length is changed using the remote control, and in others - by manually adjusting the lens. The latter method is not so convenient, but it makes tuning more accurately.
In most cases, metal halide lamps are used that can emit more light flux than halogen lamps with a similar power. But by the end of their service life, their efficiency is halved. Also used in the device of projectors are projection-type lamps with low energy consumption and high light flux, they differ in a more natural spectrum. In modern projectors, very durable light sources are installed, the life of which can vary from 1000 to 4000 hours. In order to timely replace this element, a counter is provided in each device.
Optics is responsible for redirecting light to the display panel. It includes components such as mirrors, prisms and projection lenses. Image modulators are responsible for the brightness level, resolution and speed; today, DLP, LCD, LCoS and CRT systems are used, and they will be described in detail below. An important role in the device of the projector belongs to cooling, the fan is very important for normalizing the temperature of the lamp and electronic circuit boards. To interact with multimedia sources , projectors have the necessary connectors on the case - VGA, DVI, HDMI and others. Many models also come with a USB port and Wi-Fi support.
DLP projectors
In such devices, the role of the nucleus is performed by a special matrix that forms the image. Each mirror easily responds to an incoming signal by turning a small angle. This creates image pixels. The device DLP projectors allows them to display a picture with high contrast and with more detailed shadows, which is the main advantage of the technology. Models equipped with such a system show their best in terms of durability and reliability, especially in comparison with devices of the past generation. The downside is the high cost of this type of projectors.
LCD systems
In most situations, devices equipped with a triple of liquid crystal matrices of blue, green and red are used. A powerful stream of light coming from the lamp breaks through them. Thus, an image is displayed on the screen. This technology has a lot of advantages, including the ease of design and ease of use of individual components. LCD projectors create a high-quality picture, characterized by realism, color saturation and stability. But the owners of such devices may also encounter shortcomings, in some instances there is an unpleasant visual effect resembling a wire mesh.
Projectors with LCoS Technology
This type of projectors appeared not so long ago. The strengths of this technology, first of all, include high definition without the effect of "mesh". Other features also deserve attention. Such devices are based on an LCoS matrix, which is a liquid crystal on silicon. In terms of popularity, this technology is inferior to LCD and DLP. But due to its unique features, it has good prospects. Due to the use of LCoS crystals, the image is obtained according to the reflective principle, and not the translucent one, as can be seen in LCD devices. The reflective matrix responds to the impact faster, three times faster than the transparency technology. In addition, the design features of LCoS panels allow more efficient use of the crystal surface, which makes it possible to increase the number of pixels without the need to enlarge the panel. And this directly affects the quality of the picture. The design of LCoS projectors is not very complicated, which means that they are cheaper to manufacture because there are no mechanical elements.
CRT projectors
This technology is a pioneer in the field of projectors. The first instance with this image output system appeared back in 1970. Such devices are based on three cathode ray tubes having red, green and blue light filters. They are responsible for the formation of the light flux passing through the focusing lenses; it enters the screen in the form of a full-color picture. Today, CRT devices are becoming less common, giving way to more modern counterparts. The peak of popularity of this technology is left behind. However, it surpasses newer technologies in many ways, namely in color reproduction, resolution, lamp life, and acoustic noise. Its weaknesses are the complexity of the setup and the bulkiness of the models where it is used. In addition, it is characterized by a low level of brightness, so for viewing it is necessary to turn off the lighting.
Pros and cons of projectors
Projectors offer a large screen size, which is a weighty argument in favor of buying this device. You can bring information to more people. It all depends on the preferences and size of the room. The larger the image, the brighter the impression. If the monitor may have black bars due to different video formats, then there will be no such problems with the projector. It is easy to customize the screen for any format. Digital projectors often include support for 3D images without loss of quality. If you create a suitable environment by darkening the room, you can get an image better than in the LED monitor.
Disadvantages are also available. The most expensive element of the projector is a lamp, and it becomes unusable about once every 4 years. Its replacement will entail considerable financial costs. The projector is significantly noisy due to the active cooling of the lamp. When watching a video or slide show, you have to endure the sound of working fans.
Criterias of choice
There are many points that you should pay attention to when searching for a suitable projector; an image output device always needs a good brightness level. Although the operating conditions have a great influence on this indicator, it’s good if there is a choice of modes, often there are three of them - “Presentation”, “Film” and “Dynamic”. The color saturation is also worth a look. Three-matrix projectors give a more natural image, surpassing single-matrix devices in this respect. You need to look at the level of contrast. This option is especially important if you need a home theater. The last, but no less important point is the resolution of the picture, which affects the clarity of the picture.
Conclusion
Modern projectors are quite complex devices, but at the same time they can become an indispensable thing both in the business sphere and for use at home. They are able to give viewers vivid emotions from viewing due to qualities that are not available on TVs or monitors. The main thing is to approach the choice wisely.