Today, projectors are widely used in homes and various organizations, information output devices are used to broadcast images on a special canvas used as a screen. As a result, the projected image is large and pleasing to the eye. In terms of image quality, they are slightly inferior to TVs. The market is now flooded with projectors for every taste. When choosing such electronics, you need to know exactly what tasks will be assigned to the device. After all, modern models differ from each other not only in class and scope, but in image output technologies. Information about the design of projectors and their operation can help in choosing.
Types of projectors
Most often, when we hear about projectors, we imagine a gadget that is installed in a certain place. This type of device for outputting information to a vertical plane is in great demand, although it is by no means the only one. Stationary devices, as a rule, are equipped to the maximum, since manufacturers are not limited by the size of the case. Themdifficult to take with you, but the user gets a powerful technical stuffing. There is also a portable type of device, these projectors are easy to carry for presentations in different places. They combine good performance with compactness. The functional set is also at a good level here.
But manufacturers do not stop there, trying to make the size of the devices even smaller. The result was the appearance of pocket-sized devices and projectors for mobile devices with the smallest dimensions. The weight of the first does not exceed 300 grams. For those who are on the move, a model that fits in your pocket is a real find. However, to ensure high portability, the technical component is cut down a bit. The smallest models are capable of connecting to smartphones, which allows you to display an image from the phone screen. They are lightweight and easy to use, but useful functions are severely limited.
Applications
Also, projectors are classified into office and home. Devices for the home display a widescreen picture with high contrast and realism, and also have high-quality sound, due to which you can enjoy watching movies 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 the office, they are more versatile.
What is the difference between home and office projectors?
Home projectors differ from office projectors in several ways, of which the following should be highlighted:
- screen format;
- connectors and their purpose;
- performance;
- body weight;
- color rendering;
- noise level and lamp life;
- built-in speakers.
Design and principle of operation
The majority of projector devices differ little. The technical arsenal of a multimedia device consists of an optical system, an image modulator, a lamp, cleaning and cooling systems, as well as electronic filling. The light device, which, in fact, is a projector, redirects the light from a lamp with a concentrated flux to the required plane. These devices are quite complex in terms of content, conditionally divided into two categories. The first includes models with CRT imaging technology equipped with three CRTs, and the second includes DLP, LCD and LCoS devices operating using a fixed matrix structure. The latter are more popular because they provide higher quality. The device of multimedia projectors, as a rule, includes ZOOM lenses, thanks to them the image size changes without having 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 the setting more accurate.
In most cases applymetal halide lamps capable of emitting more luminous flux than halogen lamps of the same power. But by the end of their service life, their effectiveness is halved. Also used in the design of projector lamps are projection-type lamps with low power consumption and high light output, they have a more natural spectrum. Modern projectors are equipped with very durable light sources, the resource of which can vary from 1000 to 4000 hours. In order to timely replace this element, a counter is provided in each device.
The optics are responsible for redirecting the light to the display panel. It includes components such as mirrors, prisms, and projection lenses. Image modulators are responsible for the level of brightness, resolution and speed, today DLP, LCD, LCoS and CRT systems are used, they will be discussed in detail later. An important role in the projector device belongs to cooling, the fan is very important for normalizing the temperature of the lamp and electronic boards. To interact with multimedia sources, the projectors have the necessary connectors on the body - VGA, DVI, HDMI and others. Many models are also equipped with a USB port and Wi-Fi support.
DLP projectors
In such devices, the role of the core is performed by a special matrix that forms the image. Each mirror easily responds to an incoming signal by turning through a small angle. This creates pixels in the image. The design of DLP projectors allows them to display a picture with high contrast and with moredetailed shadows, which is the main advantage of the technology. Models equipped with such a system show their best side in terms of durability and reliability, especially in comparison with devices of the previous 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 colors are used. A powerful stream of light emanating from the lamp breaks through them. Thus, an image appears on the screen. This technology has many advantages, including ease of construction and ease of operation of individual components. LCD projectors create a high-quality picture, characterized by realism, color saturation and stability. But owners of such devices may also face disadvantages, in some instances there is an unpleasant visual effect resembling a wire mesh.
Projectors with LCoS technology
This type of projector appeared not so long ago. The strengths of this technology, first of all, include high definition without the "grid" effect. Other features also deserve attention. Such devices are based on the LCoS matrix, which is liquid crystals on silicon. In terms of prevalence, this technology is inferior to LCD and DLP. But due to its unique features, it has good prospects. Through the use of LCoS crystals, an image is obtained according to the reflective principle, and nottranslucent, as can be seen in LCD devices. The reflective matrix responds faster, three times faster than translucent technology. In addition, the design features of LCoS panels allow more efficient use of the surface of the crystals, which makes it possible to increase the number of pixels without the need to increase 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, since 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 with 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 rarer, giving way to more modern counterparts. The peak of popularity of this technology is behind us. However, it outperforms newer technologies in many ways, such as color reproduction, resolution, lamp life and acoustic noise. Its weaknesses are the complexity of the settings and the bulkiness of the models where it is used. In addition, it has a low level of brightness, so you need to turn off the lights to view it.
Pros and cons of projectors
Projectors offer a large screen size, which is a powerful argument infavor of purchasing this device. You can get the information out 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 can have black bars due to different video formats, then there will be no such problems with the projector. It is easy to adjust the screen to any format. The device of digital projectors often includes support for 3D images without quality loss. If you create the right environment by darkening the room, you can get a better picture than an LED monitor.
There are also disadvantages. The most expensive element of a projector is the lamp, and it breaks down about once every 4 years. Its replacement will entail considerable financial costs. The projector makes a noticeable noise due to the active cooling of the lamp. When watching a video or slideshow, you have to endure the sound of running fans.
Selection criteria
There are many things to consider when looking for the right projector, the output device always needs a good level of brightness. Although this indicator is greatly influenced by operating conditions, it is good if there is a choice of modes, often there are three of them - “Presentation”, “Film” and “Dynamic”. Color saturation is also worth looking at. Three-matrix projectors produce a more natural image, surpassing single-matrix devices in this respect. You also need to look at the contrast level. This parameter is especially important if you need a home theater. Last but not leastthe moment 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 for both business and home use. They are able to give viewers vivid emotions from viewing due to qualities that TVs or monitors do not have. The main thing is to choose wisely.
