A multimedia projector is a miracle of technology of the 21st century, a very useful and multifunctional device. In an apartment you can organize a full-fledged home theater, because the projection of the image allows you to view video on the screen in the entire wall. Using the projector for educational purposes makes it possible to broadcast video in a wide format for better assimilation of information by students. In the framework of this article, we will try to understand the principle of operation of various types of projectors, consider the technical characteristics of the devices, and also give recommendations for choosing a more practical model.
What is a multimedia projector?
A multimedia projector is a device that projects an image or video from an external source onto a large screen. The source may be removable media, a computer, or another device having an operating system. The development of technology has given additional functions to projectors. Now you can find models that synchronize with the storage medium via a wireless Wi-Fi network. It is very convenient and practical.
We name the main characteristics of multimedia projectors. The undoubted advantage of these devices is the size of the projected screen. If we compare the device at a cost with a TV whose screen has the same dimensions, then the projector wins. The minimum price of the device, intended for home use, varies between 14,000-30,000 rubles.
Image quality largely depends on the technical specifications of the multimedia projector and screen properties. The canvas should have a high reflectivity, then the image will be sharper and sharper. To get a saturated picture, you need to remove all extraneous light sources in the room.
Before viewing the recording from removable media, some preparatory work is necessary. The projector is connected to a storage medium, to a sound system. The projector screen specifications must meet certain requirements. Adjusts the sharpness of the image on the screen. Some models make extraneous sounds when working, this creates inconvenience when watching a movie. The noise comes from the cooling system built into the projector.
The stationary projector is most often mounted on the ceiling. If the model is portable, then it is most convenient to place it on a pedestal or table. To start using the projector, you must turn on the device and adjust the image by adjusting it at the corners until you get the correct rectangular projection screen.
Projector classification
Currently, there are a huge number of projectors, which significantly differ from each other not only in cost and functionality, but also in technical characteristics, manufacturing techniques of internal parts and profile purpose. Imagine a classification of types of projectors. According to their functional purpose, projectors are divided into 3 groups:
- Home cinema. These devices are intended for home use. Characteristics of home projectors budget line have the most basic functions. The devices are easy to operate, are in the average price range. Screen size can reach two meters in diagonal. The projector has connectors for connecting to a personal computer, laptop or game console. In the absence of the necessary connectors, special adapters can be used to synchronize devices. These models of projectors also have a number of disadvantages: low brightness of lamps, low level of definition in budget models.
- Projectors for movie theaters. These are professional powerful devices that project an image onto the widescreen screen of cinema halls. Such projectors have a very high cost.
- Projectors for study and business. They are used in educational institutions and at enterprises with the aim of delivering information for familiarization. The characteristics of projectors for schools differ in their affordable cost. The projection of the screen can reach 7 meters diagonally. Some models feature a built-in speaker.
- 3D projectors.
Innovative devices that project a three-dimensional image. Such devices are used in the film industry, in educational institutions, as well as in museums and in organizing exhibitions.
Depending on the design of the modulator, projectors are divided into:
- TFT projectors. The modulator is represented by a small-sized color LCD matrix made using TFT technology. The distribution of light in the matrix is carried out by a condenser, which is a system of lenses.
- Polysilicon projectors. To project the image, three monochrome matrices are used (red, blue, green). The optical system combines images from three matrices and you get a high-definition color picture. For the distribution of light, special built-in mirrors are used that direct the same amount of light to each of the three matrices.
- DMD projectors. Built on a reflective system. A DMD matrix consists of a large number of micromirrors that can reflect the incident light on the lens or in the absorber. Thus, an image is formed on the screen.
According to the modulator lighting method, the following types of devices are distinguished:
- Translucent type. Passing light flux undergoes modulation, which leads to strong heating of the matrix. For cooling, a fan is installed in the projector housing, which makes noise during operation.
- Reflective type. The luminous flux is reflected and sent to the matrix. This does not cause strong heating, which means that installing a serious cooling system is not necessary.
Types of projectors and their characteristics
The clarity of the picture and the drawing of the image largely depend on the resolution of the file being played from the media. In addition, the quality of the projected image depends on the technical characteristics of the projector, as well as on the technology for constructing the projection, the characteristics of the lens and resolution.
LCD technology
Light passes through a liquid crystal panel, which consists of a large number of pixels controlled by electrical signals. A different amount of voltage is applied to the pixels, which controls the transparency level of an individual pixel, which means that the brightness of each point on the screen changes. This is how an integral projection image is formed.
This technology has significantly reduced the size of projection devices and reduce the cost of them. The maximum light intensity at the same time began to reach 10,000 lm.
This technology has some negative aspects. The liquid crystal matrix begins to degrade and age over time. Depreciation will adversely affect image quality. Dead pixels may appear on the matrix. During operation, the device heats up very much, therefore, for cooling, a powerful fan is built into the case, which creates a fairly loud noise. Bright and powerful lamps of such projectors have a high cost.
CRT Technology
One of the first technologies for the manufacture of projection devices, which has been used for several decades. We list the main characteristics of multimedia projectors created using this technology. The projection principle is based on a cathode ray tube. Image quality may be more advantageous than projectors of other technologies. Black color is saturated, contrast is good. The duration of continuous operation can reach 10,000 hours.
Viewing is possible only in a darkened room, since the maximum brightness level does not exceed 300 lm. Devices manufactured using this technology are distinguished by their massiveness and large dimensions. The device can weigh several tens of kilograms. And setting up the device is so complicated and time-consuming that sometimes it requires expert help.
The principle of the projector is as follows: the signal is divided into components of three colors (red, blue, green), the beam intensity changes. Light passing through a magnetic field scans the surface of the screen. A monochrome picture is created on the screen, the image of which is projected onto the screen. As a result, three projections are connected, and a color image is obtained.
D-ILA Technology
Devices manufactured using this technology are also equipped with LCD elements, but not of a translucent type, as in LCD technology, but reflective. The light-modulating layer is located above the single-crystal silicon substrate. It is in it that the matrix control scheme is located. This gives a significant advantage over LCD matrices, as smaller matrices are able to give a higher resolution. There is no pixel grid on the projection of the picture.
The principle of operation is the same as that of LCD matrices: the matrices create three-color images and project the image through the lens onto the screen. The devices are distinguished by their small size. Projection onto wide screens is possible without loss of image quality. There are also negative aspects: expensive lamps, the appearance of dead pixels, the lack of information about the duration of service of such devices due to the novelty of the technology.
DLP Technology
The matrix is represented by a large number of small mirrors that are able to change their position. Each mirror can project light either onto a screen or into a light absorber. It turns out black and white colors on the projection. When the mirror changes its position with high frequency, we get shades of gray. To separate other colors, a color disk is used, which has light filters. It is precisely because of the rotation of the disk that the "rainbow effect" can be observed on the screen. The color wheel in some models may have additional colors - yellow, cyan, magenta. There is also a transparent segment that plays the role of producing a pure white projection color.
The brightness of a black-and-white picture is especially important for devices that are used to demonstrate presentations or diagrams. On some models, as the light brightness level increases, the picture becomes dimmer.
Three-matrix projectors manufactured using this technology work on the principle of superimposing three RBG monochrome images to obtain a full-color image. Such devices have a high level of brightness, which can reach 18,000 lumens. The winning features of this type of device are as follows: small size, durability, low noise, high brightness. The disadvantages include an expensive lamp replacement, the possible appearance of broken pixels, the "Rainbow Effect" in single-matrix models.
Laser projectors
One of the latest imaging technology is laser. These devices are distinguished by high cost, good performance and the highest level of quality of the projected image. Continuous laser operation can be carried out for 20,000 hours. Let's consider some characteristics of laser projectors. The brightness of 4500 lm will allow you to view video even in a room that has additional light sources. Ultra-focal lenses of laser projectors allow you to place the device in close proximity to the projection screen.
The principle of operation of the device is similar to the previous ones. The laser generates three monochrome images that overlap and mix. A system of mirrors takes part in creating a focused image. Laser projectors can project images on huge screens, while the image will be very saturated and bright, and the color rendering realistic. The screen surface does not have to have high reflective properties.
Projector Lamps
The light source for projection is the lamp integrated in the projector. Power of a light stream is measured in lumens. Currently, there are models that can produce 60,000 lumens. If we consider projectors of minimum power, it is worth noting that in some budget devices there are LED lamps that give out a luminous flux of hundreds, or even tens of lumens.
In home viewing conditions, a projector with a luminous flux of 1000-1500 lumens is enough. In the absence of other light sources, the quality of the projected image will be acceptable. In rooms with additional lighting, more powerful projector lamps are required.
If the lamp in the projector burns out, it is best to replace it with the original one. But sometimes it is not possible to find an identical lamp, then you can use similar analogues, which are more affordable in terms of price and availability in stores. Let's consider some options and the main characteristics of lamps for projectors.
- Metal halide lamps. A kind of high-pressure discharge lamps. Radiation of light occurs due to the action of metal halides on mercury vapor. The light is very bright, and the lamp itself consumes a small amount of energy. Over time, the light becomes dimmer.
- Gas discharge lamps. Built on the processes of electric discharge in gases. The characteristics of the lamps for projectors have some differences depending on the materials used. They are characterized by high light output - up to 55 lm / W.
- Xenon lamps. Light emits a metal arc located in a bulb with xenon. The lamp gives a bright white light, which is as close as possible to daylight.
- LED lamp. Used in budget projectors. It produces a small level of light, only a few tens of lumens.
- UHP lamps. Glow occurs due to the creation of an electric discharge in mercury vapor. The lamp is small and gives a very bright glow.
- P-VIP lamps. A kind of halogen lamp. They have a high level of brightness and a long service life.
Projectors Sony. Models and reviews
The lineup of Sony projectors has several dozen models.
SONY VPL-HW65ES
Projector designed for home use. We list the main characteristics of this multimedia projector. Maximum image quality - Full HD. Luminous flux - 1800 lm. The device is small, mobile. The projection image is distinguished by brightness and color saturation. Lamp life reaches 6000 hours. Manual adjustment of the lens allows you to use the projector in different places. Price: 240 000-260 000 rub.
Positive feedback: a convenient device of small size, good picture quality, can be used in partially lit rooms.
Negative reviews: high cost, no glasses included.
SONY VPL-VW1000ES
The main features of a multimedia projector are as follows. The device is equipped with a heavy-duty lens, which allows you to view the image in 4K resolution. The issued brightness - 2000 lm. For home use, such a luminous flux will allow the device to give out saturated and contrasting colors. Using this unit, you can view 3D videos. Price: 1 000 000 rub.
Positive feedback: perfect image, small size of the device, no noise during operation.
Negative reviews: very high cost, rather suitable for professional use.
SONY VPL-SW235
Thanks to 3LCD technology, the projected image has a high clarity and contrast ratio. The projector has the following technical specifications: maximum resolution 1280 * 800, light output 3,000 lm. There are 3 brightness modes. You can connect the projector via the USB port, without the need to install additional drivers. There is the possibility of wireless synchronization. Price: 63 000 rub.
Positive feedback: there is a remote control function from the iOS device through the application, good image quality, the ability to install the projector at a distance of 79 cm from the screen.
Negative reviews: high cost, only stationary installation of the device.
SONY VPL-SW630
The type of device is a widescreen three-matrix LCD projector. The maximum resolution is 1280 * 800, the luminous flux is 3100 lm. Designed for office or home use. There are VGA, HDMI connectors. Price: 61 000 rub.
Positive feedback: good image quality in the absence of light, no noise.
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Epson.
EPSON EB-W42
LCD, TFT, 1280*800. 3200 , Wi-Fi. . Price: 55 000 rub.
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EPSON EB-X41
- LCD, - TFT, - 3200 . USB-. HDMI VGA. : 34 000 .
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EPSON EB-S05
LCD. 800*600, 3200 . VGA HDMI . . , , . Price: 24 000 rub.
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EPSON EB-X05
- LCD. 1024*768, 3300 . VGA HDMI. , . : 26 000 .
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LG.
LG PH30JG
, 0,49 . : - 1280*720, 720 . Wi-Fi. USB-. : 40 000 .
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LG HF85JS
. . - Full HD, 1500 . . 12 . : 130 000 .
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LG PH450UG
DLP. 1280*720, 450 . 3D, . . Bluetooth Wi-Fi. : 45 000 .
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Acer.
Acer X118
DLP Projector The maximum resolution is 800 * 600, the luminous flux is 3600 lm. There is a VGA input for connecting the device to a computer. It is recommended to use the device in an office or school. Price: 19 000 rub.
Positive feedback: low cost.
Negative reviews: can only be used in a dark room, short lamp life, image grain.
Acer H6517ABD
DLP widescreen projector. The color wheel is six segmented. Maximum resolution Full HD, light output 3400 lm. Ports for connecting storage media - VGA, HDMI. The device belongs to the category of office equipment.
Positive feedback: low cost, there is an economical mode of energy consumption.
Negative reviews: poor video image quality, poor projection quality in extraneous light, extraneous noise.
Acer c120
DLP matrix technology. The maximum resolution is 845 * 480, the luminous flux is 100 lm. The device gives an image with a diagonal of up to 2.5 m. Connection is via the USB port. Weight - 180 g. Price: 16,000 rubles.
Positive feedback: A very small and lightweight portable device, great for presentations.
Negative reviews: there are no HDMI and VGA connectors, poor video playback quality even in a dark room.
Acer h7850
DLP matrix manufacturing technology. The maximum resolution is 3840 * 2160, the luminous flux is 3000 lm. Connection is via HDMI, VGA, USB. The device has 2 built-in speakers. Price: 125 000 rub.
Positive feedback: high quality resolution and color reproduction, it is possible to use both portable and stationary.
Negative reviews: high cost for this functionality, no wireless synchronization, no 3D function, short lamp life. High image quality requires enhanced projector screen specifications.
How to choose a projector
When choosing a projector, the buyer always doubts which model should be preferred. In order to make the right choice, you need to understand the main characteristics of the projectors. How to choose the right device and select the necessary functionality, we will understand in more detail.
The reason for doubt when choosing is the lack of awareness and knowledge about certain technological features of the devices. Consider the options for projectors that are best suited for specific purposes.
If you select a projector exclusively for home use, then choose a model of a well-known brand, and not a Chinese counterpart, which will have a lower cost. In addition to cost, you should pay attention to such parameters as:
- The maximum resolution. If you are not going to project the image on a very wide surface, then 800 * 600 quality will be enough for you, it is better to take models that produce HD or Full HD quality.
- Light flow. The valid range for the home version is 1000-2000 lm. At the same time, you can allow a little light in the room in which the image is projected. Projector power is a feature that is one of the most important performance indicators.
- Type of projection lamp. Some lamps can last up to 30,000 hours. If you plan to use the projector frequently, then the quality of the lamp will be an important factor.
- Noise level. There are projectors whose fans are so loud that they interfere with the perception of the film itself. The volume of the device is indicated in the technical specifications, it is measured in decibels.
- Color rendering. The color scheme should be natural and realistic.
- The limit of contrast. Choose a machine with a contrast limit range of 1000: 1 or 2000: 1. If this parameter is lower, then darkened images will be difficult to distinguish.
- Connection Methods. Some models do not have running slots for connecting an information source, since synchronization occurs exclusively wirelessly via Wi-Fi.
Given all the nuances, you can choose the device that is ideal for your needs. When you decide on the necessary parameters, it will become clear how to choose the characteristics of the projector.
Finally
A large variety of projector options presented on the domestic market is too expensive. If you read the article to the end, then you should understand what characteristics you should pay attention to when choosing a projector.