What is an LED Projector or LED Projector? LED projectors: reviews of manufacturers and review of the best models LCD technology in projectors.

A multimedia projector has long become a common gadget for offices, presentations, meeting rooms, museums, and educational institutions. Projectors are increasingly being used at home. These devices survive in a rather difficult competitive climate (plasma, LCD and laser panels are competitors to projectors), while having only one huge advantage - a large diagonal of the projected image.

The abundance of technologies used to produce projectors raises the problem of choice. As Pult.ru experts note, buyers intending to purchase a projector rarely have an idea of ​​what exactly they want, which often leads to mistakes when choosing. This post is about the main criteria for choosing projectors and the prospects for the development of modern technologies that are used in their production.

Lamps

This impressively expensive consumable has to be changed every 3-4 years, and more often with intensive use. Engineers from the world's leading manufacturers tried to solve the problem of a not too resource-intensive light source.

UHP

The most commonly used projection lamps are UHP (Ultra High Performance). The principle is simple - the lamp glows with a discharge that occurs between tungsten electrodes in mercury vapor, which is under high pressure. The main advantages of these lamps are the relatively high intensity of light radiation with a fairly compact size of the source, as well as good color rendering indicators.

The disadvantages of UHP lamps are a gradual decrease in radiation intensity throughout the entire period of operation and a relatively short service life (2000 hours). Partly, the first drawback was compensated by the addition of special reagents that promote the reduction of tungsten on the electrodes. Partially extending the life of the lamps is the use of highly purified quartz glass, which allows you to maintain a balance of the thermal energy generated during lamp operation.

HCX

HCX projection lamps or metal halide lamps, like others, produce light due to the discharge of an electric arc plasma created in a high-pressure gas. They are distinguished from UHD by the addition of certain metal halides to mercury vapor, which makes the spectral characteristics of light radiation more uniform.

The problem with these lamps is a gradual but constant loss of brightness, up to 50% during the operation of the source. The operating time of these lamps is comparable to other gas-discharge analogues.

P-VIP

P-VIP is another variation on the theme “Mercury discharge lamps for a projector.” This type can be considered the pinnacle of the evolution of mercury projector lamps. The service life of these lamps can reach 6000 - 8000 hours, the radiation intensity and spectrum uniformity are comparable to HCX, while P-VIP does not have the disease of “age-related decrease in brightness”, the lamp shines equally well throughout its entire service life. Despite the successes in extending the full life of this type of lamps, their problems have not been fundamentally solved.

Xenon

Another type of HID lamp for projectors is Xenon. As the name implies, instead of mercury vapor, the lamp contains compressed xenon. Xenon lamps are many times superior to mercury lamps in terms of power, pressure and, as a consequence, the intensity of the light flux.

The power of xenon lamps ranges from 2 to 15 kW, and the gas pressure in the lamp reaches 300 atmospheres, which predetermined their use in professional cinema projectors and extremely rarely in extremely expensive demo and home models. As they say, “All the best for children in cinemas.”

Comparison of the spectra of “xenon” and “mercury”
X axis - length in nm
Y axis - recoil
blue graph – “xenon”, red – “mercury”

Not lamps – led vs laser

Disadvantages of LED

Despite the impressive progress over the past 8 years, most LED projectors at the same cost are inferior to lamp ones in terms of luminous flux intensity. For most models, the value of the source luminous flux does not exceed 1000 -1200 ANSILm, and in most cases is within 1000. Another problem with Led projectors is the noise level during operation, which often exceeds 35 dB. However, these shortcomings are gradually being eliminated; it is worth remembering that at the time of the release of the first mass-produced LED projectors (2008 - 2009), the brightness record for the latter was 350-400 ANSILm.

Disadvantages of laser projectors

The main disadvantage of laser projectors is the price. Despite the mass production of laser projectors over the past 10 years, the price has not decreased to sane figures in the understanding of the average person. Also noticeable disadvantages of laser devices include flickering of the source and unnatural saturation of some colors. In some models, there are quite sharp transitions in the color palette, which can be annoying during prolonged viewing. It is also worth noting that some of the color rendering difficulties can be easily eliminated with additional settings.

Hybrid circuits

Increasingly, hybrid models are appearing on the market, which use both lasers and LEDs as light sources. Using this approach allows you to compensate for the shortcomings of one source with another. Most reviews and comparative tests of such systems are on par with lamp projectors, while maintaining the main advantage of alternative sources - a colossal service life. There is only one drawback - the indecently high cost.

Advantages and disadvantages of the basic operating principles

• DLP (3DLP)
• LCD (3LCD)
• LCOS (SXRD,D-ILA)

DLP and 3DLP are champions in contrast

Advantages of DLP:

• high contrast level, realistic blacks;
• high color rendering options;
• the widest range of models and manufacturers available on the market;
• more suitable for creating home theaters, due to more realistic picture transmission;
• there are no optical distortions in the older lines;
• does not require additional maintenance, protected from dust;
• can be effectively used for games and 3D.

Disadvantages of DLP:

• Quite low brightness (especially the so-called color brightness values) of budget models, which is inferior to other technologies;
• In budget models, the rainbow effect appears;
• Single-chip DLP projectors' images flicker, which is noticeable when shooting video and can be more straining on the eyes;
• Higher cost solutions with high quality images.

In fact, all the disadvantages, except for the high cost, of single-matrix DLP do not apply to projectors with three chips, the so-called. 3 DLP, which at the same time maintain high contrast as one of the main advantages.

Advantages of 3LCD:

• High brightness when comparing junior lines;
• As a rule, the convenience of adjusting the optics is higher;
• Some of the budget models can be used in darkened rooms;
• In terms of price/result ratio, they are ideal for use as an office presentation projector and educational projector for small audiences;
• Budget lines provide more realistic color reproduction (except for black and gray tones)

• Limited range, monopoly on the use of technology;
• Low contrast, unrealistic (gray) blacks;
• Vulnerability to dust, the need to replace filters by a specialist;
• Artifacts (concavity at the top) are noticeable on large diagonal screens;
• The appearance of artifacts (trails) when playing dynamic scenes in games and 3D.

In the older lines, the problem of low contrast has been solved (C2Fine technology)

Advantages of LCOS

• LCoS surpasses LCD and DLP in terms of maximum available resolution;
• Due to the placement of control elements behind the reflective layer, the “comb” effect characteristic of LCD (3LCD) is eliminated;
• The efficiency of the technology is higher than that of LCD (3LCD);
• The fill factor (the ratio of the working area to the total area of ​​the matrix) is higher for LCoS than for DLP and LCD projectors;
• Due to the use of a cooling substrate, the temperature resistance of LCoS chips is higher than that of DLP and LCD matrices, which makes it possible to create more powerful devices designed for installations;
• Contrast and blacks are better than LCD;
• Doesn't flicker like DLP;
• The response time of LCoS matrix is ​​less than that of LCD.

• Presented only in the Hi End and professional segments, which naturally affected the price; there are practically no budget models;
• The technology is monopolized by several companies, which seriously affects the product range;
• In higher segments, it has practically no advantages over 3 DLP and 3 LCD, except for the chip’s resistance to loads, while with the same image quality it is more expensive;
• They are widely in demand only for expensive installations, as highly reliable equipment.

Advantages of 3 led:

• No flicker;
• Contrast is higher than 3 LCD;
• Application of an almost eternal light source;
• No rainbow effect or other artifacts;
• High reliability.

• Low brightness level;
• Noise during operation, reaching 35 - 40 dB;
• Limited assortment: 2 – 3 projectors from a few manufacturers;
• In some cases, spectrum instability;
• High cost of few high-brightness solutions.

Main characteristics

Brightness

If necessary, calculate the luminous flux of the projector for an auditorium or room, the lighting in which complies with current sanitary and hygienic standards (a room where you can read and work, you can multiply 756 by the screen area in square meters.
Below is a table for calculating the brightness required by the projector depending on the screen area with lighting sufficient for reading.

Permission

Below are the correspondence of standards and resolutions depending on the format.

1. 4:3 aspect ratio:

• VGA (640x480),
• SVGA (800x600),
• XGA (1024x780),
• SXGA (1280x1024),
• SXGA+ (1400x1050),
• UXGA (1600x1200),
• QXGA (2048x1536).

• W XGA (1280x768 or 1280x780),
• HD720 (1280x720),
• W VGA (864x480),
• W SVGA (1024x576),
• Full HD (1920x1080),
• WUXGA (1920x1200),
• HD 4K (4096x2400).

A rarely indicated parameter that demonstrates the ratio of the minimum peripheral illumination of the screen to the maximum in the center. For movie and gaming projectors and professional devices, the uniformity value should be greater than 70%.

And a little more about contrast

Contrast has the greatest impact on image quality in dark rooms. This is largely why high-contrast projector models are used as part of home theater systems. If it is necessary to obtain a distinguishable image in illuminated interiors, you should rely on brightness.

Dry residue - what and to whom

I'll start with educational institutions, where the projector allows you to demonstrate presentations and educational films. Quality requirements are minimal, but, as a rule, there are requirements for price and, in some cases, for brightness. For rooms where dimming is possible, single-chip DLP, 3 LED or 3 LCD projectors with a brightness of 700 - 1000 ANSIlm are suitable; in rooms where there are problems with dimming, a more powerful luminous flux is needed, respectively, from 1000 ANSIlm and higher. As a rule, 3 LCD projectors win in the brightness/price ratio. At the same time, for rooms with the possibility of dimming, DLP are considered more preferable.

The choice of a business projector for presentations will also be related to working conditions and tasks, the only difference being that, as a rule, a business requires a higher resolution (HD), and the cost will increase accordingly.

For professional presentations and long-term work, laser and hybrid 3 DLP, 3 LCD and LCOS projectors can be used, which provide long-term operation and high-quality images, usually with FullHD and WUXGA, 4 K HD resolution. The luminous flux values ​​in such projectors, designed to work in illuminated rooms, as well as outdoors during the day, can reach 20,000 ANSIlm.

Despite fierce competition from LCD TVs and plasma panels, projectors are no longer exotic at home. For home theater and gaming systems, most experts recommend DLP and 3DLP projectors, since the latter distort the image less and work much more efficiently in 3D mode.

The most attractive and promising light sources in projectors are lasers and LEDs, which, all other things being equal, give a head start to others in terms of service life. Experts say that they are the future and this future is already near. According to calculations by a number of manufacturers, gas-discharge lamps will be abandoned in the next 10 years.

The material is based on the comments of experts from pult.ru, graphic materials from the sites were used: myprojector.ru, projector-lamps.ru, viking.ru, giga-line.ru, stereo.ru

P.S. The cost of projectors, depending on the purpose, varies within a very wide range; our catalog contains projectors from 19,790 to 10,452,850. If we talk about educational, office, the average cost of the latter (depending on the characteristics and technology used) varies from 19,790 to 300 000. In the case of equipment for home theaters and games, if we do not touch upon the professional and HI END lines, then the average cost of such a projector will be about 90,000 - 150,000 (again, depending on the characteristics and technology used). The price information presented is quite arbitrary; the price largely depends on the manufacturer, functions, design and capabilities of the device.

Projectors have changed a lot since they hit the consumer market. These are no longer those expensive devices with equally expensive maintenance that could only be used in the dark. Today, a projector allows you to view photos and videos and can easily replace a TV or personal computer screen. And the price of models supporting Full HD resolution is equal to the cost of 40-inch television receivers. It's time to take advantage of this technology and become the proud owner of a home theater with a truly gigantic screen with a 300-inch diagonal, which is approximately

Image

The main parameter for choosing a projector is image quality. But how can this be done if the much-needed assessment of several models of an expensive device cannot be carried out due to the lack of a viewing room?

You can evaluate the image quality of projectors using the following parameters:

• imaging technology;
• matrix size and resolution;
• contrast;
• brightness;
• focal length.

First of all, image quality depends on projection technology. Three technologies are currently used: DLP, LCD and LCOS.

DLP

DLP (Digital Light Processing) uses a matrix of angle-changing micromirrors that direct light into focusing lenses. The coloring of a beam of light occurs in different ways. Some manufacturers use a rapidly rotating three-color wheel. This causes the eye to see alternating monochromatic images, which may affect some people, and also creates a rainbow effect that interferes with viewing. Others use three micromirror arrays for each color separately (3DLP technology). Projectors using 3DLP technology are among the best but also the most expensive projectors.

LCD

LCD (Liquid Crystal Display) technology uses three liquid crystal matrices to form the red, green and blue components of the video signal. The flow of light passing through a prism or a sequence of dichroic filters, transmitting one part of the spectrum and reflecting the other, is divided into three components. Each is directed through its own LCD matrix, which, by changing the flow of light passing through each pixel, creates a single-color image. The combination of the three components produces a multi-color projection. Among the disadvantages of this technology is the low image contrast (due to the fact that the crystal transmits light when closed, and the matrix throughput does not exceed 7%).

LCOS

LCOS (Liquid Crystal on Silicon) is based on the previous two. But light does not pass through the liquid crystal matrix, but is reflected by the liquid crystals on the silicone. This results in high-quality images without the disadvantages of DLP and LCD technologies. In addition, it becomes possible to increase the pixel density and achieve high image resolution. But the price of LCOS projectors is quite high, which so far limits their use to cinemas and large presentation halls.

LED

LED technology (English Light-Emitting Diode, light-emitting diode) uses one of the above technologies to create an image, with the difference that the light source here is an LED matrix. This eliminates the need to replace lamps and reduces energy consumption. The guaranteed service life is 25 thousand hours. The disadvantage is the low luminous flux, not exceeding 2000 lumens.

The laser projector is equipped with a group of laser diodes of primary colors. Less expensive are hybrid laser-LED projectors, which combine a blue diode laser, a green fluorescent element and

Permission

Resolution is determined by the number of pixels. For a high-quality image, these parameters of the video projector and source must match. You can play a signal with a different resolution, but the image will be distorted by compression algorithms.

Popular resolutions are 1280 x 768 WXGA, 1280 x 720 HD, 1920 x 1080 Full HD, 1920 x 1200 WUXGA.

Brightness

Luminous flux is measured in lumens. Projectors with a brightness of 2000-3000 lumens are used in classrooms and small conference rooms. A luminous flux of 3000-4500 lumens is suitable for large conference halls. The brightness of the image in this case is sufficient not to darken the room. Ultra-bright projectors over 4,500 lumens are used in concerts, nightclubs, churches, etc. The cheapest and smallest portable projectors with lumens less than 2,000 require full or partial darkening of the room.

Contrast

The ratio of the highest and lowest illumination of the screen is called the projector contrast. For example, a contrast ratio of 10,000:1 means that the brightness of white is 10,000 times brighter than black. In an undarkened room, contrast is leveled out by external light sources and is inferior in importance to the luminous flux of the projector.

Lens

Video projectors can be equipped with lenses that can be manually or automatically changed. This is necessary to change the image size without moving the projector itself.

The lens is also characterized by the ratio of the distance to the screen to its size. Projectors come in long throw (2-8:1), standard (1-2) and short throw (less than 1).

Features of LED projectors

• Indoor use requires dimming for maximum image clarity and brightness.
• Devices with a luminous flux of up to 300 lumens are designed for a screen width of 0.2 m, and more than 500 lumens - up to 3 m.
• Suitable for mobile home cinema. They are not a full replacement for projectors with metal halide lamps.
• Portability is achieved by the presence of an external power supply and wireless connection.
• Models with high luminous flux have a high noise level, so they are suitable for use in public places.
• Energy consumption is minimal.

LED projector: review of popular models

Every day new models of projectors appear on the market, the light source of which is LEDs. Only those LED projectors whose reviews were positive are discussed below. So, let's begin.

The ViewSonic PLED-W800 mini LED projector is a pocket device designed for business presentations, as they say, “on the go.” But, according to consumers, the power of the luminous flux allows it to be used at home.

California-based ViewSonic has been specializing in projection equipment since the late 80s. And a few years ago she pioneered a new line of mini-LED projectors with the PLED-W500 model. The W200, W600 and W800 models are currently being produced.

The numbers in the model name correspond to the luminous flux power in lumens. On paper, a comparison with the power of metal halide lamps, which exceeds 2000 lumens, does not speak in favor of an LED projector, but in practice, judging by customer reviews, the device illuminates the screen brighter than expected. The portable device is capable of delivering PowerPoint presentations, delivering an 80-inch HD 1280 x 720 image at a distance of 2.5 m with brightness that does not require darkening the room. However, to watch movies, you will need to close the curtains and turn on the Movie mode, which will give the image a more natural color. The compactness of the device required sacrificing a change in focal length. But there is a mount for mounting on a tripod. If the projector is tilted relative to the screen, the image will be automatically adjusted.

The ViewSonic Pro9000 is a hybrid laser-LED projector that is ideal for home theater use. Beautiful colors provided by the DarkChip3 chip, high Full HD image clarity, 16,000 lumens of light output and a contrast of 100,000:1 - this is what the consumer especially likes. The projector design does not use lamps or filters, which reduces the cost of operating the device to almost zero.

LG PH550, PW1000, PW1500 - LED projectors for home, introduced in January 2016. Luminous output and resolution (H for 1280 x 720 and W for 1280 x 800) are indicated in the device name. The PH550 model is equipped with a battery designed for 2.5 hours of battery life, Bluetooth sound, and wireless communication with Android OS devices. The PW1000 is also equipped with a digital TV tuner and is 3D compatible, while the PW1500's brightness speaks volumes.

Vivitek Qumi Q5 is a portable mini-LED projector with 1600 x 1200 resolution, 500 lumens brightness and 3D support. The screen size is 30-90 inches (0.76-2.3 m) at a distance of 1-3 m. There is also a built-in player, 4 GB memory, USB port, wireless connection, Internet browser and battery. Users note excellent color reproduction, contrast, image quality, design and compactness, but some are unhappy with the fan noise and insufficient volume of the device.

The Qumi line also includes LED projectors Q4, Q6, Q7 Lite, Q7 Plus. As the number increases, so does the brightness, which in the latest model reaches 1000 lumens. The contrast is 30,000:1, the resolution is 1280 x 800. The projector can be controlled using mobile devices running Android or iOS. There is trapezoid correction, lens shifts in the horizontal and vertical directions, and optical zoom.

Vivitek Qumi projectors are manufactured by the Taiwanese corporation Delta Electronics.

Optoma Products

Optoma offers the following projectors with LED technology.

ML750e is a compact and lightweight (less than 400 g) device. This is a portable LED projector designed for gaming, watching movies and presentations without using a PC; There is built-in memory and a slot for connecting a micro SD card. Resolution 1280 x 800, contrast 15,000:1, screen size 17-100 inches, projection distance 0.5-3.2 m. Consumes 65 W in operating mode and 0.5 W in standby mode. Users are very pleased with the ultra-mobility and multifunctionality.

The ML1500e comes with a built-in media player, document viewers, stereo sound, wireless connectivity and a memory card. Resolution 1280 x 800, contrast 20,000:1, screen size 17-100 inches, projection distance 0.5-3 m. Consumes 145 W.

HD91+ - second generation LEDs are used, Full 3D 1080 p image, optical zoom. Contrast 600,000:1, screen size 30-300 inches, projection distance 1.5-19 m. Consumes 245 W in bright mode and 150 W in movie mode. There are no complaints from users.

Optoma, a global corporation with headquarters in the United States, Europe and Asia, manufactures projection and audio products for business, education and home use. Founded in 2002 in Shanghai, China.

Projectors from BenQ

BenQ produces portable LED projectors GP30, GP3, GP20.

GP30 is a short-throw (40-inch screen at a distance of 1 m) LED multimedia projector with a luminous flux of 900 lumens. According to the manufacturer, it is distinguished by the presence of stereo sound with SRS HD, support for MHL and WiDi wireless content transmission technology. Models GP3 and GP20 have brightness of 300 and 700 lumens, respectively. 1280 x 800 resolution, 100,000:1 contrast, +/-40° tilt correction. In 2014, the Taiwanese company BenQ became the world leader in sales of high-definition projectors, and the total number of models sold exceeded 1 million.

NEC NP-L102W is a 1000-lumen LED projector with 1 GB of internal memory and a slot for SD cards up to 32 GB, which allows you to leave your laptop at home and conduct presentations from a flash drive. The built-in office viewer allows you to open MS Office files and PDF documents. The design does not use rotating filters, which, according to reviews, reduces noise and eliminates the need for maintenance. Resolution 1280 x 800, contrast 10,000:1. The Japanese company NEC Display Solutions, the manufacturer of this projector, has been in business for more than 20 years.

Panasonic

In the Panasonic PT-RZ470U professional projector, the lamp is replaced by an LED laser system with a luminous flux of 3500 lumens. Resolution 1920 x 1200, contrast 20,000:1, screen size 40-300 inches, distance to the screen - 2.6-10 m. The hybrid light source, according to user reviews, has higher color purity, and the Digital Link system will allow HDMI transmission , uncompressed HD video, audio and commands over a single Cat5 cable over distances of up to 100 m. Panasonic pioneered the projector industry with its production in 1975. And it continues to occupy a leading position to this day, holding a record for projector brightness of 9000 lumens and being the first to introduce wireless technology into devices of this type. Users are very pleased with the overall image quality of the new type of projector, but the level of contrast and color reproduction, according to them, is still at an average level.

New products from Casio

The Japanese company Casio, which was the first to produce hybrid laser-LED LED projectors, offers affordable models XJ-V110W, XJ-V10X, XJ-V110W, XJ-F210WN, XJ-F100W, XJ-F20XN, XJ-F10X, the brightness of which reaches 3500 lumens. The contrast of the new projectors is 20,000:1, tilt correction, wired or wireless network connection.

Acer

Acer also produces portable LED projectors K137i, K138ST, K335 with a resolution of 1280 x 800 pixels and a luminous flux of 700, 800 and 1000 lumens, respectively. Contrast 10,000:1, screen size 17-100/25-100/30-100 inches, screen distance 0.6-3.2/0.4-1.7/0.9-3.0 m, tilt correction + /-40°, support for PDF, MS Office formats, power consumption 75/80/135 W. Owner reviews are mostly positive.

Chinese lanterns

It is impossible not to mention here that the market is flooded with cheap

Light Emitted Diodes (LED) are actively penetrating our lives. Consuming relatively little energy and possessing significant durability, step by step they are replacing traditional incandescent lamps in household lighting fixtures, eloquently announcing themselves as an excellent alternative to fluorescent backlighting in LCD displays, and, finally, are ready to lead the revolution in the country. video projectors. LED video projectors, their features and the current state of affairs on the market will be discussed in this material.

Disadvantages of Traditional Projectors

Modern video projectors, for all their positive qualities, also have the following disadvantages:
1) the projection lamp has a limited service life, high cost and significant energy consumption;
2) the projection lamp gets very hot during operation - each projector needs a special cooling system, which not only consumes additional energy, but also makes noticeable noise (due to the rotation of the fan);
3) the presence of a projection lamp and cooling system imposes certain restrictions on the size and weight of the projector.

LEDs to the rescue

LEDs “started their career” as household lighting devices, then found application in the automotive industry, then LEDs began to be used to backlight LCD matrices in the corresponding video panels, and finally made their way to video projectors. The idea of ​​replacing a traditional incandescent projection lamp with an LED analogue, at first glance, is simple and obvious. However, the creators of the first LED projectors had to solve a number of fundamental technical problems. First, choose the most appropriate image formation method for LED specifications. The use of LEDs in conjunction with LCD matrices (which are equipped with most projectors sold in the world) turned out to be futile. After all, working with LCD matrices in transmission mode implies a significant (up to 60%) weakening of the light flux on the way from its source to the lens. Therefore, micromirror DMD chips used in DLP projectors are most suitable for symbiosis with LEDs. It is no coincidence that Texas Instrument (the founder of DLP technology) was one of the first to propose using their matrices in conjunction with LED backlighting.

However, currently there is a concept of using LEDs in conjunction with LCoS matrices (they also work on the principle of light reflection) - it is quite possible that LEDs will lead to a “renaissance” of this technology.

It is worth emphasizing that LED projectors owe their appearance to significant progress in the technology of producing bright LEDs. Lumileds is currently the leader in this field and the main LED supplier for the projection industry. Today, its specialists are intensively working to create even more advanced LEDs, the characteristics of which (brightness, energy efficiency) are becoming better with each new generation.

Operating principle of an LED projector

So, in an LED projector, instead of a “hot” and energy-hungry incandescent lamp, LED light emitters are used. There are either three of them (red, blue and green) or more (in addition to the primary colors, Lumileds proposed adding blue and yellow in order to increase the luminous flux and enrich color rendition). LED projectors also do not have a light wheel (which is traditionally used in DLP devices). Instead, a special electrical circuit is responsible for the formation of each color layer of the image, which switches the backlight color channels with a certain (imperceptible to the eye) frequency. Thanks to the inertia of visual perception, we see a complete picture on the screen.

LED projectors: a lot of advantages

1) Dimensions and weight
The LED+DLP image forming method allows all electronic elements to be placed as closely as possible to each other and create miniature (about the size of a CD box) and subminiature (about the size of a mobile phone) projectors.

2) Power consumption
LEDs consume 10 times less energy (LED - about 10 W, lamp - about 100 W). This means that LED projectors can be powered by rechargeable batteries.

3) Service life
The service life of a typical projection lamp is on average 2–3 thousand hours. For LED solutions, this figure is about 20 thousand hours without a drop in brightness. There has been a tendency to increase the above-mentioned resource to 100 thousand hours.

Projection technologies are gaining more and more fans in the market of modern technical innovations. And even in this area there are already two main competitors: DLP and LCD projectors. What is the difference between DLP and LSD projector technology and which unit is better to purchase? Details in this article.

Projection technologies

Bypassing the most popular LSD and DLP technologies, it is worth remembering other amazing units that use CRT projection. The ancestors of currently competing technologies showed high image quality back at the end of the 20th century, when color television had just entered the lives of modern people. Its followers, DLP and LSD technologies, have long been in conflict with each other, because each of them strives to gain popularity and has its own specific features.

LSD or Liquid Crystal Display is based on combining mirrors and reflecting light from a special lamp, while DLP or Digital Light Processing goes the other way, using a matrix of microscopic mirrors.

What is it and how does it work in practice?

Features of DLP technology

What is DLP? DLP technology was invented by Texas Instruments, a company that was able to create a lightweight projector model weighing up to three kilograms. At the same time, the power of these units has not gone away - more than 100 ANSI Lm - a rather serious indicator. This technology was first introduced at the end of the 20th century and was a digital device with a large number of mirror surfaces, in which manufacturers abandoned bending mirrors and moved to a matrix of rigid mirrors that have only 2 positions.

DLP technology made it possible to make an image colored using color and light manipulations. All these mirrors are made of a special, highly reflective aluminum alloy. On the opposite side of the corners of the mirrors are electrodes that are attached to the RAM memory. After supplying electricity, these mirrors take one of two possible positions, differing by 20 degrees.

Then the light flux that enters is reflected from the mirrors and supplied to the lens, where a very effective light absorber is located. It ensures minimal reflection of unnecessary light and reliably removes excess heat, so the DLP module never gets hot.

Several thousand small mirrors are attached to the matrix so close to each other that the image appears very smooth and crystal clear to the viewer. Already in 1995, mass sales of such DMD chips began.

Important! This technology allows you to submit 60 or more frames per second, and the resolution that is available with a DLP system is about 16 million colors.

In addition, the crystals on the matrix are so small that they can easily fit a handful in the palm of your hand. The distance between them on the matrix is ​​no higher than 1 micron, and the crystal surface area itself is less than 16 microns, which is very impressive.

So, the picture is projected, however, where do these 16 million colors come from, since there are only thousands of mirrors on the matrix that only reflect? Here the creator of the DLP projector turned out to be a real magician. A color image is obtained by quickly and sequentially moving light filters!

Operating principle of a DLP projector

Now, in the footsteps of Texas Instruments, many companies and enterprises are producing cinema using the DLP system.

For example:

• ACER;
• PROXIMA;
• OPTOMA CORP.;
• VIEWSONIC;
• SHARP;
• KODAK;
• TOSHIBA;
• COMPAQ et al.

Based on their operating principle, such projectors are divided into several groups:

• Single matrix projectors. The main principle of operation in such a DLP projector is light filters rotating between the matrix and the light source - blue, green and red. The rotation speed of this filter determines the rapid change of frames and the formation of a full-color image, which is formed in turn by each of the listed colors. Such portable projectors weighing up to 8 kg are all single-matrix.
• Three matrix projector. In it, the light stream is divided into three color beams, each of which is reflected from three matrices. The rotation speed of the filter disk is not limited here, so this projector has purer color and smoother frame changes. This varied reflection is brought together with the help of a prism.
• Dual matrix projector. This unit has two light outputs, in which red light is reflected from one matrix, and blue and green from the other. The light filter is like a separator: alternately separating either the green or blue component from the spectrum. This projector is something between the first and second types in terms of quality and frame rate.

Features of LSD technology

This type of projector uses a different lamp method in which white light is sent to a combination of mirrors. These flexible mirrors divide it into 3 color fractions: red, green and blue. For each color, LSD technology has its own matrix, so very often this technology is called 3LSD. After dividing into colors from the spectrum, with the help of a prism, all the colors are combined into an image, which also has several million colors.

Note! Using such matrices, a special dichronic image is obtained, which, when absorbing only one-third of the spectrum from white light (three colors are used), transmits the remaining two-thirds of the spectrum and creates additional colors.

Instead of aluminum mirrors, the LSD matrix uses pixels, which make up the reflective surface. The LSD matrix, a technology that works not on reflection, like DLP, but on transmission, separates excess light a little worse than the special chip in the first technology, so this image will have less contrast.

This has significant advantages:

• The matrices do not move, which means they can be in a half-closed position just at the moment when brighter colors in the picture are needed.
• Without switching back and forth, the 3LSD projector matrices wear out less, which significantly increases their service life.

3LSD or DLP? Today, the 3LSD marking denotes not only three matrices in the projector, but also improved technology, which increases image contrast every year. This is why 3LSD projectors or LSD x3 remain afloat and are included in the sufficient High-End segment for home theaters.

Comparative characteristics of DLP or LCD projectors

Despite the fact that with the advent of DLP technologies, LSD projectors were partially forced out of the market by a new type of image projection, this does not mean that DLP has more disadvantages than advantages. To objectively consider the features of both technologies, it is best to analyze the characteristics and compare the data of projection devices. So, LSD or DLP?

DLP projectors:

• Pros - These projectors produce images through reflection, so the light output will be more powerful and full, resulting in a smooth and crystal clear image. Since the image speed is 1000 times higher than that of LSD, DLP technology produces smoother frame switching. The image does not shake. The weight of these projectors is much less than that of competitors. The pixels on the screen are virtually invisible, and the design without more filters ensures zero maintenance, which also saves the user money. Due to its extended service life and savings in maintenance, this projector pays for itself quickly enough, which immediately reduces the total cost of ownership.
• Cons: This projector requires a well-lit room. The projection of the image can be longer than that of LSD, due to which the image may appear slightly deeper when viewed on the screen. Sometimes there is a “rainbow effect”, since the filters rotate clockwise and in more budget models can distort colors. In addition, rotating filters produce some operating noise.

LSD projectors:

• Pros: Three primary colors provide higher image brightness and contrast. In such projectors, the installation possibilities are almost unlimited due to the wide range of lens optics. Since the filters do not rotate like DLP projectors, you will barely hear your LSD device operating. In well-lit rooms, this projector produces richer colors than its main competitor. And in addition to the above advantages of LSD projectors, they allow their owner to save significantly: they consume very little energy, since they produce much less heat than DLP units. And of course, you will never see a distorted image and a “rainbow effect” due to different matrices.
• Cons: The filter of LSD projectors needs to be constantly cleaned and changed occasionally. The pixels in such an image are more noticeable, and the projectors themselves are much more massive and heavier than portable DLP devices. Sometimes, due to their lower contrast, such projectors can turn black tones into gray. And perhaps the most significant drawback is the complete disintegration of colors after very long use.

LCoS technology

Interestingly, there is also a kind of symbiosis of these two technologies, presented in more expensive projector models. What is this?

LCoS technology is a new hybrid of LSD and DLP technologies, a sort of “reflective 3LSD”, as experts call it. It literally translates as “liquid crystals on silicon.” Moreover, in essence, this is just an LSD matrix, which is glued to the mirror surface of the DLP. Thus, the light flux passes through the LSD matrix twice, cutting off excess light and thereby increasing contrast.

For the user there will be no “rainbow effects”, no gap between pixel elements - that is, this sensational “mosquito net” principle, which many budget LSD screens suffer from. It turns out that the third, so far “shadow” competitor for both technologies will be LCoS - a video projector, which is still in development.

Experts note that these projectors will become quite expensive, as they will combine the advantages of both technologies. However, this is not without its drawbacks: in addition to the high price for the unit itself, you will have to pay a tidy sum for the maintenance of your device, since it will use three-matrix projectors with several filters, as well as ultra-sensitive matrices, which are also subject to rapid wear.

In addition, another technology of the future should be mentioned - this is LDT - Laser Display Technology, which, as you might guess, uses projection technology using a laser beam. The image of such a projector will be ideal even when the area is 100 square meters. Such projectors are produced at very exorbitant prices - no less than $200,000, but manufacturers promise to bring such technologies closer to the lives of ordinary people in the near future.

Conclusion

Both DLP or LSD technologies, as well as their symbiosis LCoS technology, have both their key advantages and undeniable disadvantages. And it is important to choose exactly the projector with the right technology that will meet all your needs. For example, Digital Light Processing or DLP technology is more suitable for mobile presentations, since projectors with this type of projection are very compact and lightweight. They are easy to carry and easy to connect.

Such projectors have become regulars in home theaters among film lovers around the world, because a DLP home theater projector provides a more stable image and better contrast. Moreover, it is much more pleasant to watch a film with a smooth image of the picture, and not with an image broken into pixels. On the other hand, LSD or Liquid Crystal Display has more capabilities for accurate color reproduction.

In addition, many users claim that if you plan to first film a presentation and then demonstrate it on the screen, then you won’t find a better LSD projector, because it will provide a clearer image. Errors and creeping lines will not be visible, and diagrams, graphs and texts will be transmitted clearly, without blur.

Thus, choosing the best technology in projectors is impossible. We compare their characteristics, and each of them has its own number of advantages and disadvantages.