Back projection ( DLP ) ( PDP ), plasma, LCD screen ( LCD ) have been launched, provides people with contrasting selection space. There is no doubt, larger, thinner, more advanced technology development direction, for the curtain wall ( TV wall ), also from the traditional CRT to display, plasma, LCD development. Then, rear projection, plasma and LCD that a more technical advantages, can meet various application needs? We believe that the LCD will be better able to meet the application requirements. We will list the projector, plasma and LCD three shows the technical principle, and analyzes on several key indicators on their respective advantages and disadvantages.

A brief analysis of the principle of LCD

Liquid crystal is the use of liquid crystals in the effects of voltage deflection theory. Due to the composition of the liquid crystal screen at the same point can display red, green, blue three colors, or a point of liquid crystal is composed of three point up, which according to a certain order, through voltage stimulation of these liquid crystals, can present different colors, different proportion of collocation can show the myriads of changes color. Liquid crystal itself is not luminous, it relies on the backlight tube to emit light, so the LCD screen backlight tube depends on. Since the liquid crystal with point imaging of reason, so the screen which constitute the more points, more fine imaging effect, vertical and horizontal points constitute the resolution of LCD TV, the higher the resolution, the better.

Advantages: high resolution, thin thickness, light weight, low power consumption, long life, no radiation.

Disadvantages: seam is slightly big.

A brief analysis of the principle of PDP

PDP is a use of the gas discharge display technology, the working principle and the fluorescent lamp is similar to. It uses a plasma tube as a light-emitting element, a plasma tube screen each corresponding to a pixel screen, with glass as substrate, the substrate is spaced at a distance, forming a discharge space. The discharge space filled with neon, xenon, a mixture of inert gases as the working medium, in the two block of glass substrate on the medial surface is coated with a conductive metal oxide thin film as the excitation electrode. When added to the electrode voltage, discharge within the space of mixed gas discharge plasma phenomena have occurred, also known as plasma effect. Discharge produced plasma UV, UV excited coated with red green blue phosphor screen, the screen emits visible light, showing images. Advantages: bright color, high brightness, high contrast defects: power and calorific capacity is very big, the phenomenon of serious burns, quality decrease with time.

A brief analysis of the principle of DLP

Rear projection principle is very simple, inside the device provided a projector, a lens magnification image is projected onto a screen on the back, is a rear projection. It is based on this principle the birth of the projection, due to different types of the projector, can be divided into CRT ( cathode ray tube ), LCD ( LCD ), DLP ( digital light processing ) and several. CRT rear projection to camp in the low-end products, and several other projection corresponding to high-end products, among which the most outstanding DLP projector, the image sharpness, brightness, color, visual angle and volume, than the traditional CRT rear projection has been greatly improved. Below the rear projection to refer to the DLP rear projection.

Advantages: the cheaper end display scheme.

Disadvantages: the volume and the weight is too large, long time of uninterrupted work, accelerate the backlight lamp aging.

Liquid crystal ( LCD ) and plasma ( PDP ) display technology

The current mainstream technology of flat panel display including liquid crystal display technology and PDP plasma display technology. Below, we will from several aspects to compare the two kinds of display technology.

1 life

Large screen display because of its high cost, so that the service life is becoming the primary problem, in theory the LCD and plasma display life can reach 60000 hours, but due to the two display luminescence principle is different, the practical application of difference. A plasma display panel in which each pixel unit is actually a miniature bulb, due to the use of the incandescent light bulb, the image quality will be deteriorated over time, although the current technology to the current technology can make the plasma display working time to 60000 hours, but may be of use to 20000 hours will malfunction causes the display backlight, the decline in the quality of half. And plasma if long play a fixed image on the screen, leaving a shallow traces (GTG ) is" burn-in", for example, if a signal is too long, the corner of the screen may be imprinted logo on the screen, in the view of other signals can still see the afterimage. Typically, a continuous watch 10 ~ 20 hours can cause visual afterimage, up to now the problem is not the perfect solution. As a result of liquid crystal TV work is different ( using liquid crystal in voltage aequorin imaging principle. Composition of liquid crystal screen has three kinds: red, green, and blue three primary colors, which according to a certain order, through voltage stimulation of these liquid crystals, can present different colors, different proportion of collocation can show the myriads of changes color ), liquid crystal display there is generally no ghost and image quality degradation problem.

The 2 resolution

The display screen is used to output high definition image and video, so the definition is very important, for the display technology, inspects the definition level, a critical look at the resolution size. At present, for large screen liquid crystal physical resolution up to 2024 x 1080, and big screen plasma resolution still remain in the 853 x 480, and for single screen display, LCD screen is obviously better than the plasma LCD screen, at the same time to overcome the plasma screen in a low gray condition the flicker problem, so from the perspective of resolution and clarity, plasma chamber 's LCD a domain.

3 environmental safety

The plasma display panel is flat design, but also on the screen glass is very thin, so it can not bear the weight of the surface of the accident, prone to problems such as liquid crystal display screen burst, because of the different materials, so it does not appear that this problem. In addition to tell from environmental protection angle, plasma screen fluorescent powder on the emitted ultraviolet absorption rate of less than 20%, 80% into radiation, long time use for the user of the health influence. LCD screen because of its light principle of different radiation close to zero, so that users without any menace from the "rear".

4 power consumption

Power consumption size is a matter of common concern, plasma power consumption big, summer even as oven that has always been very popular. New technology application although to some extent to reduce the power consumption, heat, but also can prolong the service life, but did not fundamentally solve the problem, Panasonic and sharp in this issue had a confrontation, sharp had 37 Inch LCD screen with 37 Inch plasma displays were compared, the results of LCD TV power consumption is not 200W, and plasma TV is about 300W. The liquid crystal at work when the screen temperature than plasma low many. For light weight, thickness of thin display device, the high energy plasma screen requires cooling condition is very high, if not leave enough space for heat dissipation, easy to cause the screen due to over-high temperature damage. LCD screen does not have this problem.

The 5 luminance

Display image clearly is not clear and there is a certain relation between the brightness, if insufficient brightness, many of the details on a dark, what also can't see. Liquid crystal image depends on the liquid crystal panel on the back of the lamp tube through the liquid crystal plate to form image, earlier, liquid crystal display brightness has been a big problem, improve the brightness in two ways, one is to improve the liquid crystal panel light through rate, but this is limited, the space has not improved. Novel liquid crystal plate has been generally adopted multiple lamp technology, brightness is improved greatly, in the same parameter, LCD brightness effect is slightly better.

6 visual angles

Since the liquid crystal back light, the light from each pixel of the gap through a gap, limiting the light radiation direction, when we watch when there will be limiting angle, known as visual angle. While the plasma is each pixel of a direct light, this is not a problem. But with the development of LCD technology, can now view generally exceeded 170 degrees, the highest reached 176 degrees, the basic can all watch, can be said to be roughly the same two.

7 cost

With the development of technology, the LCD screen in the lower cost, LCD price superior days are gone for ever, now in the same display under conditions of large screen LCD cost is lower than the big screen plasma, can be said that the LCD screen of the cost advantage undoubtedly.

The above list of LCD and plasma screens comparison, we believe that, under the same conditions, large screen LCD performance than the big screen plasma can be obvious, liquid crystal display technology has more advantages, and along with the development and popularization of big screen liquid crystal, liquid crystal display technical advantages will be further show.

The large screen splicing wall has three kinds: DLP projector, plasma displays, LCD display. Now the same size three shows the basic performance indicators for comparison

Performance index

Liquid crystal

Rear projection

Plasma

Brightness

LCD 500-800 lumen

Rear projection 300-500 lumen

Plasma 600-1000 lumen

Contrast

Liquid crystal 1000: 1-1500: 1

Projection 300: 1-500: 1

Plasma 3000: 1

Analysis.

Brightness and contrast is the key index of display device. Plasma two high value, because the calculation method is not the same as. If you use the American Standard ANSI is calculated, with the same picture black and white for comparison, the same parameter of plasma and LCD

Color saturation

LCD 92% (DID screen )

Rear lower

Plasma 93%

Analysis.

The higher color saturation, displayed image is more gorgeous.

Resolution

Liquid crystal 1366x768 ( 46 inch )

Rear projection 1024x768 ( 42 inch )

Plasma 852x480 ( 42 inch )

Analysis.

The resolution decided to screen clarity, liquid crystal display resolution is relatively high, the picture is more delicate, can show more.

Power waste

Liquid crystal 200W ( 46 inch )

Rear projection 300-500W ( 50 inch )

Plasma 500W ( 42 inch )

Analysis.

Liquid crystal of high luminous efficiency, power consumption is relatively low.

Life

LCD 50000 hours ( backlight )

Rear projection 5000-10000 hours ( bulb )

Plasma 5000-10000 hours ( screen )

Analysis.

LCD and projection of life are only associated with the light emitting component, use after the expiration of the backlight lamp bulb can be replaced or changed. But the life of plasma associated with the screen, use the expiration can only be scrapped, unable to repair.

Burn

LCD: doesn't burn

Rear: basic will not burn

Plasma: burn severity

Analysis.

Burns is seen when the still image stay in one position for an extended period of time, will leave the shadow on the screen. Liquid crystal projection display principle of the screen will not burn, but plasma burn phenomenon is quite serious, which is composed entirely of gas plasma luminescence principle.

Volume

LCD: thin

Rear: larger

Plasma: frivolous

Analysis.

Plasma and LCD belong to the flat panel display, small thickness.

Seam

LCD:

Rear: smaller

Plasma: smaller

Analysis.

LCD backlight part of the screen side LED LCD has a certain gap, the use of LED backlight, LCD rear projection, a seam and plasma.

Summary

LCD screen ( LCD ) in flat panel display technology in one branch alone beautiful, its thin thickness, light weight, low power consumption, long life, without the advantages of radiation as well as the key performance indicators of good performance, it has become the mainstream of development, prospects; plasma due to power consumption and calorific capacity is very big, and there are serious burn phenomenon, not suitable for long time display static monitoring picture, and is used for splicing, the temperature rises higher, resulting in equipment is easy to burn; projection technology volume and weight is too large, the key technical indicators are far less plasma and LCD screen, and a long time to work uninterrupted, accelerate the backlight lamp aging, due to only a few thousand hours life, if operate twenty-four hours a day, a few months they need to replace the backlight lamp.

The information above is from Shenzhen LCM, LCD, LCD screen, LCD display module manufacturers -- Xingyuhe electronic collection.