LED display come from?
As early as 1923, Rosoff (Lossen.ow) in semiconductor research SIC impurities from time to time in light of the PN junction fired, out of the light-emitting diode (LED: Light Emitting Diode) has not been great importance. With the rapid development of the electronics industry, particularly in the 60's, display technology has been more rapid development, people come up with laser shows PDP plasma display panel, LCD liquid crystal displays, light emitting diodes (LED), electrochromic display ECD, electricity EPID Beach show, and so on a variety of new display technologies. As the semiconductor production process and gradually mature and perfect, light-emitting diodes have become more solid in the dominant display.
LED was widespread and rapid development of great importance because it has many advantages. For example: high-brightness, low voltage and power consumption in small, easy-to-integrated, easy-driven, long life, impact resistance and performance stability, and its market prospect is extremely broad. At present, LED has been developed to a high brightness and high resistance to climate and the density of luminous, light-emitting uniformity, and full color.
In the early 1980s, along with the development of the computer, CGA shows that come out of the way, it has 320 * 200 resolution of the four colors in such a short span of 10 years has gone through a display CGA, EGA, SEGA, VGA, SVGA, To the development of ultra-high resolution, precision display from the development of the 320 * 200 * 1600 to 1250, from four 32-bit color to true color, scanning frequency from the development of 15.7K to 150K. The display works by receiving signals from the host reduced to light in the form of display, with the need to develop a large-screen equipment, so it appears similar to the type of projector display devices. However, the brightness of its own reasons not to use high-intensity environment, then emerged again LED display (screen), LED display with large viewing angle, high brightness, colorful and so on. With the development of science and technology, LED display has a wide range of applications, such as stadiums, highways, shopping malls, outdoor advertising, and other places are then applied to the LED display.
According to the survey, people accept the message, 2 / 3 of the information obtained through the eyes. Display technology is also used in industrial production, military, medical, aerospace and even the public security system, such as the cause of the national economy, social life and in the military field, and play an important role in display technology has become a modern human society is an essential life Technology.
Development of LED display
In 1970 the first GaP, GaAsP same knot red, yellow and green light-emitting low-efficiency LED lights have been used in the beginning, digital display and text. Since then entered the multi-LED applications, including aerospace, aircraft, automotive, industrial applications, communications, consumer products, across all sectors of the national economy and tens of thousands of households. As of 1996, LED worldwide sales have reached as much as several billion dollars. Despite years of LED industry in both color and light-emitting efficiency, but because of GaP and GaAsP LED has a long life, high reliability, small current, with TTL, CMOS digital circuits and many other advantages of compatible due to have suffered a lot from the users Green's blind. In particular, in recent decades, high-brightness, of full color LED has been the materials and devices for cutting-edge technology research topics.
Ultra-high brightness (UHB) is the luminous intensity of 100mcd meet or exceed the LED, also known as the candela (cd) level LED. A1GaInP high-brightness InGaN LED and development have progressed very rapidly and has now reached conventional materials such as GaA1As, GaAsP, GaP can not reach the level of performance. Toshiba Japan in 1991 and the United States for the development of HP's InGaA1P 620nm orange ultra-high brightness LED, 1992 years InGaA1p590nm yellow ultra-high brightness LED-based utility. In the same year, Toshiba developed InGaA1P 573nm yellow-green ultra-high brightness LED, to light up to law 2cd. Japan in 1994 Nichia Corporation for the development of blue InGaN 450nm (green) color super-high brightness LED. At this point, color display required for the three primary colors red, green, blue and orange, yellow multi-color LED's have reached the level of luminous intensity candela, to achieve a super high brightness, full color, LED so that outdoor all - Color display a reality.
China started the development of LED in the 1970s, the property sector in the 1980s. About 100 enterprises, 95% of manufacturers are engaged in post-production package Road, needed to die, almost all imported. Through a number of "Five-Year Plan" of the technical, technological research, the introduction of foreign advanced equipment and some of the key technologies so that our production of LED technology has been a step forward.
LED displays an overview of
LED (Light Emitting Diode light-emitting diode) display is a collection of electronic micro-electronics technology, computer technology, information processing in one large display systems. It is its large screen, powerful visual, flexible display, and other unique advantages, the current international use of a wide range of display systems. Information dissemination is an epoch-making facilities. According to the wavelength of its light-emitting can be broadly divided into visible light LED, infra-red LED. Visible light LED power consumption to long life, low heat, single-color light-emitting, fast reaction rate, the impact resistance of the mechanical properties, such as small size, is different from traditional optical properties of new products, widely used in automotive, communications, new Products, new product information, consumer products, signals and large-scale display of information, and so on. Infra-red LED also has the characteristics of visible light, but not in the wavelength of visible light range, mainly in the application of remote control, wireless communications, optical communications, sensing, automatic control, and so on.
LED Electronic Display System is a brand-new high-tech advertising media notice, since the late 1980s in the Chinese mainland market, with its lower prices and better quality, lower power consumption, can display graphic information in order to display video images, Clear the screen, color-yan, display flexibility, and other functions in all walks of life in the rapid popularization and application. ,
After years of development, LED display development, production technology has become mature, stable, and new product quality has been greatly improved, is a mature product. At present, LED display more kinds of new products. There are: Article screen, graphic monochrome screen, two-color, full-color LED electronic dot-matrix display and digital electronic board. In the above-mentioned new types of products, electronic full-color dot-matrix display is now mainstream products, other types of new products has been more widely used.
LED display the advantages and characteristics of
LED solid-state light-emitting devices belong to, have the following advantages:
◆ long life (more than 100,000 hours), photoelectric conversion efficiency, energy saving.
◆ fast dynamic response (NS-class), to achieve the level of the video display refresh speed, full-screen refresh rate of 72 / s and above.
◆ drive low voltage (DC +5 V), and direct-chip micro-computer interface, no need to design a special interface circuit; computers with green logo;
◆ good program, it is easy to achieve network operations;
◆ be able to achieve in the computer model SVGA (256 gray, 1280 * 1024 resolution), the great convenience of programming, it is essentially a computer display, deputy.
LED video display technology characteristics
(1) a clear picture
According to the human visual characteristics and features LED display, using the Company's non-linear advanced scanning technology (γ correction), so that the display screen at all levels to be a complete reflection of subtle changes in a clear and greatly improve the quality of the images pixel for less The display, the technology is of particular importance.
Nonlinear differential display technology, that is, the difference in the end zone brightness small increase in progression, to gradually increase high-brightness zone difference, the visual effects caused by the "differential consistency", this will have a better visual effects.
(2) good compatibility
SVGA compatible computer models, which can be accessed by a variety of video equipment.
(3) images with a computer screen display, adjustable screen map location, with professional control software.
(4) gray-scale high-technology
LED screen with its high-level gray-scale, detailed pictures in the industry have been well received. In the "LED display detection method" has been a breakthrough technology IOBIT the cutting edge of technology, is to advance the field of higher.
(5) lower noise current technology
LED display driver chips used internationally advanced U.S. TI's 5902 launch of the system in full-color LED display in the field to play the leading role. A combination of the characteristics of its chips, and TI formed a company to study the noise down constant current technology to ensure power supply noise and other factors on the source of power LED display to reduce the impact to a minimum.
(6) to adjust brightness Technology
In order to adapt to different weather conditions, so that the display screen to achieve the best results, LED electronic display specially designed light of the 32 automatic, manual adjustment device. To ensure that the entire LED display in a variety of circumstances to achieve the best results show.
(7) strong convective-hot platoon system
LED display screen work-issued high heat, in order to ensure the stability of the entire display system in the state run, I display on the cooling system, the company conducted a thorough study, taking into account all the flow of air, to come up with a Strong convection thermal emission system, the system more stable and reliable.
8) Media Network
The arrival of the information age, so the company launched a comprehensive media network system solutions, the company LED display system as a network of terminals to form a standardized interface, the standard video signals, audio signals, other network equipment direct access , And compatibility.
(9) improve the distribution system
◆ distribution system with remote control
◆ have a direct function of supply
◆ with over-current, short circuit, and other power protection, automatic processing of a variety of emergency situations.
◆ screen switches automatically from time to time with the functions can be no one left, with more output and power-delay.
◆ intelligent power supply, fans can be automatically opened and closed, over the automatic protection and automatic recovery, the need to safeguard the people.
