LED display module design and realization

LED display module design and realization

With the development of socio-economic development and the information age, advertising media company is now widening the field of application of the led screen, called are everywhere. Look at mysterious color display, we doubt it plays software shall have those characteristics and related components.

You can clearly see the LED Flood Light large screen content, require a white backlight. Backlight is present in liquid crystal displays internal optical components, optical-aided by the light source and the necessary components. LED backlight if through such means as increased contrast, zone control, performance is far superior to CCFL back light source. At present, the LED backlighting has been popular in the small and medium size panel, such as mobile phones, digital photo frames and so on, with the development of LED technology and LED chip continues to mature, LED LCD TVs are likely to gradually replace the traditional CCFL LCD TV.

Backlight depending on the location of the light source is divided into lower-back light and side light type backlight. Under direct-type backlight, led strip lights source directly beneath the smooth, light emitted by a spatial distance of the light source and diffusion and mixing of diffusion plate, surface light source emitted, under direct-type backlight requires a certain amount of mixed light distance. Side light type backlight module structure of ultra thin design is more advantage, as the “thin air” up, large size thin-side light LED backlight to become the major TV manufacturers and enterprises in the upper reaches of research.

1 structure design

LED full color side light source is the design of ultra thin structure, the entire structure including: LED Spotlight bars, driven, film material, light guide plate, cooling blocks, frames, back on board. Backlight white LED light, structural design to the entire Active Area of the center point for all parts of the design center, to LCD TV with LCD screen size for the sake of design in other dimensions. Comprehensive consideration of circuit design and optical design of the requirements, to design the structure. Structure design from the u figure OUT layout ⅳ, expressed as a whole body and the relationships among the various components of the Assembly, and then proceeds to part structure design. Framework on the use of segmented design, on the length of segment, avoiding the length is too long. Lights, outlet port settings at the four corners of the back panel, winding length reduction.

2 optical design

Backlight function is by diffuse point source of light making it a surface light source. In order to be eligible for surface light source, first select the appropriate LED, this design is used in the double chip white LED. Through preset white photometric indices, on the LCD screen, optical film, and other related factors analysis of through the back on the calculation of the required luminous flux of the light source. According to the calculations of luminous flux, combined with the LED optical properties of number of the calculates the required LED. As shown in table 1 for selected LED electrical and optical.

In order to increase the brightness of the backlight, match for membrane structures: a diffusion sheet + one BEF+ of a DBEF. Where diffusion is to take the role of diffusion material refraction and reflection of light spray, injection of more uniform: light BEF’s role is to gather, make it vertical into the LCD module to improve luminance: DBEF was originally absorbed by traditional absorption-type polarizer using 50% to increase the brightness of light. Lightguide plate dot diameter 0.54~1.55mm. Figure 1 shows the Lightguide plate part of the network map.

3 circuit design

Light source with dual-chip white LED light, led backlight for distribution in four weeks. In order to achieve a better current uniformity, lamp and hybrid, two and more. In order to achieve better heat dissipation, LED lights with aluminum plate processing. Input voltage of 24V the system as a whole, this voltage is provided by external power supply converter.

3.2 design of drive control circuit

Driver IC is a triple peak current-mode PWM controller, through closed-loop controls the output provides high-precision LED current. The chip contains three peak current mode controllers, provide feedback to IC to ensure high efficiency and high precision. Gate drives are optimized on the chip, used to drive the 0.25A source or O.5A sink current logic level FET, each output current can be linear or PWM dimming for a separate dimmer.
3.3 thermal design

Because the LED luminous efficiency is low, will produce a lot of heat while you work, without addressing the thermal problem, will led to attenuation and shortening of service life of LED light brightness. In order to curb the heat impact of LED backlight luminance and chrominance, thermal design of the LED.

Dear all friends and vistors:

We are a top ranked led display manufacturer with more than 6 years' experience.

We have a industry park with over 30000sqm and 300 employees. Our headoffice are based in shenzhen, China.

Our full color led display are widely used in advertisment, events, concerts, etc.

Our products are sold to over 130 countries and enjoy  a high reputation, because of our outstanding design, favourable price and professional and reliable pre- and after- sales service.

Please feel free to contact me for any further information.

Ryan Yi
Sales Director
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