JHP series gold-loaded carbon medium temperature non-cyanide desorption and same temperature electrolysis equipment was developed by Changchun Gold Research Institute Co., Ltd. in 1998 and entered the market. It has been used in more than 800 enterprises at home and abroad. This series of equipment is oriented to the gold-loaded carbon in the gold cyanide carbon slurry process for gold desorption and electrolysis, and the gold adsorbed on the gold-loaded carbon is produced in the form of high-grade gold mud. After decades of practical application and continuous optimization and improvement in enterprises, this series of equipment has developed to the fifth generation.
Gold Electrowinning Equipment,Mining Equipment,Gold Process Equipment,Gold Processing Equipment Changchun Gold Research Institute Co.LTD , https://www.changchungoldresearch.com
Five indicators to judge the quality of full color LED display
With the application and wide promotion of full-color LED display, the display effect of LED display is directly related to users and audiences. In order to obtain a perfect experience, it is necessary to control and improve the quality of LED display. The following editors will talk about the factors related to improving and controlling the quality and effect of LED full color display. What is the importance of LED display devices? First of all, LED is the key component used in the full-color screen machine. It uses thousands to tens of thousands of LEDs per square meter. Secondly, LED is the main body that determines the optical display performance of the whole screen, directly affecting the audience's evaluation of the display. Again, LEDs account for the largest proportion of the overall cost of the display, ranging from 30 to 70. The choice of LED determines the quality of the entire display 50 or more. If the LED is not selected, the other components of the LED display can no longer compensate for the defects of the display quality. What are the important indicators that reflect the quality of LEDs for full-color LED displays? First, LED display brightness LED brightness is an important determinant of display brightness. The higher the brightness of the LED, the larger the margin of current used, which is beneficial for saving power and keeping the LED stable. LEDs have different angle values. In the case where the brightness of the chip is fixed, the smaller the angle, the brighter the LED, but the smaller the viewing angle of the display. Generally, a 100 degree LED should be selected to ensure a sufficient viewing angle of the display. For displays with different dot pitches and different line of sight, a balance should be found in brightness, angle and price. Second, LED display failure rate Because the full-color display is composed of tens of thousands or even hundreds of thousands of red, green and blue LED elements, the failure of any color LED will affect the overall visual effect of the display. Generally speaking, according to industry experience, the failure rate before the LED display starts to assemble to the aging 72 hours before shipment should be no more than three ten thousandth (refer to the failure caused by the LED device itself). Third, LED display consistency Full color display is composed of countless red, green and blue LED elements. The brightness and wavelength consistency of each color LED determine the brightness consistency of the entire display. White balance consistency, chroma consistency. In general, display manufacturers require device vendors to provide LEDs with a wavelength range of 5 nm and a brightness range of 1:1.3. These specifications can be achieved by device suppliers through a spectral color separation machine. The consistency of the voltage is generally not required. Fourth, LED display anti-static ability LED is a semiconductor device, sensitive to static electricity, it is easy to cause static failure, so anti-static ability is critical to the life of the display. In general, the LED static voltage test failure voltage should not be lower than 2000V. 5. LED display attenuation characteristics Red, green, and blue LEDs have the characteristics of brightness decay with increasing working time. The advantages and disadvantages of the led chip, the quality of the auxiliary materials and the level of the packaging process determine the attenuation speed of the LED. In general, after 1000 hours and 20 milliamperes of normal temperature lighting test, the attenuation of red LED should be less than 10, the attenuation of blue and green LED should be less than 15. The consistency of red, green and blue attenuation for the full color LED display in the future The white balance has a large effect, which in turn affects the display fidelity of the display.