Brightness index of the hottest projector

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Projector brightness index

with the development of projector products, manufacturers continue to launch projector products with higher brightness, and the brightness of the projector has reached more than 2000ansi lumens. However, in the process of purchase, users often have a biased understanding of the projector brightness index. Machines of different brands and the same brightness index also differ greatly in comparison, so how to understand the projector brightness index

light out is the technical index to turn off the switch after the projector main (3) experiment. Light out is usually expressed in luminous flux, which describes the ability of light source radiation to produce visual response in unit time, and the unit is lumen

lcd projector indicates the unit of luminous flux is ANSI lumen. ANSI lumen is a method for measuring the luminous flux of projector developed by American National Standardization Association. It measures the illuminance of each point on the nine intersection points of the field shape of the screen, multiplies the area, and then calculates the average value of the nine points, which is the ANSI lumen value of the projector, The light output of the LCD projector mainly depends on the brightness of the light source, the light path system and the transmission or reflection ability of the LCD panel. At present, high brightness projectors improve light through technology without increasing the power of light source. 1. Understand the functional utilization of parts, set P.S light conversion board on the light path, and turn the s light reflected and transmitted in the vertical direction after deflection to improve the efficiency of light. The brightness unit of DLP projector is ANSI lumen. DLP projector (digital light processing technology Texas Instruments Technology) uses digital micro mirror device (DMD) as light valve imaging device to output large screen image through signal amplification. Most DLP projectors use a DMD light valve to rotate colors with a color filter. Liquid crystal projectors and DLP projectors are the main models in the Chinese market at present. Due to the difference of the test environment, the ANSI lumen indicators of the machines of various brands are different. However, the ANSI lumen value provided by the manufacturer basically reflects the brightness level of the projector

the light output of CRT (three gun) projector is represented by peak lumens, that is, on the test image of a white window, when the scanning line is still clearly visible, measure the maximum illumination (Lux) of the white window multiplied by the area of the white window (M2) to determine the luminous flux of the projector. Peak lumens have good practical significance, because any video image you see cannot be all white fields, The proportion of white generally accounts for about 20% of the image area. At the same time, CRT projector relies on the electron beam in the projection tube to scan and obtain images on the fluorescent screen. The beam current depends on the emission capacity of the cathode. Under normal conditions, the electrons emitted by the cathode are controlled by the negative potential difference between the cathode grids, forming an electron cloud between the cathode grids. With the potential decreasing, the electron flow is quickly pulled to the anode - fluorescent screen. CRT tube can provide high pulse current, so the brightness of the window signal on the screen can be high, If the picture is full white field, due to the limitation of cathode emission capacity, only the average beam current can be provided, and the brightness of the screen will be greatly reduced, only about 1/5 of the peak current. Due to the different sizes of CRT projections and window signals used in the cathode, but they all need the high performance (10% - 25%) provided by Solvay medical grade plastic, the brightness indicators of products from various manufacturers are not absolutely comparable. In the test and user use of projector brightness, it has a great relationship with the distance between the projector and the screen, the screen angle of view, and the gain index. It is also a point that needs attention

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