ANSI lumens

The brightness of the projector: "light out" is the main technical indicator of the projector. "Light out" is usually expressed as luminous flux. Luminous flux is the ability to describe the visual response of the light source radiation per unit time. The unit is lumens. The projector indicates that the international standard unit of luminous flux is ANSI lumens, and ANSI lumens is a method for measuring the luminous flux of a projector developed by the American National Standards Institute. The measurement environment is as follows:
1) The distance between the projector and the screen: 2.4 meters.
2) The screen is 60 inches.
3) Measure the illuminance at each of the nine intersections of the “Tian” shape of the screen with a meter pen, multiply the area, and obtain the brightness of the nine points on the projection screen.
4) Find the average of the brightness of 9 points, which is ANSI lumens.

Comparison of brightness: LCD projectors are transmissive projection methods, mainly rely on improving the efficiency of light sources, reducing the energy loss of optical components, increasing the aperture ratio of the liquid crystal panel and installing microlenses and other technical means to improve the brightness. DLP technology belongs to the reflective projection method, which mainly improves the brightness index by improving the color wheel technology, changing the tilt angle of the micromirror, and reducing the optical path loss. With the development of projector products, various manufacturers have continuously introduced projectors with higher brightness, and most of the brightness of projectors has reached 2000 ANSI lumens or more. Since the projectors of various brands have different measurement environments, the actual brightness is different, although the ANSI lumens are the same.

The brightness of the projector is closely related to the distance between the projector and the screen, the viewing angle of the screen, and the gain index of the screen. Differences in products with different brightness are mainly manifested in the sharpness of the image, the sharpness of the color, and the gray level of the light and dark areas. That is, the images of the products with higher brightness are clearer, the sharpness of the color is higher, and the bright and dark areas are darker. The grayscale performance is more complete. For ordinary text applications, the difference in brightness has no obvious effect on the image. Different manufacturers have different differences in brightness adjustment settings. Most products can display images clearly and completely in the brightness adjustable range. After some products are adjusted to 90% or more in brightness, the screen is blank, and such high brightness is The actual application of the user obviously has no practical significance.

Projector brightness and screen selection: Brightness is the intensity of the light output from the projector's output to the screen and the brightness of the projected image. In general, the higher the brightness of the projector, the brighter the same-size image projected on the screen, the clearer the image. However, the brightness of an image that the human eye can sense does not only depend on the brightness of the projector, but also has a great relationship with the ambient light intensity and the size of the image. The stronger the ambient light, the darker the brightness of the image perceived by the human eye. Therefore, the user must select the appropriate brightness according to the environmental conditions used by his projector, not necessarily the brighter the better. Because the other indicators are the same, the higher the brightness, the higher the price of the projector, and the brightness of the perceived image of the human eye will have a certain range, beyond this range, the human eye will feel uncomfortable, especially for a long time Excessively bright images can cause fatigue to the human eye and cause some damage.

The user needs to be reminded that, in addition to selecting the brightness index according to the size of the space, the user must also consider factors such as lighting conditions and screen types used in the environment. The same brightness, different ambient light conditions and different screen types will produce different display effects. When the user selects a projector product, there is a margin for the brightness index. Since the brightness of the projector largely depends on the light bulb in the projector, the brightness output of the light bulb will be attenuated with use time, which will inevitably cause the brightness of the projector to drop. After 2000 hours of use, the brightness of the projector is attenuated quickly. Therefore, when selecting a projector product, the user must have a comprehensive consideration of the brightness index.

In general, in the 40-50 square meters home or the living room, the projector brightness is recommended to choose between 800-1200 lumens, the screen corresponding to the choice of 60 inches to 72 inches; 60-100 square meters in a small conference room or standard classroom , The projector brightness is recommended to choose between 1500-2000 lumens, the screen corresponds to the choice of 80-inch to 100-inch; in the 120-200 square meters of medium-sized meeting rooms and amphitheatre, the projector brightness is recommended to choose between 2000-3000 lumens, the screen corresponds Choose 120-inch to 150-inch; in the large-scale conference room or auditorium of 300 square meters, most projectors should select professional engineering machines with 3000 lumens or more, and the curtains are all over 200 inches.