The conversion formula of projection distance and projection size, simple method!

When purchasing a projector, we first pay attention to important parameters such as the brightness, resolution, contrast, and uniformity of the projector. In addition, we also need to figure out the focal length of the projector and the size of the liquid crystal film so that the projection distance and image The size is suitable for our use occasions. The projection distance and screen size are closely related to the focal length of the projector and the size of the liquid crystal film. The relationship is as follows: 　　 Known screen size to get the projection distance: 　　Minimum projection distance (m) u003d Minimum focal length (m ) x screen size (inch) ÷ LCD size (inch) 　 　 maximum projection distance (m) u003d maximum focal length (m) x screen size (inch) ÷ LCD size (inch) 　 　 known projection distance to get the screen size: 　 　 maximum projection screen (M) u003d projection distance (m) x LCD size (inch) ÷ minimum focal length (m)　　 minimum projection screen (m) u003d projection distance (m) x LCD size (inch) ÷ maximum focal length (m)　　 Example: 　　1 The focal length of Toshiba TLP-S71 is 26.5mm~31.5mm, and the size of the LCD panel is 0.7-inch LCD panel, which requires an 85-inch screen. Minimum projection distance (m) u003d 0.0265 meters x 85 inches ÷ 0.7 inches u003d 3.217 meters Maximum projection distance (meters) u003d 0.0315 meters x 85 inches ÷ 0.7 inches u003d 3.825 meters 2. Known: EPSON EMP-6000 focal length is 24.0- 38.2 mm, the size of the LCD panel is 0.8 inches LCD panel, the projection distance is 4 meters, 'request: the largest projection screen and the smallest projection screen. Maximum projection image (inch) u003d 4 meters x 0.8 inches ÷ 0.024 meters u003d 133.3 inches Minimum projection image (inches) u003d 4 meters x 0.8 inches ÷ 0.0382 meters u003d 83 inches The projection image size mentioned above, we need to according to the projection image size Select the size of the projection screen. The screen size we are talking about now is actually the length of the diagonal of the screen, in inches. Generally speaking, the ruler scale in our country is meters, and it is more convenient to measure the length and style, so it is necessary to know the conversion formula of the screen width (meters) and the screen height (meters) according to the screen size (inches): 1 inch u003d 2.54 cm u003d 0.0254 The ratio of the width to the height of the ordinary screen is 4:3, so it is obtained from the Pythagorean theorem: 　　 screen width (m) u003d screen size (inch) x 0.0254 m/inch x 0.8 u003d screen size ÷ 50　　 screen height (m) u003d Screen size (inch) x 0.0254 m/inch x 0.6 u003d screen size ÷ 66　　 The unit obtained is meters. According to this formula: 　　 the width of a 60-inch screen is 60÷50u003d1.2(m) The height is 60÷66u003d0.909(m) )　　The width of the 150-inch screen is 150÷50u003d3(m), the height is 150÷66u003d2.27(m) 　　The width of the 200-inch screen is 200÷50u003d4(m) the height is 200÷66u003d3(m) )　　According to the above calculation company, we can calculate by ourselves. Of course, there are some softwares available now. If you want to be lazy, you can download one.