Projector purchase

1, clear the nature of the source to be displayed

That is, what the line frequency is, is output by the display card. According to the nature of the displayed source, the projector can be mainly divided into ordinary video machines and digital machines. When displaying only full-TV signals, such as playing video tapes in a karaoke bar, you can select ordinary video machines; to display the signals output by VGA cards, you can select a digital camera; and all NEC models have both video and digital inputs.

2, confirm the installation method

Projector installation methods are divided into table type front projection, ceiling projection, table rear projection, ceiling rear projection. The front projector is the projector and the viewer is on one side; the rear projector is the projector and the viewer is on the screen both ends. If you use it temporarily, you can choose the table ceiling method. If the space is large, there are overall arrangements for civil engineering. The overall effect of choosing the rear projection method is the best. If the space is small, the method of rear projection can be selected.

3, find out the display environment, such as room size, lighting conditions

If the room is small, LCD projector is optional. When the display area is large, there is no sunlight, and the lighting is dark, a low-brightness approximately 800-1200 ANSI projector can be selected. When the demand for ambient light is not high, the display area is large, and high-resolution graphics signals are displayed, an LCD projector can be selected.

4, projector on-site buying skills

Checking the Horizontal Sweep Tracking Frequency Range According to the horizontal sweep frequency range given on the technical specifications, the high, medium, and low frequencies are selected from the middle to calculate the image resolution corresponding to the three frequency points. Check if the projector can display properly at these three resolutions. If the line does not synchronize, that is, the screen twisted or jitter, etc., indicating poor horizontal scanning.

Checking the focusing performance Use the test box generated inside the projector, or the signal generator and computer-generated test grid, to adjust the focus to the best position, change the image contrast from low to high, and observe the horizontal and vertical lines of the square. Is there a defocusing phenomenon? If yes, it indicates poor focusing performance.

Check video bandwidth Video bandwidth directly affects the details of the video. Use a computer or signal generator to produce the highest resolution white-colored graphics signal that the projector can achieve. Observe the clarity of the smallest character pattern on the screen. If the video bandwidth of the projector is insufficient, the horizontal lines appearing on the screen are more real, and the vertical lines are virtual, and the details of the image are blurred.