ProjectorsBefore the invention of projectors, people needed to display images through movie projectors or slide projectors. These devices are not only bulky and complex to operate, but also have low brightness, and the effect is not satisfactory. With the development of science and technology, projectors came into being, bringing revolutionary changes to image display.
1. First of all, it is necessary to clarify the nature of the source to be displayed.
That is, what is its line frequency and what graphics card outputs it. According to the nature of the displayed source, the projector can be mainly divided into two categories: ordinary ** machine and digital machine. When only the full TV signal is displayed, such as the karaoke hall ** videotape, you can choose the ordinary ** machine;To display the signal output from the VGA card, you can select the digital machineAll NEC models have both ** and digital inputs.
2. Confirm the installation method.
The installation method of the projector is divided into table type front projection, ceiling front projection, table type rear projection, and ceiling rear projection. The front projection is the projector and the viewer on one side;Rear projection is when the projector and the audience are at opposite ends of the screen. If you want to use it temporarily, you can choose the table-mounted ceiling method. If the space is large, there is an overall arrangement during civil construction, and the overall effect of choosing the rear projection method is the best, such as the space is small, you can choose the rear projection refraction method.
3. Find out the display environment, such as the size of the room and the lighting.
If the room size is small, an LCD projector is optional. When the display area is large, there is no daylight, and the lighting is dim, you can choose a low-brightness projector of about 800-1200ANSI. When the requirements for ambient light are not high, the display area is extraordinarily large, and the display of high-resolution graphic signals is displayed, DLP projectors can be selected.
4. Projector on-site purchase skills.
After determining the selected model, under the condition of on-site power-on, how to identify the actual indicators of the projector through the projected picture?
Check the horizontal scanning tracking frequency rangeAccording to the horizontal scanning frequency range given on the technical index, select the high, medium and low frequencies from them, and calculate the image resolution corresponding to the three frequency points. Check whether the projector can display properly at these three resolutions. If the lines are out of sync, that is, the screen is twisted or shaky, it means that the horizontal scanning tracking is poor.
Check the focus performance Use the test grid generated inside the projector, or the test grid generated by the signal generator or computer, adjust the focus to the optimal position, change the image contrast from low to high, and observe whether the horizontal and vertical lines of the square are out of focus. If there is, it means that the focus performance is poor.
Check the details of the Bandwidth that directly affects the bandwidth. Use a computer or signal generator to generate the highest resolution white background graphics signal that a projector can achieve, and observe whether the smallest characters on the screen are clear. For example, when the bandwidth of the projector is insufficient, the horizontal lines displayed on the screen are solid, and the vertical lines are blurred, and the image details are blurred.
An on-site inspection of the LCD projector produces an all-white image to see how uniform the colors are. Generally speaking, it is difficult to achieve a high standard of color uniformity for liquid crystal speculation. However, the color uniformity of the projector is relatively better. In addition, the dust protection of LCD projectors is a problem, and a small amount of dust, if it falls on the LCD panel or lens, can be magnified very clearly. If there are any color spots on the screen when adjusting the optical focus from small to large on the all-white image, it may be that there is dust on the LCD panel or lens, and it is estimated that there is a problem with the machine's dust-proof system.
The working principle of the projector is mainly by projecting an image or ** signal onto the screen to form a clear and bright picture. Modern projectors often use digital technology, which is capable of delivering higher resolution and richer colors. There are many types of projectors, which can be selected according to the usage scenario and needs.
In addition to home entertainment, projectors also have a wide range of applications in education, business, and medical fields. In the field of education, projectors can be used to display teaching materials and PPT presentations to improve the teaching effect. In the business world, projectors can be used for meetings and training, making content more lively and interesting. In the medical field, projectors can be used in operating rooms and centers to provide clear images and information.
In short, as an important image display device, projector has penetrated into all aspects of people's lives. Its emergence has not only changed the way people are imaging, but also greatly enriched people's cultural life. With the continuous development of science and technology, the performance and function of projectors will continue to improve and improve, bringing people a better visual experience.