In the modern world, any trainings, negotiations at work, and even school lessons are not complete without appropriate presentations. And no wonder, because with the help of images people quickly and better absorb information. To present to others a product, document, report or any picture on the screen, it is enough to use a computer, TV or a special device to view illustrations. The name of the device for viewing slides, as well as the types of these devices will be discussed.
What it is?
If someone still has not recalled the name of the slide show device, then this is a projector. Such devices allow you to receive images on a remote screen by geometric projection.
These devices appeared on the electronics market for a very long time, but only a few years ago they became not an expensive “pleasure” for the rich, but a common technique that can not be avoided during presentations at work or in educational institutions. At a price, devices for viewing slides are now almost identical to widescreen TVs, so any consumer or company can afford to buy such a device.
Types of projectors by size
The first thing these devices decided to classify by their dimensions. Depending on this parameter, they are:
- Stationary, which are the largest, most expensive, but functional devices. Such projectors are installed in a strictly designated place, such as DVD players and similar devices. They are often used both by large companies and ordinary users, at home. Stationary devices for viewing slides, in addition to high functionality, there are other features. For example, various modern interfaces, the capabilities of "intelligent" control, etc.
- Portable, which, unlike the previous version, can be moved from place to place, which is especially important, for example, for educational presentations. Although they are compact, in quality, characteristics and functionality they are practically not inferior to stationary devices.
- Pocket ones that are great for users spending all their time on the go. Such devices can be carried with you anywhere and anytime, because on average the mass of such devices is only 200-300 g.
- Ultraportable projectors. They are more compact than handheld devices, but less functional. Suitable only as an additional device for creating simple presentations.
Types of projectors by resolution
Each slide viewer is also classified according to other characteristics. For example, by resolution, i.e., by the value that determines the number of dots (pixels) per unit area (inch). Depending on this parameter, there are:
- Conventional projectors: SVGA (800 x 600), XGA (1024 x 768) and SXGA + (1400 x 1050), with a 4: 3 aspect ratio.
- Widescreen projectors: WXGA (1280 x 768, 5: 3), WUXGA (1920 x 1200, 8: 5), HD 720p (1280 x 720) and Full HD 1080p (1980 x 1080). The latter are the most common formats on the modern electronics market. The aspect ratio of both projectors is standard - it's 16: 9.
But when choosing, you need to pay attention not only to the resolution of the device for viewing slides. The screen views of these devices also play an important role. Everyone can reproduce a picture in different ways, even despite a decent format. Therefore, in order to get really good quality slides, you need to proceed from the ratio of resolution and screen sizes combined.
Types of projectors by their functionality
Today, both old and new devices are present in the technology market. Of course, the new products have rich functionality, while past models can no longer surprise a modern user. Therefore, in order not to be mistaken with the choice of device, this classification exists:
- codoscopes;
- slide projectors;
- bishops;
- multimedia devices.
Codescopes
Often such devices are called graph projectors. The principle of their operation is quite simple: the projected original is superimposed on the condenser (drawing, diagram, picture drawn on a special transparent film), and due to the vertically located lens and the mirror mounted at an angle, the light changes its position to horizontal, getting on the screen, which can be an ordinary wall or a whiteboard.
Now such devices for viewing slides are not produced and are practically not used, since they have many disadvantages. For example, PCs and laptops cannot be connected to them, and creating pictures for presentations takes too much time.
Popular models: "Lecturer-2000", "Bearing-2400", "Liter-1400".
Slide projectors
Still similar devices are called slide projectors. In fact, these are advanced analogues of codoscopes. They are also designed to view only still pictures drawn on transparent film. The only advantage of such devices over kodoskopa is ease of use. If in the previous version it was necessary to manually overlay pictures on the condenser (some of them also draw on their own), then slide projectors, for example, the carousel type, saved users from such torment. In such devices special “shops” are used, where up to fifty small-format slides can be stored at one time.
Unfortunately, such devices are rarely used to create presentations. Their main and only drawback is the inability to connect to a PC or laptop.
Popular models: "Diana-207", "Alpha-35-50", "Twinkle", "Lecturer-600", "Bearing-600", "Light", etc.
Bishops
If you need to project an opaque object (a photocopy of the page of a book, a drawing on paper, etc.), then this apparatus is perfect for viewing slides. The features of the bishop are also that it does not need to be prepared for work. It is easy to use and shows a fairly high quality image. And the material for the presentation can be anything: from a book to a sketch on a notebook page.
Modern devices
And finally, the most common device for viewing slides is a multimedia projector. Depending on the technology on the basis of which the device was created, there are:
- DLP projectors that create an image thanks to a matrix and several mirrors, each of which rotates under the influence of specific signals. Such devices show pictures of very high quality with deep detail, which is why they are much more expensive than analogues.
- LCoS projectors that are not inferior in performance to devices with DLP matrices and even a little better than LCD devices. Judging by user reviews, such devices show a fairly clear picture, without blurring and "mesh" effect.
- LCD projectors that are almost out of production. They work with a matrix of red, blue, green and light coming from the lamp. User reviews about this product are quite controversial. Some note that for a small cost, LCD projectors work stably, show relatively high-quality images. Others say that the pictures in most models are obtained with a "mesh" effect.
- CRT projectors (kinescope) - reliable, functional stationary devices, with high image quality. The only drawbacks of such devices are the complexity of the installation, the high weight and high cost in the market.
Popular models of multimedia projectors: Acer X117H, Benq MS, Epson EB, Tecro PJ, Vivitek DW, Asus S1, etc.