A video magnifier is a device that basically captures an image of an object and then allows viewing of that object on a monitor or screen with various levels of possible magnification. These types of devices are available in a number of different models, though they are typically designed as a desktop device that can capture images from a piece of paper or other object placed under a camera and then display that image on a large screen. A video magnifier can also be a device designed with a projector, which allows an image scanned or captured by the device to be projected onto a screen, wall, or other large object.
The purpose of a video magnifier is typically to allow someone to scan or capture an image through a digital video camera and then display that image on a screen. This type of device is often used by people with visual impairments, to render pages of a magazine or other documents larger for easier viewing. A desktop video magnifier, for example, usually has a small platform with a raised arm that supports a monitor. Documents can be placed on this platform, over which a camera is located, and then displayed in real time on the monitor, with additional controls to increase magnification and zoom in on particular areas of the image.
There are also portable devices that can be used as a video magnifier, usually including a smaller camera and a small display that is part of the device. While this type of magnifier may not present a large overall image in the same way a desktop device can, it is capable of zooming in on a small region of text or an image and making it larger. This can allow someone who has difficulty reading small text to use a portable video magnifier to read menus in a restaurant or more easily perform research in a library.
A video magnifier can also include a projector to magnify an image and project that zoomed-in aspect onto a screen or other large surface. Artists can use these types of magnifiers to scan a picture or other object, and then project a larger version of it onto a canvas for use in creating an original work. A video magnifier can also refer to a fairly large magnifying glass or sheet that can be placed over a computer monitor or other display. This usually clips onto the monitor and increases the size of objects on that display, for easier viewing by people with visual impairments.