Document camera

Document cameras do not require the lights to be dimmed in the room they are used in, contrary to what overhead projectors need to be visible.

The first document camera, known as a visualizer, was developed by Wolf Vision and Elmo and launched at the Photokina Trade Fair in 1988.

[6][7] During the mid-1970s, these were assembled and equipped with additional lighting to provide a consistent quality of the projected image and enable use in a darkened room.

A prism is used to split white light into its red, green, blue components, and a separate sensor is then used for each color.

Some document camera models integrate additional functionality into the light system, such as a synchronized light field that indicates to the user at all times, by way of an illuminated image capture area or laser markers, the size and position of the imaging area, which adjusts simultaneously as the lens zooms in or out.

Larger resolutions and high refresh rates generate large amounts of data that must be processed in real time.

Document cameras can be equipped with a range of advanced automated systems designed to enhance ease of use and improve functionality and image quality.

In addition, an external PC or laptop can be connected to the document camera to allow for switching between a Power Point presentation and a live demonstration.

Some models can also handle external storage devices and play files directly from a USB flash drive, or save images taken during the presentation onto it.

[9] Document cameras are generally divided into three groups: Portable and desktop models allow a working environment similar to an overhead projector.

Ceiling-mounted document cameras/visualizers are a variation from the traditional desktop models and allow for larger objects to be displayed.

There is no desktop technical equipment to restrict the views of the speaker and audience, as the technology is installed unobtrusively in the ceiling.

This includes, in particular, documents of varying sizes and shapes, stapled, in folders, bent, or crumpled, which may get jammed in a feed scanner.

ADF scanners, whilst very fast and very good at batch scanning, also require pre and post-processing of the documents.

[12] While scanning large batches of un-stapled documents, ADF scanners can be more efficient when compared to these cameras.

These cameras may face challenges with certain environmental conditions such as poor lighting, which may decrease the quality of scanned documents.