A Rhyme of History: Document Camera
The document camera can be described as an image projector or digital projector. You can lay a piece of paper on it and write or draw on it to delineate a concept or theory being taught. Whatever is written is projected on a screen for the audience to see. The document camera rekindles the overhead projector in the respect that it project an image in real time and allows for real time modification that can be viewed by the targeted audience, and it is portable as the overhead projector was. Visit http://www.visualedtech.com/What%20is%20a%20document_camera.htm for a full description of the document camera.
Below is a picture of the overhead projector.
Below is a picture of the document camera.