Projectors

Projector is a device used for displaying video, images or computer data on a screen or other flat surface. It is a modern equivalent of the slide projector or overhead projector.

A projector projects a sufficiently large image to be viewed by every student in the classroom without causing eyestrain.

Classroom Benefits of Projectors​​​

• Highly effective as a means of instruction or demonstration in classrooms, computer rooms, staff training, or parents groups.​
• Presenting students work to the whole class. ​
• Image projection in conjunction with wireless mouse/keyboard, wireless slate, a visualiser, or an interactive whiteboard. ​
• Displaying and browsing Web sites in a controlled and collaborative manner.​
• Demonstrating or using educational software in a whole class context.​
• In conjunction with a TV, video or internet source, a digital projector provides a means of presenting video to student/parent audiences.​
• ​As a means of display/interaction in a classroom situation. Students with special needs can particularly benefit from material being presented visually as it can aid in both information processing and retention.​
• Enhancing professional development with staff groups via large screen projection​.
• Facilitating video conferencing via large screen group participation​.

​​Types of Classroom Projectors


Projectors are of 3 types - namely LCD, DLP and CRT. Other than this, projectors may be classified as long throw, short throw and ultra short throw projectors.

While traditionally LCD projectors have been used extensively in schools, DLP is the newer technology. DLP (Digital Light Processing) projectors are ideal for both home and classroom use. An LCD projector provides the brightest and sharpest output similarly a DLP projector has the best contrast ratio which is important in projectors for classroom. A CRT projector is a video projector that uses a small, high-brightness CRT (or picture tube) as the image generating element. The image is then focused and enlarged onto a screen using a lens kept in front of the CRT face.​

Further 3D ready projectors and interactive projectors have also made their way into classrooms in India.



LCD vs DLP Technologies



There are two main projector technologies available when you are considering what type of projectors to get. LCD (Liquid Crystal Display) is the most common type of data projector available. DLP (Digital Light Processing) is a more recent technology which used thousands of tiny mirrors to create the image. It is smaller than a LCD projector filling a demand for small light weight projectors. Both technologies are suitable for schools.

1. Short throw Projector - A shorter throw distance will result in a bigger picture being projected, if the distance between the projector and the projection screen is kept constant. For further effect a short throw lens can be used to project an even larger image. Some projectors, come pre-installed with a short throw lens and can thus project a 48-inch diagonally wide image from only 4 feet way. Projectors with short throw distances are suited to those people that require portability, or for those people that need to use their projector and screen in smaller environments.
2. ​​​Long Throw Projector - A longer throw distance allows for smaller, sharper images to be projected from further distances away. A longer throw lens is preferable if you intend to use your projector in large, expansive surroundings. In these situations a long throw lens will most likely be required to make sure that the quality of the projected image is maintained while moving the projector further away from the screen.
3. Ultra-short throw Projector - The new ultra-short throw projector design eliminates many of the common problems of interactive systems, such as an eye glare. Anchored close to the wall, you can project extra-large images with the lens only inches away. Even when standing directly in front of the screen, the light rarely reaches the face, making it easier on the eyes. This makes standing in front of the screen far more pleasant. Shadow interference has been reduced significantly. Previously obstructed areas of the screen are now clearly visible to make sharing of information smoother.