How do you choose the right digital projector for your classroom?
Digital projectors serve a number of purposes – for big screen entertainment (movies and video-based gaming), business presentations, and for classroom instructions. A great majority of schools and other institutions of learning have taken advantage of the benefits of an LCD projector as an effective way of teaching lessons in class and engaging the students.
And while some schools have used LCD projectors for a long time before the other schools did, they might have to consider replacing their old projectors as there are numerous choices in the market that are affordable, with more features and functions, more compact and more sleek-looking. Moreover, there are more variations to the standard and conventional LCD projector.
Overhead projectors (OHPs) have been used in many schools in earlier years. If you go back a few years and recall how your school had the OHP pushed from one classroom to the next. Teachers spend time and energy in preparing their transparency films to be used with the OHP. The OHP was a basic and effective teaching tool in the past.
Digitalized LCD Projectors
Today, like everything else, digitalization has not spared LCD projectors. They are now available in smaller and more compact forms. They now display video images and computer data not to mention that they are more affordable, too.
Two Technologies Used In Digital Projectors
Digital projectors can be any one of these two common technologies: digital light processing or DLP, and 3LCD or liquid crystal display.
Digital Light Processing (DLP)
This is a 1-chip DLP system where the white light shines through blue, red, white and green parts of a color wheel that rotates onto a DLP chip. This chip is synchronized with the color wheel, creating thousands of pulses of colored light per second. A digital micromirror device (DMD) reflects the rapid light pulses. The DMD is a semiconductor chip made up of microscopically small mirrors and each mirror represents one or more pixels in the projected image.
Liquid Crystal Display or 3LCD
This technology works differently than the DLP. A sequence of dichroic mirrors handles the separation white light into green, blue and red light. Each color is passed through an individual LCD panel after which the colors are re-mixed through a prism that projects it on the screen. Using the three basic colors in each pixel of the projection, the rainbow effect is avoided and the final projected image comes out in crisp and sharp quality.
When choosing either a DLP or 3LCD, it is important to check two things:
- The life cycle of the DLP or LCD projection lamps
- The DLP or LCD projector has a shorter range
A shorter range means having the projector closer to the projection space and this is ideal for small classrooms because there is less chance of obstacles and the teacher can be more interactive with the students on what is being projected without blocking the light.
Are you using a DLP or 3LCD?