Introduction
An overhead projector is a machine that projects images from a transparent medium onto an opaque object (Reddy, 2023). The material that is to be projected is placed onto the roller tray or document tray, depending on its form (Reddy, 2023). The projector projects images onto a selected surface by holding the transparent medium in place, using two rollers, and making use of a white light (Reddy, 2023). The white light, passes through converging lenses, onto the lit-up transparent medium, and projects an image onto the given surface (Shrader, 2023). When using an overhead projector, one must adjust the focus in order for the projected image to be clear (Reddy, 2023). The following video by the Computer History Museum describes how the overhead projector is used in a more detailed manner:
It is still used by people today as it is an easy way to share a document with a group of people (Reddy, 2023). A modern projector provides the same uses as the older overhead projector but is backed up by modern technology. It is often useful in educational settings as well as business settings (Reddy, 2023). More specifically, the evolution of the projector has helped improve the educational system in areas of class participation, student presentations as well as teaching methods (Kahl, n.d.).
Evolution
Overhead projectors experienced many phases of development before reaching the stage they are at today. The changes overhead projectors went through were in relation to the weight of the projector, its dimensions, as well as the technology it utilizes (Akanegbu, 2013). The overhead projector specifically was a result of the evolution of the magic lantern, which was invented in the late 1800s, and the filmstrip projector that came after that in 1925 (Akanegbu, 2013).
The magic lantern made use of candles and oil lamps in order to project images that were on glass slides (Akanegbu, 2013).
As for the filmstrip projector, it allowed educators to use educational filmed material in their classrooms (Akanegbu, 2013). Both of these technologies were applied in the educational sector as well as other sectors (Akanegbu, 2013).
After the filmstrip came the overhead projector, which was invented by Roger Appeldorn while he was working at 3M (Akanegbu, 2013). At first, overhead projectors were used in World War 2 to prepare servicemen (Reddy, 2023). After that, overhead projectors were introduced to educational entities (Akanegbu, 2013). In the present day, the overhead projector is still somewhat present as it led to the development of the advanced modern projector used nowadays (Akanegbu, 2013).
Affect on Education
It has been proven that projectors have enabled an improvement in classroom participation as they display information that is clear and that can be read from a distance (Kahl, n.d.). Projectors also allow greater efficiency because educators do not have to rewrite the information on the board for all the sections they teach (Kahl, n.d.). Additionally, projectors have made room for more advanced student presentations because of the modern technology available (Kahl, n.d.). Thus, the projector has enhanced education in many ways and affected the reading and writing practices used in the classroom setting.
Personal Commentary
I have personally been very interested in the more modern projector and have used it for entertainment as well as for education. As for entertainment, I frequently make use of a projector when enjoying movie nights with my younger cousins. During our winter movie nights, I make use of the projector as it displays the video in a large manner and allows us to experience a group bonding activity together.
As for education, I grew up in an educational setting filled with modern technology, including projectors. I have had to switch them on and off, wait for IT to come and fix them, and have gotten used to their form of display of a presentation. I have had to both write down information from a presentation displayed by a projector as well as read the text displayed out loud. I have found that projectors affect writing and reading in a positive manner as they lead to group interactivity as well as efficiency in education.
References
Akanegbu, A. (2013, February 28). Vision of learning: A history of classroom projectors. Ed Tech. https://edtechmagazine.com/k12/article/2013/02/vision-learning-history-classroom-projectors
Computer History Museum. (2016, September 12). PowerPoint demonstration: Overhead projectors. YouTube. https://www.youtube.com/watch?v=Nqf1DKSXJro
Kahl, C. (n.d.). Education projectors: A staple of the history classroom. Projector Reviews. https://www.projectorreviews.com/articles-guides/education-projectors-a-staple-of-the-history-classroom-2/
Overhead projector. (n.d.). RC Events. https://rcspecialevents.com/projectors/overhead-projector/
Reddy, J. (2023, January 3). How do overhead projectors work. ProjectorCATalog. https://projectorcatalog.com/how-overhead-projectors-work/
Shrader, F. (2023, September 7). How does an overhead projector work? Visual Finds. https://visualfinds.com/projector/how-does-an-overhead-projector-work/#:~:text=Overhead%20projectors%20are%20the%20most
The magic lantern: A history and demonstration. (2023). NYU. https://tisch.nyu.edu/content/dam/tisch/cinema-studies/events-publicity/f18/magic-lantern.jpg.preset.sixteen-nine.jpeg
Warren, Y. (2015, October 6). 1925 filmstrip-projector-500. Flickr. https://www.flickr.com/photos/136738808@N06/21387683144