Data Projectors in Schools
by Keith Lightbody
last updated 5 March 2007
A data projector is a device that takes a signal from a computer, TV or video source and produces a large image using projected light.
1. Quick Start:
You can quickly set up a data projector to display a large image on a screen or light coloured wall.
Place the computer and projector on a suitable surface a few metres from the screen or wall.
Plug one end of the display cable into the projector and the other end into the computer
(typically each plug will only fit a single location).
Plug in power leads for the projector and the computer
(recommended to plug in power for laptop in case battery goes flat during presentation).
Optional: plug in the lead to support remote control unit or mouse (usually USB).
Turn on the projector and then the computer (order may not matter on recent models).
Wait for the projector to warm up and display an image
If using a laptop you may need to cycle through the 3 possible options - display on LAPTOP ONLY, display on SCREEN ONLY or display on both LAPTOP AND SCREEN. This is typically done by keeping down the FUNCTION or FN key and tapping just once on the function key with an icon that looks like 2 screens (often F3, F4 or F5). After each press WAIT at least 10-20 seconds to allow the projector to display the selected source.
Once you have the display on screen adjust the focus.
Adjust the image size using zoom controls or by carefully moving the projector closer or further from the screen (do not bump the expensive lamp).
Load you presentation and set to the opening screen
If required check that pointer or remote control are functioning correctly
When finished check that your computer screen is active then press the projector off or shutdown button (typically red) - this will commence a cooling down cycle for which you should allow at least 5 minutes - DO NOT PACK UP A PROJECTOR UNTIL IT IS COOL.
2. Curriculum Benefits:
Communication is a key learning skill and a data projector allows a teacher or student a whole new dimension in how they share ideas, information, charts, images, animations, audio or video. Learning is much more powerful if it offers support for a variety of intelligences such as visual-spatial, bodily-kinesthetic, musical, interpersonal, intrapersonal, linguistic, and logical-mathematical - a projector can help to achieve this variety in a classroom. Data projectors can also be partnered with an interactive whiteboard to offer additional teaching strategies. A good data projector can show a large clear image that is visible from all parts of the classroom (note: very sunny rooms may require brighter projectors, special screens or some skylight or window treatment, textual content requires suitable font sizes and contrasting colours for easy reading).
3. Recent Advances:
The quality, brightness, features and ease of use of data projectors has improved significantly over the last few years. The size and weight have reduced significantly - better still so have the prices! It is now possible to get a really useful product for less than Australian $2000. On more advanced models additional features are provided such as auto focus, remote zoom, auto keystone correction, freeze, magnify, wide angle lens, picture-in-picture, etc. - these are typically available from Australian $3000 and higher.
Digital light processing (DLP) models may be better suited for projecting video while liquid crystal display (LCD) models may be better suited for projecting data. There can also be differences in brightness and longevity between DLP and LCD but different model projectors can use each technology to advantage.
4. Possible Uses:
Data projectors can be used in many locations (e.g. classrooms, conference rooms, lecture theatres, etc) - wherever there is a flat clear surface or screen that can be used to display the image.
- professional development of staff
- sharing or displaying of educational resources
- students presenting their work to a class
- as part of an interactive white board setup
- group participation in video conferencing, online or on screen tasks
- showing the words to the National Anthem, school songs, ...
- demonstrating new software
- viewing image intensive web sites suitable for class discussion
(e.g. digital photo galleries in photography lessons)
- magnify image from a digital microscope
- projecting live video of experiments, students receiving award at assemblies, ...
(so students or parents at the back can see what is happening more clearly)
- connecting to a smart board
- presentation of student work on parent nights
- display of interactive tours of world architecture with students
- teaching about contemporary internet art and art in general
- students will be able to show their films and animations full screen
- (please email suggestions to add to this list)
5. Buying Tips:
First make a list of your planned purposes (identify your priorities but think about future possibilities)
- are you looking for a unit to be fixed in the ceiling or mobile between classrooms?
- what size or mixture of rooms are involved? (e.g. halls, gymnasiums, classrooms, tutorial)
- how much light is in the rooms? (consider direction of sun, skylights, curtains, etc)
- what resolution computers are being used? (e.g. XGA)
After you have determined a shortlist
of possible models with features described below it is a good idea to
'test drive' the leading contender(s) - take along your laptop to the vendor
showroom and try it out for yourself. Do not let the vendor set it all up for
you - do all steps yourself so that you have a clear understanding of the ease
of use and suitability of a particular model.
Brightness - lamp brightness is critical in classrooms without curtains in sunny Australia. In general lamps that are rated more than 1000 ANSI lumens are recommended - however the price increases with the brightness so for particularly light rooms curtains may be cheaper. Consider fixed mounting on the ceiling for projectors over 2000 ANSI lumens to reduce the risk of intense light flashing on to the eyes of student or teachers.
Resolution - a desirable minimum standard is native 800 x 600 SVGA. Units may output higher or lower computer resolutions but the clearest picture is obtained when the data projector uses the native resolution of the PC. For computers with higher quality displays (e.g. 1024 x 768 XGA) a greater native resolution is required - however the price usually increases with the resolution.
Weight - less than 2.5 kg is ideal for easy mobility by either staff or students. A unit that can be easily shifted around the school will get much higher utilization rates and allow more equitable use by staff - however the price usually increases with reduced weight.
Size - units small enough to fit in laptop sized bags are very convenient but still require padding and careful handling - consider the best choice for your needs but remember that the price usually increases with reduced size.
Portability - ability for teachers or students to move the complete kit easily and safely.
Lamp life - look for at least 2000 hours rated lamp life. Also check the replacement lamp cost - typically $300-$600.
Noise levels - choose a unit that will operate quietly in a classroom so that the teacher and students can still converse without hearing difficulty due to the noise of the cooling fan - a desirable level is below 40 db.
Keystone correction - provides for perfectly square images (rather than sloping sides) - this is important if the projector will placed on a desk and angled up to project on a wall or screen
Maximum projected image size - particularly for larger rooms check that the data projector is able to display the full image size required from the floor or ceiling mounting positions that are accessible.
Heat - try to avoid units that run very hot. They require greater care and longer to cool down before being safe to move to the next class.
Leads - ensure that all necessary leads are included (e.g. cables for laptop to projector, AV, speakers, USB), it is helpful to label each lead (e.g. projector, audio, mouse).
Speakers - most data projectors have a basic internal speaker but for best quality stereo or surround sound (e.g. for playback of a DVD movie) check there is an option to connect external speakers.
Zoom feature - convenient way to reduce or enlarge the image size (without needing to move the projector closer or further from the screen).
Wireless remote control - great for presenter freedom - can control the projector from different parts of the room (including while in the audience), can include options such as magnify, blank screen, menu, laser pointer, etc.
Travel bag- essential to protect the data projector and hold all necessary leads and accessories, a rigid case with thick padding is also usually available if greater protection is required.
Warranty - a minimum of 2 years is recommended.
Video output - TV, Video, DVD compatible, PAL/NTSC/SECAM, option for S-video
Permanent ceiling mounting - check that there is an option to flip the image if the projector is best mounted 'upside down' on the ceiling.
Inbuilt Storage - some models can accept memory cards, flash drives or CDs for loading or storing a presentation without the use of a computer.
Sliding lens doors - useful as it avoids the protective lens cap being lost.
Training - some vendors may offer free on site training to get you started.
A sample list of quote requirements is shown below, please modify to suit your
o Easy to set up and use
o At least 1500 ANSI lumens*
(* NOTE: more powerful projectors may need to be ceiling mounted to avoid harmful eye contact)
o Automatic signal detection
o Long lamp life
o Compatible with interactive whiteboards
o Reliable equipment (e.g. for a remote school)
o Extended warranty
o Hard case for transportation
o Multiple Input & output options
o Weigh less than 3kg
o Laptop size
o Remote control
o XGA resolution
o All necessary leads
o Stock available now
o Laser pointer in remote
o Remote with cursor control and zoom
o Speaker options
o Low noise
o Ceiling mount kit and pole
o Fixed screens
o Backup loan unit
o Security cage + lock
* NOTE: When evaluating quotes for comparability ensure that all brightness figures are in ANSI lumens
6. Operating Tips:
- know your audience
(via earlier research, prior chats, observation or asking questions during the presentation)
- structure your content for learning: outline aims and outcomes
- make it interesting: less learning happens if the presentation is boring!
- be visual (use images, audio and video - not just text - see http://www.zardec.net.au/keith/visual.htm)
- respect your viewers: limit the amount of text and do not read out every point!
- use contrasting colours that display well via projector (some colour combinations on a computer project poorly)
- keep it large and clear (avoid fine print, cluttered screens, complex layout)
- speak effectively using variety in tone, speed and timing
- include pauses (for benefit of audience, for effect or to sip some water to avoid a dry mouth)
Health & Safety
- remind students not to look directly into the bright beam
- consider fixed mounting on the ceiling for projectors over 2000 ANSI lumens to reduce the risk of intense light flashing on to the eyes of student or teachers
- warn students not to touch hot surfaces on the projector (typically near the lamp)
- warn all users not to block the cooling fan on the data projector
- do not block the light beam close to the data projector (it is very hot, can melt plastic and may start a fire)
- keep any flammable objects well clear of the data projector
- CHECK your computer works with your projector BEFORE the presentation!
(e.g. you may need to change your screen resolution, adjust leads or volume for sound, your graphics card may be incompatible with a particular projector)
- treat data projectors with great care, avoid any jolts - lamps are expensive
- avoid using screws to hold leads in place (another presenter may need to switch lead to their laptop, leads can get snagged - better for a lead to come undone than pull a laptop or projector off the table)
- be aware that lamps typically lose brightness with age
- consider light coloured painted areas on walls (robust, allows large image sizes)
- folding portable screens with tripod bases can be used when traveling
- permanent screens need to be securely mounted with easy access for shorter people
- have a warning message or marker to avoid screens being pulled down too far (may not retract)
- check that the screen is not in any glare (from lights or sunshine) for all audience positions
- set the projector to maximum image size (if a zoom feature is available)
- move the projector until the image just fills the screen
- focus the image (use onscreen text for greater focusing accuracy)
- carry an extension cord and 4 outlet powerboard with the projector
- consider a Health and Safety approved laser pointer for indicating particular parts of a presentation
- label all cables clearly so that it is easy to set up the data projector
- (please email me any suggestions to add to this list)
7. Security Tips:
As data projectors are expensive they are a target for theft - it is unwise to have them visible through windows after hours. Any projectors permanently mounted below the ceiling should have a security attachment or a locked steel bracket to prevent unauthorized removal. It is desirable that permanent installations are in a room with monitored security sensors. All portable units should be placed in a secure store at the end of every teaching day (not just put away on the weekend). Alternatively portable units can be fitted with a lockable security attachment.
ANSI lumens: American National Standards Institute method for measuring brightness
keystone: angle of projection produces trapezoidal images (has sloping sides, not square)
pixels: abbreviation of picture element (picture made up of thousands of tiny rectangular pixels)
SVGA: medium resolution - 800 x 600 pixels
XGA: high resolution - 1024 x 768 pixels
Links to more detailed glossary sites :-
9. Helpful Resources: ***
recommended resources (more stars is better)
** The data projector in the classroom http://www.kented.org.uk/ngfl/teaching/projectors.html
(please email suggestions to add to this list)
*** Projector Central http://www.projectorcentral.com/buyers_guide.cfm
** Projector advice for first time buyer http://www.presentingsolutions.com/projectoradvice.asp
** Purchasing ideas and glossary http://www.projected.co.uk/lcd_data_projecter.htm
10. Site Credits: This site is to help the 80% of people who just want learning, information and communication technology to be easy to use and reliable. I believe the cheaper brighter data projectors now available provide an incredible opportunity for students. Feedback from Thierry Lehembre, David Krieg, Bryn Jones, Andrew Bennett and Annette Holman has been included on this site. Please take the trouble to offer ideas or suggestions - you will be acknowledged and others can benefit. This site is intended to be free of bias and receives no commercial gain from any party. Currently up to 200 people per week visit this site. Statistics on usage of this site were gathered by ozlog software. First published online in Feb 2003 - last revision date is shown at the top of this screen.
(hyperlinks are checked and this information is updated regularly based on feedback, published articles, new experience, Internet research and new models)
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