Tag Archives: beamer

Trend 2018: LDT Beamer vs. LED Beamer vs. DLP Projector

Nowadays beamers re used not only for presentations, demonstrations and lessons, but also as handy “multi-talents” at home, for example, instead of a TV-set. These projectors are especially handy when showing a movie on a projection screen to a small group of people. Movie-night lovers can experience a real cinema feeling.

projektorenAt work or education facilities, the projectors are still used for reflecting a PC, notebook or another multimedia terminal device onto a large screen.

There are many various models and types ranging from functional high-performance stationary projectors up to mobile small gadgets for presentations or home-cinema systems.

DLP Beamer: Digital Light Processing

In the event of a DLP projector, a DMD (digital micro-mirror device) is used as an image converter. This is an integrated circuit that provides a tilting micro-mirror for each image point. The micro-mirrors are controlled by electrical pulses. The mirrors can only accept two states: ON or OFF.

Source: http://www.hcinema.de/farbrad.htm

Source: http://www.hcinema.de/farbrad.htm

For this kind of image formation, the brightness gradations can only be achieved by very fast switching-over of the tilting micro-mirrors.

The DMD device can project all three primary colours one by one, with the aid of a rapidly rotating colour wheel. Current DLP video projectors use six or seven colour segments in a single colour wheel. High-performance DLP projectors are still used in cinemas.

Advantages of the DLP beamers:

  • High speed
  • No after-glowing of the image
  • No burning-in of still images
  • Higher contrast than on an LCD beamer
  • Almost no pixel artefacts
  • Less sensitive to dust, because the optics is encapsulated

Disadvantages of the DLP beamers:

  • If the colour wheel does not run fast enough, it may be a rainbow effect
  • Individual colours might flicker
  • Higher noise emission by the colour wheel and fan
  • Optimal image resolution depends on the type of the installed mirror matrix

LED Beamer: Light Emitting Diode

In these video projectors, the image is still generated by a DLP element or, in newer models, by a LCD (Liquid Crystal Display). LEDs are used just as sources of light. In this type of beamers, the colours themselves are generated by a sequential flashing of each individual LED.

A LED beamer is an ideal solution for mobile use, for example, a visual support or illustration of a business speech. In this case, the light wave length is between 540 and 610 nanometres.

Advantages of the LED beamers:

  • Higher energy efficiency
  • Lighter construction, since active cooling is not a must
  • Due to the low energy consumption, it can also be operated with a battery
  • Noise emission is significantly lower, because there is one wheel less

Disadvantages of the LED beamers:

  • LCD as an imaging device can only achieve a satisfactory pictorial quality with a fixed resolution
  • The total light output is lower
  • In the case of luminous flux reduction, the image continuously darkens. This loss of brightness can only be compensated by adaptive increase of current
  • Rainbow effect, because the basic colours are projected one by one

LDT Beamers: Laser Display Technology

Laser beamers initiate formation of images by a laser beam rapidly deflected and modulated. With a LTD beamer, the image is written on the large screen line by line.


Source: https://www.professional-system.de/basics/laser-beamer-mit-laser-in-die-zukunft/

As a result, the projector achieves a much better image quality. A special scanner with a facet mirror provides for formation of lines, whereas the tiling mirror initiates the next line feed.

The modulated laser beam can determine the correct brightness and colour for each image point. Appropriate security mechanisms ensure a trouble-free operation, so that the operator is not afraid of the laser.

Advantages of the LDT beamers:

  • Large contrast range
  • High light output is possible
  • Long service life of the light source
  • Basic colours are mixed to an overall image

Disadvantages of the LDT beamers:

  • High purchase price
  • In the case of high performance laser projectors, there is a danger for eyes without personal protection equipment
  • Speckle patterns may occur

We recommend different beamers and technologies, depending on the type or place of use.You can hardly find a beamer suitable for each situation and at each location.

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Beamer vs. Whiteboards in the training room – Part 2

Now it’s time for the second part of the “Royal battle”.

In one corner there is the long-established projector, in the other our upstart, the touch screen with integrated whiteboard software or connected Android Whiteboard Box. The previous result is 2: 2 or a draw for projectors and whiteboards in the areas of installation, image size and contrast and quality. You missed the first game? Here you can retrace the battle.

beamer vs touchscreen

In order to detain you no longer: “Let’s get ready to rumble!”

Round 3: Interactivity

With digital whiteboards as well as with interactive beamers, professors, teachers or students can write directly onto the picture. In addition, both of them often provide sophisticated software for creating, displaying and storing teaching contributions, such as the Whiteboard software from InFocus. The difference shows when the screen is to be touched in order to select a program. Here, whiteboards work with digital pens as well as with the powerful multi-touch technology which allows you to write on the display with several fingers at the same time. In this regard, the projectors cannot match.




Winners: Whiteboards

Round 4: Shadows

No matter how much you try to avoid, beamers cast shadows when people enter their projection field. And there are only a few things that are more disagreeable during a presentation than to be blinded by the light of the projector or not to be able to see a complete picture due to the shadows. Whiteboards create the image internally by using liquid crystal display panels. Thus, there is no shadowing. In addition, they are independent of light conditions and provide a clear picture even in strong sunlight.




Winners: Whiteboards

Round 5: Costs

With regard to technology for the education sector, often the price is crucial. Projectors are the undefeated champions on the cost side. For example, a 65-inch JTouch is fast three times as expensive as a Short ThrowBeamer. Depending on the model, the Whiteboard software or Android Whiteboard Box has also to be added in the case of the JTouch. Although a lamp has to be bought and replaced every two years, the projectors remain cheaper.




Winners: projectors



After the judges have scored their points, a clear winner is determined:

the whiteboards.


However, the Beamers demand a rematch. The beamer technology is maturing and prices are falling. This point of the beamers might be lost this time. We will see. Notwithstanding the above: the ultimate winners of projection technology are neither whiteboards nor projectors, but teachers and students.

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