Casio's LED-Hybrid Projectors

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The trouble with projectors is that their mercury lamps burn out after 2,000 to 5,000 hours and cost hundreds of dollars to replace. Casio has a better idea—projectors that incorporate a hybrid light source comprised of LEDs and lasers and a novel way to mix primary colors. The result is the Green Slim line of DLP-based models that run for 20,000 hours—illumination for the life of the projector.

All of the projectors in the Green Slim (rhymes not with the pejorative slime but with the affable Tim) line look identical except for an extra input or two on some models. Since each projector is merely 1.7-inches in height and occupies an 11.7- x 8.3-inch footprint hardly larger than a sheet of paper, you could slip one into the same carrying case you'd normally use for a notebook computer. At 5 pounds, the Green Slim (think SlimJim) weighs less than many notebooks. You may not even need to bring along the computer. That's because some models accept your entire presentation on a USB stick. These projectors are made for traveling light.

Moreover, several of these models are Wi-Fi-enabled for streaming your presentation simultaneously to audience members' computers. As the crowd leans into their private screens, there shouldn't be a bad view in the house.

What makes each projector so special is the hybrid light engine. In lieu of a conventional lamp, Casio combines red LEDs and blue lasers along with green phosphors on half a wheel. (The other half is clear.) The blue laser passes through the clear part of the wheel but excites green phosphors on the other half. The primary colors of light come together. (See illustrations below.) A Digital Light Processor smaller than a postage stamp contains a matrix of hinged micro mirrors that pivot to compose a complete image that's reflected into the lens. The 2X optical zoom lens can project an image as large as 300 inches. All the projectors in the series can be ceiling mounted or used with a rear-projection screen. All have at least HDMI and VGA inputs. They each have a built-in 1-watt mono speaker and come with a remote and batteries.

Why It's Called A "Hybrid" Light Source

Light from red LED strikes micro mirrors (rectangle upper left).

Blue laser passes through clear portion of spinning wheel.

Laser excites green phosphors on other half of wheel.

Since the light engine is the same across the Green Slim line, the models differ in other ways. Some have a native XGA resolution of 1024 x 768 pixels, producing a conventional 4:3 aspect ratio, while others a WXGA resolution of 1280 x 800, producing a widescreen 16:10 image. Both types can show high-definition video (since the minimum requirement is 720 lines) but neither natively delivers Full HD. (That's why there's scaling.) Three of the models turn out 2000 Lumens of brightness, while four turn it up to 2500 Lumens. The higher number improves visibility when an image is enlarged or must compete with more ambient light than is ideal. All the models feature a contrast ratio of 1800:1.

Things get interesting when you compare how the presentation enters the projector. The basic models are meant for use with either a VGA or HDMI cable connected to a source component like a computer or DVD player alongside. Models that are USB host-enabled, on the other hand, allow you to play PowerPoint presentations saved to a USB storage device directly. (Casio provides software to convert the presentation in your computer before saving to a thumb drive, for instance.) You can also attach a Casio camera for showing content stored in the camera.

The same USB port can be used in a different way. Instead of playing content, the input can accept a USB wireless presentation adapter for simulcasting the show to multiple computers wirelessly through the room's Wi-Fi network. Casio provides software that must be installed on each computer, but the result is sharing your big picture with as many as 32 smaller screens. The Casio Wireless Presentation Adapter is bundled with one model and offered as an optional accessory with two others. See chart below.

Casio's Collection of Green Slim Projectors

Model

Resolution

Brightness in Lumens

USB Host

Wireless LAN

XJ-A140

1024 x 768

 2500

No

No

XJ-A240

1280 x 800

 2500

No

No

XJ-A235U

1280 x 800

 2000

Yes

Option

XJ-A135U

1024 x 768

 2000

Yes

Option

XJ-A230

1280 x 800

 2000

No

No

XJ-A245VIJ

1280 x 800

 2500

Yes

Yes