[Ultra-small Projectors Teardown] Playing with Images [Part 0]

Dec 25, 2008
Nikkei Electronics Teardown Squad
Fig1: I finally had this image projected on my back using the PK101. This is the moment when my dream came true.
Fig1: I finally had this image projected on my back using the PK101. This is the moment when my dream came true.
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Fig 2: The PK101 (left) and the MPro110 (right)
Fig 2: The PK101 (left) and the MPro110 (right)
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Fig 3: The PK101 was projecting the upper image from a digital camera, and the MPro110 was projecting the lower image from a notebook PC.
Fig 3: The PK101 was projecting the upper image from a digital camera, and the MPro110 was projecting the lower image from a notebook PC.
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Fig 4: A PowerPoint image projected by the Mpro110
Fig 4: A PowerPoint image projected by the Mpro110
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"You are good! I'm getting exited!" I feel a bit stronger because of the mark on my back (Fig 1).

Well, I got carried away. I have long wanted to buy an ultra-small projector and play with it by projecting images on my clothes. I took a picture of a fan and projected it on my shirt.

Oops, I have no time to play. I have to start breaking down the projector as soon as I check its image quality. So, we went ahead and project an image in a dark room.

We purchased the "MPro110" manufactured by 3M Co of the US and the "Optoma pocket projector PK101" of Optoma Corp of Taiwan.

In respect of the appearance, the MPro110 looks like a miniature version of an existing stationary projector (Fig 2). Also, its composite input and 15-pin VGA connection remind me of an existing projector.

The PK101 resembles a portable AV device. It incorporates a speaker for audio output. Meanwhile, the MPro110 cannot output audio signals, and its composite terminal is the only image input terminal it has. The black-based body color makes it look cool.

We connected each of the two projectors with a digital camera via a composite cable to directly project images on a white wall. The MPro110 has both a video input and a 15-pin VGA connector; therefore, we connected it to a notebook PC, too, by using a VGA cable.

People in our news room, including myself, made the following comments after using the ultra-small projectors.

- For both projectors, images were clear when viewed in a dark room. Perhaps, the images projected by the PK101 were slightly clearer (Fig 3).

- For both projectors, the image focus can be adjusted manually by turning a dial on the body. Even if the focus is properly adjusted, the images are slightly blurred every time they are switched, requiring fine adjustments for each image.

- It was easier to adjust the focus with the PK101 than with the MPro110.

- As for the MPro110, no difference was observed between digital camera images projected via the video terminal and the same images projected via a VGA cable connected to a notebook PC.

- When a PowerPoint document stored in a notebook PC was projected, small letters were hard to read (Fig 4). After the image was properly focused, however, they were readable.

- When in operation, the projectors are warm to the touch. The MPro110 was a little warmer than human body temperature, while the PK101 was as warm as body temperature. The MPro110 felt warmer perhaps because of the vent holes for letting out warm air.

We also asked comments from an engineer who has a good knowledge of projectors and participated in the teardown. He watched some images in a dim room*and commented as follows.

*The lights were turned off and window shades were pulled down to cut off the daylight. Still, it was difficult to make the room completely dark due to the light coming in from the windows.

- The images projected by the MPro110 "look cold" because it uses white LEDs as a light source, making it difficult to produce warm colors. White LEDs usually incorporate blue LED chips and fluorescent substances to create the white color, and, therefore, are not suited for producing red and green colors. In particular, the red color is often weak.

- In respect to the MPro110, the dial for focus adjustment is not easy to use. Judging from the range of focus, this projector seems to be intended for short-distance projection.

- The PK101 uses an RGB (red, green and blue) LEDs as its power source and provides clear, deep-color images.

- The gradation sequence is limited in both projectors. The PK101 seems to have a gradation of 4 to 5 bits. It employs DMD as display element. Some stationary projectors that incorporate DMD have gradations of about 9 bits.

One reporter said the PK101 will be a better choice for three reasons. It is "smaller," "looks cool" and "provides more beautiful images." He was planning to project images on the ceiling and view them while lying on the floor. He asked me, "How much are they?" When I said, "They are around ¥50,000 (approx US$541) each," he suddenly became silent. It looks like they are a little expensive for him.