The TopHead TM150 is a two-in-one LCD display. You’ve heard of
picture-in-picture, but what about picture-on-picture? TopHead’s groundbreaking
monitor shoehorns two LCD panels into a single frame.
The primary display is a 15-inch, 1024 x 768 resolution screen. The upper,
secondary panel measures 6.4-inch diagonally, with a 640 x 480 image. Between
the ashy and bruised-purple casing and the protruding shiny rods and handles,
this two-screened beast looks more like a trade-show concept piece than an
actual product.
The TM150 connects to a dual-head video card (or a PC with two video cards)
via a custom split-VGA cable bonded to the back of the monitor—no DVI inputs
here. Both panels are plug-and-play, so you won’t need drivers for setup. The
smaller screen is ideal for videoconferencing or for specially designed
applications, such as an ID scanner with mug shot pop-up.
In addition to VGA, there is a composite video input port (although S-Video
would have been better). A signal from your video card isn’t restricted to one
of the panels, and video signals can be switched between the panels; either or
both LCD panels can show the video signal at the push of a button. The secondary
display works well as a TV, but it can be distracting, and the image is
cramped.
The 15-inch panel is respectable, with a 115-degree vertical and 140-degree
horizontal viewing angle, 24-bit color, and a 300:1 contrast ratio. The smaller
panel, unfortunately, is not nearly as good. It has a 100:1 contrast ratio,
18-bit color, and a mere 40-degree vertical and 80-degree horizontal viewing
angle.
We used DisplayMate Multimedia edition (available from www.displaymate.com)
to test the quality of the screens. The 15-inch panel performed almost
flawlessly, and fast-moving action did not smear. However, we noticed that the
frame appeared to bulge into the viewable area of the screen, obscuring part of
the top border of the panel. The LCD has no pincushion control in the onscreen
display, so we couldn’t fix the problem.
Despite its disappointingly shallow viewing angle, the 6.4-inch screen was
sharp, solid, and did not smear. However, it suffers from weak contrast, and
performed poorly on the timing/pixel lock tests, resulting in an unstable
picture for fine detail. We tried, and failed, to defeat the flicker with the
automatic adjustment controls.
Our biggest problem with the TM150 is that we couldn’t get the monitor in a
position where both screens looked good. To keep the top monitor from washing
out, we had to tilt the frame back unnaturally far, which made for a distracting
view of both screens. Even with its strengths, the TopHead is a risky buy unless
you have a specific use in mind for that second screen.
-- Jason Compton
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