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Re: Solid state cameras (fwd)



---------- Forwarded message ----------
Date: Thu, 06 Aug 1998 00:12:30 EDT
From: th3 mAst3r <menthol-at-juno-dot-com>
To: tesla-at-pupman-dot-com
Subject: Re: Solid state cameras (fwd)


On Wed, 5 Aug 1998 20:50:15 -0600 (MDT) Tesla List <tesla-at-pupman-dot-com>
writes:
>
>
>---------- Forwarded message ----------
>Date: Wed, 5 Aug 98 11:03:04 EDT
>From: Gary Lau  05-Aug-1998 1044 <lau-at-hdecad.ENET.dec-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Solid state cameras
>
>I'm contemplating the purchase of a solid state still-image camera, to 
>be
>used largely in documenting the construction and operation of my coil.
>I've seen videos of TC operation that are plagued by snowy 
>interference,
>and I'm wondering if solid state CCD imagers are simply a bad idea
>anywhere near operating coils.  Has anyone used one sucessfully with
>near-photographic quality?
>
>Also, do current models permit extended (multi-second "B" mode) 
>exposures?
>
>Gary Lau
>Waltham, MA USA
>
>

the article below is one that may be of interest to you.  apparently
these new cameras do not use ccd technology.  if the interference caused
by TCs was affecting the ccd portion of the camera (and not the cmos
processing portion), this would be an ideal solution.  i have no idea how
well a normal ccd camera would work... could work fine for all i know but
thought you might be interested in this....

~m3nthol



[article obtained from http://www.questlink-dot-com]

Bell Labs Licenses 'Camera on a chip' Technology

----------------------------------------------------------------------------
----

MURRAY HILL, N.J. (July 15, 1998) -- The idea of having video cameras the
size of a marble came one step closer to reality today with the
announcement
that Bell Labs has licensed its high-performance "camera on a chip"
technology to Vanguard International Semiconductor Corporation.


(The picture at right is also available as a full-resolution TIFF file
[1.8
MBytes].)

Bell Labs technology is ideal for PC videoconferencing and security
cameras
because each camera will use a single quarter-inch silicon chip.

The "camera on a chip" approach, based on the same CMOS (complementary
metal
oxide semiconductor) technology found in today's computer chips, produces
real-time video images that rival the quality of images produced by
camcorders, which rely on a handful of non-CMOS chips.

"While other companies have tried to use a single CMOS chip in video
cameras, we're the first group to show high-quality performance," said
researcher Bryan Ackland of Bell Labs, which is the research and
development
arm of Lucent Technologies.

'Active pixtel' technology
The key to the CMOS camera's high performance is how Bell Labs
researchers
improved upon state-of-the-art "active pixel" technology, and this
expertise
complements Vanguard's ability to produce low-cost silicon chips. "We see
an
opportunity in CMOS technology, and we're fortunate to have Lucent as our
partner," said Bob Swartz, director of Vanguard's Imager Product business
unit.

Third-party camera and computer peripheral manufacturers will package the
Vanguard chips with a small lens, and the final camera eventually will
sell
for less than $50, Swartz said.

By developing a high-quality imaging array using conventional CMOS
technology, the researchers integrated all of the functions normally
associated with a camera -- timing and control, analog-to-digital
conversion, and the signal processing required to provide exposure
control
and color balance -- onto a single silicon chip.

Traditonally, video cameras have required more chips because the camera
relies on a specialized imaging process, known as CCD (charge-coupled
device) technology -- which also was developed at Bell Labs in 1969. It
turns out that the CCD manufacturing process is not well suited for
making
the different types of transistors necessary for the various non-image
capturing functions.

100,000 optical sensors
The imaging array on the current Bell Labs chip is comprised of more than
100,000 optical sensors (or pixels) laid out in a two-dimensional grid on
the silicon surface. Each pixel generates a small packet of charge when
illuminated by an image. Individual pixels are accessed using a
two-dimensional arrangement of address and data buses, which is similar
to
how semiconductor memories are accessed. A small amplifier at each pixel
helps reduce noise and distortion levels.

"Although the 'active pixel' approach was first proposed back in the
early
70s," said Marc Loinaz, a researcher at Bell Labs, "it's only been in the
last few years that technology has progressed enough to where transistors
can be included in each pixel without significantly increasing the size
of
the array."

Conquering 'fixed pattern noise' problem
Even with this change, however, CMOS-based cameras have been plagued by a
defect known as "fixed pattern noise." This is an annoying stationary
background pattern in the image that results from small differences in
the
behavior of the individual pixel amplifiers. Although some believed this
defect would prevent CMOS from ever seriously challenging CCDs, the Bell
Labs researchers developed circuits outside the sensor array that detect
and
cancel this noise.

Besides requiring less space, CMOS cameras use less power than CCD
cameras.
A nine-volt battery, for instance, powers a CMOS camera for five hours,
but
powers one of today's computer-based desktop cameras for only 30 minutes.
As
a result, CMOS cameras are well suited for hand-held cameras or security
cameras.

The CMOS camera also allows users to immediately access specific portions
of
an image. With today's video camera, users first must produce the entire
image before manipulating it.

Uses are many-fold
Although the new technology initially will be used for computer and
security
cameras, future uses might include three-dimensional imaging and
collision
avoidance, such as cameras detecting other vehicles in a car's blind
spot.
The camera also might become integrated into computer screens.

"This camera might follow the same life-cycle as the digital clock,"
Ackland
says, "which used to be an expensive stand-alone device, but is virtually
everywhere now."

Because the camera on a chip is an offshoot of today's silicon-chip
technology, any semiconductor manufacturer could produce the chip at
existing facilities, Ackland said. The same situation has not existed
with
CCD technology, which requires specially designed manufacturing
facilities.

Lucent Technologies, headquartered in Murray Hill, N.J., designs, builds
and
delivers a wide range of public and private networks, communications
systems
and software, data networking systems, business telephone systems and
microelectronic components. Bell Labs is the research and development arm
of
Lucent Technologies. For more information on Lucent Technologies, visit
the
company's web site at <http://www.lucent-dot-com>.

Vanguard International Semiconductor Corporation (VIS), with headquarters
in
the Science-Based Industrial Park, Hsinchu, Taiwan, designs, develops,
manufactures, markets and sells DRAM and other semiconductor products.
VIS
has its own in-house design expertise, supplemented by a strong US design
subsidiary in San Jose, California. VIS sells its products through its US
sales office, as well as a worldwide network of distributors and
representatives. More information is available at
<http://www.vis-dot-com.tw>.





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