The most significant advance in video technology during
the 1980s was the invention and introduction of the
solid-state video camera. By the early 1990s the solid-state
camera using the charged coupled device (CCD) image
sensor was the choice for new security installations and
was rapidly replacing the tube cameras. In the past, the
camera—in particular, the vidicon tube sensor—was the
critical component in the video system. The camera determined
the overall performance and quality of visual intelligence
obtainable from the security system. The vidicon
tube was the weakest link in the system and was subject
to degradation with age and usage. The complexity
and variability of the image tube and its analog electrical
nature made it less reliable than the other solid-state
components. Performance varied considerably between
different camera models and camera manufacturers, and
as a function of temperature and age. By contrast, the
solid-state CCD sensor and newer metal oxide semiconductor
(MOS) and complimentary MOS (CMOS) sensor
cameras have long life and are stable over all operating
conditions. Another factor in the explosive use of video
in security systems has been the rapid improvement in
equipment capability at affordable prices. This has been
the result of the widespread use of solid-state camcorders
by consumers (lower manufacturing costs), and the availability
of low-cost video cassette recorders (VCRs), digital
video recorders (DVRs), and personal computer (PC)-
based equipment.