Note: Descriptions are shown in the official language in which they were submitted.
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FIELD 0l` TilE INVENTION
The presont invention rolates to camoras for telev~sion
surveillance, for ex~mple for security purposes. Such c~moras are
mounted at n Yantnge point, such aq on A ceilin~, from which
survelllance zone may be seon.
DESCRIPTION OF THE P~IOR ART
A known ~qystem of this type provides a camers with pan~ tilt
and zoom mechanisms. However~ the camera and its orientation may be
seen by persons in the surveillance zone~ who are thus able to judye
whether they are within its field of view.
A known alternative arrangement provides a camera obscured in
a suqpended housing~ which carries a number of dummy lenses and one
operative camera lens~ all of which look alike. The camera is fixed
within the housing, and views through the operative lens. The housing
may rotate to pan the camera but the camera cannot tilt. An example oS
such a system is disclosed in U.S. Patent No. 3~535~442 issued to
John E. Jennings~ 20th October 1970.
This arrangement gives to persons in the surveillance zone the
appearance of apparatus providing all-round camera vision~ and may
therefore deter them from crime, even although the camera actually
views in only one direction at a time.
It is desirable to provide a visible and crime-deterrent housing
with a camera which is able to range even more freely so aq to cover a
greater surveillance zone~ but which is such that persons in the
surveillance zone cannot detect that they are not in the field of view
of the camera. This cannot be achieved with known systems quch as that
of the Jennings Patent where the camera is forced to look along a
single direction relative to the housing. Another problem with known
systems is the difficulty of achieving zoom operation when the camera
views through a lens mounted on the housing and forming a fiYed front
element of the camera lens.
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SU~ARY 01~ THE INVF~TION
According to the present invention, thcre i8 providod
~urveillance app~ratus comprlsin~ a camera concealed within a housing
wh$ch carries oxternally a plurality of elements having thc appear~nce
of viewinU lenses. A piece of trim on the housing forms a viewin~
window for the camera, and means are concealed within the housin~ for
adjusting~ under remote control, the viewing axis of the camera to
look through different regions of the window.
Also according to the invention there may be a plurality of
piece~ of trim on a camera housing which are of like appearance and of
which at least one forms a viewing window for the camera. The or each
piece of trim may be a vertically extending strip, the adjusting means
tilting thc camera behind the window, for viewing at any elevation
within a predetermined range~ elevation being used herein to encompass
tilts above and below the horizontal.
The invention thus makes use of the decorative trim~ which
externally has no functional appearance~ to give the camera an extended
viewing window in place of the single direction viewing aperture of
the prior art lens arrangements. However~ dummy lenses are still
preferably used to draw attention away from the real viewing windows
provided by the trim.
The camera i~ also preferably mounted so that it can pan.
For this purpose the housing and the camera may rotate together about
a vertical axis so that the camera lens remain~ at the window~ or the
housing may be fixed~ a plurality of windows may be provided therein~
and the camera may pan from one window to another. The addition of the
tilt facility to the known pan facility gives complete coverage of the
whole region below and around the camera housing~ a facility which has
previou~ly only been available with systems using non-concealed
cameras.
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107~905
Tho camera m~y ~1JO r0ad~1y be ~rovlded with a remote
controlled zoom lens sillce tho camcra vlews through ~ wlndow~ rather
thAn a len~ on the housing forming an element of tha camera objcctive.
The housing m~y be cub~tantially hemispherical with cusved
Btrips of trim extendin~ over its surface from it~ periphery to its
centre. So that the camera ob~ective lens or its orientation shall not
be distinguishod from outYide the housin~, the camera, it3 lens mount,
parts within the houqing and the inside surface of the housing are
preferably all matt black. The trim is preferably very shiny~ a9 may
be the whole of the outside of the housing. Even so it may be possible
for the careful observer to detect the camera lens through the window
and dummy camera lenses may be provided within the housing~ to mislead
observers in the ~urveillance zone~ especially if more than one strip
of trim is a window.
BRIEF DESCnIPTION OF THE DRAWINGS
Figure 1 i~ an oblique view of a housing from below~ and
Figbre 2 is an oblique view of the housing ~rom above, showing
a camera and other parts.
DETAILED DESCRIPTION
A subYtantially hemispherical housing 10 carries on its outside
- a number of dummy lenses 12. Curved strips of trim 14 (Figure 1) are
fixed to the housings one of these strips covers a slot 16 (Figure 2).
Inside the housing 10 i~ mounted a television camera lô, having a zoom
objective lens 20. The camera is pivoted in a cradle about a horizontal
a~is 21 between bracket~ 22 which are attached to the rim of the housing
10. Across the top of the housing extends a bridge 24~ having a vertical
pivot 26 to which is connected a mounting 28.
Geared electric motors 30~ 32, 34 are provided to pan the
camera by rotating the housin~ 10 about the pivot 26~ to tilt the camera
3 about the axi~ 21, and to zoom the lens 20. These motors are controlled
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ln open loop, ~nd limlt ~wltchos aro provided in a manner known
~er se to stop or rcver~e oach motor at either limit of it~ tr~vel.
The surfaces of all parts within the housing cxcept the lens
20 are black so that they are dlfficult to see throu~h the window
from outside the housing. The strips of trim are made from a clear~
glossy, acrylic plnstics material. The portions of the surfnce of the
housing 10 behind those ~trips of trim which are not over the slot 16
are black, 80 that the strips all appear alike.
In use, the camera may zoom, tilt about the horizontal axi~
21, and pan about the vertical pivot 26. The objective lens 20
remain~ opposite the slot 16 so that the camera view is uninterrupted.
Persons in the surveillance zone may think the camera 18 views through
one or more of the dummy lenses 12, wherea~ in fact it ~iews through
one of the strips 14. Because all the ~trips look alike and the
parts within the housing cannot be seen from outside ~ince they are
black~ personq in the surveillance zone cannot observe the orientation
of the camera 18.
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