Electronic dissuasive device for birds

The device comprises a housing featuring a transparent window behind which is positioned an infrared detector. A disc in the same plane as that of the front face of the housing can rotate around its central axis perpendicular to said plane. The visible side of the disc shows a pattern of a color in contrast with that of the disc, such as black over white background or vice-versa. If the infrared detector signals the presence of a heat-emitting source, such as the one given out by the body of a bird on a surface to be protected, a dissuasive process for birds is activated which combines disc rotation and sound emission. The disc rotation creates the illusion of the presence of the eye of a bird of prey, while the sound emission includes cries like those of birds in distress, or cries or a feared bird of prey.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a device for dissuading birds from 
alighting on certain surfaces, and more particularly to a device that 
includes a rotating image for frightening the birds. 
2. Description of the Prior Art 
It is well known that birds often try to alight on the outer structures of 
buildings, such as window sashes, sills, ledges, statues, wall ridges, 
roof gutters, portals, bridges, towers and masts. 
This alighting and resting is a nuisance in that the birds, through their 
droppings, dirty and damage not only the landing surface, but also all 
outer structures of the building that are underneath. 
Due to aesthetic reasons, and also to avoid irreversible damaging of the 
structure material, one is often obliged to deal with frequent and 
expensive renovation work of the damaged parts of the building. 
One of the most efficient ways of preventing this nuisance consists in 
covering surfaces on which birds alighting is not welcome, with a device 
comprising a bottom base support from which extend upwardly birds 
dissuasive spike elements. Such a device is described in European patent 
application number 0 340 108, published on Nov. 2, 1989. 
Such a device, however, is not fit for larger surfaces because of cost. 
Additionally, for obvious reasons, such devices are not suitable for 
surfaces utilized by people, such as balconies. For those surfaces, other 
systems have been developed which work on the principle of either 
simulating an object which frightens the bird, such as a human-like 
silhouette ("scarecrow effect), or of emitting a signal (e.g. ultrasound 
or hyperfrequency) which is physiologically bothersome to the birds. The 
drawbacks of the latter system are particularly the development cost, the 
difficulty in calibrating a really bothering signal, and the nuisance 
induced for men and domestic animals next to the protected surfaces. 
Another drawback of both systems is that they only bother the birds which 
progressively get used to them, rendering the protection inefficient 
sooner or later. 
SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to disclose a device 
having none of the above-mentioned drawbacks. The device according to the 
present invention, comprises a housing having a transparent window behind 
which is positioned an infrared detector. A disc in the same plane as that 
of a front face of the housing can rotate around its central axis 
perpendicular to said plane. The visible side of the disc shows a pattern 
of a color in contrast with that of the disc, such as black over white 
background, or vice-versa. If the infrared detector signals the presence 
of a heat-emitting source, such as the one given out by the body of a bird 
on a surface to be protected, a dissuasive process for birds is activated 
which combines disc rotation and sound emission. 
The disc rotation creates the illusion of the presence of the eye of a bird 
of prey, by utilizing concentric rings which vary in color (for example 
white, grey, black, etc.), radius and intensity according to the rotation 
speed. 
The sound emission includes cries, such as of birds in distress, or cries 
of a feared bird of prey. 
One fully efficient and inexpensive embodiment of the invention does not 
comprise the sound emission: the dissuasive effect consists only in the 
illusion of the eye of a bird of prey by rotation of the disc. 
More particularly, the present invention comprises a dissuasive device for 
birds comprising a frame, a mobile part susceptible of being rotated by 
reference to the frame, and showing a pattern simulating the eye of a bird 
of prey when the mobile part is rotating, a system locked to the frame, 
for rotating the mobile part, an electrical power supply, means for 
detecting the presence of birds, and means for activating the rotating 
system at a first frequency and for a first duration, when the presence of 
a bird is detected.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 is a perspective view of an electronic dissuasive device for birds. 
The electronic dissuasive device is composed of a housing 12, cast or 
otherwise assembled according to any known technique for ensuring 
watertightness and protection for inner electrical and mechanical 
elements. 
The housing features a transparent window 13 behind which is positioned an 
infrared detector 35 described with respect to FIG. 3. The housing also 
features an opening 14 in front of an inner loudspeaker 38 (shown in FIG. 
3). The latter opening can be omitted if the embodiment of the invention 
does not include the loudspeaker 38, as explained below. A disc 10 in the 
same plane as that of the front face of the housing can rotate around its 
central axis perpendicular to said plane. The visible side of the disc 
shows a pattern 11 of a color in contrast with that of the disc, such as 
black over a white background, or vice-versa. 
The shape of the pattern 11 (a coma) shown in FIG. 1 is merely 
illustrative. Other shapes for the pattern 11 could also result in the 
desired effect of simulating the eye of a bird of prey in motion. For 
example, by the use of concentric rings, the color (e.g. white, grey, 
black), the radius and the intensity of which vary according to the 
rotation speed. Shape, dimensions and colors of the housing are not 
critical, and can be those of a cube having edges of 15 cm, and a color 
identical to that of the disc. 
The housing is equipped with feet or any other fixing system (not shown) so 
as to allow steady positioning of the dissuasive device next to the 
surface to be protected, or for hanging onto a wall, a tree branch, etc. 
FIG. 2 is a cross-sectional view taken along the line A--A of FIG. 1. The 
housing 12 features a frame 22, which is bound to it. The housing 12 and 
frame 22 may be formed from a single piece out of a cast, or be assembled 
together, according to any known technique. A motor 21 is fastened to the 
frame, as well as a printed circuit 23 on which are placed the electronic 
components of the device, and a battery 24. Electrical connections between 
the above elements are not shown. It will be obvious to one skilled in the 
art that the disclosed arrangement of elements is not decisive. The motor 
21 has an axis 20 allowing to rotate the disc. 
In the preferred embodiment, a battery (rechargeable battery or not) is 
utilized as the source of energy. However, any other source allowing 
autonomous functioning of the device, such as that provided by small solar 
panels according to known techniques, may also be used. When the source of 
energy is that of the house power, the device is not autonomous anymore, 
but this type of functioning is also covered by the present invention 
because one skilled in the art knows how to convert AC high voltage into 
DC low voltage so as to provide power to the electronic components of the 
device. 
FIG. 3 is an electronic functional schematic of the present invention. 
Chosen components can preferably be the circuits having as reference 1710X 
for IC1, and 775X for IC2, available from the "NEC" (trademark) Company. 
Details of implementing and functioning of these circuits are therefore 
fully accessible to one skilled in the art. 
IC1 is a microcontroller 30 capable of executing a sequence of instructions 
corresponding to the process explained below. It features inputs I0 to I5 
and BUSY, and outputs D0 and D1, as well as CS, ST, RESET, and 39. The 
power-on information is conveyed through a resistor 33. The 
microcontroller 30 has an oscillator and capacitors between its inputs X1 
and X2 following a well-known technique (for example at a frequency of 640 
kHz). An on input I4 is available for the amplified and rectified output 
signal of a known infrared detector 35. An on input I5 is available for 
the amplified and rectified output signal of a daylight detector 36. The 
latter detector, not shown on FIG. 1 or FIG. 2, is placed on one of the 
upper faces of the housing. Four switches 32 allow the microcontroller 30 
to be programmed (one combination amongst 16) through I0 to I3. Output 39 
allows a signal, after amplification, to command rotation of motor 21. 
IC2 is a sound synthesizer 31, capable of generating (depending on command 
circuit 30) a choice of prerecorded sounds. The prerecorded sounds are 
recorded using a system, available for example from the "NEC" Company, 
that allows digitalization, signal compression and programming of IC2 
following techniques well-known to one skilled in the art. IC2 features 
outputs BUSY and AVO, and inputs D0 to D7, as well as CS, ST, RESET. 
The power-on information is conveyed through lead RESET activated by 
microcontroller 30. Sound synthesizer 31 has an oscillator and capacitors 
between its inputs X1 and X2 (for example at a frequency of 640 kHz). 
Inputs D2 to D7 are grounded as non utilized. Output AVO connected to 
electrical power through resistor 34, allows activating a loud-speaker 38, 
through a low-pass filter 37 and after amplification. 
All electronic components of the present device are powered by the battery 
24 and a voltage regulator (not shown). 
The functioning of the electronic schematic will further be explained with 
FIG. 4. The latter figure represents the functional process associated 
with the electronic schematic of the present invention. First step 40 
consists in a reset to zero of the various internal counters of circuits 
30 and 31. This step is processed at power-on of the device, when the 
battery is replaced, or when a switch (not shown) accessible from the 
outside of the housing, and imbedded in the power supply circuitry, is 
activated. A second step 41, consists for circuit 30 in reading the 
programmed word on its inputs I0 to I3: the latter word will determine the 
choice of one dissuasive process amongst 16 as is discussed below. 
Next step 42 consists in making sure that input I5 is active, i.e. that 
functioning of the device is required when, in daylight only, birds can 
show up and it is intended to dissuade them from alighting on certain 
surfaces. As soon as I5 becomes active, circuit 30 checks at step 43 
whether the infrared detector has signaled, by activating I4, the presence 
of a heat source such as the one provided by the body of a bird on the 
surface to be protected. As soon as it is signalled, the proper dissuasive 
process itself starts at step 44. 
The dissuasive process consists in one amongst 16 alternatives, combining 
various durations (circuit 30 features internal timers) and frequencies of 
command of the motor by lead 39, and of durations and choices of one 
prerecorded sound amongst 4 through leads D0 and D1, CS and ST. Variations 
in the frequency of the command of the motor result in variations of disc 
rotation speed, so as to bring about the illusion of the dynamic of an eye 
in motion. One prerecorded sound can be, for example, the cry of a bird in 
distress, or that of a feared bird of prey. Switches 32 allow choice of 
which amongst the dissuasive possibilities, can be accessible to a user of 
the device who looks for the alternative dissuasive process working best 
against the kind of bird he wants to get rid of. It will be obvious to one 
skilled in the art that the given number of switches (4) is purely 
indicative, and governs the number of dissuasive alternatives. 
Superimposing random generation can also be effective in that the birds do 
not get accustomed to the device. 
One fully efficient and inexpensive embodiment of the invention does not 
include the circuit 31, nor filter 37 or loud-speaker 38. In this 
alternative embodiment, the dissuasive effect consists only in the 
illusion of the eye of a bird of prey by rotation of the disc. The 
daylight detector 36 can also be omitted. 
In another embodiment, the disc is replaced by a system opening out under 
centrifugal force when in rotation, also showing a pattern 11, which 
contributes even more to the dynamic of the illusion. 
Although the present invention has been described in terms of the presently 
preferred embodiment, it is to be understood that such disclosure is not 
to be interpreted as limiting. Various alterations and modifications will 
no doubt become apparent to those skilled in the art after having read the 
above disclosure. Accordingly, it is intended that the appended claims be 
interpreted as covering all alterations and modifications as fall within 
the true spirit and scope of the invention.