Note: Descriptions are shown in the official language in which they were submitted.
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Device for Displaying Alphanumeric Symbols
and/or Graphic Symbols
The present invention relates to a device for
displaying alphalphanumeric :symbols and/or graphic symbols as
defined in the preamble to Patent Claim 1.
Devices used for d~_splaying alphalphanumeric symbols
and/or graphics symbols have been described in the literature on
numerous occasions, and. have been used in practice. Examples of
such devices are displays of different sizes, with rows and
columns of light emitting diodes (LED's) that are arranged in the
form of a matrix.
A display device oi= this particular kind is disclosed,
for example, in internaationa=L patent application PCT/R095/00013.
This particular device incorporates a series of LED's or groups
of LED's on a suitably configured carrier, on which they are
aligned vertically; this carrier rotates at a constant rotational
o speed in excess of 1200 rpm <~bout the vertical axis of a drive
motor. The block circuit diagram contains, amongst other things,
a sequence generator for genE~rating the code sequences for the
symbols and graphic symbols, and a synchronizing circuit to
determine the precise angular position of the rotating LED
carrier, from which the actu<31 rotational speed of the LED
carrier is determined and re<~ulated.
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The rotating LED array is located inside a rotationally
symmetrical housing that is of acrylic plastic or a similar
transparent material. A static image or a readable sequence of
symbols and or graphic symbo7_s that is either stationary or moves
i in the manner of light writing is projected onto the surface of
the housing so that an observer can read it through an angular
range of more than 270°.
Proper triggering of the LED's, particularly with
reference to the speed of rogation of the LED array, is critical
for generating sequences of :symbols and/or graphic symbols that
can be easily read by an observer.
It is the task of t:he present invention to create a
device of the type described in the introduction hereto, which
uses a technically simple and, in particular, wear-free assembly
i for transferring energy onto the rotating element or the rotating
array.
This has been. done with the features set out in Claim
1. Advantageous configurations and development of the present
invention are the object of t:he secondary claims.
The measures according to the present invention that
relate to a non-contact. energy transmission system create such a
system that is free of any sort of wear; on the one hand, this
ensures that it is mair~tenan<:e free and, on the other hand, it
ensures that the quality of t:he overall display device is
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enhanced, despite the reducedl number of components and its simple
construction.
In one advantageous; configuration of this solution,
inductive transfer of energy is proposed as the non-contact
method of energy transfer. In a first alternative, a rotor is
provided, the ends of the coils or windings of which are
connected electrically to the circuit board or to electrical or
electrical components. A stator that is formed in two halves is
arranged around this rotor. 7,he rotor has at least one winding.
By rotating the rotor together with the drive shaft, current is
generated in the coil ~~y the outer magnet halves, and this is
supplied to the rotating elecaronic structural group (circuit
board).
It is advantageous that the stator or the halves of the
i stator be formed as per~maneni~ magnets. It is also advantageous to
provide the rotor with six coil packets, the longitudinal axes of
which are oriented radi.ally, in order to generate a three-phase
system, which is more favourable from the standpoint of
efficiency and smoothing the alternating current.
In a second alternative, there are torroidal coils on
the circuit board and fixed on the motor output side so as to be
spaced slightly apart ~~nd opposite each other: these serve to
induce and transfer electrical energy when the circuit board is
rotated.
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In one development of the present invention, the device
incorporates a PC interface and/or an infra-red interface for
purposes of data transfer for control and programming. The infra-
red interface permits the input of a desired sequence of symbols
and/or graphic symbols by way of a remote-control system..
Various embod.iment:~ of the present invention are
described in greater deaail below using the drawings appended
hereto. These drawings show i=ollowing:
Figure 1: the principles of t=he display device, in cross section
along the axis of rotation of the arrangement;
Figure 2: a section of the non-contact energy transfer system at
enlarged scale, indicated by the circle II in Figure 1;
Figure 3: a cross section through the embodiment shown in Figure
s 3 on the line IV-IV in Figure 3;
Figure 4: an alternative to i~he embodiment shown in Figure 3, in
a similar cross-secaion on the line IV-IV in Figure
Figure 5: another embodiment of the non-contact energy transfers
system in a ~;implified cross section.
Figure 1 shouts a preferred embodiment of the LED
display device according to i~he present invention in cross
section along the axis of roi~ation 21 of the array. An electric
motor 2 is mounted on a column, pedestal, or similar mounting or
5 supporting device 1; this moi~or is designed to provide a suitable
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speed, for example, from approximately 1000 to 3000 rpm,
preferably from approximately 2000 to 3000 rpm. A synchronous
motor is usually used as the electric motor 2 although, of
course, other motors can be used to the extent that they are
s suitable for the intended purpose.
A coupler 3 is secured to the drive shaft 20 of the
electric motor 2 in order to couple a printed circuit board 4 to
the electric motor 2 so as to ensure that it rotates with the
drive shaft 20. The printed circuit board 4 is mounted on this
coupler 3 or on the output side of the coupler 3 so as to be
oriented at an angle of approximately 90° to the axis of rotation
21 of the drive shaft 20. Tht~ circuit board 4 contains the
complete electronic circuitry for controlling the display device.
Essentially, this includes the triggering circuits for the LED's
6 or LED groups 6 by way of a source of regulated direct current,
a non-volatile memory for the alphalphanumeric symbols and/or
graphic symbols, and a symbol generator to convert the sequence
of symbols or graphic ~~ymbol:~ into the appropriate LED triggering
commands.
> The electronic pi:inted circuit board 4 also serves as a
mechanical mounting for' a carrier 5 that is arranged in the
preferred manner to be at approximately right angles to the
printed circuit board 4., i.e., more or less parallel to the axis
of rotation 21. At lea~~t one preferably vertical row of LED's or
i group of LED's 6 is attached to the carrier so as to extend
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radially outward, i.e.) so a;s to be essentially perpendicular to
the drive shaft 20 or axis o:f rotation 21.
The LED's 6 on the carrier 5 are coloured light-
emitting diodes in specific ~~olours and colour sequences. ; LED's
of constantly changing colours as well as LED's of the same
colour can be used. The selection of the colour depends
essentially on the type of display that is planned. The
application is, of course, not restricted to one row of sixteen
LED's 6. Depending on t:he particular abdication, the row can
contain more or fewer hED's 6.
The control system on the printed circuit board 4
ensures that that the desired LED's 6 light up in a pre-
determined time sequence in accordance with a stored program. In
general, the type of font (bold, cursive, etc.) and the transit
5 speed of the symbols and or graphic symbols is fixed, and the
user can only select a desired sequence of symbols and/or graphic
symbols, which is then input. However, by using a more costly and
flexible programming tool, the type of font, transit time, or
other parameters of thE~ sequence of symbols and/or graphic
o symbols that is to be displayed can be selected by the user as
desired.
In addition i.o controlling the device by way of a
computer 28 with infra--red activation 27, the above-described
device can also, as an alternative, be activated directly by
s means of an infra-red remote control system 29. The infra-red
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sensors 30 is mounted on a'rotating part such as, for example,
the carrier 5 or on the printed circuit board 4, in such a way
that it rotates with it. If the infra-red sensor 30 is installed
on a rotating part, this entails the advantage that data can be
i transferred to the so-called spherical display from all
directions using the remote-control system.
In principle, the frequency range used for transferring
data with a remote control system 29 is not restricted to the
infra-red range, although it is used here because it is used in
commercially available remote control systems.
Since, as a rule, unlike the computer 28, the remote
control system 29 does not have a screen or other display
elements in order to check the data that has been input, in the
case of data transfer using t;he remote control system 29, the
i display device itself with it:s LED's 6 serves as a display for
checking the data input.
Because of the high speed of the drive shaft 20 of
the electric motor 2, which is, for example, approximately 3000
rpm, a "stationary" image wit=h an image repetition frequency of
approximately 50 Hertz is generated for a person viewing the
display device. Depending on the predetermined and programmed
memory contents, this image c:an be a fixed or a moving text image
made up of alphanumeric: symbols, or it may be a graphic image.
Naturally, combination~> of such symbols and images are also
possible.
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In order to achieve a greater reading angle for an
individual who is viewing the display device, the LED heads 6 can
be inclined, it being preferred that such an inclination be
vertical. In addition, SMD LED's can be used as an alternative.
A flexible spring ;steel rod 7 is secured to the side of
the printed circuit board 4 that is opposite the LED carrier 5.
If so desired, there can be a weight 8 on the unattached face of
the spring steel rod 7, it being preferred that this weight 8 be
displaceable longitudinally on said spring steel rod 7. This
provides for optimal balancing that is matched to both the
construction of the device arid to operating conditions.
In place of the spring steel rod 7, i.t is also possible
to use a rod that is of anpther material that has comparable
properties, the elastic: deformability of the rod being an
essential material characteristic. In addition, instead of the
spring steel rod 7, it is possible to select a rod that can be
folded once or several times,, or released; it is also possible
to use a telescoping rod that. automatically deploys to its
operating length during' rotation, as a result of centrifugal
force.
As the arrangement begins to rotate about the axis
of rotation 21, because of the increasing centrifugal force, the
spring steel rod 7 or the equivalent rod element aligns itself to
a horizontal or almost horizontal position or to a position that
is on a line extended through the printed circuit board and thus,
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when in the operating position, stabilizes and balances the
device. The counterweight 8 that is attached to the end of the
spring steel rod 7 forms a counterweight for the LED array 5, 6
that is used. The entire display device thus stands securely,
i without the need for special, additional attachment to abase.
The use of a flexible, folding, or telescoping
balancing element 7 in place of a rigid, mechanical, balance body
entails the advantage of simpler assembly, in particular assembly
of the complete device in a housing 31 with small access
openings.
The entire arrangement, as described above, together
with its components, is usua7_ly installed in an enclosed housing
31. The housing 31 is essentially a spherical, cylindrical, or
other rotationally symmetrical housing. The spherical body 31 is
i of a transparent material, for example, acrylic glass, plastic,
glass, or the like. A preferred spherical body 31 that is used
has a diameter of approximatE~ly 30 cm and, in contrast to this,
has much smaller access; openings through which the above-
described arrangement i.s introduced into the housing 31. The
U housing 31 is then supported on the base or pedestal 1 on which
the electric motor 2 i~~ mounted.
In principle, the ~~rinted circuit board 4 could also be
mounted outside the housing :31. In this case, the electrical
triggering commands would be sent directly to the LED's 6 by way
of the electrical connections 32. However, arrangement of the
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printed circuit board 4 within the housing 31 is a preferred
construction since all the elements can be accommodated
completely within the r~ousinc~ 31, and the LED displayed device
forms a self-contained struci~ural unit. The housing 31 also
protects the printed circuit board 4 against dirt and other
injurious environmental. factors.
The electric motor 2 is connected by a supply cable to
the power supply by a supply cable that is routed through the
base 1, so the system c:an be supplied with the required
electrical energy when the system is switched on.
As is shown in Figure 2 to Figure 6, the induction
principle is used to provide for the non-contact transfer of
electrical energy to the printed circuit board. This version
exploits the fact that a voltage is generated (induced) in an
i electrical conductor ii. the magnetic flux is varied over time by
a surface that is enclosed'by this electrical conductor. Thus,
when the circuit is closed, a current flows without the need for
a voltage source within the ~~ircuit. The voltage is generated
according to specific oequir~ements:
U
- if the electrica=l conductor is so moved within a magnetic
field that it int<~rsects the lines of force of this field;
- if the electrical conductor is kept stationary and the
magnet is moved;
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- if the electrical conductor and the magnet are kept
stationary but the magnetic field is changed;
- if the electrical conductor and the magnet remain at rest
when the magnetic field is fixed, and a substance with
another relative permeability is introduced into the
magnetic field;
- if the electrical conductor is curved.
In all of the cases set out above, a voltage is induced by
changing the magnetic i=lux over time.
Figure 2 shows an examp:Le of the non-contact transfer of
energy diagrammatically. The electric motor 2 is connected to a
power source through the supply cable 10 and drives the printed
circuit board 4 with the LED's or groups of LED's 6 by way of the
drive shaft 20. At the same 'time, a rotor 14 with a coil 15 is
> caused to rotate. A f_Lxed stator 16 that is formed from two
halves 17 is installed around the rotor 14, as can be clearly
seen from the cross-section chown in Figure 3. The stator can be
connected to either a DC or an AC power source, or it can also be
a permanent magnet. The two lhalves 17 of the stator 16 are
> arranged with their facie ends 18 spaced apart by the distance 19,
so that there is an air gap left between them. The winding
endings 13 of the coil l2 indicate an electrical connection to
the printed circuit board 4, which is caused to rotate by the
drive shaft 20. The coal 12 can be provided with an iron core or
i a soft iron core (not :shown herein). In order to protect the coil
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12 against the effects of weather, it can be embedded, at least
partially, in sealing c:ompound.
In place of the t:wo ha:Lf sections 17, a number of sections
can be arranged in a cp_rcle around the rotor 14. The number of
sections 17, which is always an even number, is calculated
according to the formu7_a n . 1/2, with n being an integer.
In this case, the fixed stator 16 consists of a permanent
magnet 34 that is surrounded by an iron shell 35. The rotor 14,
which rotates with the drive shaft 20 of the electric motor 2,
has six coil forms 32 a rrangc=_d in a ring, the longitudinal axes
of these coils being arranged radially so that the face ends of
the coil forms 32 are wore o:r less parallel to and opposite the
permanent magnet 34. In order to increase the induction effect,
the six coil forms 32 are each the provided with an iron core or
soft iron core 33, the cross section of which is advantageously
the anchor shape shown in Figure 4. The winding ends of the
coil forms 32 are connected to the printed circuit board 4 or the
electronic components on the printed circuit board 4, as
described heretofore.
Finally, Figure 5 shows another alternative version in which
the electric motor 2 i~~ supp:Lied with electrical power through
the supply cable 10 anti cause=_s the printed circuit board 4 to
rotate by means of the drive shaft 20. A primary coil 23 with a
magnet core or coil core 24 (iron core, soft iron core) is
arranged beneath the printed circuit board 4 so as to leave a
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small air gap 22 of up to 2 mm wide: the longitudinal axes of the
coils are oriented at the approximately right angles to the
printed circuit board 4. A :secondary coil 25 beneath the printed
circuit board is directly opposite this primary coil 23.so_that
the two face ends of the coils 23 and 25 are approximately
parallel to each other. A coil core 26 of this secondary coil can
be let into the underside of the printed circuit board 4.
However, the secondary coil 25 can also be attached to the
underside of the printed circuit board 4 or the applied by
layering technique.
The inductive transfer of energy using this alternative is
effected by having electrica7~ energy from the primary circuit
(primary coil) act on the secondary coil.
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