Note: Descriptions are shown in the official language in which they were submitted.
2072P,77
An Apparatus for Receiving and ~val~ating Optical
Signals
The invention relates to an apparatus for receiving and
evaluating optical signals, with a sansor for receiving
the optical signals ` and thair conversion into
electrical signals, a receiving part for processing the
electrical signals into data, ~nd a computer for
processing the data into representable and~cr
recordable and~or control-technieally usable
information, in a~cord~nce with the charateri~ing
clause of claim 1.
In the present connection `'optical'` refers to an
electromagnetic alternating field with a fre~uency in
the spectral range of the infrared, visible and/or
ultraviolet light. Optical signals comprise therefore
the intensity, frequency and/or impulse modulation of
light in the infrared, visible and/or ultraviolet
spectral range.
It is, ,or example, ~nown rrom WO-90/08501 to ma~e
information availa~le in form of coded digital values,
to transfer them as optical signals and to reconvert
the latter into coded digital values again in a
receiver and then supply them as electrical signals for
further processing. This processing can comprise a
graphic representation. From WO-90/08501 it is also
~nown that a light receiving unit for the optical
signals comprises a sensor as well as its feed and
output circuits, the sensor being disposed on a wall of
the cabinat of the light receivng unit.
Tt is ~no~n to process digital values in a computer in
order to represent or to record them in a tabular or
graphic manner, or in order to further use them as
2 2~7~`~ i 7
control-technical information, for example as control
commands (so-called computer control). It is
furthermore ~nown to apply a computer, for e~ample, of
the type ~nown today as PC ('`personal computer'`).
.n information received in the form of optical signals
therefore can, after its trans_ormaticn into electrical
si~nals, be supplied to a computer of the type PC or of
a similar Xind for further processin~.
It is of disadvant~ge here that the receiving part and
the computer are accommodated separately ~rom each
other in ~ifferent cabin~.s and ~ sicn~ls provided by
the recei~ing part must be supplied to the computer via
a cable.
It is furthermore of disadvantace that the receiving
part and the computer each need an own feed and the
corresponding cable for the connection to the
electrical mains~
Cabinet and cable and their connections form various
sources of disturbances. Cables are disturbing merely
because of their existence alone - it is not witnout
aood reason that the public ~pe_Xs of "cable salad" in
he vicinity of a PC.
If the combination of receiving part and computer is
provided for the application for medical purposes in a
hospital environment, as is the case for example with
the system ~nown from WO-90/0~50l, the safety of people
must furthermore meet legal regulations, e.g. it must
meet the S~iss SEV-standard ~P6,/d.
It is therefore the object of the invention to remove
the sources of disturbance ~ith the various cables and
cabinets in an apparatus c- ~he above-mentioned ~ind
3 2~72~ ~ ~
and this way to increase the safety of persons as well
as the operating comfort.
For solving this object an apparatus of the above-
mentioned kind is characterized by the combination of
the elements mentioned in claim 1. Advantageous
embodiments result from the depandent claims~
With the invention the advanta~e is achieved that the
entire receivng ~art and its connecticns are enclosad
in the computer and are ther~^ore inaccessible to the
personnel, s~ that the receivin~ part on the one hand
is not exposed to external ir.fluences and on the other
that the personnel is not en~angered~
Other ad~antages and details of the invention result
from the following description of examples of the
embodiment of the invention with reference to the
Figures.
ig. 1 shows an example of an arrangement of the
sensor at a wall of the cabinet of the
computer in the apparatus according to the
invention;
ig~ 2 shows an example of an embodiment of the
circuit of the receiving part in the
apparatus according to the invention~
In Fig. 1 a computer of, for example, the type
presently known as PC ("personal computer") is
diagramm~tically represented. The computer has a
cabinet 1, at the front wall 2 of which the front side
3 of a diskette unit 4 t"diskette drive") is visible.
The diskette unit 4 is intec~ated in the cabinet 1, the
front side 3 of the diskette unit 4 in the front w~ll 2
of the cabinet 1~ This integration is facilitated or
g 2~7~,~77
enabled in that today the dis~ette units are built in a
standard format in order to fit corresponding
standardized recesses which are provided in the
cabinet of the computers.
An apparatus in accordance with the invention for
receiving and evaluating optical signals comprises a
sensor for receiving these optical signals~ This sensor
is for example dispcsed as a ?hotodiode which converts
the received optic~l si~nals into electrical sign~ls~
~re, tha optical signals ~manatin~ from a suited
sender can be su~lied from ;his sender to the sensor
either directly via space or via a suited li~ht guide
as, for e~ample, a glass fiber~
In Fig. 1 such a sensor is re~erred to with ~ as first
example~ The sensor 5 is disposed at the front wall 2
of the cabinet 1 of the computer~
The apparatus in accordance with the invention also
comprises a receiving part for processing the
electrical signals to data which are supplied o the
computer in order to be processed therein to
representable and/or reco-d2ble and/or control-
technically applicable information.
In Fig. 1 such a receivng ~_rt is integrated in the
computer in such a manner hat the circuits of the
receiving part are located in the interior of the
cabinet 1 and are therefore not visible in Fig. 1,
while the sensors disposed cn the front wall 2 of the
cabinet 1 is mounted on a f-ont ?late 6 which forms a
wall of tha receiving part, lt belng integrated in the
front wall 2.
2~?72~ ~7
The sensor 5 can also be mounted directly on the front
wall 2 and be integrated in it.
Also, the sensor 5 can, for e~ample, be mounted on an
insert card which again is mounted in the computer or
in the cabinet 1 behind the front wall 2 in such a
manner that the sensor 5 project~ outwardly throuoh a
hole in tha ~ront wall 2.
In a variant of this embodiment the hole 'or the sensor
5 can be provided in the front pl~te ~ which a~ain is
integrate~ in the front wall 2. The front plate ~ can
be designed of a re!atively ~oft ~nd elastic material
li~e a rubber-liXe plastic ~n order to protect the
sensor.
In Fig~ 1 a sensor o~ the above-mentioned type is
referred to with 7 as sacond e~ample. The sensor 7 is
disposed on the front plate 8 of a receiving part. The
front plate 8 forms` a part of the cabinet of a
receiving part whose circuits are again located in the
interior of the cabinet 1 and are therefore not visible
in Fig. 1. The cabinet of the receiving part is
arranged as unit in standard format of a dis~ette unit
(`'diskette drive"). Hence, the cabin.et of the receiving
part fits into the cor-asponcingly standardized
recess of the cabinet 1 at a location which is
normally provided for the mounting of a dis~ette unit.
The front plata 8 of the receiving part is so designed
that it is integrated in the front wall 2 of the
cabinet 1 when the cabine~ of the receiving part is
mounted on the computer.
The sensor 7, for e~ample, can again be mounted on a
printed circuit board which again is mounted in the
computer or in the cabinet î behind tha front plate 8
at a location which is no~mally provided for the
6 2~72~77
mounting of a diskette unit. Here the sensor 7 projects
outwardly through a hole provided in the front plate 8
while the front plate S again is integrated in the
front wall ~. Batween the front plate S and the sensor
7 a bush of a relatively soft and elastic material, for
a~ample as a ru~bar~ e plastic, can be ~isposed for
protecting the sancor 7.
~enerally, the sensor ~ or ~ can just as ~ell be
mounted essen~iall~ in th~ plane of the front wall 2 or
~ha front plate S or prQ~act outwal-dly opposite of the
front wall ? or .he f~ont pla.e S, or ba displaced
inwardly still oppcsite of ~he front wall ~ or the
front plata ~. It is to be undarstood in this sense
that the sensor 5 or 7 is assantially disposad on or in
the proximity of the front wall ~ or the front plate 8.
The sensor 5 or 7 can also comprise an interface for a
suited light guide as, for e~:ample, a glass fiber. It
is then this interface to the light guide which can
essentially be mounted in the plane of the front wall 2
or the front plate 8 or projecting outwardly opposite
of the front wall 2 or the front plate 8 or displaced
in~aràly still opposite of the front wall 2 or the
front plate 8. 8uch a mounting is eauivalent to the
before-described mounting of the sensor 5 or 7, and in
this sense it is also to be understood that the sensor
5 or 7 is essentially disposad on or in the proximity
of the front wall 2 or the front plate 8.
In Fig. 2 an example of an embodiment of the circuit of
the receiving part is diagrammatically represented.
In Fig. 2 the sensor is -eferred to with 20 and
designed as a photodiode, its clamps being connected
with the pole of a voltage source S and with the other
clamp ~ith a resistor R. The other pole of the voltage
7 ~,n~? f 7
source S and the other clamp of the resistor R are
connected with the grounding line M of the circuit of
the receiving part. The sensor 20 receives a modulated
light L. The optical signals transmitted by the light L
are therefore converted into electrical signals by the
sensor 20.
The receiving part, which is represented in its
entirety in Fig. 2, comprises a first subcircuit 21, a
sacond subcircuit ~ and a third subcircuit ~3.
~he first _ubcircuit is d~termined for the processing
of the electrical signals of the sensor 20 to serially
tr~nsmitt~hle data~ It comprises as `lnput stage an
amplifier 24 the input 24a of which is fed the
electrical signals from sensor 20~ The sensor 20 is
designed as a PIN-type-diode and the amplifier 24 is
designed as a transimpedance amplifier in such a manner
as described, for example in the Hewlett-Packard
Journal, December 1988, pages 26-28. The output of the
amplifier 24 is conducted via a band-pass filter 25 and
supplied .o the next element 2~ of the first
subcircuit.
In the now àescribed e~em?lary embodiment of the
further elements of the first subcircuit it is supposed
that the optical signals transmitted by the light L and
hence the electrical signals supplied by the sensor 20
are modulated according to the method of the amplitude
shift ~eying~ Of course, other modulation methods as
for e~ample the frequency shift ~eying (FSK) are
applicable, in case of which the first subcircuit is
correspondingly designed~
For the processing of the FSK-modulated electrical
signals of the sensor 20 to cerially transmittable data
he signals are demoàulated according to the method of
2~72~7 `~
quasi-syncronous modulation. For this, the element 26
of the first subcircuit is an amplifier which is
provided with a control input which again is connected
to an AGC-circuit 27~ ~or re-obtaining the carrier
signal a high quality ~C-oscillation circuit 28 is
connected to an output of the amplifier ~ n output
of this LC-oscillation circuit 2~3 is connected to a
control input of the ~C-circuit ~7 via a limiter ~9
which closes the AGC-control circuit of the amplifier
2~
Furthermcre, at an output of the amplifier ~ one input
of a multi~lier 31 is connected via an ampli~ier 30,
while the other input of the multiplier 31 is connected
to an output of the limiter ~9~ ~he multiplier 31
supplies at its output a voltage which is proportional
to the product of the input voltace received from the
amplifier 30 with the carrier si~nal received from
limiter 29, for this purpose the multiplier 31 works
a~cording to the Gilbert-Ce.ll principle, such a
multiplier being, for example, described in the
National Semiconductor Linear Data Handbook, Volume 3,
pages 5 - 92 to ~ - q6~ The output signal of the
multiplier 31 is guided via a band-pass filter 32 and
supplied to a comparator 33 whose output supplies a
demodulated signal in a serially transmittable form
which is further transmitted to the second subcircuit
via the mutually connected lines 3~a and 3~b designed
for serial transmission.
The second subcircuit is determined for the
trans~ormation OI data which are serially transmitted
via the lines 34a and 34b to parallelly transmittable
data.
In the exemplary embodiment of the second subcircuit
now described it is supposed that the optical signals
9 2a7~g~
transmitted by light L and hence the electrical signals
supplied by the sensor 20 represent data which is coded
according to the ~nown FM-coding method. Other coding
methods are also applicable, of course, the second
subcircuit then having to be designed accordingly.
For the transformation of the serially transmitted data
to parallel txansmittable datz the line ~4b leads via
an input amplifier 35 to an FNO~-demodulatox with an
asynchronous counter 36 which is trig~ered by a clock
cenerator~ An output of the FM0-demodulator 3~ is
connected with the input of a p~otocol docodQr 38 in which
on the one hand the transmission protocol of ~h~ transmitted
~ata is attenuated and on the other a ~-digit channel
number is ganerated. The cata liberated from the
transmission protocol and the channel number are transferred-
in a serial/parallel transformer 39 to paralleltransmittable data which are transmitted via lines 40a
and 40b which are connected with one another and
designed for parallal transmission to the third
subcircuit.
~he third subcircuit is dètermined for the
transformation of the data which has been parallelly
transmitted via the lines 40a and 40b to data which are
usable for the computer.
For this the third subcircuit is designed as an
interrupt-controlled interface between a parallel data
input and a data output connectable to the bus of the
computer, and it comprises a correspondingly
controllable component part 1 znd an address-decoder
42 whose output is connected with a control input of
the componant part 41. ~urthermore, the output lines of
the component part 41 and the input lines of the
address-decoder A2 are compr_saà on a plug connector 43
which is designed for plugging in~o one of the plugging
20~72~r s~)
locations for printed circuit boards in the computer.
Such plugging locations for insert cards are ~nown in
the computers of the type PC ('`personal computer").
The output lines of the component part 41 and the input
lines of the address-decoder ~2 are therefore connected
to the bus of the computer wnen the plug connector 43
is plugged into one Qf tha plugging locations for
insert cards in the computer~ ~ compcnent part ~1
suitad therefor and an addre~s-decoder 42 suited
therefor are ~nown~
Plugging locations ~or inser; cards are also ~nown in
computers of the typ~ ~nown as PC ("parsonal
computer"), as well as corresponding constructions of
the component part 41 and the address-decoder 42 for
application in such computers~
In a first embodiment of the receiving part the first,
the second and the third subcircuit are arranged
together on a common printed circuit board of standard
format for the computer, for example, of the type PC.
In this embodiment the lines 34a and 34b are guided on
the insert cards and are directly connacted with èach
other, so that the serial output of the first
subcircuit is connected with the serial input of the
second subcircuit. In this embodiment the lines 40a and
40b are also auided on the insert cards and connected
directly with each other, so that the paralle~ output
of the second subcircuit is connected with the parallel
input of the third subcircuit.
The sensor 20 for its part is connected with an input
arranged on the insert card of the first subcircuit,
i.a., of the amplifier 24. n an exemplary embodiment
the sensor 20 can be mounte~ on the insert card and can
project outwardly through t~:e wall of the cabinet of
r!
the computer, for e~ample throuqh the front wall 2. In
another exemplary embodiment, in which the receiving
part has an own cabinet or at least an own front plate
8, the sensor ~0 can be mounted on the insert card and
project outwardly through the wall of the cabinet of
the receiving part, for example through the front plate
8.
In a second embodiment of the recei~ing part the first
subcircuit is disposed on a printed circuit board which
is mounted in the cabinet of ,he computer at a location
provided for a dis~ette station, while the second and
the third subcircuits are disposed toaether on an
insart card of stand~rd rormat for the computer, for
example, of the type ?C~ ~'ith this embodiment the lines
34a and 34b are connected with each other via lines
leading from the printed circuit board to the insert
card, so that the serial output of the first subcircuit
is connected with the serial input of the second
subcircuit. Oppositely thereof the lines 40a and 40b in
this embodiment are guided on the insert card and are
directly connected with each other, so that the
parallel output of the second subcircuit is connected
with the parallel input OI the third subcircuit.
In a third embodiment of tha receiving part the first
and the second subcircuits a_e arranaed together on a
printed circuit board which is mounted in the cabinet
of the computer at a location provided for a diskette
station, while the third subci~cuit is arranaed on an
insert card of standard for~lat for the computer, for
example, of the PC type. In this embodiment the lines
~4a and 34b are guided on the printed circuit board and
directly connected with each other, so that the serial
output of the first subcircuit is connected with the
serial input of the seccnd subcircuit. Oppositely
thereof the lines 40a and ~.0b in this embodiment are
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connected with each other via lines leading from the
printed circuit board to the insert card, ~o that the
parallel output of the second subcircuit is connected
with the parallel input of the third subcircuit~
The sensor 20 for its part is connected in the second
embodiment (w~ith the first subcircuit on a printed
circuit board and the second and third subcircuit
together on an insert card) as well as in the thir~
embodiment (with the first a~d second subcircuits
togethar on a printad circuit board and tha third
subcircuit on an insart card~ with an input disposed on
the printad circuit be~rd of ;he fir~t subcircuit, i~a~
the amplifier 24~ In an e~emplary embodiment the sensor
20 can ba mounted on tha printed circuit board and
project outwardly through the wall of the cabinet of
the computer, for exampla through tha front wall 2~ In
anothar e~emplary ambodiment, in which the receiving
part has an own cabinet or at least an own front plate
8, the sensor 20 can be mounted on the printed circuit
board and project outwardly through the wall of the
cabinet of the receiving part, for example through the
front plate 8~
It is to be under~tood that -or ~ne characteristics of
the apparatus according to tha invention there exist
many e~uivalent ambodiments, so that an expert could
embody the invention in numerous variants without
thereby laaving tha protecti~a cphere which is defined
in the claims~
