U.S. patent number 3,885,408 [Application Number 05/410,397] was granted by the patent office on 1975-05-27 for finger operated electro-optical lock and method.
Invention is credited to Charles T. Clark, Jr..
United States Patent |
3,885,408 |
Clark, Jr. |
May 27, 1975 |
Finger operated electro-optical lock and method
Abstract
A finger operated electro-optical lock system in which an
optical keyboard having at least one zone indicated thereon is
illuminated by ambient energy until touched by a finger of the
human hand blocking the radiant energy passing through the zone. A
counter is thus enabled to cycle a numeric display. When the first
digit of the combination appears in the display, the finger is
lifted and reapplied until the second digit of the combination is
displayed. The process is repeated until each digit of the
combination has been displayed.
Inventors: |
Clark, Jr.; Charles T.
(Lighthouse Point, FL) |
Family
ID: |
23624542 |
Appl.
No.: |
05/410,397 |
Filed: |
October 29, 1973 |
Current U.S.
Class: |
70/278.1;
250/221; 361/172; 70/DIG.51; 361/176 |
Current CPC
Class: |
E05B
49/006 (20130101); G07C 9/33 (20200101); Y10T
70/7068 (20150401); Y10S 70/51 (20130101) |
Current International
Class: |
E05B
49/00 (20060101); G07C 9/00 (20060101); E05b
049/00 () |
Field of
Search: |
;70/278,DIG.51
;250/209,221 ;317/124,134 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Craig, Jr.; Albert G.
Attorney, Agent or Firm: Burns, Doane, Swecker &
Mathis
Claims
What is claimed is:
1. A lock system for an enclosure entrance comprising:
manually operable electro-optical switch means internal of the
enclosure;
pulse means responsive to said switch means for providing a series
of pulses at a predetermined repetition rate;
display means for providing a visual indicia internal of the
enclosure related to the number of pulses provided by said pulse
means, said display means being positioned for viewing by the
operator of said switch means external of the enclosure so that the
operation of said switch means may be selectively terminated to
effect the display of predetermined visual indicia by said display
means to the operator external of the enclosure;
lock means; and,
circuit means internal of the enclosure and responsive to the
effecting of the display of predetermined visual indicia by said
pulse means for effecting the operation of said lock means.
2. The system of claim 1 wherein said manually operable switch
means includes:
a sheet of radiant energy pervious material;
a pair of detectors on the side of said sheet internal of the
enclosure, each of said pair of detectors being responsive to
ambient radiant energy passing through a predetermined zone on said
sheet from the other side thereof; and,
circuit means responsive to an imbalance in the ambient radiant
energy detected by said pair of detectors for effecting the
operation of said switch means.
3. The system of claim 2 wherein said circuit means includes means
for inhibiting the operation of said lock means in the event that
the visual indicia display effected by said pulse means is other
than predetermined indicia.
4. The system of claim 1 wherein said circuit means includes means
for inhibiting the operation of said lock means in the event that
the visual indicia display effected by said pulse means is other
than predetermined indicia.
5. An electro-optical locking system for an enclosure entrance
comprising:
a sheet of radiant energy pervious material carried by the
enclosure and providing structural integrity for the enclosure;
a pair of detectors on the side of said sheet internal of the
enclosure, each of said pair of detectors being responsive to
radiant energy passed through a predetermined zone on said
sheet;
a lock; and,
means internal of the enclosure responsive to a predetermined
sequence of the durations of a plurality of time intervals each
related to an imbalance in the radiant energy detected by said pair
of detectors for effecting the operation of said lock, said lock
operating means including:
switch means for establishing a desired sequence of time interval
duration,
counter means advanced in response to each imbalance in the radiant
energy detected by said pair of detectors to a value related to the
duration of the imbalance, and
circuit means for effecting the operation of said lock for a
predetermined time interval in response to the sequential
advancement of said counter means to each of a predetermined
plurality of values, said circuit means being reset in response to
the termination of advance at a value other than said predetermined
plurality of values and in response to the termination of advance
at one of said predetermined plurality of values in other than a
predetermined sequence.
6. A system for operating the lock of an enclosure entrance
comprising:
a sheet of radiation transparent material carried by the enclosure
and providing structural integrity for the enclosure;
a plurality of radiation responsive elements on the side of said
sheet internal of the enclosure, each of said elements being
associated with a predetermined zone of said sheet;
switch means on the side of said sheet internal of the enclosure
operable in response to a modification of the radiation of said
elements from the side of said sheet external of said
enclosure;
display means;
means responsive to the duration of the operation of said switch
means for modifying the indicia displayed by said display means and
for providing a unique signal related to the duration of the
operation of said switch means responsively to the termination of
the operation of said switch means; and,
means for evaluating said unique signal and for effecting the
operation of the enclosure lock in response to a favorable
evaluation.
7. The system of claim 6 wherein said switch means is operable from
a position external of the enclosure by the positioning of the
finger of a human hand in a predetermined position on said sheet of
radiation transparent material.
8. The system of claim 7 wherein said lock operating means
includes:
switch means for establishing a desired sequence unique signal
provision.
9. The system of claim 8 wherein said sheet of material is glass
having a thickness of at least about one-quarter inch.
10. A method for operating the locking device of the entrance to an
enclosure without compromising the integrity of the enclosure
comprising the steps of:
a. sequentially modifying for a plurality of time intervals the
passage of radiant energy from a source external of the enclosure
through a predetermined zone of a sheet of structural material
optically transparent to the radiant energy;
b. detecting internally of the enclosure the duration of each of
the time intervals during which the passage of radiant energy is
modified;
c. evaluating the sequence of time interval duration detection with
respect to a predetermined sequence; and,
d. operating the locking device responsively to the evaluation of
the time interval duration sequence evaluation.
Description
BACKGROUND OF THE INVENTION
The present invention relates to an optical keying system and more
particularly to an electro-optical system for operating a locking
mechanism from a point externally of a building to which entry is
desired.
Electronic combination locking systems in which a series of
switches are set in a predetermined combination in order to release
a locking mechanism are well known. The combination indicating
devices for these sytstems are generally mechanically actuated
switches which are subject to mechanical wear. Moreover, many of
the electronic locking systems operate on the principle of
selecting a predetermined combination by simultaneously positioning
switches corresponding to the predetermined combination. These
systems have the disadvantage that the requirement of simultaneous
actuation or setting of the switches to the predetermined
combination may offer an observer a view of the combination before
it is possible to move the switches away from their combination
indicating positions.
The use of electromagnetic and optical scanners to read a card or
other "key" inserted into a slot is generally known and may be
found, for example, in the operation of parking lot closures. All
systems of this type suffer from the disadvantage that the slot
into which the key must be placed may be obstructed by leaves,
twigs, dirt and the like by children and by vandals. In addition,
the "combination" of such systems have not been readily
modifiable.
It is accordingly an object of the present invention to obtain the
deficiency of these known systems and to provide a novel and
improved electro-optical locking system and method in which a
single optical key is actuated for predetermined periods of time
for operating a locking mechanism.
It is another object of this invention to provide a novel system
and method in which the "combination" of the mechanism may be
easily and quickly manually modified.
It is yet another object of the invention to provide a novel
circuit and method for evaluating a predeterminned sequence of
optically controlled time intervals.
It is yet another object of the present invention to provide a
novel system and method for operating a lock in which all of the
operable parts thereof are located internally of the structure into
which entry is desired.
It is still another object of the present invention to provide a
novel optical keyboard actuated by the presence of the human finger
at a preselected zone on the board for predetermined time
intervals.
These and many other objects and advantages of the present
invention will be readily apparent to one skilled in the art to
which the invention pertains from the claims and from the perusal
of the following detailed description in connection with the
appended drawings.
THE DRAWINGS
FIG. 1 is a functional block diagram of the system of the present
invention;
FIG. 2 is a pictorial view in elevation of the optical keyboard of
the system of FIG. 1;
FIG. 3 is a section taken through the optical keyboard of FIG. 2;
and,
FIG. 4 is a schematic circuit diagram of the logic circuit of FIG.
1.
THE DETAILED DESCRIPTION
With reference now to FIG. 1 where the system of the present
invention is displayed in block diagram form, a switch 10 is
manually operated to enable or to unblock an oscillator 12 which in
turn applies pulses to a counter 14. The number of pulses applied
to the counter may be decoded in a decoder 16 and displayed in a
display 18.
The switch 10 may be of any suitable conventional type but
desirably is of the type hereinafter illustrated and described in
detail. The oscillator 12 may be of the type illustrated in the
circuit of FIG. 4 but may also comprise any suitable conventional
pulse generating circuit. It is desirable, but not necessary, that
the pulses provided by the oscillator 12 be of a uniform pulse
repetition rate. The counter 14 which receives the pulses from the
oscillator 12 may be of any suitable conventional type such as a
ring counter to continually increment in response to pulse
application. Thus, the operation of the switch 10 enables the
oscillator 12 to cycle the counter 14 and to increment the digit
displayed by the display 18.
The operation of the switch 10 may also enable a timing circuit
which resets the counter 14 and enables the driver decoder circuit
16. In this manner, the operation of the switch 10 may effect the
initial reset of the counter 14 and enable the driver decoder
circuit 16 so that the number of pulses provided by the oscillator
12 subsequent to the operation of the switch 10 will be indicated
to the switch operator at the display 18. The display 18 will thus
continually cycle until the switch 10 is disabled at which time the
oscillator 12 will cease to increment the counter 14 and the last
pulse digit indication will remain in the display 18. The timing
circuit 26 may be operative after a predetermined time delay such
as ten seconds to reset the counter 14 and disable the drive
decoder circuit 16 to remove the digit indication from the display
18.
With continued reference to FIG. 1, the driver decoder circuit may
provide input signals to a decoder circuit 20. These input signals
will, of course, reflect the digit indicated at the display 18. The
decoder 20 may be operative to transform the binary coded decimal
contents of the counter 14 to decimal form. The disabling of the
switch 10 may, through the timing circuit 26, effect the reading of
the digit stored within the decoder 20 into a logic circuit 22 for
evaluation purposes.
The operation of the logic circuit 22 in response to a selected
combination is hereinafter discussed in greater detail in
connection with FIG. 4. In the embodiment illustrated, the three
digits of the combination are the numerals 1, 7 and 9 and
appropriate output terminals from the decoder 20 are connected to
the logic circuit 22. The remaining output terminals 0, 2-6 and 8
are desirably connected together and to the logic circuit 22. The
logic circuit 22 is thus operative to effect resetting of the
circuit upon receipt of a single digit signal not in the
predetermined combination. In addition, the logic circuit 22 may be
operative to reset the circuit in the event that the digit signals
are not received in the appropriate predetermnined sequence. The
sequential receipt of the digits 1, 7 and 9 in the desired order by
the logic circuit 22 will effect the operation of the lock 24 for a
predetermined time interval as determined by the timing circuit 26
earlier described.
The operation of the embodiment illustrated in the figures will now
briefly be announced. The individual desiring access to the
interior of an enclosure such as an apartment house or the like
will approach the locking mechanism from the exterior of the
building and operate the switch 10 by placing a finger over an
indicated zone in a plate glass window. The placing of the finger
over the appropriate zone will reduce the ambient light at that
particular zone which will reset the counter 14 through the timing
circuit 26 to enable or unblock the oscillator 12 to continually
increment the counter 14 until such time as the finger is removed
from the switch.
With the finger against the glass, the counter will continuously
cycle the numeral indicated on the display 18 from 0 to 9. The
display 18 should be located for ready viewing by the operator so
that the operator may remove his finger from the glass when the
desired digit is displayed, i.e., the first digit of the
combination. Removal of the finger to "freeze" the digit indicated
on the display 18 will enable the decoder 20 to provide an output
signal on one of the 0 to 9 output terminals.
Should the first decoded digit be 0, 2-6 or 8 for the exemplary 1,
7, 9 combination illustrated, the logic circuit 22 will immediately
reset. Should the first decoded digit be the digit 7 or 9, the
logic circuit 22 will also reset. Should the first decoded digit be
the digit 1, i.e., the first digit of the combination, the logic
circuit 22 will internally prepare for receipt of the next digit of
the combination, i.e., the digit 7.
If the operator does not again place his finger on the glass to
effect operation of the switch 10 within a predetermined time
interval, e.g., ten seconds, the timing circuit 26 will reset the
logic circuit 22. Should the operator again effect operation of the
switch 10, the counter 14 will be reset and again cycle the display
18 until the operator recognizes the second digit of the
combination and removes his finger from the glass to "freeze" the
display. If the second digit decoded is other than the second digit
of the combination, the logic circuit 22 will reset. If, however,
the second decoded digit is the second digit of the combination,
the logic circuit 22 will be internally enabled to receive the
third digit of the combination. The subsequent receipt of the third
digit will effect operation of the lock 24 for a predetermined time
interval sufficient to permit entrance into the enclosure.
The circuit may be provided with feedback from the locking
mechanism to disable the display 18 so that the last digit of the
combination cannot be observed by an unauthorized person. Also, the
display 18 may be desirably shielded to prevent observation of the
display during the operation of the mechanism.
The physical relationship of the switch 10 may be as illustrated in
FIGS. 2 and 3. With reference now to FIGS. 2 and 3, an opening 28
may be provided from the inside of an external wall and the opening
covered by a one-quarter inch thick sheet 30 of plate glass or
other radiant energy transparent material having the desired
structural characteristics. Any suitable conventional means such as
a metallic plate 32 and a plurality of threaded fasteners 34 may be
utilized to mount the sheet 30 over the opening 28. Thus, a
convenient window is provided against which the finger of the
operator's hand may be positioned.
As indicated in FIGS. 2 and 3, two zones 38 and 40 may be provided
in the window by the positioning of detectors 42 and 44. As
indicated schematically in FIG. 3, a suitable shield or baffle 46
may be provided to optically isolate the detectors 42 and 44 from
radiation passing through all but the particular zone 38 or 40 with
which it is associated. Thus, the presence of a finger 36 at one of
the zones in the window will optically block the radiant energy
normally incident thereon and provide an output signal from the
switch as will be subsequently explained in greater detail in
connection with the circuit of FIG. 4.
With reference now to FIG. 4, the switch 10 of FIG. 1 may include a
PNP transistor Q1 connected between a 5-volt source of positive
potential and ground potential by an emitter resistor 50 and a
collector resistor 52. The bias for the base electrode for the
transistor Q1 may be provided by any suitable conventional radiant
energy responsive devices 54 and 56 located respectively in the
base-to-emitter and base-to-collector circuits of the transistor
Q1. The output signal from the transistor Q1 may be taken from the
collector electrode thereof and passed through a resistor 58 and
the parallel combination of a resistor 60 with a pair of serially
connected converters 62 and 64 as the output signal from the switch
10.
The output signal from the switch 10 may be, as shown in FIG. 1,
applied to an oscillator circuit 12, a timing circuit 26 and a
logic circuit 22. The oscillator circuit 12 may comprise a diode 66
in series with a parallel circuit in which a capacitor 68 is
provided in one branch thereof and in which the other branch
thereof includes an inverter 70 in series with the parallel
combination of an inverter 72 and a variable resistor 74. The
output signal from the oscillator circuit 12 may be passed through
a capacitor 76 to the input terminal of a suitable conventional
decade counter 14. The decade counter 14 may be provided with
parallel output terminals representing the binary digits 1, 2, 4
and 8 and these output terminals may be connected to input
terminals of a driver decoder circuit 20 which, when enabled, may
apply binary coded signals to a suitable conventional display
circuit 18 such as an alphanumeric electronic tube. The output
signals from the driver decoder circuit 20 may also be applied to
the input terminals of a binary coded decimal to decimal decoder 78
of the logic circuit 22.
With continued reference to FIG. 4, the output signal from the
switch 10 may also be provided to the timing circuit 22 which may
include the series connection of a resistor 80, diodes 82 and 84
and a resistor 86 and the series connection of a resistor 88 and a
pair of inverters 90 and 92 in parallel therewith. The
interconnection of the diodes 82 and 84 may be directly connected
to the interconnection of the resistor 88 and the inverter 90 and
isolated from ground potential by way of a capacitor 94. The output
signal from the inverter 92 may be used as the RESET signal applied
to the decade counter 14 and the output signal from the diode 90
may be utilized as the BLANK signal for application to the driver
decoder circuit 20 and one input terminal 94 of a NAND gate 96.
The logic circuit 22 of FIG. 4 may include a plurality of NAND
gates 98, 100, 102 and 104, each connected to receive on one input
terminal thereof the output signal from the switch circuit 10. Each
of the NAND gates 100, 102 and 104 receives an input signal from a
predetermined one of the decimal output terminals of the binary
coded decimal to decimal decoder 78. In the preferred embodiment
illustrated, the combination is a 3-digit combination with the "1"
output terminal of the decoder 78 connected to the other input
terminal of the NAND gate 100, the "7" output terminal connected to
the other input terminal of the NAND gate 102 and with the "9"
output terminal connected to the other input terminal of the NAND
gate 104.
Any suitable conventional means may be used to effect the selected
connection of NAND gate 100, 102 and 104 to the selected output
terminals of the decoder 78 to thereby establish the desired
combination. Similarly, the connection of each of the
noncombination digit output terminals of the decoder 78 to the NAND
gate 98 may be effected by any suitable conventional means.
The output signal from the NAND gate 100 may be applied to a timing
circuit 106 to enable a NAND gate 108 for a predetermined time
interval. Similarly, the output signal from the NAND gate 102 may
be applied to the timing circuit 110 to enable a NAND gate 112 and
the output signal from the NAND gate 104 applied through a timing
circuit 114 to provide a signal at the other input terminal 116 of
the NAND gate 96. The output signal from the NAND gate 96 may be
connected to the relay coil 118 of a switch within the lock 24.
In operation, the placing of a finger to block the ambient light to
the detector 42 of FIG. 3 may effect the unbalancing of the bias of
the transistor Q1 to drive the transistor into cutoff. The output
signal from the collector electrode of the transistor Q1 will
assume a low signal level and the circuit including the invertors
62 and 64 operate as a Schmitt trigger to remove the normally high
signal level signal from the oscillator 12, the timing circuit 26
and the decoder and logic circuit 22.
Removal of the signal from the timing circuit 26 will effect the
generation of the RESET signal applied to the decade counter 14 to
effect the resetting thereof and will also remove the normally high
signal level BLANK signal from the driver decoder 16 so that the
decoder 16 will be operative to drive the display 18 to visually
indicate the digit in the counter 14. Removal of the BLANK signal
will also enable the NAND gate 96 of the decoder and logic circuit
22.
The removal of the input signal from the oscillator 12 will effect
the application of periodic pulses to the decade counter 14 through
the capacitor 76. The incrementing of the decade counter 14 will
provide the signals necessary to operate the display 18 through the
driver decoder 16.
When the finger is removed from the position illustrated in FIG. 3,
the transistor Q1 again saturates to disable the oscillator 12.
Because of the time constants of the resistor 88 and capacitor 94,
the resetting and blanking functions do not recur for a
predetermined time interval, e.g., 10 seconds. If the switch 10 is
again activated within this predetermined time interval, the
oscillator 12 again increments the counter 14 to cycle the display
18 until such time as the finger of the operator is again removed
to disable the switch 10. This process is repeated until the
operator sequentially "freezes" by the removal of his finger at an
appropriate time, each digit of the combination on the display
18.
The removal of the finger to "freeze" the digit displayed enables
each of the NAND gates 98, 100, 102 and 104 of the decoder and
logic circuit 22. Should the decoder 78 provide a low signal level
signal on any of the output terminals 0 2-6 or 8, the NAND gate 98
will be disabled to disable the NAND gate 96 and thus the operation
of the lock 24. Should the decoder 78 provide the NAND gate 100
with an appropriate low signal level signal during this time, the
NAND gate 100 will enable the NAND gate 108 so that the NAND gate
96 will remain in an enabled condition. Should the decoder 78
provide a "7" output signal during this first sampling of the
decoder 78, the NAND gate 102 will inhibit the NAND gate 108 and
thus the NAND gate 96 and the operation of the lock 24. Similarly,
the presence of a "9" output signal from the decoder 78 during this
first sampling interval will inhibit the NAND gate 96 through the
operation of the NAND gate 104.
At the time of the next sampling interval, e.g., when the finger is
again removed to "freeze" the second digit of the combination in
the display 18, the NAND gate 102 will operate to enable the NAND
gate 112 and maintain the NAND gate 96 in an enabled condition. The
subsequent receipt of a "9" signal from the decoder 78 by the NAND
gate 104 will effect the operation of the NAND gate 96 to operate
the relay 118 associated with the lock 24.
ADVANTAGES AND SCOPE OF THE INVENTION
Many of the advantages of the present invention will be readily
apparent from the foregoing description of a preferred embodiment.
For example, the optical keyboard of the present invention utilizes
ambient radiation easily blocked by the human finger.
Another of the major advantages of the present system is that
observation of theh time intervals in which the finger is placed in
proximity to the zone of the keyboard is easily hindered to protect
the combination of the lock. Further, the difficulty in measuring
time intervals is advantageous. The display of but a single digit
at one time and an automatic reset feature precludes any residual
indication of the combination as may exist where the combination is
set by a plurality of switches or the like.
Because of the resetting of the logic circuit upon the detection of
a single out-of-sequence time interval, security is assured. It
will be further appreciated that the combination cannot be detected
by a sense of feel or mechanical noise since no mechanical
combination locking or unlocking apparatus is utilized.
Moreover, the ease with which the combination may be changed
facilitates revision of the security measures and thus reduces the
likelihood of compromise. Since the device is finger operated,
there are no keys to be lost or stolen.
Another of the major advantages of the present invention is the
complete lack of moving parts in the operation of the system. The
use of plate glass provides the desired structural strength and
obviates the necessity for an opening which may be obstructed by
children or vandals.
The present invention may thus be embodied in other specific forms
without departing from the spirit or essential characteristics
thereof. The presently disclosed embodiments are therefore to be
considered in all respects as illustrative and not as restrictive,
the scope of the invention being indicated by the appended claims
rather than by the foregoing description, and all changes which
come within the meaning and range of equivalancy of the claims are
therefore intended to be embraced therein.
* * * * *