U.S. patent number 3,893,073 [Application Number 05/440,202] was granted by the patent office on 1975-07-01 for keyless control mechanism.
This patent grant is currently assigned to Westinghouse Electric Corporation. Invention is credited to Paul S. Angello.
United States Patent |
3,893,073 |
Angello |
July 1, 1975 |
Keyless control mechanism
Abstract
A controlled display device sequentially displays code
information which is viewable only to an observer positioned at a
critical angle relative to the display device. The observers
actuation of a device acknowledging a predetermined sequence of
code information results in the generation of a control signal.
Inventors: |
Angello; Paul S. (Los Angeles,
CA) |
Assignee: |
Westinghouse Electric
Corporation (Pittsburgh, PA)
|
Family
ID: |
23747849 |
Appl.
No.: |
05/440,202 |
Filed: |
February 6, 1974 |
Current U.S.
Class: |
340/5.54;
361/172; 340/5.7 |
Current CPC
Class: |
G07C
9/00698 (20130101); G07F 7/10 (20130101) |
Current International
Class: |
G07F
7/10 (20060101); G07C 9/00 (20060101); E05b
049/00 (); H04q 003/02 () |
Field of
Search: |
;340/147R,149R,164A,164R
;317/134 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Yusko; Donald J.
Attorney, Agent or Firm: Lynch; M. P.
Claims
I claim:
1. Apparatus for generating a control signal in response to
predetermined input signals, comprising, first means for
sequentially displaying information for viewing by an observer,
said first means including a display window having a critical
viewing angle requiring the observer to assume a specific position
relative to the display window in order to view the displayed
information, second means including a single actuator means
permitting an observer to selectively acknowledge displayed
information and produce signals indicative of the acknowledged
display information, and third means operatively connected to said
second means and responding to said signals to determine if the
acknowledged information corresponds to predetermined information,
said third means producing a control signal if said acknowledged
information corresponds to said predetermined information.
2. Apparatus claimed in claim 1 wherein said display window
consists of a light control film.
3. Apparatus claimed in claim 1 wherein said display window
includes louvers arranged to establish a critical viewing angle for
observing the displayed information.
4. Apparatus claimed in claim 1 wherein said third means includes
mechanical thumbwheel switch means for changing said predetermined
information.
Description
BACKGROUND OF THE INVENTION
The use of keyless locks and keyless actuating devices, for
numerous military, industrial, and residential security
applications has resulted in the development of numerous mechanical
and electrical control systems. Numerous available keyless control
systems are of the form whereby the person desiring entry to a
protected area or desiring to initiate a predetermined control
function communicates to the keyless security device in an attempt
to match preset encoded information. This encoded information is
either stored electrically by the absence or presence of voltages
or mechanically by the positioning of slides or other mechanical
parts. The system typically includes multiple actuating switches or
buttons on an exposed face panel. The individual desiring to
initiate a control function or desiring to obtain entry is required
to actuate the buttons in a predetermined sequence which satisfies
the encoded information. This type of a security system lends
itself to unwanted observation by an unauthorized individual as
well as unwanted tampering.
SUMMARY OF THE INVENTION
There is disclosed herein with reference to the accompanying
drawings a control mechanism which communicates with the person
desiring entry or desiring to initiate control function by means of
a display system which sequentially presents to the individual
information to which the observer is required to respond by
actuating a single button. The system may be programmed to require
the observer to actuate the button in response to one or more code
characters displayed to achieve the desired entry or initiate the
desired control function. The use of a display screen having a
critical viewing angle, which can be suitably implemented through
the use of light control film such as that available from the 3M
Company, severely limits the angle at which an observer can view
the displayed code characters. The use of such a display screen
prevents unauthorized observation of the display code characters.
This system eliminates the need for a plurality of actuating
devices or buttons which through normal wear could easily disclose
the buttons representing the encoded information.
DESCRIPTION OF THE DRAWINGS
The invention becomes more readily apparent from the following
exemplary description in connection with the accompanying
drawings:
FIG. 1 is a pictorial representation of an embodiment of the
invention;
FIG. 2 is a pictorial illustration of the use of louvers in the
display window of FIG. 1; and
FIG. 3 is a block diagram schematic illustation of an embodiment of
the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is pictorially represented a control
system 10 including a display panel 12 consisting of a display
screen 14 and a display information match-button 16. The control
system 10 of FIG. 1 is utilized in a security application whereby
the output signal generated by the control system 10 is functioned
to actuate the door-lock mechanism 20. While the discussion to
follow will make use of the security application for the purposes
of identifying a practical utilization of the invention, it will be
apparent that the concept disclosed is adaptable to numerous
control system applications.
In the embodiment illustrated in FIG. 1, a stored code is produced
by the setting of thumbwheel switches 18. One or more thumbwheel
switches can be utilized depending on the application of the
control system. The stored code established by the thumbwheel
switches 18 must be satisfied before the control signal is
transmitted to actuate the door-lock mechanism 20. An observer
desiring entry to the secured area is required to actuate
match-button 16 in response to stored code as it is presented in
display window 14. Therefore, in order for an observer to gain
access to the secured area he must recognize the stored code
established by the thumbwheel switches 18 by the proper actuation
of the match-button 16. While the embodiment of FIG. 1 utilizes
thumbwheel switches 18 for the purpose of establishing the stored
code which must be satisfied to produce a control output signal, it
is apparent that numerous techniques are available for implementing
the requirement for establishing a stored code.
A particularly desirable feature of the control system 10 is the
use of a critical viewing angle display window 14 which affectively
prevents individuals position other than directly in front of the
display window 14 from observing the sequential information
displayed to which an observer responds by actuating the
match-button 16. This feature prevents an unauthorized observer
from gaining access to the correct stored code information. The
critical viewing angle display window can be achieved through the
use of louvers or through the use of light control film as
identified above. The flashing display viewed through the display
window 14 can be typically implemented through the use of a light
emitting diode (LED) display. FIG. 2 is an illustration of the use
of louvers L to establish the critical viewing angle.
There is illustrated schematically in FIG. 3 a typical arrangement
of components to implement the operation of the control system of
FIG. 1. The schematic embodiment of FIG. 3 includes three basic
circuits, a Flash Circuit FC, a Counter Control Circuit CC and a
Match Circuit MC.
The initial actuation of the match button 16 develops a signal
which is supplied as an input signal to the control counter 40, the
push clear OR circuit 42, and the match AND gate circuit 44. The
input signal to the control counter 40 shifts the output to
position number 1 which in turn feeds the start flash OR circuit
26. Inasmuch as the OR gate 26 requires only one input to develop
an output signal, the output signal thus developed is not only
supplied to gate the start flash AND circuit 24 as indicated above,
but also serves as a second input to match AND gate circuit 44. The
number 1 output of the control counter 40 is thus a logic high
which causing energization of thumbwheel switch 10.sup.3. The
observer desiring entry to the secured area now views the sequence
of numbers presented to him in the display windows 14 of the Flash
Circuit FC and acknowledges the number representing the first
correct number of the stored code developed by the thumbwheel
switches 18 by actuating the match button 16. If the operation of
the match button 16 corresponds to the first number of the stored
code the binary number comparator 46 develops a logical high output
signal which is supplied as a third input to the match AND gate
circuit 44.
A Schmitt trigger circuit 22 in the Flash Circuit FC responds to a
60 Hz sinewave by converting the 60 HZ sinewave to a 60 cycle
square wave signal as illustrated. This squarewave is then applied
as one input to a start flash AND gate 24. If a logic input signal
is coincidentally supplied to the second input of the start flash
AND gate 24 from the start flash OR gate 26, the 60 Hz square wave
pulse is gated through the start flash AND gate to a divide by 72
circuit 28 which develops a five/sixths Hertz flash frequency
output signal. The flash frequency signal is supplied as an input
to the decade counter 30 which responds by developing a count
sequence from 0 and 9 and then resets to 0. The count sequence
developed by the decade counter 30 is supplied in binary form to a
seven segment LED display 32, which functions to present the 0
through 9 information to the observer through the display screen
window 14 or FIG. 1. Initially, in the system standby condition, a
0 is present in the display window 14 and all system counters are
set at 0.
The match AND gate circuit 44 responds to the presence of the three
input signals by transmitting a logical high signal as an input to
the match counter 48. The match counter 48 responds to the input
signal by shifting from position 0 to position 1 while the control
counter 40 is shifting from position 1 to position 2 in response to
the actuation of the match button 16. Furthermore the actuation of
the match button 16 transmitts a signal through the push clear OR
circuit 50 which functions to both clear the divide by 72 circuit
28 and the decade counter 30 thus bringing the display back to 0.
This alerts the observer to the fact that a flash display for the
second number of the stored code sequence will soon be
initiated.
In anticipation of the second match button actuation the control
counter 40 is located at position 2 and is thus set to energize the
10.sup.2 thumbwheel switch and the match counter 48 is located at
position 1 indicating that there has been one correct match
entered. Again in the second display sequence when the number
presented in the display window 14 agrees with the binary number
encoded in the binary comparator circuit 46 by the 10.sup.2
thumbwheel switch a logical high is developed at the match AND gate
circuit 44 thus requiring actuation of the match button 16 in order
to enter another correct match through the match AND gate circuit
44. Assuming a correct actuation of the match button 16 occurs, the
logic output signal developed by the match AND gate 44 will cause
the match counter 48 to be shifted to position 2 and the control
counter 40 will be setting at position 3. Once again the display
will be cleared. The same procedure as described above is repeated
for the match of he stored code information developed by the
10.sup.1 thumbwheel and the 10.sup.0 thumbwheel.
In the event the match button is not depressed or depressed in
response to an incorrect display number the control counter 40 will
be shifted one position as usual thus clearing the display, but the
match counter 48 will not be shifted.
Prior to the fourth and final actuation of the match button 16 one
of two situations may exist, namely i.e., the first three match
button actuations have matched the first three numbers in the four
number stored code or one or more of the first three match button
actuations has not matched the corresponding information in the
stored code.
Assuming the first situation where three correct entries have been
entered. Under these circumstances the match counter 48 will be in
position 3, the control counter 40 will be in position 4, as it
would whether the first three entries were correct or not, and the
10.sup.0 thumbwheel switch would be energized. Assuming the
observer actuates the match button 16 in response to the display of
the fourth number in the stored code the match counter 48 will be
stepped to position 4 and the control counter 40 will be stepped to
position 5. This results in output signals from the control counter
40 and the match counter 48 which are transmitted as inputs to the
match insurance AND gate. The occurrence of simultaneous inputs at
match insurance AND gate 50 results in a control signal output from
the match insurance AND gate which is transmitted through an
amplifying circuit 52 to actuate the lock mechanism 20. A time
delay circuit is typically included to maintain the control system
output signal for a limited period of time.
The output signal from the match insurance AND gate 50 is also
supplied as an input to the cycle clear OR gate 54 with the
corresponding output of the cycle clear OR gate being supplied as
an input signal the push clear OR circuit 42 thus insuring a reset
of the display to 0. The output of the cycle clear OR circuit is
also applied to the clear inputs of the control counter 40 and the
match counter 48. After the control signal is terminated the
control system 10 is returned to a standby condition with all
counters set on 0 and a 0 appearing in the display windown 14.
Assuming now the situation where the first three actuations of the
match button 16 have not satisfied the stored code and a fourth
match button acutation is about to be entered. The final actuation
of the match button 16, whether it corresponds to a correct or
incorrect match, will cause the control counter 40 to be stepped to
position 5 causing an output signal to be transmitted through the
cycle clear OR gate 54 to produce a cycle clear and assure the
transmission of a push clear signal by push clear OR gate 42. This
operation assures the resetting of all the counter to 0 and returns
of the display to 0. Thus the system is again established in a
standby state.
It is noted that there are two different types of input signals
possible from the above system. A push clear signal is developed
each time the match button 16 is actuated and functions to reset
the display to 0. The cycle clear signal is produced only after
five actuations of the match button 16, i.e., the first operation
to activate the system and the four match button actuations
initiated in an effort to match the stored code established by the
thumbwheels 18. This cycle clear signal is produced after the five
actuations of the match button 16 regardless of the accuracy of the
match button acutations.
The operational integrity of the control system 10 is improved by
several circuit refinements. For instance there are three inputs
instead of two to the match AND gate 44 thus requiring a start
flash signal to be present indicating that the counting sequence is
occurring. If this input signal is not required it would be
possible to match 0 since that is the standby condition and there
is a 0 displayed in the window. Additional operational integrity is
provided by the match insurance AND circuit 50 which requires not
only the presence of the fourth match, as reflected by the match
counter 48, before generating a control signal output but also
requires control counter 40 to be located at position 5.
* * * * *