United States Patent [19]
`Foster, Jr.
`
`I I IIIIIII Ill lllll 11111111111111011110 11111111111111111 IIII
`
`US005668929A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,668,929
`Sep. 16, 1997
`
`[54] SPEECH ACTIVATED SECURITY SYSTEMS
`AND METHODS
`
`[75]
`
`Inventor: Richard W. Foster, Jr .. Costa Mesa,
`Calif.
`
`[73] Assignee: Hirsch Electronics Corporation,
`Irvine. Calif.
`
`[21] Appl. No.: 686,824
`Jul. 22, 1996
`
`[22] Filed:
`
`Related U.S. Application Data
`
`[51]
`
`[63] Continuation of Ser. No. 417,098, Apr. 5, 1995, abandoned,
`which is a continuation of Ser. No. 7,096, Jan. 21, 1993,
`abandoned.
`Int. CI.6
`............................... G06F 7/04; H03G 3/20;
`GlOL 3/00
`[52] U.S. Cl . .................... 704/273; 340/825.31; 367/198;
`381/110
`[58] Field of Search ............................ 340/825.3, 825.31.
`340/825.34; 367/198. 199; 307/117; 235/382;
`382/118; 381/41, 42. 43, 110; 395/2.82
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENfS
`
`3,893,073
`3,969,584
`4,032,931
`4,333,090
`4,340,797
`4,449,189
`4,479,112
`4,502,048
`4,644,326
`4,653,097
`4,856,072
`4,870,686
`4,975,959
`
`7/1975 Angello .............................. 340/825.31
`7/1976 Miller et al ........................ 340/825.31
`6/1977 Haker ................................... 340/825.3
`6/1982 Hirsch .................................. 340/825.3
`7/1982 Takano et al ........................... 367/198
`5/1984 Feix et al .................................. 381/42
`10/1984 Hirsch ................................ 340/825.31
`2/1985 Rehm ................................. 340/825.31
`2/1987 Villalobos et al ..
`3/1987 Watanabe et al ......................... 381/42
`8/1989 Schneider et al .................. 340/825.31
`9/1989 Gerson et al. . ........................... 381/43
`12/1990 Benbassat ................................. 381/41
`
`5,027,406
`5,153,918
`5,163,111
`5,222,152
`
`6/1991 Roberts et al. . .......................... 381/43
`10/1992 Tuai .
`11/1992 Baji et al ..
`6/1993 Fishbine et al .................... 340/825.34
`
`Primary Examiner-Larry D. Donaghue
`Assistant Examiner-Mark H. Rinehart
`Attorney, Agent, or Firm-Blakely. Sokoloff, Taylor &
`ZafmanLLP
`
`[57]
`
`ABSTRACT
`
`Speech actuated security devices and methods whereby a
`lock. or other security or access device, may be actuated by
`a speech input thereto. but without disclosure of the actual
`code where doing so to those hearing the code words spoken
`during use of the security device. The security device
`includes a microphone. a display for displaying a plurality of
`· code elements, and a processor for controlling the display
`and analyzing the microphone signal to detect a proper
`sequence of code elements spoken by a user as detected by
`the microphone and to operate the security device in
`response thereto. The code elements are displayed on the
`display under processor control in various patterns. With the
`proper sequence of code elements for operation of the
`security device not being a preset sequence of code
`elements, but rather being the code elements which appear
`in each of a proper sequence of spatial code element
`positions in the pattern of code elements being displayed by
`making the code elements displayed in the pattern viewable
`only by the user during use of the security device. Hearing
`the code elements being spoken by the user conveys no
`information about the actual code as a spoken sequence
`which will operate the security device at any one time and
`will change for the next operation of the security device by
`the reassignment of the code elements to new spatial posi(cid:173)
`tions within the pattern of code elements in the display.
`Various embodiments and methods of operation thereof are
`disclosed.
`
`41 Claims, 5 Drawing Sheets
`
`sound
`change
`
`~ I
`
`pick scrambled colle
`element pos1t1ons and
`tum on the display
`
`conuer1 speech data
`to code elemenl5
`
`convert code elements 10
`code element posillons
`
`code element position
`sequence
`
`valid code element
`posilion seQuence
`?
`
`Page 1 of 13
`
`GOOGLE EXHIBIT 1018
`
`

`

`U.S. Patent
`
`Sep. 16, 1997
`
`Sheet 1 of 5
`
`5,668,929
`
`20
`
`)
`
`28
`
`26
`
`@
`©@@
`©@©
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`@
`
`Fig. 1
`
`24
`
`22
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`
`28
`
`26
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`0
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`
`26 Fig. 2
`
`28
`
`26
`
`22
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`
`26
`
`26
`
`22
`_)
`
`26
`
`Fig. 3
`
`Fig. 4
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`Page 2 of 13
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`

`

`U.S. Patent
`
`Sep. 16, 1997
`
`Sheet 2 of 5
`
`5,668,929
`
`28
`
`26
`
`22
`_,)
`
`28
`
`26
`
`Fig. 5
`
`Fig. 6
`
`26
`
`Fig. 8
`
`Fig. 7
`
`24
`
`MIC
`
`DISP
`
`64
`
`COMM
`
`52
`RNRLOG
`
`70
`
`68
`
`SYS
`PWR
`
`BRTTERY
`PRCK/PUJR
`
`Fig. 9
`
`62
`LOCK
`CONT
`
`66
`
`LOCK
`
`Page 3 of 13
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`

`

`U.S. Patent
`
`Sep. 16, 1997
`
`Sheet 3 of 5
`
`5,668,929
`
`sound
`change
`
`turn on
`
`set tries = 3
`
`pick scrambled code
`element positions and
`turn on the display
`
`conuert speech data
`to code elements
`
`conuert code elements to
`code element positions
`
`indicate
`failed
`attempt
`
`sequence
`=
`ualid code element
`position sequence
`?
`
`no
`
`tries
`=
`tries - 1?
`
`yes
`
`turn off
`
`Fig. 10
`
`no
`
`yes
`
`disable for
`a time
`
`Page 4 of 13
`
`

`

`U.S. Patent
`
`Sep. 16, 1997
`
`Sheet 4 of 5
`
`5,668,929
`
`~ ~
`800
`®®©
`0©0
`®©©
`00®
`®©©
`
`Fig. 1 2
`
`Fig. 11
`
`88
`
`24
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`~
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`Fig. 13
`
`86 D
`
`82
`
`84
`
`80
`
`Fig. 14
`
`Page 5 of 13
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`

`

`U.S. Patent
`
`Sep. 16, 1997
`
`Sheet 5 of 5
`
`5,668,929
`
`sound
`change
`
`~
`
`set tries= 3
`
`pick scrambled code
`element positions and 14-------1
`turn on the display
`
`indicate
`failed
`attempt
`
`conuert speech data
`to code elements
`
`conuert code elements to
`code element positions
`
`sequence
`=
`ualid code element
`position sequence
`?
`
`no
`
`tries
`=
`tries - 1?
`
`yes
`
`turn off
`
`Fig. 15
`
`no
`
`yes
`
`disable for
`a time
`
`Page 6 of 13
`
`

`

`5,668,929
`
`1
`SPEECH ACTIVATED SECURITY SYSTEMS
`AND METHODS
`
`1bis is a continuation of application Ser. No. 08/417,098,
`filed Apr. 5. 1995. which was a continuation of application 5
`Ser. No. 08/007.096. filed Jan. 21. 1993, both now aban-
`doned.
`
`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`The present invention relates to the field of high security
`locks and related security devices.
`2. Prior Art
`High security locks and similar security devices of vari(cid:173)
`ous kinds are well-known in the prior art. One type of such
`lock of particular interest to the present invention is key(cid:173)
`board operated locks wherein users of the locks are provided
`a code which. when entered into the keyboard, will operate
`the same. Such codes may be lock dependent. essentially
`serving as a combination for the lock. may be user
`dependent, essentially identifying the user to the lock
`system. or may be a combination of lock and user dependent.
`An example of the first type of lock are locks controlling
`access to parts of a secure facility, whereas locks of the
`second type include those used as part of an automatic teller
`machine to enable function keys which allow one to with(cid:173)
`draw money and conduct other transactions. In that regard,
`the words lock. locks and security devices as used herein are
`used in a general sense to denote a means for granting access
`to a place or enabling a function or an action which is
`otherwise disabled. such as the operation of a door latch or
`the withdrawal of funds in an automatic teller machine or
`other services. communication devices, computing devices,
`cash machines, point of sale terminals, etc., or alternatively,
`the disabling of something which is normally enabled, such
`as might be required to lock or disable something normally
`left unlocked or enabled.
`In a conventional keyboard operated lock. the level of
`security attained is relatively low because the number to key 40
`assignments are fixed and ordered, and the sequence of key
`depressions of a user are normally observable from either
`side of the user without substantial difficulty. To alleviate
`this problem and enhance the security of the overall system,
`keyboards are known wherein the keys are not given a 45
`predetermined and ordered 1-2-3 type sequence, but rather
`are given identifications Just prior to use which identifica(cid:173)
`tions are effectively scrambled before the next such use. In
`this manner the physical key depression sequence observed
`during one operation of the system will have no meaning
`during the next operation of the system when the keys are
`identified differently. Further, in such systems the key iden(cid:173)
`tifications appearing when the user is standing in front of the
`keyboard are highly directional, and not observable from the
`side. Thus. the body of the user blocks the key identifications
`from view by others, so that while the physical key depres(cid:173)
`sions can be observed from the side, the key identifications
`associated therewith cannot similarly be determined. Appa(cid:173)
`ratus of this general type is disclosed in U.S. Pat. Nos.
`4,644326. 4,479,112. 4,333.090 and 4,502,048. Also, 60
`another device having security features which include physi-
`cal screening as well as mechanical and electronic realign(cid:173)
`ment of numeric key entry functions is disclosed in U.S. Pat.
`No. 4.032,931.
`Apparatus of the foregoing type provides a high level of 65
`security. as no information concerning the code for operating
`the lock. which may be personal to a specific user. is
`
`2
`conveyed to an interloper watching the sequence of key
`depressions used to operate the security device unless the
`interloper could somehow simultaneously view and record
`or memorize the code element pattern being displayed in
`association with the keys. However, such a security device
`is relatively expensive, primarily because of the mechanical
`complexity of the manually operable keys, the preferred
`positioning of each display device for the code elements
`behind each key, and the structure for reliably and substan-
`10 tially completely limiting the viewability of the display to
`the user. Such a security device can exhibit less than
`maximum reliability because of the mechanical nature of the
`basic input to the device. The keyboard. requiring manual
`operation, is quite limited regarding minimum allowable
`15 size because of the need for a user, perhaps a large man, to
`conveniently depress one key at a time with his finger. Also
`the keyboard. used by all persons, may be considered by
`some to be unacceptably unsanitary, and of course, because
`of the basic mechanical input requirements thereto, cannot
`20 be operated by one having their hands full without setting
`things down to operate the security device. Furthermore, a
`person with a physical disability affecting the use of their
`digits or without digits or hands cannot use such a device.
`Thus, it would be desirable to provide a new security
`25 device which would maintain or even enhance the level of
`security achieved by the hereinbefore described devices, but
`in a manner eliminating the mechanical complexity and
`resulting lower reliability thereof while at the same time
`allowing for a smaller and substantially less expensive
`30 security device.
`
`BRIEF SUMMARY OF THE INVENTION
`Speech actuated security devices and methods whereby a
`lock. or other security or access device, may be actuated by
`35 a speech input thereto, but without disclosure of the actual
`code where doing so to those hearing the words during use
`of the security device. The security device includes a
`microphone, a display for displaying a plurality of code
`elements, and a processor for controlling the display and
`analyzing the microphone signal to detect a proper sequence
`of code elements spoken by a user as detected by the
`microphone and to operate the security device in response
`thereto. The code elements are displayed on the display
`under processor control in various patterns. With the proper
`sequence of code elements for operation of the security
`device not being a preset sequence of code elements, but
`rather being the ccxle elements which appear in each of a
`proper sequence of spatial code element positions in the
`pattern of code elements being displayed by making the
`50 code elements displayed in the pattern viewable only by the
`user during use of the security device. Hearing the code
`elements being spoken by the user conveys no information
`about the actual code as a spoken sequence which will
`operate the security device at any one time and will change
`55 for the next operation of the security device by the reas(cid:173)
`signment of the ccxle elements to new spatial positions
`within the pattern of code elements in the display. Various
`embodiments and methods of operation thereof are dis(cid:173)
`closed.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a face view of one embodiment security device
`in accordance with the present invention.
`FIG. 2 is a face view of the security device of FIG. 1 in
`the quiescent state.
`FIG. 3is a face view of the security device of FIGS. 1 and
`2 as displaying the digits O through 9 in a scrambled order.
`
`Page 7 of 13
`
`

`

`5,668,929
`
`3
`FIG. 4 is a face view of the security device of FIGS. 1, 2
`and 3 as displaying the digits 0 through 9 in a different
`scrambled order after that of FIG. 3.
`FIG. 5 is a face view of the security device of FIGS. 1, 2
`and 3 as displaying the digits 0 through 9 in an alternate next 5
`scrambled order after that of FIG. 3.
`FIG. 6 is a face view of a still further embodiment of the
`invention.
`FIG. 7 is a face view of a further embodiment using a
`horizontal linear or one-dimensional array of code elements.
`FIG. 8 is a face view of a further embodiment using a
`vertical linear or one-dimensional array of code elements.
`FIG. 9 presents a block diagram of a representative
`electronic control for the present invention.
`FIG. 10 presents a representative flow diagram for the
`operation of the lock.
`FIG. 11 is a face view of a further embodiment of the
`present invention utilizing letters as code elements the
`position of which will be scrambled for each operation of the 20
`lock.
`FIG. 12 is an embodiment similar to that of FIG. 11
`utilizing symbols or objects as code elements rather than
`numbers or letters.
`FIG. 13 is an embodiment similar to that of FIGS. 11 and
`12 though illustrating the use of a combination of letters,
`numbers and symbols.
`FIG. 14 is a face view of an embodiment of the present
`invention utilizing a display screen which may be a touch
`screen for verbal or manual entry of code element positions
`or code elements and further including a video camera for
`displaying recording and/or analyzing the image of a user of
`the lock typically upon successful or unsuccessful operation
`of the lock or both.
`FIG. 15 presents an alternate to the representative flow
`diagram of FIG. 10 for the operation of the lock.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`First referring to FIG. 1, a face view of one embodiment 40
`security device in accordance with the present invention
`may be seen. In particular, security device 20, which in a
`controlled entry facility may be mounted on a door or
`adjacent a door for controlled access, is characterized by an
`armored enclosure 22 having a microphone pickup 24 and 45
`ten code element display positions thereunder, each
`shrouded by an appropriate shroud 24 and/or covered by an
`appropriate slatted baffle so as to be viewable only through
`a narrow range of angles, particularly in the horizontal
`plane, so that an operator aligned with the display for proper 50
`viewing thereof will physically prevent similar viewing by
`an interloper therebehind by the presence of the user's body.
`In that regard, methods and apparatus for limiting the
`viewing angle of a display are well known. See for instance
`the disclosure of U.S Pat. No. 4,479,112.
`For convenience, in the embodiment of FIG. 1, the code
`element positions are arranged in a two dimensional spatial
`pattern duplicating the arrangement of digits on a push
`button telephone. Such an arrangement will be immediately
`familiar to substantially any security device user, and
`accordingly is convenient to use, though as shall subse(cid:173)
`quently be seen, other arrangements and/or other numbers of
`code elements, as well as code elements of other forms or
`characters commonly recognizable or arbitrary in appear(cid:173)
`ance may be used as desired.
`As may be seen in FIG. 1, the code element positions are
`numbered in the Figure in accordance with the push buttons
`
`10
`
`4
`on a telephone, such as on Touch Tone telephones and the
`like, as a number associated with each such position will be
`immediately familiar to users of the security device.
`However, it is to be noted that such numbering is for the
`purposes of the description herein, and does not physically
`exist on the actual security device 20. Instead, in the
`quiescent state, the security device 20 appears as shown in
`FIG. 2, specifically as having the armored enclosure 22, a
`microphone pickup 24 and ten display locations 26, each
`surrounded by an appropriate shroud 28 for viewing only by
`the user, each display spatial location 26 being capable of
`displaying, by way of a seven segment LED display, a liquid
`crystal display, an incandescent display, a hidden display, a
`holographic display, a heads up display, a CRf display or
`otherwise, any one of the ten digits 0 through 9 at any one
`15 time, but with the display locations not having any
`numbering, specifically any ordered numbering associated
`therewith.
`In the preferred embodiment, FIG. 2 represents the qui(cid:173)
`escent state of the security device, namely with the display
`off and, particularly if battery operated, with the processor in
`a low power or sleep mode awaiting an input to activate the
`same ( a block diagram of the processor and support circuitry
`will be specifically described later). Accordingly, when in
`this quiescent state, the security device 20 must be activated
`25 to proceed with an operating cycle. For this purpose, a push
`button switch or other mechanical activation could be
`provided, though one of the advantages of the preferred
`embodiment of the present invention is complete hands free
`operation of the security device. Accordingly, in the pre-
`30 ferred embodiment, a user will say some initiating word with
`a sufficient volume (microphone signal intensity being aided
`by the fact that the user or operator is in close proximity to
`the security device at that time) to be detected. Such
`activating word or noise will activate the system so that the
`35 processor may thereafter analyze the signal to detect the
`words spoken by the security device user (the words being
`limited to a relatively small vocabulary, including in this
`embodiment the digits 0 through 9). By way of specific
`example, in one embodiment a user might approach the
`security device and say the word "start", which word is
`sufficiently abrupt and short as to represent a readily detect-
`able departure from background noise to activate the system.
`The system might be designed to turn on immediately and to
`catch enough of the word "start" to detect the same, though
`more likely the mere change in volume due to the spoken
`word "start" would simply activate the system in readiness
`to detect and intei:pret further spoken words picked up by the
`microphone.
`Note that the system of the present invention being
`described is based upon principles of speech recognition as
`opposed to voice recognition. More specifically, in the
`embodiment being described, the system will detect and
`recognize any of the digits 0 through 9 as well as generally
`a very limited additional vocabulary, such as, by way of
`55 example, "start", "send", "end", "program" etc., regardless
`of the specific voice used. In that regard, the present inven(cid:173)
`tion security devices and systems may be used alone or
`together with other forms of security, such as by way of
`example, a card reader, biological sensors of some kind such
`60 as a fingerprint sensor, eye separation detector, photo record(cid:173)
`ing and/or verification or other facial or facial feature
`recognition (automatic or through a remotely located secu(cid:173)
`rity officer), etc., or even some level of voice recognition.
`However, except for its possible auxiliary application with
`65 the present invention, the invention being disclosed and
`described is based in the first instance on speech recognition
`rather than voice recognition.
`
`Page 8 of 13
`
`

`

`5,668,929
`
`5
`
`5
`Speech recognition is a technology which is currently
`under development, though clearly has currently reached a
`useful state of development for the present invention. In
`particular, accurate speech recognition in rei!l-time for ordi(cid:173)
`nary conversation with a substantially full vocabulary, par-
`ticularly at a reasonable cost, is still to be desired. In such
`applications. the tendency of a speaker to string words
`together. similar pronunciations of different words, and of
`course the very large base vocabulary all compound the
`problem. However, in systems such as the present invention. 10
`a very limited vocabulary tends to eliminate the need for fine
`distinctions in recognition and the need for any look-ahead
`or look back capability to figure out a questionable word.
`Also the relatively short code and command sets being used
`with the present invention allow a user to pronounce the 15
`same with more clarity and demarcation between words than
`in ordinary speech. Further, because the command and code
`set being spoken at any one time is relatively short, analysis
`of the speech data may be done either substantially in
`real-time as it is received or alternatively after the complete 20
`command and code has been received. providing that the
`delay is only a very few seconds or less. Finally, in the
`present invention an error in speech recognition (for instance
`misinte.rpreting a spoken four for a five or a spoken six for
`a seven) is by no means fatal. as typically the device of the 25
`present invention will be programmed to allow some num(cid:173)
`ber of tries by a user before locking the user out for some
`period of time to prevent the user from systematically trying
`all possible codes. Thus an error in the system incurred
`during a user's first attempt to enter a valid spoken code will 30
`merely alert the user to be a little more careful in his next
`attempted verbal entry of his spatial code pattern.
`Continuing with the description of the operation of the
`embodiment being described, when the user stands before
`the security device 20 and says "start". the processor therein 35
`will cause the displays to display the digits O through 9 in a
`scrambled order. a typical scrambling being shown in FIG.
`3. This scrambled order may be a random order, a pseudo
`random order or one of a large plurality of scrambled orders,
`stored for instance in a look-up table or generated by an 40
`algorithm, perhaps representing more or less than all the
`possible orders of the ten digits. In that regard, the total
`number of possible two-dimensional spatial patterns or
`orders of digits is 10! (ten factorial) or 3,628.800, which
`may be more than one might choose to use in any particular 45
`environment ( see subsequent discussion). In any event, once
`the scrambled digits are displayed for this embodiment, the
`user then recites or pronounces the characters which appear
`in a pre-determined sequence of code element spatial posi(cid:173)
`tions within the spatial pattern of code elements. By way of 50
`example, suppose one has a code corresponding first to the
`2nd code element position (see FIG. 1 for spatial reference),
`then the 3rd code element position, the 8th, the 6th, the 7th,
`and finally the 4th code element position (using the spatial
`position numbering system of FIG. 1 the spatial position 55
`sequence would be 238,674). The user of the security
`device, rather than reciting 2-3-8-6-7-4. recites instead the
`numbers appearing in the positions 2-3-8-6-7-4. namely
`6-0-1-9-5-2 in FIG. 3. in this embodiment followed by the
`word "end". (The use of the word "end" is arbitrary and 60
`unnecessary to require if fixed length codes are used.) The
`processor, as a result of the speech recognition. responds to
`the input of the verbal sequence 6-0-1-9-5-2 by converting
`the verbal sequence back to the code element position spatial
`sequence. recognizes that the code element spatial sequence 65
`is or is not a valid code, and responds accordingly. taking
`appropriate action such as actuating a lock if the code is
`
`6
`valid, or if the code is invalid, somehow indicating the same
`by fault indicating buzzer. voice playback of "code invalid".
`activating an LCD or similar display, etc., and enabling a
`limited number of additional tries before deactivating the
`system for some period of time and/or communicating to a
`remote location the fact that repeated, unsuccessful attempts
`to enter a valid code have been made.
`Upon the next activation of the system. the position of the
`digits will again be scrambled so that the spoken code
`6-0-1-9-5-2 previously received as a valid code and perhaps
`heard by an interloper is no longer valid. In that regard, if
`everyone uses a single spatial sequence as the only valid
`code, then any substantial scrambling will achieve the
`desired result.
`The system could. of course. scramble the spatial pattern
`of code elements after each spoken code element entry,
`although this is not preferred as it would slow the system
`down as well as slow down the users' entry of the code with
`no apparent improvement in security. On the other hand. the
`presentation of the code elements should be scrambled for
`each operation of the security device, as otherwise a spoken
`digit sequence corresponding to a valid spatial position
`sequence of code elements operating the security device one
`time will again immediately be usable on the next subse(cid:173)
`quent use of the security device.
`After the spatial presentation of code elements shown in
`FIG. 3, the next scrambled presentation may be, by way of
`example, such as is shown in FIG. 4, or alternatively, such
`as shown in FIG. 5. In particular. the scrambling of FIG. 4
`in comparison to that of FIG. 3 represents one of many
`possible arbitrary scramblings wherein the spatial position
`of every code element of FIG. 3 has been changed. On the
`other hand, if the scrambling for the subsequent use after
`that of FIG. 3 is in accordance with that of FIG. 5, then the
`spatial position of some, but not all, code elements has been
`changed. Specifically eight of the ten have been changed,
`with the spatial position of code elements five and nine not
`being changed. Similarly, the change from FIG. 4 to FIG. 5
`represents a change in spatial position of nine of the ten code
`elements, the spatial position of code element seven not
`being changed. Thus, as desired, one may allow some
`repetition of code element positions between scramblings or
`alternatively disallow such spatial position repetition. By
`way of example, if the scramblings are achieved by some
`substantially random scrambling. a comparison of a new
`code element spatial position pattern with the previously
`used pattern may be made before the display is actually
`turned on, and the pattern re-scrambled if necessary until
`each code element spatial position has been changed from
`that previously used. Scrambling preferably is done between
`operations of the lock. but may be done at other intervals
`such as, by way of example. after each code element entry.
`Also, the range of displayable code element patterns does
`not have to include all theoretically possible displayable
`patterns, but instead may merely be a subset of the full range
`of possibilities.
`Now referring to FIG. 6, a still further embodiment of the
`invention may be seen. This embodiment is the same in
`concept as the embodiment hereinbefore described. In
`particular, it includes an armored case 22a having a micro(cid:173)
`phone 24 and a plurality of displays. each for displaying any
`one of the ten digits O through 9. However. unlike the
`previously described embodiment, the embodiment shown
`in FIG. 6 has the capability of only displaying four code
`elements at a time, again in a two dimensional spatial
`arrangement. Thus. the number of code elements which may
`be displayed at any one time is substantially less than the
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`5,668,929
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`7
`total population of possible code elements. However, as
`before, a valid code is determined by a user reciting the code
`element digits in a sequence corresponding to a valid code
`element spatial position sequence. Accordingly, in this
`embodiment it doesn't matter what four of the ten digits are
`displayed for any code element spatial position input, or
`whether the four displayed code elements are re-selected
`between each code element spatial position input, though it
`is of course important that as a minimum, the code elements
`displayed be re-selected or at least scrambled between
`successive operations of the lock. Assuming codes are not
`personalized so that each user of the lock will use the same
`code, any code element entry will have one chance in four
`of being correct. Thus for a five spatial position sequence
`code, there would be 1 chance in 1,024 that random opera(cid:173)
`tion of the lock would be successful, or for a 7 digit code 1
`chance in 16.384 for a random input of a sequence of the
`seven code element positions would be successful. Thus, in
`general, unless a particularly long code element spatial
`position sequence were used, an embodiment such as shown
`in FIG. 6 would generally be of lesser security and probably
`not as well suited to the use of personalized codes than the
`hereinbefore described embodiment, although there are
`other advantages useful in certain applications. In particular,
`it should be less expensive, it should be easier for children
`to use, for a given total display area the code elements
`displayed may be larger for sight impaired people, or
`alternatively the total display area may be made consider(cid:173)
`ably smaller, not only making the same less expensive but
`also making it easier to shield the display from view by an
`interloper when the lock is being used. In that regard, the
`display for an embodiment such as that shown in FIG. 6
`(though in the other embodiments also) could easily be a
`small single display device such as by way of example, a
`back lighted liquid crystal display, with the entire display
`area shrouded and/or baffled to prevent viewing from the
`side. Normal viewing of the display only by the user can also
`be provided by using a peep hole for viewing a small display
`within the unit, perhaps through a magnifying eyepiece.
`In the embodiments herein before described, a two(cid:173)
`dimensional spatial pattern of code elements has been used.
`In the embodiment of FIG. 7 however, a linear or one(cid:173)
`dimensional array of code elements is used, the security
`device otherwise functioning as herein before described,
`particularly with respect to the embodiment of FIG. 6. While
`the one-dimensional spatial display would be difficult to
`package and use if ten code element positions were dis(cid:173)
`played at one time, if the number of code elements displayed
`at one time is relatively low, such as three in the embodiment
`of FIG. 7, the display may be a short one line display quite
`small and easily shrouded and/or baffled to provide the
`highly limited viewing angle. Obviously of course, such a
`linear display of code elements may be arranged vertically
`rather than horizontally, the vertical arrangement perhaps
`being even easier to limit in sidewise viewing angle by 55
`baffles as illustrated in FIG. 8. Of course in any embodiment
`of the present invention, other code element forms may be
`used if desired, such as by way of example, letters as
`illustrated in FIG. 11, graphic symbols such as shown in
`FIG. 12 which could be selected for particular ease in 60
`remembering by children and/or distinctiveness with respect
`to each other for particular ease of speech recognition, or
`even mixtures of letters, numbers and symbols such as in
`FIG. 13.
`Now referring to FIG. 9, a block diagram for the elec- 65
`tronic control of the present invention may be seen. As
`shown therein, microphone 24 provides a microphone signal
`
`8
`to an analog preprocessing circuit 52 which in turn is
`coupled to analog to digital (AID) converters 54 coupled to
`the bus of a microcomputer comprising a central processing
`(CPU) unit 56, random access memory (RAM) 58 and read
`5 only memory (ROM) 60, the microcomputer itself control(cid:173)
`ling the display 48. The analog preprocessi