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BACKGROUND OF THE INVENTION
It is known in the art to record a series of picture signals on a moving
magnetic tape and subsequently reproduce the picture signals at
essentially the same rate of recording to create a motion picture on a
video or television screen for visual observation. My patent application
Ser. No. 688,348, now abandoned, describes means for recording a video
signal of a single frame or screen sweep of the video scanning beam of a
camera or flying spot scanner. The video signal may be reproduced
thereafter and used to provide a still image picture on a video monitor
screen.
In U.S. Pat. No. 2,494,441, a method and an apparatus are disclosed for
obtaining the average or mean dimensions of small particles by counting
pulses generated in scanning a large number of small particles. In this
particular disclosure, it is necessary to mathematically calculate the
average or mean particle size and possibly the area covered by the
particles by using mathematical formulas. However, it is not possible to
specifically pick out a particular particle and measure its size or area
directly by using this prior art method and apparatus.
In U.S. Pat. No. 2,731,202, an apparatus is provided for counting the
number of particles appearing in a field of view against a background
contrasting in appearance with the particles. In this particular prior art
structure, a beam is impinged on the viewing field. Whenever there is a
change in the beam intensity, an electrical pulse is produced and counted.
That is, this prior art method and apparatus merely provides a simple
counting technique. There is absolutely no disclosure for digitizing the
image on the field of view to provide its location or the specific
dimensions thereof.
PURPOSE OF THE INVENTION
It is a primary object of this invention to provide a new and improved
automatic scanning and inspection apparatus.
Another object is to provide an automatic image field scanning apparatus
which is capable of automatically determining various characteristics of
the field being scanned or any predetermined portion thereof.
Another object is to provide an automatic inspection apparatus employing
one or more electron beams which apparatus is highly versatile and may be
used to perform a plurality of different scanning and inspection functions
without major modification to said apparatus.
A further object is to provide an automatic inspection apparatus including
beam scanning means for analyzing an image or field with said apparatus
capable of providing the results of scanning directly in coded form which
may be used by a computer.
Another object is to provide an automatic inspection apparatus for
automatically comparing or measuring a plurality of different dimensions
in an image field in a substantially shorter time interval than possible
by conventional inspection means.
Another object is to provide an improved means for electrically controlling
and selecting portions of an image field being inspected.
A still further object is to provide an improved electro-optical comparator
means employing beam scanning which does not require masking an image
field for effecting selective area scanning.
Another object is to provide an automatic inspection apparatus employing
beam scanning to determine dimensions and other characteristics of
articles of manufacture, whereby both the work and the beam scanning means
may be positionable by numerically controlled manipulators to present
predetermined portions of the articles to be inspected in the field of the
beam scanning means.
Another object is to provide automatic inspection beam scanning means for
scanning and inspecting a plurality of different image fields which may
comprise different areas of a workpiece.
Still another object is to provide means whereby a video picture signal may
be used to effect automatic quality control by the investigation of part
of said signal.
Another object is to provide a means for effecting automatic measurement
and quality control functions using two video picture signals. One is a
standard signal of known characteristic and the other is a sample or test
signal whereby all or parts of said signals are investigated and compared
by their simultaneous reproduction from a magnetic recording medium on
which they are recorded in a predetermined relative position.
Another object is to provide automatic means for reproducing a specific or
predetermined part or parts of a video picture signal for computing,
measurement or control purposes.
Another object is to provide automatic means for reproducing that part of a
video signal derived during the scanning of a specific area of a total
image field without the need to control the scanning beam of a video
scanning device.
Another object is to provide means for operating on video picture signals
and for modifying or changing specific portions of said signals whereby
the altered picture signal may be used to produce a video image or still
picture of modified image characteristics.
Another object is to provide a recording arrangement including analog
signals with digital pulse code signals recorded adjacent thereto for
identifying portions of said signals.
Another object is to provide automatic scanning and control means for
effecting measurement or inspection of an article of manufacture on a
production line for determining the dimensional or other physical
characteristics thereof.
Another object is to provide new and improved apparatus which may be used
to effect various inspection, control and digitizing functions.
Another object is to provide automatic apparatus for measuring an object or
surface including means for selectively measuring predetermined parts of
said object and for providing information in code form resulting from said
measurement which code may be utilized by a digital computer.
SUMMARY OF THE INVENTION
As described herein, an apparatus and a method are provided for digitizing
an image field. Code signals such as binary digital signals are generated
when the image field is scanned. The code signals indicate information
such as location of a line, the border of an object, the distance between
lines or borders, and areas. It would be possible to indicate information
related to volumes when appropriate mechanism is provided to scan in all
directions.
In one embodiment of this invention, a beam scanning apparatus includes an
electron beam which may be moved relative to a workpiece or image field to
provide information or a picture field from a code signal which has been
generated within the beam scanning apparatus. The apparatus further
includes means for analyzing the code signal to determine certain
characteristics of the image field such as the presence or absence of
images or image portions such as components of an assembly, flaws, or
other objects in the field, and the location and/or dimension thereof.
The apparatus of this invention is applicable for the inspection of
articles of manufacture. In addition, the apparatus may be used to
automatically analyze a field such as a drawing, photograph, map or
electronic picture as found on an oscilloscope. The analysis provides a
determination of the degree of certain characteristics of the field such
as light or dark areas which are indicative of certain known conditions.
Such characteristics are obtainable in code form in one aspect of the
invention and are thus capable of being analyzed by a computer or other
device. In another form of the invention, apparatus is presented for
automatically analyzing a changing condition in an image field.
In another specific embodiment, the digitizing can be effected either
automatically by a flying spot scanner or by a cathode ray tube or by
manual techniques which currently use a photoelectric cell or some other
form of sensing device. Therefore, the digitizing may be accomplished
either in constant speed or variable speed. That is, it can be done either
by timing of a constant speed scanner or in proportion to the degree of
movement of an allied digital converter such as a wheel having codes
associated therewith.
DEFINITION OF TERMS
Components and known circuits provided herein bear the following general
alphabetical notations in the various drawings. Unless otherwise noted,
the circuits and components referred to herein and illustrated in block
notation are standard circuits which are known in the art. General titles,
notations or terms such as "multi-circuit timer or controller",
"computer", "computing circuit", "recorder and/or computer", "signal
analyzer", "analog/digital converter", "clipper", "alarm", "storage tube",
and "binary adder", are well known components and perform specific
functions known in the prior art. The various components referred to,
while they perform their normal functions, have been combined together in
a new and unobvious way to effectuate a new and unobvious result not known
in the prior art before the effective filing date of the present
application. Such prior art patents as U.S. Pat. Nos. 2,494,441;
2,731,202; 2,749,034; 3,081,379; 3,098,119; 3,239,602; 3,539,715;
2,429,228; 2,726,038; 2,754,059; 2,735,082; 3,146,343; 3,027,082;
2,979,568; 2,536,506; 2,615,306; and 2,729,771 are exemplary of the manner
in which such terminology is acceptable in the prior art to fully disclose
the inventions claimed therein. As shown in these prior art patents, all
of the terminology referred to in the instant case is clearly known in the
prior art and thereby provides the skilled artisan sufficient disclosure
to effectuate the invention of the present disclosure. Where a hyphen (-)
follows the letter, it is assumed that a multiplicity of the devices or
circuits are provided in the disclosure.
A- amplifier, such as a reproduction amplifier for amplifying signals
reproduced by an associated magnetic reproduction transducer or pickup
head PU.
Ra- recording amplifier, used to record pulse or video picture signals on a
magnetic recording member.
An- a logical AND switching circuit which will produce an output signal
when, and only when, signals are present at all inputs to said circuit.
Cl- a vacuum tube or semi-conductor clipping circuit, preferably a video
clipper operating at a desired clipping level.
Cm,cm'- a schmitt cathode coupled multi-vibrator circuit, which comprises a
cathode coupled multivibrator with an associated signal inverter at the
output of the multivibrator. This circuit will produce a pulse output when
the leading edge of an elongated pulse appears at said circuit and a
second pulse output when the trailing edge of said pulse reaches said
circuit.
D- delay line or time delay relay of required time constant. If a signal
such as a video picture signal is to be delayed, D signifies a delay line.
If, ifp- a scanning image field where video beam scanning is employed for
inspection.
N- a normally closed, monostable switch or logical NOT switching circuit
which will open and break a circuit when a signal is present at its
switching input. It may be a vacuum tube, semiconductor or
electro-mechanical device or any other logical circuits or gates.
Or- a logical OR switching circuit adapted to pass a signal from any of a
multiple of inputs over a single output circuit.
Ff- a flip-flop switch, electro-mechanical, vacuum tube or semi-conductor
circuit. A bi-stable switch adapted to: (a) switch an input signal from
one of two input circuits to one of two output circuits, (b) switch a
signal from a single input circuit over one of two outputs depending on
the described application. The flip-flop switch may have two or three
switching inputs depending on the application, a complement input C which,
when energized, switches a single input from one output to the other
and/or two inputs, each of which, when energized, switches the flip-flop
to its respective output.
Pb- a picture signal, preferably derived from beam scanning a fixed image
field IF. The signal may be amplitude modulated or frequency modulated and
may be the output of a conventional television scanning camera, flying
spot scaner or the like. It may be a continuous signal or may consist of a
multitude of short pulses depending on the type of scanning and signal
formation employed.
The PB signal may also be derived from the output of a fixed photo
multiplier tube with the image or object being scanned, being moved to
provide variations in said signal. For some applications, the PB signal
may be any analog signal derived from scanning, an analog or digital
computer or other computing device.
Pc- pulse code number. This may be any type of code (binary digit, decimal,
etc.) recorded either longitudinally along a single channel of a magnetic
recording member or recorded laterally along a single channel of a
magnetic recording member or laterally along a fixed path or line across
multiple channels of said recording member, there being code positions
where said code line crosses each recording channel which either (a)
contains or does not contain a pulse recording or (b) contains a positive
pulse recording or a negative pulse recording depending on the design of
the digital computing or switching apparatus to which the reproduced code
is transmitted. If recorded along a lateral line of the recording member,
the code PC may be reproduced at a specific point in the reproduction of
one or more picture or analog signals adjacent thereto and may be used to
effect a specific switching action when reproduced to affect a specific
section or length of the associated picture signal(s).
Sw-a, limit switch.
Sc,cs-a signal or signals preferably recorded in positions on a magnetic
recording member to be reproduced simultaneously with a specific section
of another picture or analog signal and used for gating or control
purposes.
St- refers to a video storage tube or storage device having a writing input
WI for recording a picture signal on the storage element of said tube and
an output RI, which, when a second input R2 is pulsed or energized, passes
a picture signal derived from the scanning of the read beam of said tube.
Cl- refers to a clipping circuit adjusted to clip at a specific clipping
level. A diode, triode or other clipper such as used in video clipping.
If, ifp- refers to an image or object field being scanned to produce a
picture signal. The field in the optical system of a conventional or
special television scanning camera. The field may also be the screen of an
optical comparator or projection microscope having a video scanning camera
or flying spot scanner focused and positioned relative thereto in a
predetermined manner. The image or images in said field may be any optical
or radiation phenomenon which provides an area or areas therein of
different radiation or light characteristic relative to other areas so
that, in scanning across said different areas, the resulting picture
signal will change sufficiently to permit a measurement or measurements to
be made by electrically noting said changes or differences. The field may
also comprise a map, photograph, X-ray image or pattern, etc.
All of the above terms indicating various components may be interconnected
to accomplish their desired results by the skilled artisan. The drawings
discussed herein below along with the description of the specific
embodiments clearly give guidance to the skilled artisan to select and
interconnect each of the prior art devices to perform the desired
operations and effectuate the new and unobvious results as set forth
herein.
BRIEF DESCRIPTION OF DRAWINGS
The various electrical circuits used herein for performing the described
measurement, comparison and indicating functions are illustrated in block
diagram notation for the purposes of simplifying the descriptions and
drawings.
The following assumptions are also made regarding the circuitry to simplify
drawings and descriptions:
In the diagrams, where junctions are illustrated between two or more
circuits which are electrically connected at said junction with a further
single circuit, it is assumed that a logical OR circuit is employed at
said junction.
Where a single circuit extends from a junction to two or more circuits, it
is assumed that either a single input, multi-output transformer is
provided at said junction or said output circuits are resistance balanced
permitting any input signal to travel over both of said outputs.
Wherever circuits which require a power source, such as switching or
logical circuits, gates, clipping circuits, multivibrators, servo motors,
controls, amplifiers, transducers, are provided, it is assumed that a
source of the correct electrical power or potential is provided for said
circuits. Power is also assumed to be provided on the correct side of all
gates and relays where needed.
Various automatic measurement and comparison scanning techniques are
provided herein whereby a picture signal, derived from photoelectric, or
video scanning an image field or part of a field, is recorded on a
magnetic recording member such as a magnetic tape along a predetermined
length of said tape and in predetermined positions relative to other
signals used for gating and control. When reproduced together, said other
signals may be used to effect one or more predetermined functions relative
to said picture signal.
The method of recording all signals in predetermined relative positions on
a recording member and then reproducing and using said signals in one or
more manners described herein has a number of advantages including the
provision of a record which may be rechecked, if necessary, or otherwise
monitored. However, in the embodiments provided, it is not necessary to
record the video or picture signal on the recording member if means are
provided for presenting said picture signal in the respective measurement
or control circuit at a predetermined time in relation to said other
signals. For many of the functions described, particularly those where it
is only necessary to measure or compare images, a picture signal may be
passed directly from a video storage tube or other photoelectric scanning
device to the reproduction amplifier through which the reproduced signal
passes. However, functions such as record keeping may require that the
picture signal be recorded; hence recording arrangements are illustrated.
In the various magnetic recording arrangements and apparatus provided
herein, picture signals are shown recorded on a magnetic recording member
which also has other signals recorded thereon in predetermined positional
relationship to said picture signals. The recording member is illustrated
as an elongated flexible magnetic tape or the developed surface of a
magnetic disc or drum. While not illustrated, it is assumed that known
means are provided for driving the tape or drum at constant speed past
magnetic reproduction apparatus when constant speed is a requisite for the
desired measurement. For example, when an automatic timing circuit is
utilized to effect a measurement between two predetermined points in the
picture signal, the timing device and the drive for the tape must be
synchronized to start at predetermined times and operate at predetermined
rates. If the magnetic recording member is driven at a predetermined
constant speed, and if the timing device operates at a predetermined
constant rate and is started at an instant determined by the time of
reproduction of one or more signals on said magnetic recording member,
then a particular reading or value of the timing device may be converted
to a lineal distance or a coordinate in the field which was scanned to
produce said picture signal.
The above objects and other advantages will appear in the following
description and appended claims, reference being made to the accompanying
drawings forming a part of the specification wherein like reference
characters designate corresponding parts in the several views.
FIG. 1 illustrates a portion of a recording member and an arrangement of
picture signals and control or gating signals provided thereon in
predetermined relative positions;
FIG. 1A illustrates a portion of a multi-track recording member having
plural picture signals recorded adjacent each other and associated control
or gating signals tandemly aligned with said picture signals;
FIG. 1B illustrates a portion of a multi-track recording member containing
both picture and code signals recorded on different tracks thereof and
also illustrates in block diagram notation, gating and computing circuitry
for utilizing reproductions of recordings;
FIG. 1B' is a circuit diagram showing details of part of the computing
circuitry of FIG. 1B;
FIG. 1C illustrates a portion of a recording member containing picture
signals and controls and circuitry provided in the output of the
reproduction transducers which scan said recording member;
FIG. 2 illustrates a portion of a multi-track recording member having
signals of predetermined duration or length recorded thereon is
predetermined positions relative to recorded picture signals for
indicating, when reproduced simultaneously with said picture signals,
dimensional ranges of the physical phenomenon or objects scanned to
generate said picture signals;
FIG. 3 illustrates a recording and reproduction arrangement whereby control
means are provided for blanking all but predetermined or particular
portions of one or more picture signals so that the remaining portion or
portions of said picture signals may be analyzed without interference from
the other portions;
FIG. 4 illustrates a recording and reproduction arrangement for operating
on a picture or analog signal in a manner similar to that illustrated in
FIG. 3 to effect one or more dimensional measurements or control
functions;
FIG. 4' is a fragmentary view of a scanning field illustrating the physical
significance of certain of the signals recorded on the recording member of
FIG. 4;
FIG. 4A illustrates a circuit applicable as a replacement for a portion of
the circuit of FIG. 4;
FIG. 4B illustrates a digital code generator or clock applicable to the
circuitry of FIG. 4 to effect measurement functions;
FIG. 5 illustrates a recording arrangement with predetermined positioned
sync and gating signals;
FIG. 6 illustrates the recording arrangement of FIG. 5 and circuit
components utilizing the signals provided thereon;
FIG. 7 illustrates a modified form of the recording arrangement and circuit
components of FIGS. 5 and 6;
FIG. 8 illustrates a recording arrangement and a reproduction circuit
diagram utilizable for effecting automatic dimensional measurement;
FIG. 8' illustrates a scanning field showing physical aspects of the
signals recorded in FIG. 8;
FIG. 9 illustrates a recording arrangement and reproduction circuitry
therefore applicable for measuring the various dimensions of distances in
an image field and providing said measurements as coded signals;
FIG. 10 illustrates a clipping level adjustment means applicable to part of
the apparatus of FIG. 9;
FIG. 11 is a more detailed view of a portion of FIG. 10;
FIG. 12 is a more detailed view of a portion of FIG. 9;
FIG. 13 is a perspective view of a scanning station utilized to provide
signals which are applicable to the recording and measurement arrangements
illustrated in the other drawings;
FIG. 14 is a plan view of FIG. 13, which view also illustrates recording
and dimensional measuring components;
FIG. 15 is a schematic diagram showing a circuit employing a summing
amplifier to generate pulse signals;
FIG. 16 is an isometric view of an inspection station employing means for
prepositioning both a scanning apparatus and a workpiece;
FIG. 17 is a diagram of control apparatus for the apparatus of FIG. 16 and
also illustrates means for recording and analyzing the results obtained by
scanning;
FIG. 18 shows another control arrangement applicable to the apparatus of
FIG. 16;
FIG. 19 shows an automatic scanning system having a scanner which is
positionally controllable to continuously scan different image fields and
includes means for indicating when changes occur in said image field; and
FIG. 20 shows a scanning arrangement employing a plurality of different
scanners each adapted to scan a different image field or phenomenon.
DESCRIPTION OF SPECIFIC EMBODIMENTS
The video information signals recorded on the magnetic recording mediums
illustrated in FIGS. 1 through 9 may be derived by using a television
scanning system and the components as shown, for example, in FIG. 14.
A number of recording, reproduction, scanning and comparison measurement,
counting, control and computing functions are described herein.
Additionally, an apparatus utilizes a video picture signal derived by
electron beam or flying spot scanning of an object or image field or a
video storage tube surface.
For most of the above functions, the picture signal or signals are recorded
in a fixed or predetermined position on a magnetic recording member such
as a magnetic tape or drum and relative to one or more control and/or
gating signals which will be denoted by the notations SC or CS. These
control signals are specified as constant amplitude pulse signals of a
short or predetermined duration. However, they may also be of variable
amplitude and/or frequency depending upon the type of operation or
function controlled thereby.
One technique comprises the scanning of an image or optical field such as a
predetermined area of a surface of a workpiece or assembly, or an image
field in which a portion thereof contains an object or plurality of
objects or areas having an optical characteristic which is discernible
from the characteristic of the surrounding field or background. For
example, the image may have different color or light characteristics which
investigation involves the analyzing of a length or lengths of the video
picture signal produced when the image or optical field is scanned by a
video camera or flying spot scanner.
If automatic scanning or comparison measurement using a change in a portion
of a video signal is to be employed for measurement or analysis of the
optical characteristics of the field from which the signal was derived,
then there is a requisite for such measurement. If it is to be meaningful,
the area, object or other phenomenon in the field being scanned must be at
a known distance from the scanning camera, optical system or the flying
spot scanner so that its scanned area will be to a predetermined scale in
the image field.
The attitude of the object or plane being scanned must also be fixed or
predetermined relative to the axis of the video scanning device. A plane,
point or area of the object should also be known or referenced in position
in the field being scanned. The requirement for any automatic measurement
is that a base or benchmark be established. The measurement or comparison
is effected in this invention by a scanning means which is utilized to
indicate the existence of an area, line or plane in the field being
scanned. Therefore, the above mentioned scale, alignment and positional
requisites must exist to a predetermined degree or tolerance in order to
attain a predetermined degree of precision in the measurement. It is thus
assumed that where dimensional measurement, comparative image analysis or
other investigations involving the scanning and analysis of a specific
area or areas of the total field are desired, the object, surface, or area
being scanned is prepositioned, aligned and provided at a predetermined
scale in the scanning field. For the automatic and rapid investigation of
multiple articles or assemblies by this method, a jig, fixture, platform
or other form of prepositioning stops may be provided to preposition the
articles at a fixed distance and attitude relative to the video scanning
device. Preferably at least one surface area or point of said article is
at a predetermined point, plane or position in space.
The following physical conditions may be measured, indicated or compared by
means of the automatic measurement apparatus provided herein:
(1) Indication of the position of a line, point, border of a specified
area, or a specified area in a given image field. This may be provided as
a coded signal or series of coded signals which are indicative of said
position or positions from a base point or line in the field or at a
specified distance from the field.
(2) Determination if the point, line or area is positioned in a
predetermined area or position in said field, and if not within limits,
how far the image falls or is positioned away from the predetermined
position.
(3) Determination if the point, line or area in the field being scanned
falls within a specified distance or region such as a tolerance range, one
or either side of a specified position.
(4) Determination in which of several specified regions in an image field
being scanned, each of which encompasses a different area either or both
sides of a specified position or area in said field, a point, line or area
falls. This function pertains to automatic sorting operations.
(5) Determination if a predetermined image exists or does not exist in a
specified area of an image field. If so, determination also as to how much
or to what extent the area falls in the specified area. This function
pertains to inspection functions to determine if image conditions exist
such as surface defects, markings, assemblies, or internal detects whereby
X-rays are used to provide the image.
(6) The measurement of the dimension or dimensions of an image in a field
by scanning part of said image at a constant scanning rate and timing the
scanning from one point in its travel across an image to another.
An erasible recording member, generally designated 10, may be a magnetic
tape or the developed surface of a magnetic recording drum, showing signal
arrangements thereon which are basic to this invention. The lateral and
longitudinal dimensions of the signal recording channels or areas
illustrated are not necessarily to scale or of equal scale and merely
illustrate the relative positions of the various signals on the recording
member so that their coacting functions may be described.
In all the figures illustrating relative signal areas, one of several
recording and reproduction systems may be provided whereby, while the
total recording pattern may vary, the positions of the various coacting
recordings relative to each other will essentially remain the same to
permit the same functions to be accomplished in one recording system as in
the other. For example, if the magnetic recording tape or drum is moved
relative to one or more recording heads which remain stationary, then a
series of parallel areas or tracks will be traced by the heads as
illustrated in FIG. 1. However, if the recording heads are driven in a
rotary path and sweep across the recording medium as the latter moves in a
fixed path relative to the rotational axis of said heads, then a series of
recording areas oblique to the longitudinal axis of the tape will be
traced thereon by the heads. The end of each oblique recording channel
area or head sweep will be continued further along the tape as the
beginning of a new oblique trace. Thus, any video and control signal
recording arrangements illustrated in one figure as provided on recording
areas or channels which extend parallel to the longitudinal axis of the
recording medium or tape, may also be provided on the oblique, repeating
recording areas of others of said drawings such as FIG. 5 if the same
relative positioning of said adjacent signals is maintained in the oblique
recording.
More specifically, referring to FIG. 1, a sync signal S1 and a picture
signal PB1 are recorded on multiple side by side recording areas of the
recording member 10. Each of the signals S1 and PB1 is recorded on a
separate channel thereof in a predetermined position with respect to the
other channels. The sync signal S1 is recorded on a first channel or track
C1 which indicates and may have been used to effect the precise
positioning of the picture signal PB1. The picture signal PB1 is derived
from beam scanning of the image field such as a video signal. The field
may or may not contain the frame blanking signal component. The picture
signal PB1 is shown recorded on a second channel C2. The picture signal
PB1 may be a recording of the signal output of a video scanning device
such as a video camera employing a vidicon, iconoscope or other scanning
tube or a flying spot scanner.
If it is desired to provide a visual display of the PB1 signal at some time
after its reproduction from 10, the duration and character of the PB1
signal is preferably such that it may be used when reproduced therefrom to
modulate the write beam of a video picture or storage tube. In my
copending application, Ser. No. 688,348 filed in 1957, the output signal
of a video camera or storage tube equivalent to the signal derived from
the video camera scanning read-beam is recorded during a single frame or
screen sweep either in an image storage tube or on a moving recording
member. Thereafter, the signal is reproduced at video frequency and used
to modulate the picture generating write-beam of a video monitor-screen.
The PB1 signal of FIG. 1, if intended to later reproduce a visual image on
a monitor screen, is thus preferably an image, single frame video picture
signal. The beginning of the picture signal is positioned adjacent to or
in predetermined relation to sync signal S1 such that sync signal S1 may
be used to control the reproduction of the picture signal PB1. For faster
scanning, the start of the picture signal may be defined as a
predetermined point occurring at or after the frame vertical sync signal
appears when the socalled read beam starts its frame sweep.
In the inter-laced scanning system, each complete sweep of the camera
scanning beam is referred to as a "field" sweep and two of such image
fields make up an image "frame". As stated, the PB1 signal preferably has
provided therewith the associated frame blanking signal so that it may be
used to effect the production of a video image, if necessary, for display
purposes. For specific computing or operational functions, it may be
desirable to merely compare part of the PB1 signal with another signal
whereby only part of a single frame signal need necessarily be recorded
and the blanking component of said signal may be eliminated. The sync
signal S1 may be used as a trigger signal recorded on a predetermined
position of member 10 and used thereafter to trigger or otherwise effect
the recording of the PB1 signal on a predetermined recording area or
channel of member 10. If the PB1 signal is recorded at random on member
10, sync signal S1 may be used as an indicator of the position of the PB1
signal and of another signal or signals also recorded thereon.
A third channel or band recording area C3 parallel to bands C1 and C2,
contains the necessary video horizontal line sync signals HS. The sync
signals HS are recorded in a predetermined position relative to PB1 for
the correct horizontal deflection and synchronization of the picture and
blanking signal PB1 to effect the production of a video image.
A fourth channel C4 runs parallel to the other channels and contains the
associated vertical synchronization signal VS1 for vertical line and frame
synchronization of the picture signal PB1. The latter two signals HS and
VS1 are optionally provided in the event that it is desired to reproduce
the PB1 signal as a picture on a video screen for monitoring or other
purposes.
One or more additional recording channels or areas C5, C6, C7, C8, C9 and
C10 preferably extend in a direction parallel to and are adjacent to those
channels described hereinabove. The channels C1, C2, etc. contain one or
more operational gating or command signals CS1, CS2, etc. which may be
either pulse or analog signals. The command signals CS1, CS2, etc. are
preferably provided in predetermined fixed positions relative to the
picture signal PB1 located on channel C2 to be reproduced therewith and
are used to modify, gate or operatively coact with the video signal PB1.
While the various control signal or signals CS1, CS2, etc. may be recorded
at any time on the recording medium 10, if their precise position relative
to the video signals is an important factor, their recordation may be
triggered by the synchronizing signal S1 which indicates the position of
the video signals. If precisely relative to sync signal S1, the CS signals
will also be precisely positioned relative to the video signal or signals
and may be used to effect one or more operative or measurement functions
on or in coaction with the PB1 signal.
The command signal or signals CS1, CS2, etc. may be provided in one or more
forms. A single pulse, such as CS1, may be recorded on a single channel of
member 10 and positioned adjacent a specific length of the video signal or
signals. When reproduced therefrom as said member 10 moves relative to
respective reproduction heads, the pulse signal CS1 may be used, for
example, to gate an adjacent similar length of the video signal over an
output circuit for scanning, modifying, measuring, clipping or otherwise
operating on or cooperating with said video signal. Thus, the position as
well as the length of the pulse signal CS1 will determine what section and
length of the video signal will be gated or otherwise operated on. The
other operations controlled by CS1 may include magnetic erasure,
attenuation, amplification or other modifications to said video signal
adjacent or behind said pulse signal on channel C5.
While the CS1 signal may be a constant amplitude signal or pulse of any
desired length, it may also be an analog signal of varying amplitude
and/or frequency which is utilized to perform a more complex function on a
particular section or sections of the video signal.
A series of other command or control signals CS2, CS4, CS5 and CSC are
laterally aligned bit pulses. Each pulse is on a different channel and
capable of being simultaneously reproduced therefrom by respective
magnetic heads which are preferably aligned and scan a separate track or
area referred to by the notations C6 to C10. The series of pulses may be
in the arrangement of a digital code PC, such as a binary code, and may be
used to effect circuit selection, computing and/or switching functions.
Circuit selection functions may be operative to (a) affect a specific
section or length of the video signal, (b) select a specific section or
sections of said video signal for reproduction, (c) adjust or otherwise
affect one or more electrical components or circuits in the output of the
reproduction head or heads of the video signal or (d) select one of a
multiple number of circuits through which part or parts of said video
signal may be gated for measurement, inspection or scanning functions to
be performed thereon.
While the CS2, CS3, CS4, etc. signals illustrated in FIG. 1 are shown
aligned laterally across the medium or tape 10 for simultaneous
reproduction by aligned magnetic heads, they may be provided in any
positional arrangement which will be determined by the positioning of the
magnetic reproduction heads and the required function of said signals. The
signals CS2, etc. may be formed as a pulse chain by providing the
necessary delay lines or elements in the output circuits of the respective
reproduction heads. Furthermore, a pulse chain for computing and (or)
control or switching purposes may be provided on a single track adjacent
the video signal in the form of the appropriate tandem pulse signals or
multiple pulse chains may be provided thereon. Preferably, the pulse
chains are sufficiently in advance of the video signal or a section of the
video signal which it is to affect or gate, to permit a switching,
computing or shaft positioning action to take place prior to the
reproduction of the desired section of said video signal. The position of
said recorded signal or signals on member 10, will also be a function of
the relative positions of the various reproduction heads.
A code or bit number PC' is shown as a series of tandem pulses on the
channel C10 and having the binary value 1110101. The code PC' is provided
as a series recording to illustrate that such a means of recording
numerical information may be used with an adjacent analog or picture
signal to be reproduced prior to, during or after the reproduction of said
picture signal for effecting computing and/or control operations to be
performed on or in coaction with the reproduction of said picture or
analog signal, or in relation to at least part of said signal. If the
series code PC' is utilized for computing and control purposes adjacent a
picture signal PB, then still another channel (not shown) is preferably
provided with a series of equi-spaced, equiduration pulses recorded
thereon at preferably the interval of the pulses of PC' to act as a clock
when reproduced simultaneously therefrom thus simplifying digital
operations in a switching circuit or computer using said pulse code.
The recording of the picture signal PB and the associated sync signals on
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