Note: Descriptions are shown in the official language in which they were submitted.
JPD:jak Al 9/16/7~ 19151-~
:~074(~0~
Frequent need arises for bringing about relative
synchronization between different sources of information.
For example, it often happens tnat a TV program source is,
say, one-half field later than another, and/or the time
relationship may drift slowly. At present there is no way
to correct the difference so that different sources can be
used on the same program. Moreover, there are several TV
standards in the world. U.S. and Japan use 525 lines, 60
fields per second, the NTSC standard. In Europe, a common
system is the 625 lines, 50 fields system of PAL. A simple
system does not exist for converting from one frequency
standard to another.
Also, systems employed for delayed broadcast or
"stop action" can be relatively complicated and costly, as
when magnetic recording and playback apparatus is employed.
Moreover, with magnetic recording and playback, generally
a minimum delay is required between recording and playback
so that the respective recording and playback heads can be
physically accommodated along the magnetic recording medium.
According to the present invention, first and
second optical means are disposed relative to a record
medium suitable for receiving and recording electromagnetic
information. The first optical means records the informa-
tion via a first optical path, and the second optical means
reads the recorded information via a second optical path.
These optical means have a predetermined simultaneous rela-
tionship with respect to the recording medium, and means are
employed for coordinating the first and second optical means
for simultaneous operation. Thus, the second optical means
may read out information at a predetermined delayed time
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JPD:jak Al 9/16/75 19151-~
~4~3051
after recording takes place, or means may provide relative
movement between the first and second optical means whereby
the reading rate is different from the recording rate.
The firs~ and second optical means suitably com-
prise optical scanners simultaneously disposed with respect
to a recording medium which is recorded upon by a recording
light means and whlch rapidly records the information for
playback.
The optical scanners suitably produce tracks of
information across the moving recording medium wherein the
scanned information is broken into recording lines extend-
ing across the recording medium. Electronic means is suit-
ably provided for supplying an overscan gap between lines,
i.e. to and from the edge of the recording medium, wherein
data is compressed while recording into lines and then
expanded for readout at a predetermined rate.
It is therefore an object of the present inven-
tion to provide an improved system for delayed playback of
recorded information.
Another object of the present invention is to pro-
vide improved means for recording and playback OL informa-
tion at different rates.
A further object of the present invention is to
provide improved means for recording and delayed playback
of information wherein the relative delay can vary over
wide limits.
It is a further object of the present invention
to provide an improved system for transcoding between dif-
ferent coding standards.
~07'1(~
~.
A further object of the present invention is to provide an im-
proved system for delayed playback of information, and for "stop action" of
information.
Another object of the present invention is to provide an improved
system for indexing and editing recorded information.
A further object of the present invention is to provide an im-
proved system for recording information in recording lines having a scanning
gap therebetween wherein information is expanded for readout into a continuous
stream.
According to one aspect of the invention there is provided re-
cording and reproducing apparatus comprising: a record medium capable of re-
ceiving and recording electro-magnetic information, first optical means for
recording information along a track on said recording medium via a first
optical path from said first optical means, second optical means for reading
the recorded information along said track via a second optical path to said
second optical means, said first and second optical means having a pre-
determined simultaneous relationship with the same recording medium, and
means coordinating said first and second optical means for simultaneous opera-
tion, said second optical path having a predetermined position relative to the
first optical path to provide a predetermined delay at a given instant of
time in information read out relative to information recorded.
According to another aspect of the invention there is provided
apparatus for recording and reproducing information comprising: a record
medium responsive to electro-magnetic radiation, a first optical scanner for
scanning a first beam of electro-magnetic radiation along a track on said
record medium for recording information thereon, a second optical scanner in-
dependent from the first optical scanner and positioned along said recording
medium for scanning a second beam of electro-magnetic radiation along said
t~ack for ~eading information aPter sa~d first beam of electro-magnetic ra-
diat~on has recorded informationl mean~ for preduc~ng relative movement be-
tween `sa~d scanners and said record medium, and means coordinating said first
and second optical scanners for simultaneous operation.
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In accordance with a further aspect of the invention there is pro-
vided recording and reproducing apparatus comprising: a record medium cap-
able of receiving and recording information in a plurality of separated
tracks, means for recording and reproducing the information in said tracks,
input circuit means for receiving a substantially continuous flow of informa-
tion, and for separating the same into compressed segments corresponding to
said tracks for recording the same, and output circuit means for reading out
the information from said tracks and for expanding the same into a sub-
stan~.ially continuous stream.
In accordance with another aspect of the invention there is pro-
vided apparatus for reading a record, said apparatus comprising: a record
medium capable of receiving information in a plurality of separated tracks,
means for reproducing the information in said tracks including optical means
for successively reading said tracks with a finite time period between the
reading of desired contiguous information on one track and the reading of de-
sired contiguous information on the next track, and means for expanding the
information read from said tracks to produce a substantially continuous flow
of information.
According to a further aspect of the invention there is provided
recording apparatus comprising: a photographic record medium capable of re-
ceiving and recording information in a plurality of separated tracks extend-
ing substantially across said rec,ord medium in parallel raster fashion, means
for optically recording the information in said tracks substantially across
said record medium, and means for receiving a substantially continuous flow
of information, and for compressing the same into time compressed segments
corresponding to said tracks or recording the same.
The present invention, both as to organization and method of
operation, together with further advantages and objects thereof can best be
understood in reference to the ollowing description taken in connection with
the acc~mpan~lng drawlngs wherein l~ke reerence characters refer to like
elements.
Figure 1 is a schematic side view, partially in cross section, of
~ - 3a -
recording and playback apparatus according to the first embodiment of the
present invention;
Figure 2 is a plan view of the Figure 1 apparatus;
Figure 3 is a view of recording scanner according to the Figure 1
apparatus, the view being taken at 3-3 in Figure l;
Pigure 4 is a schematic view of an optical deflection device em-
ployed in the present invention; :
Figure 5 is side view, partly in cross section, of a recordingand playback apparatus according to another embodiment of the present
invention;
- 3b _
. -
JP~:jak A1 9/16/75 19151-~
4~ta~
Fig. 6 is a side view, partially in cross section,
of yet another embodiment of the recording and playback ap-
paratus according to the present invention;
Fig. 7 is a block diagram of electronic circuitry
suitably employed in recording information according to the
present invention;
Fig. 8 is a block diagram of electronic circuitry
for playback of information according to the present inven-
tion;
Fig. 9 is a diagram illustrating the wave form of
typical recorded information;
Fig. 10 is a plan view of a recording medium
according to the present invention;
Fig. 11 is a block diagram of an additional cir-
cuit which may be used in a television transcoding operation;
and
Fig. 12 is a schematic side view, partially in
cross section, of apparatus according to yet a further embo-
diment of the present invention.
Referring to the drawings and particularly to
Figs. 1 through 3, an apparatus according to the present
invention includes a first optical scanner 10 and a second
optical scanner 12 which are adapted to scan beams of elec-
tromagnetic energy, e.g. light beams, across a record med-
ium 14. A record medium 14 is suitably a tape unreeled
from reel 16, passing between capstan rollers 18, 20 and ~
22, 24 in the direction of the arrow, and received onto a -
pickup reel 26. Capstan rollers 18 and 22 are respectively
empowered by servo motors 28 and 30 (see Fiy. 2), and have
a contoured surface for "dishing" a record medium 14, as
Jl'u/~ 4j'`0/79 ~'L',2 ~-~
~LV74~0~
illustrated in Fig. 3, whereby the light beam from scanner
10 can be accurately focused upon the record medium.
The record medium should be self-developing. There
are several classes of pho-tosensitive materials that are
satisfactory, i.e., dry silver, free-radical, vesicular,
ther.nal destruction (melt or va~orize), and photochromic.
The dry silver and free-radical systems require a further
treatment of heat if a permanent record is desired. Hence,
for these materials a heating element (not shown) is
employed subsequent to recording by means of scanner 10.
The various rapid light recording media are known by
those skilled in the art.
Scanner 10 suitably conprises a metal cylinder 28
journaled in bearings 31 supported in turn by an outer
cylindrical body 32 which also supports motor coils 34.
Hence, the cylindrical body 28 forms the rotor of a motor
such as a synchronous hysteresis type.
Uæon one end of cylinder 28 is secured a head 36
which rotates and carries a plurality of objective lenses
38 around the forward periphery thereof. As illustrated in
Fig. 3, six evenly spaced objective lenses 38 may be
located at tlle forward end of head 36 and disposed in an
angular forward wall of the head for scanning across the -
record medium 14 as the cylinder 28 is rotated about its
axis which is parallel to the direction of motion of the
record medium 14.
The light for scanner 10 is provided by a laser
40 positioned axially forward of the scanner 10 and adapted
for projecting a beam of light 42 substantially along
the axis of the scanner through a modulator 44 to an optical
~: '
- 5 - ~
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JPD:jak Al 9/16/75 191~1-5
40~?S;
tube 46 which is suitably located partially within cylinder
28. The optical tube 46 includes lenses 48 and 50 and a
pinhole aperture 52 therebetween. Lens 50 directs light
from the pinhole upon a pyramidal shaped mirror 54 which is
secured to the forward end of head 36 and functions to dir-
ect the light to the lenses 38 in succession as head 36
rotates. Thus, since six objective lenses 38 are located
in head 36, pyramidal mirror 54 is formed with six facets,
each one of which successively reflects light to a lens 38
for scanning a light beam 55 across record medium 14.
The light beam is imaged to a narrow track across
the record medium 14. Thus, the recording track is about
one micron in width, and the spacing between track centers,
as the recording medium 14 is moved longitudinally, is
about three microns. The total length of track required
depends upon the bandwidth and recording format selected.
With a film having a width of approximately two inches,
about 4.5 inches of record medium per minute is required
for television recording or about eleven feet per thirty
minute period. A 1000 foot reel of record film would last
about two days. This recording density represents an im- -
provement of more than one hundred as compared with the
recording density for television information on magnetic
tape, for example.
The recording apparatus according to the present
invention generally contemplates digital recording of infor-
mation wherein modulator 44 is either in an on condition or
an off condition as controlled by a binary type input on
lead 56 coupled via amplifier 58 to the modulator. In such
case, the recording is from the type set forth in my U.S.
--6--
JPD:jak Al 9/16/75 19151-5
Patent ~o. 3,501,536 granted March 17, 1970, and entitled
"Analog to Digital to Optical Photographic Recording and
Playback System", wherein information is expressed in digi-
tal spots. However, the apparatus according to the present
invention may also suitably record analog information where-
in an analog input is received on lead 56.
According to this embodiment of the present inven-
tion, a second or reading scanner 12 is disposed along the
- record medium 14 for reading out the recorded information
at a variably preselected time after the same is recorded
on the medium. The second scanner 12 is substantially
identical to the recording scanner and includes a cylinder
60 journaled in bearings 62 secured to an outer cylindrical
member 64 which also supports motor coils 66. A head 68
supports pyramidal mirror 70 at the forward end thereof
for directing light through a plurality of objective lenses `~
72 positioned in a forward angular wall of the head. The
number of lenses 72 may be the same as the number of lenses
38 in the recording scanner, i.e. six, in the instance of
the particular example.
A playback laser 74 directs a beam of light
through an optical tube 76 disposed along the axis of scan- `
ner 12 and including lenses 78 and 80 and a pinhole aper-
ture 82 located therebetween. Lens 80 directs the beam
from the pinhole aperture to the pyramidal mirror 70 for
successively directing the light beam toward the particular
objective lens 72 which is tracing across the record medium
14.
In the case of tube 76, a further deflection de-
vice 84 is housed between the pinhole aperture 82 and lens
--7--
)74(~o~
80. This deflection device is further disclosed and claimedin my Canadian patent No. 1,040,908, effective October 24,
1978, and entitled "Optical Fiber Deflection Device". A
typical embodiment is illustrated herein in Fig. 4.
Light is directed from lens 78, Fig. 1, axially along
an optical fiber 86 which is shown in end view in Fig. 4.
It is desirable to deflect the optical fiber 86 in mutually
perpendicular directions indicated by arrows 88 and 90.
A first coil 92 is disposed upon a first magnetic metal
core, the ends of which form pole pieces 94 and 96 on
opposite sides of optical fiber 86. A further metal
magnetic core has pole pieces 98 and 100 located on either
side, the optical fiber, along a direction orthogonal to
the first set of pole pieces, while a coil 102 is disposed
around the second magnetic metal core. The optical fiber
86 is made of light transparent glass or plastic and is pro-
vided with coating of metal or other conducting material
which is electrically connected at one end by a lead wire
104 to a battery 106, and the opposite terminal which is
;ao grounded. The opposite end of the coating on the optical
fiber is also grounded so a current flows therealong.
First ends of the coils 92 and 102 are connected to a
tracking control 108 which controllably provides current
through the coils for deflecting the optical fiber 86 to
the desired extent. In this manner, the exact positioning
of the light beam passing through lenses 72 onto the record
``medium 14 can be controlled. Other deflection structures
are disclosed in the aforementioned Canadian patent
No. 1,040,908, and moreover, a servo controlled mirror device
or light refracting plate, servo controlled by a galvanometer
:
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.
JPD:jak ~1 9/16/75 19151-5
107~
movement or -the like, can be also utilized. The purpose of
this structure, which will hereinafter more fully appear,
is in the first instance for tracking the light beam 110
along the particular recorded track across the record med-
ium 14.
As the beam 110 tracks along the line or track of
record information, a variable amount of light will be trans-
mitted through the record medium 14, the intensity of laser
74 being such that it will not produce further recording.
The transmitted light is picked up by fiber optic light
collector tube 112 which extends along under the path of
the light beam 110 and conveys the light to detector 114
which includes photoelectric means for providing an output
indicated at 116. The detector also suitably includes a
tracking control circuit performing the function of track-
ing control circuit 108 in Fig. 4 and which may be of the
Canadian
type shown in pending / application Serial No. 230,143
of R. A. Walker, filed June 25" 1974. Alternatively,
tracking circuitry of the type illustrated in my aforemen-
tioned U.S. Patent No. 3,501,586 may be utilized, wherein
motion of the light beam 110 back and forth across the re-
corded track is detected. In any case, a servo output is
produced on lead 118 connected to servo mechanism driving
circuitry 120 and 122 connected respectively to deflection
device 84 and to motor 124 which is adapted to move scanner
12 along record medium 14 as hereinafter more fully des-
cribed. The servo mechanism driving circuitry 120 controls
deflection device 84 for adjusting the light beam 110 in a
direction for following along the previously recorded track
across the record medium 14. An integrating circuit 126
JPD:jak Al 9/16/75 lgl51-5
V~-
also couples servo mechanism circuitry 120 in driving rela-
tion to servo mecllanism driving circuitry 122 so that an
averaged or prolonged error from a predetermined beam posi-
tion causes motor 124 to move the scanner 12 physically
relative to scanner 10. The deflection device 84 causes
the light beam 110 to follow the recorded trace in spite of
small errors in recording medium motion, scanner motion,
vibration, etc.
Referring particularly to Fig. 2, the scanner 12
is mounted upon a bracket 128 slideable upon fixed rails
130 which are parallel to the path of record medium 14.
Motor 124 turns a feed screw 132 which engages a mating
threaded portion in bracket 12~, whereby rotation of the
feed screw physically moves scanner 12 in a direction long-
itudinal of the record medium 14. Rotation of motor 124
also rotates shaft encoder 135 which indicates the location
of scanner 12 relative to scanner 10.
A primary function of the apparatus as thus far
illustrated is the delayed reproduction of information
recorded upon medium 14. By positioning the scanner 12
along the track 130, it is possible to produce a predeter-
mined amount of delay in reproduction, relative to record-
ing, from substantially zero delay to delays involving
several minutes or longer. Thus, if scanner 12 is moved
relative to scanner 10 to nearly an abutting position, it
can be seen that beam 110 can be focused on recording med-
ium 14 at a point nearly coincident with the recording beam
55. A magnetic recording and reproduction system would not
allow such latitude in regard to the timing of the repro-
duction because of the necessity of proximity of the
--10-- '
:
JPD jak Al 9/23/75 19151-S
~7400~i
magnetic writing and reading lleads to the reeording medium
eausing some minimum delay between reeording and reading.
In otner words, the magnetic writing and reading heads
cannot be located at the same plaee, and meehanical inter-
ference results in a necessary delay in reading what has
been recorded. However, in the case of optical writing and
reading, the reading beam can be directed toward substan-
tially the same location on the medium where writing is
taking place, or at any selected point thereafter.
On the other hand, the recording density is so
great in the present system that relative movement of the
scanner 12 away from scanner 10 produces a considerable
delay. The apparatus is suitably employed for producing a
desired delay in reproduction, or for reproducing informa-
tion at a different rate from the rate at which the infor-
mation was recorded. Thus, the scanner 12 can be gradually
moved along tracks 130, under the control of the servo mech-
anism circuitry 122, to produce a desired output rate. The
head 68 is rotated under the control of servo mechanism 134
eoupled in driving relation to motor eoils 66 (in Fig. 1),
and responsive to an output system eloek so that the seanner
12 sueeessively seans aeross reeorded traeks at a rate dic-
tated by sueh external cloek. In the short run, servo
meehanism driving eireuitry 120 eauses defleetion deviee
~4 to keep the beam 110 on traek. A eontinual output from
driving eireuitry 120 through integrator 126 is produeed as
the defleetion deviee 84 diverges eontinually from a "norrnal"
position, eausing servo meehanism 122 to drive the motor 124
JPD:jak Al 9/16/7~ 19]51-5
~)7 ~(~05
for producing gradual movement of the scanner 12 in a
desired ~irection. If the scanning rate of the reading
scanner 12 is lower than the scanning rate of recording
scanner 10, then the scanner 12 will gradually move to the
left in rig. 2, or further away from scanner 10. Generally,
the length of possible movement provided will be sufficient
to accommodate prolonged movement of scanner 12 without
running the same mechanically too great a distance. Alter-
natively, a pair of systems as illustrated may be employed
in the alternative so that a scanner 12 of a second overall
system can take over the reading of recorded information
while the scanner 12 of the first system is moved back.
The converse situation arises when -the informa-
tion is being read out at a faster rate than is being recor-
ded, in which case scanner 12 will move ever closer to
scanner 10. A dual system may then again be employed for
reading with a second reading scanner while a first reading
scanner is moved away from its recording scanner 10.
Alternatively, rather than using a plurality of
complete systems, a single system can be employed which
occasionally skips information or replays information.
Thus, in the case of television recording, error can be -
accumulated for a complete frame. Shaft encoder 135 det-
ects a predetermined physical movement of scanner 12 in one
direction or the other, and roughly determines when one
frame of error has been accumulated. Control unit 292
thereupon controls deflection device 86 to move beam 110
along the tape the distance of one recorded frame. Suitably,
each scanning line across the record medium 14 comprises 25
television horizontal raster linQs ~ so that there are 21
-12-
- , . . . .. ..
-- -- , --
JPD:~ak Al 9/16/7~ 19151-5
1 0'7~)10~ i
scanning lines across i:he record medium per frame in the
~25 line ~ C system. For the PAL system 25 such scanning
lines across the medium are involved. The scanning device
84 is servoed by way of circuitry 120 for predetermined
movement in either a backward or forward direction depend-
ing upon the direction of accumulated error. The actual
scanning movement to skip a frame or for the replayins of
a frame may take place coincident with the end of a frame
as detected by detector 114 and supplied to control unit
292. Tne light beam 110 will then be locked in a different
track at a different position from the "normall' position
for deflection device 84, and consequently, servo circuitry
120 controls servo circuitry 122 via integrator 126 for pro-
viding the reverse movement of the entire scanner 12. i~hile
skipping or replaying of only one frame is discussed, it is
clear the system .nay skip or replay more than one frame or -~
another predetermined body of information as desired.
This system is useful for transsynchronization,
i.e. for coupling one TV signal into a system which is, say,
one-half field later than the other, or with a drifting
relationship therebetween. The nonsynchronized source is
recorded according to its own input data clock which suit-
ably controls the speed of rotation of scanner 10, and
played back in synchronism with the desired output clock
which controls servo circuitry 134, e.g. as hereinafter
described in connection with the Fig. 8 circuit~
For transcoding, i.e. for converting from one
television standard to another, the TV signal with the dif-
fering standard is recorded by means of scanner 10 and
played back in synchronism with the desired standard by
-13-
JPD:jak Al 9/16/75 19151-5
107 ~00~
means of scanner 12. The frequency standard problems can
be handled in the same manner as transsynchronization des-
cribed above. Eor "cosmetic" purposes it may be desirable
to include the circuit of Fig. 11 in output lead 116 so
that lines can be repeated as desired for filling in gaps.
Thus, the PAL system includes a greater number of scanning
lines, and it is desired to add lines in converting from
NTSC to PAL. ~eferring to Fig. 11, delay line 293 suitably
comprises a digital register having a length to accommodate
data for one TV horizontal line. Both delayed and nonde-
layed outputs are supplied to selector and summing circuit
294. In converting from NTSC to PAL, circuit 294 suitably
selects a given line, say line 1 of a raster in nondelayed
form. For output raster line 2, circuit 294 selec~s the
sum of information from the delayed and nondelayed circuit
paths. For output raster line 3 scanner 12 is directed via
control circuit 292 to rescan input raster line 2 by means
of changing the position of deflection device 86. Then a
third input raster line is read through circuit 294 without
delay. Alternatively, horizontal lines may be merely stored
and repeated, or the output presentation may be altered in
analog fashion.
For transcoding from PAL to NTSC, the selecting
circuit 294 may be employed for deleting some horizontal
lines. In order to bridge the gap caused by skipped lines,
circuitry of the type illustrated in Fig. 11 may be employed
for summing lines. For example, a given raster line 1 is
selected by circuit 294 in nondelayed form. Input raster
line 2 is skipped, and for a second output raster line, the
combination of input raster line 3 and input raster line 1
-14-
JPD:jak Al 9/16/75 19151-5
107~0~i
as delayed are added together in circuit 294. Input raster
line 4 I:ilen becomes output raster line 3 and the sequence
is continued. To avoid vertical compression of the image
various portions of each horizontal line may be deleted in
random fashion. For this purpose, a horizontal line is
stored while logical means may be employed for deleting
selected portions tilereof.
It is desirable to change the position of deflec-
tion device 86 of scanner 12 for skipping a line so that
the flow of output information is continuous despite dele-
tion of information. Alternatively, a first in, first out
memory of the type hereinafter more fully described may be
employed for converting a flow of discontinuous data into
a flow of continuous data. It is understood that various
approaches for cosmetic alteration of transcoded data may
be employed and are understood by those s]~illed in the art.
The system according to the present invention is
clearly useful for delaying an ordinary live television
broadcast for substantially any period of time up to several
minutes. This is of value in live program production,
wherein the director could "preview" the broadcast a few
seconds or minutes before transmission. Also, a "stop
action" facility is readily obtainable with the system
according to the present invention. The deflection device
84 is controlled to reread a given frame or given series of
frames wherein the deflection device 84 causes nearly imme
diate movement of light beam 110 along the record medium
14. The deflection device is controlled from control unit
292 via servo mechanism 120 for replaying the desired por-
tions of the tape for a period of time up to several
JPD:jak Al 9/18/75 1~151-5
~0~4()~
minutes, whereby stop action or instant replay is secured.
Wi-th eaci~ replay, the deflection device 84 is directed far-
ther from its "normal" position, whereby servo mechanism
122 i~ cornmanded via integrating circuit 126 to cause over-
all movement of scanner 12 in the direction away from scan-
ner 10. Slower integration may be employed for this replay
type of operation to prevent excessive oscillation of scan-
ner 12 back and forth along the record medium.
The system according to the present invention may
be employed for indexing and editing purposes, as when the ~ -
recorded information is in digital form. The control unit
292, in such case, suitably comprises a mini-computer adap-
ted to count and keep track of the frames on record medium
14. Servo motors 28 and 30 (in Fig. 2) operating under the
control of servo mechanism circuitry 288 are suitably oper-
ated at variable speeds under the supervision of control
unit 292 (in Fig. 1) for the location of certain frames and
the running of the record medium at various speeds in for-
ward and reverse directions, e.g. over the entire span of
tape carried by reels 16 and 26. An editor, viewing a TV
monitor or the like receiving an input from line 116, repro-
duces sections of the record medium at any speed, e.g. on
a slow motion or frame-by-frarne basis to select the exact
frame which may be of interest. Each frame may be marked
or premarked on the record medium with a different numerical
designation, or the frames may be counted and stored in a
relative manner by the cornputer control. I~hen a wnole pro-
gram's woxth of sesments have been found and selected, they
may be then re-indexed and played out in sequence to another
recorder, suitably duplicatiny the apparatus of Figs. 1-3.
-16-
JPD:jak Al 9/18/75 191~1-5
D~
Each system can operate on a start-stop basis, i.e.
wherein ~he record medium is brought up to speed within
one frar~e time (30 milliseconds) and wherein the deflection
device 84 is employed to compensate for film acceleration
so that start and stop is effectively instantaneous. lnat
is, the deflection device 84 is controlled tosether with
motion oE the record medium 14 so that the deflection de-
vice traces along the recorded track until the record med-
ium comes up to speed.
To measure the motion of the record medium, it is
desirable to provide a velocity detector 290 coupled to
servo mechanism circuit 288. A velocity detector may, for
example, be light sensitive and responsive to doppler fre-
quency shift, with monochromatic light being used.
A further system according to the present inven-
tion is illustrated in Fig. 5 and includes a disc-type re-
cording scanner 136 and a disc-type reading scanner 138
disposed on opposite sides of a record medium which may
comprise film or a plurality of plates 190, 192 adapted to
have information recorded thereon in substantially the same
manner as record medium 14 in the ~revious embodiment.
However, in this embodiment the recording tracks across
the medium will be arcuate shaped rather than substantially
straight lines as in the case of the previous embodiment.
Scanner 136 comprises a disc portion 140 carrying a plural-
ity of objective lenses 142 evenly spaced around the peri-
phery thereof, and internal mirrors 144 for directing a
light beam from laser 150 onto the record medium, forming
beam 154 at the record medium. The scanner 136 further com-
prises a shaft 146 carrying disc portion 140 and rotated by
JPD:jak Al 9/18/75 19151-5
107~
motor 148. Shaft 146 is provided with distributor mirrors
145 posi~ioned about the shaft so each such mirror will
pick up the light beam from the laser and direct the same
to one of the lenses 142 by way OL intervening mirror 144.
A modulator 152 is supplied with an input signal. The mir-
rors ].42 then successively record tracks across the record
mediuM as shaft 146 is turned by motor 148.
The information recorded on medium 190,192 is
read out by scanner 138, such scanner including a disc-
shaped portion 156 supported by a shaft 164 and rotatable
by means of motor 166. Disc-shaped portion 156 is provided
with a plurality of lenses 158 near the periphery thereof
adapted for projecting a reading beam onto the record 190,
192, such beam originating in laser 174 and passing through
deflection device 176 to one of the set of distributor
mirrors 162 which rotate with shaft 164. The mirrors 162
sueeessively refleet the laser beam through one of the
lenses 158 via mirrors 160. Defleetion deviee 176 is suit-
ably of the type illustrated in Fig. 4.
The seanner 138 is supported for rotation by
housing 168 eontaining motor 166 as well as laser 174 and
defleetion deviee 176. Housing 168 is movable along rails
172 througn operation of the feed screw 170 rotated by
motor 184 and haviny a threaded connection with the housing
168. A deteetor 188 is attaehed to housing 168 for movement
therewith, and in addition to providing an output of the
reeorded information the deteetor provides an input for
servo meehanism eireuitry 178 having a control relation with
deflection device 176. Moreover, an integrating circuit
180 eouples the servo meehanism eircuitry 178 to servo
-18-
j LlT~ J/ ~ L~
~V'~ 30~' .
mechanism circuitry 182 for rotating motor 184, thus
moving housing 168, as necessary, for keeping scanner
138 "on track". i~otor 184 i5 further provided with a
shaft digital encoder 186 for supplying feedback, and
the system operates in substantially the same manner as
the previous embodiment, including further control circuitry
as may be employed in conjunction therewith as in the case
of the previous embodiment.
The Fig. 5 embodiment may be further provided with
an input laser 150' and an input modulator 152' on the
opposite side of the axis of scanner 136 from elements 150
and 152. Scanner 138 can be similarly supplied with an
additional laser 174' deflected through operation of
deflection device 176'. L~oreover, an additional detector
188' may be provided. By switching both the recordiny and
playback lasers, recording and reading scans be switched
from a first record medium or plate 190 to a second
record medium plate 192 without interruption, thereby
accomplishing continuous recording and playback with a
fixed plate machine. Of course, when reading is accom-
plished at a delayed time after recording, the readout
laser will be switched after the recording laser.
A further embodiment according to the present in-
vention is illustrated in Fig. 6 and includes coaxial
recording and readout scanners 194 and 196, respectively.
Scanner 194 includes an upper disc portion 198 provided
with objective lenses 210 near the periphery thereof and
a pyramidal mirror 208 for reflecting light from laser 204
30 to a respective lens 210 scanning a record medium 19`7.
The light~from laser 204 is modulated by modulator 206
~ - 19 -
: ' .
JPD:jak ~1 9/18/75 19151-5
~7~
and passes through the hollow shaft 200 of scanner 194, the
shaft being rotated by a motor 202. Reading scanner 196
comprises upper disc portion 212 carrying lenses 220 near
the periphery thereof which receive light from lase 222
passing through deflection device 224 (suitably of ~he Fig.
4 type) and re-,~lected by distributor mirror 216 carried by
shaft 214 to one of lenses 220 via a mirror 218. The shaft
214, suppcrting disc portion 212, is rotated by motor 203.
..enses 220 form a reading beam 226 and the light passing
through the record medium 197 is collected by fiber optic
device 228 leading to a detector 230 for providing an out-
put. The detector further operates servo mechanism 232
which in turn controls deflection device 224 as hereinbe-
fore described.
Instead of employing a single record medium 197,
multiple record mediums or plates may alternatively be
employed in the embodiment of Fig. 6, as were disclosed at
190 and 192 in the Fig. 5 embodiment. The Fig. 6 structure
may be modified to provide a further set of recording and
playback lasers in a manner analogous to -the additional
lasers shown in Fig. 5 for accomplishing continuous record-
ing and playback with a fixed plate machine.
Since the scanners of the Fig. 6 embodiment are
coaxial, substantially no relative physical movement is
permitted between the two scanners. However, deflection
device 224 is suitably controlled by control means 233 sucn
that the reading beam reads the recorded track with a pre-
determined delay subsequent to recording thereof, or so
that reading takes place at a different rate from record-
ing. Of course, the delay possible is somewhat more limited
-20-
,
JP~:jak Al 9/1~/75 19'51-5
~07~
in this embodiment, bu- this embodiment is more compact
than the Fig. 5 embodiment.
It will be understood that the operation of tne
deflection means, detector and control means as well as the
various functional attributes of the embodiments of Fig. 5
and Fig. 6 are suitably substantially the same as ~escribed
in connection with the embodiment of Figs. 1 through 3.
~ ecause of mechanical imperfections, it is desir-
able to provide an "overscan" on each side of the record
medium, for example the tape record medium illustrated at
14 in Fig. 1. This means that the data recorded is recor-
ded in parallel lines, raster-fashion across the tape, but
the ends of the lines do not coincide with the edges of the
tape, nor does each line have to be exactly juxtaposed with
respect to the next. In Figs. 7 and 8 there is illustrated
circuitry for receiving a continuous stream of data (in Fig.
7) which is broken up and segmentally time compressed into
scanning lines across the tape with a slignt gap between
each scanning line and the next. Thus, each segment of
inforI~1ation is speeded up with respect to time, or compres-
sed, so that there are gaps in time between the segments.
When the information is retrieved or read out, the infor-
mation is expanded so the gaps are no longer present.
Referring to Fig. 9, the recording of television
information is illustrated wherein a complete horizontal
TV line is illustrated at 264 including digitized informa-
tion indicated at 265. Horizontal blanking pulses are
indicated at 266. An overscan gap is illustrated at 268
and may (in some instances) constitute the vertical blank-
ing period. It will be noted that a given line for a scan
~21-
:
JPD:jak Al 9/18/7~ 191~1-5
107'~00~i,
of information across the tape comprises the plurality of
television raster lines.
Referring to Fig~ 10, there is illustrated a
record medium 14 in the form of a tape which is substan-
tially transparent except for a multiplicity of recorded
lines or tracks 284 as may be recorded thereupon by scanner
10 illustrated in Figs. 1-3. As hereinbefore mentioned,
the recorded information may actually be in the form of
digital spots which are closely spaced in line. Also, the
scanning lines or tracks 284 are very closely spaced, as
hereinbefore mentioned. The lines or scans are scanned
across the tai?e raster fashion by successive lenses 38,
wherein a line is diagonal across the tape inasmuch as the
ta~e is moving as the scanning ta]ces place. The start of
the next scan is then nearly directly across the tape from
the conclusion of the immediately preceding scan. There-
fore, tracking apparatus employed in readout will easily
- locate each next following scan. The overscan gap corres-
ponds to the short time between the conclusion of a given
scan across the tape and the start of the next scan.
Referring to Fig. 7, data input and an input
clock are provided to a first in, first out memory 234
which may comprise a plurality of Fairchild 3341 ~lOS inte-
grated circuits connected in parallel. The memory 234 is
reset from and-gate 238 when the latter receives a horizon-
tal sync pulse, a vertical sync pulse, and a scanner start
indication from control circuitry indicating that the scan-
ning beam is substantially at the beginning of a digital
scanning line as hereinafter more fully described. Likewise
up-down counter 236 is reset. Now during the overscan gap,
:~'
-22-
JPD:jak ~1 3/1~/75 19151-5
~074~0S
or the gap be~ween recording lines across the tape, input
information is fed in~o memory 23a on the data-in line at
a rate de,ermined by the input clock. At the same time,
up-down counter 236, which receives the memory in clock
and ou~ clock, is counted upwardly. However, no informa-
tion is read out of memory 234 at this time until up-down
counter 236 coun~s up to a "full" condition (indicating a
full memory) at which time counter 236 triggers flip~flop
240 to an "on" condition for enabling and-gate 244.
Thereupon, clock signals from clock generator 242 coupled
through gate 244 causing memory 234 to provide a data out-
put signal to the recorder, i.e. to lead 56 in Fig. 1, for
example. It will be understood that the rotation of head
36 is controlled so that a recording beam 55 from one of
the lenses 38 will be just inside the margin of recording
medium 14 at this time. Thus, the scanner start signal
for gate 238 is suitably derived from a detector 286 (see
Fig. 2) responsive to indicia provided on head 36 fcr ener-
gi~ing gate 238 at the start of the overscan, i.e. when the
position of scanning beam 55 is at the position where data
would ordinarily start without time compression. This
position also corresponds to the conclusion of the just
previous scanning line 284. The record motor speed is
locked to the input clock.
During the scanning line, the output of clock
generator 242 via gate 244 is fed to up-down counter 236
for counting down the latter until the empty condition is
registered for thereby indicating a now empty condition for
memory 234. ~t this time, flip-flop 240 is turned off,
whereby gate 244 is no longer enabled and another overscan
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JPD:jak Al 9/19/75 19151-5
iO7~(~0S
gap occurs. The output of clock generator 242 is also
supplied to divide-by-N counter 250 by way of gate 248,
wherein N equals the number of clock bits per scanning
line across the tape. This is also the number of bit
positions in a line in the instance of digital recording.
Therefore, counter 250 will count out during a line and
provide an output to phase lock detector 246 at the end
of a line. The output of counter 250 will also turn off
the counter input via an inhibiting terminal of gate 248.
At the same time, since memory 234 will "run out" at the
end of a line, up-down counter 236 will provide an empty
signal to phase lock loop detector 246 at the end of a
line. If the pulse edges of the two counters providing
inputs to phase lock detector 246 not coincident, the
phase lock loop provides an analog signal for adjusting
clock pulse generator 242 to the proper frequency so the
correct phase is attained at the end of each line whereby
a desired overscan gap and a desired data flow are pro-
duced. It will be noted that counter 250 is reset by the
"fulli' output from up-down counter 236, indicative of t'ne
start of a scanning line.
Referring to ~ig. 8, circuitry is illustrated
for reading out the scanning lines having the overscan
gap therebetween, and providing a continuous output as
required for audio, video and the like purposes. The
data input is supplied from a playback detector, for exam-
ple from detector 114 in Fig. 1 via line 116. The input
data clock 272 is synchronized with data from the record,
i.e. input data clock 272 is also connected to receive
a synchronizing signal from detector 114, for example.
-2~-
J~D:jak Al 9/19/75 19151-5
10740~
The readout clock signal supplied to memory 252 as well as
to up-do~n counter 280 is suitabl-~ derived from a standard,
such as a color lV receiver color reference erystal.
Memory 252 is suitably a first in, first out
memory similar to memory 234 in Fig. 7. In addition to
data from the playback detector being supplied to memory
252, the same is also coupled to a da~a start detector com-
prising diode 254 coupled to the input of an amplifier 262,
wherein the amplifier input is shunted to ground by a par-
allel combination of capacity 256 and resistor 258 provid-
ing an integrating function. A second or differential
input of amplifier 262 is connected to the adjustable tap
of a potentiometer 260, end points of which are connected
to appropriate voltages for adjusting the detec~ion level
of the circuit. Tne eathode of diode 254 is connected to
the amplifier input whereby the positive going signal
exeursion at the end of oversean gap 268 in Fig. 9 produees
an output from amplifier 262 whieh resets flip-Llop 270.
The input and the output of amplifier 262 stay "up" for the
duration of the seanning line, until the next overscan gap
268 is eneountered at which time amplifier 262 will be baek
biased aeeording to the setting of potentiometer 260. The
eharge on eapaeity 256 is dissi?ated in resistor 258 and
the eireuit awaits the positive exeursion at the end of the
gap.
At the start of data, the output of amplifier 262
resets meMory 252 and eounters 278 and 280 as well as flip-
flop 270. Flip-flop 270 enables and-gate 274 whieh there-
upon eouples eloek pulses from eloek generator 272 into the
memory sueh that input data is read into the same. During
-25-
- - - -. - . . . :
- ~ . : - : .: .
JPD:jak Al 9/19/75 19151-5
:10'7~
the scanning line, information is being fed into memory 252
faster than it is beiny read out, and counter 280 which
receives the in clock and out clock from the mernory detects
when the memory is full, thereupon providing an output to
phase lock detector 282. ~lso, during the scanning lines,
divide-by-N counter 278, which receives the signal from
clock generator 272 by way of gate 276, counts the number
of clock bits per scanning line and provides an output to
the phase lock detector 282 at the end of the line, while
also turning off its input via an inhibiting terminal OL
gate 276. If the pulse edges of the outputs of the two
counters feeding phase lock detector 282 are not coincident,
the phase lock loop produces an analog voltage to adjust
the motor speed for playback, via servo 134 in Fig. 1, for ~:
example, so that data will be supplied at just the riyht
rate for supplying a constant output from the circuit on
the data out line. :
When an overscan gap is ùsed, as described above,
the gap period may be employed for placing index marks on ~ ~
the edge of the tape for detection by detector 290. If ,.
such index marks are provided with a light beam, then the
detector 290 suitably comprises a light source, for example
a laser, and photodetector means. As hereinbefore indica-
ted, the index marks provided are useful for editing func-
tions.
The described system of Figs. 7 and 8 for compres-
sing and expanding data is principally useful in that the
position of the record in the direction of the data lines
becomes much less critical. This problem is not confined
to apparatus for simultaneous recording and reading of
-26-
JPD:ja]~ Al 9/19/75 191~
~74~30S
delayed data, but is also of importance, for example, in
regard to apparatus using the same scanner at different
times for recording and reading, and is applicable to this
type of recording in general. Thus, if continuous informa-
tion such as a television raster is divided up into sepa-
rate segments for recording, the system prevents loss of
information and alleviates synchronization problems.
Fig. 12 illustrates an embodiment of the present
invention employing the same scanner 12' for both recording
and reading information relative to record medium 1~' suit-
ably comprising a tape which is unreeled from reel 16' and
received onto pickup reel 26'. The record medium is again
self-developing. In the particular example illustrated,
thermal treatment is contemplated wherein the record medium
passes through an oven 306 after information has been recor-
ded thereon, and therefore the record medium in this parti-
cular instance may be of the dry silver or free-radical
type. Other types of record medium may be substituted
therefor, for example as hereinbefore described.
Scanner 12' and the associated elements are sub-
stantially similar to scanner 12 as hereinbefore described
with reference to the embodiment of Figs. 1 and 2. Briefly,
scanner 12' comprises a cylinder 60' journaled in bearings
62' secured to an outer cylindrical member 64' which also
supports motor coils 66'. A head 6~' supports pyramidal
mirror 70' at tne forward end thereof for directing light
through a plurality of evenly spaced objective lenses 72'
positioned around the forward angular wall of the head.
Lasers 40' and 74' are alternately employed to
direct beams of light through an optical tube 76' disposed
-27-
.
JP~:jak Al 9/19/75 1~151 ~
1~741L~0~;
along the axis of scanner 12' and including lenses 78' and
80' and a pinhole aperture 82' located therebetween. Lens
30' dir^cts the beam from the pinhole aperture to the pyra-
midal mirror 70' for successively directing the light beam
toward the particular objective lens 72' which is Lracing
across the record medium 14'. Laser 40' is utilized for
recording purposes, and the light thereof passes through a
modulator 44' to which the intelligence to be recorded is
applied, and from the modulator, the light beam passes
through half silvered mirror 300 through the aforementioned
optical tube 76'. A reading laser 74' directs a laser beam
of lesser strength toward mirror 298 which reflects the
same to mirror 300 and from there down the axis of the op-
tical tube 76'. The beam of light from laser 74' is capa-
ble of reading information from medium 14', but not rewrit-
ing further information. Deflection device 84' is housed
between the pinhole aperture 82' and lens 80', with such
deflection device suitably being of substantially the same
type as device 84 hereinbefore described in respect to pre-
vious embodiments. This device is moved only during read-
ing operations.
In the case of recording, lens 80' directs light
from the pinhole upon pyramidal shaped mirror 70' and
through lenses 72' for scanning across the recording medium
14' whereby information may be recorded. Device 84 is con-
trolled to remain in a predetermined axial position. For
subsequently reading back the recorded information, laser
40' is switched off while laser 74' is rendered operative.
The recording medium 14' is backed up and then driven past
the scanner in the forward direction ior reading the recorded
-28-
.
JPD:jak Al 9/l9/73 19151-5
~0'74(~0~
information. As the beam tracks along the line or track of
recorded i-lformation, a variable amount of light will be
transmicted through the record medium 14' and is picked up
by fiber optic collector tube 112'. Tube 112' extends
under the path of the light beam and conveys the light to
detector 114' whicll includes photoelectric means for supply-
ing an output at 116'. Detector 114' suitably includes
tracking control circuitry performing the function of track-
ing control circuit 108 in Fig. 4. A servo output is pro-
duced in response to tracking control for application toservo mechanism driving circuitry 120' which in turn con-
trols deflection device 84' for adjusting the position of
the reading light beam in a direction for following along
the previously recorded track across the record medium 14'.
An integrating circuit 126' couples servo mechanism circuit
120 in driving relation to servo mechanism driving circuit
296 so that an averaged or prolonged error from a predeter-
mined beam position adjusts the speed of record medi~m trans-
port whereby deflection device 8~' can function within pro-
per limits. The deflection device 84' causes the readinglight beam to follow the recorded trace in spite of small
errors in recording medium motion, scanner motion, vibra-
tion, etc. - ;
Tape transport motors 28' and 30' are operated at
a predetermined average speed under the direction of con-
trol unit 292' via servo mechanism circuitry 296. Velocity
feedback is provided from detector 290' which is positioned
along the recording medium for suitably ascertaining the
recording medium velocity, for example, in a manner herein-
before described with respect to detector 290. The velocity
-29-
JPD:jak A1 9/19/7, 13151-5
1074~
information is supplied as feedback to servo mechanism cir-
cuit 296 by way of control unit 292' from which the desired
speed is selected. This speed is then momentarily increased
vr decreased in response to the input from circuit 120' via
integrator 126' for aiding in ~racking the desired informa-
tion on the record medium. Alternatively, the scanner 12'
can be made movable in the manner illustrated in Fig. 2,
and responsive to tracking information in the manner des-
cribed in connection with the embodiment of Fig. 2.
10In initially recording information, the scanner
12' is suitably rotated via servo mechanism circuitry 134'
connected to motor coil 66' for substantially synchronizing
the scanner rotation with the input clock. The circuitry
of Fig. 7 is employed for providing an "overscan" gap, with
detector 286' supplying scanner position information for
- gate 238 in Fig. 7 as hereinbefore described with respect
to a previous embodiment. The data out lead in Fig. 7 suit-
ably drives modulator 44' in Fig. 12 via an intermediate
amplifier (not shown). For reading out recorded information,
the detector output on lead 116' is connected to the data in
terminal in Fig. 8. Servo circuit 134' is then controlled
from phase lock detector 282 in Fig~ 8.
In addition to the readout of recorded information
in a straightforward manner, the Fig. 12 system may be em-
ployed in the readout mode for editing and the like as here-
inbefore described with respect to previous embodiments.
The motion of the film via servo circuitry 296 is controlled
to minimize offset of deflector device 84', but the deflec-
tor device is employed to compensate for acceleration con-
ditions of the recording medium.
-30-
JPD:jak Al 9/13/75 19151-5
1~74(~05
Instead of detector 114' and light collector tube
112' in the Fig. 12 embodiment, responsive to lignt through
a transl.nissive recording medium, a de~ector 302 provided
with a light collector tube 304 may be employed, i.e. if
the recording medium is reflective.
While the embodiment of Fig. 12 illustrates a
single scanner of the cylindrical type employed for both
recording and reading of information, it is clear the disc
type scanners of Fig. 5 and Fig. 6 may be similarly adapted,
for example, the scanner 138 in the lower portion of Fig.
5 may be so used, with provision for a more powerful laser
for recording. A transmission detector for readout may
also be employed, for example a detector substantially simi-
lar to detector 230 in the Fig. 6 embodiment provided with
a fiber optic device 228. When individual record plates
are utilized, a separate oven may be employed for developing
such plates.
In the case of either the single scanner or dou-
ble scanner embodiments, the overscan gap circuit of Fig. 7
need not always be employed to provide the gap, and only
the output circuit of Fig. 8 is then employed. For example,
if a television signal is being recorded, the television
camera scan can be controlled so that it sweeps slightly
faster than normal for 25 lines and then stops for a time
gap. Alternatively, a delay means (not shown) can be em-
ployed to store the first half of a given digital line which
is then recorded simultaneously with the second half, i.e.
spatially multiplexed. Of course, if the recorded data is
- not time related or continuous, e.g. in the case of compu-
ter data, the overscan gaps may be inserted without use of
a first in, first out memory.
-31-
.. . .
JPD:jak Al 9/l9/73 191~1~5
0~ .
In the case of the double scanner embodiments,
i.e. whe e separate scanners are employed for writing and
reading out information, the effect of an overscan gap can
be produced in a different manner without the compression
circuit of Fig. 7. Recording is accomplished by means of
the recording scanner, without compression of the informa-
tiOII. Th~ playback scanner for reading such information
then suitahly has a larger diameter than the recording
scanner whereby a longer scan is produced. In other words,
the line of recorded information, across the recording
medium, is scanned more rapidly than it was recorded, effec-
tively leaving gaps between each scanned line so far as the
readout signal is concerned. Then, this information can be
expanded by employing the circuit of Fig. 8.
In regard to recording of digital information on
scanning lines on the recording medium of the present inven-
tion, it is apparent that such lines may be composed either
of opaque spots on an otherwise transparent recording med-
ium, or of transparent spots on an otherwise opaque record-
ing medium.
While I have shown and described several embodi-
ments of my invention, it will be apparent to those skilled
in the art that many changes and modifications may be made
without departing from my invention in its broader aspects.
I therefore intend the appended claims to cover all such
changes and modifications as fall within the true spirit
and scope of my invention.
.
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