|
227679
Phonograph, T. A. Edison, 1880-05-18, 369/214; 116/144; 181/162 -
A cylinder has a helical groove that wiggles up and
down to record sound.
The Poulsen device is a cylinder with a helical wire
that magnetically records sound.
|

|
661619
Method of recording and reproducing sounds or signals,
Valdemar
Poulsen, 1900-11-13, 360/87; 235/449; 379/70; 360/136
-
Although the patent does not use the words, one of the
applications is as a telephone answering machine,
hence "Telegraphone".
Poulsen probably had seen images of the Edison
Cylinder machine if not a real one in action since it
had been around for a decade.
His idea duplicates the Edison Cylinder except instead
of cutting grooves in wax Poulsen is magnetizing a
wire would around a cylinder. This is for all
intents and purposes a wire recorder (Wiki)
but with a much shorter wire wound on a cylinder.
|

|
773985
Apparatus for recording and reproducing speech, Elias
E Ries, 1904-11-01, 360/89; 242/125.1; 242/324.1 -
wire recorder
|

|
788728
Apparatus for electromagnetically receiving,
recording, reproducing, and distributing articulate
speech, &c., Valdemar
Poulsen,1905-05-02, 360/7 - steel
wire (a) loop moved by pulleys.
|

|
789336
Telegraphone, Valdemar
Poulsen, Peder
O Pedersen, Carl
Schou, 1905-05-09, 360/71; 360/72.3; 360/89;
242/324.3 -
Only the last of 6 pages of drawings shown here.
|
|
850036
Telegraphone, George
Morin, 1907-04-09, 360/86 -
removable steel disk (23) used to record voices
|

|
873078
Electromagnet for telegraphone purposes, Peder
Olof Pedersen,Valdemar
Poulsen, American
Telegraphone, 1907-12-10, 360/125.01 -
This is probably the first magnetic recording
head. But it has a lot of room for improvement.
|

|
873083
Telegraphone, Valdemar
Poulsen, Peder
Olof Pedersen, American
Telegraphone, 1907-12-10, 360/66-
A horseshoe magnet is used to both erase and polarize
the media.
|

|
900304
Electromagnet for telegraphones, Peder
Olof Pedersen,Valdemar
Poulsen, American
Telegraphone,1908-10-06, 360/123.01 -
While not much improvement in the recording head, Fig
5 does show the steel wire on a spool, so now looking
like a reel to reel wire recorder.
Now all that's needed to me more modern is a horseshoe
core with a very narrow gap on the recording head.
|
|
1237496
Telegraphone, Charles
K Fankhauser, Arthur
M McCrillis, 1917-08-21, 360/73.14; 242/324.3; 360/110 -
wire recorder, Pointer (83) and dial (84) indicate the
percentage of wire used by indicating the radius of
the spool.
|
|
1142384
Telegraphone, George
S Tiffany, American
Telegraphone Co, 1915-06-08, - rod type
electromagnet as head
|
|
1560721
Automatic reel-stopping device for record-o-phones,
Hugh P O'reilly, Record-O-Phone,
1925-11-10, 242/333; 360/74.2; 242/324.1;
G9B/25.008; G9B/15.034; G9B/15.019 -
Emerson Record-O-Phone Telegraphone (see: Museum
of Magnetic recording\Wire Recording) for photos
|

|
1640881
Radio telegraph system, Wendell
L Carlson, Glenn
W Carpenter, App: 1921-03-26, Pub: 1927-08-30, 360/66; 346/33M -
used to record German military burst transmissions (Wiki)
and play back slower. See See the GRA-71.
Introduced AC bias of the head
replacing prior art DC head bias. But it was
forgotten.
|
|
DE500900
Phonetic carrier, Fritz
Pfleumer, 1930-06-26
|

|
1653467
Record for reproducing sound tones and action, Joseph
A. O'neill, 1927-12-20, 369/16; 360/134; 427/132;
430/140; 427/130; 427/482 - magnetic paper
tape
|
|
2080100
Method and means for storing and selecting records, Tauschek
Gustav, 1937-05-11, 360/86; G9B/5.181; 360/55;
360/78.01; 235/449; 360/62 - not a magnetic
drum data storage device, but rather a storage device
that uses magnets to select the desired bin.
|
|
2144844
Magnetic telegraphone, Clarence
N Hickman, Bell
Labs, 1939-01-24, 360/86; G9B/25.003; G9B/5.293;
29/DIG.28; 369/278; 984/360; 360/135; 984/359 -
Bell Labs was doing a lot of work on underwater sound
with a cover story about analyzing human speech around
this time which required playback of sounds over and
over, see Audio
Analysis Patents.
|
|
2514578
Sound recording and reproduction system, Herman
S Heller, Willard
E Stofer, 1950-07-11, - multiple lanes allow for
more recording time for the same length of magnetic
media.
|
|
2224854
Magnetic sound recording and reproducing, Begun
Semi Joseph, Magnetone,
1940-12-17, 360/71; 242/327.3; 242/324.1 -
continuous loop mag tape recorder
|
|
2230913
Magnetic sound recorder, Schuller
Eduard, Licentia
Patent Verwaltungs GmbH, 1941-02-04, 360/118; G9B/5.04 - ring
shaped head & tape: "carbonyl iron powder with a
base layer of cellulose acetate" |
|
2245286
Electromagnetic sound
recording, Marzocchi
Luigi, Priority: Jun 26,
1936, Pub: Jun 10,
1941, 360/84,
369/97,
360/83,
346/139.00A,
360/122 -
scanned mag tape recording
referenced
by 91 patents |
|
2247847
Recording and reproducing device for magnetic sound
writing, Pfleumer
Fritz, 1941-07-01, 360/110; G9B/5.04; G9B/5.147;
346/33M; 29/DIG.28 - the head
"electromagnetic arrangement is used which functions
entirely without iron" That way there is to
residual magnetism in the head that can act to erase a
recorded tape.
|
|
2229293 See Memorox Paper Magnetic Disc
Recording
|
|
2306162
Sound device, Harrison
S Gipe, App: 1940-08-08, W.W.II, Pub:
1942-12-22, 360/89; 242/324.3; 360/75 -
suitcase size, talks about problems with both tape and
wire media. |
|
D149541
Wire Recorder, Colin
B Dale, Webster-Chicago,
1948-05-11, - Model 80 portable design |
|
2364556
Telegraphone, Richard
M Somers, Thomas
A Edison Inc, 1944-12-05, 360/63; G9B/27.051; G9B/15.121;
G9B/15.031; 360/93 - cassette with built-in
recording head and multi-track tape that auto
sequences and auto-reverses, like for dictation. |
Armour
Research Models 20 & 50
|
|

|
2351003
Recording and reproducing of vibrations,
Camras Marvin, Korzon William, App:
1940-09-11, W.W.II, Pub: 1944-06-13, - wire
recorder.
Fig 7: bronze core wire with magnetic coating.
|

|
2351004
Method and means of magnetic recording, Camras
Marvin, App: 1941-12-22, W.W.II, Pub:
1944-06-13, -
The operating point on the B-H curve is
optimized for low distortion.
|

|
2351005
Magnetic recorder, App: 1942-07-27, W.W.II,
Pub: 1944-06-13, -
Military wire recorder Armour Research
Foundation Model 50A ground. Used with
the Model 20 airborne recorder.
Photos in Ref 6, psge 667
|

|
2351006
Magnetic recording head, Camras Marvin, App:
1942-07-27, W.W.II, Pub: 1944-06-13, -
Wire deck for models 20 and 50.
|

|
2351007
Magnetic recording head, Camras Marvin, App:
1942-08-10, W.W.II, Pub: 1944-06-13, -
Wire head
|

|
2351008
Method of and means for neutralizing inductive
disturbances in magnetic reproducers, Camras
Marvin, App:1942-11-18, W.W.II, Pub:
1944-06-13, -
Stray magnetic fields from the transformer,
choke, motor &Etc are bucked out using an
auxiliary coil near the actual pickup coil.
|

|
2351009
Combination oscillator coil and erasing head
for magnetic recorders, Camras Marvin,
App:1942-11-18, W.W.II, Pub: 1944-06-13, -
By combining the erase and bias it may be that
you cannot over record.
|

|
2351010
Method of and means for controlling high
frequency voltage in magnetic recorder heads,
Camras Marvin, App:1942-12-26, W.W.II, Pub:
1944-06-13, - |
same drawing as
above
|
2351011
Method of and means for energizing magnetic
recorder heads, Camras
Marvin, Armour Research, 1944-06-13, 360/66; 360/118;
29/DIG.28 - includes oscillator (18)
"...Also an object of the invention resides in
the provision of an electrical circuit
arrangement for a magnetic recording device in
which the output of an oscillatory hook-up is
divided into a plurality of parts connected in
series, one of the parts functioning as an
erasing head to recondition the previously
magnetized recording medium, and another part
being directly associated with the recording
head of the device to set up a high frequency
magnetic field in the recording head." |
|
|
2369017
Magnetic recorder and drive therefor, Camras
Marvin, Armour
Research Foundation, App: 1943-02-25, W.W.II,
Pub: 1945-02-06, 242/356.5; 360/89; 476/11 -
Wire recorder with resilient motor mount for smooth
start with no jerks.
|
|
2351005
Magnetic recorder, Camras
Marvin, Armour
Research, App: 1942-07-27, W.W.II, Pub:
1944-06-13, 360/89; 242/324.3 - Wire
(or tape), Introduces the need for a bias oscillator
(Fig 7). |
|
2378388
Recording and reproducing device, Begun
Semi Joseph, Brush
Development Co, App:1942-01-01, W.W.II, Pub:
1945-06-19, 324/112; 324/120; 346/21; 360/5;
361/149; 367/135; 324/180; 346/25; 361/143; 361/151
- continuous wire loop for transient analysis
|
|
2380392
Magnetic recording and reproducing, Begun
Semi Joseph, Magnetone,
App: 1943-07-21, W.W.II, Pub: 1945-07-31, 360/7; G9B/31; 360/31; 369/7 -
time delay loop, for broadcasters "kill button".
|
|
2414976
Flight recording instrument, William
S Redhed, 1947-01-28, 346/7; 346/49; 346/139R;
346/145 - mechanical pen on paper chart, for
experimental aircraft and training
|
|
2416610
Magnetic recorder utilizing an energizing oscillating
circuit, Camras
Marvin, Raymond
E Zenner, Armour
Research, App: 1942-12-26, W.W.II, Pub:
1947-02-25, 360/66; 360/130.2; 360/89 -
wire recorder, mostly about small size for use on
aircraft AIC circuits, "...such an oscillating circuit
is understood by those skilled in the art. " So the
bias oscillator came earlier. |

|
2419195
Apparatus and method for magnetic recording, Begun
Semi Joseph, Brush
Development Co, App: 1944-06-16, W.W.II, Pub:
1947-04-22, 360/29; 29/DIG.28; 346/33M;
G9B/5.031 - for transient analysis
The underwater audio signals from ships and submarines
involve frequencies below hearing. These signals
are also very difficult to record directly onto
magnetic media. By using FM modulation prior to
recording signals down to and including DC can be
recorded. This is needed to do audio
analysis of these signals.
See: Ref 4
& Ref 5.
|
|
2461368
Magnetic transducing
apparatus utilizing a helical sound trace, William
E Bradiey, Philco
Corp, Filed: Dec 19, 1944,
Pub: Feb 8, 1949, 360/29
- wire recorder. They had problems with wire
rotation. |
|
2466514
Magnetic recording and reproducing device with means
to prevent accidental erase of record medium, Harold
A Vagtborg, Armour
Research Foundation, App: 1944-11-23, SECRET, Pub:
1949-04-05, 360/60; G9B/15.008; 242/324.2 -
Spool interlock to prevent overwriting.
|
|
2467507
Wire feed for magnetic recorders, Irving
A Stone, Wirecorder
Corp, 1949-04-19, 360/89; 226/181; 242/324.1 -
uses capstan (Wiki)
instead of small storage spool and fixed large
spool/flywheel. Complex & Expensive.
|
|
2475421
Combined erasing and recording magnetic transducer, Camras
Marvin, Armour
Research, 1949-07-05, 360/121; 360/123.01; 336/184;
336/178; 360/118 - "E" core head with
seperate gaps and windings for Erase and
Record/Play. Both 2 and 3 gap versions (erase,
record, play).
|
|
2481004
Wire recorder, Colin
B Dale, Webster-Chicago,
1949-09-06, 242/324.1 -
wire tension control (to prevent breaking wire or
letting it tangle).
|
|
2493657
Method of winding wire onto a spool, Colin
B Dale, Webster-Chicago,
1949-09-06, 1950-01-03, 242/324.3 -
the spools move up & down to spread the wire
evenly. |
|
2499699
Wire and tape driving means, Russell
J Tinkham, Magnecord,
1950-03-07, 226/183; G9B/15.039; 226/155 -
without using sprocket holes - capstan drive shaft
(13) is hard, pinch rollers (14 & 15) are soft. |
|
2513617
Magnetic recording and reproducing, Begun
Semi Joseph, Brush
Development Co, App: 1946-08-06. W.W.II, Pub:
1950-07-04, 360/110; G9B/5.04 -
"...magnetically record or reproduce signals by means
of a moving magnetic signal-carrier filament, such as
a magnetic wire with substantially uniform response
and level characteristics,..." |
|
2515190
Record protector for magnetic recording and
reproducing devices, Camras Marvin, Armour
Research Foundation, App: 1944-07-17, W.W.II,
Pub: 1950-07-18, 360/60; G9B/15.084; G9B/15.006 -
"Upon the rewind and reproduction operations, the
erasing head is automatically cut out of
service." A write protected spool locks rotation
of shaft.
|
|
2521623
Magnetic recording and reproducing, John
P Arndt, John
E Shomer, Brush
Development Co, App: 1945-02-06, W>W.II, Pub:
1950-09-05, 324/112; 360/5; 324/120; 360/88 -
FM modulated for transient analysis |
|
2532541
Mounting for wire recorder supply spools, Colin
B Dale, Webster-Chicago,
1950-12-05, 242/571.4 -
the spools move up & down to spread the wire
evenly. |
|
2536126
Wire recorder spool, Colin
B Dale, Webster-Chicago,
1951-01-02, 242/125.2 -
with pinch to hold end of wire. |

|
2536260
Device for reproducing magnetic records, Jr
Leslie L Burns, RCA,
1951-01-02, 360/123.02; 324/212; 336/160;
G9B/5.105 - "Accordingly, the principal
object of my present invention is to provide a
magnetic phonograph having a substantially linear
frequency response characteristic." uses a balanced
discriminator circuit (Seeley 2121103)
|
|
2537260
Wire recorder, Colin B Dale, WebsterChicago,
1951-01-09, 242/334; 242/324.1; 242/571.4 -
maybe
Model 80 portable, Classic Play - Stop - Rewind
lever at front of deck. |

|
2540654
Data storage system, Arnold
A Cohen, William
R Keye, Charles
B Tompkins, Engineering
Research Assoc, 1951-02-06, 360/51; 235/449; 235/493;
315/244; 324/212; 360/73.03; 360/100.1; 101/93;
346/33M - Magnetic Drum Memory
Cites IBM punch cards (2150256)
as prior art,
Cited by 200 patents! i.e. pioneer digital
magnetic recording
|
|
2551845
Recording head assembly, Harold
W Lindsay, Ampex,
1951-05-08, 360/90; 360/251.3; 360/118;
G9B/15.076; G9B/5.034 - for 1/4" audio
magnetic tape.
|
|
2596536
Wire recorder, Colin
B Dale, Webster-Chicago,
1952-05-13, 242/324.1; 242/333; 242/356.5;
242/586.4; 242/912; 242/597.7; 242/353 -
Nylon or string leader on end of wire |
|
2609457
Electromagnetic sound recorder and reproducer, Thurm
Leon, 1952-09-02, 360/90; G9B/25.005; G9B/15.047;
360/261; 242/356.7 - massive central
flywheel (larger than the case) with two small spools
in a cassette. Multi track monaural tape
recorder. Looks like BoomBox (Wiki).
|
|
2614845
Wire recorder, Colin
B Dale, Webster-Chicago,1952-10-21,
360/89; G9B/15.048; 369/259;
242/324.1; 360/130.1 - maybe to keep the
wire from spilling |
|
2616982
Magnetic recorder, Gray
Robert, Ellis
Robert, Raytheon,
App:1946-08-24, SECRET,
Pub: 1952-11-04, 360/89; 242/324.3 -
small size, reliable, easy to use, battery power; why,
for spies? or use on military vehicle? Record
time can be preset up to 30 minutes, why? mentions
recording conference speeches using desk microphone.
|
|
2618709
Cylindrical contact magnetic head, Jr
John Presper Eckert, Mock Leon
Robert, Eckert
Mauchly Computer Corp (DMCC), 1952-11-18, 360/121; G9B/5.05; G9B/5.051;
G9B/5.035; G9B/15.082; G9B/15.077; G9B/5.076;
360/15; 360/129; 360/128 - multi track
digital tape head
|
|
2629827
Memory system, Jr
John Presper Eckert, John W
Mauchly, - various magnetic memory devices for
computers, 1953-02-24, 360/54; 340/12.14; 365/157;
365/214; 379/280; 310/327; 333/141; 365/76; 365/211;
365/225.5; 327/406; 327/165; 327/263; 369/60.01 -
ENIAC (Wiki)
|
|
2692379
Blocking oscillator magnetic recording device, Dolan
H Toth, Sec
of Navy, 1954-10-19, 360/67; G9B/5.05; G9B/5.033;
346/33M - for digital data, correct closed
loop head design with small gap, the recording head is
also the transformer of the blocking oscillator (also
see Joule
Thief).
|
|
2694656
Magnetic impulse record member, magnetic material, and
method of making magnetic material, Camras Marvin, Armour
Research Foundation,1954-11-16, - calls
DE500900f - for magnetic material for tape recording.
|
|
2698875
Plural track magnetic recording and/or reproducing
apparatus, James
H Greenwood, Magnecord,
1955-01-04, 360/23; 360/63; 386/E5.008;
G9B/5.16; 235/61PL - 6 tracks - "One application of the
invention is in the field of recording television
(video) signals for subsequent reproduction. Another
application of the invention is in the field of
recording military and communication signal currents
of a frequency both within the standard video band
as well as of frequencies above that band which are
considered as falling within the video frequency
range." |
|
2713618
Pocket recorder, Louis
A McNabb, 1955-07-19, 360/89; 360/71; 242/324.1 -
wire recorder, coaxial spools, dual coil "C" shape
read/write head, Record-Off-Rewind-Off-Listen switch,
|
|
2722676
Magnetic information-storing device, Begun
Semi Joseph, Clevite,
1955-11-01 360/61; 360/72.3; 360/78.15;
235/61PL - |
|
2778636
Endless tape cartridge, George
H Eash, Charles
I. Poulsen, 1957-01-22, 242/326.2; 360/132; 242/345.3;
242/615.4 - Wiki: 8-track
tape - |
|
2787750
Speed control system for electric motor, Lawrence
G F Jones, Sperry
Rand, 1957-04-02, - Drum computer memory,
tubes, Cites
13, calls
24,
|

|
2792217
Tape feed mechanism, James
A Weidenhammer, Walter
S Buslik, IBM,
1957-05-14, 226/50; 226/51; 226/186;
G9B/15.075; 714/E11.055; 178/17B -
The free standing tape
recorders used with computers are optimized for the
highest possible speed of access. They can not
afford the mass of the tape tension swing arms, like
on the Magnacord
1024, and have replaced both of them with a
small elevator shaft like compartments where the
tape hangs. There's a control system that
drives the reels to maintain the loop in the
elevator compartments. The tape should be as
light as possible without breaking.
Professional audio tape recorders might run at 15
inches per second, the digital data tape machines
could run at 75 to 200 ips (IBM: 3420).
Overview (HP: 7970)
Another factor is the data formatting which has a data
track per bit so for recording bytes (8 bits) the
recorder will have 9 tracks including a parity track,
hende "9 Track Tape" (Wiki).
There's a limit to how dense the bits can be recorded
because of skew and imperfect alignment of the head
gaps.
Wiki: Magnetic
Tape Data Storage-Technology, IBM
727, IBM 729,
|
|
2794066
System for recording and reproducing television
signals, John
T Mullin, 3M
Co, 1957-05-28, 360/23; 330/148; 327/297;
330/124R; G9B/15.018 - 15750 Hz timing
trace, audio track & 38 other tracks.
|
|
2796571
Electric motor, William
L Dunn, Magnecord,
1957-06-18, 318/722; 310/112;
310/164 - "... single-phase
alternating-current machine that can be used as
a synchronous motor, a variable speed motor, or
a variable speed motor synchronized by external
Synchronizing pulses." i.e. a stepper motor |
(see 2866009)
|
DE970710
Small magnetic sound device for sound recording and
playback, Willi
Draheim, Dipl-Ing
Ernst Genning, Nicholas
Monske, App: 1951-10-28, Pub: 1958-10-16, -
|
|
2819957
Steel alloys for making magnetic recordings, Appel
Karl, C
Pouplier Jr, 1958-01-14, 420/94; G9B/5.237; 420/95;
420/97; 420/96; 420/98 - patent number seen
on a Protona minifon P55 wire reel - Example 6: "This
alloy is made into a wire having a diameter of 0.05
mms. Coercive force 450 oersted, retentivity 3000
gauss, at field intensity 900 oersted. " |
|
2838360
Simplified crash data recorder, John
V Foster, 1958-06-10, 346/74.2; 346/21; 346/7; 346/49;
346/74.5; 346/72; 360/5; 369/75.11 -
magnetic drum
|
|
2866009
Sound recording and sound reproducing apparatus, Genning
Ernst, Draheim
Willi, Monske
Nikolaus, Protona,
App: 1951-10-27, Pub: 1958-12-23, 360/89; 242/355; 360/71; 242/356
- Minifon
2 & 3: 9V Motor Batteries (100ma @ 9V)
4: 1.5V Filament Battery
5: 30V B+ Battery
6: Battery or External Power Switch
7: Motor Control (Run/Stop) also brakes reel and turns
on/off batteries.
8: Volume Control
9: Microphone (2 types) or Earphone Jack
10: Forward/Reverse
11: Supply Reel
12: Takeup Reel
13: Head
14: Permanent Magnet Erase Head
17: Motor
60: Output (short plug 59) headphone 63
63: Input (long plug 58) crystal diaphragm mike 60 or
phone coil
Motor fly-ball governor and Friction brake used to
control wire speed. Ideal is 10 to 12 ips.
Cites:
597782
Telephonic Installation, G. Ritter, 1898-01-25, -
switchboard plugs & jacks
1237496 Telegraphone, see above.
GB567152
apparatus for magnetically recording, reproducing and
transmitting speech and messages,
Robert Saint George Terry, Sydney James Smith,
Telephone Manufacturing, 1945-01-31,
2369017 Magnetic recorder and drive therefor, See above.
2481004 Wire recorder. See above.
2609457 Electromagnetic sound recorder and reproducer.
See above.
2616982 Magnetic recorder, See above.
|
|
2870270
Magnetic reproducing systems, Nagai
Kenzo, Uemura
Saburo, 1959-01-20, 360/123.01; G9B/5.104; 324/253 -
reintroduce AC head bias
|
|
2956114
Broad band magnetic
tape system and method, Charles
E Anderson, Ray
M Dolby, Charles
P Ginsburg, Jr
Shelby F Henderson, Ampex,
Oct 11, 1960, 360/30, 386/E05.9, 386/335 - helical scan
video |

|
2959459
Flight recorder, James
J Ryan, App: 1953-08-04, Pub: 1960-11-08, 346/7; 346/18; 346/32; 346/136;
73/489; 346/23; 346/49; 73/514.13; 73/514.38;
73/514.33 -
This was an analog mechanical system where the data
was recorded on metal foil written on by a stylus.
General
Mills & the University of Minnesota were
involved with this development. General Mills
was also a key player in high altitude balloons.
See Sonobuoy \ Roswell
Connection
General Mills also was involved with the development
of DSV Alvin (Wiki)
|

|
2973156
Tape recorder, Draheim
Willi, Rhein
Handel ges, App: 1956-12-01, Pub: 1961-02-28, 242/356.4; D14/161; 242/355;
242/356.5 - similar to: Joy Stick or car
manual transmission floor mounted lever
|
|
2992296
Crash data recorder, Albrecht
Fritz, 1961-07-11, 360/5; 346/38; 346/21; 346/33M;
976/DIG.207 - magnetic recording on loop,
|
|
3016244
Miniature magnetic sound recording and reproducing
device, Schuh
Carl Friedrich, Bavaria
Lower, Hermann
Gunter, Protona
Prod, 1962-01-09, 242/333; 200/80R; 242/324.3;
242/597.3; 242/357; 242/331.3; 242/356.3 -
Was this the start of the piano keyboard push buttons
that were used on cassette tape players, i.e. Stop,
Rewind, Play Back, Record? The P55 model.
The model in Dragnet 1954 movie was an earlier M55
version. |
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3029684
Camera-projector apparatus, Lowell A
Wilkins, Florence Kane, Henry S Kane,
1962-04-17, 352/29; 352/138; 360/3; 355/31 -
adds optical sound recording
2910911
Portable sound and motion picture camera, optical
sound track
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3068455
Magnetic drum storage systems, Cebern
B Trimble, NCR Corp, 1962-12-11, - vacuum tubes
To prevent head crashes:
1. the heads are retracted during spin-up and
spin-down.
2. Head gap control to counteract temperature
variations.
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3070668
Hand recording apparatus, Owner
John Lechmere, Archer
John, US
Philips, 1962-12-25, 360/117; 360/62; 360/67 -
Hand held magnetic record/reproduce head with
electronics, i.e. manually scan flat media. Toy?
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3077315
Recording medium transport mechanism, Draheim
Willi, Tcck
Unter, Mohl
Karl, App: 1960-04-23, Pub: 1963-02-12, 242/356.5; G9B/15.002; G9B/15.034;
G9B/15.041; G9B/15.05 -
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3134097
Data storage machine, Louis
D Stevens, William
A Goddard, John
J Lynott, IBM
San Jose, 1964-05-19, 360/78.04; 360/75; 360/246.7;
360/267.2; 360/267.9; G9B/25.003; G9B/5.187 -
digital magnetic drum (really writing on the OD of
many disks).
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3264622
System for compensating for tape skew and gap scatter,
Richard
K Gerlach, NCR,
1966-08-02, -
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3612774
Snap-on erasing member for compact cassette recorder,
Edgard
R Wiklund, 1971-10-12 360/128; 360/118; G9B/5.181;
G9B/5.026 - permanent magnets
used to erase cassette tape (Wiki).
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3678481
Data storage apparatus employing a single magnetic
disk, Warren L Dalziel, Jay B Nilson, Donald L
Wartner, IBM
San Jose, 1972-07-18, 360/78.04; G9B/17.011; G9B/17.01;
G9B/5.294; G9B/5.187; 360/99.05; 360/99.06;
360/130.34; 360/133 - 8" Floppy drive
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