US3707707A — Digital cassette magnetic tape recorder and repro…

Claim 1

Independent Claim 226 words

In a digital cassette recorder for use with a cassette of the type having first and second reels rotatably mounted therein with a length of tape wound on the reels, a framework, said framework including a top plate, first and second reel drive shafts rotatably mounted with respect to said framework and extending through said top plate, said shafts being adapted to engage the first and second reels in the cassette to drive the first and second reels, first and second capstans rotatably mounted in the framework and extending through the top plate and being adapted to be disposed adjacent the tape in the cassette, motive means for driving the first and second shafts, first and second motive means connected to said first and second capstans respectively, electrical phase-lock loop means for sensing the speed of rotation of said first and second capstans and connected to said first and second motive means for maintaining a substantially uniform tension on the tape between the capstans during starting, stopping and running conditions of the tape, a carriage, a magnetic head mounted on said carriage, and pinch rollers mounted on said carriage and means for moving said carriage so that said head is moved into engagement with said tape and said pinch rollers are moved into engagement with said tape to urge the tape into engagement with the capstans.

Claim 2

Dependent Claim 226 words

In a digital cassette recorder for use with a cassette of the type having first and second reels rotatably mounted therein with a length of tape wound on the reels, a framework, said framework including a top plate, first and second reel drive shafts rotatably mounted with respect to said framework and extending through said top plate, said shafts being adapted to engage the first and second reels in the cassette to drive the first and second reels, first and second capstans rotatably mounted in the framework and extending through the top plate and being adapted to be disposed adjacent the tape in the cassette, motive means for driving the first and second shafts, first and second motive means connected to said first and second capstans respectively, electrical phase-lock loop means for sensing the speed of rotation of said first and second capstans and connected to said first and second motive means for maintaining a substantially uniform tension on the tape between the capstans during starting, stopping and running conditions of the tape, a carriage, a magnetic head mounted on said carriage, and pinch rollers mounted on said carriage and means for moving said carriage so that said head is moved into engagement with said tape and said pinch rollers are moved into engagement with said tape to urge the tape into engagement with the capstans.

Claim 3

Dependent Claim 37 words

A recorder as claim 1 wherein both of said capstans are operated at substantially constant speeds and wherein the constant speed of one capstan differs by a predetermined amount from the constant speed of the other capstan.

Claim 4

Dependent Claim 71 words

A recorder as in claim 1 wherein said means for sensing the speed of rotation of the capstans includes optical encoder means and wherein said phase locked loop means includes phase comparator means for receiving information from the optical encoder means, a reference oscillator for supplying a reference frequency to the phase comparator means and means for supplying information from the phase comparator means to the motive means for the capstans.

Claim 5

Dependent Claim 30 words

A recorder as in claim 3 wherein said reference oscillator includes means for supplying two reference frequencies in which one reference frequency differs from the other by a predetermined amount.

Claim 6

Dependent Claim 31 words

A recorder as in claim 1 together with means for increasing the torque on the take-up reel of the cassette until the capstans have been brought up to their constant speeds.

Claim 7

Dependent Claim 65 words

A recorder as in claim 1 together with means for changing the motion of one of the capstans from a static condition before changing the motion of the other capstan and means for changing the motion of the other capstan and means for thereafter maintaining the difference in time between the change of motions between the capstans until both capstans reach the same static condition.

Claim 8

Dependent Claim 23 words

A recorder as in claim 6 wherein said first static condition is a stop condition and the second condition is a running condition.

Claim 9

Dependent Claim 24 words

A recorder as in claim 6 wherein said first static condition is a running condition and said second static condition is a stop condition.

Claim 10

Dependent Claim 60 words

A recorder as in claim 1 wherein said means for moving said carriage includes a door mounted on said framework, sAid door being movable between open and closed positions and means engaged by the door as it is moved between open and closed positions for moving said carriage whereby said head is moved between tape engaging and tape disengaging positions.

Claim 11

Dependent Claim 41 words

A recorder as in claim 9 wherein said last named means includes a lever arm pivotally mounted on said top plate, said lever arm having a portion engaging said carriage and having another portion adapted to be engaged by said door.

Claim 12

Dependent Claim 76 words

A recorder as in claim 1 wherein said cassette is of the type having a pair of holes therein adapted to receive the first and second capstans and wherein said cassette has a pair of additional holes therein together with guide pins carried by the top plate and adapted to extend through the additional holes in the cassette, said guide pins being adapted to position said cassette with respect to said head carried by the carriage.

Claim 13

Dependent Claim 41 words

A recorder as in claim 11 wherein said cassette is of the type having a tape having a clear leader on at least one end of the tape together with means for sensing when the clear leader is approaching the head.

Claim 14

Dependent Claim 43 words

A recorder as in claim 12 wherein said means for sensing when the clear leader is approaching the head includes a light source disposed on one side of the tape and means for sensing light disposed on the other side of the tape.

Claim 15

Dependent Claim 18 words

A recorder as in claim 13 wherein said light source is disposed within one of said guide pins.

Claim 16

Dependent Claim 66 words

A recorder as in claim 1 together with additional spring means for positioning said cassette with respect to the tape, said spring means including a spring member adapted to engage one side of the cassette, and at least one additional spring member carried by the carriage and adapted to engage the cassette as the head is moved into engagement with the tape carried by the cassette.

Claim 17

Dependent Claim 23 words

A recorder as in claim 15 together with means adapted to support said cassette in a predetermined plane with respect to said head.

Claim 18

Dependent Claim 37 words

A recorder as in claim 16 together with spring means carried by the framework and adapted to engage one side of the cassette to urge the cassette against the guide pins in a direction toward the head.

Claim 19

Dependent Claim 92 words

A recorder as in claim 1 wherein said head has read and write heads spaced in relatively close proximity to each other so that a mutual inductance is established between the heads, and electrical means including at least one RC network for sensing the current flowing in the write head and for developing an analog voltage of the mutual inductance and for subtracting it from the voltage developed in the read head to provide an output from the read head which is substantially unaffected by information being supplied to the write head.

Claim 20

Dependent Claim 218 words

In a digital cassette recorder of the type for use with a cassette having supply and take-up reels rotatably mounted therein with a length of tape wound on said supply and take-up reels, a framework, said framework including a top plate, first and second reel drive shafts rotatably mounted with respect to said framework and extending above said top plate, means mounted on said first and second reel drive shafts for mating with said supply and take-up reels in the cassette for driving the supply and take-up reels, motive means for driving said first and second reel drive shafts, at least one capstan rotatably mounted on the framework and extending through the top plate and adapted to be disposed on one side of the tape in the cassette, motive means for driving said capstan, a carriage slidably mounted on said top plate, a head mounted on said carriage, a pinch roller mounted on said carriage, a door mounted on said framework and movable between open and closed positions with respect to said top plate, and means operated by the door for moving said carriage and the head and pinch roller carried thereby into a position in which the head engages the tape and the pinch roller engages the tape and urges the tape into engagement with the capstan.

Claim 21

Dependent Claim 218 words

In a digital cassette recorder of the type for use with a cassette having supply and take-up reels rotatably mounted therein with a length of tape wound on said supply and take-up reels, a framework, said framework including a top plate, first and second reel drive shafts rotatably mounted with respect to said framework and extending above said top plate, means mounted on said first and second reel drive shafts for mating with said supply and take-up reels in the cassette for driving the supply and take-up reels, motive means for driving said first and second reel drive shafts, at least one capstan rotatably mounted on the framework and extending through the top plate and adapted to be disposed on one side of the tape in the cassette, motive means for driving said capstan, a carriage slidably mounted on said top plate, a head mounted on said carriage, a pinch roller mounted on said carriage, a door mounted on said framework and movable between open and closed positions with respect to said top plate, and means operated by the door for moving said carriage and the head and pinch roller carried thereby into a position in which the head engages the tape and the pinch roller engages the tape and urges the tape into engagement with the capstan.

Claim 22

Dependent Claim 60 words

A recorder As in claim 19 together with means carried by the face plate for precisely positioning the cassette with respect to the head, said means including spring means mounted on the top plate and adapted to engage one portion of the cartridge and additional spring means carried by the carriage and adapted to engage other portions of the cassette.

Claim 23

Dependent Claim 48 words

A recorder as in claim 20 wherein said cassette is of the type having a pair of holes therein together with guide pins mounted on the top plate and adapted to extend through the additional holes in the cassette to position the cassette with respect to the head.

Claim 24

Dependent Claim 38 words

A recorder as in claim 22 together with spring means carried by the face plate and adapted to engage the cassette to urge the cassette into engagement with the guide pins and in a direction toward the head.

Claim 25

Dependent Claim 161 words

In a recorder, a supply reel and a take-up reel, a length of magnetic tape wound on the supply and take-up reels, means for driving the supply and take-up reels, a magnetic head adapted to engage the magnetic tape as it is being advanced between the supply and take-up reels, said magnetic head having write and read heads in relatively close proximity to each other so that a mutual inductance is established between the write and read heads, means for supplying a write current to the write head, said read head developing a read current, means including at least one RC network for measuring the write current in the write head and developing a signal which is an analog of the mutual inductance between the write and read heads for subtracting it from the signal developed in the read head to provide an output signal from the read head which is substantially unaffected by the information carried by the write head.

Claim 26

Dependent Claim 161 words

In a recorder, a supply reel and a take-up reel, a length of magnetic tape wound on the supply and take-up reels, means for driving the supply and take-up reels, a magnetic head adapted to engage the magnetic tape as it is being advanced between the supply and take-up reels, said magnetic head having write and read heads in relatively close proximity to each other so that a mutual inductance is established between the write and read heads, means for supplying a write current to the write head, said read head developing a read current, means including at least one RC network for measuring the write current in the write head and developing a signal which is an analog of the mutual inductance between the write and read heads for subtracting it from the signal developed in the read head to provide an output signal from the read head which is substantially unaffected by the information carried by the write head.

Claim 27

Dependent Claim 41 words

A recorder as in claim 23 wherein said means for developing a signal representing an analog of the mutual inductance between the write and read heads includes a pair of RC networks operating on the current passing through the write head.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1975-12-26	1976-06-26	1976-12-26	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1979-12-26	1980-06-26	1980-12-26	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1983-12-26	1984-06-26	1984-12-26	$7700.00	Window Closed / Lapsed

Digital cassette magnetic tape recorder and reproducer

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