Video tape recorders

Claim 2

A video tape machine including a cylindrical scanner drum (10), means (40) for defining a datum for a tape extending around the drum, and a guide assembly comprising at least one rotatable roller guide (9a) defining the start of a helical path along the datum and at least one rotatable roller guide (12a) defining the termination of the helical path, at least one of the said rollers being tapered in order to resist movement of the tape away from the datum.

Claim 3

A machine according to claim 1 in which the means (40) for defining a datum comprises a fixed helically extending guide member.

Claim 4

A machine according to claim 1 or claim 2, in which the angle of the taper is in the range from 0°10' to 0020'.

Claim 5

A machine according to any of claims 1 to 3 further comprising means for altering (44) the axis of rotation of the respective guide in a plane generally tangential to the drum.

Claim 6

A machine according to claim 3 or claim 4 further comprising means (44, 45) operable independently to alter the tilt of both guides relative to the drum.

Claim 7

A video tape recording or playback machine characterised by the combination of guide means (40) for engaging a single edge of the tape, to provide a datum defining a path for the tape past a scanner (10), and at least one rotatable roller guide (9a) disposed at the commencement of the tape path, the guide being of part-conical form so as to provide resistance to movement of the tape away from the datum.

Claim 8

A video tape recording or playback machine characterised by the combination of guide means (40) for engaging a single edge of the tape, to provide a datum defining a path for the tape past a scanner (10), and at least one rotatable roller guide (9a) disposed at the commencement of the tape path, the guide being of part-conical form so as to provide resistance to movement of the tape away from the datum.

Claim 9

A machine according to claim 6 in which the roller guide (9a) is tiltable to adjust the tape relative to the datum.

Claim 10

A machine according to claim 7, characterised by a second roller guide (9b) generally parallel to the first roller guide (9a)., these two roller guides being disposed for successive engagement by the tape and being tiltable independently to adjust the displacement of the tape from the guide means and the angle of the tape relative to the path defined by the guide means.

Claim 11

A video tape machine including a cylindrical scanner drum (10) and a guide assembly (9,12,40) for guiding tape in a path extending helically around the drum, the guide assembly comprising a pair of entrance roller guides (9a,9b) of which a first (9a) is disposed close to the drum and of which a second (9b) is spaced laterally from the first, the entrance guides being positioned for successive engagement by the tape, and a pair of exit roller guides (12a,12b) of which a first (12a) is disposed close to the drum and of which a second (12b) is spaced laterally from the first, the exit guides being positioned for successive engagement by the tape and the helical path extending for nearly 360° around the drum from the said first entrance guide to the said first exit guide.

Claim 12

A video tape machine including a cylindrical scanner drum (10) and a guide assembly (9,12,40) for guiding tape in a path extending helically around the drum, the guide assembly comprising a pair of entrance roller guides (9a,9b) of which a first (9a) is disposed close to the drum and of which a second (9b) is spaced laterally from the first, the entrance guides being positioned for successive engagement by the tape, and a pair of exit roller guides (12a,12b) of which a first (12a) is disposed close to the drum and of which a second (12b) is spaced laterally from the first, the exit guides being positioned for successive engagement by the tape and the helical path extending for nearly 360° around the drum from the said first entrance guide to the said first exit guide.

Claim 13

A machine according to claim 9 in which at least one of the said guides (9a,9b,12a,12b) is tapered.

Claim 14

A machine according to claim 9 in which at least one of each pair of guides is tapered.

Claim 15

A machine according to claim 9, further comprising means (44,74) for adjusting the tilt relatively to the drum of at least one of the guides.

Claim 16

A machine according to claim 9 further comprising means (43,44) for adjusting the tilt, relative to the drum, of at least one pair of the said guides.

Claim 17

A machine according to claim 9 further comprising means (42-45) for adjusting the tilt relative to the drum of. both pairs of guides.

Claim 18

A machine according to claim 13 in which the means for adjusting comprises a respective carrier (43,44) for each guide of the pair, a support (41) for the carriers and means (47,74) for adjustably pivoting each respective carrier with respect to the support.

Claim 19

A machine according to claim 15 in which at least one of the guides is tapered to resist movement of the tape away from a datum defining said helical path.

Claim 20

A machine according to claim 16 in which both guides of at least the entrance pair of guides (9a,9b) is tapered in a similar sense.

Claim 21

A machine according to claim 17 in which the guides of the exit pair of guides (12a,12b) are similarly tapered.

Claim 22

A machine according to claim 15 in which the adjusting means comprises means (78-80) for biassing the carrier towards a defined position.

Claim 23

A machine according to claim 9 in which the guide rollers of each pair provide in combination approximately 180 0 of turn in the direction of movement of the tape.

Claim 24

A machine according to claim 20 in which at least one of the entrance guides (9a,9b) has a taper in the range from 10' to 20' of arc so as to resist movement of the tape away from a datum defining the helical path for one edge of the tape.

Claim 25

A machine according to claim 20 in which at least one of the exit guides (12a,12b) is tapered likewise.

Claim 26

A machine according to claim 1 or claim 9 or claim 20 further comprising means (101-110) responsive to the height of the tape path adjacent the assembly for controlling the tilt relative to the drum of at least one (9b) of the guides.

Claim 27

A video tape machine including a cylindrical scanner drum (10), means (40) for defining a helical datum for a tape extending around the drum, a guide assembly comprising at least one rotatable roller guide (9a) defining the commencement of a helical path along said datum and at least one rotatable roller guide (12a) defining the termination of the helical path, and means (43) for adjusting a tilt angle of at least one of the said guides so as to adjust the positional relationship of said tape and said helical path.

Claim 28

A video tape machine including a cylindrical scanner drum (10), means (40) for defining a helical datum for a tape extending around the drum, a guide assembly comprising at least one rotatable roller guide (9a) defining the commencement of a helical path along said datum and at least one rotatable roller guide (12a) defining the termination of the helical path, and means (43) for adjusting a tilt angle of at least one of the said guides so as to adjust the positional relationship of said tape and said helical path.

Claim 29

A video tape machine including a cylindrical scanner drum (10) and a guide assembly (9,12,40) for guiding tape in a path extending helically around the drum between a supply reel (3) and a take-up reel (23) positioned relative to the drum so as to require a large change in direction of tape movement between the supply reel and drum and between the take-up reel and drum, the guide assembly comprising a pair of entrance roller guides (9ai,9b) of which a first (9a) is disposed close to the drum and of which a second (9b) is spaced laterally from the first along a line generally radial to the drum, the entrance guides being positioned for successive engagement by the tape and being located relative to the supply reel and the drum to define a large change in direction of tape transport between the supply reel and the drum, and a pair of exit roller guides (12a,12b) of which a first (12a) is disposed close to the drum and of which a second (12b) is spaced laterally from the first along a line generally radial to the drum, the exit guides being positioned for successive engagement by the tape and being . located relative to the take-up reel and the drum to define a large change in direction of tape transport between the take-up reel and the drum, the said helical path extending for nearly 360 around the drum from the said first entrance guide to the said first exit guide.

Claim 30

A video tape machine including a cylindrical scanner drum (10) and a guide assembly (9,12,40) for guiding tape in a path extending helically around the drum between a supply reel (3) and a take-up reel (23) positioned relative to the drum so as to require a large change in direction of tape movement between the supply reel and drum and between the take-up reel and drum, the guide assembly comprising a pair of entrance roller guides (9ai,9b) of which a first (9a) is disposed close to the drum and of which a second (9b) is spaced laterally from the first along a line generally radial to the drum, the entrance guides being positioned for successive engagement by the tape and being located relative to the supply reel and the drum to define a large change in direction of tape transport between the supply reel and the drum, and a pair of exit roller guides (12a,12b) of which a first (12a) is disposed close to the drum and of which a second (12b) is spaced laterally from the first along a line generally radial to the drum, the exit guides being positioned for successive engagement by the tape and being . located relative to the take-up reel and the drum to define a large change in direction of tape transport between the take-up reel and the drum, the said helical path extending for nearly 360 around the drum from the said first entrance guide to the said first exit guide.