Video tape recording/reproducing apparatus

Claim 2

A video tape recording/reproducing apparatus comprising a first main rotary head (M1) and a second main rotary head (M2) whose azimuth angles are different to each other, a first sub-rotary head (S1) fixed adjacent the first main rotary head (M1), and a second sub-rotary head (S2) fixed adjacent the second main rotary head (M2), wherein in the reproduction mode a magnetic tape (6) may be driven at a speed different from the speed in the recording mode, and wherein lower signal level sections of the reproduced signal from the first main rotary head (M1) are substituted by the reproduced signal from the first sub-rotary head (S1) and lower signal level sections of the reproduced signal from the second main rotary head (M2) are substituted by the reproduced signal from the second sub-rotary head (S2) characterised by a first means (53, 58, 55) for comparing the amplitudes of the signals from the first main rotary head (M1) and the first sub-rotary head (S1), second means (73, 78, 75) for comparing the amplitudes of the signals from the second main rotary head (M2) and the second sub-rotary head (S2), a third means (52, 57, 54) connected to said first means (53, 58, 55) for selecting for reproduction the signal with the greater amplitude, and a fourth means (72, 77, 74) connected to said second means (73, 78, 75) for selecting for reproduction the signal with the greater amplitude.

Claim 3

A video tape recording/reproducing apparatus in accordance with claim 1, wherein said first means comprises a first amplitude detector (53) for detecting the amplitude of the reproduced signal from the first main rotary head (M1), a second amplitude detector (58) for detecting the amplitude of the reproduced signal from the first sub-rotary head (S1) and a first comparator (55) for comparing the signal level of an output signal of the first amplitude detector (53) with the signal level of an output signal of the second amplitude detector (58) wherein said second means comprises a third amplitude detector (73) for detecting the amplitude of an output signal of the second main rotary head (M2), a fourth amplitude detector (78) for detecting the amplitude of the output signal of the second sub-rotary head (S2) and a second comparator (75) for comparing the signal level of an output signal of the third amplitude detector (73) with the signal level of an output signal of the fourth amplitude detector 78, wherein said third means comprises a first gate circuit (52) for gating the output signal of the first main rotary head (M1) according to an output signal of the first comparator (55), a second gate circuit (57) for gating the output signal of the first sub-rotary head (S1) according to the output signal of the first comparator (55), and a first adder (54) for adding an output signal of the first gate circuit (52) with an output signal of the second gate circuit (57) wherein said fourth means comprises a third gate circuit (72) for gating the output signal of the second main rotary head (M2) according to an output signal of the second comparator (75), a fourth gate circuit (77) for gating the output signal of the second sub-rotary head (S2) according to the output signal of the second comparator (75), and a second adder (74) for adding an output signal of the third gate circuit (72) with an output signal of the fourth gate circuit (78) and wherein there is further provided a first switch circuit (59) for alternately selecting an outut signal of the first adder (54) and an output signal of the second adder (74) on a field by field basis thereby to obtain a continuous reproduced signal.

Claim 4

A video tape recording/reproducing apparatus according to any one of claims 1 or 2, characterised in that the azimuth angle of said first sub-rotary head (S1) is equal to that of said second main rotary head, (M2), and the azimuth angle of said second sub-rotary head (S2) is equal to that of said first main rotary head (M1).

Claim 5

A video tape recording/reproducing apparatus according to claim 3, characterised in that the main rotary heads and the sub-rotary heads have a common plane of rotation.

Claim 6

A video tape recording/reproducing apparatus according to claim 3, characterised in that the planes of rotation of the main rotary heads and the sub-rotary heads are spaced apart by an even number of track pitches.

Claim 7

A video tape recording/reproducing apparatus according to any of claims 1 or 2, characterised in that the azimuth angle of said first sub-rotary head (S1) is equal to that of said first main rotary head (M1), the azimuth angle of said second sub-rotary head (S2) is equal to that of said second main rotary head (M2), and the plane of rotation of said sub-rotary heads is spaced by an odd number of track pitches from the plane of rotation of said main rotary heads.

Claim 8

A video tape recording/reproducing apparatus according any preceding claim, characterised in that the track width of each of said sub-rotary heads is wider than that of each of said main rotary heads.

Claim 9

A video tape recording/reproducing apparatus according to any preceding claim, characterised in that the time lag of said signal provided by each of said sub-rotary heads with respect to said signal provided by each of said main rotary heads is compensated by a delay line.

Claim 10

A video tape recording/reproducing apparatus according to any preceding claim, characterised in that said signal provided by each of said sub-rotary heads compensates said signal provided by the respective main rotary head in synchronization with reproduced horizontal sync signals.