JP2940691B2 - Rotating head type magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Field of the Invention The present invention relates to mounting a rotary head of a rotary head cylinder of a data recorder for using an R-DAT as a storage device of information equipment.

(B) Conventional technology Conventionally, a rotary head for monitoring is mounted on a rotary cylinder with a step difference with respect to a rotary head for recording / reproducing by R-DAT. Three
6) is known. The technical contents will be described below.

As shown in FIG. 3 (a), the rotary head cylinder (1)
The first and second recording / reproducing rotary heads (2a) and (2b) are arranged at positions 180 ° apart from each other, and the first and second recording / reproducing rotary heads (2a) are delayed from the first recording / reproducing rotary head (2a) by 90 ° with respect to the rotation direction of the cylinder. The second monitor rotating head (3a) is arranged at a 90 ° delay from the second recording / reproducing rotating head (2b) while the second monitor rotating head (3b) is arranged. In this case, the four rotary heads (2a) (2b), (3a) (3b) are set in a positional relationship as shown in FIG. 3 (b). That is,
The height (Χ−Y ′) of the first and second monitor rotating heads (3a) and (3b) relative to the height (Χ−Χ ′) of the first and second recording / reproducing rotating heads (2a) and (2b). ′) With the head (2a) (2
The track (T1 ') (T
The monitor rotating heads (3a) and (3b) trace 2 ') so as to have a step 1.5 times the track pitch. By providing a step 1.5 times the track pitch in this manner, as shown in FIG. 4, each head (2a) (2b) (3
a) The trace position in (3b) can be determined.

Thus, based on the head switching pulse signal shown in FIG. 5 (a), the first recording / reproducing rotary head is rotated by 90 ° from the rising edge of the head switching pulse signal as shown in FIG. 5 (b). (2a), and as shown in FIG. 9 (c), during the next 90 ° rotation period Ta ', the second monitor rotating head (3b) and now the first recording / reproducing rotating head (2a). A track (T1 ') formed adjacent to the latest recorded track can be monitored and reproduced.

On the other hand, when the head switching pulse signal falls, the cylinder
During the 90 ° rotation period Tb, recording is performed by the second recording / reproduction rotary head (2b), and during the next 90 ° rotation period Tb ′, the first monitoring rotation head (3a) is used to perform recording. The track (T2 ') formed adjacent to the latest recording track recorded in (2b) can be monitored and reproduced.

The envelope of the recording signal and the monitor reproduction signal at this time is as shown in FIG.

(C) Problems to be Solved by the Invention However, as in the conventional case, the step between the recording / reproducing rotary head and the monitor rotary head is limited to 1.5 × Tp (Tp: track pitch = 13.6 μm). 1.
It is very difficult to install exactly 5 × Tp, and 1.5 × Tp
When it is smaller, the entire width of the track to be monitored cannot be traced, and the monitor output level is reduced.

(D) Means for Solving the Problems The present invention is for solving the above problems,
A rotating head for first and second recording and reproducing and a rotating head for first and second monitoring are provided, and tracks are sequentially formed in a state of overwriting on the tape by the first and second rotating head for recording and reproducing. A rotary head type magnetic recording / reproducing apparatus for monitoring / reproducing a signal of a recording track by a first / second monitoring rotary head, wherein the first / second rotary head for recording / reproducing the latest recording at each point in time; The first and second monitoring rotary heads monitor and reproduce the track before the track, and the four rotations of the first and second recording / reproducing rotary heads and the first and second monitoring rotary heads. The first and second
The rotary head for recording / reproducing and the rotary heads for the first and second monitors are provided on the rotary cylinder with a step, and the allowable range of the step D is set. Where Tp: track pitch TA: head track width of the first and second rotary heads for recording and reproduction TA ': head track width of the first and second rotary heads for monitoring A playback device is provided.

(E) Function According to the above-mentioned means, by mounting the recording / reproducing rotary head and the monitoring rotary head on the rotary cylinder within an allowable range, the recording head can be monitored (recording / reproducing) and the four rotary heads can be used. During playback (simultaneous playback), the rotating head for monitoring can cover an ideal head trace, that is, the entire width of a track to be monitored (reproduced), so that an ideal signal output can be obtained.

(F) Embodiment Hereinafter, an allowable range of a step between the first and second rotating heads for recording and reproduction and the first and second monitoring rotating heads, which is a feature of the present invention, will be described.

First, as shown in FIG. 1, while recording with the first or second rotary head for recording / reproduction (2a) (2b), the first or second rotary head for monitoring (3a) (3b) covers the entire width and runs short. The necessary condition for detecting the signal is P ≧ 0, and under this condition, the step D between the recording / reproducing rotary head and the monitor rotary head is D ≧ 1.5 × TP (Tp: track pitch). .

The first and second rotary heads for recording and reproduction (2a) (2b)
At the time of simultaneous reproduction in which reproduction is performed by a total of four rotary heads, ie, the first and second monitoring rotary heads (3a) and (3b), the first or second recording / reproducing rotary head (2a) as shown in FIG.
When the tracking (ATF) is performed in (2b), a state is established in which the center of the track (A) is traced.

That is, the recording / reproducing rotary heads (2a) and (2b) protrude from the track (A) by the same size S on both left and right sides. Assuming that the head track width of the recording / reproducing rotary head (2a) is TA and the head track width of the monitoring rotary head (3a) is TA ′, the following two equations hold.

TA = Tp + S × 2 TA ′ = Tp + S + P + Q Then, the necessary condition for the monitoring rotary head (3a) to cover the entire width of the track (A) is Q ≧ 0, and the following equation is derived from the above two equations.

Then, since the head step D is D ≦ 1.5 × Tp + P, From the above, the allowable range of the step is: Becomes

In general, the head track width (TA) (TA ') of the recording / reproducing rotary head for R-DAT and the rotary head for monitoring are both manufactured at around 20 [mu] m, and TA = TA' = 20 [mu] m. Since the track pitch of the DAT is 13.6 μm, substituting Tp = 13.6 μm into the equation gives 20.4 μm ≦ D ≦ 23.6 μm.

(G) Effects of the Invention According to the present invention, when a monitor rotary head is mounted on a rotary cylinder with a step formed on a recording / reproducing rotary head, an allowable value of the level difference is set, and mounting is performed within the allowable range. For example, an ideal state for performing monitor reproduction and simultaneous reproduction, that is, a state in which a reproduction signal output can be obtained most, can be ensured. Therefore, the present invention is extremely useful for a data recorder using an R-DAT.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are schematic diagrams for explaining an allowable range of a step between a recording / reproducing rotary head and a monitoring rotary head according to the present invention. FIG. FIG. 2 is a diagram showing the positional relationship between the track and the rotary head at the time of simultaneous reproduction. Third
FIG. 1A is a schematic diagram showing the positional relationship between a recording / reproducing rotary head and a monitor rotary head attached to a rotary cylinder;
FIG. 3 (b) is a schematic diagram showing the mounting position of the rotary head when the step between the recording / reproducing rotary head and the monitor rotary head is 1.5 times the track pitch, and FIG. 4 is a diagram in which the level difference is 1.5 times the track pitch. FIG. 5 (a), (b), (c), and (d) are diagrams showing a positional relationship between a track and a rotary head at a certain time, and FIGS. 5 (a), (b), (c) and (d) are diagrams showing a timing chart and a signal envelope during monitor reproduction. (1) ... rotating cylinder, (2a) (2b) ... first and second
Recording / reproducing rotary head, (3a) (3b)... First and second monitoring rotary heads.

Claims (1)

(57) [Claims] A first rotating head for recording and reproducing data; a first rotating head for recording and reproducing data;
A rotating head for second monitor, tracks are sequentially formed in a state of overwriting on the tape by the first and second rotating heads for recording and reproducing, and signals of recording tracks are formed by the first and second rotating heads for monitoring; A magnetic recording / reproducing apparatus of the rotary head type, which monitors and reproduces a track before and after the latest recording track at each point in time by the first and second rotary heads for recording and reproduction, as the first and second rotary heads for monitoring. Monitor playback, and the first and second
The first and second recording / reproducing rotary heads and the first and second monitoring rotary heads are rotated so that the four rotary heads, the recording / reproducing rotary head and the first and second monitoring rotary heads, reproduce data. The cylinder is provided with a step, and the allowable range of the step D is Where Tp: track pitch TA: head track width of the first and second rotary heads for recording and reproduction TA ': track width of the first and second rotary heads for monitoring apparatus.