JPS58115605A - Erasure system - Google Patents

Abstract

PURPOSE:To obtain a magnetic tape device which records data with high density while shortening IBGs by flowing a current for erasure to a writing heat only at the front end part of a block to be erased and erasing the other part through an erasing head. CONSTITUTION:For a data block B to be erased, the writing head and erasing head of a magnetic head are positioned as shown in a figure. In this case, the erasing head should not be within a range X1, because when an IBG (X1) is short, flowing a current to the erasing head in the range X1 erases even the rear end of a precedent block A. The front end part X2 of the data block B to be erased can not be erased by the erasing head, but erased by flowing th4 current for erasure to the writing head. At this time, the current for erasure which is enough for impulsive erasure is flowed for as long time as the part X2 is passed.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Best Time to See O Technical Field A data plotter erasing method Kj41 in a magnetic tape device manufactured by the present invention.

ψ) Technique 10 Background Magnetic Tape Device This is a device that writes information in the main memory of an information processing device onto magnetic tape, and also reads information on the magnetic tape into the main memory. As is well known, information is generally exchanged between the magnetic tape and the main storage device in units of data blocks.

The magnetic head of a magnetic tape device consists of a read head for control, a write head for writing, and an erase head for erasing.By the way, data is transferred between the Ka data block on the magnetic tape and the data plotter. A non-recording gear, -1 (IBG), is provided.

In order to record data on a magnetic tape at high density, it is necessary to shorten the data block eMv1m and the data block IBG ◇ ω) Problems with the conventional technology When erasing data blocks recorded on a conventional magnetic tape, The method used was to bring the erase head of the magnetic head to the data plotter's 0-first position using the positive position and the eraser, and then apply current to the erase end from there to erase the data.

Therefore, the rear part of the front part is erased, so there is a problem that the IBG cannot be shortened much.

(4) Purpose of the invention The purpose of the present invention is to solve the above-mentioned conventional problems.
The present invention provides a magnetic tape erasing method that enables shortening of nG and therefore high-density recording. (5) Structure of the invention Achieved by an erasing method in which only the leading part of the data block to be erased is erased by passing a current through a write head, and the other parts are erased by an erase head.〇(6) According to the invention EXAMPLES Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is an explanatory diagram of the positions of magnetism and do in the erasing method of the present invention, FIG. 2 is a magnetic head control circuit diagram according to an embodiment of the present invention, and FIG. 8 is a time chart.

In the erasing method of the present invention, as shown in FIG. 1, the write head and erase head of the magnetic head are brought to the positions shown in the figure for the data block (B) to be erased.

The reason why the erase head cannot be brought into the XiO range is that, as mentioned above, when IB (j to l) is short, x
This is because if current is applied to the erase head at point 1, the rear end of the previous block will also be erased.

The leading end x2 of the data block to be erased here cannot be erased by the erase head, but this portion x2 is erased by passing an erasing current through the write head.

The erasing current necessary for erasing is passed through the write head in a pulsed manner only during the time that the portion X2 passes, as shown in the time chart of FIG.

FIG. 2 is a diagram of a magnetic head control circuit according to an embodiment of the present invention, and the circuit portion of the read head not directly related to the present invention is omitted.

In the present invention, an erase signal generation circuit 6 is added compared to the conventional control circuit.

When the erase signal is given, the erase current is generated 1st time.
11 operates to flow an erase current Xs to the erase head 2.A write signal is applied to the 0th order, the write voltage generation circuit 8 operates, and almost simultaneously the KGO signal is applied and the erase signal generation circuit 6 operates. do.

As a result, the light head current control circuit 4
The erasing current Ia is passed through L1, and after a certain period of time Ta, the signal from the erasing signal generation circuit 6 to the write head current control circuit 4 is turned off, and the current in the write head 5 becomes the write current Ib41C.

As described above, in the present invention, the erasing current Ia is caused to flow in the write head 6 only during the period Ta, and in this case, the information current Is of the write head and the write current Ib of the write head
, erase small, (do C4 ceramic dowel electric wire h (relationship is 9゜I
b<Is<Io◇ (7) Effects of the Invention As explained above, the present invention provides 511 blocks to be erased.
Since the erase current is applied to the write head only for the i part and the other parts are erased by the erase head, when erasing a block, the data at the rear end of the previous block is not affected, and the IBG can be erased. A magnetic tape device capable of recording high-density data can be achieved by reducing the length of the tape to 0.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the position of the magnetic head in the erasing method of the present invention, FIG. 2 is a magnetic head control circuit diagram according to an embodiment of the present invention, and FIG. 8 is a time chart. In the figure, l is the erase current generation circuit. 2 is an erase voltage generator, and 8 is a write voltage generation circuit. 4a light head current control circuit, 5 light head, 6
indicates an erase signal generation circuit.

Claims (1)

[Claims] In a data erasing method for a magnetic tape device that records data in units of blocks, only the leading part of the data tape to be erased is erased with a write head, and the other parts are erased with an erase head. Elimination method.