JPH0229901A - How to erase recorded signals from recording media - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for erasing recorded signals from a recording medium in a rotating head helical scan type magnetic recording/reproducing device, and particularly relates to a method for erasing recorded signals of rotation erased signals remaining on the recording medium. This is to reduce the impact on

Conventional technology In a conventional rotating head helical scan type magnetic recording/reproducing device, when erasing is performed using a rotating erasing head, the frequency of the erasing signal is set to be as high as possible within the recording signal frequency band, and the gap length of the erasing head is set to be large. The erase effect is obtained by this, and the residual amount of the erase signal is attenuated to a non-problematic level by self-demagnetization.

Problems to be Solved by the Invention However, with the above configuration, a large drive current is required at a high frequency in order to increase the gap length of the rotary erasing head, resulting in a problem of the erasing signal being mixed into the recording/reproducing signal.

In view of the above, the present invention provides a magnetic recording/reproducing device that reduces the mixing of the erasing signal into the recording/reproducing signal when the erasing signal of the rotary erasing head is set to a frequency lower than the upper limit frequency of the recording signal band. It is something.

Means for Solving the Problems The present invention sets the erase signal frequency of the rotary erase head to a frequency lower than the upper limit frequency of the recording signal frequency band, and also adjusts the azimuth angle of the gap of the rotary erase head with respect to the residual erase signal on the tape. The recorded signal is erased by setting an erase signal frequency that maximizes the azimuth loss due to the difference between the azimuth angle of the gap of the recording/reproducing head and the azimuth angle of the gap of the recording/reproducing head.

Effect of the Invention With the above-described configuration, the present invention sets the erasing frequency at which the azimuth loss due to the difference between the azimuth angle of the gap of the rotating erasing head and the azimuth angle of the gap of the recording/reproducing head is maximized with respect to the residual erasing signal on the tape. By erasing the recorded signal, there is no need to widen the gap length of the rotating erase head until it completely self-demagnetizes, so the erase current level can be lowered and the erase signal is prevented from being mixed into the recording/reproduction signal. Can be reduced.

Example Embodiments of the present invention will be described using FIG. 1 and FIG. 2.

As shown in Figure 1, the width of the recording/reproducing track is W1, the azimuth of the gap of the recording/reproducing head is B1, the azimuth of the rotating erase head is λ, and the wavelength of the rotating erase signal on the tape is λ.
, assuming that the difference between the azimuth of the gap between the rotating erase head and the azimuth B of the gap between the recording and reproducing head is 0, the azimuth loss La at the recording and reproducing head for the erase signal frequency of the rotary erase head is as follows. The relationship between the wavelength λ on the tape and the azimuth loss is shown in FIG. As shown in the figure, the recording signal band is, for example, the area surrounded by a wavy line.
The erasing signal wavelength λ at which the azimuth loss at the recording/reproducing head is maximum for the erasing signal at a frequency lower than the upper limit frequency of the recording signal band is Wtan(11/λ=1.2,
3,4. -...9, and by using an erasing signal frequency that corresponds to these wavelengths λ, it is possible to reduce the influence of the erasing signal remaining on the tape on the recording/reproduction signal.

As described above, according to this embodiment, the azimuth loss due to the difference between the azimuth angle of the gap of the rotary erasing head and the azimuth angle of the gap of the recording/reproducing head is maximized for the residual erase signal on the recording medium. By using an erase signal with a certain frequency, it is no longer necessary to make the gap length of the rotating erase head large enough to completely self-demagnetize, and the level of the erase current can be lowered, thereby preventing the erase signal from being mixed into the recording/reproducing signal. is reduced.

As described in detail, according to the present invention, it is possible to reduce the deterioration of the recorded/reproduced signal due to the mixing of the rotation erase signal during recording, and the practical effects thereof are significant.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the azimuth of a rotary erasing head and the azimuth of a recording/reproducing head in an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between azimuth loss and erasing signal wavelength. A... Azimuth of the gap of the rotating erase head,
B: Azimuth of the recording/playback head gap.

Claims (1)

[Claims] When erasing a signal recorded on a recording medium with a rotating erasing head of a rotating head helical scan type magnetic recording/reproducing device, the erasing signal frequency of the rotating erasing head is set to a frequency lower than the upper limit frequency of the recording signal frequency band. At the same time, the erasing signal frequency is set so that the azimuth loss due to the difference between the azimuth angle of the gap of the rotating erasing head and the azimuth angle of the gap of the recording/reproducing head is maximized with respect to the residual erasing signal on the recording medium. A method for erasing a recorded signal on a recording medium, the method comprising erasing a recorded signal on a recording medium.