JPH0253207A - Double azimuth head for magnetic recording and reproducing device - 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] [Industrial Application Field] The present invention relates to a head used in a magnetic recording/reproducing device (VTR1 CR), and more specifically, increases the reproduction voltage in the head to improve the reproduction of video by reproduction signals. This invention relates to a double azimuth head that can improve the S/N ratio.

[Conventional example] Conventionally, the head of this magnetic recording/reproducing device has, for example, a fifth
It has the structure shown in the figure.

In the figure, a head 1 has two magnetic bodies 2, 2 bonded to a helad base 3, and a coil 4 wound around these magnetic bodies 2, 2. Further, as shown in FIG. 6, this head 1 is attached to the lower part of an upper rotary cylinder 6 provided above a lower fixed cylinder 5. Further, in the case of a two-head system, the head 1 is attached at 180 degrees. Moreover, the tip of the head 1, that is, the magnetic tape 7
The width T of the contacting portion is processed to match the width of the track, and the structure is such that a signal is neither recorded on an adjacent track nor picked up from the adjacent track.

Furthermore, in order to prevent that crosstalk,
The azimuth angles of the two heads are different.

Recently, a system has been proposed in which a subhead is added in addition to the two heads 1.1 mentioned above, and the recording track of the magnetic tape 7 is traced faithfully.

[Problems to be Solved by the Invention] By the way, in the head of the above-mentioned recording/reproducing device, not only in normal play but also in special play, the recording signal for one file is read by one head and made into a playback signal. . At this time, the S/N ratio of the image based on the reproduction signal depends on the reproduction voltage obtained by the head, and increases as the voltage increases.

However, the only way to increase the reproduction voltage is to change the width T of the tip of the head 1 or the length of the gap, or to increase the relative speed between the head 1 and the magnetic tape 7.

In other words, the head 1 requires processing on the micron order.
Changing the structure of the motor poses a cost problem, and changing the relative speed requires changing the complex servo mechanism and control, which poses many difficulties.

With this invention, the same track can be approximately doubled by tracing the same track with two heads and adding the reproduction voltage obtained by the two heads.Moreover, the head section is actually the same as the main head and the auxiliary head. It was created in consideration of the above points, focusing on the fact that it has a mechanism that can trace tracks, and its purpose is to increase the reproduction voltage by the head and improve the S/N ratio of reproduced images, etc. Our goal is to provide a double azimuth head that can be used.

[Means for Solving the Problems] In order to achieve the above object, the double azimuth head of the present invention records signals such as images on a magnetic tape, reads the recorded signals, and records and reproduces images, etc. In a magnetic recording/reproducing apparatus that performs
a delay means for delaying a signal read by one of the two heads for a predetermined time; the delay means is provided between the two heads, and they are connected in series; The delay time is set so that the signal read by the previous head and the signal actually read by the subsequent head are aligned in phase.

[Function] With the above configuration, during reproduction by the magnetic recording/reproducing apparatus, the phases of the signals read by the two heads are matched by the delay means. Then, the outputs (reproduction signals) of the double azimuth heads are superimposed, and the output voltage is approximately twice that of a conventional single head. In this way, doubling the voltage level of the reproduced signal can increase the S/N ratio accordingly.

[Example] Hereinafter, in 6 figures for explaining an example of the present invention based on the drawings, the same parts as in Figures 5 and 6 are denoted by the same reference numerals, and redundant explanation will be omitted.

In FIG. 1, the double azimuth head consists of two heads 8 and 9, which are glued to the head base 3 in close proximity to the magnetic tape 7 in the running direction. As shown in FIG. 2, the width T of the tips 2a of the heads 8 and 9 is set to the track width of the magnetic tape 7. Further, the azimuth angles of the heads 8 and 9 are set to the same predetermined value θ. As illustrated in FIG. 3, the heads 8 and 9 are connected in series through a delay element 10, and the signal read by the head 8 is delayed for a predetermined time and then read by the head 9. added to the received signal. Here, the delay time of the delay element 10 is set so that the reproduction signals from the heads 8 and 9 are in phase.

That is, the signal delayed by the delay element 10 is the same as the signal actually read by the head 9. In this way, the reproduction signal (reproduction voltage) read from the double azimuth head is input to the reproduction circuit via the rotary transformer 11.

The double azimuth head A having the above structure is attached to the lower part of the upper rotary cylinder 6 as in the conventional case, as shown in FIG. In addition, in the case of a two-head system, double azimuth head B, which has the same head configuration as double azimuth head A, is installed 180 degrees apart, but the azimuth angle of the heads that make up double azimuth head B is a value different from the above value θ. Set. Further, the other mechanisms are the same as the conventional ones, and the magnetic tape 7 runs diagonally with respect to the upper rotating cylinder 6.

Here, it is assumed that the magnetic recording/reproducing apparatus is in a reproducing operation, the upper rotary cylinder 6 is driven at a predetermined number of rotations, and the magnetic tape is running at a predetermined speed. It is assumed that the double azimuth heads A and B trace the recording track of the magnetic tape 7. First, to explain the double azimuth head A, a signal read by the first head 8 is delayed by a delay element 10 and added to a signal actually read by the next head 8.

Therefore, since the voltage level (reproduction voltage) of the signal obtained by the double azimuth head A is due to the two heads 8 and 9, it is about twice as loud as usual and is input to the reproduction circuit via the rotary transformer 11. and reprocessed.

In this way, the output voltage of a double azimuth head can be approximately doubled by simply making improvements such as providing two heads and connecting a delay element without using an amplifier or the like. If the influence of the element 10 is ignored, it is possible to improve the S/N ratio of the video obtained by the above reproduction process by about 6 dB.

In the case of a two-head system, the other double azimuth head B operates in the same manner as the double azimuth head A described above.

In the above embodiment, the delay element 1o is provided on the primary side of the rotary transformer 11, but two rotary transformers are provided for the two heads 8 and 9, and the delay element 1o is provided on the secondary side of the rotary transformer. A delay element may also be provided.

[Effects of the Invention] As explained above, according to the double azimuth head of the present invention, two heads having the same azimuth angle are arranged close to each other, and the head base is arranged so as to trace the same track on the magnetic tape. We installed a delay element that delayed the signal read by the head before these two heads for a predetermined period of time and added that signal to the signal that was currently being read by the subsequent head. The phase of the signal read by the first head and the signal actually read by the second head is matched, making the output (reproducing voltage) of the double azimuth head about twice that of the conventional one, and increasing the S/N ratio. This improves the S/N ratio of the video when playing the video. Moreover, according to this invention, it is only necessary to glue two identical heads to the head base and add a delay element, and the rest can be left as is, so it can be completed with simple modification and has the effect of being inexpensive. .

[Brief explanation of the drawing]

FIG. 1 is a schematic front view of a double azimuth head showing an embodiment of the present invention, FIG. 2 is a schematic side view of the double azimuth head, and FIG. 3 is a schematic output circuit block of the double azimuth head. Figure 4 shows the above double horse mackerel,
FIG. 5 is a schematic perspective view of a conventional head mechanism; FIG. 6 is a schematic perspective view of a conventional head mechanism. In the figure, 2 is a magnetic material, 3 is a helad base, 4 is a coil, and 7
1 is a magnetic tape, 8 and 9 are heads, and 1o is a delay element. Patent applicant: Fujitsu General Co., Ltd. Agent: Patent attorney: Takuya Ohara

Claims (1)

[Claims] (1) In a magnetic recording/reproducing device that records signals such as images on a magnetic tape and reads the recorded signals to record/reproduce images, etc., two heads with the same azimuth angle are used to track the magnetic tape. a double azimuth head adhered to the base head in close proximity to the base head; and a delay means for delaying a signal read by one of the two heads for a predetermined time, the delay means being connected between the two heads. and connecting them in series, and setting the delay time so that the phase of the signal read by the first of the two heads and the signal actually read by the latter head is aligned. A double azimuth head featuring