JPS61280006A - Rotary head type recording and reproducing device - Google Patents

Abstract

PURPOSE:To reduce waveform distortion in recording which is generated by a rotational transformer by comparing a recording signal passed through the rotational transformer with a reference level by a comparator provided in a rotary cylinder, and shaping the waveform of the signal and recording it. CONSTITUTION:An analog signal is inputted from a terminal 1, a recording processing circuit 2 performs AD conversion, error correction encoding, and modulation encoding, and the resulting signal is passed through the rotational transformer 3, thereby obtaining a waveform whose zero crossing is detected. This waveform is equalized properly and amplified by a recording amplifier 6, and the signal is sent to a rotary head 7 and recorded on a recording medium. Consequently,the distortion generated by the rotational transformer is improved and the signal is recorded on the recording medium, reducing the error rate.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a rotary head type recording and reproducing apparatus for recording and reproducing various digital information.

BACKGROUND OF THE INVENTION Recently, prototypes of rotary head type recording and reproducing apparatuses for digitizing video signals, audio signals, etc. and recording and reproducing them have been actively made. The conventional configuration of the recording system of such an apparatus is as shown in FIG.

An analog signal is input from a terminal 1, and a recording processing circuit 2 performs AD conversion, error correction coding, modulation coding, etc. Next, the recording amplifier 6 equalizes the waveform of the digital signal and amplifies it. The output is supplied through a rotary transformer 3 into a rotary cylinder equipped with a rotary head, flows to the rotary head, and is written on a recording medium. Here, the clock of the digital signal input to the recording amplifier 6 is supplied to the recording processing circuit 2 (through the terminal 8).Next, FIG. 4 shows the waveform of each part. And b is the output of the recording processing circuit 2 latched by the clock.The waveform of this b is the output of the recording amplifier 6.
When it passes through the rotating transformer 3, it becomes as shown in C.

The reason for the change from b to c is the failure of the high-pass characteristics of the rotary transformer 3. That is, since a rotating transformer essentially does not pass direct current, when a waveform with a direct current component passes through it, it is distorted as shown in C. This C waveform flows to the rotary head 7 and is written on the recording medium, but if the magnetic recording medium has essentially nonlinear characteristics, the C waveform
Even if you try to equalize such waveform distortion on the playback side, it will not be possible to equalize it sufficiently. This leads to an increase in error rate.

Problems to be Solved by the Invention It is an object of the present invention to provide a rotary head type recording and reproducing apparatus that reduces the waveform distortion during recording that occurs in the rotary transformer.

Means for Solving the Problems The present invention provides a rotary head type recording characterized in that a recording signal that has passed through a rotary transformer is compared with a reference level by a comparator provided in a rotary cylinder, and the waveform is shaped and recorded. It is a playback device.

In addition, the present invention compares the recording signal that has passed through the rotary transformer with a reference level using a comparator installed in the rotary cylinder to shape the waveform, and operates the waveform-shaped signal in synchronization with the master clock for the recording signal. This is a rotary head type recording/reproducing device characterized by phase synchronizing and recording using a latch circuit.

Operation According to the present invention, the waveform distorted by the rotary transformer is converted back into a digital waveform by the comparator and recorded as a digital waveform. Or, use a comparator to restore the digital waveform,
After that, latch it, take the timing again, and record it.

Embodiment 1 The first embodiment shows a block diagram of a recording system of a rotary head type recording/reproducing apparatus according to a first embodiment of the present invention. The difference between FIG. 1 and the conventional example shown in FIG. 3 is that the recording amplifier 6 is moved toward the rotating head 7 side with the rotating transformer 3 as a boundary, and the space between the recording amplifier 6 and the rotating transformer 3 is The point is that a comparator 4 is inserted in . In this configuration, the output of the recording processing circuit 2 is as shown in FIG. 4 as in the conventional example, and after passing through the rotary transformer 3, as in the conventional example, the output is as shown in FIG. 4C. After that, when it passes through the comparator 4, it becomes a waveform in which the zero crossing of the waveform C is detected, as shown in FIG. 4d. This waveform d is appropriately equalized and amplified by the recording amplifier 6 shown in FIG. 1, and sent to the rotary head 7 to be recorded on a recording medium. As described above, according to this embodiment, by providing the comparator 4, the distortion generated in the rotary transformer 3 can be improved and recorded on the recording medium, and the error rate can be reduced.

FIG. 2 shows a block diagram of a recording system of a rotary head type recording/reproducing apparatus according to a second embodiment of the present invention. The difference between FIG. 2 and FIG. 1 is that the comparator 4 and the recording amplifier 60
The two points are that a latch circuit 6 is provided between them, and that a clock from a terminal 8 is supplied to the latch circuit 5. In such a configuration, the output of the comparator 4 has a waveform as shown in FIG. 4d, similar to the first embodiment. In this waveform, for example, the pulse widths of dl and d2 are different, but this is not the original signal of b. That is, at d, distortion in the amplitude direction has disappeared, but distortion in the phase direction still exists. Therefore, if the latch circuit 5 latches it, the original waveform is restored. Fourth
To explain it with a diagram, if the waveform of d is latched with the clock of e which is delayed by the clock of a, it becomes the waveform of f, which is distorted by simply delaying the waveform of b, which is the output of the recording processing circuit is not included at all. As described above, according to this embodiment, by providing the comparator 4, the latch circuit 6, and a means for transmitting their clocks, it is possible to completely restore the waveform distorted by the rotary transformer 3 to the original waveform, thereby eliminating errors. resulting in a significant reduction in rates.

Here, as a means for supplying the clock into the rotating cylinder, a rotating transformer may be used in the same way as the signal line, or a slip ring may be used. Furthermore, if a clock is reproduced from the recorded signal using a PLL circuit or the like and latched using this, there is no need to supply a clock into the cylinder.

In addition, 1. In the second embodiment, a binary digital signal waveform was handled, but a multivalued waveform of three or more values can be processed in the same way. At this time, the comparator 4 corresponds to the waveform and becomes a multi-value comparator, and the latch circuit 5 becomes a multi-value latch circuit. Further, power to be supplied to these comparators, launch circuits, recording amplifiers, etc. can be supplied into the cylinder by means of slip rings.

As described in detail, according to the present invention, it is possible to restore the waveform distorted by the rotating transformer, and therefore the error rate during reproduction can be significantly reduced, and its practical effects are great. .

[Brief explanation of drawings]

FIG. 1 is a block diagram of a rotary head type recording/reproducing apparatus according to one embodiment of the present invention, FIG. 2 is a block diagram of a rotary head type recording/reproducing apparatus according to another embodiment of the present invention, and FIG. 3 is a block diagram of a rotary head type recording/reproducing apparatus according to another embodiment of the present invention. FIG. 4 is a block diagram of the head type recording/reproducing device, and is a waveform diagram of each part. 4... Comparator, 6... Latch circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person81
Figure and Ha 2 Figure 31!1

Claims (2)

[Claims] (1) A rotary head type recording and reproducing device characterized in that a recording signal that has passed through a rotary transformer is compared with a reference level by a comparator provided in a rotary cylinder, and the waveform is shaped and recorded. (2) A comparator installed in the rotating cylinder compares the recording signal that has passed through the rotating transformer with a reference level and shapes the waveform, and applies this waveform-shaped signal to a latch that operates in synchronization with the recording signal master clock. A rotary head type recording and reproducing device characterized by phase synchronization and recording using a circuit.