JPS6015867A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent an information reproducing error generated due to disturbance of a reproducing information waveform inputted to a sampling circuit by providing the 2nd sampling signal generating means generating a signal having the same period and different phase from a sampling signal and a sampling signal changeover means. CONSTITUTION:When reproducing information 6 extracted from an integration circuit 3 of a pluse shaper section 6 is transferred to an upper priority device, it is discriminated as the presence of error and then the upper priority device issues a re-reading command and an offset command. An offset plus signal and an offset minus signal are inputted to an AND circuit 9 at the same time by the offset command, the AND circuit 9 conducts AND computation and outputs the result to a sampling signal forming circuit 10, which forms the 2nd sampling signal 7 and the signal is outputted to a sampling circuit 8. In case of reading, the swithcing circuit in the sampling circuit 8 is changed over into the combination of the 2nd sampling signal 7 from the 1st sampling signal 4 with the input of the 2nd sampling signal 7 in the collection of the reproducing information at the sampling circuit 8 and the normal reproducing information 8 collected by the sampling circuit 8 is outputted to the next circuit with the 2nd sampling signal 7.

Description

Detailed Description of the Invention <a> Technical Field of the Invention The present invention relates to a magnetic recording and reproducing apparatus that reproduces information by sampling a signal read from a magnetic recording medium using a sampling signal having a predetermined cycle.

(b) Background of the Technology High reliability is required for reproduced information obtained by reading and reproducing information recorded on a magnetic recording medium.

In order to ensure highly reliable reproduction information, various hardware and software techniques have already been applied to each method. However, as the use of magnetic recording and reproducing devices has become more sophisticated, magnetic recording and reproducing devices with various information reproducing means have become more and more reliable. Realization is requested.

(C) Prior Art and Problems An example of a conventional magnetic recording/reproducing device will be described with reference to the drawings.

FIG. 1 shows an example of a conventional magnetic recording/reproducing apparatus, and FIG. 2 shows the state of signal waveforms at each point in time in FIGS. 1 and 3 (described later).

In the figure, 1 is a magnetic helenoid 1-82 is an amplifier section, 3 is an integration circuit section, 4 is a differentiation circuit, 5 is a pulse shaper circuit, and 6
is the pulse shaper EF, Ii, and ma is the sampling circuit (
a) is shown, and ■ to ■ indicate the status of the signal waveform at each time point, respectively.

Reproduction information in a conventional magnetic recording and reproducing device is obtained by reading information on a magnetic recording medium (not shown) with a magnetic head 1,
The read information signal is input to the amplifier section 2, subjected to various processing, and output to the pulse shaper section 6 where the analog waveform is converted into a digital waveform.

The pulse shaper section 6 has two basic circuits, 1
This is a circuit that differentiates the analog waveform ■ input from the Tsuba amplifier section 2 using a differentiating circuit 4, converts the peak signal of the analog waveform ■ into a zero-cross signal, and shapes it into a digital waveform ■. This is a circuit that creates a window for extracting the peak signal of the analog waveform (2) by integrating the analog waveform (2) inputted from the analog waveform (2) in the integrating circuit section (3) (forming it into a digital waveform (2)).

The sampling circuit (a) 7 receives the digital waveform ■ and the digital waveform ■ from the pulse shaper section 6, and receives the sampling signal ■ (hereinafter referred to as the first signal) which is input at a predetermined phase of a predetermined period created inside the magnetic recording/reproducing device. The normal playback information (referred to as a sampling signal) subjected to scene pulling is output to the next circuit (not shown).

Here, if the analog waveform ■ is reproduced in a disordered manner as shown by the broken line, the digital waveform ■ will also become as shown by the broken line, which will be a mismatch condition with the first sampling signal ■ input at a predetermined phase of a predetermined period. This part of the reproduction information is not reproduced, and the reproduction information (2) including the information 'r[4irj:/J error] is output to the next circuit. As a countermeasure to this problem, commands such as offset commands are issued from the control device (not shown) in order to eliminate information reproduction errors. There are some drawbacks.

(d) Purpose of the Invention The present invention has an object to provide a novel magnetic recording/reproducing device that eliminates the drawbacks mentioned above. The object of the present invention is to realize a magnetic recording/reproducing device which can relieve the information reproduction errors that occur and prevent the occurrence of information NY raw errors.

(e) Structure of the Invention The present invention provides a magnetic recording and reproducing device that reproduces information by sampling a signal read out from a magnetic recording medium using a sampling signal having a predetermined period, the device having a sampling signal having a predetermined period. a second sampling signal generation means for generating signals with different phases; and a sampling signal for switching the sampling signal so that when the signal cannot be sampled during information reproduction using the sampling signal, information reproduction is performed using the second sampling signal. This is achieved by a magnetic recording/reproducing device which is equipped with a switching means and is characterized in that it relieves information reproducing errors caused by a disturbed reproduced information waveform input to a sampling circuit of the magnetic recording/reproducing device and prevents information reproducing errors from occurring. I can do it.

(f) Examples of the invention The present invention will be explained below with reference to the drawings.

FIG. 3 shows an embodiment of a magnetic recording/reproducing apparatus according to the present invention.

In the figure, 8 indicates a sampling circuit 1), 9 indicates an AND circuit, and 10 indicates a sampling signal generation circuit, respectively.
Other symbols are No. 11'21. It shows the same content as Fig. 2.

The embodiment shown in FIG. 3 includes a magnetic head 1 that reads information recorded on a magnetic recording medium (not shown), amplifies analog waveform reproduction information read by the magnetic head 1, and removes unnecessary high-frequency noise. An amplifier section 2 outputs an analog waveform ■ that has been subjected to various processing such as attenuating the waveform and limiting the waveform amplitude to keep it constant, and an analog waveform ■ is generated by integrating the analog waveform ■ input from the amplifier section 2. an integrating circuit section 3 that creates a wind pulse (digital waveform ■) to extract the peak signal of , a differentiation circuit 4 that differentiates the analog waveform ■ inputted from the amplifier section 2 and converts the peak signal of the analog waveform ■ into a zero-cross signal; A pulse shaper circuit 5 that shapes the analog waveform (■) differentiated by the differentiator circuit 4 into a digital waveform (■), and an integrating circuit section 3. Differential circuit 4. A pulse shaper section 6 comprising a pulse shaper circuit 5 switches and combines the digital waveform (■) manually input from the pulse shaper section 6 and the digital waveform (■) with the first sampling signal (■) or the second sampling signal (■) to generate normal reproduction information (■). Sampling circuit (b) that samples and outputs to the next circuit (not shown) 8, offset, 7 plus and minus signals (signals without shifting the magnetic head on the magnetic medium in the vertical direction) and calculates the AND result. The AND circuit 9 outputs the signal to the sampling signal generation circuit IO, and the input signal from the AND circuit 9 generates a second sampling signal ■ having the same period and a different phase as the first sampling signal ■, and outputting the second sampling signal ■ to the sampling signal generating circuit IO. (b) Sampling signal generation circuit 10 outputting to 8
It is composed of

Next, an embodiment of the magnetic recording/reproducing apparatus according to the present invention will be described based on FIG.

Suppose now that the analog waveform (2) reproduced by the magnetic head 1 is reproduced and input in a disordered manner as shown by the broken line. This analog waveform (2) is input to the pulse shaper section 6 via the amplifier section 2. The integrating circuit 3 of the pulse shaper section 6 shapes a digital waveform (2) as shown by a broken line. The combination conditions of this digital waveform (2) and the first sampling signal (2) do not match, and the reproduction information (2) is extracted as reproduction information (including information reproduction errors).

When this playback information (including information playback errors) is transferred to a secondary device (not shown), it is determined that there is an error. As a result, the host device (not shown) issues a reread command and an off-nano 1-command (a command that does not even move the magnetic head up or down from a predetermined track position on the magnetic medium). Due to this offset command I, the offset plus signal and the offset 1-minus signal are simultaneously input to the AND circuit 9. The AND circuit 9 performs an AND operation on this signal and outputs the result to the sampling signal generation circuit 10, which generates a second sampling signal (2) and outputs it to the sampling circuit (b) 8.

At the time of revisiting, the sampling circuit (b) 8 collects the reproduced information by inputting the second sampling signal ■, and a switching circuit (not shown) in the sampling circuit (b) 8 switches from the first sampling signal ■ to the first sampling signal ■. Second sampling signal■
The second sampling signal is switched to the combination with ■
The normal reproduction information (2) sampled by the sampling circuit (b) 8 is outputted to the next circuit (not shown).

(g) Effects of the invention As described above, the advantage is that it is possible to provide a magnetic recording and reproducing device that makes it possible to prevent information reproduction errors caused by disturbances in the reproduced information waveform manually applied to the sampling circuit of the magnetic recording and reproducing device. be.

[Brief explanation of drawings]

FIG. 1 is an example of a conventional magnetic recording/reproducing device, FIG. 2 is a signal waveform situation at each point in FIGS. 1 and 3, and FIG. 3 is an example of a magnetic recording/reproducing device according to the present invention. are shown respectively. In the figure, 1 is a magnetic head, 12 is an amplifier section, 3 is an integration circuit, 4 is a differentiation circuit, 5 is a pulse shaper circuit, 6 is a pulse shaper section, 7 is a sampling circuit (a), 8 is a sampling circuit (b), 9 10 indicates an AND circuit, 10 indicates a sampling signal generation circuit, and 1 to 1 indicate each
The situations of the other Σ waveforms that fall at the points are shown respectively.

Claims (1)

[Claims] A second magnetic recording/reproducing device which reproduces information by sampling a signal read from a magnetic recording medium using a sampling signal having a predetermined period, and which generates a signal having the same period and a different phase as the sampling signal. A sampling signal generating means, and a sampling signal switching means for switching the sampling signal so that information is reproduced using a second sampling signal when a signal cannot be sampled during information reproduction using the sampling signal. magnetic recording and reproducing device.