JPS62175911A - Storage information reproducing circuit - Google Patents

Abstract

PURPOSE:To obtain a recording information reproducing circuit for generating no data error caused by noise, by providing an adjusting means for generating a delay signal which has given a prescribed delay to an output of an amplifying/ filter means, executing an addition of this delay signal and that which gives no delay, and outputting its result to a differential means. CONSTITUTION:A reproducing signal (a) which has been read from a magnetic head is amplified by an amplifier 1, and thereafter, a regular noise is eliminated through a filter 2, and said signal becomes a filter signal (b). A delaying circuit 3 delays the filter signal (b) by a prescribed time Td, and thereafter, inputs it as a delay signal (c) to an adder circuit 4. The adder circuit 4 adds the filter signal (b) and the delay signal (c), but the large noise which exists in the filter signal (b) becomes the noise whose phase is opposite to that of the delay signal (c), and after adding them, the unevenness becomes pretty small. Accordingly, in a differential signal (e), the noise which is lowered to a zero crossing point by only the filter signal (b) becomes uneven a little by adding the delay signal (c), and does not reach the zero crossing point, therefore, even after it has been inputted to a comparator, a data (g) can be detected normally.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a floppy disk device, and particularly to a stored information reproducing circuit thereof.

〔overview〕

The present invention provides a storage information reproducing circuit for reproducing data, including an amplifying/filtering means for amplifying and filtering a reproduced signal from a magnetic storage means and a differentiating means for generating a differential signal. By providing an adjustment means that generates a delayed signal by giving a predetermined delay to the output, adds this delayed signal to the above-mentioned original output without giving the delay, and outputs the result to the above-mentioned differentiating circuit, it is possible to eliminate noise caused by noise. This is to eliminate reading errors.

[Conventional technology]

Conventionally, the stored information reproducing circuit of this type of floppy disk device amplifies the reproduced signal from the magnetic head with an amplifier, removes noise with a filter, passes it through a differentiating circuit, and then converts the reproduced signal with a comparator or the like. The peak was detected and the data was reproduced.

[Problem that the invention seeks to solve]

The conventional storage information reproducing circuit described above has the disadvantage that if large noise is introduced into the reproduced signal due to static electricity or electrical noise, and the reproduced signal becomes distorted, this will be detected as a peak and a data error will occur. there were.

An object of the present invention is to provide a stored information reproducing circuit that does not cause data errors due to noise by eliminating the above-mentioned drawbacks.

[Means for solving problems]

The present invention provides a storage information reproducing circuit for reproducing data, which includes an amplifying/filtering means for amplifying and filtering a reproduced signal from a magnetic storage means and a differentiating means for generating a differential signal. The invention is characterized in that an adjustment means is provided for generating a delayed signal by giving a predetermined delay to the output, adding the delayed signal to the original output without giving the delay, and outputting the result to the differentiating means. .

(Function) The present invention generates a delayed signal by giving a predetermined delay to the reproduced signal that has been amplified and filtered by the amplification/filtering means, and combines this delayed signal with the original output that is not delayed. Addition is performed and the result is output to the differentiating means. The result of this addition is the same waveform shifted by a predetermined time and added as an opposite phase. Even if the waveform has a large noise added to the reproduced signal, its peak value will differ depending on the phase of the noise. can be made smaller than the original peak value of the reproduced signal. Therefore, even if there is large noise, a differential signal with a correct peak value can be obtained, and data errors can be prevented from occurring.

〔Example〕

Embodiments of the present invention will be explained below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

In this embodiment, a reproduced signal a from a magnetic head as a magnetic storage means is amplified and filtered by an amplifier 1 and a filter 2 as amplification/filtering means, and a filter signal from the filter 2 is given a predetermined delay. a delay circuit 3 that generates a delayed signal C; an adder circuit 4 that adds the delayed signal C and the filter signal d and outputs an added signal d;
and the addition circuit 4 constitute adjustment means. ) A differentiating circuit 5 as a differentiating means for differentiating the added signal d and outputting a differentiated signal e, and a differentiating circuit 5 as a differentiating means for differentiating the added signal d and outputting the differentiated signal e, and a predetermined reference signal (not shown) for the differentiated signal e.
The data shaping circuit 7 includes a comparison circuit that compares the comparison signal with a comparison signal f and outputs a comparison signal f, and a data shaping circuit 7 that formats the comparison signal and outputs data g in a predetermined form.

The feature of the present invention is that the delay circuit 3 and the adder circuit 4 are provided in FIG.

Next, the operation of this embodiment will be explained with reference to the operation timing chart shown in FIG. The reproduced signal a read by the magnetic head is amplified by an amplifier 1, and then passed through a filter 2, where normal noise is removed and a filtered signal S is obtained. The delay circuit 3 outputs the filter signal for a certain period of time Td.
After being delayed, the signal is input to the adder circuit 4 as a delayed signal C. The adder circuit 4 adds the delayed signal C to the filter signal, but as is clear from FIG. Although it depends on the phase of the noise, the unevenness becomes considerably smaller. Therefore, in the differential signal e,
If only the filter signal is used, the noise is enough to bring it down to the 0 cross point, but by adding the delayed signal C, it becomes small irregularities and does not reach the 0 cross point. Therefore, even after inputting this to the comparator, the data g does not reach the zero cross point. Detection becomes possible.

〔Effect of the invention〕

As explained above, in the present invention, by connecting an adjusting means consisting of a delay circuit and an adder circuit between the differentiating circuits, it is possible to remove large noises on the reproduced signal and eliminate reading errors caused by noises. effective.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. Figure 2 is an operation timing chart. ■...Amplifier, 2...Filter, 3...Delay circuit, 4...Addition circuit, 5...Differentiating circuit, 6...Comparator, 7...Data shaping circuit, a... - Reproduction signal, b...filter signal, i...delay signal, d...addition signal, e...differential signal, f...comparator signal, g...data. Patent applicant: NEC Corporation, /-1,:,,” '
. Agent Patent Attorney Nao Takashi Ide: (1゛■2 Example 2 Data g Figure

Claims (1)

[Claims] (1) In a stored information reproducing circuit for reproducing data, including amplifying/filtering means (1, 2) for amplifying and filtering a reproduced signal from a magnetic storage means and a differentiating means (5) for generating a differential signal. , adjustment means for generating a delayed signal by adding a predetermined delay to the output of the amplification/filtering means, adding the delayed signal to the original output without the delay, and outputting the result to the differentiating means; A stored information reproducing circuit characterized by providing (3, 4).