JP2002230711A - Information reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that the unnecessary high frequency noise is amplified when the information signal of low band is amplified, since the frequency characteristics of an amplifier for amplifying the information signal is corresponded to the information signal of the highest band conventionally in an information reproducing device reading out a plurality of information signals having respectively different frequency bands from a magnetic recording medium. SOLUTION: This information reproducing device, by which a plurality of information signals having respectively different frequency bands are read out from the magnetic recording medium by using a magnetic head, is constituted in such a manner that the amplifiers 11, 12 having respectively different frequency characteristics corresponding to the frequency bands of the information signals are provided and these information signals are amplified respectively by the corresponding amplifiers 11, 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an information reproducing apparatus for reading a plurality of information signals having different frequency bands from a magnetic recording medium.

[0002]

2. Description of the Related Art In a magnetic information recording / reproducing apparatus which is widely used, most of removable devices capable of replacing a magnetic recording medium include a plurality of magnetic recording media having different recording capacities (large-capacity medium and small-capacity medium). Has the backward compatibility with the magnetic recording medium so that it can be handled by the same device. For example, in a floppy (registered trademark) disk drive device, two types of floppy disks (a recording capacity of 1.44 MB and a recording capacity of 720
An information signal can be read and written to and from a kB), and a ZIP drive device can read and write an information signal to and from two types of ZIP disks (recording capacity 250 MB and recording capacity 100 MB).

[0003] In particular, in a super disk drive apparatus which has recently been spotlighted as a next-generation magnetic information recording / reproducing apparatus, the above-mentioned floppy disk (recording capacity 1.44) is used.
The same device can read and write information signals not only for MBs and recording capacities of 720 kB) but also for super discs (recording capacities of 240 MB and recording capacities of 120 MB), which are higher standards.

FIG. 5 is a block diagram showing a conventional example of a super disk drive device, and particularly shows the vicinity (read side) of an inductive head for reading and writing information signals from and to a magnetic recording medium (super disk and floppy disk). ing.

The super disk drive shown in FIG. 1 has an inductive head 1 (hereinafter referred to as a first head 1) for reading and writing information signals from and to the super disk.
), An inductive head 2 (hereinafter referred to as a second inductive head) for reading and writing information signals from and to the floppy disk.
Head 2) are individually provided. Various characteristics (head width and the like) of the first and second heads 1 and 2 are optimized for a super disk and a floppy disk, respectively.

The super disk drive is provided with a preamplifier IC 10 'for amplifying each information signal read by the first head 1 or the second head 2. High-band amplifiers 11 'and 12' and a selector 13 'are incorporated in the preamplifier IC 10'.

As shown in FIG. 1, a first head 1 is connected between external terminals T1 and T2 of a preamplifier IC 10 ', and an information signal read by the first head 1 is amplified by a high-band amplifier 11'. After that, it is sent to the selector 13 '. On the other hand, the second head 2 is connected between the external terminals T3 and T4 of the preamplifier IC 10 '.
Is amplified by the high-band amplifier 12 'and then sent to the selector 13'.

The selector 13 'is connected to the high-band amplifier 11', 1
2 'is a circuit for sending only one of the output signals sent from 2' to an R / W channel IC (not shown) at the next stage, and its output terminals T5 and T6 are connected via coupling capacitors (not shown). Connected to the input terminal of the R / W channel IC. The selector 13 'receives a selection control signal from a control circuit (not shown) for controlling the operation of the super disk drive via an external terminal T7, and the selector 13' operates based on the selection control signal. The output signal is selected.

With the above configuration, the same device can read and write information signals not only on a floppy disk but also on a super disk, which is a higher-order standard, in the super disk drive.

FIG. 6 is a block diagram showing another conventional example of a super disk drive, and shows the periphery of an inductive head (read side) for reading and writing information signals from and to a magnetic recording medium as in FIG. Note that the same parts as those in FIG.

A selector 11 "and a high-band amplifier 12" are incorporated in a preamplifier IC 10 "shown in FIG. The selector 11 ″ sends only one of the information signal read by the first head 1 and the information signal read by the second head 2 to the high-band amplifier 12 ″. The high-band amplifier 12 ″ amplifies the information signal input from the selector 11 ″, and the next-stage R / W channel IC
(Not shown). With such a configuration, the number of high-bandwidth amplifiers is reduced as compared with the conventional example shown in FIG.

Here, the recording density of the super disk handled by the super disk drive having the above configuration is much higher than the recording density of the floppy disk, and the amount of information signals recorded on the same track length is also smaller than that of the floppy disk. And very big. Therefore, while the frequency band of the information signal read from the floppy disk (small capacity medium) is as low as several tens of kHz to several hundreds kHz, the frequency band of the information signal read from the super disk (large capacity medium) is Has a very high band of several MHz to several tens of MHz.

When reading such information signals having different frequency bands by the same device, the preamplifier ICs 10 ', 1'
0 '', the first head 1 for the super disk and the second head 2 for the floppy disk are connected to the external terminals T1,
The high-bandwidth amplifier 1 shown in FIG. 5 has a structure that can be connected between T2 and between the external terminals T3 and T4.
1 ', 12' or the high-bandwidth amplifier 1 shown in FIG.
The frequency characteristics (frequency-gain characteristics) of 2 '' have all become high bands corresponding to the frequency band of the information signal recorded on the super disk.

FIG. 7 is a frequency characteristic diagram of the high band amplifiers 11 'and 12' and the high band amplifier 12 ''. Note that the horizontal axis of the figure indicates the frequency (Hz), and the vertical axis indicates the gain of each amplifier. As described above, the high-bandwidth amplifier 1
The frequency-gain characteristics (solid line L1) of 1 ′, 12 ′ and the high-band amplifier 12 ″ are set to a high band corresponding to the frequency band (several MHz to several tens MHz) of the information signal recorded on the super disk. (The cutoff frequency is set to several tens of MHz or more.)

The preamplifier IC 10 'having the above structure,
If it is 10 '', the first head 1 for the super disk
And the second head 2 for a floppy disk may be connected between the external terminals T1 and T2 and between the external terminals T3 and T4, so that the degree of freedom of wiring is high and erroneous connection of the magnetic head does not occur. . Therefore, it is easy to assemble the set of the super disk drive device, and it is easy to perform the product inspection and the like.

[0016]

However, in the super disk drive having the above structure, as described above, the frequency band of the information signal read from the floppy disk is as low as several tens kHz to several hundreds kHz. Regardless, the frequency characteristics of the high-band amplifier 12 ′ and the high-band amplifier 12 ″ are changed according to the frequency band (several MHz to several tens MH) of the information signal recorded on the super disk.
The band is set to a high band corresponding to z). Therefore, the low-band information signal read from the floppy disk is unnecessarily amplified by the high-band amplifier 12 'or the high-band amplifier 12''operating in the high band.

In such a configuration, when reproducing the floppy disk, not only the originally required low-band information signal but also high-frequency noise generated from outside or inside the device is picked up and unnecessarily amplified. The high-frequency noise may adversely affect the reproduction operation of the floppy disk.

For this reason, the super disk drive (particularly, around the second head 2) is provided with a magnetic shield (not shown) for reducing high-frequency noise, or a signal line damping element (not shown) on a printed circuit board. ) Must be added, and such an increase in the number of parts has led to an increase in the cost of the apparatus.

In view of the above problems, an object of the present invention is to provide an information reproducing apparatus capable of reading out a plurality of information signals having different frequency bands with high accuracy.

[0020]

In order to achieve the above object, an information reproducing apparatus according to the present invention uses an inductive head to read a plurality of information signals having different frequency bands from a magnetic recording medium. , A plurality of amplifiers having different frequency characteristics are provided corresponding to the frequency band of the information signal, and the information signal read from the magnetic recording medium is amplified by the amplifier corresponding to each.

Alternatively, in an information reproducing apparatus for reading a plurality of information signals having different frequency bands from a magnetic recording medium using an inductive head, a frequency characteristic of an amplifier for amplifying the information signal read from the magnetic recording medium may be changed by changing the frequency characteristic of the information signal. May be changed according to the frequency band.

In the information reproducing apparatus having the above-described configuration, it is preferable that a plurality of inductive heads having different characteristics are provided corresponding to the magnetic recording medium.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION In the information reproducing apparatus according to the present invention, a super disk is used as a high-capacity medium.
A description will be given by taking a super disk drive device capable of using a floppy disk as a small capacity medium as an example. FIG. 1 is a block diagram showing a first embodiment of a super disk drive according to the present invention, and particularly shows the periphery of an inductive head (read-side preamplifier IC) for reading / writing information signals from / to a magnetic recording medium. .

The super disk drive shown in FIG. 1 includes an inductive head 1 (hereinafter, referred to as a first head 1) for reading and writing information signals on a medium having a high frequency characteristic such as a super disk, and a floppy disk. And an inductive head 2 (hereinafter, referred to as a second head 2) for reading and writing an information signal on a medium having a low frequency characteristic. Various characteristics (head width and the like) of the first and second heads 1 and 2 are optimized for a super disk and a floppy disk, respectively. With such a configuration, it is possible to read and write the information signal with respect to the super disk and the floppy disk with high accuracy.

Further, the super disk drive device is provided with a preamplifier IC 10 for amplifying each information signal read by the first head 1 or the second head 2. Inside the preamplifier IC 10, a high-band amplifier 11, a low-band amplifier 12, and a selector 13 are incorporated. The frequency-gain characteristics of the high-band amplifier 11 and the low-band amplifier 12 will be described later in detail.

As shown in FIG. 1, the first head 1 is connected between the external terminals T1 and T2 of the preamplifier IC 10, and the information signal read by the first head 1 is amplified by the high-band amplifier 11. Thereafter, it is sent to the selector 13. On the other hand, the second head 2 is connected between the external terminals T3 and T4 of the preamplifier IC 10, and the information signal read by the second head 2 is amplified by the low-band amplifier 12 and then transmitted to the selector 13. .

The selector 13 is a circuit for sending either the output signal sent from the high-band amplifier 11 or the low-band amplifier 12 to the R / W channel IC 40 at the next stage, and its output terminals T5 and T6 are coupling capacitors. C1, C
2, the input terminals TA, T of the R / W channel IC 40
B. The selector 13 is supplied with a selection control signal from a control circuit (not shown) for controlling the operation of the super disk drive via an external terminal T7, and the selector 13 outputs an output signal based on the selection control signal. Is performed.

The R / W channel IC 40 is a preamplifier IC
This is a circuit for binarizing the information signal amplified by 10 and outputting it. An auto gain control circuit 41 (hereinafter, referred to as an AGC circuit 41), a programmable filter 42, and a binarization circuit 43 are incorporated in the R / W channel IC 40.

The information signal input to the R / W channel IC 40 is sent to a programmable filter 42 after its voltage level is fixed by an AGC circuit 41. The programmable filter 42 slims the information signal,
The superimposed high-frequency noise is removed. The binarization circuit 43 uses the information signal from which the high-frequency noise has been removed by the programmable filter 42 as a pulse signal, and sends the pulse signal to a decoding processing circuit (not shown) via the external terminals TC and TD.

Next, the frequency-gain characteristics of the high-band amplifier 11 and the low-band amplifier 12 will be described. FIG. 2 is a frequency characteristic diagram of the high-band amplifier 11 and the low-band amplifier 12. Note that the horizontal axis of the figure indicates the frequency (Hz), and the vertical axis indicates the gain of each amplifier.

As described above, since the recording density of the super disk (large capacity medium) is much higher than that of the floppy disk (small capacity medium), the frequency band of the information signal read from the floppy disk is several tens kHz. The frequency band of the information signal read from the super disk is as high as several MHz to several tens of MHz, whereas the frequency band is as low as several hundred kHz.

Therefore, in the super disk drive device according to the present embodiment, the frequency-gain characteristic (solid line L1) of the high-band amplifier 11 is changed to the frequency band (several MHz to several tens MH) of the information signal recorded on the super disk as before.
z), the frequency band is set to a high band (the cutoff frequency is set to several tens of MHz or more), while the frequency-gain characteristic (broken line L2) of the low band amplifier 12 is set to the value of the information signal recorded on the floppy disk. A low band is set (the cutoff frequency is set to about several MHz) corresponding to the frequency band (several tens kHz to several hundred kHz).

As described above, by providing the high-band amplifier 11 and the low-band amplifier 12 having different frequency characteristics in accordance with the frequency band of the information signal, and amplifying each information signal by the corresponding amplifier. The information signal read from the super disk or the floppy disk can be properly amplified.

More specifically, when amplifying a low-band information signal read from a floppy disk (a low-capacity medium), unnecessary amplification of high-frequency noise included in a hatched portion in the drawing may occur. Therefore, it is possible to reduce the interference of high-frequency noise and perform a floppy disk reproduction operation with higher accuracy than before.

Therefore, in the super disk drive device of the present embodiment, the magnetic shield and the signal line damping element to the printed circuit board for reducing high-frequency noise can be reduced or unnecessary, so that the cost of the device can be reduced. Can be planned.

Next, a second embodiment of the super disk drive according to the present invention will be described. FIG. 3 is a block diagram showing a second embodiment of the super disk drive according to the present invention, and particularly shows the periphery of an inductive head (read-side preamplifier IC) for reading / writing information signals from / to a magnetic recording medium. . The first
The same parts as those in the embodiment are denoted by the same reference numerals as those in FIG.

Inside the preamplifier IC 20 in this embodiment, the band variable amplifiers 21 and 22 and the selector 2
3 are incorporated. Further, the preamplifier IC 20 is provided with a band adjustment circuit 24 for changing the frequency characteristics of the band variable amplifiers 21 and 22. A band control signal is input to the band adjustment circuit 24 from a control circuit (not shown) for controlling the operation of the super disk drive via an external terminal T8, and the band adjustment circuit 24 performs the operation based on the band control signal. The frequency-gain characteristics of the band variable amplifiers 21 and 22 are changed. Note that the band variable amplifier 2
The frequency-gain characteristics of 1 and 22 may be step-variable or linear-variable.

For example, a first head 1 for a super disk (large-capacity medium) is connected between the external terminals T1 and T2, and a second head 2 for a floppy disk (small-capacity medium) is connected between the external terminals T3 and T4. If connected, the frequency-gain characteristic of the band variable amplifier 21 is set to a high band (solid line L1 in FIG. 2), and the frequency-gain characteristic of the band variable amplifier 22 is set to a low band (dashed line L2 in FIG. 2).

Conversely, the first head 1 for a super disk (large capacity medium) is connected between the external terminals T3 and T4,
If the second head 2 for a floppy disk (small capacity medium) is connected between the external terminals T1 and T2, the frequency-gain characteristic of the band variable
And a frequency-gain characteristic of the band variable amplifier 22 is set to a high band (solid line L1 in FIG. 2).

As described above, by changing the frequency characteristic of the amplifier for amplifying the information signal according to the frequency band of the information signal, the information signal read from the super disk or the floppy disk can be properly amplified. Can be.

More specifically, when amplifying a low-band information signal read from a floppy disk (low-capacity medium), it is unnecessary to amplify high-frequency noise included in the hatched portion in FIG. Therefore, it is possible to reduce the interference of high-frequency noise and perform a floppy disk reproduction operation with higher accuracy than before.

Therefore, in the super disk drive device of the present embodiment, the magnetic shield and the signal line damping element for the printed circuit board for reducing high frequency noise can be reduced or made unnecessary, so that the cost of the device can be reduced. Can be planned.

Further, in the case of the super disk drive device according to the present embodiment, the first head 1 for the super disk and the second head 2 for the floppy disk are connected between the external terminals T1 and T2 in the same manner as in the prior art. External terminal T
3 and T4 may be connected, so that the degree of freedom of wiring is high. Therefore, it is easy to assemble the set of the super disk drive device, and it is easy to perform the product inspection and the like.

Next, a third embodiment of the super disk drive according to the present invention will be described. FIG. 4 is a block diagram showing a third embodiment of the super disk drive according to the present invention, and particularly shows the periphery of an inductive head (read-side preamplifier IC) for reading / writing information signals from / to a magnetic recording medium. . In addition,
The same parts as those in the first embodiment are denoted by the same reference numerals as those in FIG.

The selector 31 and the band variable amplifier 32 are incorporated in the preamplifier IC 30 in this embodiment. The selector 31 sends only one of the information signal read by the first head 1 and the information signal read by the second head 2 to the band variable amplifier 32.

The preamplifier IC 30 is provided with a band adjusting circuit 33 for changing the frequency-gain characteristics of the band variable amplifier 32. A band control signal is input to the band adjusting circuit 33 from a control circuit (not shown) for controlling the operation of the super disk drive via an external terminal T8, and the band adjusting circuit 33 receives the band control signal based on the band control signal. The frequency-gain characteristics of the band variable amplifier 32 are changed. Note that the frequency-gain characteristics of the band variable amplifier 32 may be step variable or linear variable.

For example, when the high-band information signal read from the super disk is selected by the selector 31, the frequency-gain characteristic of the band variable amplifier 32 is set to the high band (solid line L1 in FIG. 2). When the low-band information signal read from the floppy disk is selected by the selector 31, the frequency-gain characteristic of the band variable amplifier 32 is set to the low band (broken line L2 in FIG. 2).

As described above, by changing the frequency characteristic of the amplifier for amplifying the information signal according to the frequency band of the information signal, the information signal read from the super disk or the floppy disk can be properly amplified. Can be.

More specifically, when amplifying a low-band information signal read from a floppy disk (low-capacity medium), it is unnecessary to amplify high-frequency noise included in the hatched portion in FIG. Therefore, it is possible to reduce the interference of high-frequency noise and perform a floppy disk reproduction operation with higher accuracy than before.

Therefore, in the super disk drive of the present embodiment, a magnetic shield for reducing high frequency noise and a signal line damping element to a printed circuit board can be reduced or eliminated, thereby reducing the cost of the apparatus. Can be planned.

Further, in the super disk drive device according to the present embodiment, the first head 1 for the super disk and the second head 2 for the floppy disk are connected to the external terminals T1 and T2 in the same manner as in the prior art. External terminal T
3 and T4 may be connected, so that the degree of freedom of wiring is high. Therefore, it is easy to assemble the set of the super disk drive device, and it is easy to perform the product inspection and the like.

In addition, the super disk drive of the present embodiment can reduce the number of amplifiers and reduce the circuit scale as compared with the super disk drive of the first and second embodiments. Can be planned.

In the first to third embodiments described above,
In both cases, the description has been made by taking a super disk drive device as an example of the information reproducing device according to the present invention, but the present invention is not limited to this, and each of the frequency bands is separated from the magnetic recording medium using an inductive head. The present invention can be widely applied to an information reproducing apparatus that reads a plurality of different information signals.

In the second and third embodiments described above,
The band adjustment circuits 24 and 33 are both preamplifier IC2
Although the description has been given by giving an example of a configuration in which the band adjustment circuits 24 and 33 are incorporated inside the preamplifier IC2,
0 and 30 may be provided outside.

[0055]

As described above, in the information reproducing apparatus according to the present invention, in the information reproducing apparatus for reading a plurality of information signals having different frequency bands from a magnetic recording medium using an inductive head, A plurality of amplifiers having different frequency characteristics are provided corresponding to the frequency bands, and the information signal read from the magnetic recording medium is amplified by the corresponding amplifier. With this configuration, the information signals read from the plurality of magnetic recording media can be appropriately amplified.

More specifically, since the low-band information signal read from the low-capacity medium is not unnecessarily amplified by the amplifier operating in the high-band, the interference of the high-frequency noise is reduced to reduce the interference. It is possible to perform the operation of reproducing a low-capacity medium with higher accuracy than before. Therefore, in the information reproducing apparatus having the above configuration, the number of magnetic shields for reducing the high-frequency noise, the signal line damping element to the printed board, and the like can be reduced, so that the cost of the apparatus can be reduced.

Alternatively, in an information reproducing apparatus for reading a plurality of information signals having different frequency bands from a magnetic recording medium by using an inductive head, the frequency characteristic of an amplifier for amplifying the information signal read from the magnetic recording medium may be changed to the information signal. May be changed according to the frequency band. With such a configuration, in addition to the above effects, the degree of freedom of wiring can be increased. Therefore, it is easy to assemble the set of the information reproducing apparatus and to perform the product inspection and the like.

In the information reproducing apparatus having the above-mentioned configuration, it is preferable that a plurality of inductive heads having different characteristics are provided corresponding to the magnetic recording medium. With such a configuration, it is possible to read and write information signals on the super disk and the floppy disk with high accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a super disk drive according to the present invention.

FIG. 2 is a frequency characteristic diagram of a high-band amplifier 11 and a low-band amplifier 12.

FIG. 3 is a block diagram showing a second embodiment of the super disk drive according to the present invention.

FIG. 4 is a block diagram showing a third embodiment of the super disk drive according to the present invention.

FIG. 5 is a block diagram showing a conventional example of a super disk drive device.

FIG. 6 is a block diagram showing another conventional example of a super disk drive.

FIG. 7 is a frequency characteristic diagram of the high-band amplifiers 11 ′ and 12 ′ and the high-band amplifier 12 ″.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 Inductive head for super disk (first head) 2 Inductive head for floppy disk (second head) 10 preamplifier IC 11 high band amplifier 12 low band amplifier 13 selector 20 preamplifier IC 21 variable band amplifier 22 variable band amplifier 23 selector 24 Band adjustment circuit 30 Preamplifier IC 31 Selector 32 Band variable amplifier 33 Band adjustment circuit 40 R / W channel IC 41 Auto gain control circuit (AGC circuit) 42 Programmable filter 43 Binarization circuit

Claims (3)

[Claims] 1. An information reproducing apparatus for reading a plurality of information signals having different frequency bands from a magnetic recording medium using an inductive head, comprising: a plurality of amplifiers having different frequency characteristics corresponding to the frequency bands of the information signals; An information reproducing apparatus, wherein an information signal read from the magnetic recording medium is amplified by the corresponding amplifier. 2. An information reproducing apparatus for reading a plurality of information signals having different frequency bands from a magnetic recording medium using an inductive head, wherein the information signal has a frequency characteristic of an amplifier for amplifying the information signal read from the magnetic recording medium. An information reproducing apparatus characterized in that the information reproducing apparatus changes according to the frequency band of the information. 3. The information reproducing apparatus according to claim 1, wherein a plurality of inductive heads having different characteristics are provided corresponding to the magnetic recording medium.