JP2002288936A - Information reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information reproducing device, by which any of a plurality of information signals having different frequency bands can be accurately read and also which can speedily cope with a recording medium of larger capacity and higher density. SOLUTION: In the information reproducing device, by which a plurality of information signals having the different frequency bands are read from one or a plurality of recording media, filter circuits 17, 22 having different frequency characteristics are provided in accordance with the frequency bands of the information signals, and such a constitution is arranged that the information signal read from each recording medium is filtered and binarized by the filter circuit corresponding to each signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information reproducing apparatus capable of reading a plurality of information signals having different frequency bands from one or a plurality of recording media.

[0002]

2. Description of the Related Art In an information recording / reproducing apparatus which is widely and widely used, most removable devices capable of replacing a recording medium use a plurality of recording media (large-capacity medium and small-capacity medium) having different recording capacities. It has backward compatibility that operates on lower-order recording media so that it can be handled by the 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 kB) are used.
And a large capacity type ZIP drive device can read and write information signals from and to 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 recording capacity of the floppy disk described above (1.4).
4 MB and 720 kB), as well as the super-disc, super-standard (recording capacity 240 MB and recording capacity 12
0 MB) can be read and written by the same device.

FIG. 3 is a block diagram showing a conventional example of a super disk drive device. In particular, the periphery of an inductive head (preamplifier IC and R / R) for reading / writing information signals from / to a magnetic recording medium (super disk and floppy disk) is shown. (Around W channel IC).

The super disk drive shown in FIG. 1 has an inductive head L1 (hereinafter referred to as a first head L1) for reading and writing information signals from and to a super disk.
), And an inductive head L2 (hereinafter, referred to as a second head L2) for reading and writing information signals from and to a floppy disk, respectively, and these first and second heads L1, L2 are provided separately. Are externally connected to the preamplifier IC 70.

The preamplifier IC 70 amplifies the information signal read by the first head L1, an amplifier 71 that supplies a current corresponding to a write signal to the first head L1, and a read by the second head L2. An amplifier 73 for amplifying the read information signal, a write driver 74 for supplying a current corresponding to the write signal to the second head L2, and an amplifier 7
1 or 73 is connected to a coupling capacitor C
1, a selector 75 for sending to the next-stage R / W channel IC 80 via C2, a selection control of the amplifiers 71 and 73, a switching control of the selector 75, or the write drivers 72 and 7
And a control circuit 76 for controlling the transmission of a write signal to the control circuit 4. The selector 75 also has an amplification function as a second amplifier.

The R / W channel IC 80 includes a selector 75
Attenuator 81 that attenuates the information signal sent from
And an auto gain control circuit 82 (hereinafter, referred to as an auto gain control circuit) for adjusting the level of the information signal transmitted from the attenuator 81.
AGC circuit 82), a filter circuit 83 that filters and binarizes the information signal sent from the AGC circuit 82, and decodes a pulse signal sent from the filter circuit 83 while writing a write signal to the preamplifier IC 70. And a logic circuit 84 that performs transmission and the like.

[0008] Since the signal level of the information signal to be read is significantly different between when the super disk is reproduced and when the floppy disk is reproduced, when the information signal sent from the preamplifier IC 70 is directly input to the AGC circuit 82,
The operation of the AGC circuit 82 may become unstable. The attenuator 81 described above is provided with such an AGC circuit 82.
Is inserted for the purpose of preventing the unstable operation of the CPU, and its signal attenuation is controlled by an external CPU 90.
That is, the signal attenuation is reduced or set to 0 when reproducing a super disk having a low signal level, and conversely, the signal attenuation is increased when reproducing a floppy disk having a high signal level.

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.

[0010]

As explained above,
In the conventional super disk drive device, a signal processing path for reproducing a super disk and a signal processing path for reproducing a floppy disk are unified in the R / W channel IC 80, and signal processing (filtering and 2nd processing) for information signals read from both recording media is performed. Value) is performed by the common filter circuit 83.

Here, the recording density of the super disk handled by the super disk drive device 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 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.

Therefore, in order to unify signal processing for information signals read from both recording media, the frequency characteristic of the filter circuit 83 is broadened, and the frequency band of both information signals (several tens kHz to several tens MHz).

However, in order to broaden the frequency characteristics of the filter circuit 83, various problems such as deterioration of noise characteristics and signal accuracy, problems of the dynamic range and linearity of the filter circuit 83, and increase of current consumption are required. Must overcome. Therefore, if the recording medium (the super disk in the above example) achieves a further increase in capacity and density, it is technically necessary to increase the bandwidth of the filter circuit 83 provided in the R / W channel IC 80 in accordance with this. It has also become very difficult. Also,
Even if the bandwidth of the filter circuit 83 can be widened, the entire design of the filter circuit 83 needs to be redesigned, so that a long time is required for IC development and the cost of the IC increases.

In view of the above problems, the present invention can read out a plurality of information signals having different frequency bands with high precision, and can quickly increase the capacity and density of a recording medium. An object of the present invention is to provide an adaptive information reproducing apparatus.

[0015]

In order to achieve the above object, an information reproducing apparatus according to the present invention provides an information reproducing apparatus capable of reading a plurality of information signals having different frequency bands from one or a plurality of recording media. In the apparatus, at least two filter circuits having different frequency characteristics are provided corresponding to the frequency band of the information signal, and the information signal read from the recording medium is filtered and binarized by the filter circuit corresponding to each. .

In the information reproducing apparatus having the above configuration, it is preferable that a filter circuit corresponding to a predetermined information signal among the filter circuits is incorporated in a preamplifier IC for amplifying the information signal.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In the information reproducing apparatus according to the present invention, a super disk,
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. In particular, around an inductive head for reading and writing information signals from and to a magnetic recording medium (around a preamplifier IC and an R / W channel IC). Is shown.

The super disk drive shown in FIG. 1 includes an inductive head L1 (hereinafter, referred to as a first head L1) for reading and writing information signals on a recording medium having a high frequency characteristic such as a super disk, and a floppy disk. An inductive head L2 for reading and writing information signals on a recording medium having a low frequency characteristic, such as a disk.
(Hereinafter, referred to as a second head L2), respectively, and both the first and second heads L1, L2 are externally connected to the preamplifier IC 10. Various characteristics (head width and the like) of the first and second heads L1 and L2 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.

The preamplifier IC 10 amplifies an information signal read by the first head L1 and a coupling capacitor C which amplifies an output signal of the preamplifier 11.
1, a second amplifier 12 for sending to the next-stage R / W channel IC 20 via C2, a write driver 13 for supplying a current corresponding to a write signal to the first head L1, and information read by the second head L2. A preamplifier 14 for amplifying a signal, a second amplifier 15 for amplifying an output signal of the preamplifier 14, a write driver 16 for passing a current corresponding to a write signal to the second head L2, and a second amplifier 15
A filter circuit 17 for filtering and binarizing the output signal of the FD (hereinafter, referred to as an FD filter circuit 17); removing a miss pulse from an output pulse signal of the FD filter circuit 17; Time domain filter circuit 18 for sending to IC 20
(Hereinafter referred to as a TDF circuit 18), a preamplifier 11,
And a control circuit 19 for controlling the operation selection of the second and fourth amplifiers 12 and 15 and the transmission of write signals to the write drivers 13 and 16. The FD filter circuit 17 includes a filter and a comparator (both not shown).

The R / W channel IC 20 has an auto gain control circuit 21 (hereinafter, an AGC circuit 21) for adjusting the level of the information signal transmitted from the second amplifier 12.
), A filter circuit 22 for a super disk for filtering and binarizing the information signal sent from the AGC circuit 21 (hereinafter, referred to as an SD filter circuit 22).
While decoding the pulse signals sent from the TDF circuit 18 and the SD filter circuit 22,
And a logic circuit 23 for transmitting a write signal to C10. The logic circuit 23 is connected to an external CPU 30.

As described above, the F that filters and binarizes the information signal read from the floppy disk is used.
By separately providing the D filter circuit 17 and the SD filter circuit 22 for filtering and binarizing the information signal read from the super disk, the frequency characteristics of the FD filter circuit 17 and the SD filter circuit 22 can be improved. , Can be optimized according to the frequency band of the input information signal.

Therefore, the FD filter circuit 17 and the SD
It is not necessary to unnecessarily widen the frequency characteristic of the filter circuit 22 for use, and it is possible to easily resolve noise characteristic deterioration, signal accuracy deterioration, or the problem of dynamic range and linearity, thereby greatly facilitating IC design. . In other words, a plurality of information signals having different frequency bands can be read out with high accuracy. Further, since it is not necessary to insert an attenuator in a stage preceding the AGC circuit 21, it is possible to contribute to a reduction in circuit elements of the R / W channel IC 20.

As shown in the figure, the FD filter circuit 17 corresponding to the floppy disk as the lower-order recording medium may be incorporated not in the R / W channel IC 20 but in the preamplifier IC 10. With such a configuration, the preamplifier IC 10 can be used for all information reproducing apparatuses compatible with a floppy disk.
Can be used for general purposes. Also, if the higher-order recording medium achieves higher capacity and higher density,
Since only the design of the R / W channel IC 20 needs to be changed, quick adaptation is possible.

Next, a second embodiment of the super disk drive according to the present invention will be described. FIG. 2 is a block diagram showing a second embodiment of the super disk drive device according to the present invention. In particular, around an inductive head for reading and writing information signals from and to a magnetic recording medium (around a preamplifier IC and an R / W channel IC). Is shown.

The preamplifier IC 40 includes a preamplifier 41 for amplifying the information signal read by the first head L1 and a second amplifier 42 for amplifying the output signal of the preamplifier 41.
A write driver 43 for passing a current corresponding to a write signal to the first head L1, a preamplifier 44 for amplifying an information signal read by the second head L2, and a preamplifier 44
Amplifier 45, which amplifies the output signal of the second amplifier 45, a write driver 46 which supplies a current corresponding to the write signal to the second head L2, and a filter circuit 47 for a floppy disk which filters and binarizes the output signal of the second amplifier 45 , An FD filter circuit 47), and a selector 48 for transmitting one of the output signals of the second amplifier 42 and the FD filter circuit 47 to the next stage R / W channel IC 50 via the coupling capacitors C1 and C2. ,
And a control circuit 49 that controls operation selection of the preamplifiers 41 and 44 and the second amplifiers 42 and 45, switching control of the selector 48, and transmission control of write signals to the write drivers 43 and 46. The FD filter circuit 47 includes a filter and a comparator (both not shown).

The R / W channel IC 50 includes a selector 48
An automatic gain control circuit 51 (hereinafter, referred to as an AGC circuit 51) for adjusting the level of an information signal transmitted from the second amplifier 42 via the AGC circuit 51, and a super disc for filtering and binarizing the information signal transmitted from the AGC circuit 51 A filter circuit 52 (hereinafter, referred to as an SD filter circuit 52), a time domain filter circuit 53 (hereinafter, referred to as a TDF circuit 53) for removing a miss pulse from an output pulse signal of the FD filter circuit 47,
A logic circuit 54 that decodes the pulse signal sent from the filter circuit 52 and the TDF circuit 53 and sends a write signal to the preamplifier IC 40;
have. The logic circuit 54 is connected to an external CPU.
60.

As described above, in the super disk drive of the present embodiment, the TDF circuit 53 is connected to the preamplifier I.
This is a configuration provided in the R / W channel IC 50, not in the C40. Such a configuration is effective when a digital TDF circuit is used as the TDF circuit 53. Hereinafter, the reason will be described.

Generally, since the preamplifier IC 40 is constituted by an analog circuit, a clock source for operation must be newly provided to incorporate the digital TDF circuit 53. It is also necessary to take measures to prevent high frequency interference from affecting the analog circuits in the preamplifier IC 40. On the other hand, the R / W channel IC 50
Since the clock source for the operation of the logic circuit 54 is originally built in the TDF circuit 53, the TDF circuit 53 can use the clock source as it is. Therefore, preamplifier IC
There is no need to take any new interference prevention measures within 40.

Therefore, the digital TDF circuit 53
It can be said that it is more advantageous to incorporate it in the R / W channel IC 50 than to incorporate it in the preamplifier IC 40. Conversely, the analog TDF circuit may be incorporated in the preamplifier IC as described in the first embodiment.

As described above, in the super disk drive according to the present invention, the preamplifier IC and the R / W channel IC are not used, as shown in the first and second embodiments, but the preamplifier IC and the R / W channel IC are used. Since the block configuration can be arbitrarily determined between the IC and the / W channel IC, it is possible to select an optimum process for both ICs.

In the first and second embodiments described above,
In each case, a super disc drive device has been described as an example of an information reproducing device according to the present invention. However, the present invention is not limited to this. The present invention can be widely applied to an information reproducing apparatus that can read the information signal.

The number of R / W heads and the like may be arbitrarily set, and a configuration may be adopted in which filters for the front and back R / W heads of the recording medium are shared. Further, a preamplifier and a second amplifier provided in the preamplifier IC (for example, in the first embodiment, the preamplifier 11 and the second amplifier 12, and the preamplifier 14 and the second amplifier 15)
May be realized by one amplifier.

[0033]

As described above, in the information reproducing apparatus according to the present invention, in the information reproducing apparatus capable of reading a plurality of information signals having different frequency bands from one or a plurality of recording media, At least two filter circuits having different frequency characteristics are provided corresponding to the bands, and the information signal read from the recording medium is filtered and binarized by the filter circuit corresponding to each.

With this configuration, it is possible to optimize the frequency characteristics of the plurality of filter circuits according to the frequency band of the information signal input to each.
Therefore, it is not necessary to unnecessarily widen the frequency characteristics of each filter circuit, so that IC design becomes very easy. In addition, degradation of noise characteristics and signal accuracy, problems of dynamic range and linearity, increase of current consumption, etc. can be easily resolved, and multiple information signals with different frequency bands can be read with high accuracy. Becomes

In the information reproducing apparatus having the above configuration, it is preferable that a filter circuit corresponding to a predetermined information signal among the filter circuits is incorporated in a preamplifier IC for amplifying the information signal. In particular, a filter circuit corresponding to an information signal read from a downward compatible recording medium may be incorporated in the preamplifier IC.

With such a configuration, the preamplifier IC can be generally used for all information reproducing apparatuses that are compatible with lower-order recording media. In addition, when the higher-order recording medium achieves further increase in capacity and density, only the signal processing IC corresponding to the higher-order recording medium needs to be changed in design, so that quick adaptation is possible.

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

FIG. 3 is a block diagram showing a conventional example of a super disk drive device.

[Explanation of symbols]

10, 40 Preamplifier IC 11, 14, 41, 44 Preamplifier 12, 15, 42, 45 Second amplifier 13, 16, 43, 46 Write driver 17, 47 FD filter circuit 18, 53 Time domain filter circuit (TDF circuit) 19 , 49 Control circuit 20, 50 R / W channel IC 21, 51 Auto gain control circuit (AGC
Circuit) 22, 52 Filter circuit for SD 23, 54 Logic circuit 30, 60 CPU 48 Selector

Claims (2)

[Claims] An information reproducing apparatus capable of reading a plurality of information signals having different frequency bands from one or a plurality of recording media, wherein at least two filter circuits having different frequency characteristics corresponding to a frequency band of the information signal are provided. And an information reproducing apparatus, wherein the information signal read from the recording medium is filtered and binarized by a filter circuit corresponding to the information signal. 2. The information reproducing apparatus according to claim 1, wherein a filter circuit corresponding to a predetermined information signal among the filter circuits is incorporated in a preamplifier IC for amplifying the information signal.