Dynamic magnetic information storage or retrieval – General processing of a digital signal – Head amplifier circuit
Reexamination Certificate
2001-06-28
2004-07-13
Hudspeth, David (Department: 2651)
Dynamic magnetic information storage or retrieval
General processing of a digital signal
Head amplifier circuit
C360S066000, C360S067000
Reexamination Certificate
active
06762894
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a head apparatus, a hard disk apparatus and a recording and playback apparatus, and more particularly to a head apparatus which includes a recording head for recording information onto a recording medium and a playback head for playing back the recorded information, and a hard disk apparatus and a recording and playback apparatus wherein the head apparatus is used to record and play back information onto and from a hard disk.
A general configuration of a recording and playback apparatus for recording and playing back information onto and from a recording medium such as, for example, a hard disk drive (HDD) apparatus which uses a hard disk as a recording medium is shown in
FIG. 7. A
hard disk drive apparatus uses a magneto-resistive (MR) head (hereinafter referred to as MR head) as a playback head and uses an inductive head as a recording head. For example, a thin film (TF) head (hereinafter referred to as TF head) is known as the inductive head.
Referring to
FIG. 7
, a signal processing IC (read/write (R/W) IC)
201
having the functions of a playback amplifier and a recording driver is mounted on a flexible board
202
, and a head section
204
for recording/playing back onto/from a recording medium such as, for example, a hard disk
203
is carried on a suspension
206
mounted at a free end of a head arm
205
. The head section
204
is connected to the signal processing IC
201
by signal lines which extend through the suspension
206
, the head arm
205
, a head wiring line junction section
207
and the flexible board
202
.
FIG. 8
shows a basic configuration of the signal processing IC
201
. Referring to
FIG. 8
, the signal processing IC
201
includes a playback amplifier
211
, a recording driver
212
and a register circuit
213
built therein. The playback amplifier
211
is connected to a playback head such as, for example, an MR head
204
A through the head wiring line junction section
207
by two signal lines
214
and
215
, while the recording driver
212
is connected to a recording head such as, for example, a TF head
204
B through the head wiring line junction section
207
by two signal lines
216
and
217
.
A serial enable signal SENA, a serial clock signal SCLK and a serial data signal SDATA are inputted to the register circuit
213
. The register circuit
213
controls a bias current to the MR head section
204
A, a recording current to the TF head
204
B and so forth based on information given thereto with the serial data signal SDATA.
In recent years, the storage capacity of the HDD apparatus has increased suddenly, and also the data rate has increased in proportion to the increase of the storage capacity. Since a rise of the data rate raises the frequency band, an improvement of the S/N ratio is required inevitably.
However, while in the head apparatus for a HDD apparatus, normally a playback signal of several mv is transmitted from the MR head
204
A to the signal processing IC
201
, since the transmission line from the MR head
204
A to the signal processing IC
201
extends very long as can be seen from the foregoing description, the playback signal is liable to be influenced by disturbing noise. This causes a factor of deterioration of the S/N ratio.
Meanwhile, in the recording system, the sum of the inductance of the TF head
204
B and the inductance of the board on the transmission line serves as a load to the recording driver
212
. Thus, if the length of the transmission line from the signal processing IC
201
to the TF head
204
B is long, since the load to the recording driver
212
increases in accordance with the length of the transmission line, when the data rate rises as the storage capacity increases, the recording speed cannot follow up the data rate.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a head apparatus, which is tough against disturbing noise and superior in the S/N ratio, and which can cope with an increase of the capacity of a recording medium and a hard disk apparatus and a recording and playback apparatus, which employ the head apparatus.
In order to attain the object described above, according to an aspect of the present invention, there is provided a head apparatus comprising a support section for supporting a head section, a playback amplifier mounted on the support section for amplifying a playback signal outputted from the head section, a circuit section mounted on the support section for setting a bias current for the head section, a signal processing system provided outside the support section, and a transmission line for transmitting read data outputted from the playback amplifier to the signal processing system and transmitting serial data from the signal processing system to the circuit section.
According to another aspect of the present invention, there is provided a hard disk apparatus, comprising a hard disk, and a head apparatus including a head section for recording and playing back information onto and from the hard disk, the head apparatus further including a support section for supporting the head section, a playback amplifier mounted on the support section for amplifying a playback signal outputted from the head section, a circuit section mounted on the support section for setting a bias current for the head section, a signal processing system provided outside the support section, and a transmission line for transmitting read data outputted from the playback amplifier to the signal processing system and transmitting serial data from the signal processing system to the circuit section.
According to a further aspect of the present invention, there is provided a recording and playback apparatus, comprising a head apparatus including a head section for recording and playing back information onto and from a recording medium, the head apparatus further including a support section for supporting the head section, a playback amplifier mounted on the support section for amplifying a playback signal outputted from the head section, a circuit section mounted on the support section for setting a bias current for the head section, a signal processing system provided outside the support section, and a transmission line for transmitting read data outputted from the playback amplifier to the signal processing system and transmitting serial data from the signal processing system to the circuit section.
In the head apparatus, hard disk apparatus and recording and playback apparatus, since the playback amplifier and the circuit section are mounted together with the head section on the support section for the head section, a feeble playback signal outputted from the head section is amplified by the playback amplifier once and then transmitted to the signal processing system by the transmission line. This increases the relative level difference between the signal level of the playback signal being transmitted and the noise level of disturbing noise. As a result, the playback signal becomes tough against disturbing noise and the S/N ratio of the playback signal can be improved.
REFERENCES:
patent: 6219722 (2001-04-01), Tomita
patent: 6469857 (2002-10-01), Miyake
Narusawa Keiji
Shoji Norio
Davidson Dan I
Hudspeth David
Kananen Ronald P.
Rader & Fishman & Grauer, PLLC
Sony Corporation
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