Dynamic magnetic information storage or retrieval – Automatic control of a recorder mechanism – Controlling the head
Reexamination Certificate
2000-08-01
2002-09-10
Hudspeth, David (Department: 2651)
Dynamic magnetic information storage or retrieval
Automatic control of a recorder mechanism
Controlling the head
Reexamination Certificate
active
06449115
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a memory unit which records or reproduces to-or-from a storage medium through a plurality of heads, and more particularly, to a memory unit in which a head assembly having the plurality of heads is connected with a printed circuit board having control circuits through lines.
2. Description of the Prior Art
Recently, electronic devices have been further miniaturized, and it is desired to also miniaturize a memory unit used for an external storage unit of a computer, etc. More specifically, in a magnetic disk unit which records and reproduces to-and-from a storage medium through a plurality of heads assembled in a head assembly, the number of lines connected between the head assembly and a printed circuit board having control circuits needs to be reduced.
FIG. 1
shows a schematic block diagram of an interface circuit of a conventional magnetic disk unit. A magnetic disk unit
11
shown in
FIG. 1
comprises a head assembly
12
for assembling a plurality of heads, a printed circuit board
15
for controlling the head assembly
12
, and a plurality of lines connecting between the head assembly
12
and the printed circuit board
15
.
In the head assembly
12
, differential-type heads
13
-
1
to
13
-
16
for recording and reproducing to-and-from a plurality of magnetic disks are assembled. Included in the head assembly
12
is a head IC
14
, which selects one of the heads
13
-
1
to
13
-
16
, and transmits-and-receives write-data and read-data. The head IC
14
is also fabricated on a flexible printed circuit board.
On the other hand, the plurality of lines between the head assembly
12
and the printed circuit board
15
comprise twelve lines which include, four head-selection signal lines
16
-
1
to
16
-
4
, write-data signal lines
17
-
1
,
17
-
2
, read-data signal lines
18
-
1
,
18
-
2
, a write-gate signal line
19
, a ground (GND) line
20
, and two-types (12 V and 15 V) power-supply lines
21
-
1
,
21
-
2
.
These signal lines are constructed by flexible print circuits (FPC) or flat cables, etc., between the printed circuit board
15
and the head assembly
12
.
For selecting one of the sixteen heads
13
-
1
to
13
-
16
, four-bit signals are needed. The above four head-selection signal lines
16
-
1
to
16
-
4
are set for these four-bit signals. In this way, a number of the head-selection signal lines is determined by a number of bits necessary for selecting one of heads.
FIG. 2
shows a connecting configuration of the interface circuit in the conventional magnetic disk unit shown in FIG.
1
. In an example shown in
FIG. 2
, the head assembly
12
is installed such that the sixteen heads
13
-
1
to
13
-
16
are close to magnetic disks
22
-
1
to
22
-
8
. Each of these heads
13
-
1
to
13
-
16
is mounted at the top of suspension gimbals
24
connected with a carriage
23
and can be moved in a radial direction of the magnetic disks
22
-
1
to
22
-
8
.
Two signal lines from each of the heads
13
-
1
to
13
-
16
are connected to associated pattern lines
26
on the flexible printed circuit board
25
through the suspension
24
and the carriage
23
. Each of the pattern lines
26
on the flexible printed circuit board
25
are routed to ports of the head IC
14
mounted thereon.
On the other side of the head IC
14
, each port of the head IC
14
is connected to an associated port of one side of an FPC
27
. Also on the other side of the FPC
27
, a connector
28
a
is assembled. In the FPC
27
, the above mentioned twelve lines,
16
-
1
to
16
-
4
,
17
-
1
,
17
-
2
,
18
-
1
,
18
-
2
,
19
, the GND line
20
, and the power-supply lines
21
-
1
,
21
-
2
, are formed by patterns
27
a
. Thick lines of the patterns
27
a
are allocated to the GND line
20
and the power-supply lines
21
-
1
,
21
-
2
.
On the other hand, the printed circuit board
15
for controlling and driving the magnetic disk unit
11
comprises a connector
28
b,
which is connected with the connector
28
a,
so as to connect between the printed circuit board
15
and the head assembly
12
.
To miniaturize the magnetic disk unit
11
, the number of lines between the printed circuit board
15
and the head assembly
12
also needs to be reduced. For this purpose, an example of reducing the number of connection lines by transmitting data in series is disclosed in Japanese Laid-open Pat. No.6-30505. In this example, a system, in which a main control unit is connected with a peripheral unit through a single data signal line and a single clock signal line, is disclosed. In this system, during one serial transmission, “information of data-transmit/receive directions”, “information of a data type”, and “information of data” are transmitted and received in that order.
To miniaturize the magnetic disk unit
11
, the width of the FPC
27
, namely the width of each pattern
27
a,
needs to be thinner. However, reducing the width of the pattern
27
a
any more causes noise due to voltage fluctuation. There is thus a problem that it is hard to miniaturize recording-and-reproducing units, such as a magnetic disk unit by thinning the width of each pattern
27
a
of the FPC
27
.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a memory unit. The size of the unit can be miniaturized by reducing the number of signal lines of the unit. Also, noise which may occur in the unit can be reduced. This permits the disadvantages described above to be eliminated.
The object described above is achieved by a memory unit having a plurality of heads performing at least one of recording or reproducing operations on a storage medium, the memory unit comprising: a first converter circuit for receiving head-selection signals as first parallel data and converting the head-selection signals to first serial data to be transmitted; a second converter circuit for receiving the first serial data from the first converter circuit and converting the first serial data to second parallel data to be transmitted; and a head control circuit for receiving the second parallel data from the second converter circuit and selectively driving the heads on the basis of the second parallel data.
In the above memory unit, the first converter circuit may be located on a printed circuit board controlling the memory unit, and the second converter circuit may be located inside a disk enclosure having the heads and the storage medium.
The object described above is also achieved by the memory unit mentioned above, wherein the memory unit further comprises a connecting circuit, including a line for the head-selection signal in the serial data form, for connecting the first converter circuit and the second converter circuit together, and the line has conductive patterns formed on a flexible material.
The object described above is also achieved by a memory unit having a plurality of heads performing at least one of recording or reproducing operations on a storage medium, the memory unit comprising: a first switching circuit for switching between transmission of record data to the heads and reception of reproduced data from the heads; and a second switching circuit for switching between reception of the record data from the first switching circuit and transmission of the reproduced data from the heads to the first switching circuit.
In the above memory unit, the first switching circuit may be located on a printed circuit board controlling the memory unit, and the second switching circuit may be located inside a disk enclosure having the heads and the storage medium.
The object described above is also achieved by the memory unit mentioned above, wherein the memory unit further comprises connecting circuit, including a line for the record data and the reproduced data, for connecting the first switching circuit and the second switching circuit together, and the line has a conductive pattern formed on a flexible material.
In the above memory units, the connecting circuit further comprises a first pattern of predetermined width a
Fujitsu Limited
Greer Burns & Crain Ltd.
Hudspeth David
Wong K.
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