Dynamic information storage or retrieval – Condition indicating – monitoring – or testing
Reexamination Certificate
2001-05-18
2003-04-01
Korzuch, William (Department: 2652)
Dynamic information storage or retrieval
Condition indicating, monitoring, or testing
Reexamination Certificate
active
06542449
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a disk drive apparatus for reading/writing information from/onto a disk-shaped storage medium (hereinafter referred to simply as a “disk”), such as an optical disk, a magnetic disk, and a magneto-optical disk, by using a pickup. More particularly, the present invention relates to a disk drive apparatus capable of cooling the pickup.
BACKGROUND OF THE INVENTION
In recent years, there has been an increasing demand for reducing the power consumption of a disk drive apparatus, due to the growing popularity of portable equipment using a disk drive apparatus and in view of the environment protection. A significant factor, among others, that increases the power consumption of a disk drive apparatus is the power consumed by the motor (disk motor) for rotating the disk.
In order to reduce the power consumption of a disk motor, it is important to reduce the windage loss, i.e., the load of an airflow generated by the rotation of the disk. When the disk is rotated, airflow is generated in the vicinity of the disk surface because the air surrounding the disk surface moves together with the rotating disk. The air flow gives some air resistance on the rotating disk surface. Furthermore, the disk rotates while slightly wobbling up and down. Therefore, the rotating disk takes relatively large air resistance. As the rotating disk takes the load of the surrounding air (or an airflow), the disk motor also takes some load, which increases the power consumption of the disk motor. Therefore, in order to reduce the power consumption of the disk motor, it is important to reduce the windage, loss on the rotating disk. In order to reduce the windage loss, it is effective to reduce the rotational speed of the disk, for example.
One approach known in the art to minimize the rotational speed of the disk while sufficiently retaining the performance of the apparatus, such as the data transfer rate, is to employ a CLV (Constant Linear Velocity) method for controlling the rotational speed of the disk. In the CLV method, the rotational speed of the disk is lower when reading/writing data from/onto a region of the disk closer to the outer periphery thereof, and higher when reading/writing data from/onto a region of the disk closer to the inner periphery thereof. The CLV method is suitably used with disk drive apparatuses for performing continuous reading/writing operations with little seek operation, such as music CD players. DVD-RAM writing/reading apparatuses suitably employ a ZCLV (Zoned CLV) method, in which different disk rotational speeds are used for a plurality of zones that are defined on the disk surface at different distances from the center of the disk, respectively. With these methods, it is possible to read/write information at a predetermined data transfer rate irrespective of the position of the pickup on the disk. Moreover, since the disk is rotated at the lowest rotational speed required to obtain the predetermined data transfer rate, the power consumption of the disk motor can be reduced.
When the disk drive apparatus is not writing/reading information (i.e., during an idling period), the disk drive apparatus is typically put in a sleep mode (power save mode) to save the power consumption, since putting the disk drive apparatus in such a mode during an idling period has little effect on the performance thereof. Japanese Laid-Open Patent Publication No. 8-255409 discloses a method for efficiently reducing the power consumption of the motor by decreasing the rotational speed of the disk motor in two steps in the sleep mode. Thus, it is possible to save the power consumption of the disk drive apparatus by reducing the rotational speed of the disk motor when a read/write operation is not being performed.
Japanese Laid-Open Patent Publication No. 11-185414 discloses a magnetic disk drive apparatus in which the magnetic head (pickup) is moved away from the center of the disk when a read/write operation is not being performed in order to reduce the windage loss on the rotating disk. According to Japanese Laid-Open Patent Publication No. 11-185414, when the head is near the outer periphery of the disk, as compared to when it is near the center of the disk, the airflow generated by the rotation of the disk is less likely to be disturbed, whereby it is possible to reduce the windage loss and thus the power consumption of the disk motor.
The conventional magnetic disk drive apparatus disclosed in Japanese Laid-Open Patent Publication No. 11-185414 will now be described with respect to FIG.
12
.
FIG. 12
illustrates a head disk assembly (hereinafter referred to as an “HDA”) of a magnetic disk drive apparatus
100
with a magnetic disk
101
loaded therein. The magnetic disk
101
, as a storage medium, is secured on the rotating member of a spindle motor
102
by a disk clamp
103
, so that the magnetic disk
101
is rotated by the rotation of the spindle motor
102
.
The magnetic disk drive apparatus
100
includes a magnetic head
104
for writing information onto the magnetic disk
101
. The magnetic head
104
is pivotally secured on a pivot
106
via a head arm
105
. The magnetic head
104
can be moved substantially in the radial direction of the magnetic disk
101
by moving the head arm
105
by using a voice coil motor
112
including a coil section
107
and a magnetic circuit
108
. The spindle motor
102
, the pivot
106
and the magnetic circuit
108
are secured to a base
109
.
The magnetic disk drive apparatus
100
rotates the magnetic disk
101
counterclockwise by driving the spindle motor
102
. The rotation of the magnetic disk
101
generates an airflow
110
in a direction according to the rotation direction of the magnetic disk
101
, as indicated by an arrow in FIG.
12
.
While the disk is rotating, the magnetic head
104
is moved as necessary between the outer periphery and the inner periphery of the magnetic disk
101
by pivoting the head arm
105
about the pivot
106
. When the magnetic head
104
is near the outer periphery of the magnetic disk
101
, a gimbal
111
and the head arm
105
are outside the magnetic disk
101
. In such a position, the gimbal
111
and the head arm
105
do not interfere with the passageway of the airflow
110
generated by the rotating magnetic disk
101
, thereby reducing the windage loss.
When the magnetic head
104
is at a position within the disk area that is not near the outer periphery of the magnetic disk
101
, the gimbal
111
and the head arm
105
as well as the magnetic head
104
are within the area of the magnetic disk
101
, thereby narrowing the passageway of the airflow
110
generated by the rotating magnetic disk
101
and thus disturbing the airflow
110
. As a result, the windage loss on the rotation of the magnetic disk
101
increases, thereby increasing the power consumption of the disk drive apparatus.
The operations of the magnetic head
104
, the spindle motor
102
, the voice coil motor
112
for moving the magnetic head
104
, etc., are controlled by an upper-level device (not shown). The upper-level device outputs signal for controlling the operations of the magnetic head
104
, the spindle motor
102
, etc., so as to read/write information from/onto the magnetic disk
101
. When the magnetic disk drive apparatus
100
receives a read command from the upper-level device, a seek operation is performed to move the magnetic head
104
to an intended track, and information is read by the magnetic head
104
from the intended track.
After completion of a read command, for example, the magnetic disk drive apparatus
100
performs a power saving operation as follows. If, after completion of the read command, the magnetic head
104
is on the inner periphery side with respect to a predetermined radial distance (e.g., a distance equal to two thirds of the radius of the magnetic disk
101
) from the center of the magnetic disk
101
, and if another command is not issued from the upper-level device within a predetermined period of time after the completion of the re
Mushika Yoshihiro
Nakatsuka Yoshiaki
Yamaguchi Hiroyuki
Akin Gump Strauss Hauer & Feld L.L.P.
Castro Angel
Korzuch William
LandOfFree
Disk drive apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Disk drive apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disk drive apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3094892