Magnetic recording apparatus having dust removing surface feature

A magnetic head is provided at its front end with respect to the surface of a magnetic disk with a stepped portion to cause a vortex of air stream so as to take dust away from the disk surface.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a magnetic recording apparatus for recording and 
reproducing data with a magnetic disk. 
2. Description of the Prior Art 
A prior art magnetic recording reproducing apparatus will now be described 
with reference to FIGS. 7 and 8. Referring to the figure, reference 
numeral 1 designates a magnetic disk rotatable by drive means (not shown), 
and 2 a magnetic head supported by suspension 3 and located over magnetic 
disk 1. Magnetic head 2 comprises head section 2a, to which electrical 
current is provided from a control unit (not shown), slider section 2b in 
contact with magnetic disk 1 and taper section 2c at the free end of 
slider section 2b. 
In operation, magnetic head 2 is held urged against magnetic disk 1 by 
spring force F of suspension 3. While disk 1 is stationary, slider section 
2b is held in contact therewith by spring force F. When disk 1 is rotated, 
head 2 acquires floating force H owing to air stream A generated with the 
rotation, and disk 1 is held floated with a slight gap with respect to 
disk 1 with equilibrium between floating force H and spring force F. In 
this state, head 2 performs recording or reproduction of data on or from 
disk 1 according to a signal from the control unit. 
With the above prior art magnetic recording apparatus, however, during high 
speed rotation of the magnetic disk the slider section of the head and 
disk are in contact with each other, and dust is generated from the disk 
surface. Dust thus generated remains in the vicinity of the disk surface 
and enters again into the gap between the slider section and disk, thus 
giving rise to a head crush or damage to the disk. 
SUMMARY OF THE INVENTION 
This invention seeks to solve the above problem, and its object is to 
provide a magnetic recording apparatus, in which generated dust is 
separated as much as possible from the surface of the magnetic disk to 
minimize dust entering the gap between the head slider section and disk so 
as to eliminate or reduce the head crush. 
According to the invention, there is provided a magnetic recording 
apparatus, which comprises a magnetic head located above a magnetic disk 
and floated from the same by an air stream generated by the rotation of 
the disk, and in which the head is provided on its front end portion with 
a laterally extending stepped portion facing the disk surface. 
The above and other objects, features and advantages of the invention will 
become more apparent from the following description when taken in 
conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
One embodiment of the invention will now be described with reference to 
FIGS. 1 to 3. Parts like those in FIGS. 7 and 8 are designated by like 
reference numerals, and their description is not given. Referring to the 
figures, reference numeral 4 designates stepped portion having or 
terminating in end surface 4a extending perpendicular to slider section 
2b. Stepped portion 4 extends laterally of magnetic head 2 and terminates 
in front end 2d of head 2, that is, it is provided on the side, from which 
air stream A enters the gap between the head and disk. Stepped portion 4 
has a height which may be at least ten times the gap between slider 
section 2b of head 2 and disk 1. The gap d between slider section 2b and 
head 1 as shown in FIG. 2, is several microns, so the height of stepped 
portion 4 may be several ten microns. Also, the depth of stepped portion 4 
may be several 100 microns. The height of taper section 2c is 5 to 6 
microns. 
In the above construction, magnetic head 2 is urged against magnetic disk 1 
by spring force F of suspension 3, and while disk 1 is stationary, slider 
section 2b is held in contact therewith by spring force F. When disk 1 is 
rotated, head 2 acquires floating force H due to air stream A generated 
with the rotation, and it is held floated with a slight gap from disk 1 
determined by equilibrium between floating force H and spring force F. In 
this state, head 2 records or reproduces data on or from disk 1 according 
to a signal from the control unit. 
Air stream A noted above is formed into vortex flow A1 at the front end of 
head 2 by stepped portion 4 thereof, thus taking dust 5 away from the 
surface of disk 1. Consequently, the amount of dust 5 entering the gap 
between slider section 2b of head 2 and disk 1 is substantially reduced. 
In this embodiment, stepped portion 4 with end surface 4a perpendicular to 
slider section 2b is provided at front end 2d of magnetic head 2 facing 
the magnetic disk. However, this is by no means limitative. For example, 
it is possible to provide projection 40 on front end 2d of magnetic head 
2, as shown in FIG. 4. As a further alternative, stepped portion 4 may 
have or terminate in acutely inclined end surface 4b as shown in FIG. 5. 
Further, stepped portion 4c may terminate in arcuately concavely curved 
end surface 4c as shown in FIG. 6 to enhance the effect of taking dust 5 
away. In general, any shape may be adopted so long as it permits dust 5 to 
be taken away. 
As has been described in the foregoing, according to the invention the 
magnetic head is provided at the front end with respect to the surface of 
the magnetic disk with a laterally extending stepped portion. It is thus 
possible to provide a highly reliable magnetic recording apparatus, in 
which air stream entering the gape between the magnetic head and magnetic 
disk is rendered into a vortex flow to take dust away from the disk 
surface, thus extremely reducing dust entering the gap between the slider 
section of the head and the disk thus eliminating or reducing the head 
crush.