Magnetic tape apparatus including a circumferential surface having a generally flat portion between peak portions and method for producing the same
AssigneeSony Corporation
InventorHiroyuki Osaki
Life of this patent
Estimating the term…
Abstract
To lower the coefficient of static friction of the circumferential surface of the guide or drum constituting the magnetic tape apparatus. A flat portion is formed between peak portions. The peak portions and flat portion are formed so that the relationship: a′<a is satisfied, where “a” represents a distance between the ridges of the peak portions, i.e., pitch of the peak portions, and “a′” represents a bottom width of the peak portions. When this relationship is satisfied between the peak portions and the flat portion, the total area of the meniscuses formed between the magnetic tape and the peak portions can be reduced, thus making it possible to lower the coefficient of static friction.
Claims10
A magnetic tape apparatus for recording and/or reproducing information on a magnetic tape, the apparatus comprising:
- a drum comprising:
- a stationary drum portion including a sliding portion against which the magnetic tape is in sliding contact during operation of the apparatus;
- and
- a rotary drum portion rotatably connected to said stationary drum portion by a shaft, the rotary drum portion including a magnetic head for recording and/or reproducing information on said magnetic tape;
- wherein said sliding portion has a generally flat portion formed around a circumferential surface of said sliding portion so that the generally flat portion is substantially parallel to a sliding contact surface of said magnetic tape, and has plurality or peak portions formed around tho circumferential surface of the sliding portion so that said peak portions protrude from said fiat portion at a predetermined pitch;
- wherein said flat portion and said peak portions are formed so as to extend generally circumferentially around the stationary drum and to be substantially parallel to a lead formed in said stationary drum for guiding the magnetic tape as it slides along the sliding portion of the drum;
- wherein a surface roughness Rmax, defined as a maximum height of the peak portions, is between about 0.5 μm and about 2.0 μm;
- and
- wherein a width of said flat portion is between about 10 μm and about 230 μm.
A magnetic tape apparatus for recording and/or reproducing information on a magnetic tape, the apparatus comprising:
- a drum comprising:
- a stationary drum portion including a sliding portion against which the magnetic tape is in sliding contact during operation of the apparatus;
- and
- a rotary drum portion rotatably connected to said stationary drum portion by a shaft, the rotary drum portion including a magnetic head for recording and/or reproducing information on said magnetic tape;
- wherein said sliding portion has a generally flat portion formed around a circumferential surface of said sliding portion so the generally flat portion is substantially parallel to a sliding contact surface of said magnetic tape;
- wherein the sliding portion has a plurality of peak portions formed around the circumferential surface of the sliding portion so said peak portions protrude from said flat portion at a predetermined pitch;
- and
- wherein the flat portion has a concave form.
Dependencies are inferred from the claim text.