Classifications

• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
  • G11B15/02—Control of operating function, e.g. switching from recording to reproducing
  • G11B15/05—Control of operating function, e.g. switching from recording to reproducing by sensing features present on or derived from record carrier or container
  • G11B15/06—Control of operating function, e.g. switching from recording to reproducing by sensing features present on or derived from record carrier or container by sensing auxiliary features on record carriers or containers, e.g. to stop machine near the end of a tape
  • G11B15/08—Control of operating function, e.g. switching from recording to reproducing by sensing features present on or derived from record carrier or container by sensing auxiliary features on record carriers or containers, e.g. to stop machine near the end of a tape by photoelectric sensing
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B23/00—Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus ; Intermediate mediums; Apparatus or processes specially adapted for their manufacture
  • G11B23/02—Containers; Storing means both adapted to cooperate with the recording or reproducing means
  • G11B23/04—Magazines; Cassettes for webs or filaments
  • G11B23/049—Cassettes for special applications not otherwise provided for
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
  • G11B27/36—Monitoring, i.e. supervising the progress of recording or reproducing
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
  • G11B5/41—Cleaning of heads

Definitions

• the invention relates to a method for cleaning the magnetic head of a magnetic tape read / write device and a device for carrying out the method, in which a cleaning tape is guided along the magnetic head.
• the invention further relates to a magnetic tape.
• the abrasion forms an undesirable ramp / which leads to the magnetic tape being lifted off the magnetic head, so that the magnetic recording or reading out is no longer reliable.
• the invention is based on the object of specifying methods and a device of the type mentioned at the outset with which operation which is gentle on the magnetic head and good tape contact is possible.
• the cleaning agent preferably consists of a mechanically acting scouring agent.
• chemically active, cleaning-active substances can also be present.
• Mechanical and chemical coatings which are particularly suitable for cleaning magnetic heads are known from those cleaning tapes which are commercially available in separate cassettes.
• the great advantage achieved by the invention is that the magnetic head can be cleaned without the tape carrying data information having to be removed from the read / write device.
• the decision at which point in time and in what time period the cleaning process is carried out can be determined by evaluating the stored data with the aid of an error detection method.
• the cleaning tape section is transparent.
• the read / write device identifies the cleaning belt section as a belt follow-up, as is otherwise characterized by the usual standard follow-up belt section.
• the cleaning belt section can therefore replace the standardized trailing belt section.
• the cleaning belt section is arranged after the standard trailing belt section. This ensures that the cleaning belt section can only be put into operation via a special control. In order to ensure that there is sufficient overrun even when the cleaning belt section is fully utilized, it is advantageous to provide a further tracking belt section as the belt end.
• the cleaning belt section and the trailing belt section are formed in one piece, i.e. the transparent plastic strip in question is only partially coated with cleaning agent.
• a cleaning tape section of approximately 30 cm in length is present in the case of a band section coated with magnetizable material that is approximately 30 m long.
• Such a length of the cleaning tape section is thus sufficient to clean all of the required magnetic heads within the average lifetime of the magnetic tape or a tape cassette to carry out. Since the cleaning tape section is part of the cassette, it can be dimensioned so that it becomes unusable with the "natural" aging or wear of the cassette.
• FIG. 1 schematically shows a magnetic tape
• Figure 2 shows schematically a magnetic tape cassette
• Magnetic head drum, and Figure 3 shows a circuit arrangement for controlling the
• FIG. 1 schematically illustrates a strip-shaped data carrier 10. as it is used in so-called magnetic tape cassettes for data processing as data and program memory.
• the data carrier 10 is composed in the longitudinal direction of various tape sections, which are glued to each other on their end faces.
• Plastic serves as the base material for the individual strip sections.
• a tape start 15 is defined by the fact that when it is arranged within a standard data cassette (FIG. 2) it is attached to an empty cassette take-up reel 17 in the initial state of the data cassette. Analogously, the tape end 16 is attached to a full unwind spool 18 in the initial state. The forward running direction is indicated by arrow 19.
• the tape start side of the data carrier 10 is determined in that the loading program parts are recorded in this tape area, while the actual user data are recorded on the remaining tape surface. The recording of data takes place via inclined tracks 20, as are shown schematically for the sake of completeness at the beginning of a tape section 12 coated with a magnetizable material. As FIG.
• this tape section 12 there is an uncoated, transparent follow-up tape section 14.
• a cleaning tape section 13 which coats with a mechanically acting cleaning agent for cleaning a magnetic head (FIG. 2) of the read / write device is.
• another, uncoated, transparent follow-up belt section 21 is provided at the end of the belt.
• the cleaning tape section 13 can be transparent or opaque.
• the data carrier 10 is located in a plastic cassette 22, which is shown with the upper side partially cut open.
• the data carrier 10 is guided past a rotating magnetic head drum 23, which is provided, for example, with two or four magnetic heads 24 in the region of the drum surface.
• the magnetic head drum 23 is inclined to the running direction of the data carrier 10, so that the inclined tracks 20 described in FIG. 1 are generated during the data recording.
• the magnetic head drum 23 is part of a read / write unit 25 of a data processing device.
• the magnetic heads or the magnetic head drum 23 is connected to an electronic evaluation unit 26 with which the data read out from the data carrier 10 are evaluated for bit errors, block errors, track errors, slip errors etc.
• the cause of the error can be determined on the basis of the type of error determined, taking into account the characteristic differences in length of the errors. If, for example, a data error has occurred due to a defect in the modulation circuit, it is usually a few bits in length. After a short time, the demodulator resumes synchronization and the fault has ended.
• the entire track will generally not be readable because the accumulated contamination,. for example, pieces of metal dust while the entire data track rests on the magnetic head 24. Only when the magnetic head drum 23 is rotated again can it be thrown away by the centrifugal force. It is also typical for a block error that the adjacent data track is not affected by the error, since another magnetic head 24 'reads this next track. This applies analogously also in the event that there is a contamination ramp on a magnetic head 24 '.
• the reliable detection of the type of error also contributes to the fact that several read attempts are made and / or that error statistics are drawn up, for example in order to detect tape wear.
• E 1 the error length is larger than a data block
• FIGS. 1 to 3 A cleaning process is explained below using FIGS. 1 to 3 as an example.
• the evaluation unit -26 controls the end of the tape via a cassette drive 27, which acts on the take-up spool 17 or the take-up spool 18.
• the transparent trailing belt section 14 is detected by an optoelectronic scanning unit 28.
• the cleaning tape is cut 23 controlled and guided past the relevant magnetic head 24 for a predetermined time.
• the magnetic head 24 is cleaned by the mechanical friction.
• the magnetic head drum 23 can also be set in motion by a predetermined number of revolutions with frictional contact with the cleaning tape section 13.
• the tape section 12 is driven to continue the write / read process.
• the data processing device in question remains ready for operation during the entire cleaning process, i.e. it is available, for example, for a host system.
• An optical display unit 29 can be used to signal the operator that a cleaning process is being carried out or has been carried out during operation. For the rest, it is expedient to log the cleaning processes at least in number and to store corresponding information on the data carrier 10. On the basis of this data, different areas of the cleaning belt section 13 are controlled in each cleaning process.

Landscapes

• Manufacturing Of Magnetic Record Carriers (AREA)
• Optical Head (AREA)
• Magnetic Record Carriers (AREA)
• Supporting Of Heads In Record-Carrier Devices (AREA)

Priority Applications (1)

Applications Claiming Priority (4)

Publications (2)

Family

ID=25876975

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (2)

Family Cites Families (8)

• 1989
  • 1989-01-20 DE DE3901666A patent/DE3901666A1/de active Granted
  • 1989-11-23 KR KR1019900701608A patent/KR940009724B1/ko not_active Expired - Lifetime
  • 1989-11-23 JP JP2500539A patent/JPH03503583A/ja active Pending
  • 1989-11-23 WO PCT/EP1989/001421 patent/WO1990006572A2/de unknown

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