Cleaning Disc

This invention relates to a device for cleaning the contact-type information transducing heads used by a computer-type device for reading and writing stored information. More particularly, the invention relates to a cleaning disc used to clean the magnetic heads on a floppy disc drive.

The need for providing a device which is capable of cleaning magnetic head has long been recognized. In the case of a floppy disc system, drive heads have been cleaned through the use of a cleaning surface covered disc. The cleaning disc is inserted into the drive and as the head attempts to read the contents of the disc, it gets cleaned as it rubs against the cleaning material. Since there is no magnetic information stored on the cleaning disc for the head to find, the cleaning operation is halted as the drive head returns an error signal to the processing unit of the system. In this sort of cleaning method, the disc would tend to rub against the cleaning material in about the same position each time the disc is used for cleaning as the drive head unsuccessfully looks for its initial operating instructions on the disc.

The use of cleaning discs can be improved by typing a program into the computer terminal each time the cleaning disc is used. The program can be written to specify a position for the head to go to on the disc. This is a cumbersome way of getting the drive head to contact the cleaning material in different spots for each cleaning operation. It would be difficult to keep track of the locations on the cleaning disc which have been used. One would not know when a location has been exhausted of its cleaning effectiveness through repeated usage.

This invention is directed to a cleaning device having a cleaning surface and a recording surface, both on a single substrate. A program for directing the cleaning of a contact-type information tranducing head is stored on the recording surface. The cleaning device of the present invention is for use in cleaning the drive heads of information recording systems having program reading capabilities.

According to one embodiment of the invention, memory locations on the recording surface keep track of each cleaning operation that occurs. The memory contains information for directing the drive head to specific available areas on the cleaning surface for cleaning. After each of the cleaning areas on the cleaning surface has been used a predetermined number of times, the program indicates to a user that the cleaning device has no available cleaning areas remaining and that a new cleaning device should be employed.

Thus, it is an object of the present invention to provide a cleaning disc having a self-contained program for directing a drive head to cleaning areas on the disc. It is a further object of the invention to include a memory for indicating specific available cleaning areas to be used for each cleaning operation. A still further object of the invention is the inclusion of a means for indicating when the available cleaning areas have been exhausted.

Other objects and advantages of the invention will become apparent during the following description of the presently preferred embodiment of the invention taken in conjunction with the drawings.

FIG. 1 is a plan view of the cleaning disc of the present invention contained within its jacket;

FIG. 2 is a magnified view of the cleaning material on the cleaning disc of FIG. 1; and

FIG. 3 is a plan view of the cleaning disc of the present invention.

Turning now to the drawings, FIG. 1 shows the cleaning device of the present invention in the form of a cleaning disc enveloped by its protective jacket 30. The embodiment shown is a 5.25 inch flop diskette. The jacket 30 for the cleaning disc is the same as those used for magnetic discs. There are two write protect notches 32 on opposite edges of the jacket 30. The function of these notches 32 depends upon the particular diskette embodiment. In the 5.25 inch floppy diskette, the notches 32 allow a user to write onto the disc. The two notches 32 enable the disc to be written to on either side.

Index holes 34 are positioned on the jacket 30 to identify the format type of the disc within the jacket. Floppy discs can be hard sectored or soft sectored, single density or double density and single-sided or double-sided. The index holes identify the type of disc to the disc drive system. The embodiment shown in FIG. 1 is for a soft sectored, double-sided, double density disc. Two index holes 34 are provided so that the disc can be read from or written to on either side. The index holes 34 are also used by the disc drive for proper rotational alignment of the disc within the jacket 30. The cleaning disc 10 shown in FIG. 3 has a corresponding index hole 42 which will indicate to the disc drive when the disc has been rotated into its proper initial position. Rotation of the disc 10 within the jacket 30 is accomplished by the disc drive at the hub drive hole 36 in the same way magnetic discs are rotated. Slip sheets are located within the jacket 30 on either side of the disc 10 to allow the disc 10 to rotate more easily within its jacket 30. The drive head of the disc drive makes contact with the disc within the drive head access slot 38.

The cleaning disc 10 of the present invention is shown in FIG. 3. The disc 10 is made of a disc-shaped substrate, preferably Mylar. To provide a means for storing a program on the disc, a recording surface is located over a portion of the disc. The recording surface is a magnetic oxide layer 40 which is applied to the Mylar substrate. To provide the cleaning function, a layer of cleaning material 20 must be adhered to another portion of the substrate. In the preferred embodiment, there are two rings of magnetic oxide layer 40 surrounding a ring of cleaning material 20.

The 5.25 inch double-density disc is divided into forty tracks for identifying locations to the computer system. Each track is a concentric ring about the disc. The outer ring of magnetic oxide 40 includes the first ten tracks. The innermost track in this ring of magnetic oxide 40, track nine, is left unused to guard against any problems which may be caused by inaccuracies in the placement of the cleaning material 20 on the disc 10. The next twenty-one tracks are covered by the cleaning material 20. The inner and outer two tracks in the cleaning portion are not used in the program of the preferred embodiment to allow a tolerance for inaccurate cleaning material placement. The remaining inside nine tracks are in the other portion of the magnetic recording surface 40. The outermost track in this portion is not used. On the opposite side of the disc from that shown in FIG. 3, all of the tracks are covered by a magnetic oxide layer. This opposite side has a function only when the cleaning disc is being used in a double-sided disc drive.

Any number of cleaning materials may be used for cleaning layer 20. The preferred cleaning material is disclosed in U.S. Pat. No. 4,408,241, having the same assignee as the present application. The disclosure of U.S. Pat. No. 4,408,241, is incorporated by reference herein. This cleaning material is illustrated in FIG. 2. A layer of adhesive 22 is applied to the Mylar substrate. The presently preferred adhesive is an acrylic with a toluene solvent. Elongated strands 24 of plastic form a web of fabric which is bonded to the adhesive. The presently preferred strands 24 are made of polyester. The strands 24 acts as ridges which knock material off the drive head when the head is rubbed against the cleaning material 20. Material which is removed from the drive head adheres to the adhesive 22. The adhesive is exposed on the substrate between the strands 24. The adhesive 22 controls the removed particles by substantially preventing them from depositing on other portions of the disc drive system. One alternative cleaning material 20 which could be substituted for the illustrated web of fabric is a soft non-abrasive lint-free cleaning surface. The soft fabric would be bonded to the substrate. To improve the cleaning properties of the soft fabric, a drop of non-flammable water based cleaning fluid should be applied to the fabric before each cleaning use.

The magnetic oxide layer 40 contains the program for directing the use of the cleaning disc 10. The program should include either the disc operating system program for the disc drive system to be cleaned or a program which will enable a user to copy the disc operating system program onto the cleaning disc 10. Once the operating system is on the disc 10, a user may access the cleaning program stored on the magnetic oxide layer 40. Preferably, the cleaning program is made to be "user friendly". This means that understandable and frequent messages are provided to the user so that a minimum amount of instruction would be required to teach a person to use the cleaning disc.

The cleaning program of the preferred embodiment accesses a memory location which stores a counter. The counter keeps a record of the number of uses of the cleaning disc. When the cleaning program is executed, the program increments the counter by one. A table is stored in the memory on the disc which provides a corresponding cleaning track location for each value of the counter. Each time the cleaning program is called, a specific available cleaning area is identified by accessing the table with the counter's value.

The outer tracks have a greater circumference and thus a greater cleaning area than the inner tracks. Therefore, the outer tracks can be used more times. The preferred embodiment provides for fifty uses of the cleaning disc. Once a cleaning area from the cleaning material 20 portion of the disc has been used a predetermined number of times, it will no longer be available for cleaning. It could be detrimental to a drive head to rub it against cleaning material which has been soiled by repeated cleaning operations. In the presently preferred embodiment, tracks twelve to seventeen are used four times each, tracks eighteen to twenty-one are used three times each and tracks twenty-two to twenty-eight are used twice each.

When the program is executed, it looks at the table for the specific available cleaning area corresponding to the value of the counter. The program then instructs the drive head to write at the cleaning area thus identified. Since the drive head will be unable to write because it will find cleaning material at the location rather than magnetic oxide, in some systems an error signal will be sent back to the computer device. The program contains an instruction loop for repeating the write operation. To accommodate systems which will produce an error signal, the program contains instructions in the loop for ignoring the error signal. Each write is approximately three seconds. A separate variable keeps track of the number of iterations through the loop. A write operation will be attempted again for each iteration through the loop. In the preferred embodiment the loop is reiterated four times so that about twelve to fifteen seconds of cleaning time over the cleaning material is achieved. Once the cleaning operation has been completed, a message will be printed for the user indicating that the cleaning has been finished. Then, control is returned to the operating system program.

When a double-sided disc drive is being cleaned by the cleaning disc 10, the interaction between the program and the drive system requires that file information be stored in the tracks corresponding to the cleaning material on the opposite side of the disc 10. This allows the system to respond properly to the instructions directing the disc drive to write in the cleaning material tracks. After one side of a double-sided disc drive is cleaned, the cleaning disc may be removed and flipped over so that the other disc drive head may be cleaned. When the soft fabric cleaning material is being used, a drop of cleaning fluid should be applied to the fabric before cleaning the other head.

When the cleaning disc has been used the predetermined maximum number of times, it should be discarded. When the counter in the program indicates that the disc has been used the maximum number of times, it will send a message to the user indicating that the cleaning disc has been completely used and should be discarded. The program will not allow further cleaning uses with that cleaning disc since there are no available cleaning areas remaining. This advantageously provides a disc which monitors itself so that a dirty disc is never used for cleaning a disc drive head. Optimal results are thus obtained by cleaning a drive head only with available cleaning areas, those which have not been soiled by excessive prior uses.

A listing of the presently preferred program for a cleaning disc having the cleaning material illustrated in FIG. 2, and being used on an IBM PC/DOS or MS/DOS Disc Operating System follows: ##SPC1##

Of course, it should be understood that various changes and modifications to the preferred embodiments described above will be apparent to those skilled in the art. For example, the substrate may be made of polyester of any number of other materials. The configuration of the cleaning material and the magnetic oxide layers of the cleaning disc may be rearranged. The program might be written to direct the drive head to a randomly selected cleaning area for each use. It may also be possible to use the combination of a cleaning area and programming area on one substrate in other information recording systems. These and other changes can be made without departing from the spirit and the scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be covered by the following claims.