Dynamic magnetic information storage or retrieval – Record medium – In container
Reexamination Certificate
2000-04-24
2002-07-23
Hudspeth, David (Department: 2651)
Dynamic magnetic information storage or retrieval
Record medium
In container
C360S069000, C369S291100
Reexamination Certificate
active
06424492
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates in general to a frequency based cartridge detection system. Particularly, the present invention relates to a detection system for identifying a disk for use in a disk drive. More particularly, the present invention has a source of irradiance for irradiating a marker, and a detector for detecting light emitted from the marker. Even more particularly, the present invention relates to detecting the presence of the correct disk in the disk drive by determining a frequency domain response of the light emitted from the marker. The frequency domain response may be either a phase response, an amplitude response, or both.
BACKGROUND OF THE INVENTION
Disk drives for receiving removable disk cartridges, including conventional 3.5 inch floppy disk drives, must have some mechanism for detecting the insertion or presence of a disk cartridge in the drive. The actuator that carries the recording heads of the disk drive across the recording surfaces of the disk should not be allowed to move unless the presence of an appropriate disk cartridge which is non-drive damaging is detected. The removability feature requires that the disk drive have a cartridge insertion opening into which foreign objects can be inserted. If these objects physically engage the drive as a legitimate cartridge would, then the heads could be loaded onto or into the foreign object, thereby destroying the drive. Also, the spindle motor of the disk drive will be activated by a falsely detected foreign object, thereby generating particle debris. In the prior art, mechanical switches are typically employed to detect the presence of a disk cartridge within the drive. Such switches are typically positioned such that when a disk cartridge is inserted fully into the drive, the cartridge contacts the switch, thereby providing an indication that the disk cartridge is present.
“RETROREFLECTIVE MARKER FOR DATA STORAGE CARTRIDGE”, U.S. Pat. No. 5,638,228, to Thomas, III, describes the reflection of a highly concentrated quasi circular lobe of light whose spread on reflection is captured by the aperture of a phototransistor in close proximity to a light-emitting diode (LED). This emitter/detector pair is in the drive and a retroreflective array is on the cartridge. The desired light lobe size is provided by the geometric size of the retroreflector array elements relative to the spacing of the emitter and the detector in the drive. Due to this physical size matching and the fact that retroreflectors are used, this marker on the cartridge is quite insensitive to cartridge tilt and distance from the emitter/detector pair in the drive. This patent is incorporated herein by reference.
Recently, very small mini-cartridges have been developed for use in miniature disc drives. These mini-drives are incorporated into hand-held devices such as digital cameras, electronic books, global positioning systems, cellular phones and the like. “INTERCHANGEABLE CARTRIDGE DATA STORAGE SYSTEM FOR DEVICES PERFORMING DIVERSE FUNCTIONS”, Ser. No. 08/746,085, filed Nov. 6, 1996, Edwards, et al., describes such mini-cartridges, mini-drives, and hand-held devices. This application is incorporated herein by reference.
As disk storage products become smaller and smaller, the need for a cartridge marker of thinner physical size is required. In very thin disk drives where the distance between the cartridge marker and the optical sensing device is very small (e.g., 1 mm), the inherent reflective gain mechanism obtained with a retroreflector over a diffuse or specular reflector is lost. Holographic directional light control is possible, but due to the very small working distances the ability for false engagement of the drive is significantly increased with that approach.
The ability to discriminate between cartridge types after insertion into a data storage device but prior to putting the read/write heads on the recording media is of significant value and utility. Principally this utility comes from the ability to detect the difference between various capacities or generations of data storage cartridges in a downward media compatible data storage drive. This discrimination capability allows for drive/media specific adjustments to be made such as media rotation rate, data channel rates, location of Z track for initial seeking, or even mechanical adjustment in the drive like the active engagement of new crash stop locations. The ability of a disk drive to predetermine the type/generation of data storage cartridge inserted into it prior to enabling the spin-up and engagement of read/write elements also provides the drive system designer with new possibilities for cross-platform interchangeability.
A “caddy” cartridge, as mentioned in the aforementioned Edwards, et al. application, provides cross drive platform compatibility, for example between mini-cartridges and personal computer cartridges. The ability to recognize the installation of a “caddy” into the drive prior to spinning up of the “caddy” and loading of heads is necessary. Again rotational speed adjustments, Z track location information, data channel rate and crash stop/ID and OD data track location information must be determined prior to read/write head loading. This invention provides a solution of these problems also.
Another problem associated with the detection of LED light reflected from any reflective material is the occurrence of illuminance hot spots or structure in the LED output which often results in uneven illumination of the cartridge marker. Reflective cartridge markers can also become faded, scratched, or soiled. These factors combine to make the amplitude of the detected light signal highly variable.
Recently, in various industries such as the distribution industry, phosphors have been used in the control of goods by means of bar codes, and furthermore, bar codes are printed on various prepaid cards and passing cards, and these bar codes are read by optical reading apparatuses such as scanners to perform the desired actions. Moreover, various attempts have been made to apply forgery preventive means to credit cards and prepaid cards or to detect forged cards. For example, the marks such as bar codes are printed with an ink containing a phosphor by offset printing or by using an ink ribbon to form latent image marks. The latent image marks are irradiated with a semiconductor laser beam to excite the phosphor and the light emitted from the phosphor is received to read the bar code information by an optical reading apparatus. These techniques use the content or spectral shift from the irradiating light source for identification.
More recently, phosphors have been used in the disk drive industry for the identification and discrimination of disk and disk cartridges in disk data storage drives. “LATENT ILLUMINANCE DISCRIMINATION MARKER FOR DATA STORAGE CARTRIDGES”, Ser. No. 09/161,007, filed Sep. 25, 1998, Thomas III, et al., describes a system for identifying and discriminating removable data storage cartridges and a data storage drive for receiving the cartridge. In addition, “LATENT IRRADIANCE DISCRIMINATION METHOD AND MARKER SYSTEM FOR CARTRIDGELESS DATA STORAGE DISKS”, Ser. No. 09/160,811, filed on Sep. 25, 1998, Krieger et al., describes a phosphor marker for discriminating a cartridgeless type disk object that has been inserted into a disk drive. The systems of each of the above relate to the detection of the presence of the phosphor marker by measuring the time required for the radiated light from the marker to decay from one level to another level after the incident light from a light source is removed (e.g., the decay rate). Although the decay rate may provide the basis for discriminating an object that has been inserted into a disk drive, this approach provides an electronically complicated method of detecting the presence of the phosphor marker.
Although the art of detecting and discriminating between data storage cartridges is well developed, there remain some problems inherent in this technology, particularly in providing an electronica
Allgood Robert D.
Smith Paul
Thomas, III Fred C.
Hudspeth David
Iomega Corporation
Tzeng Fred F.
Woodcock & Washburn LLP
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