Dynamic magnetic information storage or retrieval – Automatic control of a recorder mechanism
Reexamination Certificate
1998-11-13
2001-10-02
Sniezek, Andrew L. (Department: 2651)
Dynamic magnetic information storage or retrieval
Automatic control of a recorder mechanism
C360S060000
Reexamination Certificate
active
06297924
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates in general to a system for identifying an object using a source of irradiance and at least two detectors of light. More particularly, the present invention relates to a data storage drive for receiving a removable data storage cartridge. Even more particularly, the present invention relates to detecting the presence of, and/or identifying the type of, a disk cartridge that has been inserted in the drive using signal comparison of the light transmitted or reflected from the disk cartridge.
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 a retroreflective marker in which the reflection of a highly concentrated quasi circular lobe of light 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 the retroreflective marker is on the cartridge. The desired light lobe size is provided by the geometric size of the retroreflective elements within the retroreflective marker relative to the spacing of the emitter and the detector in the drive. The retroreflective marker reflects light in a retroreflective manner. The detector in the drive receives the light reflected from the marker, and the drive detects the presence of the cartridge responsive to the received light. This patent is incorporated herein by reference.
“LATENT ILLUMINANCE DISCRIMINATION MARKER SYSTEM FOR DATA STORAGE CARTRIDGES”, Ser. No. 08/936,970, filed Sep. 26, 1997, to Thomas, III, et al., now U.S, Pat. No. 6,091,563 describes a latent illuminance marker, such as a phosphor tag, that is attached to a data storage cartridge. After being illuminated, the marker emits latent illuminance that is detected by a photodetector. The decay time or spectral characteristic of the emitted illuminance is measured and is used to identify the data storage cartridge. The latent illuminance marker emits and reflects light in a nondirectional or spherical manner. This patent is incorporated herein by reference.
The ability to discriminate between cartridge types, such as those containing a retroreflective marker and those containing a latent illuminance marker, 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 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. 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.
Although the art of data storage cartridges and disk drives is well developed, there remain some problems inherent in this technology, particularly distinguishing between different types or generations of cartridges. Therefore, a need exists for a system that produces reliable detection and discrimination between data storage cartridges.
SUMMARY OF THE INVENTION
The present invention is directed to a system for identifying a type of data storage cartridge having a marker, comprising: a light source for emitting light to illuminate the marker; a first photodetector for measuring a first intensity of light received from the marker; a second photodetector for measuring a second intensity of light received from the marker; and a microprocessor for determining the type of data storage cartridge responsive to the first intensity and the second intensity.
According to one aspect of the present invention, the system further comprises a comparator for comparing the first intensity and the second intensity to produce a comparison result and the microprocessor determines the type of data storage cartridge responsive to the comparison result.
In accordance with an aspect of the present invention, the light source is disposed approximately directly beneath an edge of the marker, the first photodetector is disposed approximately directly beneath the center of the marker, and the second photodetector is disposed adjacent to the light source.
In accordance with a further aspect of the present invention, when the first intensity is not less than the second intensity it is determined that the marker on the data storage cartridge is transmitting light in a nondirectional manner, and when the first intensity is less than the second intensity it is determined that the marker on the data storage cartridge is transmitting light in a directional manner.
In accordance with a further aspect of the present invention, the light source is a light emitting diode (LED) and each photodetector is a phototransistor or a photodiode.
In a further embodiment within the scope of the present invention, a data storage drive is provided that comprises: a light source; a first photodetector; a second photodetector; and a microprocessor. The data storage drive is adapted to receive a cartridge comprising: a body; a data storage medium on the body; and a marker on the body. The marker is a material which receives irradiance from the light source and transmits irradiance one of nondirectionally and directionally toward the first and second photodetectors for detection. The microprocessor determines a type of cartridge responsive to an output of the first photodetector and an output of the second photodetector.
Another embodiment within the scope of this invention includes the combination of a data storage drive and a cartridge for the drive. The drive comprises: a light source; a first photodetector; a second photodetector; and a microprocessor. The cartridge comprises: a body; a data storage medium on the body; and a marker on the body. The marker is a material which receives irradiance from the light source and transmits irradiance nondirectionally or directionally toward the first and second photodetectors for detection. The micro
Graves Todd L.
Shelton Todd R.
Smith Paul
Thomas, III Fred C.
Iomega Corporation
Sniezek Andrew L.
Woodcock Washburn Kurtz Mackiewicz & Norris LLP
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