Electrical generator or motor structure – Dynamoelectric – Linear
Reexamination Certificate
1997-11-13
2001-03-27
Tamai, Karl (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Linear
C318S135000, C318S116000, C060S528000
Reexamination Certificate
active
06208044
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates generally to computer peripherals, and more particularly to digital mass storage devices having removable storage media.
Computer systems and other digital processing systems often include digital memory “peripherals” used for the mass storage of data, Examples of such digital memory peripherals include hard disk drives, floppy disk drives, optical disk drives, and Personal Computer Memory Card International Association (PCMCIA) cards or devices (also referred to as PC Cards) or other types “flash” memory cards. With some of these peripherals, the storage medium is permanently housed within and forms a part of the peripheral. An example of digital storage peripheral which does not allow the removal of its storage medium is a standard Winchester-type hard disk drive. Other memory peripherals allow the removal and replacement of the digital media. Examples of such peripherals include floppy disk drives and PCMCIA peripheral units.
For most types of storage peripherals with removable media, the media is manually inserted into a slot against spring pressure until a latching mechanism is engaged. In many types of such peripheral units, the media is disengaged from the unit by manually depressing a release button or lever to release the latch and thereby allow the compressed spring to partially eject the storage medium. A protruding end of the medium is then removed from the peripheral unit by hand.
In some computer systems, notably the Macintosh® computer system made by Apple Computer, Inc. of Cupertino, Calif., removable storage media can be automatically ejected by the computer system. More particularly, the Macintosh operating system can cause motors or electrical solenoids of the floppy drive unit to automatically eject a floppy disk.
Such automatic ejection of storage media has several advantages. For one, the computer can prevent the ejection of a floppy disk from the floppy disk drive if the system still needs or is processing data in conjunction with the floppy disk drive. Another advantage is that the floppy disk can be ejected automatically under certain conditions, such as during a power-down or power-up of the computer system. However, such automatic ejection systems have the disadvantage of increasing the cost of the floppy disk drive in that motors or solenoids must be provided, along with their attendant control circuitry.
An increasingly popular form of removable media is the PCMCIA memory card, which is typically a form of “flash” memory. As is well known to those skilled in the art, flash memory is form of non-volatile, solid-state, read-write memory, and PCMCIA cards are flash memory which conform to certain industry standards. Since PCMCIA cards are, themselves, quite small, and since they do not require drive motors or the like (as the case with disk drives) the PCMCIA peripheral unit can be made quite small and lightweight. This makes PCMCIA peripheral units quite attractive for small computers, such as laptop computers, Personal Digital Assistants (PDAs) such at the Newton® PDA, and other small, portable devices utilizing digital processors.
PCMCIA cards can be of other types than the aforementioned flash memory type. For example, there are PCMCIA cards which employ Static Random Access Memory (SRAM) and PCMCIA cards that are miniature hard disk drives. In addition, PCMCIA cards can include modem, cellular pager, and networking capabilities. The PCMCIA format is therefore quite flexible and is rapidly growing in popularity.
For a variety of reasons, in the past, PCMCIA peripheral units only permitted the manual ejection of the PCMCIA cards . For one, the addition of motors or solenoids to eject the PCMCIA card would substantially increase the size of the PCMCIA peripheral unit, which is considered very undesirable. For another, the motor or solenoid would add a significant cost to the PCMCIA peripheral unit.
SUMMARY OF THE INVENTION
The present invention includes a system and method for the automatic ejection of media. More particularly, the present invention includes a system and method for the automatic ejection of PCMCIA cards from PCMCIA peripheral units. This is accomplished using an electrically-controlled “memory wire” to eject a PCMCIA card without the use of motors or solenoids.
A memory wire control system in accordance with the present invention includes elongated memory wire and a pulse width modulator for controlling the electric current flowing through the wire. The electric current heats the wire, causing a dimensional change in the wire that can be used, for example, to release a catch on a PCMCIA peripheral unit to eject a PCMCIA card. The memory wire is preferably a bimetallic alloy comprising nickel and titanium, commonly known by the generic tradename Nitinol. The pulse width modulator is preferably computer controlled so that dimensional changes in the memory wire can be under software control.
A media ejection system of the present invention includes a peripheral unit having a housing receptive to removable medium, an ejection mechanism for ejecting the medium, and a memory wire coupled to the ejection mechanism. The system also includes a digital processor operative to issue a ejection command, and a controller responsive to the ejection command for controlling current flow in the memory wire of the peripheral unit. When the ejection command is received, current flows through the memory wire, causing it to contract, and thereby activating the ejection mechanism of the peripheral unit.
A method for ejecting a removable medium in accordance with the present invention includes the steps of: a) receiving a ejection request; b) issuing a ejection command in response to the ejection request, where the ejection command includes control parameters for a current that is to flow through a memory alloy; and c) passing an electrical current through the memory alloy in accordance with the control parameters so that the memory alloy undergoes a dimensional change to activate a removable medium ejection mechanism. Preferably, the method is computer implemented, and the step of energizing the memory alloy includes applying a pulse width modulated signal to the metal alloy in accordance with the parameters. Also preferably, the parameters included at least one of a duty cycle and a frequency for the pulse width modulated signal.
Since a memory wire or other memory or bimetallic alloy is used to activate the ejection mechanism of the peripheral, the need for motors, solenoids, or other electromagnetic actuators has been eliminated. This greatly reduces the cost of a peripheral unit having an automatic ejection mechanism. Furthermore, the memory wire does not increase the size of the peripheral unit, which is very desirable in view of the increasing miniaturization of computer systems.
These and other advantages of the present invention will become apparent to those skilled in the art upon a reading of the following descriptions of the invention and a study of the several figures of the drawing.
REFERENCES:
patent: 4654818 (1987-03-01), Wetterau, Jr.
patent: 4700541 (1987-10-01), Gabriel et al.
patent: 4742478 (1988-05-01), Nigro, Jr. et al.
patent: 4747887 (1988-05-01), Honma
patent: 4769764 (1988-09-01), Levanon
patent: 4788658 (1988-11-01), Hanebuth
patent: 4884557 (1989-12-01), Takehana et al.
patent: 4903222 (1990-02-01), Carter et al.
patent: 4969830 (1990-11-01), Daly et al.
patent: 5008805 (1991-04-01), Fiebig et al.
patent: 5030128 (1991-07-01), Herron et al.
patent: 5032705 (1991-07-01), Barcheller et al.
patent: 5041924 (1991-08-01), Blackborow et al.
patent: 5051101 (1991-09-01), Komatsu
patent: 5107400 (1992-04-01), Kobayashi
patent: 5117378 (1992-05-01), Ho
patent: 5126954 (1992-06-01), Morita
patent: 5159533 (1992-10-01), Kuang
patent: 5165897 (1992-11-01), Johnson
patent: 5175671 (1992-12-01), Sasaki
patent: 5186646 (1993-02-01), Pederson
patent: 5192222 (1993-03-01), Krause et al.
patent: 5199888 (1993-04-01), Condra et al.
patent: 5212605 (1993-05-01), Lim et al.
patent: 5214574 (1993
Boyle Dennis
Herron Matt
Law David
Viswanadham Krishna
Apple Computer Inc.
Beyer Weaver & Thomas LLP
Tamai Karl
LandOfFree
Removable media ejection system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Removable media ejection system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Removable media ejection system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2466564