US20210157515A1 - Cartridge-external preamplifier for read/write control of media library - Google Patents

Abstract

A storage system includes a media player including a preamplifier that is adapted to provide data access to a storage cartridge lacking an independent read/write preamplifier. The media player couples to the storage cartridges across an interconnect, and the storage cartridge is adapted perform data access operations responsive to signals received from the media player through the interconnect.

Description

SUMMARY
• A storage system includes a media player that couples to a storage cartridge across an interconnect. The media player includes a preamplifier that inputs and outputs electrical signals across the interconnect. The storage cartridge lacks an independent read/write preamplifier but is controlled via the interconnect to perform data storage operations.
• This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other features, details, utilities, and advantages of the claimed subject matter will be apparent from the following more particular written Detailed Description of various implementations and implementations as further illustrated in the accompanying drawings and defined in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 illustrates an example disk-based storage system in which a preamplifier has been displaced from a traditional position (e.g., internal to a storage cartridge or within the head disk assembly of a hard disk drive) to a position external to the storage cartridge that is within a media player.
• FIG. 2 illustrates another example storage system with a disk-based storage cartridge that does not include an internal read/write preamplifier.
• FIG. 3 illustrates still another example storage system including disk-based storage cartridges that do not include internal read/write preamplifiers.
• FIG. 4 illustrates still another example storage system including disk-based cartridges that do not include an internal read/write preamplifiers.
• FIG. 5 illustrates aspects of still another example storage system including disk-based cartridges that do not include an internal read/write preamplifiers.
• FIG. 6 illustrates another example cartridge-based storage system including storage cartridges that do not include internal read/write preamplifiers.
• FIG. 7A illustrates a top view of an example storage cartridge that may be used to implement the herein disclosed technology.
• FIG. 7B illustrate a bottom view of the example storage cartridge ofFIG. 7A.
DETAILED DESCRIPTION
• The growing use of cloud-based storage solutions has driven demand for low-cost data storage systems capable of retaining large volumes of data. However, as the amount of stored data continues to increase exponentially, so too does the difficulty in ensuring access to data at speeds acceptable to both service providers and end users. In light of this, storage centers (e.g., cloud-based storage providers) drive demand for storage devices with high storage density, high throughput, and low cost. In most designs, these throughput and cost are mutually exclusive and increasing throughput (e.g., the amount of data read or written in a set amount of time) cannot be achieved without also increasing storage device manufacturing costs.
• In some archival storage systems, data is stored in enclosures (referred to herein as “storage cartridges”) that include one or more physical storage media (e.g., disks or SSDs). These cartridges lack at least some of the read/write control circuitry and mechanics that is included in a more traditional stand-alone storage device (e.g., an external hard drive). In some of these systems, the cartridges are designed to be physically mated with a media player that includes power circuitry and read/write control circuitry. For example, the cartridges may be capable of physically coupling to and decoupling from a media player such that a single set of control electronics in the media player can be used to read multiple (e.g., hundreds or thousands) of different cartridges.
• In these cartridge-based archival systems, the exact division of control electronics between the cartridge and media player may vary form one implementation to another. However, in one implementation, the media player includes circuitry that receives and generates read and write signals along with instructions that may be interpreted by a preamplifier to control ancillary signals and switches/multiplexers required to connect the read and write signals to the desired recording head. These generated read signals, write signals, and instructions are sent via an electrical interface through a connection port to a select storage cartridge to a preamplifier internal to the select storage cartridge. The preamplifier may, for example, include various amplifiers, driver circuits, and/or switches and/or multiplexers for coupling read/write component signals along corresponding traces to respective subcomponents on one or more read/write heads. For example, the preamplifier may receive a command to select a particular recording head or to activate a circuit to the desired head in response to the command. Additionally, the preamplifier may also be commanded to control ancillary circuitry required for data storage. For example, the preamplifier may generate a current to one or more heater elements of the selected recording head to thermally expand target head regions and thereby provide fine control of head-to-disk spacing; signal(s) to control micro actuators to provide fine radial motion control of the head, and bias currents for the reader elements.
• In the above-described systems, the preamplifier internal to the storage cartridge contributes significantly to the manufacturing cost of each storage cartridge. In some cases, the preamplifier cost may be as much as 10% or more of the total manufacturing costs of the storage cartridge. Thus, the ability to remove the preamplifier from the storage cartridge and place it in the media player could have a dramatic cost-reducing impact on a massive library-style cartridge storage system (e.g., by replacing potentially thousands of cartridge-internal preamplifiers with a single preamplifier in the media player that may be shared by all storage cartridges).
• Despite this evident potential cost savings, it has been previously thought by many industry experts that, for several reasons, it is functionally essential for the preamplifier to remain within the storage cartridge where it is in close proximity to the head gimbal assembly (HGA) that supports the read and write elements. The read and write signals are generated in preamplifier at very high frequencies (e.g. GHz range). Moving the preamplifier out of the storage cartridge has the effect of dramatically increasing (e.g., by a factor of 3 or more) the travel distance read/write signals traverse between the HGA and the preamp. Using traditional techniques, the high-frequency read/write signals are degraded along this longer path due to high-frequency signal attenuation and an increase in coupled noise correlated with path length.
• In addition to presenting new obstacles in noise mitigation, displacing the preamplifier from the storage cartridge decreases the rise time for each current pulse that is sent to the HGA. It is generally believed that accurate writing (e.g., accurately targeting bits to transition in magnetic polarity) depends, at least in part, on the ability to generate a write current with pulses that have sufficiently high (fast) rise times. Therefore, moving the preamplifier external to the storage cartridge further entails derivation of a solution that either keeps rise time high or that compensates for a loss in rise time. Still further, another reason to keep the preamplifier internal to the storage cartridge is to protect the HGA from electrostatic discharge (ESD) events (shocks) that may damage the especially fragile read/write elements.
• The herein disclosed technology provides a cartridge-based storage solution that addresses all of the forgoing and thereby facilitates displacement of the preamplifier from a position internal to the storage cartridge to a position external to the storage cartridge. This dramatically reduces systems manufacturing costs without a corresponding reduction in read and write throughput.
• FIG. 1 illustrates an example disk-basedstorage system100 in which a preamplifier has been displaced from a traditional position (e.g., internal to a storage cartridge102) to a position external to thestorage cartridge102 that is within amedia player104. Themedia player104 couples with thestorage cartridge102 to read data from and write data to astorage media108.
• By example and without limitation, theexemplary storage cartridge102 is a portable storage cartridge that resembles a conventional hard drive disk (HDD), but without certain mechanical and electrical features that would otherwise be necessary to enable the cartridge to operate in a stand-alone fashion. The various storage cartridges discussed herein may, for example, generally assume the form of an HDD minus control electronics and, in some cases, other elements that can be offloaded from the cartridge and supplied by the actuated media player, such as VCM magnets and spindle motor components. The removal of these elements from the individual cartridges in the library allows the provisioning of a large-scale, high-capacity storage system with the benefits of magnetic disc storage at a significantly lower cost.
• Although a media player adapted to access thestorage cartridge102 may include different components in different implementations, themedia player104 is shown to include a read/writecontroller110, apower circuit114, volatile memory132 (e.g., DRAM), non-volatile memory106 (e.g., Flash), and apreamplifier112. In one implementation, the read/write controller110 includes a programmable processing core that utilizes firmware stored in thenon-volatile memory106 andvolatile memory132 to provide top-level control for thestorage cartridge102. In various implementations, the read/write controller110 may include software or a combination of software and hardware, such as control instructions executed by one or more separate or shared device controllers (e.g., microprocessors), peripheral interface controllers (“PICs”), application-specific integrated circuits (“ASICs”), systems on chips (“SoCs”), etc.
• In one implementation, the read/write controller110 includes an SOC that communicates with an external controller to a host, such as a computer, a server, a rack controller, a storage array switch, etc. through ahost connection interface116. Communication between the host (not shown) and themedia player104 are digital or primarily digital, and accomplished via signal transmission between various compute nodes achieved via wired or wireless transmission protocols including, without limitation, one or more Serial Advanced Technology Attachment (“SATA”), Serial Attached Small Computer System Interface (“SAS”), Universal Serial Bus (“USB”), Peripheral Component Interconnect Express (“PCle”), Non-Volatile Memory Express (“NVMe”), Ethernet, Kinetic, object storage protocols, wireless protocols, etc. Alternately, the device may contain internal support for full file-system or object-storage access entirely within itself, and may communicate files or objects (instead of blocks) to the host viahost connection interface116. In one implementation, themedia player102 has a hard-wired connection (e.g., cable) facilitating communications with the host, such as a rack-level controller (not shown). In another implementation, themedia player104 includes a transceiver and an antenna configured to wirelessly receive and respond to host commands over a local area network (LAN) or a wide area network (WAN).
• In various different systems, the coupling between themedia player104 and thestorage cartridge102 may be permanent or temporary (e.g., designed for selective coupling and decoupling during normal use operations). In one implementation, themedia player104 is adapted to selectively couple with and uncouple from thestorage cartridge102. For example, themedia player104 may be designed to move (e.g., by way of robotically-actuation along rails or otherwise) relative to multiple storage cartridges in a library so as to selectively position itself for mating with select storage cartridge(s) through aconnection interface118. In another implementation, themedia player104 is designed to remain stationary within thestorage system100 while the storage cartridges (e.g., the storage cartridge102) are moved into position for selective coupling to and decoupling from themedia player104. For example, thestorage system100 may include a robotic arm or other mechanism that attaches to and selectively ambulates individual storage cartridges from stowed storage positions on a rack and toward themedia player104 to facilitate a physical and electrical coupling between themedia player104 and storage cartridges. The media player may, for example, include a slot or other access station designed to receive and temporarily support the storage cartridge during a time while themedia108 is being accessed.
• In still yet another implementation, themedia player104 andstorage cartridge102 are designed to remain in fixed positions relative to one another within the storage system. For example, theconnection interface118 may facilitate simultaneous electrical coupling to multiple different storage cartridges that share control electronics on themedia player104 and that may each be selectively and individually powered and accessed by themedia player104.
• In one implementation, themedia player104 is designed to selectively couple with and provide data access to a single one of the storage cartridges at a time. In other implementations, themedia player104 is adapted to simultaneously couple to multiple storage cartridges at once (e.g., two or three adjacent cartridges) and to provide parallel data access operations to two or more of those storage cartridges.
• Thestorage cartridge102 includes a housing which encloses at least one rotatable recording medium (disk), such as a magnetic hard disk or a Heat-Assisted Magnetic Recording disk (HAMR), and at least one data read/write transducer (head), also referred to herein as a head-gimbal assembly (HGA). InFIG. 1, thestorage cartridge102 is shown to include a single disk; however, it is understood that thestorage cartridge102 may include multiple discs and multiple actuator arms and/or actuator assemblies. In some implementations, themedia player104 is designed to access data from other types of storage devices that are not disk-based, such as SSD media devices, tapes etc.
• In some implementations, thestorage cartridge102 includes a sealed outer housing and each head is configured to be aerodynamically supported adjacent a magnetic recording surface of the corresponding disc by an air-fluid bearing established by high velocity rotation of the disc. The head(s) are radially advanced across the recording surface(s) using anactuator assembly120 to rotate anactuator arm122 that, in turn, supports a head gimbal assembly (HGA)124 including one or more read elements and one or more write elements.
• Each combination of HGA and disc surface is referred to as a head-disc interface (HDI), so the cartridges of the present disclosure can be characterized as HDI cartridges each having at least one HDI. The housing of each cartridge protects the HDI(s) from contaminants that may interfere with the operation of the cartridge. In some implementations where environmental controls are sufficiently in place to guard against contaminants, the cartridge may comprise housing such that the internal discs of one cartridge are exposed to the same environment as the internal discs of other cartridges in the system.
• During read and write operations, themedia108 is selectively controlled by a spindle motor signal from thepower circuit114 to rotate about aspindle axis130 while theactuator assembly120 is selectively controlled by a voice coil motor (VCM) signal to physically actuate theactuator arm122 about apivot axis126 and thereby move theHGA124 radially across themedia108. Within thestorage cartridge102, signals in transit between thepreamplifier112 and theHGA124 travel along a flexible electrical component referred to herein as aflex128. Theflex128 includes a number of electrical traces along which control signals, read data, and write data may flow.
• In one implementation where themedia player104 and thestorage cartridge102 are designed to selectively couple and decouple from one another, the read/write controller110 instructs thepower circuit114 to provide power to thestorage cartridge102 responsive to detection of a coupling between themedia player104 and thestorage cartridge102. In response, thepower circuit114 shunts power from a power supply (not shown) to provide both VCM and spindle motor power signals, as shown.
• In addition to commanding thepower circuit114, the read/write controller110 may access firmware stored in thenon-volatile memory106 to retrieve operating protocols for thestorage cartridge102. In some implementations, these operating protocols may be received via transmission from a system host or other external processing device.
• To read data from a target storage cartridge, the read/write controller110 generates and transmits instructions, such as a head selection message, to thepreamplifier112. Thepreamplifier112, in turn, selects via internal switches and/or multiplexers signals attached to reader elements of a select HGA (e.g., the HGA124) to select and configure a read channel for transmitting read data back to the read/write controller110.
• Responsive to receipt of a corresponding instruction (e.g., a low-speed digital signal) from the read/write controller110, thepreamplifier112 generates a small bias current, and the bias current is transmitted along a pair of reader lines down the length of theflex128 to the HGA124 A magnetoresistive (MR) sensor on theHGA124 modulates this bias current at high frequencies (e.g., GHz range), and the modulated voltage travels back along the length of theflex128 to thepreamplifier112 over the same reader lines. Thepreamplifier112 amplifies the weak, modulated signal and transmits the signal back to the read/write controller110 through theconnection interface118.
• During a write operation, the read/write controller110 sends a high-speed digital preamp control signal that instructs thepreamplifier112 to control the polarity of analog current flow through a write element of theHGA124. In response, thepreamplifier112 generates and directs a high-frequency analog write signal through a transimpedance amplifier. This amplified analog write signal is routed down the length of theactuator arm122 on theflex128 to a write element on theHGA124, where it effects the switching of current flow direction through a writer coil in the write element.
• In addition to generating the high-frequency analog read and write signals and routing such signals to a select HGA (e.g., the HGA124), thepreamplifier112 may also generates and/or senses various lower-bandwidth signals, such as signals for controlling one or more heaters on the select head, one or more micro actuators, etc.
• Thepreamplifier112 can be located within themedia player104 due to one or more adaptations to thestorage cartridge102 that are discussed with respect to the following figures. In one implementation, theflex128 includes a number of traces that are impedance-matched to corresponding read and write elements on theHGA124. This preserves signal quality by preventing signal reflection off theHGA124. In the same or another implementation, thestorage cartridge102 includes an electrostatic discharge (ESD) protection mechanism (e.g., a switch or electrical shunt) that shields theHGA124 from electrostatic shocks traditionally absorbed by an in-cartridge preamplifier. In still yet another implementation, the read/write controller110 is tuned to adjust outgoing write signals in such a way that write errors do not increase as a result of the increased distance between thepreamplifier112 and theHGA124. Further exemplary details of the above are discussed further with respect toFIG. 2-6 below.
• FIG. 2 illustrates anotherexample storage system200 with a disk-basedstorage cartridge202 that does not include an internal read/write preamplifier. As used herein, the term “read/write preamplifier” is used to refer to a preamplifier that is adapted to perform amplification of both read signals and write signals.
• Thestorage system200 includes amedia player204 that supports control circuitry for reading data from and writing data from the disk-basedstorage cartridge202. By example and without limitation, the media player is shown to be a printed circuit board assembly (PCBA) including several circuitry components the same or similar to those described with respect to themedia player104 ofFIG. 1, such as a read/write controller210,preamplifier212,power circuit214,non-volatile memory206, andvolatile memory208. Some implementations of themedia player204 may include fewer than all components or other components in lieu of or in addition to those shown inFIG. 2.
• Themedia player204 is designed to mate with thestorage cartridge202 through an interface formed byconnection components218 and220. The read/write controller210 on themedia player204 generates and transmits one or more preamp control signals to thepreamplifier212. Within thepreamplifier212, the preamp control signals are interpreted to configure various multiplexers and/or switches to establish appropriate channels to read or write data with a select HGA (e.g., the HGA224). When these multiplexors and/or switches are configured, high-frequency analog read/write signals may travel between theHGA224 and themedia player204 through the matedconnection components218,220 and along aflex232 that extends within thestorage cartridge202 from theconnection port220 all the way along the actuator arm222 to anHGA224 supporting one or more write elements.
• To better illustrates features of theflex232, an alternate view234 (shown in dotted lines) illustrates theflex232 in isolation of surrounding system elements. At a first end, theflex232 includes theconnector component220 that is designed to mate with theconnector component218 of themedia player204.
• Theflex232 includes several different electrical traces that extend from theconnector component220 all the way down the length of theflex232 to corresponding components on theHGA224. In traditional storage devices, thepreamplifier212 may be located within thestorage cartridge202 and on theflex232, such as in an approximate position as indicated by theplaceholder box238. In these more traditional designs, analog write signals are generated and amplified in close proximity to the select write element. Likewise, weak read signals are amplified in close proximity to the select read element. Thus, the distance that the weak (pre-amplified) read and write signals have to travel is relatively short compared to the presently-illustrated design where thepreamplifier212 is located on themedia player204 external to thestorage cartridge202.
• By example and without limitation,view234 illustrates example uses for each of multiple different traces on theflex232. Here, the example traces include agrounding trace242, heater signal trace(s)244, micro actuator signal traces246, a pair of read signal traces248, and a pair or write signal traces250. In heat-assisted magnetic recording ((HAMR) devices, an additional trace may be devoted to drive a laser diode that generates a laser beam to heat a media. In general, thegrounding trace242 is used to ground certain components ofHGA224. The read signal traces248 are used to transmit a bias current from thepreamplifier212 to the read sensor on theHGA224 and to transmit a high-frequency reader sensor signal from theHGA224 to thepreamplifier212. The write signal traces250 are used to send current to the writer element of theHGA224 to magnetize the media (not shown). Heater traces244 are used to carry electrical currents to heaters that may thermally protrude targeted areas on theHGA224 to provide fine control of the fly height for the read and write elements. Microactuator traces246 are used to carry microactuation voltages to corresponding microactuators on theHGA224 to provide fine motion control (tracking) of theHGA224. Different implementations may include different numbers of traces in addition to or in lieu of those shown. In one implementation, theflex232 includes 13 different traces to carry signals to theHGA224. Thus, it is to be appreciated that proposed design passes a large number of relatively weak analog component signals through theconnection components218 and220 where previous designs used these ports for transmission/reception of a much stronger amplified signals.
• To mitigate or prevent noise degradation that might otherwise obliterate or substantially degrade the relatively weak read and write signals passing through theinterconnect218/220, the read signal traces248 are designed to provide an impedance-matched read path252 that matches the internal impedance of a corresponding read element on theHGA224. Likewise, the write signal traces250 are designed to provide an impedance-matchedwrite path254 that matches the internal impedance of a corresponding write element on the HGA226. This impedance matching effectively prevents reflection of the read and write component signals along the associated traces (248 and250) that could otherwise interfere with those signals.
• In the system ofFIG. 2, the amplification of and write signals is performed by thepreamplifier212 within themedia player204 rather than within thecartridge202. In one implementation, thepreamplifier212 receives digital signal from the read/write controller210 that the preamplifier interprets to control the polarity of analog current transmitted to the magnetic write pole of the HGA. Thepreamplifier212 may use switches/multiplexers to select between a plurality of writer circuits, and to send the write current to the selected write element.
• The analog write current travels from thepreamplifier212, through theinterconnect218/220, and along an impedance-matchedwrite path254 to the HGA. In one implementation, the impedance-matchedwrite path254 includes an impedance-controlled differential pair of lines.
• On a read operation, thepreamplifier212 supplies a bias current to the desired reader element (selected via an internal switch) and this current is transmitted down an impedance-matched read path252, which includes an impedance-controlled differential pair of lines, to an MR sensor on the HGA. Thepreamplifier212 receives modulated voltages back from the MR sensor on the same reader pair, amplifies this received signal, and transmits the amplified signal back to the read/write controller210.
• Although the degree of impedance matching may vary from one implementation to another, one implementation of thesystem200 provides for impedance-matching along the impedance-matched read path252 and impedance-matchedwrite path254 to within 10% of the impedance of corresponding read and write elements.
• FIG. 3 illustrates still anotherexample storage system300 including disk-based cartridges (e.g., a disk-based cartridge302) that do not include internal read/write preamplifiers. Rather, a read/write preamplifier312 is located within amedia player304 that may selectively couple with each one of the storage cartridges across aninterconnect308. In one implementation, themedia player304 is adapted to selectively couple with and decouple from the disk-basedcartridge302 via theinterconnect308. In other implementations, themedia player304 is designed to couple permanently with a subset of disk-based cartridges such that all of the cartridges are permanently attached to themedia player304 but are commonly controlled by the control electronics on themedia player304.
• Themedia player304 is shown to include at least a read/write controller310, apower controller314, and apreamplifier312. Although not shown, it is to be understood that themedia player304 includes other elements such as those described with respect to the media players ofFIG. 1-2.
• Thestorage cartridge302 is a disk-based storage media that includes at least one disk (e.g., a disk216) that is accessed (read to and written from) by read/write elements on anHGA324. Control signals traveling to and from theHGA324 travel along electrical traces on aflex318. In the interest of better clarifying features of theflex318, an actuator arm is not shown inFIG. 3. However, it is to be understood that theHGA324 is mounted at the end of an actuator arm (as shown with respect toHGA124 onactuator arm122 ofFIG. 1) and that theflex318 is at least partially supported by the actuator arm (e.g., theflex318 runs along the full length of the actuator arm to the HGA324). In one implementation, theflex318 is a flexible thin electrical component (e.g., a film) with printed electrical traces for carrying signals between thepreamplifier312 and theHGA324. Other aspects of thestorage cartridge302 may be the same or similar to those described with respect toFIG. 1-2, above.
• In some traditional storage devices, thepreamplifier312 is located on theflex318 in close proximity to theHGA324, such as at an approximate position indicated by abox326. In these traditional designs, theflex318 includes significantly fewer traces upstream of the preamplifier (e.g., the box326) than that shown. For example, the preamplifier would, at the position of thebox326 receive a multiplexed signal and demultiplex the signal into several component signals. In these designs, thepreamplifier312 is in close enough proximity to theHGA324 that it may, by virtue of its size and position, effectively absorb electro-static discharge (ESD) along theflex318 and protect theHGA324 from damage due to ESD events. In the present design, however, thepreamplifier312 is displaced to theexternal media player204 and therefore cannot protect theHGA324 from ESD on theflex318.
• Electrostatic charge is most likely to be induced along the traces of theflex318 as a result of inadvertent contact between electrical leads at theinterconnect308 and objects or substances in the surrounding environment. To protect theHGA324 from damage due to electrical charge that may accumulate on theflex318, theflex318 is electrically coupled to anelectrical shunt mechanism328 that resistively grounds the electrical traces on theflex318 until a secure connection is fully established at theinterconnect308 between themedia player304 and thestorage cartridge302. By ensuring the electrical traces on theflex318 are grounded until this connection is complete, theHGA324 is protected from ESD events. Theelectrical shunt mechanism328 may include different components and assume a variety of different forms in different implementations.
• By example and without limitation, theshunt mechanism328 includes aflexible metal pin332 that attaches the traces on theflex318 to anelectrical ground334 whenever thestorage cartridge302 and themedia player304 are uncoupled from one another. When themedia player304 is selectively coupled to thestorage cartridge302 at theconnection interface308, a rigid pin330 (or other protrusion, flange, etc.) engages with theflexible metal pin332 and applies a force that pushes theflexible metal pin332 out of initial position, thereby severing its connection to theelectrical ground334. In one implementation, this connection between theground334 and the traces on theflex318 is only interrupted at a time when a secure mechanical and/or electrical connection has been established at theconnection interface308 between themedia player304 and thestorage cartridge302. [[Note: I made up this shunt design based on my understanding of the concept. If you have a more realistic image or particular design in mind I am happy to change this]].
• FIG. 4 illustrates still anotherexample storage system400 including disk-based cartridges (e.g., a disk-based cartridge402) that do not include an internal read/write preamplifiers. Rather, a read/write preamplifier412 is located within amedia player404 that is removably couplable to each of the storage cartridges across aninterconnect408. Themedia player board404 is shown to include at least a read/write controller410, apower controller414, and apreamplifier412. Although not shown, it is to be understood that themedia player404 may include other elements including those described with respect to the media players ofFIG. 1-2.
• Thestorage cartridge402 is a disk-based storage media that includes at least one disk (e.g., a disk416) that is accessed (read to and written from) via head elements on anHGA424. Control signals traveling to and from theHGA424 travel along electrical traces on aflex418. Although no actuator arm is shown inFIG. 4, it is to be understood that theHGA424 may be mounted at the end of an actuator arm (as shown with respect toHGA124 onactuator arm122 ofFIG. 1) such that theflex418 is at least partially supported by the actuator arm (e.g., theflex418 runs along the full length of the actuator arm to the HGA424). Other aspects of thestorage cartridge402 and flex not described specifically with respect toFIG. 4 may be the same or similar to those described with respect toFIG. 1-3, above.
• In thestorage system400, theflex418 is electrically coupled to anelectrical shunt mechanism428 that protects theHGA424 from ESD events. In contrast with theelectrical shunt mechanism328 described with respect toFIG. 3, theelectrical shunt mechanism428 ofFIG. 4 assumes the form of a switch that grounds the electrical traces on theflex418 until a coupling between themedia player404 and thestorage cartridge402 is secure at theconnection interface408.
• In one implementation, theelectrical shunt mechanism428 is a micro-electromechanical system (MEMS) switch. When the switch is in a closed position, the traces on theflex418 are grounded. When the MEMS switch detects an input from the media player404 (e.g., responsive to the establishment of a secure connection at the connection interface408), the MEMS switch is controllably reconfigured to assume an open switch position, un-grounding the traces on theflex418 and allowing the traces to carry received control signals from themedia player404 to theHGA424.
• In another implementation, theelectrical shunt mechanism428 assumes the form of an inexpensive preamplifier located on theflex418 in close proximity to theHGA424. For example, a primary stage preamplifier is included on the media player (e.g., the primary preamplifier is preamplifier412) and a second stage preamplifier is included on theflex418, such as in close proximity to the HGA424 (e.g., such as in the same or similar position to preamplifiers in traditional disk-based storage devices). In this design, however, the second stage preamplifier could be a very inexpensive basic preamplifier or electronic switch that still suffices to protect theHGA424 from ESD events. For example, the second stage preamplifier may act as the read preamplifier but not serve as the write preamplifier and/or may not serve to amplify other component signals in transit to and from theHGA424. In this sense, the secondary preamplifier may be a read preamplifier but not a read/write preamplifier. In another embodiment, thestorage cartridge402 may not contain any amplifiers at all, but may instead consist solely of electronic switches.
• In this design, the primary preamplifier on themedia player404 may provide more advanced functionality such as for writing data to the media or operating a laser (e.g., in heat-assisted magnetic devices). This solution therefore allows for a significant system cost savings because the primary (more expensive) preamplifier may be shared by multiple cartridges in a library-style storage system.
• FIG. 5 illustrates aspects of still anotherexample storage system500 including disk-based cartridges (e.g., a disk-based cartridge502) that do not include an internal read/write preamplifiers. Thesystem500 includes amedia player504 that is removably couplable to each of the storage cartridges across aninterconnect508. Themedia player504 includes read/write control electronics including a read/write controller510 and apreamplifier512. Although not shown, it may be understood that themedia player504 may include other circuitry and components the same or similar to those discussed with respect to other figures herein.
• During writing operations to the media within thestorage cartridge502, the read/write controller510 generates a digital signal that a preamplifier interprets to generate an analog write signal and to control polarity of the write signal. The analog write signal is amplified within the preamplifier and transmitted through theinterconnect508 and along a length of a flex518 to reach a write element on an HGA524. The write element translate the series of write current pulses into magnetic pulses of corresponding magnitude which, in turn, polarizes one or more magnetic bits on the storage media.
• The read/write controller510 includes a writecurrent parameter adjuster506 that may adjustably control different parameters of the write current pulses. To illustrate these parameters, an example writecurrent pulse526 is shown. One of these write current parameters is steady state write current amplitude (I_WRT), or the base amplitude of each write current pulse excluding anovershoot portion528 included at the beginning of the writecurrent pulse526. Another of the write current parameters is overshoot amplitude (IOS_0-pk), or a positive amplitude maximum of theovershoot portion528 of the writecurrent pulse526. Still another write current parameter is overshoot duration (PW50), which refers to the width of the overshoot portion142 at 50% of the pulse amplitude (full width at half maximum or PW50). A fourth write current parameter is rise time (tr_{10-90% OSpk}) or the time that it takes for the write current pulse140 to initially rise between 10% and 90% of the maximum value of theovershoot portion528.
• In general, rise time (tr_{10-90% OSpk}) is correlated with bit transition accuracy, and it is well known that high rise times correlate with higher write accuracy. When thepreamplifier512 is removed from thestorage cartridge502 and displaced to the illustrated position within theexternal media player504, this decreases the rise time, which may, without correction or compensation, lead to an observed increase in write errors in excess of a correctable error margin. In one implementation of thesystem500, however, the writecurrent parameter adjuster506 compensates for this decrease in rise time by increasingovershoot528 of the write current pulse.
• FIG. 6 illustrates another example cartridge-basedstorage system600 including storage cartridges (e.g., a storage cartridge602) that do not include internal read/write preamplifiers. Rather, a read/write preamplifier612 is located within amedia player604, and themedia player604 is adapted to selectively couple with and provide data access to each of the different storage cartridges. In addition to thepreamplifier612, themedia player604 is shown to include a read/write controller610, apower controller614,non-volatile memory606 andvolatile memory616. Although not shown, it is to be understood that themedia player604 may include other elements including those described with respect to the media players ofFIG. 1-2.
• InFIG. 6, the storage cartridge includes three different disks (disk1,disk2, and disk3) and actuator arms (1-6) each supporting a corresponding HGA (e.g., an HGA624) that is adapted to provide read/write access a different disk surface. A different flex element (e.g., flex elements1-6) extends along each one of the different actuator arms, routing multiple electrical traces to the corresponding HGA. For example, each flex may provide a corresponding HGA with one or more micro actuator control signal(s), heater control signal(s), a read signal, a write signal, a laser signal, ground, etc.). All of the traces extend through theinterconnect608. Thus, in an example where each flex carries13 individual traces to an associated one of six total HGAs in thestorage cartridge602, there may exist 78 total (13x6) traces that electrically couple to leads at theinterconnect608 such that all 78 electrical traces are input to thepreamplifier612. In some implementations, thestorage cartridge602 may include more than six HGAs.
• In one example implementation, each flex includes read and write paths that are impedance-matched to the impedance of corresponding read and write elements to mitigate signal reflection. In the same or another implementation, thestorage cartridge602 includes an electrical shunt mechanism (e.g., as discussed with respect toFIG. 3 or 4) to protect the HGAs from ESD. In the same or another implementation, the read/write controller610 selectively increases overshoot of outgoing write current pulses to help improve write transition accuracy to compensate for a decrease in maximum attainable rise time that is observed due to the displacement of thepreamplifier612 from thestorage cartridge602 to themedia player604.
• FIGS. 7A and 7B illustrate top and bottom views, respectively, of anexample storage cartridge702 that may removably couple with a media player as described with respect to other implementations herein. In one implementation, thestorage cartridge702 does not include an internal preamplifier for amplifying read and write signals.
• Thestorage cartridge702 includes a connector704 designed to electrically mate with a corresponding connector on a media player (not shown). According to one implementation, the media player includes a preamplifier that generates and transmits analog control signals (e.g., read and write signals) across the connector704
• The embodiments of the disclosed technology described herein are implemented as logical steps in one or more computer systems. The logical operations of the presently disclosed technology are implemented (1) as a sequence of processor-implemented steps executing in one or more computer systems and (2) as interconnected machine or circuit modules within one or more computer systems. The implementation is a matter of choice, dependent on the performance requirements of the computer system implementing the disclosed technology. Accordingly, the logical operations making up the embodiments of the disclosed technology described herein are referred to variously as operations, steps, objects, or modules. Furthermore, it should be understood that logical operations may be performed in any order, adding and omitting as desired, unless explicitly claimed otherwise or a specific order is inherently necessitated by the claim language.
• The above specification, examples, and data provide a complete description of the structure and use of exemplary embodiments of the disclosed technology. Since many embodiments of the disclosed technology can be made without departing from the spirit and scope of the disclosed technology, the disclosed technology resides in the claims hereinafter appended. Furthermore, structural features of the different embodiments may be combined in yet another embodiment without departing from the recited claims.

Claims (20)

What is claimed is:

1. A storage system comprising:

a media player including a preamplifier; and

a storage cartridge attached to the media player across an interconnect, the storage cartridge lacking an independent read/write preamplifier and being adapted to perform data access operations responsive to signals received from the media player through the interconnect.

2. The storage system ofclaim 1, wherein the storage system includes multiple storage cartridges, each of the storage cartridges being adapted to receive analog read/write signals generated within the preamplifier of the media player.

3. The storage system ofclaim 2, wherein media player is adapted to selectively couple with each of the multiple storage cartridges.

4. The storage system ofclaim 1, wherein the storage cartridge includes at least one HGA coupled to a flex, the flex including one or more read traces that electrically connect a read element on the HGA to the interconnect, the one or more read traces being impedance-matched to impedance of the read element to reduce reflection of read signals transmitted along the read trace.

5. The storage system ofclaim 1, wherein the storage cartridge includes at least one HGA coupled to a flex, the flex including one or more write traces that electrically connect a write element on the HGA to the interconnect, the write traces being impedance-matched to impedance of the write element to reduce reflection of write signals transmitted along the write trace.

6. The storage system ofclaim 1, wherein the storage cartridge includes:

a flex including electrical traces for routing control signals between the interconnect and an HGA; and

a current shunt mechanism that selectively grounds the electrical traces when the storage cartridge is uncoupled from the media player and selectively ungrounds the electrical traces when the storage cartridge is coupled to the media player.

7. The storage system ofclaim 6, wherein the current shunt mechanism is a micro-electromechanical system (MEMS) switch.

8. The storage system ofclaim 6, wherein the current shunt mechanism selectively interrupts a connection between an HGA and electrical ground responsive to pressure applied at the interconnect.

9. The storage system ofclaim 1, wherein the media player includes a read/write controller that selectively increases overshoot of a write current pulse to improve write transition accuracy

10. A method comprising:

generating, by a preamplifier within a media player, a plurality of analog signals; and

directing the analog signals across an interconnect and to a head gimbal assembly (HGA) within a storage cartridge, the storage cartridge lacking an independent read/write preamplifier

11. The method ofclaim 10, wherein the media player is adapted to provide read and write access to multiple storage cartridges that are each adapted to receive the plurality of analog signals by the preamplifier of the media player.

12. The method ofclaim 10, further comprising:

selectively coupling the media player to a select storage cartridge of multiple storage cartridges.

13. The method ofclaim 10, wherein the HGA is coupled to a flex within the storage cartridge and the flex includes one or more read traces electrically connecting a read element on the HGA to the interconnect, the one or more read traces being impedance-matched to impedance of the read element to reduce reflection of read signals transmitted along the read trace.

14. The method ofclaim 10, wherein the HGA is coupled to a flex within the storage cartridge and the flex includes one or more write traces electrically connecting a write element on the HGA to the interconnect, the one or more write traces being impedance-matched to impedance of the write element to reduce reflection of write signals transmitted along the write trace.

15. The method ofclaim 10, wherein the storage cartridge includes a flex that further includes electrical traces for routing control signals between the interconnect and the HGA and the method further comprises:

selectively grounding the electrical traces when the storage cartridge is uncoupled from the media player and selectively ungrounding the electrical traces when the storage cartridge is coupled to the media player.

16. The method ofclaim 15, wherein selectively grounding and ungrounding the electrical traces further comprises selectively grounding and ungrounding the electrical traces using a micro-electromechanical system (MEMS) switch.

17. The method ofclaim 15, wherein selectively grounding and ungrounding the electrical traces further comprises selectively grounding and ungrounding the electrical traces responsive to pressure applied at the interconnect.

18. A storage system comprising:

multiple storage cartridges that each individually lack a read/write preamplifier; and

a media player adapted to selectively couple with and provide data access to each of the multiple storage cartridges, the media player including a preamplifier that amplifies and transmits analog signals across an interconnect to a select one of the storage cartridges coupled with the media player.

19. The storage system ofclaim 18, wherein each of the multiple storage cartridges includes a head-gimbal assembly (HGA) coupled to a flex and the flex includes read and write traces impedance-matched to corresponding read and write elements on the HGA.

20. The storage system ofclaim 18, wherein each of the storage cartridges includes:

a flex including electrical traces for routing control signals between the interconnect and the HGA; and

a current shunt mechanism that selectively grounds the electrical traces when the select storage cartridge is uncoupled from the media player and selectively ungrounds the HGA when the select storage cartridge is coupled to the media player.

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