Patents Assigned to Plasmon LMS, Inc.
-
Patent number: 7248557Abstract: For the purpose of providing sector-address information on optical disks, a robust header is realized by utilizing a very simple encoding method that allows asynchronous reading. In order to provide robustness and reliability, the header uses a biphase data format to encode addressing information. The embossed header is further configured with redundant address-fields in a checkerboard pattern between adjacent tracks, in order to provide robustness for media-contamination. Each address-field starts with a unique address-mark and ends with parity-check information to provide reliable error-detection. The entire header can be decoded without the need for a slice-level, thus making it very tolerant to amplitude-variations and DC-offset variations. By combining these characteristics, a header is achieved which is reliable and inherently resistant to failures in providing sector-address information on optical disks.Type: GrantFiled: December 30, 2003Date of Patent: July 24, 2007Assignee: Plasmon LMS, Inc.Inventors: Johannes J. Verboom, John C. Rathe
-
Publication number: 20070097825Abstract: A waveform reconstructor is utilized in the read channel of an optical storage system in order to produce a high speed and reliable data output. Generally speaking, the waveform reconstructor provides readout signals from the optical storage media without utilizing a phase locked loop. In order to accomplish this, readout signals are first converted to digital signals, then provided to a digital equalizer for further signal conditioning. This equalizer use provides several advantages not available when PLL designs are utilized. Readout samples are then processed to determine a phase error, as compared with an ideally sampled signal. Once determined, this phase error allows for the reconstruction of the waveform, to create an output which is consistent with one which would have been sampled at precisely the correct time. The waveform reconstructor manages the calculated samples to determine whether actual asynchronous sampling is inconsistent with the anticipated samples.Type: ApplicationFiled: October 31, 2005Publication date: May 3, 2007Applicant: Plasmon LMS, Inc.Inventor: Keith Holstine
-
Patent number: 7209414Abstract: A method for minimizing spherical aberration in an optical read/write drive caused by variances in lens thickness and laser wavelength. The method provides an economic solution that pairs objective lenses with laser diodes such that the spherical aberration caused by the objective lens is offset by the spherical aberration caused by the laser wavelength, thereby minimizing or completely canceling the overall spherical aberration.Type: GrantFiled: May 27, 2003Date of Patent: April 24, 2007Assignee: Plasmon LMS, IncInventors: Robert G. Russell, Ronald P. Stahl
-
Patent number: 7200771Abstract: A method is provided that minimizes the seek time necessary for relocating bad sectors found during data processing. During standard data processing in the prime disk area, identified bad sectors are saved in memory until after all of the data processing has been completed. The bad sectors are then relocated from memory in a batch process, thereby requiring only a single seek command to the defect management area. This procedure reduces the time penalty in the number of relocations to a near constant time and avoids a linear time penalty.Type: GrantFiled: November 12, 2003Date of Patent: April 3, 2007Assignee: Plasmon LMS, Inc.Inventors: David A. Bolt, Brian Worby
-
Publication number: 20070047395Abstract: Data protection and security is provided by incorporating a data shredding operation which renders data previously stored on storage media unrecoverable. In the shredding operation of the present invention, certain overhead portions of a data storage sector remain unchanged, while the data area is overwritten with a predetermined pattern. By maintaining the overhead portions of the sectors (addressing, verify and protect, error correction codes, etc.) the sectors can be easily identified as being previously shredded, thus not providing a source of possible confusion to the data storage device. Further, the data becomes unrecoverable as it has been overwritten by the predetermined pattern, which thus eliminates all previously existing transitions which contained the encoded data.Type: ApplicationFiled: August 25, 2006Publication date: March 1, 2007Applicant: Plasmon LMS, Inc.Inventors: Bruce Skeeter, Brian Worby, Keith Holstine, David Bolt
-
Publication number: 20060209663Abstract: In order to help maximize the capacity of an optical storage device, and increase the efficiency of addressing, a unique addressing scheme is utilized to provide addressing for an optical storage disk. Importantly, this scheme is compatible with multilayer disks and helps to minimize the potential for errors. In the addressing scheme of the present invention, the storage media is provided with a wobbled groove, which includes addressing information for the media. More specifically, the surface of the media is divided into predetermined sections, or portions, each portion having a selected number of wobble periods. Within these wobble periods, the amplitude of one single wobble period is either reduced or eliminated. The location of this reduced or eliminated wobble signal can then be determined by the readout system of the present invention and utilized to provide addressing information.Type: ApplicationFiled: March 21, 2005Publication date: September 21, 2006Applicant: Plasmon LMS, Inc.Inventors: Johannes Verboom, Kurt Getreuer
-
Patent number: 6961291Abstract: An auto-focus system for a DVD reader or other optical access unit which reads and/or writes information from/to at least two information layers on an optical storage medium such as a DVD or DVR. The auto-focus system includes an astigmatic lens. A confocal aperture is placed at the first focal line image generated by the astigmatic lens from light rays reflected from the addressed information layer. The placement of the confocal aperture allows extraneous out-of-focus light rays reflected from non-addressed information layers to be blocked from reaching the photo detector array which then creates a focus error signal (FES). The FES drives a servo assembly connected to an access head of the optical access unit, bringing the access head into focus. In some embodiments, the confocal aperture is “bow-tie” shaped, allowing for simplified assembly and easing in-plane rotational alignment.Type: GrantFiled: April 3, 2002Date of Patent: November 1, 2005Assignee: Plasmon LMS, Inc.Inventors: Kurt Walter Getreuer, Ronald Paul Stahl
-
Patent number: 6891868Abstract: In order to provide a low noise laser beam, a noise reducing feedback network is provided which creates a noise reducing signal and provides that signal to the laser itself. In order to produce the noise reducing signal, the operation of the laser is monitored and the feedback signal is a direct result of this monitoring. Monitoring is accomplished by a fast-forward sense detector, which receives a portion of the laser beam from the operating laser. The output from this fast-forward sense detector is provided to an amplifier which inverts and amplifies the signal. A noise reduction feedback network then receives the amplified signal, appropriately filters this signal, and provides it to the laser itself so as to reduce noise in the laser-beam for the frequency band of importance for reading the recorded data from the optical medium.Type: GrantFiled: May 8, 2001Date of Patent: May 10, 2005Assignee: Plasmon LMS, Inc.Inventors: Johannes J. Verboom, Jeffrey M. Brooke, Gary L. Kline
-
Publication number: 20040017749Abstract: In order to minimize potential damage to a rewritable storage media, and to consequently extend the life of the media, the laser power is carefully controlled in order to avoide sharp power transitions. Rather than simply turning the laser power on to its full power level, the power utilized during writing dedicated sections of data sectors is transitioned from 0 to its full power level over a desired period of time. In this way, the thermal shock caused by repeated rewriting in these areas can be minimized, thus extending the life of the rewritable media.Type: ApplicationFiled: July 24, 2002Publication date: January 29, 2004Applicant: Plasmon LMS, Inc.Inventors: Jeffrey M. Brooke, Johannes J. Verboom, Robert Longman, Robert Somekh, Paul Blanchard, Gary L. Kline
-
Patent number: 6487146Abstract: Writing predetermined data pattern to an allocated segment of a disk drive and appropriately reading that one data pattern while varying the read focus characteristics provides for efficient and effective read focus optimization in an optical disk drive. In order to produce helpful data, the read focus offset is varied while reading the different segments of the data pattern, thus producing read out signals with different peak to peak amplitudes. This is compared to data which is obtained by reading the same data pattern while the offset is held constant. Optimization of the read focus offset is carried out and made possible by appropriate analysis of the waveforms produced when reading the predetermined data pattern in these two reading passes. By appropriately tracking the results of the various read focus offsets, an optimum read focus offset can be easily determined.Type: GrantFiled: March 13, 2000Date of Patent: November 26, 2002Assignee: Plasmon LMS Inc.Inventor: Johannes J. Verboom
-
Patent number: 6467014Abstract: Automated address mapping is achieved by a system and methodology which automatically reacts to changes in the disk configuration. Prior to utilizing the disk, disk configuration information is provided by the user resulting in a stored configuration table. This configuration table is then used to compute an address translation structure which can be later used to perform actual address mapping operations. Utilizing this address translation structure, in combination with appropriate formulas, address mapping from a logical block address, provided by the host computer, to a surface-track-sector address (STSA) is easily accomplished. By having the actual address translations dependent upon the configuration table, the system and method automatically reacts to changes in the disk configuration.Type: GrantFiled: February 29, 2000Date of Patent: October 15, 2002Assignee: Plasmon LMS, Inc.Inventor: David A. Bolt
-
Patent number: 6407970Abstract: A method, circuit and system for selectively and adaptively effecting conditioning of selected samples of a read signal in storage technologies. A circuit embodying the present invention includes sample logic, arithmetic logic and conditioning logic. The sample logic receives samples and provides a main sample and one or more selected neighbor samples. The arithmetic logic compares the main sample to the neighbor samples toward determining satisfaction of selected conditioning criteria. If the selected conditioning criteria are satisfied, the conditioning logic selectively and adaptively effects level conditioning as to the main sample. Further, the level conditioning is combined with a rule compliance system to insure the read data is following the protocol of the data coding format being used.Type: GrantFiled: January 23, 2001Date of Patent: June 18, 2002Assignee: Plasmon LMS, Inc.Inventor: Johannes J. Verboom
-
Patent number: 6205103Abstract: A method, circuit and system for selectively and adaptively effecting conditioning of selected samples of a read signal in storage technologies. A circuit embodying the present invention includes sample logic, arithmetic logic and conditioning logic. The sample logic receives samples and provides a main sample and one or more selected neighbor samples. The arithmetic logic compares the main sample to the neighbor samples toward determining satisfaction of selected conditioning criteria. If the selected conditioning criteria are satisfied, the conditioning logic selectively and adaptively effects level conditioning as to the main sample. Further, the level conditioning is combined with a rule compliance system to insure the read data is following the protocol of the data coding format being used.Type: GrantFiled: April 28, 2000Date of Patent: March 20, 2001Assignee: Plasmon LMS, Inc.Inventor: Johannes J. Verboom
-
Patent number: 5999042Abstract: A switchable active filter circuit is formed which employs a ground based switch to direct a portion of a feedback current away from a virtual ground terminal of an operational amplifier, thereby providing enhanced circuit Q and greater phase control at frequencies approaching an octave from the unity gain crossover frequency of an operational amplifier used to form the filter. The circuit employs a switchable feedback tee which includes a first capacitor, a second capacitor, a third capacitor and a switch. The first capacitor and the second capacitor form a first series circuit which is connected from the output terminal to the input terminal of the operational amplifier. The third capacitor and the first switch are connected as a second series circuit which is coupled from circuit ground potential to a junction of the first capacitor and the second capacitor.Type: GrantFiled: March 30, 1998Date of Patent: December 7, 1999Assignee: Plasmon LMS, Inc.Inventors: Hakan O. Hemdal, Jeffrey M. Brooke
-
Patent number: 5975450Abstract: An x-y positioning system having a reduced footprint for use in a tape library mountable in standard electronics racks incorporates a cantilevered x-axis frame movably mounted to a single y-axis rail. A rotation preventer is mounted to one end of the frame for stability. An elevator mounted to the x-axis frame for translation in that axis carries a gripper for cartridge handling. The gripper is aligned with individual cartridges contained in tape library magazines by the x and y motion of the elevator. The gripper mechanism provides pass-through handling of tape cartridges for insertion and removal from tape transport units and storage magazines.Type: GrantFiled: September 16, 1996Date of Patent: November 2, 1999Assignee: Plasmon LMS, Inc.Inventors: Gregory S. Leger, Scott R. Patterson, Ryan S. Porter
-
Patent number: D466902Type: GrantFiled: January 15, 2002Date of Patent: December 10, 2002Assignee: Plasmon LMS, Inc.Inventor: Coen J. Warmenhoven