Masayuki Kitagawa

US Patent:

6357021, Mar 12, 2002

Filed:

Apr 14, 1999

Appl. No.:

09/291800

Inventors:

Masayuki Kitagawa - Irvine CA
Koji Tsuboi - Irvine CA
Masanori Matsunaga - Irvine CA

Assignee:

Mitsumi Electric Co., Ltd. - Tokyo

International Classification:

G06F 1136

US Classification:

714 41, 714 38, 717 11

Abstract:

A peripheral device and method are provided for reliably updating and checking firmware or other coded information stored within a nonvolatile memory of the device. The device comprises a microcontroller and a memory with a fixed part and an updateable part. Both the fixed part and the updateable part store firmware. When firmware in the updateable part is updated (such as by using a USB connection with a host PC), a first error detection code is generated and stored in the updateable part. As part of an initialization procedure, the firmware stored in the fixed part generates a second error detection code based on the updated firmware stored in the updateable part and compares the second error detection code to the first error detection code stored in the updateable part. If the error detection codes indicate that the firmware stored in the updateable part is valid, the microcontroller uses the firmware stored in the updateable part to operate the device; otherwise, the microcontroller uses firmware stored in the fixed part to operate the device.

US Patent:

6496406, Dec 17, 2002

Filed:

Jun 30, 2000

Appl. No.:

09/607275

Inventors:

Masayuki Kitagawa - Irvine CA

Assignee:

Mitsumi Electric Co., Ltd. - Tokyo

International Classification:

G11C 1300

US Classification:

365106, 365 64

Abstract:

A system connected to a host computer is used to write in or read out data on a disc. The system includes a CD RW controller, a RAM, a processor, and a drive mechanism. The RAM, although functioning as a data buffer, receives instruction codes and variable parameters directly from the host computer. Based on the instruction codes and variable parameters, the processor and the CD RW controller work the drive mechanism to write in and/or read out data on a disc.

US Patent:

6603676, Aug 5, 2003

Filed:

Oct 10, 2002

Appl. No.:

10/268472

Inventors:

Masayuki Kitagawa - Irvine CA

Assignee:

Mitsumi Electric Co., Ltd. - Tokyo

International Classification:

G11C 1300

US Classification:

365106, 365 64

Abstract:

A method of writing in or reading out data on a medium is provided. The method comprises receiving mechanism driving information corresponding to a type of a drive unit from an external apparatus, the drive unit being configured to write in or read out data on a medium. The method also comprises storing the mechanism driving information, and providing the stored mechanism driving information to the drive unit for activation.

US Patent:

6618216, Sep 9, 2003

Filed:

Jul 16, 1998

Appl. No.:

09/116721

Inventors:

Masayuki Kitagawa - Irvine CA

Assignee:

Mitsumi Electric Co., Ltd. - Tokyo

International Classification:

G11B 1514

US Classification:

360 64, 360 46

Abstract:

One aspect of the invention is a digital audio tape (DAT) drive having a plurality of read and write heads. Each of the read and write heads has its own parameters, such as a cut-off frequency and a boost value of a read head, a write current of a write head, etc. The parameters of each head are stored in registers and used when an electrical signal representing digital data is to be written to or read from a magnetic tape is processed. When the electrical signal to be written or to have been read by a specific head is processed, the parameters of the specific head will be provided to an equalizer or a pre-amplifier. In the reading process, because the optimum cut-off frequency and boost value are used for a specific read head, the processed electrical signal more accurately represents the digital data recorded on the magnetic tape. In the writing process, the optimum write current to a specific write head makes the write head generate a sufficient magnetic field to magnetize the write head. Therefore, the reliability of read and write operations of a DAT drive is greatly improved.

US Patent:

6708231, Mar 16, 2004

Filed:

Aug 12, 1999

Appl. No.:

09/372485

Inventors:

Masayuki Kitagawa - Irvine CA

Assignee:

Mitsumi Electric Co., Ltd. - Tokyo

International Classification:

G06F 1136

US Classification:

710 10, 713 1, 714 3

Abstract:

The present invention provides systems and methods for performing a firmware update. In one embodiment, a peripheral reset signal is masked in response to a peripheral firmware update command. The firmware update is loaded into a peripherals nonvolatile memory while the reset signal is masked.

US Patent:

6820166, Nov 16, 2004

Filed:

Jan 9, 2001

Appl. No.:

09/757314

Inventors:

Masayuki Kitagawa - Irvine CA

Assignee:

Mitsumi Electric Co., Ltd. - Tokyo

International Classification:

G06F 1300

US Classification:

710316, 710313

Abstract:

The present invention relates to a method and system for selecting one of the two functions. The system in accordance with one embodiment of the invention includes a first entity that has a host function and a device function, and a second entity that has at least one of the two functions. The system further includes a detector and a selecting mechanism. The detector detects the second entity when the first entity is connected to the second entity. The selecting mechanism responds to an output of the detector and selects one out of the host and device functions of the first entity.

US Patent:

6862258, Mar 1, 2005

Filed:

May 1, 2001

Appl. No.:

09/846658

Inventors:

Masayuki Kitagawa - Irvine CA, US

Assignee:

Mitsumi Electric Co., Ltd. - Tokyo

International Classification:

G11B003/90

US Classification:

369 533, 369 4733, 369 4738

Abstract:

An optical drive that detects a communication link interface speed to a host device and changes an optical media writing speed to reduce the likelihood that an error will occur during writing caused by an insufficient data interface rate in relation to the writing speed. In certain embodiments, the process for detecting and storing the preferred recording speed may be a software module which is part of the firmware of the optical drive. The invention provides a method of determining the preferred recording speed based on the interface speed and the maximum recording speed of the optical drive and storing this preferred recording speed for retrieval during recording of optical media.

US Patent:

20040030742, Feb 12, 2004

Filed:

Aug 6, 2002

Appl. No.:

10/214945

Inventors:

Masayuki Kitagawa - Santa Clara CA, US

International Classification:

G06F015/16

US Classification:

709/203000

Abstract:

The invention relates to a system for communicating data with at least one of an external host computer and at least one digital device. The system comprises a first entity and a second entity. The first entity is configured to operate based on received commands. The second entity is in data communication with the first entity and the at least one digital device. The second entity is configured to perform a hub or host function with respect to a selected one of the first entity and the digital device and, at the same time, to perform the hub or host function with respect to the other of the first entity and the digital device.