Patents by Inventor Takatoshi Yoshikawa

Takatoshi Yoshikawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20020184492
    Abstract: A license server (10) includes a CRL database (306) holding a revocation list recording therein classes predetermined corresponding respectively to a memory device, such as a memory card, and a content reproduction circuit, such as a cellular phone, that are subjected to revocation of distributing, reproducing and transferring content data. A distribution control unit (315) suspends an operation distributing content data if the distribution is addressed to a class listed on the revocation list. The revocation list is also held in the memory card and distribution control unit (315) in distributing content also transmits information for updating the revocation list in the memory card.
    Type: Application
    Filed: May 31, 2002
    Publication date: December 5, 2002
    Inventors: Yoshihiro Hori, Toshiaki Hioki, Miwa Kanamori, Takatoshi Yoshikawa, Hiroshi Takemura, Masataka Takahashi, Takayuki Hasebe, shigeki Furuta, Takahisa Hatakeyama, Tadaaki Tonegawa, Takeaki Anazawa
  • Publication number: 20020184154
    Abstract: A memory card (110) conducts an authentication process with a server based on data stored in an authentication data hold unit (1400). The memory card (110) extracts a first session key (Ks1) from a server by a decryption process and a transaction ID from the data applied on a data bus (BS3). The memory card (110) generates a second session key (Ks2) through a session key generation unit (1418), and transmits to the server, as the keys to encrypt content data in receiving decryption of content data, the second session key (Ks2) and a key (KPm(1)) unique to the memory card (110) in an encrypted state with the first session key (Ks1). The transaction ID and the second session key (Ks2) stored in the log memory (1460) are used in the redistribution process.
    Type: Application
    Filed: May 31, 2002
    Publication date: December 5, 2002
    Inventors: Yoshihiro Hori, Toshiaki Hioki, Miwa Kanamori, Takatoshi Yoshikawa, Hiroshi Takemura, Masataka Takahashi, Takayuki Hasebe, Shigeki Furuta, Takahisa Hatakeyama, Tadaaki Tonegawa, Takeaki Annazawa
  • Publication number: 20020183985
    Abstract: A cellular phone (100) stores encrypted content data and encrypted license key distributed thereto in a memory card (110). The cellular phone (100) and the memory card (110) collectively perform a part of mutual authentication processing upon power-on. The encrypted license key (Kc) read from the memory card (110) is decrypted by a first decryption processing portion (1510) with a session key (Ks4), and is further decrypted by a second decryption processing portion (1514) with a system symmetric key (Kcom) for extraction. A third encryption processing portion (1516) decrypts the encrypted content data read from memory card (110) with the license key (Kc) to reproduce content data (Data).
    Type: Application
    Filed: June 6, 2002
    Publication date: December 5, 2002
    Inventors: Yoshihiro Hori, Toshiaki Hioki, Miwa Kanamori, Takatoshi Yoshikawa, Hiroshi Takemura, Takayuki Hasebe, Takahisa Hatakeyama, Tadaaki Tonegawa, Takeaki Anazawa
  • Publication number: 20020176580
    Abstract: In a cellular phone, a controller stores content data received from a distribution server into a memory. When the content data is to be transmitted to a memory card, a random number key generator generates a license key, and an encryption processing unit encrypts the content data using the license key. The controller transmits encrypted content data to a memory card via a memory card interface. Then, the controller deletes the content data stored in the memory. As a result, distribution of content data that must be deleted when transferring to another apparatus can be facilitated while protecting the copyright.
    Type: Application
    Filed: May 23, 2002
    Publication date: November 28, 2002
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Keiji Horiuchi, Takatoshi Yoshikawa, Toshiaki Hioki, Yoshihiro Hori
  • Publication number: 20020131594
    Abstract: A controller of a reproduction terminal determines whether a block read from a memory card is an encrypted block or a non-encrypted block, and then applies the read block to a content decrypting circuit. The controller stops application of the block to the content decrypting circuit when the non-encrypted blocks of P or more in number are continuously read from the memory card. Consequently, reproduction of the encrypted content data can be stopped if the encrypted content data includes a continuous non-encrypted portion of a predetermined length or more.
    Type: Application
    Filed: September 10, 2001
    Publication date: September 19, 2002
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Yoshihiro Hori, Takatoshi Yoshikawa
  • Patent number: 6188790
    Abstract: An apparatus for recognizing characters read by a reading unit. A circumscribing rectangle of a read character is formed, and the degree of narrowness of that circumscribing rectangle is acquired. Characters having a degree of narrowness that is equal to or greater than a predetermined value are selected and blank areas are added to the circumscribing rectangle to yield a character area with a corrected degree of narrowness. The character is normalized by converting the character area to a specified size, and is recognized based on the normalized character. It is therefore possible to normalize even characters significantly elongated vertically or horizontally for easier recognition and to group their character patterns.
    Type: Grant
    Filed: February 26, 1997
    Date of Patent: February 13, 2001
    Assignee: Tottori Sanyo Electric Ltd.
    Inventors: Takatoshi Yoshikawa, Hiromitsu Kawajiri, Hiroshi Horii, Junji Tanaka
  • Patent number: 5991439
    Abstract: A hand-written character recognition apparatus includes a CIS, and image data of each character of addressing information hand-written on a transmission original, which is read by the CIS, is stored in a bit-mapped line buffer. A histogram of one direction, e.g. an X direction (main scanning direction) is produced on the basis of the image data, and the histogram is stored in the histogram buffer. A rough position of each of the characters is evaluated on the basis of the histogram, and a character width of each of the characters, preferably an average character width is evaluated with referring to the line buffer. Then, a blank portion having a size of 1.5 times or less the average character width is detected as a space between characters.
    Type: Grant
    Filed: May 15, 1996
    Date of Patent: November 23, 1999
    Assignees: Sanyo Electric Co., Ltd, Tottori Sanyo Electric Co., Ltd.
    Inventors: Junji Tanaka, Takatoshi Yoshikawa, Hiromitsu Kawajiri, Hideko Taniguchi, Shigetoshi Matsubara
  • Patent number: 5502461
    Abstract: On a liquid crystal display panel of the handwritten character input system, a data input frame is displayed, and in the data input frame, a plurality of character writing frames are displayed. Each of the character writing frames defines an area to which a handwritten character can be input. In a frame number changing mode, when the size of the data input frame is changed, the number of character writing frames is changed in accordance with the change size. In a frame size changing mode, when the size of the data input frame is changed, the size of the character writing frame is changed in accordance with the changed size. Further, when the size of the character writing frame is changed, the character font to be displayed is also changed in accordance with the changed size.
    Type: Grant
    Filed: April 8, 1994
    Date of Patent: March 26, 1996
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masayoshi Okamoto, Takatoshi Yoshikawa, Kazuhiro Ieda, Hiroshi Horii