Patents by Inventor Chung-Wen Lan

Chung-Wen Lan 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).

  • Patent number: 6926771
    Abstract: A method for growing stoichiometric lithium niobate and lithium tantalate single crystals is provided. A crystal growing apparatus that includes a long crucible with a separation member therein is used. A solid feed material is quenched from a molten state, solidified in batches or sintered before charged in the long crucible to obtain substantially stoichiometric solids. The separation member divides the long crucible into a melting zone and a feeding zone located under the melting zone, and it could effectively prevent bubble formation in the growing crystal. The stoichiometry of the axial and radial composition can be well controlled, and the control of the diameter of the crystal body is easily achieved as well.
    Type: Grant
    Filed: August 27, 2002
    Date of Patent: August 9, 2005
    Assignee: National Taiwan University
    Inventor: Chung-Wen Lan
  • Patent number: 6916371
    Abstract: A method for growing stoichiometric lithium niobate and lithium tantalate single crystals is provided. A crystal growing apparatus that includes a long crucible with a separation member therein is used. A solid feed material is quenched from a molten state, solidified in batches or sintered before charged in the long crucible to obtain substantially stoichiometric solids. The separation member divides the long crucible into a melting zone and a feeding zone located under the melting zone, and it could effectively prevent bubble formation in the growing crystal. The stoichiometry of the axial and radial composition can be well controlled, and the control of the diameter of the crystal body is easily achieved as well.
    Type: Grant
    Filed: August 5, 2003
    Date of Patent: July 12, 2005
    Assignee: National Taiwan University
    Inventor: Chung-Wen Lan
  • Publication number: 20040103840
    Abstract: A method for growing stoichiometric lithium niobate and lithium tantalate single crystals is provided. A crystal growing apparatus that includes a long crucible with a separation member therein is used. A solid feed material is quenched from a molten state, solidified in batches or sintered before charged in the long crucible to obtain substantially stoichiometric solids. The separation member divides the long crucible into a melting zone and a feeding zone located under the melting zone, and it could effectively prevent bubble formation in the growing crystal. The stoichiometry of the axial and radial composition can be well controlled, and the control of the diameter of the crystal body is easily achieved as well.
    Type: Application
    Filed: August 5, 2003
    Publication date: June 3, 2004
    Inventor: Chung-Wen Lan
  • Patent number: 6645294
    Abstract: A rotational directional solidification crystal growth system includes a vertical furnace, a crucible, and a rotate support device. The vertical furnace contains a high-temperature portion and a low-temperature portion. The crucible has a seed well and a growth region. The seed well and the growth region contain a seed crystal and raw material, respectively. The crucible moves from the high-temperature portion of the furnace to the low-temperature portion of the furnace or the thermal profile moves related to a stationary crucible to proceed the crystal growth. The rotation support device supports and rotates the crucible, and the tangent velocity of the rotated crucible is no less than about 5&pgr;/3 cm/s.
    Type: Grant
    Filed: January 3, 2002
    Date of Patent: November 11, 2003
    Assignee: National Taiwan University
    Inventors: Chung-Wen Lan, Ya-Wen Yang
  • Publication number: 20030159645
    Abstract: A method for growing stoichiometric lithium niobate and lithium tantalate single crystals is provided. A crystal growing apparatus that includes a long crucible with a separation member therein is used. A solid feed material is quenched from a molten state, solidified in batches or sintered before charged in the long crucible to obtain substantially stoichiometric solids. The separation member divides the long crucible into a melting zone and a feeding zone located under the melting zone, and it could effectively prevent bubble formation in the growing crystal. The stoichiometry of the axial and radial composition can be well controlled, and the control of the diameter of the crystal body is easily achieved as well.
    Type: Application
    Filed: August 27, 2002
    Publication date: August 28, 2003
    Inventor: Chung-Wen Lan
  • Publication number: 20030079675
    Abstract: A rotational directional solidification crystal growth system includes a vertical furnace, a crucible, and a rotate support device. The vertical furnace contains a high-temperature portion and a low-temperature portion. The crucible has a seed well and a growth region. The seed well and the growth region contain a seed crystal and raw material, respectively. The crucible moves from the high-temperature portion of the furnace to the low-temperature portion of the furnace or the thermal profile moves related to a stationary crucible to proceed the crystal growth. The rotation support device supports and rotates the crucible, and the tangent velocity of the rotated crucible is no less than about 5&pgr;/3 cm/s.
    Type: Application
    Filed: January 3, 2002
    Publication date: May 1, 2003
    Inventors: Chung-Wen Lan, Ya-Wen Yang
  • Patent number: 5217565
    Abstract: Floating zone refining or crystal growth is carried out by providing rapid relative rotation of a feed rod and finish rod while providing heat to the junction between the two rods so that significant forced convection occurs in the melt zone between the two rods. The forced convection distributes heat in the melt zone to allow the rods to be melted through with a much shorter melt zone length than possible utilizing conventional floating zone processes. One of the rods can be rotated with respect to the other, or both rods can be counter-rotated, with typical relative rotational speeds of the rods ranging from 200 revolutions per minute (RPM) to 400 RPM or greater. Zone refining or crystal growth is carried out by traversing the melt zone through the feed rod.
    Type: Grant
    Filed: November 13, 1991
    Date of Patent: June 8, 1993
    Assignee: Wisconsin Alumni Research Foundation
    Inventors: Sindo Kou, Chung-Wen Lan