Patents by Inventor Eiichi Kitajima

Eiichi Kitajima 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: 6087645
    Abstract: An inexpensive remote-controllable laser projection apparatus projects a laser light onto a target object that is located at a prescribed distance from the laser projection apparatus. The laser projection apparatus includes a main body and a remotely controllable reflection target. The main body includes a projection means for projecting the laser light, a reflected light detection means for detecting the reflected light of the projected laser light, a controller, which is connected to the projection means and the reflected light detection means, for controlling the projection of the laser light in multiple operation modes. The reflection target is placed at a position that is separated from the main body, on which prescribed reflection patterns for reflecting the projected laser light are formed.
    Type: Grant
    Filed: May 20, 1998
    Date of Patent: July 11, 2000
    Assignee: Nikon Corporation
    Inventors: Eiichi Kitajima, Hiroshi Kishimoto
  • Patent number: 6057916
    Abstract: An automatic inclination corrector and an inclination sensor using the automatic inclination corrector free from the temperature, for optical instruments. A transparent container 3 seals silicon oil C having a free liquid surface C1. A collimation lens 2 guides the laser beam from the diode 1 to the free liquid surface C1. The inclination corrector corrects the tilt of the instrument to glide the laser beam L4 from the container 3 to advance the beam upward with a normal angle. A reflecting mirror 5 reflects beam L2 after total reflection at the free liquid surface C1. The beam is inverted by a roof prism 6 and passes through silicon oil C and the free liquid surface C1 once. This removes the refractive index n influence to the laser beam L4, and gives an angular change to the laser beam 4 to head the laser beam L4 to a fixed direction.
    Type: Grant
    Filed: December 30, 1996
    Date of Patent: May 2, 2000
    Assignee: Nikon Corporation
    Inventor: Eiichi Kitajima
  • Patent number: 5978076
    Abstract: A reference light generator that is capable of switching the scan plane of a laser beam between the horizontal and the vertical simply by changing the installation position of the reference light generator.A laser beam is emitted from a laser diode 1. A half mirror 3 guides the laser beam to transparent containers 5 and 7. When the reference light generator is used to determine the degree of horizontality, it is installed so that the transparent container 5 is positioned at the top. In this case, a movable light shielding plate 4 blocks the laser beam that travels toward the transparent container 7. The prism effect of a silicon oil 71 inside the transparent container 5 corrects the inclination of the laser beam that passes through the silicon oil 71. A rotation-type pentagonal prism 9 emits only the inclination-corrected laser beam from the reference light generator.
    Type: Grant
    Filed: January 29, 1998
    Date of Patent: November 2, 1999
    Assignee: Nikon Corporation
    Inventor: Eiichi Kitajima
  • Patent number: 5933393
    Abstract: A laser beam projection apparatus includes a light source, a vessel containing a transparent liquid which transmits a light beam from the light source and has a free liquid surface, a condensing optical member for condensing the light beam transmitted through the vessel and the liquid to form a secondary source of the light source, and a first optical member for collimating the light beam from the secondary source into a parallel beam. The focal lengths of the condensing optical member and the first optical member are set in accordance with the refractive index of the liquid. Preferably, the focal lengths are set in accordance with the refractive index of the liquid such that the parallel beam from the first optical member emerges in the vertical direction.
    Type: Grant
    Filed: August 24, 1998
    Date of Patent: August 3, 1999
    Assignee: Nikon Corporation
    Inventor: Eiichi Kitajima
  • Patent number: 5629756
    Abstract: A laser beam projection apparatus is capable of supplying laser beams finely converged on an object at all times irrespective of a distance to the object. The laser beam projection apparatus has a laser beam generator, including a focus adjusting device, for supplying laser beams periodically swept within one plane and, at the same time, converged at a controllable distance, a light receiving element for receiving reflected laser beams from a predetermined object and generating an output signal, a distance calculating unit for calculating a distance to the object on the basis of the output signal and a controller for operating the focus adjusting device so that the swept laser beams are converged in a position corresponding to the calculated distance. The controller can change a sweep speed of the laser beam in accordance with a change in the calculated distance. The controller cna change a sweep speed of the laser beam in accordance with a change in the calculated distance.
    Type: Grant
    Filed: January 31, 1995
    Date of Patent: May 13, 1997
    Assignee: Nikon Corporation
    Inventor: Eiichi Kitajima
  • Patent number: 5589939
    Abstract: Disclosed is a laser surveying system in which devices installed at measuring points are inexpensive and small in weight, and a distribution of codes is not needed for transmitting positional data obtained, this system being capable of continuously quickly making a three-dimensional measurement of the displacement. When the laser beam projected from a light projector sweeps a reflecting device on an object, reflecting surfaces supply the laser beam with positional data. A displacement of the object is measured based on the transmitted positional data from the reflected laser beam.
    Type: Grant
    Filed: February 21, 1996
    Date of Patent: December 31, 1996
    Assignee: Nikon Corporation
    Inventor: Eiichi Kitajima
  • Patent number: 5552886
    Abstract: This invention provides a laser beam transmitting apparatus which can make the levelling work unnecessary to thereby mitigate the burden of an operator and improve work efficiency. The apparatus is provided with a base, a beam transmitter for supplying a beam of light, a housing, for holding the beam transmitter, and a levelling mechanism provided between the housing and the base, the housing being oscillatably supported on the base, and the center of oscillatory movement thereof lying above the centroid of the housing. Thus, there is achieved double bearing combined with a precise levelling mechanism, provided between the beam transmitter and the housing.
    Type: Grant
    Filed: February 27, 1995
    Date of Patent: September 3, 1996
    Assignee: Nikon Corporation
    Inventors: Eiichi Kitajima, Keijun Kishi
  • Patent number: 5293221
    Abstract: A level sensor detects a vertical position of a laser beam emitted from an electronic leveling apparatus and comprises a photo-sensing unit having a predetermined vertical length for detecting the laser beam, a plurality of marking indices arranged on a side edge of a housing of the level sensor at a predetermined pitch along the vertical direction of the laser beam, and analog display unit having a plurality of display devices one for each of the marking indices for displaying a change in an incident position of the laser beam along the vertical direction by selective activation of the display devices.
    Type: Grant
    Filed: March 4, 1992
    Date of Patent: March 8, 1994
    Assignee: Nikon Corporation
    Inventors: Eiichi Kitajima, Akihiko Morishita, Shigeru Isono
  • Patent number: 5049735
    Abstract: The present invention provides an apparatus for detecting a light receiving position, comprising: a light receiving portion including M.times.N light receiving elements arranged along a straight line at a predetermined pitch; a plurality of M digital circuits each for outputting a detection signal when an added level of an input signal exceeds a predetermined level, the M.times.N light receiving elements being connected to the M digital circuits for N by N, respectively; a plurality of N analogue circuits each for outputting the added level of the input signal, the light receiving elements connected to the M digital circuits for N by N respectively being connected to the N analogue circuits by N, respectively; and a calculating means connected to the M digital circuits and the N analogue circuits, for calculating a light receiving position of beam light incident to the light receiving portion, on the basis of outputs from the digital circuits and the analogue circuits.
    Type: Grant
    Filed: July 6, 1990
    Date of Patent: September 17, 1991
    Assignee: Nikon Corporation
    Inventors: Eiichi Kitajima, Akihiko Morishita