Tokyo Kogaku Kikai Kabushiki Kaisha

Kabushiki Kaisha Topcon

University of Miami

Other

Topcon Corporation

Tokyo Kogaku Kikai Kabushiki

Hitoshi Fujii

Takashi Yokokura

Nobuo Hori

Fumio Ohtomo

Jean-Marie Arthur Parel

Takashi Gemma

Satoru Niimura

Hiroaki Shimozono

Katsuhiko Kobayashi

Tsuneo Sasaki

Fumitomo Kondo

Takuji Satoh

Akihiko Sekine

Shinji Wada

Masayuki Hideshima

Kazuo Nunokawa

Hideo Tomoda

Masaru Satoh

Satoh Takuji

A noncontact laser microsurgical apparatus and method for marking a cornea of a patient's or donor's eye in transplanting surgery or keratoplasty, and in incising or excising the corneal tissue in keratotomy, and for tissue welding and for thermokeratoplasty. The noncontact laser microsurgical apparatus comprises a laser source and a projection optical system for converting laser beams emitted from the laser source into coaxially distributed beam spots on the cornea. The apparatus further includes a multiple-facet prismatic axicon lens system movably mounted for varying the distribution of the beam spots on the cornea. In a further embodiment of the method of the present invention, an adjustable mask pattern is inserted in the optical path of the laser source to selectively block certain portions of the laser beams to thereby impinge only selected areas of the cornea.

Noncontact laser microsurgical method

A noncontact laser microsurgical apparatus and method for marking a cornea of a patient's or donor's eye in transplanting surgery or keratoplasty, and in incising or excising the corneal tissue in keratotomy, and for tissue welding during thermokeratoplasty. The noncontact laser microsurgical apparatus comprises a laser source and a projection optical system for converting laser beams emitted from the laser source into coaxially distributed beam spots on the cornea. The apparatus further includes a multiple-facet prismatic axicon lens system movably mounted for varying the distribution of the beam spots on the cornea. In a further embodiment of the method of the present invention, an adjustable mask pattern is inserted in the optical path of the laser source to selectively block certain portions of the laser beams to thereby impinge only selected areas of the cornea.

Noncontact laser microsurgical apparatus

An apparatus for imaging and displaying a blood stream state of an eye to be tested. A laser beam is first irradiated onto an eye to be tested. And light reflected from an irradiated area on the eye is detected and information about the reflected light is stored. And second, the bloodstream state of the eye are calculated on the basis of the information, the imaged results are displayed on a display means of the apparatus. At the same time, a pulse wave of a person to be tested is detected by a pulse wave detecting means, the wave shaped of the pulse wave is displayed by a display controlling means, which controls to display the measuring time and portion of the bloodstream state compositely on the present wave shape.

Apparatus for displaying a bloodstream state

Ophthalmic measuring device

An interferometer for measuring an aspherical shape uses a computer generated hologram. The interferometer comprises a hologram disposed at each of positions conjugate with plural types of aspherical surfaces to be examined and filed lens means disposed between a position conjugate with a convex aspherical surfaces and another position with a concave aspherical surface. The interferometer can measure plural types of aspherical surfaces to be examined without need of changing the position of the interferometer for each of the aspherical surfaces to be examined, even if the number of different surfaces to be examined increases.

Interferometer for measuring aspherical form with the utilization of

A light wave range finder has a range finding optical system in which the intensity of a coherent beam of light emitted from a coherent light source is modulated and delivered to an object and a reflecting beam of light reflected on the object is received by an light receiving element. A distance to the object is measured based on a phase detection of the reflecting beam of light. The range finding optical system has an optical substrate which is provided with, at least, a light intensity modulating portion for modulating the intensity of a coherent beam of light; an optical path changing portion for changing the coherent beam of light, which has been modulated the intensity by the light intensity modulating portion, between an external range finding optical path and a reference optical path; a first light amount regulating portion for regulating a light amount of the coherent beam of light guided to the external range finding optical path; a delivering system for delivering the coherent beam of light which has been regulated the light amount of the first light amount regulating portion toward an object; and a light receiving system for receiving a reflecting beam of light reflected by the object.

Light wave range finder

A range finder for finding a distance to an object comprising an outgoing light guiding wave path, a reference light guiding wave path, and an incoming light guiding wave path. The finder further comprises wavelength changing means for changing the wavelength of the beam of light emitted from the light source, wavelength detecting means for detecting the wavelength of the beam of light emitted from the light source, and calculating means for detecting at least two peaks of the signal coming from the light receiving element when the wavelength of the light source is changed by the wavelength changing means, finding the wavelengths of the light source, respectively, from the wavelength detecting means at the time when the signal exhibits the two peaks, and calculating the distance to the object according to an operation expression memorized beforehand with reference to such obtained two wavelengths. A total reflection prism, a polarized beam splitter, a quarter-wave plate, and a mode converting device are also provided.

Method and apparatus for finding range

A laser beam scanning type ophthalmological instrument has a first laser beam light source for emitting a first laser beam; a second laser beam light source for emitting a second laser beam of a different wavelength from that of the first laser beam; and a light receiving element for receiving a laser beam reflected by an eye fundus, and in which the eye fundus is scanned by the first and second laser beams in order to observe the eye fundus or in order that a view field, etc. can be inspected. The laser beam scanning type ophthalmological instrument is characterized in that the first and second laser beams emitted by the first and second laser beam light sources can independently be adjusted in light quantity.

Laser beam scanning type ophthalmological instrument

An integrated-photocircuit interferometer (20) comprises a substrate (21) in which coherent light for measurement emitted from a light source (23) is directed through an exit waveguide (22) toward a corner cube prism (34) which can be movable with an object to be measured. The light reflected back from the prism (34) can enter an inlet waveguide (33) having branch waveguides (35, 36) which split the incident measurement light. Part of the light transmitted through the exit waveguide (22) is transferred to reference waveguides (26, 27) which provide different optical path lengths for the light propagated therethrough. The 'reference beams of light' which has been transmitted through the different lengths of optical paths provided by the reference waveguides (26, 27) are introduced into the branch waveguides (35, 36) where interference occurs between the reference beams and the split beams of incident light from the corner cube prism (34). The interference will cause changes in brightness detected by photodetectors (37, 38) as the prism (34) is shifted toward or away from the interferometer (20). Since there is an optical path length difference between the reference waveguides (26, 27), a great number of changes can be detected by the photodetectors for a shift of the prism. Thus, the amount of the shift can be determined to a high resolution. In addition, the relationship in phase between the detected brightnesses will change depending on the direction of movement of the corner cube prism (34). The direction of the prism's movement can thus be detected.

Integrated-photocircuit interferometer

A light interferometer has an interferometer portion for interfering a measuring light and a reference light, and a light signal processing portion for processing a signal according to an interference signal which changes according to the change of an optical path length of the measuring light. The interferometer portion has a first light source for generating a coherent light, a light interference portion for dividing the coherent light emitted by the first light source into a reference light and a measuring light in order to introduce the measuring light to an object, making the measuring light reflected by the object and the reference light interfered with each other and introducing thereof to a photo detector, and an optical path length periodically changing means for periodically changing the difference of an optical path length of the reference light with respect to the optical path length of the measuring light relatively at a constant amplitude. The light signal processing portion has a second light source for generating a coherent light, a collimate lens portion for collimating the coherent light emitted by the second light source, a space modulating portion for diffracting the coherent light outgoing from the collimate lens portion, a Fourier transforming portion for transforming the diffracted coherent light, and two photodetectors disposed on at a spot corresponding to a frequency composition equivalent to a frequency of the optical path length periodically changing means and the other at a spot corresponding to a frequency composition two times the first-mentioned frequency composition in order to extract these frequency compositions out of frequency compositions which have been decomposed in frequency spectral by the Fourier transforming portion.

Light interferometer

A laser beam scanning type eye fundus camera has a laser beam generator for generating a laser beam; an illuminating system for illuminating the fundus of an eye to be tested by scanning the laser beam generated by the laser beam generator on the eye fundus; a first and a second light receiving portions for receiving a reflecting light of the laser beam reflected by the eye fundus; a first light receiving system for guiding the reflecting light of the laser beam reflected by the eye fundus to the first light receiving portion; a second light receiving system for guiding a fluorescence excited at the eye fundus by the laser beam; and an electronic circuit for forming an eye fundus image on a monitor TV according to an output signal coming from the first and second light receiving portions.

Laser beam scanning type eye fundus camera

A method of analyzing interference fringes for use in a holographic interferometry process for measuring, by using a computer generated hologram, the shape of an object to be examined. The method comprises:

Method of and apparatus for analyzing interference fringes

A holographic interferometer comprising a source of laser beams, a condenser lens for converging a laser beam supplied from said laser-beam source, a pinhole which allows the passage of said converged laser beam, a collimator lens having a focal point which lies on said pinhole, a beam splitter disposed in an inclined manner between said pinhole and said collimator lens, a spacial filter disposed on the optical axis of a light reflected from said beam splitter and at an optically conjugate position relative to said pinhole, and a hologram standard disposed between said spacial filter and said beam splitter.

Growing community of inventors

Tokyo, Japan

Takashi Yokokura