Tomey Corporation

Yuji Nozawa

Chihiro Kato

Takashi Kamo

Tsutomu Ohmori

Keiichiro Okamoto

Masahiro Yamanari

Satoshi Sugiyama

Takashi Sugaya

An ophthalmic apparatus may include: a wavelength sweeping light source; a reference optical system; a calibration optical system; a light receiving element configured to receive calibration interference light which is a combination of calibration light and reference light; and a signal processor configured to sample a calibration interference signal outputted from the light receiving element when it receives the calibration interference light. The signal processor may sample the calibration interference light in at least first and second frequency bands, which are different and used for measuring a specific region of a subject eye. The ophthalmic apparatus calculates a difference between first and second waveforms, the first waveform being a waveform of the calibration interference signal that is sampled in the first frequency band and Fourier transformed, the second waveform being a waveform of the calibration interference signal that is sampled in the second frequency band and Fourier transformed.

Ophthalmic apparatus

An optical coherence tomographic device configured to acquire a tomographic image of a subjected eye is disclosed herein. The optical coherence tomographic device may include a light source of wavelength sweeping type; and a measurement optical system configured to irradiate the subjected eye with light outputted from the light source, where D/S&#xd7;&#x3bb;&#x3e;1.61 may be satisfied, with a diameter of the light outputted from the light source at an incident position to the subjected eye is D, a wavelength swept frequency of the light source is S, and a center wavelength of the light outputted from the light source is &#x3bb;.

Optical coherence tomographic device and light source

An ophthalmic apparatus includes: a light source; a measurement optical system that irradiates an eye with light from the source and guides reflected light from the eye; a reference optical system that guides the light from the source to use the light from the source as reference light; an abnormality detection optical system that has an optical path length of a predetermined length and to guide the light from the source to use the light from the source as abnormality detection light; a light receiving element that receives measurement interference light being combination of the reflected light from the eye and the reference light and abnormality detection interference light being combination of the abnormality detection light and the reference light, and the ophthalmic apparatus determines whether the measurement interference light is abnormal based on waveform of an abnormality detection interference signal outputted from the light receiving element.

An ophthalmic apparatus that includes a light source of wavelength sweeping type; a measurement optical system; a reference optical system; a light receiving element that receives interference light; a sample clock signal generator that generates a sample clock signal from the light from the light source, the sample clock signal cyclically changing at equal frequency intervals; a signal processor that samples an interference signal based on the sample clock signal, the interference signal being outputted from the light receiving element when the light receiving element receives the interference light. The ophthalmic apparatus generates period data based on the sample clock signal, the period data indicating a relationship between a period of the sample clock signal and time; and determines a processing duration of the interference signal sampled at the signal processor based on the period data.

An ophthalmological device emits light from a measurement optical system to an eye to be examined and calculates a dimension along the eye axis of a target portion of the eye from interfering light composed of reflected light from the eye and reference light. The measurement optical system includes incidence position changing member that changes the incidence position of light emitted to the eye, and driving unit that drives the incidence position changing member so as to scan at the incidence position of emitted light in a predetermined region of the eye. The predetermined region is a region where a straight line passes through when the straight line radially extended from the cornea apex of the eye is circumferentially moved over a predetermined angle range in the case of the eye is viewed from the front.

Ophthalmological device

An ophthalmologic apparatus comprises a light source, an optical measurement systemthat radiates first light from the light source to inside an eye to be examined and guides first reflected light from the eye, an optical reference system () that radiates second light from the light source to a reference surface and guides second reflected light from the reference surface, a photo detectorthat detects interfering light between the first reflected light from the optical measurement system and the second reflected light from the optical reference system, and a processor that determines a position of a measuring portion of the inside of the eye based on the detected interfering light. The optical measurement system comprises an incident angle changing memberthat changes an incident angle of the first light radiated to the eye within a predetermined angular range relative to an axis of vision of the eye.

Ophthalmologic apparatus for measuring position of measuring portion inside eye

Ophthalmological device for measuring ocular dimensions

An ophthalmological device calculates a cornea surface shape of an eye to be examined. The ophthalmological device includes a ring image photographic optical system configured to radiate a plurality of concentric ring light to the cornea surface of the eye and take reflected images of the plurality of ring light reflected from the cornea surface of the eye, an interference optical system configured to radiate measurement light to the eye and detect interfering light composed of reflected light of the measurement light reflected from the eye and predetermined reference light. The shape of the cornea anterior surface of the eye is calculated form the reflected images of the plurality of ring light, the thicknesses of the cornea of the eye at the plurality of incident positions is calculated from the interfering light, and the posterior surface shape of the cornea of the eye is calculated based on these two results.

A wavelength-swept light source apparatus comprises a light source that emits a wavelength-swept light that varies in a predetermined cycle, a mode hop detector that detects a mode hop of the wavelength-swept light emitted from the light source; and a control unit that controls at least one of a parameter that defines a specified period having a predetermined fixed or variable time length provided in the predetermined cycle and a control parameter of the light source, thereby to set an occurrence timing of the mode hop detected by the mode hop detector outside of the specified period.

Wavelength-swept light source apparatus and measuring apparatus

Provided is an optical tomographic device including a measurement optical system that irradiates light from a light source to inside a subject and guides reflected light therefrom; a reference optical system that guides the light from the light source as reference light; a calibration optical system that irradiates a calibration reflecting surface with light from the light source, and guides the reflected light reflected by the calibration reflecting surface; a light-receiving element that receives the interfering light for measurement formed by synthesizing the reflected light guided by the measurement optical system and the reference light, and the interfering light for calibration formed by synthesizing the reflected light guided by the calibration optical system and the reference light; and an arithmetic logic unit that corrects the received interfering light for measurement by using an analysis result obtained by analyzing the received the interfering light for calibration.

Optical coherence tomography device having a plurality of calibration reflecting surfaces

An ophthalmic apparatus is provided with a light source, an optical measurement system, an optical reference system, an optical calibration system, a light receiving element, and a processor. The light receiving element receives an interference light for measurement produced by both the reflected light guided by the optical measurement system and the reference light guided by the optical reference system, and also receives an interference light for calibration produced by the calibration light guided by the optical calibration system and the reference light guided by the optical reference system. The processor determines a position of a measuring portion inside an eye to be examined by Fourier-analyzing the interference light for measurement and the interference light for calibration.

Growing community of inventors

Nagoya, Japan

Yuji Nozawa