Kabushiki Kaisha Topcon

Tokyo Kogaku Kikai Kabushiki Kaisha

Kouji Nishio

Yoshihiko Hanamura

Yasufumi Fukuma

Hiroshi Iijima

Katsuhiko Kobayashi

Kenjiro Katsuragi

Akio Morimoto

Masaru Sato

Hiroyuki Ohtsuka

Gaku Takeuchi

Masahiro Shibutani

Akinari Takagi

Kenjirou Katsuragi

An eye's optical characteristics measuring system, comprising a target projecting means for projecting a target image on a fundus of an eye under test, a photodetecting means for guiding the target image toward a photoelectric detector, a pupil diameter measuring means, a calculating means for calculating optical characteristics of the eye under test according to distribution of optical intensity obtained based on an image acquired by the photoelectric detector, and an aperture selecting means provided on each of the target projecting means and the photodetecting means, wherein the aperture selecting means is independently driven, and apertures to restrict a projecting luminous flux and a photodetecting luminous flux are selected based on a pupil diameter of the eye under test measured by the pupil diameter measuring means.

Eye's optical characteristics measuring system

An eye's optical characteristics measuring system, comprising a first target projection optical system for projecting a target image on a fundus of an eye under test, a first photodetecting means for receiving the target image reflected from the fundus of the eye under test from the first target image projecting optical system, an ocular refractive power measuring unit for measuring ocular refractive power of the eye under test based on photodetection result from the first photodetecting means, a second target projecting means for projecting a spot-like target image to the fundus of the eye under test, a second photodetecting means for receiving the target image reflected from the fundus of the eye under test, and an eye's optical characteristics measuring unit for measuring ocular refractive power based on two or more images acquired at a predetermined refractive degree pitch before and after centering the refractive degree of the eye under test obtained by the second photodetecting means.

A corneal endothelial cell measuring instrument comprises a monitor for displaying a corneal endothelial cell image picked up, an input device for marking the centers of cell images in the corneal endothelial cell image displayed on the screen of the monitor, a processor for determining the coordinate value of the marked centers, forming a closed curve formed by connecting the plurality of the marked centers, calculating the area of a region enclosed by the closed curve and calculating cell density, i.e., the number of cells per unit area, from the number of the centers on the closed curve and the number of the centers inside the closed curve.

Corneal endothelial cell measuring instrument

A corneal endothelial cell photographing apparatus comprises a first slit plate provided with a slit, a photographing light projecting optical system for obliquely projecting photographing light for photographing a corneal endothelial cell of an eye to be tested through the slit of the first slit plate on the eye, an observation light projecting optical system for projecting observation light through the slit of the first slit plate on the eye for observation prior to photographing the corneal endothelial cell of the eye, an observing and photographing optical system for guiding the observation light reflected from the cornea of the eye and the photographing light reflected from the cornea of the eye to an image pickup device for the observation and photographing of the corneal endothelial cell of the eye, a second slit plate provided with a slit narrower than that of the first slit plate, and a Z-alignment measuring light projecting optical system for projecting alignment measuring light through the slit of the second slit plate on the eye to measure the position of a main unit of the corneal endothelial cell photographing apparatus relative to the eye with respect to directions along the optical axis of the eye.

Corneal endothelial cell photographing apparatus

An apparatus for ascertaining the number of cells of an endothelium of a cornea of a subject's eye includes a display for displaying an image of cells of an endothelium of a photographed cornea, square meshes for partitioning the image of the cells displayed on the display by the unit area, and an enlarging device for enlarging and displaying an area partitioned by one of the square meshes on the display. The square meshes and the image are correlatively moved in a right or left direction on the display. An operator counts the number of the cells per unit area in an enlarged image, so that the operator ascertains the total number of the cells of the corneal endothelium.

Apparatus for imaging and diagnosing a cornea

An apparatus for observing and photographing a corneal endothelium includes an illumination optical system 28 for projecting each illumination light emitted by a light source 30 for observation and a light source 32 for photography onto a cornea C of a subject's eye E at an angle, an observing and photographing optical system 29 for receiving scattered light reflected by the cornea C with the endothelial layer and observing and photographing it, and an optical system 1 for observing the anterior segment of the eye E. The observing and photographing optical system 29 is provided with a sensor 47 for detecting an image of the endothelium in focus.

Apparatus for observing and photographing a corneal endothelium

An ophthalmologic apparatus includes an optical system for illuminating a subject's eye, an optical system for observing the eye illuminated by the illumination optical system, an alignment detecting system for detecting the alignment of the observation optical system with the eye, and a switchover circuit for switching over a reference allowable range to another range. The observation optical system can observe the eye at at least two different magnifications. The alignment detecting system includes a sensor for receiving reflection light reflected by the eye, a circuit for setting a reference allowable range, an arithmetic circuit for processing a signal output by the sensor and detecting an alignment condition, and a judgment circuit for judging whether the alignment condition detected by the arithmetic circuit is within the reference allowable range set by the range setting circuit.

Ophthalmologic apparatus

An apparatus for photographing a corneal endothelium of a patient's eye according to the invention includes an optical system for observing the anterior segment of the eye to align optical systems of the apparatus with the eye; an illumination optical system for projecting each illumination light emitted by a light source for observation and a light source for photography onto the cornea of the eye; an endothelium observing and photographing optical system for receiving reflected light from the corneal endothelium and observing and photographing it, the observing and photographing optical system including a reflected light receiving element for aligning the optical systems of the apparatus in the back and forth directions with the eye; display means for displaying images of the anterior segment and the corneal endothelium separately from each other; and image switching means for switching a displayed image from the anterior segment to the corneal endothelium and vice versa.

Apparatus for photographing a corneal endothelium

A noncontact type tonometer projects a fluid toward an eye-to-be-tested and obtains a measured value of eye pressure from a relation between transfigurations of the eye due to the fluid projection and the pressure projecting the fluid. A detecting circuit senses a pulse wave of the person-to-be-tested and a calculating circuit determines at least one of the maximum eye pressure value, minimum eye pressure value and average eye pressure value of the eye dependent on the maximum fluctuation width of the detected pulse wave, a fluctuating quantity of the detected pulse wave, and the measured eye pressure value. The calculation circuit determines the pulse wave fluctuating quantity at the time point when the eye pressure is measured. The pulse wave of the person may be measured at a position remote from the eye. The tonometer may also include a display for displaying the pulse wave and a display controller for displaying the time point when the eye pressure is measured. The displayed eye pressure overlaps the displayed pulse wave to illustrate the relation between the measured eye pressure value and the pulse wave fluctuation.

Noncontact type tonometer

A noncontact type tonometer projects a fluid toward an eye-to-be-tested and obtains a measured value of eye pressure from a relation between transfigurations of the eye due to the fluid projection and the pressure projecting of the fluid. A detecting circuit senses a pulse wave of the person-to-be-tested and a calculating circuit determines at least one of the maximum eye pressure value, minimum eye pressure value and average pressure value of the eye dependent on the maximum fluctuation width of the detected pulse wave, a fluctuating quantity of the detected pulse wave, and the measured eye pressure value. The calculation circuit determines the pulse wave fluctuating quantity at the time point when the eye pressure is measured. The pulse wave of the person may be measured at a position remote from the eye. The tonometer may also include a display for displaying the pulse wave and a display controller for displaying the time point when the eye pressure is measured. The displayed eye pressure overlaps the displayed pulse wave to illustrate the relation between the measured eye pressure value and the pulse wave fluctuation.

In a noncontact type tonometer including an air puff system for discharging fluid toward the cornea of an eye to be tested upon receipt of a projection signal and a pulse wave system for detecting the pulse of a patient which outputs an alternating voltage, the improvement comprising zero level detection system for detecting a zero level of the alternating voltage; and a timer which starts counting when the zero level has been detected by the zero detection systems and which outputs a projection signal to actuate the air puff system when the counted value has reached a preset time.

An ophthalmological instrument for the use of both corneal configuration and intraocular pressure measurement has alignment watching means for watching an alignment completion state upon receipt of an alignment completion signal which is output by alignment detecting means for detecting the alignment of an apparatus body with respect to an eye to be tested, corneal configuration measuring means for projecting a ring target mark onto the cornea of the eye and measuring a corneal configuration with reference to the ring target image, noncontact type intraocular pressure measuring means for discharging fluid toward the cornea in order to transfigure the cornea and measuring the intraocular pressure with reference to the amount of such transfiguration, and automatic executing means for executing the corneal configuration and intraocular pressure measurements in such a manner as that data of the ring target image is intaken in accordance with output of the alignment watching means in order to obtain data regarding the corneal configuration and thereafter checking whether the alignment completion state is maintained and if affirmative, automatically starting a fluid discharge onto the cornea.

Ophthalmological instrument

An alignment apparatus of a noncontact type tonometer has a target projecting system for projecting light emitted from a light emitting source to an eye to be tested along the axial line of a fluid discharging nozzle for discharging fluid and forming a target image on the eye, and an alignment light receiving optical system for receiving the target image along the axial line of the nozzle and forming an image of the target image on a light receiving sensor. The alignment apparatus of a noncontact type tonometer is characterized in that the light emitting source comprises a first and a second light emitting sources, the light receiving sensor comprises an area sensor, and the apparatus further has a control unit adapted to detect the positions of the target images of the first and second light emitting sources formed on the area sensor and to output an alignment completion signal when such detected positions are within a preset range on the area sensor.

Alignment apparatus of noncontact type tonometer

A noncontact type tonometer includes a fluid discharging device for discharging a fluid towards the cornea of an eye to be tested; an alignment detecting device for detecting an alignment between the axis of a fluid discharge of the fluid discharging device and the vertex of the cornea and for outputting an alignment signal; and a controlling device for determining whether or not the alignment has been completed upon receipt of the alignment signal from the alignment detecting device and outputting an alignment completion signal when the alignment has been completed. A fluid discharge of the fluid discharging device is automatically performed based on the alignment completion signal. The controlling device is provided with a monitoring device for monitoring the establishment of the alignment completion state for a predetermined time based on the alignment completion signal and outputting an action command signal for automatically performing the fluid discharge towards the fluid discharging device only when the alignment completion state has been maintained for the predetermined time.

Growing community of inventors

Tokyo, Japan

Kouji Nishio