Kabushiki Kaisha Topcon

Nec Corporation

Nippon Electric Co., Ltd.

Mitsubishi Oil Co., Ltd.

Honda Motor Co., Ltd.

Nippon Sheet Glass Company, Limited

Hiroshi Iijima

Akinari Takagi

Kouji Nishio

Kiyokazu Okamoto

Masaru Sato

Norio Tanaka

Hiroyuki Ohtsuka

Hideaki Oshima

Yukio Miyamoto

Kunihiko Hara

Yoshihiko Hanamura

Kazuhito Tate

Mineki Hayafuji

Kenjiro Katsuragi

Kazuhiro Yanagida

Yasuhisa Ishikura

Kunihiko Moriya

Goro Muroga

Yasushi Sano

Kenjirou Katsuragi

Yoshikazu Nakamura

Akiyoshi Inoue

Masahiro Higashi

Hiroshi Kuribayashi

An ophthalmologic apparatus is disclosed, in which even in the case where the range of lateral relative movement of a trestle is limited with respect to a base, the measurement can be continued without enlarging the space occupied by the apparatus body and without imposing an extra burden on the testee. The apparatus comprises a trestle ( ) mounted on a base ( ) and laterally movable relative to the base ( ) and has a limited range, and a measuring head portion ( ) mounted on the trestle ( ) and automatically laterally moved relative to the trestle ( ) with respect to a reference position (H ). In the case where the trestle ( ) moves rightward or leftward and reaches a movement limit position O , O , the reference position (H ) of the measuring head portion ( ) with respect to the trestle ( ) is shifted in the direction in which the trestle ( ) moves.

Ophthalmologic apparatus

In an ophthalmologic apparatus which can start a measurement or a photographing operation with respect to an eye to be examined by suitably making an automatic alignment with a cornea of the eye as a center, When a diseased eye is to be measured, slight reflected light (e.g., cornea scattering light) except for reflected light from a vertex of the cornea of the eye is interrupted by an XY alignment detecting stop even when this slight reflected light is detected by a position detecting sensor. Accordingly, since no slight reflected light is almost incident to a light quantity detecting sensor, the XY alignment light quantity detecting circuit does not output an alignment completion signal to a control circuit. Thus, the control circuit performs a control operation such that the measurement or the photographing operation with respect to the eye is not performed.

A noncontact tonometer has a control circuit which actuates a puffing means to apply an air pulse through a puffing nozzle to the cornea of a subject's eye only when it is found from alignment positional information provided by an XY-alignment detecting circuit that the position of an intraocular pressure measuring unit relative to the cornea is in a predetermined range narrower than and in an allowable alignment range when the alignment of the intraocular pressure measuring unit is readjusted after the measurement of the thickness of a specific section of the cornea.

Noncontact tonometer for measuring intraocular pressure

A noncontact tonometer is provided which is capable of intercepting out-of-axis light of an index beam of light and performing precise alignment. The noncontact tonometer includes an index projecting optical system for projecting an index frontally onto a subject's eye (E) through a nozzle (12) through which gas is also is sprayed upon the eye (E). The index projecting optical system has a projection lens (27) and a diaphragm (23) disposed at a position conjugated to an end surface (F) of the nozzle (12) on the side of the projection lens (27). The diaphragm (23) intercepts rays of light traveling out of an optical axis, and enables precise alignment.

Noncontact tonometer

Disclosed herein is an ophthalmic instrument comprising: an optical measuring section (101) for housing an optical system that measures characteristics of an object eye; an alignment detecting optical system (17') for optically detecting an offset quantity in alignment between the optical measuring section and the object eye; drive units (102 and 103) for moving the optical measuring section (101) vertically, laterally, and longitudinally on the basis of the offset quantity detected by the alignment detecting system (17'); and a control circuit (51) for transmitting a signal which instructs start of measurement to the optical measuring section (101) when the alignment detecting system detects that the object eye has been moved within a measurable area. Prior to the start of measurement the control circuit (51) continues to move the optical measuring section (101) for only a predetermined time so that the object eye (optical axis Oe of the object eye) is moved within a drive target area smaller than the measurable area and also included in the measurable area.

Ophthalmic instrument

An ophthalmologic apparatus is provided which comprises a slit light projecting optical system (60) for projecting a slit beam of light from an oblique direction onto the cornea (C) of a subject's eye, a light receiving optical system (70) for receiving light reflected by the cornea (C), a corneal thickness measuring circuit (74) for measuring the thickness of the cornea from information on the received light of the light receiving optical system (70), an index light projecting optical system (90) for projecting from an oblique direction onto the cornea (C) an index beam of light having a larger width than the slit beam, and a line sensor (72) for receiving the index beam reflected by the cornea (C).

A stopper knob (108) is provided on the side surface of a base (101). If a joy stick (107) is tilted forward lowering the stopper knob (108), a platform frame (109) advances, and the main body of an instrument can be roughly aligned with a subject eye to be tested. If the alignment is completed, the stopper knob (108) is released. In the ophthalmic instrument of the present invention, automatic alignment which performs precise alignment on the subject eye is not started by only releasing the stopper knob (108). The ophthalmic instrument is provided with a microswitch (111). When the platform frame (109) is pulled on a tester's side by the joy stick (operating stick) (107) and the microswitch (111) engages with a protruding portion (112) fixed to the base (101), automatic alignment is started.

An ophthalmological instrument is provided in which optical members can be satisfactorily cleaned, the times for cleaning can be reduced and reliability of measuring accuracy can be improved. An alignment between a cornea (C) of an eye (E) to be tested and an instrument body is detected by projecting an alignment detecting light toward the cornea (C) through alignment detecting optical systems (30, 40) and receiving a luminous flux reflected on the cornea (C) through a light receiving sensor (45). A working distance between the cornea (C) and the instrument body is detected projecting a working distance detecting light toward the cornea (C) through working distance detecting optical systems (50, 60) and receiving a luminous flux reflected on the cornea (C) by a light receiving sensor (63). Part of optical paths of the alignment detecting optical systems (30, 40) and the working distance detecting optical systems (50, 60) are not used in common. Dirt stuck to optical members arranged in part of the optical paths which are used in common is detected in accordance with signals from the light receiving sensors (45, 63).

Ophthalmological instrument

An alignment luminous flux is projected toward the cornea of an eye-to-be-detected by an alignment light projecting optical system. The alignment luminous flux reflected by the cornea is imaged on two light receiving means by an alignment light imaging optical system one of which light receiving means is disposed on the front side of an light collecting position adjacent to the cornea when the cornea is in a correct working distance and the other of which is on the back side.

Ophthalmological instrument with improved alignment mechanism

In order to detect an alignment state while watching an index image, illumination light is first projected onto an anterior segment of a subject's eye (E) from LEDs (21), and then light emitted by another LED (31) is guided to a cornea (C) through an alignment light projecting optical system (30). The light emitted by the LEDs (21, 31) and reflected by the subject's eye (E) is imaged on a CCD camera (26) through an image-formation optical system (20). An index image (SP) and an anterior segment image (E') which are of the reflection light guided to the CCD camera (26) are displayed on a screen (28). The index image (SP) is received by a sensor (46). Based on information about received light obtained by the sensor (46), a comparator (47) detects information about alignment of the subject's eye (E) with an instrument body. According to a detection result obtained by the comparator (47), a display state of the display (28) is changed, so that an operator judges that a desired state of alignment is nearing.

Ophthalmologic instrument

A noncontact type tonometer is provided which is capable of easily detecting whether optical members of the tonometer are stained with dirt or not, and easily finding which one of the optical members is stained. In the noncontact type tonometer, alignment light emitted by an alignment light source is guided to a subject's eye through an alignment light projecting optical system. Part of the alignment light reflected by the eye does not pass through a discharging nozzle and is received by a first light receiving sensor of a first alignment detecting optical system. On the other hand, the other part of the alignment light reflected by the eye passes through the discharging nozzle and is received by a second light receiving sensor of a second alignment detecting optical system. Stains on the optical members are found by a measuring device by which a quantity level of reflected alignment light received by each of the first and second sensors is detected and compared with each other. If the optical members are not stains, pulsed air is discharged from the nozzle toward the eye.

Noncontact type tonometer

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 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.

A three-phase induction motor is subjected to countermeasure for the rotor and the stator in order to remove two harmonic components of the orders causing a torque ripple, among a plurality of harmonic components included in a magnetic flux generated in an air gap between a stator core and a rotor core. In the three-phase induction motor, conductor grooves of the rotor core are skewed by an electrical angle of 2.pi./n where n is the order of one of the harmonic components to be removed. In the stator, the number of slots (N) is selected so that an equation N=l.times.m.times.q is satisfied, where l=the number of poles, m=the number of phase, and q is a non integer number representing the number of slots per pole per phase, and the stator winding pitch is determined according to the order of another harmonic component to be removed.

Three-phase induction motor

A three-phase induction motor includes winding slots and a stator winding. The number of winding slots per pole per phase is a noninteger. The stator winding is a three-phase balanced winding. A pitch s of the winding satisfies s=(r-t)/r or s=r/(r+t) (where t is an odd number and r is the order of a harmonic wave to be suppressed).

Growing community of inventors

Tokyo, Japan

Hiroshi Iijima