JPH10118024A - Objective ophthalmic refractive force measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily perform objective measurement of ophthalmic refractive force even when there exists turbid in an eye to be examined by moving a position of an incident optical axis of a projected light flux of a projecting optical system to the surface of a pupil in the eye to be examined without changing the position of the incident optical axis of a reflected light flux to a face of detection of a measuring optical system. SOLUTION: A parallel plane panel 8 can be inclined to an optical axis by rotating it around the first rotational axis as a center being orthogonal to the optical axis of a light flux for measurement and the light flux for measurement from a polalized beam splitter 12 is moved in parallel in the inclined direction of the parallel plane panel 8 by the amt. corresponding to the angle of inclination of the parallel plane panel 8 and in addition, it is moved in the peripheral direction around the second rotational axis by the amt. corresponding to the angle of rotation of an image rotator 6. In addition, the angle of inclination of the parallel plane panel 8 and the angle of rotation of the image rotator 6 are appropriately controlled and the light flux for measurement is displaced in parallel to the light axis by arbitrary amt. and direction and is passed through a cold mirror 4 and is guided into an arbitrary position in the pupil of the eye to be examined and is transmitted to the eyeground of the eye to be examined 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eye-refractive-power measuring apparatus capable of objectively measuring the refractive power of an eye to be inspected, and particularly to an eye refractive power measurement apparatus which is easily used even when local opacity or scars are present in the crystalline lens of the eye. The present invention relates to an objective eye refractive power measuring device capable of measuring the eye refractive power.

[0002]

2. Description of the Related Art Conventionally, as a kind of objective refractive power measuring method of the eye, it has been described in JP-A-55-160538, JP-A-57-165735 and JP-B-5-56734. As described above, there is known an image analysis method in which a light beam for measurement is projected on a fundus of an eye to be inspected, and an eye refractive power is measured by observing movement of a light beam reflected by the fundus.

By the way, in the conventional radiographic method, generally, the central axis of the light beam for measurement is aligned with the center of the pupil of the eye to be examined.
The measurement is performed by irradiating the central part of the pupil with a measuring light beam.

However, according to the conventional radiographic method, if the lens of the subject's eye is opaque or the cornea is damaged, the reflected light flux from the fundus cannot be sufficiently obtained, and the measurement error increases. In some cases, measurement became impossible. In particular, the present inventor has studied and found that in the conventional radiographic method, in general, since the center axis of the light beam for measurement is aligned with the center of the pupil of the eye to be inspected, opacity and scratches are present at the center of the pupil. In some cases, it became clear that the adverse effect on the measurement was large.

Further, the present inventor has studied that the conventional refraction method of irradiating the central portion of the pupil with the measuring light beam has a problem that the measured refractive power at the center of the pupil is different from the refractive power at the peripheral portion of the pupil. There is also a problem that a measurement difference easily occurs between a subjective eye refractive power measurement value viewed through the entire pupil.

[0006]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a method for performing a radiographic examination even when the eye to be inspected has opacity or scratches. It is an object of the present invention to provide an objective eye-refractive-power measuring apparatus having an improved structure capable of easily performing the objective eye-refractive-power measurement by the method described above.

It is another object of the present invention to provide an objective eye refractive power measuring apparatus which can advantageously reduce the difference between the subjective eye refractive power measurement value.

[0008]

In order to solve such a problem, the present inventor has conducted a number of experiments and examined the results. In the force measurement, when there is a partial opacity or scar etc. in the pupil of the eye to be examined,
It has been found that it is extremely effective to appropriately shift the central axis of the light beam for measurement from the center of the pupil of the subject's eye in accordance with the position of the turbidity or the like, and thus it has been found that high-precision measurement is possible. Thus, based on such knowledge, the present invention has been completed.

The invention according to claim 1 is characterized in that a projection optical system for projecting a measurement light beam onto the fundus of the eye to be inspected, and a reflection of the light beam projected by the projection optical system from the fundus. In an objective eye refractive power measuring apparatus having a measuring optical system for detecting a light beam, the position of the optical axis of the projection light beam incident on the pupil surface in the eye to be inspected in the projection optical system with respect to a detection surface in the measuring optical system There is provided a light beam moving means for moving the reflected light beam without changing the position of the incident optical axis.

In the eye-refractive-power measuring device having the structure according to the first aspect of the present invention, the incident position of the projection light beam on the eye to be examined is appropriately changed according to the opacity position of the eye to be examined. For example, by positioning the opacity position at the corner of the measurement target range in the subject's eye or out of the measurement target range, the adverse effects of turbidity or the like can be reduced or avoided, and the level required for measurement can be reduced. Thus, it is possible to easily secure the reflected light flux, and thus it is possible to advantageously measure the eye refractive power and the like by a radiographic method or the like. When measuring the refractive power of the eye by a contrast method or the like that does not use the entire pupil, it is extremely effective to change the incident position of the projection light beam on the eye to be examined in the measurement of the eye to be examined having partial opacity or the like. Yes, sufficient measurement accuracy can be obtained.

For this reason, for example, when measuring the refractive power of the eye by a radiographic method or the like that does not use the entire pupil, a first aspect of the present invention is described.
By using an eye refractive power measurement device having a structure according to the invention described in the above, if the incident position of the projection light beam to the eye to be examined is changed and the eye refractive power is measured at a plurality of locations, the opacity and the like from the measurement result It is also possible to know the presence or absence, position, etc., and in actual measurement, it is possible to easily measure the eye refractive power without being conscious of such turbidity, etc., and extremely good operation Character can be realized.

At this time, since the position of the incident optical axis of the reflected light beam with respect to the detection surface of the measuring optical system is stably secured without shifting, when changing the incident position of the projected light beam to the eye to be examined, There is no need to particularly consider correction of measured values, and excellent operability and stable measurement accuracy are exhibited.

Further, in the eye-refractive-power measuring device having the structure according to the first aspect of the present invention, the incident position of the projection light beam with respect to the eye to be inspected is appropriately changed so that the eye refractive power and the like at a plurality of positions in the pupil can be measured. Measurement can be easily performed. Therefore, for example, if the measurement values at a plurality of points are considered together, the improvement of the measurement accuracy can be advantageously achieved, and the subjective eye refractive power measurement can be performed. A reduction in the measurement difference from the value can also be advantageously achieved. In addition, in such an eye refractive power measuring device, the position, size, degree, and the like of cloudiness or damage in the eye to be examined are determined based on the measured values by examining the measured values at a plurality of locations together. It is also possible to perform an ophthalmic examination other than the measurement of the refractive power of the eye.

That is, by changing the incident position of the projection light beam on the pupil surface of the eye to be examined in the projection optical system by using the eye refractive power measuring device according to the first aspect, the range of the pupil of the eye to be examined is changed. It is also possible to easily carry out a measurement method for eye refractive power and the like, which is characterized by performing measurements at a plurality of points in the above and comprehensively judging the measurement results, thereby improving the measurement accuracy. Such effects are achieved.

The invention described in claim 2 is the first invention.
In the objective type eye refractive power measuring device described in the above, an observation optical system for photographing the pupil surface of the eye to be examined and displaying the photographed image on a monitor is provided.

In the objective type eye refractive power measuring apparatus having the structure according to the second aspect of the present invention, the examiner can directly visually recognize the pupil surface of the eye to be examined at the time of examination. It is possible to visually confirm turbidity and the like on the pupil surface, and thereby operability such as changing the incident position of the projection light beam on the pupil surface can be improved.

The invention described in claim 3 is the first invention.
Or in the objective eye refractive power measurement apparatus according to 2, wherein a fixation target projection optical system for fixing the eye to be examined is provided,
Features.

In the objective type eye refractive power measuring device having the structure according to the third aspect of the present invention, since the pupil position of the eye to be examined can be advantageously fixed at the time of examination, the pupil of the projection light beam is used. The operability such as the change of the incident position on the surface is improved, and the measurement accuracy can be improved.

The invention described in claim 4 is the first invention.
In the objective eye refractive power measuring apparatus according to any one of (1) to (3), an optical path of a projection light beam in the projection optical system and an optical path of a reflected light beam in the measurement optical system are at least partially coaxial with each other, A plane-parallel plate disposed on the coaxial optical path and spaced apart from each other on the coaxial optical path and rotatable about a first rotation axis perpendicular to the optical axis of the optical path; It is characterized by being constituted by an image rotator rotatable around a second rotation axis parallel to the axis.

In the objective type eye refractive power measuring apparatus having the structure according to the fourth aspect of the present invention, the amount of deviation of the optical axis of the projection light beam is set according to the rotation angle of the plane parallel plate. At the same time, the direction of deviation of the optical axis of the projection light beam is set according to the rotation angle of the image rotator. Therefore, by appropriately adjusting the rotation angles of the parallel plane plate and the image rotator, the incident position of the projection light beam can be arbitrarily determined in the pupil of the eye to be inspected. The means can be advantageously realized with a very simple configuration and easy adjusting operability. In addition, as a rotation drive mechanism of the parallel plane plate or the image rotator, for example, a drive mechanism using a pulse motor is advantageously employed.

The invention described in claim 5 is the first invention.
In the objective eye refractive power measuring apparatus according to any one of (1) to (3), an optical path of a projection light beam in the projection optical system and an optical path of a reflected light beam in the measurement optical system are at least partially coaxial with each other, The light beam moving means are disposed on the coaxial light path at a distance from each other, around a third rotation axis and a fourth rotation axis that are perpendicular to and not parallel to the optical axis of the optical path, respectively. It is characterized by comprising a set of rotatable parallel flat plates.

In the objective type eye refractive power measuring apparatus having the structure according to the fifth aspect of the present invention, the objective eye refractive power measuring apparatus is configured such that the inside of the pupil of the subject's eye is adjusted according to each rotation angle of the set of parallel plane plates. The amount of deviation of the optical axis of the projection light beam on coordinate axes orthogonal to each other is set. Therefore, by appropriately adjusting the rotation angle of each parallel plane plate, the incident position of the projection light beam can be arbitrarily determined in the pupil of the eye to be inspected. It can be advantageously implemented with a very simple configuration and easy adjustment operability. It should be noted that a driving mechanism using a pulse motor, for example, is advantageously employed also as a rotation driving mechanism for the set of parallel flat plates.

[0023] The invention described in claim 6 is the first invention.
4. In the objective eye refractive power measuring device according to any one of claims 3 to 3, wherein the light beam moving means mechanically displaces the projection optical system and the measurement optical system relative to the eye to be examined. It is characterized by being constituted by a displacement mechanism.

In the objective type eye refractive power measuring device having the structure according to the sixth aspect of the present invention, the light beam moving means can be advantageously realized without changing the configuration of each optical system. In particular, when realizing the light beam moving means,
Since there is no need to arrange a special optical member on the projection optical path or secure a space for disposing the optical member on the projection optical path, the optical path can be shortened, and the amount of reflected light flux can be reduced. Can be advantageously secured.

The invention described in claim 7 is the same as the claim 6.
In the objective type eye refractive power measuring device described in the above, using a four-node chain mechanism in which four links are connected by one fixed axis and three moving axes, the four links are connected to the projection optical system Along the surface orthogonal to each optical path of the measuring optical system, the movable optical system is arranged so as to be movable around the fixed axis, and two of the four links have one end connected by the fixed axis. A first moving means for moving one of the swing links about the fixed axis, and a second moving means for moving the other swing link about the fixed axis. By allowing the projection optical system and the measurement optical system to be supported by any one of the two movable links whose both ends are connected by the moving shaft among the links,
It is characterized in that the mechanical displacement mechanism is configured.

In the objective type eye refractive power measuring device having the structure according to the seventh aspect of the present invention, a machine for displacing the projection optical system and the measuring optical system integrally by using a link mechanism. Since the dynamic displacement mechanism is configured,
The projection light beam can be displaced with extremely high accuracy while fixing the incident position of the reflected light beam on the inspection surface, thereby advantageously ensuring measurement accuracy. Moreover, since the position of incidence of the projection light beam on the subject's eye is changed according to the displacement of the projection optical system,
There is also an advantage that the change direction and the change amount of the incident position can be easily grasped and the operability is excellent.

In particular, by using the link mechanism,
A mechanical displacement mechanism that can move and position the projection light beam to any position within the range of the pupil, and that can support, move, and position the projection optical system and the measurement optical system with high positional accuracy, It can be realized very advantageously with a simple structure.

The invention described in claim 8 is the same as the invention described in claim 7.
The objective eye refractive power measurement device according to the above, wherein the first moving means and the second moving means, a power transmission mechanism using a cam that is rotated and positioned by an electric motor, characterized in that, I do.

In the objective type eye refractive power measuring apparatus having the structure according to the eighth aspect of the present invention, each of the oscillating links is controlled by controlling the rotation angle of the cam using a pulse motor or the like. Can be set with high precision, and the deviation of the projection optical system and the measurement optical system can be set with high accuracy, whereby the measurement accuracy can be further improved and stabilized.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIG. 1 shows a configuration diagram of an objective eye refractive power measuring apparatus based on a radiographic method as a first embodiment of the present invention. In FIG. Shows the system. Then, in the observation optical system 100, the reticle 30 located at a position substantially conjugate with the cornea of the eye 2 to be examined.
Is illuminated by the rear light source 28 and the cold mirror 4
The light passes through the half mirror 32 and the observation lens 34, is further reflected by the reflection mirror 36, and forms an image plane 38 of the CCD camera.
It can be focused on. On the other hand, the illumination light 5
2 is reflected by the cornea of the eye 2 to be examined, further reflected by the cold mirror 4, passes through the same optical path as described above,
An image is formed on the image plane 38 of the CCD camera. The examiner moves the apparatus up and down, left and right, and back and forth while looking at a monitor (not shown) on which the above-mentioned reticle 30 image and the corneal image of the subject's eye 2 are projected, so that the focus is clear. That is, the positioning is performed.

In the fixation target projection optical system 200 in such an objective eye refractive power measuring apparatus, the light source 40
Illuminates the fixation target 42, while the light flux from the fixation target 42 passes through the lens 44 and the variable stop 46, is reflected by the mirror 48, and then passes through the objective lens 50, The lens 44 and the objective lens 50 convert the light into a substantially parallel light flux. The light is further reflected by the half mirror 32 and the cold mirror 4 to reach the retina of the eye 2 to be examined. It is configured to fixate on 42.

In the fixation target projection system 200, the fixation target 42 can be moved in the optical axis direction by a driving device (not shown). And such a drive is
An eye is controlled by an output of an arithmetic circuit (not shown) so that the subject's eye 2 can move the fixation target 42 to a predetermined position where fixation can be performed without adjustment. ,
It constitutes an automatic fog device.

Further, in the projection optical system 300, the inclination angle of the first lens 22 and the slit-shaped light beam is set to be different from each other by two or more along the traveling direction of the light from the measurement light source 20. A chopper disk 24 having a slit is provided, and the chopper disk 24 is rotated by a motor 26. Further, the chopper disk 24 emitted from the measurement light source 20
A polarizing beam splitter 12 is provided on the optical path of the measurement light beam having a slit shape, so that the measurement light beam is applied to the cornea of the eye 2 from the front. On the optical path of the measurement light beam between the polarizing beam splitter 12 and the eye 2, a second lens 10 that makes the measurement light source 20 substantially conjugate with the corneal surface of the eye 2 is provided.
A parallel flat plate 8 and an image rotator 6 are fixedly provided and located between the second lens 10 and the subject's eye 2 at a predetermined distance from each other. This allows
A light beam from the measurement light source 20 passes through the second lens 10, passes through the parallel plane plate 8 and the image rotator 6, and is guided to the pupil of the eye 2 to be inspected.

Here, the plane-parallel plate 8 is rotated about a first rotation axis orthogonal to the optical axis of the measuring light beam, thereby being inclined with respect to the optical axis. . The rotation and positioning of the parallel plane plate 8 about the first rotation axis are performed by a pulse motor (not shown).
Is controlled with high precision with respect to the optical axis.

On the other hand, the image rotator 6 is a known one having a trapezoidal block shape. As shown in FIG. 2, the image rotator 6 is accommodated in a rotating frame 54 and is parallel to the optical axis of the measuring light beam. And is rotatably supported around the second rotation axis. Further, the rotating frame 54 for accommodating and holding the image rotator 6 is connected to the pulse motor 6 via gear mechanisms 56 and 58.
By means of 0, it is adapted to be rotationally displaced around a second rotation axis.

As a result, the measuring light flux transmitted from the polarizing beam splitter 12 through the second lens 10 is
The parallel flat plate 8 allows the parallel flat plate 8 to be translated in the tilt direction of the parallel flat plate 8 by an amount corresponding to the tilt angle of the parallel flat plate 8 and the image rotator 6.
Accordingly, the image rotator 6 can be moved in the circumferential direction around the second rotation axis by an amount corresponding to the rotation angle of the image rotator 6. Therefore, by appropriately adjusting the inclination angle of the parallel plane plate 8 and the rotation angle of the image rotator 6, the measurement light beam can be displaced in an arbitrary direction in an arbitrary direction with respect to the optical axis thereof. Therefore, the measurement light beam can be transmitted through the cold mirror 4, guided to an arbitrary position in the pupil of the eye 2, and transmitted to the fundus of the eye 2. .

As is apparent from this, in the present embodiment, the light beam moving means includes the parallel plane plate 8 and the image rotator 6. Further, in such a light beam means, it is possible to move the measuring light beam guided to the pupil of the eye 2 continuously on the pupil. For example, if the tilting speed before and after the parallel plane plate 8 and the rotation speed of the image rotator 6 are synchronized, the projection light flux moves in parallel by the parallel plane plate 8 and the projection light flux passing therethrough is changed by the rotation of the image rotator 6. As a result, it is spirally moved and guided to the pupil of the eye to be inspected 2, and the inclination angle of the parallel plane plate 8 is changed stepwise, and the image rotator 6 is moved each time. If the rotation is made around the second rotation axis, the projection light beam is concentrically moved and guided to the pupil of the subject's eye 2, or the image rotator 6 is rotated stepwise around the second rotation axis. At the same time, if the plane-parallel plate 8 is tilted each time, the projected light beam is moved radially and guided to the pupil of the eye 2 to be inspected.

Further, in the measuring optical system 400, of the scanning light beam (measuring light beam) projected into the pupil of the eye 2 to be inspected, the light beam reflected by the fundus (reflected light beam) is reflected by the cold mirror 4 and the image rotator. 6, after passing through the parallel plane plate 8, the second lens 10, and the polarizing beam splitter 12, the light is condensed by the imaging lens 14. A stop 16 having a circular opening centered on the optical axis is provided behind the imaging lens 14, and further behind the stop 16.
The photoelectric converters 18 are fixedly provided, respectively. The aperture 16 is substantially conjugate to the fundus of the eye 2 to be examined, and the light receiving surface of the photoelectric converter 18 as a detection surface is
Are respectively arranged on the optical axis so as to be substantially conjugated to the cornea.

In short, in the present embodiment, between the eye to be inspected 2 and the polarizing beam splitter 12, the measuring light beam in the projection optical system 300 and the reflected light beam in the measuring optical system 400 are guided in coaxial optical paths. It is becoming. Thus, when the optical axis of the reflected light beam in the projection optical system 300 is displaced by the parallel plane plate 8 and the image rotator 6 between the parallel plane plate 8 and the subject's eye 2, the reflection in the measurement optical system 400 The optical axis of the light beam is displaced in the opposite direction by the image rotator 6 and the parallel flat plate 8 by an amount corresponding to the displacement amount of the measurement light beam, and is guided on the optical axis of the second lens 10. Therefore, the reflected light beam is reflected on the light receiving surface 1 of the measurement optical system 400 regardless of the displacement amount of the measurement light beam.
8 is always illuminated on a fixed central axis.

As well known, the light receiving surface of the photoelectric converter 18 in the measuring optical system 400 is
As shown in FIG. 3, the photoelectric conversion element 18 which is a light receiving element
a, 18b, 18c and 18d are respectively disposed off the optical axis. And a pair of photoelectric conversion elements 18a,
Reference numeral 18c denotes a plane including one of the directions of one measurement meridian, that is, one of the directions in which the slit light beam scans the eye 2 (Y direction) and the optical axis, passes through the center of each, and is substantially symmetric with respect to the optical axis. And another pair of photoelectric conversion elements 18b, 18d.
Is the other of the direction of the measurement meridian orthogonal to the direction of the measurement meridian, that is, the other direction (X
Direction) and a plane including the optical axis pass through the respective centers, and are arranged symmetrically with respect to the optical axis on lines perpendicular to the optical axis. Then, the photoelectric conversion elements 18 forming these pairs
The target eye refractive power information is calculated based on the output signals from a, 18c and 18b, 18d. The calculation method is well known, for example, Japanese Patent Application Laid-Open No. Sho 62-5147. Since it has been clarified in the publication of Japanese Patent Application Laid-Open Publication No. H10-163, it is omitted here.

When the eye refractive power of the eye to be examined is measured using the objective type eye refractive power measuring apparatus having such a structure, the fixation target projection optical system 2
In a state where the fixation target 42 of 00 is fixed, the examiner projects the projection light beam to the pupil of the eye 2 by the projection optical system 300 while observing the monitor of the observation optical system 100 as necessary. The reflected light flux from the fundus is measured by the measuring optical system 4.
This is performed by receiving light with the photoelectric converter 18 of 00.

In this objective eye refractive power measuring apparatus, the inclination angle of the parallel flat plate 8 and the rotation angle of the image rotator 6 arranged on the optical path of the projected light beam and the reflected light beam are changed. In addition, the projection position of the projection light beam onto the eye 2 can be arbitrarily changed within the range of the pupil.

Therefore, even when partial turbidity or the like is present in the pupil of the subject's eye 2, for example, it is necessary to appropriately move the projection position of the projection light beam as shown in FIG. As a result, the effect of turbidity can be very easily and quickly reduced or avoided, and the eye refractive power can be measured.

Alternatively, it is easy to measure the refractive power of the eye at a plurality of positions in the pupil of the eye 2 to be examined, and by comprehensively judging the measured values,
It is also possible to improve the measurement accuracy of the eye refractive power. The measured values of the eye refractive power at a plurality of positions can be comprehensively processed, for example, by calculating their average value or weighted average value, or by statistically judging them.

Next, FIG. 4 schematically shows, as a second embodiment, another specific example of the light beam moving means which can be employed in the objective eye refractive power measuring device as the first embodiment. Is shown in

That is, in the present embodiment, a parallel plane plate 9 is provided instead of the image rotator 6 constituting the light beam moving means in the first embodiment, and one light beam is provided on the optical path of the measurement light beam. Set of parallel plane plates 8, 9
Are disposed at a predetermined distance from each other. Further, these parallel plane plates 8 and 9 are rotatable around a third rotation axis and a fourth rotation axis which are perpendicular to the optical axis of the optical path of the measurement light flux and are not parallel to each other. In particular, in the present embodiment, the third rotation axis and the fourth rotation axis are perpendicular to each other in the optical axis direction, in other words, such that the orthogonal axis is at a twist position separated in the optical axis direction. , Is set.

Thus, the light beam from the measuring light source passes through the pair of parallel flat plates 8 and 9 and is guided to the pupil of the eye 2 to be examined. By rotating the parallel plane plates 8 and 9 about the third rotation axis or the fourth rotation axis and tilting them with respect to the optical axis, the optical axis of the measurement light beam is adjusted to the respective parallel plane plates 8 and 9. 9 is displaced in each direction perpendicular to the optical axis and perpendicular to each other by an amount corresponding to the inclination angle of 9. The rotation and positioning of these parallel flat plates 8, 9 around the third and fourth rotation axes are performed by a pulse motor (not shown).

Therefore, by appropriately adjusting the respective inclination angles of the pair of parallel flat plates 8 and 9, the measuring light beam is displaced in an arbitrary direction in an arbitrary direction with respect to its optical axis. Thus, the measurement light beam can be guided to an arbitrary position in the pupil of the eye 2 and projected on the fundus of the eye 2. Moreover, in the light beam moving means including the pair of parallel plane plates 8 and 9 as described above, the optical axis of the light beam reflected from the fundus of the eye to be examined also has an amount corresponding to the displacement amount of the measurement light beam. The displacement is corrected in the opposite direction by the pair of parallel flat plates 8 and 9.

Therefore, even when the light beam moving means is constituted by using a pair of parallel plane plates 8 and 9 as in the present embodiment, the same effects as in the first embodiment can be effectively exhibited. It can be done.

FIGS. 5 and 6 show a third embodiment of an objective eye refractive power measuring device in which the light beam moving means is constituted by a mechanical displacement mechanism. In the present embodiment, members and parts having the same structure as the first embodiment are denoted by the same reference numerals as those of the first embodiment in the drawings, respectively.
Detailed description thereof will be omitted.

That is, in the objective eye refractive power measuring apparatus of the present embodiment, the projection optical system 300 and the measurement optical system 40
0 are integrally formed, and the movable optical system 500 as a whole is
It has been. Then, the movable optical system 500 moves in a direction orthogonal to the visual axis of the eye 2 to be examined, in other words, the projection optical system 3.
In the direction orthogonal to the optical axis of the measuring light beam 00 and the reflected light beam of the measuring optical system 400, the entirety and the whole can be moved by a mechanical displacement mechanism using a link mechanism.

As shown in FIG. 6, the mechanical displacement mechanism comprises two upper and lower links 75 and 76 extending substantially in the horizontal direction, and two left and right links 71 and 72 extending substantially in the vertical direction. Are connected to each other by one fixed shaft 64 and three moving shafts 66, 68, 70, thereby providing a four-node chain mechanism that is a square link mechanism as a whole. The four-bar linkage has a lower rod 76 and a right link 72 each having one end connected to each other by a fixed shaft 64 and a support rod fixed to a housing 77 of the eye-refractive-power measuring device. 79, the fixed shaft 6
Pivotally pivoted about 4 so that
Fixed shaft 64 and first to third moving shafts 66, 68, 70
Based on the relative rotation of the links 75, 76, 71, 72 around the respective links 75, 76, 71, 72.
Is the measurement light beam of the projection optical system 300 and the measurement optical system 4.
In a plane orthogonal to the optical axis in the reflected light flux of 00,
It can be displaced. As is apparent from this, in the present embodiment, the lower link 76 and the right link 72 are swing links, and the upper link 75
And the left link 71 are movable links.

The upper link 75 is connected to the first moving shaft 66.
Is extended further outward in the horizontal direction than the connecting portion with the left link 71, and the movable optical system 5
An optical component mounting member 62 that integrally supports the optical component 00 is formed. Accordingly, by displacing the link mechanism, the movable optical system 50 supported by the optical component mounting member 62 is displaced with respect to the subject's eye 2, whereby the optical axis of the projection light beam in the projection optical system 300 and the measurement optical system System 400
Is displaced with respect to the eye to be examined at the same time.

Next, a drive mechanism for displacing the link mechanism will be described. First, in such a link mechanism, the right link 72 is connected to the housing 77 by a first coil spring 74, and the first coil spring 74 causes the fixed shaft 64 to be connected to the right link 72.
A clockwise bias is exerted around. Also,
The lower link 76 is connected to the housing 77 by a second coil spring 78, and a counterclockwise urging force about the fixed shaft 64 is applied to the lower link 76 by the second coil spring 78. Has been affected.

Further, a ball bearing 80 is mounted on the second moving shaft 68 connecting one end of the right link 72 and one end of the upper link 75.
The outer peripheral surface of the flat cam formed by the eccentric disk 84 is brought into contact with the outer peripheral surface of the eccentric disk 84, and is maintained in a contact state based on the urging force of the first coil spring 74. The eccentric disk 84 is rotationally driven and positioned around an eccentric rotation center axis 83 by a first pulse motor 82.

The left link 71 has a third moving axis 7
0, a transmission disk 88 is pivotally supported so as to be rotatable around a central axis, and a cam surface whose axial end face is inclined in the circumferential direction with respect to the outer peripheral surface of the transmission disk 88. The cylinder 92 that forms the end surface cam is brought into contact with the cam surface, and is maintained in a contact state based on the urging force of the second coil spring 78. The column 92 is rotated and positioned around a central axis by a second pulse motor 90.

In such a link mechanism, the eccentric disk 8 by the first and second pulse motors 82 and 90 is used.
4 and the rotation of the cylinder 92, the eccentric disk 84 and the cylinder 92 are rotated about the fixed shaft 64 by an amount corresponding to the rotation angle of the eccentric disk 84 and the cylinder 92. In other words, these eccentric disks 84 and The rotation position of the link mechanism is determined based on the rotation angle of the cylinder 92.

Accordingly, in the mechanical displacement mechanism using such a link mechanism, the eccentric disk 84 and the column 9
The movable optical system 500 supported by the link mechanism is displaced and positioned by displacing and positioning the link mechanism via the two cam mechanisms constituted by the second and third cam mechanisms. Of the subject's eye 2 can be guided to an arbitrary position in the pupil of the subject. In addition, in such a mechanical displacement mechanism, since the measuring optical system 400 is also moved together with the projection optical system 300, the reflected light beam is stabilized with respect to the light receiving surface of the photoelectric converter 18 in the measuring optical system 400. It is led.

Therefore, by configuring the light beam moving means using the mechanical displacement mechanism as in the present embodiment, the same effects as those of the first and second embodiments can be effectively exhibited. It is.

In the mechanical displacement mechanism using such a link mechanism, the eccentric disk 8 required for displacing the measuring light beam in a desired amount and direction is required.
The rotation amount of 4 and the cylinder 92 can be easily obtained by calculation.

Specifically, for example, as shown in FIG. 7, each of the links 75, 7 constituting the link mechanism is used.
6, 71, 72, that is, the distance between the fixed shaft 64 and each of the moving shafts 66, 68, 70 is 25 mm, and when such a link mechanism forms a square, It is assumed that the center of the pupil coincides with the optical axis of the movable optical system 500, that is, the optical axis of the measurement light beam. In addition,
Under this condition, the optical axis T3 of the movable optical system 500 is set at a position separated from the first moving axis 66 by 42.5 mm in the horizontal direction and 25 mm in the vertical direction.

From this state, it is necessary to displace the optical axis of the measuring light beam by 2.5 mm in the horizontal direction (left direction in the figure) and 2.5 mm in the vertical direction (down direction in the figure). The amount of movement of the moving shaft 68 by the eccentric disk 84 and the amount of movement of the moving shaft 70 by the cylinder 92 can be obtained, for example, according to the following method.

That is, as shown in FIG. 7, in the present embodiment, the movable optical system 500 is fixed to the optical component mounting member 62 formed by extending the upper link 75. The center of the movement axis 66: T1 and the second movement axis 6
By directly observing that the shape of the triangle obtained by connecting the center of 8: T2 and the optical axis of the measurement light beam: T3 is invariable, the displacement amount of the optical axis of the target measurement light beam: T3 is: It can be easily calculated by a computer or the like based on the geometric theory.

The calculation results obtained in this way are shown in FIG.
Shown in As shown in FIG. 8, the optical axis of the measuring light beam is set to 2.5 mm in the horizontal direction and 2.5 mm in the vertical direction.
In order to displace the second moving shaft 68 only by 1.64 mm in the horizontal direction (left direction in the drawing) and the third moving shaft 70
Can be moved vertically (downward in the figure) by 0.9 mm. Therefore, the horizontal and vertical movement amounts are calculated from the target measurement light beam movement position, and the cam of the eccentric disk 84 corresponding to the rotation angle of the first pulse motor 82 in the horizontal direction. In the vertical direction, the second pulse motor 90
The cam diagram is determined by the amount of displacement of the cam surface of the cylinder 92 corresponding to the rotation angle of.

Although some embodiments of the present invention have been described in detail above, the present invention should not be construed as being limited by the specific description of such embodiments.

For example, in each of the above embodiments, the present invention is applied to an objective type eye refractive power measuring apparatus by a radiographic method. It is needless to say that the present invention can be similarly applied to an objective eye refractive power measuring device using a method or the like.

Further, the specific structure of the light beam moving means in the present invention is not limited to the above embodiment, and various other optical or mechanical optical axis displacement mechanisms can be adopted. .

Further, for example, instead of the mechanical displacement mechanism using the link mechanism in the third embodiment, a movable support board that integrally supports the movable optical system 500 is orthogonal to the optical axis of the measurement light beam. It is also possible to construct the mechanical displacement mechanism using a moving means capable of reciprocatingly driving and positioning by an arbitrary distance in two different directions, preferably in the X direction and the Y direction orthogonal to each other.

Further, in the third embodiment, the inclination angle caused by the rotational displacement of the measuring light beam around the optical axis due to the displacement of the movable optical system 500 is obtained, and the measured inclination angle is calculated with respect to the measured cylinder axis angle and the like. It is also possible to add a correction for eliminating a measurement error caused by such a tilt.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements, and the like can be made, and unless such embodiments depart from the spirit of the present invention.
Both are included in the scope of the present invention,
Needless to say.

[0072]

As is clear from the above description, in the objective type eye refractive power measuring device having the structure according to the first to eighth aspects of the present invention, any of the objective type eye refractive power measuring devices within the range of the pupil can be used. Since the incident position of the measurement light beam can be easily moved, even if there is a cloudy part in the pupil, for example, by appropriately shifting the incident position of the measurement light beam, a sufficient level of reflection for measurement can be obtained. The light beam can be obtained advantageously, and the refractive power of the eye to be inspected can be measured easily and with high accuracy.

In particular, in the objective eye refractive power measuring device, since the incident position of the measuring light beam in the pupil can be moved, the refraction of the eye to be examined can be effectively utilized by using only a part of the pupil. It is possible to measure force etc. with high accuracy, and it is possible to measure by irradiating the measurement light flux at multiple points in the pupil, so it was obtained for refractive power measurement By using the information, it is also possible to know the presence or absence, the position, the degree, and the like of an abnormality such as turbidity in the eye to be examined, if necessary.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing an objective eye refractive power measuring apparatus as a first embodiment of the present invention.

FIG. 2 is a schematic view showing a main structure of a light beam moving means used in the objective eye refractive power measuring device shown in FIG.

FIG. 3 is an explanatory diagram showing a light receiving surface of a photoelectric converter 18 constituting a measuring optical system in the objective eye refractive power measuring device shown in FIG.

FIG. 4 is a schematic view of a main part showing another embodiment of a light beam moving means that can be used in the objective eye refractive power measuring device shown in FIG. 1;

FIG. 5 is a configuration diagram schematically showing an objective eye refractive power measuring device as a third embodiment of the present invention.

FIG. 6 is a schematic diagram showing a main structure of a light beam moving means used in the objective eye refractive power measuring device shown in FIG.

FIG. 7 is an explanatory diagram for specifically explaining a method of setting a movement amount of a projection light beam in the light beam moving means shown in FIG. 6;

FIG. 8 is a model diagram showing a calculation result of a movement amount of a projection light beam in the light beam moving means shown in FIG. 7;

[Explanation of symbols]

 2 Eye to be inspected 6 Image rotator 8, 9 Parallel plane plate 18 Photoelectric converter 20 Light source for measurement 62 Optical component mounting material 64 Fixed axis 66, 68, 70 Moving axis 71, 72, 75, 76 Link 74, 78 Coil spring 84 Eccentricity Disk 92 Column 100 Observation optical system 200 Fixation target projection optical system 300 Projection optical system 400 Measurement optical system 500 Movable optical system

Claims (8)

[Claims] 1. An objective refraction system comprising: a projection optical system for projecting a measurement light beam onto the fundus of an eye to be inspected; and a measurement optical system for detecting a reflected light beam from the fundus of the light beam projected by the projection optical system. In the force measurement device, the position of the incident optical axis of the projection light beam on the pupil surface in the eye to be inspected in the projection optical system, without changing the position of the incident optical axis of the reflected light beam with respect to the detection surface in the measurement optical system And an objective-type eye-refractive-power measuring device provided with a light beam moving means for moving. 2. The objective optical refractometer according to claim 1, further comprising an observation optical system for photographing the pupil surface of the eye to be examined and displaying the photographed image on a monitor. 3. The objective eye refractometer according to claim 1, further comprising a fixation target projection optical system for fixing the eye to be examined. 4. An optical path of a projection light beam in the projection optical system and an optical path of a reflected light beam in the measurement optical system are at least partially coaxial with each other, and the light beam moving means is the coaxial light. A plane-parallel plate disposed on the path apart from each other and rotatable about a first rotation axis perpendicular to the optical axis of the optical path; and rotated about a second rotation axis parallel to the optical axis of the optical path. 4. The objective eye refractive power measuring device according to claim 1, wherein the objective eye refractive power measuring device is constituted by a possible image rotator. 5. An optical path of a projection light beam in the projection optical system and an optical path of a reflected light beam in the measurement optical system are at least partially coaxial with each other, and the light beam moving means is coaxial light. A set of parallel plane plates, spaced apart from each other on the path and rotatable about a third rotation axis and a fourth rotation axis, each perpendicular to and not parallel to the optical axis of the optical path, An objective eye refractive power measuring device according to any one of claims 1 to 3, which is configured. 6. The light beam moving means according to claim 1, wherein said projection optical system and said measuring optical system are mechanically displaced integrally with respect to said subject's eye. An objective eye refractive power measuring device according to any one of the above. 7. A four-node chain mechanism in which four links are connected by one fixed axis and three moving axes, and the four links are provided in each optical path of the projection optical system and the measurement optical system. Along with being arranged movably about the fixed axis on a plane orthogonal to the plane,
A first moving means for moving one of the four links about the fixed shaft, and a second moving means for moving one of the four links at one end by the fixed shaft; A second moving means for moving the link about the fixed axis is provided, and the projection optical system and the projection optical system are connected to each other by one of two movable links of which the both ends are connected by the moving axis among the four links. 7. The objective eye refractive power measuring apparatus according to claim 6, wherein the mechanical displacement mechanism is configured by supporting a measuring optical system. 8. The objective type according to claim 7, wherein the first moving means and the second moving means are each constituted by a transmission mechanism using a cam rotated and positioned by an electric motor. Eye refractive power measuring device.