JP3071693B2 - Eye refractive power measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a target projection optical system for projecting a target for fixation and fogging of an eye to be examined on the fundus, an observation optical system for observing an anterior segment of the eye, and a subject. An eye-refractive-power measuring device including a pattern light beam projection optical system for projecting a pattern light beam for measuring the refractive power of the optometry to the fundus of the eye to be inspected, and a light receiving optical system for receiving a light beam reflected from the fundus to a light receiving element. About.

[0002]

2. Description of the Related Art Conventionally, a ring-shaped pattern light beam for measuring the refractive power of an eye to be examined is projected onto the fundus of the eye by a pattern light beam projection optical system, and the reflected light beam reflected by the fundus is reflected by a light receiving optical system. 2. Description of the Related Art There is known an eye-refractive-power measuring device that measures a refractive power of an eye to be examined by causing a light receiving element to receive a pattern image based on the pattern image.

In such an eye refracting power measuring apparatus, as shown in FIG.
When the eye to be inspected is hyperopic, it forms a larger image than a normal eye when the subject's eye is hyperopic. When the eye to be examined is myopic, the image is formed smaller than when the eye is emmetropic.

Then, the peak position is detected at the image width center positions P1 and P2 of the pattern image 1 'formed on the light receiving element, and the pattern image 1 is detected based on the detected peak position.
The refractive power and the like are obtained by calculating the center distance L (distance between P1 and P2) of '.

[0005]

However, in the conventional eye refractive power measuring device, for example, as shown in FIG. 7, the center distance measuring position on the pattern light beam 1 projected on the fundus of the subject's eye is measured. When a blood vessel, a disease (scratch) 2 or the like is present above, a portion corresponding to the disease 2 is obtained as a peak position, and an image width center position P1 ′ shifted from the actual image width center position P1 is detected. Then, there is a problem that the measurement is erroneously performed as the astigmatic eye.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an eye refractive power measuring device capable of preventing erroneous measurement due to a blood vessel, a disease, or the like in the fundus.

[0007]

Means for Solving the Problems] To achieve the object, a first aspect of the present invention, pattern for projecting a pattern light beam for measuring the refractive power of the eye the fundus of the eye
And emission light beam projecting optical system, the eye refractive power measuring apparatus and a light receiving optical system for receiving the pattern reflected light beam reflected from the fundus to the light receiving element, the optical system and the light receiving optical system and the patterned light beam projection optics Is shared,
The point is that a deflecting member for deflecting the pattern light beam to a plurality of positions with respect to the optical axis of the pattern light beam projecting optical system and projecting the pattern light beam onto the fundus is inserted into a common portion of each optical system.

According to a second aspect of the present invention, the deflecting member is inserted at a position substantially conjugate with the pupil of the eye to be examined.

The invention according to a third aspect is characterized in that the deflecting member is rotatable around the optical axis of the pattern light beam projection optical system.

Further, the invention according to claim 4, the patterned light beam projecting optical system for projecting a pattern light beam for measuring the refractive power of the eye the fundus of the eye, the pattern reflected light beam reflected from the fundus in the eye refractive power measuring apparatus and a light receiving optical system for receiving the light-receiving element, provided in an optical path of the pattern light <br/> beam projection optics path for the optical axis
A first deflecting member for deflecting the turn light beam to a plurality of positions and projecting it on the fundus, and a second deflecting member provided in an optical path of the light receiving optical system and deflecting a pattern reflected light beam reflected from the fundus on the optical axis thereof. The gist of the present invention is that it includes a member.

The invention according to claim 5 is characterized in that the respective deflecting members are inserted at positions substantially conjugate with the pupil of the eye to be examined.

According to a sixth aspect of the present invention, the deflecting members are rotatable in synchronization with each optical axis.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an eye refractive power measuring device according to the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram of an optical system applied to the eye refractive power measuring device of the present invention. In FIG. 1, reference numeral 10 denotes an optotype projection optical system that projects an optotype onto the fundus Er in order to fixate and cloud the eye E, 20 denotes an observation optical system that observes the anterior segment Ef of the eye E, 30 Is the light-receiving element S
A scale projection optical system for projecting a pattern light beam for measuring the refracting power of the eye E to be inspected onto the fundus Er; a light receiving element S receiving a light beam reflected from the fundus Er This is a light receiving optical system.

The target projection optical system 10 includes a light source 11, a collimator lens 12, a target plate 13, a relay lens 14, a mirror 15, a relay lens 16, and a dichroic mirror 1.
7, a dichroic mirror 18 and an objective lens 19 are provided.

The visible light emitted from the light source 11 is converted into a parallel light beam by the collimator lens 12 and then collimated.
3 is transmitted. The target plate 13 is provided with a target for fixating and fogging the eye E to be examined. The target light flux passes through the relay lens 14 and is reflected by the mirror 15, is reflected by the dichroic mirror 17 through the relay lens 16, is guided to the main optical axis O 1 of the apparatus main body, passes through the dichroic mirror 18, and The light is guided to the eye E through the lens 19.

The light source 11, the collimator lens 12, and the optotype plate 13 are configured to be movable along the optical axis O2 of the optotype projection optical system 10 in order to fixate and fog the eye E to be examined. Has been

The observation optical system 20 includes a light source 21, an objective lens 19, a dichroic mirror 18, a relay lens 22,
An aperture 23, a mirror 24, a relay lens 25, a dichroic mirror 26, an imaging lens 27, and a light receiving element S are provided.

The light beam emitted from the light source 21 is
Is directly illuminated. The light beam reflected by the anterior segment Ef is reflected by the dichroic mirror 18 through the objective lens 19, passes through the relay lens 22, passes through the diaphragm 23 at the same time, and is reflected by the mirror 24.
The light passes through the relay lens 25 and the dichroic mirror 26 and is imaged on the light receiving element S by the imaging lens 27.

The scale projection optical system 30 includes a light source 31, a collimator lens 32 provided with an aiming scale, a relay lens 33, a dichroic mirror 18, and a relay lens 2.
2, a stop 23, a mirror 24, a relay lens 25, a dichroic mirror 26, an imaging lens 27, and a light receiving element S.

The light beam emitted from the light source 31 is converted into an aiming scale light beam (parallel light beam) when passing through the collimator lens 32, and then passes through the relay lens 33, the dichroic mirror 18, the relay lens 22, the diaphragm 23, and the mirror 2.
Then, the light is reflected by the imaging lens 27 and is imaged on the light receiving element S by the imaging lens 27 through the relay lens 25 and the dichroic mirror 26.

For the light receiving element S, for example, a two-dimensional area CCD or the like is used.
The anterior segment image guided by 0 is displayed, and an image based on the aiming scale is displayed. The examiner performs an alignment operation in the vertical and horizontal directions between the subject's eye E and the apparatus main body so that the anterior eye image displayed on the monitor approaches the aiming scale image. In addition, an alignment operation in the front-back direction is performed.
When the refractive power is measured after the completion of the alignment operation, the light sources 21 and 31 are turned off, or a shutter or the like is provided in an optical path from the dichroic mirror 18 to the dichroic mirror 26 to prevent the light receiving element S from receiving light.

The pattern light beam projection optical system 40 includes a light source 4
1. Collimator lens 42, conical prism 43, ring index plate 44, relay lens 45, mirror 46, relay lens 47, perforated prism 48, optical axis deflecting prism 49 as a deflecting member, dichroic mirror 17, dichroic mirror 18, objective The lens 19 is provided. The light source 41 and the ring index plate 44 are optically conjugate, and the ring index plate 44 and the pupil Ep of the eye E are optically conjugated.

The light beam emitted from the light source 41 is converted into a parallel light beam by a collimator lens 42,
3, the light is guided to the ring index plate 44, passes through the ring-shaped pattern portion formed on the ring index plate 44, and becomes a pattern light beam. After passing through the relay lens 45, the pattern light flux is reflected by the mirror 46, passes through the relay lens 47, and is transmitted through the perforated prism 48 to the main optical axis O 1.
After passing through the dichroic mirrors 17 and 18 while being deflected obliquely by the optical axis deflecting prism 49 and deviated from the main optical axis O1, the objective lens 19
To form an image on the fundus Er.

The optical axis deflecting prism 49 is rotated at a high speed around the main optical axis O1 (see arrow). The pattern light beam projected onto the fundus Er by the high speed rotation is, as shown in FIG. Orbit around the axis O1 in an eccentric state.

The light receiving optical system 50 includes an objective lens 19, dichroic mirrors 18 and 17, an optical axis deflecting prism 49,
The hole 48a of the perforated prism 48, the relay lens 51,
It has a mirror 52, a relay lens 53, a mirror 54, a focusing lens 55, a mirror 56, a dichroic mirror 26, an imaging lens 27, and a light receiving element S.

The focusing lens 55 includes a light source 41, a collimator lens 42, a conical prism 43, and a ring index plate 44.
Are movable along the optical axes O3 and O4 of the respective optical systems 40 and 50.

The reflected light flux guided to the fundus Er by the pattern light beam projection optical system 40 and reflected by the fundus Er is:
The dichroic mirror 1 is focused on the objective lens 19
8 and 17 are guided to the optical axis deflecting prism 49, and when transmitted through the optical axis deflecting prism 49 according to the principle of light beam reversal, the holes of the apertured prism 48 are opened from the same portion centered on the main optical axis O1. To the hole 48a and pass through the hole 48a.

The pattern reflected light beam passing through the hole 48a passes through the relay lens 51, is reflected by the mirror 52, passes through the relay lens 53, is reflected by the mirror 54, passes through the focusing lens 55, and passes through the mirror 56. Further, the light is reflected by the dichroic mirror 26, and a pattern image is formed on the light receiving element S by the imaging lens 27.

In the above configuration, first, each light source 1
The eyes E, 21 and 31 are turned on to fixate the eye E, and the alignment operation between the eye E and the apparatus body is performed. When the alignment is completed, the light sources 11, 21 and 31 are turned off and the light source 41 is turned off. Light.

The illumination light beam emitted from the light source 41 passes through the ring index plate 44 to become a ring-shaped pattern light beam, and is guided to the optical axis deflection prism 49.

The optical axis deflecting prism 49 is rotated at a high speed the main optical axis O1 by a high-speed rotary unit (not shown) as the axis (see FIG. 2) while deflected from the main optical axis O1 in the pattern image 44 'on the fundus Er Is imaged.

[0033] The reflected light flux reflected by the fundus Er is guided to the optical axis deflecting prism 49, as shown in FIG. 3, as the pattern image 44 "around the main optical axis O1 again the principle of the light beam reversing An image is formed on the light receiving element S.

The examiner operates a measurement execution switch (not shown) to store the pattern image 44 ″ on the light receiving element S based on the pattern image 44 ′ formed at an arbitrary position in the circle projected on the fundus Er and stored in a frame memory or the like. Are stored in a plurality of storage media.

For example, as shown in FIGS. 4A to 4F, a ring center O1 'is located on the fundus Er from the optical axis O1.
Corresponding to the displaced pattern image 44 '
When stored in a storage medium as the pattern image 44 ″ above,
In the states shown in FIGS. 4A, 4D, 4E, and 4F, the detected peak positions Q1 and Q2 coincide with the actual image width center positions. ) And (C), the peak positions Q3 and Q4 due to the influence of the disease 2.
Are shifted from the actual center position of the image width.

By averaging these peak positions Q1, Q3, and Q4 with the number of times of storage, the peak position Q1 'approaching the actual image width center position can be calculated as shown in the graph of FIG. The eye refractive power can be measured by calculating the distance between the center of the width based on the position information of the peak position Q1 'and the peak position Q2 (the measuring method is well-known and will be omitted).

In the first embodiment, the optical axis deflecting prism 49 is used as the deflecting member. For example, as shown in FIG. 5A, two prisms 49a and 49b which can be independently and synchronously rotated are provided. Rotary prism 49
′ As a deflecting member, and, as shown in FIG. 5B, for example, as shown in FIG. 5B, while rotating one prism 49b about the optical axis O1 as an axis, the entirety of the rotary prism 49 ′ is optical axis O1.
May be rotated about the axis.

At this time, the deviation of the output angle with respect to the optical axis O1 can be adjusted and changed by the independent rotation amount of the prisms 49a and 49b. It can be.

As described above, according to the embodiment of the present invention, the range that can be affected by the disease 2 on the trajectory of the pattern image 44 'is very small compared to the range that is not affected. That is, in the case of the disease 2 illustrated in FIG.
Since it can be said that the other range is the same as that of the normal eye on the locus of the range shown in (B) and (C), the portion which is not affected by the disease 2 as the number of times of storing the peak position in the storage medium is increased. The possibility of capturing fundus information is high, and by averaging the measurement results of the distance between the width centers, it is possible to obtain measurement results that are so reliable that deviation due to the presence of the disease 2 can be ignored.

At this time, the location of the disease 2 or the like on the fundus Er differs for each subject. Therefore, simply projecting the pattern image 44 ′ at the shifted position (deflected position) may cause the disease 2 or the like to exist at the shifted position.
There is a risk that the measurement result will be erroneous measurement. However, in the present invention, since the pattern image is rotated and recorded on the recording medium a plurality of times, the possibility of capturing the pattern image 44 ″ affected by the disease 2 is reduced, and the reliability of the measurement result is improved. can do.

The pattern image 44 'is projected at a position shifted from the optical axis O1, but since the eye E and the apparatus main body maintain a constant relationship by performing an alignment operation, the measured data It does not impair the reliability of.

In the above embodiment, the optical axis deflecting prism 49 includes the pattern light beam projection optical system 40 and the light receiving optical system 5.
However, the present invention is not limited to this. For example, one optical axis deflecting prism of the same type is disposed in a non-common part of each optical system, and both optical axis deflecting prisms are inserted. If the rotation angles are always the same, the same operation and effect can be obtained.

[0043]

As described in the foregoing, in the eye refractive power measurement apparatus of the present invention, a plurality of position pattern light beam with respect to the optical axis in the optical path is shared between the receiving optical system patterned light beam projection optics By providing a deflecting member for deflecting the image to the fundus and projecting it on the fundus, it is possible to prevent erroneous measurement due to blood vessels or diseases of the fundus.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an optical system, illustrating an eye refractive power measuring device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state of a pattern image formed on the fundus of the eye.

FIG. 3 is an explanatory diagram showing a relationship between a pattern image formed on a light receiving element and a peak position.

FIGS. 4A to 4F are explanatory diagrams showing a relationship between an example in which a pattern image formed on the fundus is arbitrarily stored and a peak position corresponding to the pattern image.

5A and 5B are diagrams illustrating a modification of the deflecting member, wherein FIG. 5A is an explanatory diagram of a rotary prism in a light beam non-deflecting state, and FIG. 5B is an explanatory diagram of a rotary prism in a light beam deflecting state.

FIG. 6 is an explanatory diagram showing a relationship between a pattern image formed on a light receiving element by a conventional eye refractive power measuring device and a peak position.

FIG. 7 is an explanatory diagram showing a relationship with a peak position when a disease is present on a pattern image formed on a light receiving element by a conventional eye refractive power measuring device.

[Explanation of symbols]

 E: eye to be examined Er: fundus oculi Ef: anterior segment S: light receiving element O1: optical axis 10: target projection optical system 20: observation optical system 40: pattern light beam projection optical system 49: optical axis deflecting prism (deflecting member) 50 ... Reception optical system

Claims (6)

(57) [Claims] And 1. A patterned light beam projecting optical system for projecting a pattern <br/> light beam for measuring the refractive power of the eye the fundus of the eye, to receive the pattern reflected light beam reflected from the fundus to the light receiving element An eye refractive power measurement device comprising a light receiving optical system, wherein the pattern light beam projection optical system and the light receiving optical system share a part of an optical system, and a pattern is formed with respect to an optical axis of the light beam projection optical system. An eye-refractive-power measuring apparatus, wherein a deflecting member for deflecting a light beam to a plurality of positions and projecting the light beam on a fundus is inserted into a common portion of each of the optical systems. 2. An eye refractive power measuring apparatus according to claim 1, wherein said deflecting member is inserted at a position substantially conjugate with a pupil of an eye to be examined. 3. An eye refractive power measuring apparatus according to claim 1, wherein said deflecting member is rotatable about an optical axis of said pattern light beam projection optical system. 4. A patterned light beam projecting optical system for projecting a pattern <br/> light beam for measuring the refractive power of the eye the fundus of the eye, to receive the pattern reflected light beam reflected from the fundus to the light receiving element An eye-refractive-power measuring device including a light-receiving optical system, wherein the first deflection unit is provided in an optical path of the pattern light beam projection optical system and deflects the pattern light beam to a plurality of positions with respect to the optical axis and projects the pattern light beam onto the fundus An eye, comprising: a member; and a second deflecting member provided in an optical path of the light receiving optical system and deflecting a pattern reflected light beam reflected from the fundus on an optical axis thereof. Refractive power measuring device. 5. The eye refractive power measuring device according to claim 4, wherein each of the deflection members is inserted at a position substantially conjugate with a pupil of the eye to be examined. 6. The deflecting member according to claim 5, wherein each of the deflecting members is rotatable synchronously around each optical axis.
Refractive power measurement apparatus of the eye.