JPH11146864A - Localization instrument for ophthalmologic instrument and localization instrument for ophthalmophotograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To photograph a clear eyeground image by permitting an optical photographing axis to coincide with the center of a pupil when the gaze of an eye to be inspected is largely moved in a direction except a front direction so as to photograph the target part of the eye ground by means of shifting it to the neighborhood of a photographing visual field center in eye ground photographing. SOLUTION: An eyeground photographing optical system Sb is moved in its optical axis direction in a state where the optical axis 4 of the eye ground photographing optical system Sb is made to coincide with the vertex of the eye to be inspected E by alignment so as to adjust an operation distance. Then, the optical axis 4 of the eye ground photographing optical system Sb is guided so as to coincide with the center of the pupil based on the pupil center of a front eye part image which is received by a front eye part observation optical system Sd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating position determining device for automatically determining an operating position of an ophthalmologic apparatus or a fundus photographing apparatus.

[0002]

2. Description of the Related Art A fundus camera (fundus photographing apparatus) is one of the ophthalmologic apparatuses. The fundus camera has an illumination optical system and a photographing optical system, projects illumination light to the fundus through a pupil, and photographs the fundus through the pupil. I do. The illumination optical axis coincides with the photographing optical axis. Since the fundus photography performs illumination and photography through the pupil in this way, it is important to position the photographing optical system and the subject's eye. However, manual operation requires complicated operations and requires skill. In addition, since it takes time, the subject is forced to be nervous for a long time until the imaging.

[0003] In order to eliminate such complicated operations and reduce the time required for photographing, a fundus photographing apparatus provided with an operation position determining device for automatically performing the above-mentioned alignment has been proposed (for example, Japanese Patent Application Laid-Open No. HEI 9-110572). 8-275921). This uses the reflected light from the vertex of the subject's eye of the parallel light projected from the front to the subject's eye as an index to automatically perform alignment in a plane perpendicular to the imaging optical axis, and then applies slit light obliquely forward to the subject's eye. The working distance is automatically adjusted in the direction of the photographing optical axis by projecting and using the reflected light of the slit light from the vertex of the eye to be inspected as an index. When an image of the eye to be examined is directed to the front direction and photographed by this device, a fundus image centered on the gazing point (fovea) of the fundus is photographed.

[0004]

In the above-described operation position determining device, no particular problem occurs when the eye axis is facing the front. However, in fundus photographing, the target part of the fundus may be moved to the vicinity of the center of the photographing field of view by photographing the gaze of the eye to be examined with a fixation target. When the line of sight is guided and the eye axis points in a direction other than the front, the vertex of the eye to be examined and the center of the pupil do not coincide with each other in a plane orthogonal to the imaging optical axis. As described above, the fundus imaging apparatus irradiates the fundus with illumination light through the pupil, and performs imaging of the fundus through the pupil.
If the photographing optical axis does not coincide with the center of the pupil, illumination and photographing are blocked by the iris. In the above-described operation position determination device, since the photographing optical axis is aligned with the vertex of the eye to be inspected, if the eye axis of the eye to be examined is directed to a direction other than the front, the fundus cannot be clearly photographed.

As a method for solving this problem, for example,
A method of quantitatively correcting the deviation between the vertex of the eye to be examined and the center of the pupil according to the angle at which the gaze is guided and fixed can be considered. In other words, the line of sight of the eye to be inspected is usually fixed at a predetermined angle by a fixation lamp, but the imaging optical axis is moved from the vertex position of the eye to be inspected by a correction amount predetermined for each fixation lamp. Move it. This method is effective when photographing a predetermined position of the fundus as in a medical examination. However, it cannot cope with a case where it is desired to change the photographing position to a position other than the predetermined position. Further, it is not possible to cope with the case where the subject is oblique. This is because, in the case of strabismus, a point shifted from the fovea becomes a gazing point, so that the direction of the eye axis cannot be predicted from the fixation lamp.

As another method for solving the above-mentioned problem, for example, a method of aligning with the center of the pupil of the anterior eye image instead of the vertex of the eye to be examined is also conceivable. This method is effective when the subject's eye axis slightly fluctuates from the front direction. However, if the eye axis largely swings from the frontal direction, the vertex position of the eye to be inspected is greatly displaced from the alignment position. As a result, the reflected light of the slit light for adjusting the working distance from the subject's eye does not return to the light receiving element for detecting the working distance, and the working distance cannot be detected.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention automatically determines an appropriate operating position even if the line of sight is greatly swung at an arbitrary angle and the subject is oblique, and It is an object of the present invention to provide an operating position determining apparatus for an ophthalmologic apparatus capable of clearly capturing and observing an image and an operating position determining apparatus for a fundus photographing apparatus capable of capturing a clear fundus image.

[0008]

In order to solve the above-mentioned problems, an operating position determining apparatus for an ophthalmologic apparatus according to the present invention comprises:
What is claimed is: 1. An operating position determining apparatus for an ophthalmologic apparatus having, as a main optical system, an optical system for photographing and / or observing a predetermined portion of an eye to be inspected, and an alignment index projecting optical system for projecting alignment index light onto an eye spherical surface of the eye. And an anterior segment observation optical system that receives an anterior segment image of the subject's eye and receives the reflected light from the spherical surface of the alignment index light as an ocular surface reflection image. Alignment means for guiding the main optical system so that the optical axis of the main optical system coincides with the vertex of the eye to be inspected based on the position of the observed spherical reflection image of the eye, and the optical axis of the main optical system by the alignment means. The main optical system is so arranged that the main optical system can be received at a predetermined position so that the reflected light from the vertex of the eye to be examined of the working distance detection index light projected from the oblique front to the eye to be examined can be received in a state where the vertex coincides with the vertex of the eye to be examined. Moved in the optical axis direction Based on the pupil center of the anterior ocular segment image received by the anterior ocular segment observation optical system, the optical axis of which coincides with the vertex of the eye to be examined by the alignment unit. And an alignment correcting means for guiding the main optical system guided so that the optical axis coincides with the center of the pupil (claim 1). The main optical system may be an optical system having both a photographing function and an observation function, or may be an optical system having only one of the functions.

According to another aspect of the present invention, there is provided an operation position determining apparatus for a fundus photographing apparatus, which illuminates a fundus of an eye to be examined with illumination light, and photographs the fundus based on the illumination light. An operating position determining apparatus for a fundus photographing apparatus having a fundus photographing optical system, the apparatus including an alignment index projecting optical system that projects an alignment index light onto the spherical surface of the eye to be inspected, and receiving an anterior eye image of the eye to be inspected. Along with the anterior ocular segment observation optical system that receives the reflected light of the alignment index light from the ocular spherical surface as an ocular spherical reflection image, and based on the ocular spherical surface reflection image position observed by the anterior ocular segment observation optical system, Alignment means for guiding the fundus imaging optical system so that the optical axis of the fundus imaging optical system coincides with the vertex of the eye to be inspected; and the alignment means aligning the optical axis of the fundus imaging optical system with the vertex of the eye to be inspected. Moving the fundus imaging optical system in the direction of its optical axis so that the reflected light from the vertex of the subject's eye of the working distance detection index light projected obliquely to the subject's eye can be received at a predetermined position. Based on the working distance adjusting means for adjusting the working distance, and the center of the pupil of the anterior ocular segment image received by the anterior ocular segment observation optical system, such that the optical axis coincides with the vertex of the eye to be examined by the alignment means. And an alignment correcting means for guiding the fundus photographing optical system guided to the center of the pupil so that the optical axis thereof coincides with the center of the pupil (claim 2).

[0010] In the operating position determining apparatus for an ophthalmic apparatus or the operating position determining apparatus for a fundus photographing apparatus, the apparatus further comprises a fixation lamp for changing and fixing the line of sight of the eye to be examined.
The fixation lamp may change the line of sight of the eye to be examined, so that the position of the fundus photographed by the fundus photographing optical system can be changed.

With this configuration, the optical axis of the main optical system or the fundus photographing optical system is temporarily determined based on the position of the reflection image (Purkinje image) of the alignment index light reflected from the spherical surface of the eye.
Adjusted to match the vertex of the eye to be inspected (alignment adjustment)
Is done.

After the alignment is adjusted, the working distance is adjusted based on the working distance detecting index light.
This adjustment is performed in a state where the optical axis of the main optical system or the fundus photographing optical system coincides with the vertex of the eye to be inspected. Therefore, the adjustment can be performed based on the reflected light from the vertex of the eye to be inspected.

When the working distance is adjusted, the optical axis of the main optical system or the fundus photographing optical system that coincides with the vertex of the eye to be examined is adjusted (alignment correction) so that it coincides with the center position of the pupil. You.

Thus, the ophthalmologic apparatus can accurately detect the position of the pupil, and in particular, when photographing and observing a part deeper than the iris of the eye to be examined through the pupil, the part is blocked by the iris. You can shoot and observe clearly without any need. In addition, it is possible to cope with a wide range of movement of the eye to be examined, and it is possible to clearly photograph and observe even if the angle of the eye to be examined cannot be predicted as in the case of a strabismus. Also,
An ophthalmologic apparatus that automatically determines an operating position in the order of alignment adjustment, working distance adjustment, and alignment correction can be configured.

The fundus photographing apparatus can project illumination light onto the fundus without being blocked by the iris, and can also reflect light reflected from the fundus into the fundus photographing optical system without being blocked by the iris. Therefore, a clear fundus image can be taken. In addition, it is possible to cope with a wide range of movement of the eye to be examined, and a clear fundus image can be obtained even if the angle of the eye to be examined cannot be predicted as in the case of a strabismus. Further, it becomes possible to configure a fundus photographing apparatus that automatically determines an operation position in the order of alignment adjustment, working distance adjustment, and alignment correction.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram showing a schematic configuration of a fundus photographing apparatus 1 which is one of the ophthalmologic apparatuses. The operating position determining device for the fundus photographing device is one of the operating position determining devices for the ophthalmologic apparatus. The operating position determining device according to an embodiment of the present invention is applied to the fundus photographing device 1. . First, a schematic configuration of the fundus imaging apparatus 1 will be described with reference to FIG.

The fundus photographing apparatus 1 mainly has a mirror body 3 on which various optical systems are disposed, and a drive mechanism (XY-axis drive mechanism 50, Z-axis drive mechanism 52) for driving the mirror body 3.
And a control circuit 45 for processing signals from the optical system and controlling the driving mechanism.

On the mirror body 3, there are mainly an illumination optical system Sa, a fundus photographing optical system Sb, an alignment target projection optical system Sc,
Anterior eye observation optical system Sd, working distance index projection optical system Se,
A working distance detecting optical system Sf and a focusing index projecting optical system Sg are provided. The fundus photographing optical system Sb also corresponds to a main optical system described in the claims.

The illumination optical system Sa is an optical system for illuminating the fundus of the eye E, and includes a strobe discharge tube 11, condenser lenses 12, 13, a circular slit 14, a mirror 15, condenser lenses 18, 20, and It comprises a perforated mirror 6. The visible light emitted from the strobe discharge tube 11 is focused by the condenser lenses 12 and 13 at the position of the circular slit 14, passes through the circular slit 14, is reflected by the mirror 15, and folds the optical path on the illumination optical axis 16. Bendable. Further, this visible light travels on the illumination optical axis 16, and the condenser lens 18,
The light is focused near the perforated mirror 6 through the half mirror 19 and the condenser lens 20 of the focusing index projection optical system G described later, and an image of the circular slit is formed on the perforated mirror 6. Further, this visible light is reflected by a perforated mirror 6, and the photographing optical axis 4
The optical path is bent upward, passes through the objective lens 5 of the fundus imaging optical system Sb, focuses near the pupil from the vertex position of the eye E, and irradiates the retina surface of the fundus.

The fundus photographing optical system Sb is an optical system for photographing the fundus based on the illumination light of the illumination optical system Sa, and includes an objective lens 5, a focus lens 7, a relay lens 8, and a television camera (color television for photographing the fundus). Camera 10). These constituent members of the fundus imaging optical system Sb are disposed on the imaging optical axis 4. The fundus image passes through the objective lens 5, the perforated mirror 6 of the illumination optical system Sa, the focus lens 7 and the relay lens 8, and
The image is formed on the CCD light receiving surface 9 and photographed. The image signal output from the television camera 10 is input to the control circuit 45.

The alignment target projection optical system Sc is an optical system for projecting the alignment target light onto the spherical surface F of the eye E to be inspected.
It comprises a mirror 22, a condenser lens 23, a mirror 25 and a concave lens 26. The concave lens 26 is for performing a correction for canceling out the strong power of the objective lens 5, and a lens having a strong canceling out power is used. The infrared light, which is the alignment index light emitted from the alignment light emitting diode 21a, is reflected by the mirror 22, and the optical path is bent on the alignment index optical axis 27a. The alignment index light passes through the condenser lens 23 and the half mirror 24 of the anterior ocular segment observation optical system Sd, is reflected by the mirror 25, and bends the optical path on the imaging optical axis 4. Further, the alignment index light is supplied to the concave lens 26 and the fundus photographing optical system Sb.
And is projected as parallel light toward the eye sphere F of the eye E to be examined. The concave lens 26 and the mirror 25 are retracted from the photographing optical axis 4 when the fundus is illuminated by the illumination optical system Sa and when the fundus is photographed by the fundus photographing optical system Sb, as described later. Also,
A plurality of fixation lamps (not shown) are incorporated in the alignment index projection optical system Sc. These fixation lamps are used to fix the line of sight of the eye E by causing the subject to look closely. Thus, the line of sight of the eye E can be fixed in the front direction or in a direction rotated by a predetermined angle from the front direction.

The anterior eye observation optical system Sd is an optical system for receiving the reflected light of the alignment index light from the eye spherical surface F of the eye E and receiving the anterior eye image of the eye E.
It comprises a half mirror 24, an anterior segment observation lens 28, a television camera 30, and an anterior segment illumination light source 21b.
The reflected light of the alignment index light from the ocular sphere F passes through the objective lens 5 and the concave lens 26, is reflected by the mirror 25, and has its optical path bent on the alignment index optical axis 27a. Further, the reflected light is reflected by the half mirror 24, and the optical path is bent on the anterior ocular segment observation optical axis 27b. The reflected light that has passed through the anterior eye observation lens 28 reaches the CCD light receiving surface 29 of the television camera 30 and forms an image. Further, an anterior eye image formed as a bright and dark image having a different brightness level due to the pupil and iris of the eye E to be examined is also input to the television camera 30 along the same route as the reflected light of the alignment index light. The anterior segment illumination light source 21b is provided to illuminate the eye E with infrared light so that an anterior segment image is formed more clearly. TV camera 3
The image signal output from 0 is input to the control circuit 45.

The working distance index projection optical system Se includes a working distance detecting light emitting diode (infrared LED) 31, which is disposed along a working distance detecting index optical axis 35a at 45 degrees with respect to the photographing optical axis 4. It is composed of a condenser lens 32, a working distance detection index slit 33, and a projection lens 34. The light from the working-distance detecting light emitting diode 31 travels along the working-distance detecting index optical axis 35a, and sequentially passes through the condenser lens 32, the working-distance detecting index slit 33, and the projection lens 34. The light is incident on the eye sphere F as light.

The working distance detecting optical system Sf comprises an imaging lens 36 for receiving the working distance detecting index light reflected by the eye spherical surface F, and a working distance detecting light receiving element (PSD).
37. The imaging lens 36 and the working distance detecting light receiving element 37 are provided with a working distance detecting optical axis 35b symmetrical with respect to the photographing optical axis 4 with the working distance detecting index optical axis 35a.
It is arranged along. Then, the working distance detecting light receiving element 37 outputs a light receiving signal accompanying the reception of the working distance detecting index light to the control circuit 45.

The focusing index projection optical system Sg is an optical system for adjusting the focus of the fundus photographing optical system Sb to the fundus of the eye E to be inspected, and includes a halogen lamp 38, a condenser lens 39, an automatic focusing index slit 40, It comprises a projection lens 41, a split prism 42, a condenser lens 44 and the half mirror 19. Among them, the halogen lamp 38, the condenser lens 39, the slit 40 for the automatic focus index, the projection lens 41, and the split prism 42 integrally form a movable portion 60. In addition, a plurality of fixation lamps (not shown) are incorporated in the focusing target projection optical system Sg. These fixation lights
The line of sight of the subject's eye E fixed by the fixation lamp incorporated in the alignment index projection optical system C is provided so as to be fixed at the same angle even after the mirror 25 and the concave lens 26 have retreated from the imaging optical axis 4. It was done.

An XY-axis drive mechanism 50 and a Z-axis drive mechanism 52 are interposed between the mount of the fundus photographing apparatus 1 and the mirror 3, and the position of the mirror 3 with respect to the mount is changed by these drive mechanisms. . The Z-axis drive mechanism 52 is a drive mechanism for moving the mirror body 3 in the Z direction. Here, the Z direction is a direction (left-right direction in FIG. 1) approaching / separating from the eye E to be examined. Note that the direction of the photographing optical axis 4 coincides with the Z direction. The XY-axis drive mechanism 50 moves the mirror body 3 to X
This is a driving mechanism for moving in the Y direction. Here, the X direction refers to a direction orthogonal to the Z axis in a horizontal plane (a direction perpendicular to the plane of FIG. 1). Also, the Y direction is
It refers to the vertical direction (vertical direction in FIG. 1).

The control circuit 45 receives signals from the television camera 10, the television camera 30, and the working distance detecting light receiving element 37, processes these signals in accordance with a predetermined procedure, and performs XY-axis driving mechanism 50, Z-axis driving This is a circuit for sending a control signal to the mechanism 52 and the like.

Next, the operation and operation procedure of the fundus photographing apparatus 1 will be described based on the flowcharts of FIGS. 2 and 3 and with reference to FIGS. The end point M in the flowchart of FIG. 2 matches the start point M in the flowchart of FIG. The step numbers in the following description correspond to the steps denoted by the same reference numerals in the flowcharts of FIGS. 2 and 3. The operation and operation procedures shown in the flowcharts of FIGS. 2 and 3 are (1) preliminary adjustment (corresponding to steps 101 to 109), (2) alignment (corresponding to steps 110 to 111), and (3). Working distance adjustment (corresponding to steps 112 to 114), (4) alignment correction (corresponding to steps 115 to 117), (5)
Focusing (corresponding to steps 118 to 121) and (6) fundus photographing (corresponding to step 122) can be divided into respective stages. Hereinafter, description will be given for each of these steps.

(1) Preliminary Adjustment First, when the photographing button of the fundus photographing apparatus 1 which is turned on and is in a standby state is pressed (step 101), an anterior eye image by the anterior eye observation optical system Sd is displayed on the monitor display 47. Is displayed (step 102). The subject fixes the head on the jaw table, and looks at the fixation lamp incorporated in the alignment target projection optical system Sc through the objective lens 5 according to the doctor's instruction (step 103). At this time, whether the subject's eye E is the right eye or the left eye is detected by the jaw base based on the position of the jaw base relative to the objective lens 5. A predetermined fixation light selected from a plurality of fixation lights for the left eye or the right eye is turned on based on a signal from the jaw table (step 10).
4).

FIG. 4 is a view showing the eye E to which the gaze is guided by the fixation lamp. FIG. 4A is a sectional view of the eye E cut along the XZ plane, and FIG. FIG. 2 is a front view of an eye E to be inspected. Ia is the left part of the iris as seen from the subject, and Ib is the right part of the iris. PC is the center of the pupil of the eye E, and its position on the XY coordinates is (X0, Y0).
It is. ER is the eye E to be examined viewed from the anterior segment observation optical system Sd.
And its position on the XY coordinates is (X1, Y1)
It is. In FIG. 4, the eye axis t of the subject's eye E is not in the front direction (Z-axis direction) but in the direction of the point S. Such a state can be considered, for example, in the following case.
When the subject, who is oblique, gazes at the front fixation lamp (fixation lamp in the Z direction), the eye axis t moves in a direction slightly rotated from the Z axis direction, for example, the direction of the point S as shown in FIG. Will be turned.
Further, even if the gaze is turned to the direction of the point S by turning on the fixation lamp in the direction of the point S to the subject who is not oblique, the eye axis t
Point in the direction of the point S as shown in FIG. In addition, the subject's eye E is
Although rotation occurs not only in the XZ plane but also in the YZ plane, a cross-sectional view cut in the YZ plane is omitted.

When a predetermined fixation lamp is turned on in this way (step 104) and the subject's eye E is fixed in the state shown in FIG. 4, the doctor next operates the jaw base and the monitor display 4
7 is adjusted so that the anterior segment of the subject's eye E is projected (Step 105), and the photographing button is pressed again (Step 106). The operation of the fundus imaging apparatus 1 from the second button pressing operation to the completion of fundus imaging is automated.

By the second button pressing operation, the alignment light emitting diode 21a and the working distance detecting light emitting diode 31 are turned on (step 107). In this state, until the eyeball reflection image (Purkinje image) due to the reflected light from the eyeball F of the alignment index light can be clearly recognized in the anterior eye image captured on the imaging screen of the television camera 30,
The shaft driving mechanism 52 is driven to move the mirror 3 toward the eye E (steps 108 and 109).

(2) Alignment When the Purkinje image is clearly recognized on the imaging screen of the television camera 30 as described above (step 109), alignment in the XY directions is performed next. This alignment is performed by automatically driving the mirror body 3 in the XY directions so that the Purkinje image falls within a predetermined range on the imaging screen of the television camera 30 (steps 110 and 111).
The operation in steps 110 and 111 will be described below in detail. First, the anterior eye image and the Purkinje image of the eye E are received by the television camera 30, and an image signal from the television camera 30 is input to the control circuit 45.
The control circuit 45 detects the position of the Purkinje image in the imaging screen.

FIG. 5 shows an image screen K of the television camera 30. The control circuit 45 sends a driving signal to the XY-axis driving mechanism 50 so that the Purkinje image Q falls within a predetermined range R in the imaging screen K. For example, as shown in FIG. 5, if the Purkinje image Q is within the range of Kx1 in the X-axis coordinate on the imaging screen K, the mirror 3 is moved so that the Purkinje image Q moves to the left in the imaging screen K. The movement of the mirror body 3 is performed by the control circuit 45 sending a drive signal to the XY-axis drive mechanism 50. If the Purkinje image Q is in the range of Kx3, the XY-axis driving mechanism 50 is controlled so that the Purkinje image Q moves rightward in the captured image K. As a result, the Purkinje image Q is guided to the range of Kx2 on the imaging screen K. When the Purkinje image Q is in the range of Kx2, the mirror 3 is not moved in the X direction. That is, Kx2 is mirror 3
Is in the range of insensitivity regarding the movement in the X direction. Similarly, in the Y direction, the XY-axis driving mechanism 50 is controlled so that the Purkinje image Q enters the dead range ky2. In this way, the Purkinje image Q is guided within the predetermined range R in the imaging screen K. The anterior ocular segment observation optical system Sd is configured such that an imaging target on the imaging optical axis 4 is captured within a range R in the imaging screen K.
It is arranged on the mirror body 3. Therefore, when the Purkinje image Q falls within the range R, the imaging optical axis 4 is in a state of being coincident with the position (X1, Y1) of the vertex ER of the eye E in the X and Y directions.
In FIG. 5, the range R is exaggerated with respect to the size of the Purkinje image Q in order to facilitate understanding of the operation description. For the same reason, the position of the Purkinje image Q is greatly exaggerated with respect to the pupil center position.

(3) Adjustment of Working Distance The alignment is completed when the Purkinje image Q falls within the predetermined range R in the imaging screen K as described above (step 111). And, in the range R, the Purkinje image Q
The working distance is adjusted while controlling the XY-axis driving mechanism 50 while following the Purkinje image Q so that the state where the mark is entered, that is, the state where the alignment is maintained, is maintained. To adjust the working distance, the light receiving element 37 for detecting the working distance uses the working distance detection index light (eyeball reflected light).
Until light is received, the mirror 3 is advanced toward the eye E (step 112). Control circuit 4
5 detects that the working-distance detecting light receiving element 37 has received the working-distance detection index light (eyeball reflected light) (step 113), and when the XY-axis driving mechanism 50 and the Z-axis driving mechanism 5
The second driving operation is stopped (step 114).

The operations in steps 112, 113 and 114 will be described below in detail. First, when the alignment in the XY directions is completed (step 111), the working distance detection index light is projected onto the eye E by the working distance index projection optical system Se. However, when the alignment is completed, the fundus photographing optical system Sb is located at a position farther from the eye E than the working distance. In such a state, the working distance detection index light has a positional relationship such that it does not enter the vertex (vertex of the eye to be inspected) ER of the eye spherical surface F, and the fundus imaging optical system Sb,
The working distance index projection optical system Se is disposed on the mirror body 3. Therefore, the reflected light from the eye spherical surface F is not received by the light receiving element 37 for detecting the working distance. Thereafter, the control circuit 45
Sends a drive signal to the Z-axis drive mechanism 52 to move the mirror body 3 along the Z-axis in a direction approaching the eye E (step 112). When the mirror body 3 reaches a certain distance with respect to the eye E to be examined, the index light from the working distance index projection optical system Se is incident on the vertex ER of the eye to be inspected on the spherical surface F, and the reflected light is used to detect the working distance. The light is received by the light receiving element 37 (step 113). In this state, the fundus photographing optical system S
The fundus photographing optical system Sb and the working distance index projection optical system Se are disposed on the mirror body 3 in such a positional relationship that the distance b with respect to the eye E becomes the working distance. When receiving the reflected light, the working distance detecting light receiving element 37 outputs a light receiving signal to the control circuit 45. Then, the control circuit 45 changes the stop signal to Z
The operation is sent to the axis driving mechanism 52 to stop the operation of the Z-axis driving mechanism 52. This stops the movement of the mirror body 3 in the Z direction.
Further, the maintenance of the alignment state in the XY directions, which has been performed while following the Purkinje image, is terminated by temporarily stopping the XY-axis driving mechanism 50 (step 11).
4).

(4) Alignment Correction When the working distance adjustment is completed as described above, the alignment is corrected next. The alignment correction is performed while detecting the pupil center PC position based on the anterior segment image of the subject's eye E captured by the television camera 30 (step 11).
5) Move the mirror 3 so that the photographing optical axis 4 coincides with the pupil center PC (steps 116 and 117). The movement of the mirror 3 is performed by the control circuit 45 sending a drive signal to the XY-axis drive mechanism 50.

The operations in steps 115, 116 and 117 will be described below in detail. First, an image of the anterior segment of the eye E is received by the television camera 30, and an image signal from the television camera 30 is input to the control circuit 45.
The control circuit 45 determines the position of the pupil center PC in the photographing screen from the image signal.

FIG. 6 is a diagram showing a method in which the control circuit 45 determines the position of the pupil center PC on the image screen K. In this figure, a photographing screen K of the pupil center PC in the XY plane is shown.
The manner in which the luminance level of the anterior ocular segment image is calculated in order to determine the middle position is shown. FIG. 6A is an anterior segment image captured by the television camera 30. FIG. 6B is a scanning line (a dashed line in FIG. 6A) of a video signal in the anterior segment image. The upper luminance level signal. By performing the binarization at the reference level indicated by the broken line N in FIG. 6B, the pupil P portion and the iris I portion can be selected from the anterior eye image. That is, in FIG. 6B, a range p with a low luminance level corresponds to the pupil P, and a range i with a relatively high luminance corresponds to the iris I. Then, the geometric center of gravity C is detected for the range p where the luminance level is low, and the geometric center of gravity C is obtained as the position of the pupil center PC on the photographing screen K.

The control circuit 45 sends a drive signal to the XY-axis drive mechanism 50 so that the pupil center position detected in this way falls within a predetermined range R on the image screen K. The method of guiding the pupil center position to the predetermined range R in the imaging screen K is the same as the method of guiding the position of the Purkinje image Q to the range R in the imaging screen K in the above-described alignment. Thus, the center position of the pupil is within the predetermined range R of the imaging screen K.
When entering, the photographing optical axis 4 coincides with the pupil center PC of the eye E to be examined. Thereby, the photographing optical axis 4 is shifted to the left side portion Ia of the iris,
It will be located equidistant from the right part Ib. Also,
When the alignment correction is completed in this way, the fundus imaging optical system Sb has been guided to the operating position (operating position in the XYZ directions).

(5) Focusing When the alignment correction is completed as described above, a correction completion signal is output from the control circuit 45 to the optical path switching mechanism 54, and the optical path switching mechanism 54 receives the correction completion signal from the mirror 25 and the concave lens 26. Is retracted from the photographing optical axis 4 and focusing is performed by the following known method. In other words, the control circuit 45 turns on the halogen lamp 38 (step 118), and the movable section 60 of the focusing target projection optical system G until the focus is detected.
And the focus lens 7 of the fundus imaging optical system Sb are moved in conjunction with each other in the Z direction (steps 119 and 120). The movement of the movable section 60 and the focus lens 7 is performed by sending a drive signal from the control circuit 45 to the focusing drive mechanism 56. When the focusing is completed, the halogen lamp 38 is turned off (step 121).

(6) Fundus Photographing When the focusing is completed as described above, the strobe light emitting circuit 57 controlled by the control circuit 45 causes the strobe discharge tube 11 to emit light. Is photographed (step 122). The imaging optical axis 4 is the pupil center P
Since the alignment is corrected so as to penetrate C, the illumination light from the strobe discharge tube 11 is projected onto the fundus without being blocked by the iris I. In addition, the fundus image is not obstructed by the iris during photographing. Therefore, the fundus image captured by the television camera 10 is clear. Even in the case where the rotation angle of the eyeball of the eye to be examined becomes extremely large depending on the position of the fixation lamp to be gazed at, it is also impossible to predict at all what direction the eye to be examined E is rotated as in a perspective view. Even in such a case, a clear fundus image can be obtained. After photographing the fundus, the mirror 3 returns to the initial standby position (step 123).
It goes into a standby state.

Although the embodiment of the present invention has been described based on the fundus photographing apparatus 1, the operating position determining apparatus for an ophthalmologic apparatus according to the present invention captures the pupil position of the eye to be inspected and the pupil of the eye to be inspected. The present invention can be widely applied to all ophthalmologic apparatuses that perform inspection, observation, and photographing by using. In addition, although the description has been given based on the fundus imaging apparatus 1 including the fundus imaging optical system Sb as the main optical system, the main optical system may include both the imaging function and the observation function, or only one of the functions. May be provided.

[0045]

As described above, according to the operating position determining apparatus for an ophthalmologic apparatus of the present invention, the position of the pupil can be accurately detected, and in particular, the part deeper than the iris of the eye to be examined can be detected through the pupil. In the case of photographing and observing, it is possible to clearly photograph and observe the site without being blocked by the iris. In addition, it is possible to cope with a wide range of movement of the line of sight of the eye to be inspected, and even if the line of sight of the eye to be inspected is largely shaken at an arbitrary angle, it is possible to clearly shoot and observe. Furthermore, even if the angle of the eye to be inspected cannot be predicted as in the case of a strabismus, it is possible to clearly photograph and observe. In addition, it is possible to configure an ophthalmologic apparatus that automatically determines an operation position in the order of alignment adjustment, working distance adjustment, and alignment correction.

According to the operating position determining apparatus for a fundus photographing apparatus of the present invention, the illumination light can be projected onto the fundus without being blocked by the iris, and the fundus image can be photographed without being blocked by the iris. be able to. Further, it is possible to cope with a wide range of movement of the line of sight of the eye to be inspected, and it is possible to clearly capture a fundus image even when the line of sight of the eye to be inspected is largely swung at an arbitrary angle. Furthermore, even when the angle of the eye to be inspected cannot be predicted, as in the case of a perspective view, a fundus image can be clearly captured. In addition, it is possible to configure a fundus imaging apparatus in which an operation position is automatically determined in the order of alignment adjustment, working distance adjustment, and alignment correction.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a fundus imaging apparatus.

FIG. 2 is a flowchart showing an operation / operation procedure of the fundus imaging apparatus.

FIG. 3 is a flowchart illustrating an operation / operation procedure of the fundus imaging apparatus.

4A and 4B are diagrams illustrating an eye to be examined whose gaze is guided by a fixation lamp, FIG. 4A is a cross-sectional view of the eye to be examined cut along an XZ plane, and FIG. 4B is a front view of the eye to be inspected; is there.

FIG. 5 is a diagram showing an imaging screen of a television camera.

6A and 6B are diagrams illustrating a method in which a control circuit obtains the position of the center of a pupil on an imaging screen. FIG. 6A illustrates an anterior eye image captured by a television camera, and FIG. FIG. 4 is a diagram illustrating a luminance level signal on a scanning line of a video signal in an eye image.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fundus imaging device 3 Mirror 4 Imaging optical axis 5 Objective lens 6 Perforated mirror 7 Focus lens 8 Relay lens 9 CCD light receiving surface 10 Television camera 11 Strobe discharge tube 12, 13 Condenser lens 14 Circular slit 15 Mirror 16 Illumination optical axis Reference Signs List 18 Condensing lens 19 Half mirror 20 Condensing lens 21a Light emitting diode for alignment 21b Light source for anterior eye illumination 22 Mirror 23 Condensing lens 24 Half mirror 25 Mirror 26 Concave lens 27a Alignment index optical axis 27b Anterior eye observation optical axis 28 Front Eye observation lens 29 CCD light receiving surface 30 TV camera 31 Working distance detecting light emitting diode 32 Condensing lens 33 Working distance detecting index slit 34 Projection lens 35 a Working distance detecting index optical axis 35 b Working distance detecting optical axis 36 Imaging lens 37 working distance Separation detection light-receiving element 38 Halogen lamp 39 Condensing lens 40 Automatic focus index slit 41 Projection lens 42 Split prism 44 Condensing lens 45 Control circuit 47 Monitor display 50 XY-axis driving mechanism 52 Z-axis driving mechanism 54 Optical path switching mechanism 56 Focusing drive mechanism 57 Strobe light emitting circuit 60 Movable part Sa Illumination optical system Sb Fundus imaging optical system Sc Alignment index projection optical system Sd Anterior ocular segment observation optical system Se Working distance index projection optical system Sf Working distance detection optical system Sg Focus index Projection optical system K Imaging screen L Scan line E Eye to be inspected F Eye sphere t Eye axis P Pupil I Iris PC Center of pupil ER Apex of eye to be inspected Q Purkinje image

Claims (2)

[Claims] An operating position determining apparatus for an ophthalmic apparatus having, as a main optical system, an optical system for photographing and / or observing a predetermined part of an eye to be inspected, and projects an alignment index light onto an eye spherical surface of the eye to be inspected. An alignment index projection optical system; an anterior eye observation optical system that receives an anterior eye image of the subject's eye and receives reflected light of the alignment index light from the ocular sphere as an ocular spherical reflection image; An alignment unit that guides the main optical system so that an optical axis of the main optical system coincides with the vertex of the eye to be inspected based on the position of the reflected spherical image of the eye observed by the unit observation optical system; In a state where the optical axis of the optical system coincides with the vertex of the subject's eye, the reflected light from the vertex of the subject's eye of the working distance detection index light projected obliquely to the subject's eye is received at a predetermined position. The main optics Working distance adjusting means for adjusting the working distance by moving the optical axis in the axial direction; and the optical axis of the anterior ocular segment image received by the anterior ocular segment observation optical system is adjusted by the alignment means based on the center of the pupil. An operation position determining device for an ophthalmologic apparatus, comprising: an alignment correcting unit that guides the main optical system guided so as to coincide with the vertex of the optometry so that the optical axis thereof coincides with the center of the pupil. 2. An operation position determining apparatus for a fundus photographing apparatus, comprising: an illumination optical system for illuminating a fundus of an eye to be examined with illumination light; and a fundus imaging optical system for photographing the fundus based on the illumination light. An alignment index projection optical system that projects alignment index light onto the eye sphere of the optometry, and receives an anterior segment image of the eye to be inspected and receives reflected light of the alignment index light from the eye sphere as an eye spherical reflection image An anterior ocular segment observation optical system, and based on the position of the ocular spherical reflection image observed by the anterior ocular segment observation optical system, the fundus imaging optical system such that the optical axis of the fundus imaging optical system coincides with the vertex of the eye to be inspected. And an apex of the working distance detection index light projected from the oblique front to the eye under the condition that the optical axis of the fundus photographing optical system coincides with the apex of the eye to be inspected by the alignment means. Or Working distance adjusting means for adjusting the working distance by moving the fundus photographing optical system in the direction of its optical axis so that the reflected light can be received at a predetermined position; and Based on the pupil center of the eye image, the fundus imaging optical system guided by the alignment means so that its optical axis coincides with the vertex of the eye to be examined is guided so that its optical axis coincides with the pupil center. An operation position determination device for a fundus imaging device, comprising: an alignment correction unit.