JPH11313800A - Ophthalmological device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an ophthalmological device photographable while aligning the photographing optical axis with the pupil center at all times even at the time of a peripheral photographing. SOLUTION: A photographer operates a fixation target moving switch 30 while looking at a fundus image projected to a television monitor 6 and at a character K for indicating the position of a fixation target 23a presented to a subject and guides the line of sight of the subject so as to photograph a desired part. Images of alignment visual marks AL and AR illuminated by light sources 18L and 18R for visual mark illumination through optical fibers 17L and 17R are formed near an image pickup means 22, and alignment visual marks images AL' and AR' are displayed on the television monitor 76 together with the fundus image. The photographer operates a back-and-forth and left-and- right movement operation means 7 and a vertical movement switch 8 so as to overlap the alignment visual mark images AL' and AR' and aligning reference marks ML and MR moved by being linked with and position of the fixation target 23a displayed on the television monitor 6 and aligns an eye E to be tested with a main body optical system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmic apparatus used in an ophthalmic clinic or the like.

[0002]

2. Description of the Related Art In a conventional fundus camera, a target light beam is projected on an eye to be inspected, a reflected image thereof is observed, a position of the reflected image is adjusted to a predetermined position, and a photographing optical axis passes through a pupil and an optical system of the eye to be inspected. Perform positioning so as to maintain a predetermined distance.

[0003]

However, in the above-mentioned conventional example, when the peripheral portion is photographed with the optic disc positioned at the center of the photographing range, the pupil becomes apparently smaller and the position of the reflected image is reduced. Since the pupil is decentered, the imaging optical axis is positioned so as not to pass through the center of the pupil. Therefore, in an eye to be examined having a small pupil diameter, one side of the illumination light is easily blocked by the iris, and thus the fundus cannot be uniformly illuminated. In particular, when stereoscopic imaging is performed with the imaging optical axis decentered left and right from the pupil and aligned, if the distribution center of the left and right does not coincide with the center of the pupil, the amount of light blocked by the iris in the left and right images is reduced. Due to the difference, a difference occurs in the amount of illumination light, and it is difficult to obtain a stereoscopic effect even when the images are stereoscopically viewed using the images, and furthermore, there is a problem that a flare is generated because the alignment is shifted from an appropriate position.

An object of the present invention is to solve the above-mentioned problems,
It is an object of the present invention to provide an ophthalmologic apparatus that performs positioning so that the imaging optical axis always passes through the center of the pupil even in peripheral imaging.

[0005]

An ophthalmologic apparatus according to the present invention for achieving the above object provides a fixation target presenting means for guiding a subject's line of sight to a plurality of locations, and observes a fundus image of the subject's eye. Fundus observation means, alignment assisting means for projecting a target light beam onto the anterior segment of the subject's eye and guiding the reflected image to the fundus observation means, and a reference mark for positioning the reflected image on the fundus observation means. Display position control means for displaying at different positions according to the fixation target presenting means.

An ophthalmologic apparatus according to the present invention includes a fixation target presenting means for guiding the line of sight of a subject to a plurality of places, an imaging optical system for guiding a fundus image of the eye to be examined to an imaging means, and A fundus oculi observation means comprising display means for displaying, an alignment assisting means for projecting an optotype light beam to the anterior segment of the eye to be examined, guiding a reflected image thereof to the image pickup means and displaying the reflected image on the display means, Display position control means for displaying a reference mark for aligning the reflection image at a different position in accordance with the fixation target presenting means.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 is a perspective view of a fundus camera according to a first embodiment. In order to align the fundus camera with the eye to be inspected, a non-dispersive image of the eye to be inspected using infrared light and observed by a television monitor. It is a pupil fundus camera. A stage 2 is mounted on a base 1 so as to be movable three-dimensionally, and a forehead rest 3 for fixing a face and a chin rest 4 are provided on the subject side of the base 1.
Is fixed. On the stage 2, there are provided a measuring unit housing 5 having a built-in optical system, a television monitor 6, operating means 7 for moving back and forth, right and left, and a vertical movement switch 8. Is attached.

FIG. 2 shows a configuration diagram of the measuring unit. In the measuring unit housing 5, a fundus photographing means A is formed on the optical path behind the objective lens 11 facing the eye E to be examined. From the side, a perforated mirror 12 having a photographing aperture 12a in the hole, a focus lens 13 for moving in the optical path direction to adjust the focus, a photographing lens 14, a switching mirror 15
Are sequentially arranged, and the image plane 9
and a digital camera 9 having an image memory 9b. As shown in FIG. 3, the apertures of the perforated mirror 12 are provided with an imaging stop 12a and alignment targets AL and AR having different shapes to be projected on the subject's eye E on both sides of the imaging stop 12a. Alignment target
AL and AR are illuminated by optotype illumination light sources 18L and 18R via optical fibers 17L and 17R, and a positioning assisting means B is constituted by these members.

In the incident direction of the perforated mirror 12,
A known fundus illuminating unit C that constantly emits infrared light and emits a visible flash at the time of photographing is arranged, and a half mirror 19 is arranged on the optical path in the reflection direction of the switching mirror 15. A fundus observation unit D is configured in the reflection direction of the half mirror 19, and includes a lens 20, an imaging lens 21, and an imaging unit 2.
In the transmission direction of the half mirror 19, a liquid crystal element 23 having an arbitrary transmission area as shown in FIG. 4 as a fixation target 23a and a backlight 24 are arranged. F is configured.

The outputs of the digital camera 9 and the image pickup means 22 are connected to an image processing section 25, and the output of the image processing section 25 is connected to the television monitor 6. Also, backlight 2
The output of the liquid crystal control means 26 is connected to 4, and the output of the CPU 27 is connected to the liquid crystal control means 26. Furthermore,
The output of the CPU 27 is connected to the control means 28, and the output of the control means 28 is connected to the fundus illuminating means C and the switching mirror 15, and the outputs of the imaging mode selection switch 29, the fixation target moving switch 30, and the imaging switch 31 CPU27
It is connected to the.

In such a configuration, the photographer should make sure that the optical axis of the fundus photographing means A passes through the center of the pupil Ep of the eye E to be examined, and that the objective lens 11 and the cornea Ec maintain an appropriate distance.
The alignment between the main optical system and the eye E is performed using the reflection images of the alignment targets AL and AR.

That is, the subject stands on the chin rest 4 while pressing the forehead against the forehead 3. In response to a command from the CPU 27, the fundus illumination means C emits infrared light to
Er is constantly illuminated. At this time, the control means 28 turns on the optotype illumination light sources 18L and 18R, and further, the liquid crystal control means 26 turns on the backlight 24 and transmits only predetermined cells of the liquid crystal element 23 as shown in FIG. In this state, the fixation target 23a is presented to the subject's eye E.

The fundus image illuminated in this way includes a pupil Ep,
Objective lens 11, aperture 1 for aperture of apertured mirror 12
2a, through the focus lens 13, the photographing lens 14,
The light is reflected downward by the switching mirror 15, further reflected leftward by the half mirror 19, forms an image in the vicinity of the lens 20, and re-images in the vicinity of the image sensor 22 by the taking lens 21. This image is converted into a video signal, and displayed on the television monitor 6 by the image processing unit 25. The photographer observes the fundus image reflected on the television monitor 6, and confirms the photographing site, the presence or absence of flare, and the focus state. .

A character K indicating the position of the fixation target 23a presented to the subject as shown in FIG.
It is projected on. The photographer operates the fixation target movement switch 30 while watching the fundus image and the character K, and guides the subject's gaze so that a desired part can be photographed.

The images of the alignment targets AL and AR illuminated by the target illumination light sources 18L and 18R via the optical fibers 17L and 17R are projected onto the anterior segment of the eye E through the objective lens 11, The reflected image is reflected by the cornea Ec, passes through the objective lens 11, passes through the same path as the fundus image, and forms an image near the imaging means 22, and the alignment target image AL on the television monitor 6 together with the fundus image. ', AR' is displayed.

These alignment optotype images AL 'and AR'
Is a target for assisting the alignment between the subject and the main body optical system, so the photographer can clearly see the outline of this reflected image,
In addition, the front / rear / left / right movement operation means 7 and the up / down movement switch 8 are operated so as to overlap with the positioning reference marks ML and MR moving in conjunction with the position of the fixation target 23a displayed on the television monitor 6, and The optometry E and the main body optical system are aligned.

FIG. 5 shows a character K and a positioning reference mark when photographing is performed centering on the macula of the fundus of the eye E to be examined.
This shows the arrangement of ML and MR. The character K is arranged at the center of the screen, and the alignment reference marks ML and MR are arranged almost symmetrically at a substantially middle position in the vertical direction.

FIG. 6 shows a photographing range in the case of photographing by a group examination or the like. The middle of a line connecting the optic disc and the macula is located substantially at the center of the screen. In this case, the character K is eccentric to the right and the alignment reference marks ML, MR
Are eccentrically displayed in the same direction as the character K.

FIG. 7 shows a case where the optic disc is arranged at the center of the screen for imaging. The character K is located at the right end, and the alignment reference mark MR is shown in FIG. In comparison, the eccentricity is displayed further eccentric to the right, and the positioning reference mark ML is not displayed because it is outside the display range.

FIG. 1 shows an arrangement for photographing the left eye of the subject. When photographing the right eye, the positions of the nipple and the macula are switched to the left and right. The marks ML and MR are displayed eccentrically to the left in the opposite direction to the case of FIGS.

After the desired imaging region is obtained by such an operation and the proper alignment is completed, the photographing switch 31 is operated to photograph the fundus Er. When the examiner operates the photographing switch 31, the CPU 27 detects this input, the control means 28 retracts the switching mirror 15 out of the optical path, the digital camera 9 starts storing light for photographing a still image, and the fundus illumination. Means C emits a visible flash. This flash is reflected by the perforated mirror 12 and illuminates the fundus Er after passing through the objective lens 11.

The fundus image illuminated in this manner is converted into an objective lens 11, a photographic stop 12 a in a hole of a perforated mirror 12,
The light passes through the focus lens 13 and the photographing lens 14 and forms an image on the imaging surface 9a of the digital camera 9. This image is converted into a digital signal, stored in the image memory 9b of the digital camera 9, and also converted into a video signal, reproduced on the television monitor 6, and the shooting ends. At this time, the character K indicating the fixation target position and the alignment reference marks ML, MR are not displayed.

When performing stereoscopic photography, the photographing mode selection switch 29 is operated to set the stereoscopic photography mode. In conjunction with this switch operation, as shown in FIG.
The character K indicating a is presented such that the optic disc is positioned at the center of the screen. Then, only the optotype illumination light source 18R is turned on, only the image of the alignment optotype AR is projected onto the eye E, and only the alignment reference mark MR is positioned between the image center on the television monitor 6 and the fixation target presentation position. 2/3 of eccentricity
It is displayed at a position of about ３. The photographer matches the reflection image of the alignment target AR with the positioning reference mark MR and shoots the right image of the pair of stereoscopic images.

Next, an alignment reference mark ML is displayed on the television monitor 6 at the position where the alignment reference mark MR was displayed, as shown in FIG.
Is turned off, and only the optotype illumination light source 18L is turned on. The photographer aligns the reflected image of the alignment target AL with the alignment reference mark ML, photographs the left image of the pair of stereoscopic images, and ends the stereoscopic photography.

As described above, when stereoscopic photographing is performed with the photographing optical axis decentered, a pupil diameter wider than usual is required to obtain a good image. In particular, in the case of peripheral imaging in which the nipple is arranged at the center of the screen and the pupil Ep is apparently smaller, the optical axis of the right image and the optical axis of the left image of stereoscopic imaging are centered on the pupil Ep. As a more accurate distribution must be arranged.

In the three-dimensional photographing according to the present embodiment, the light sources 18L and 18R for illuminating the target are sequentially turned on in accordance with the right and left photographing, so that the alignment targets AL and AR have the same shape. Since the reflection images of the alignment targets AL and AR corresponding to the alignment reference marks ML and MR become clear, efficient imaging can be performed. Although the fixation target presenting means for guiding the line of sight to an arbitrary position has been described, the apparatus for presenting the fixation target 23a at a fixed position according to the left and right eyes or the imaging magnification may also be used for the alignment reference marks ML, MR. Are displayed at different positions according to the fixation target position, a similar effect can be obtained.

FIG. 10 shows a second embodiment, which is a mydriatic fundus camera in which the photographer observes the subject's eye with the naked eye through a finder. The same reference numerals as in the first embodiment denote the same members. The switching mirror 40 is disposed at the position of the switching mirror 15 of the fundus photographing means A in the first embodiment, and the half mirror 41 is disposed in the reflection direction of the switching mirror 40. In the left reflection direction of the half mirror 41, a field lens 42, a finder lens 43
Are arranged to constitute a finder optical system. A lens 44, a mirror 45, a second liquid crystal element 46, and a second liquid crystal lighting means 47 are sequentially arranged in the rightward reflection direction, which is the transmission direction of the half mirror 41 as viewed from the photographer e. The output of the second liquid crystal lighting means 47 is connected to the liquid crystal control means 26.

The fundus illumination means C constantly emits visible light,
The fundus Er is constantly illuminated by the visible light. The photographer can illuminate the fundus Er and the cornea of the eye E illuminated by the stationary light.
The reflection images of the alignment targets AL and AR from Ec can be observed through the finder optical system.

The second liquid crystal element 46 is controlled by the liquid crystal control means 26, and forms a light transmitting portion having a reference optotype shape as in the first embodiment. The reference marks ML and MR are illuminated by the second liquid crystal illuminating means 47, reflected by the mirror 45, and imaged by the lens 44 near the field lens. The photographer uses the finder lens 43 to obtain the images of the fiducial marks ML and MR and the fundus image, and the alignment targets AL and AR.
Can be observed in a superimposed manner.

Therefore, the photographer “e” has the viewfinder lens 43.
While observing the fundus image while looking through the
The same effect as in the first embodiment can be obtained by positioning the reflected image of the AR so as to match the reference marks ML and MR. In the second embodiment, two liquid crystal display means are used. However, one liquid crystal display means is partially used for projecting a fixation target onto a subject and a reference mark ML, MR for a photographer.
They may be used separately for projection.

[0031]

As described above, the ophthalmologic apparatus according to the present invention adjusts the position so that the reflected image of the luminous flux of the target matches the reference mark while observing the fundus image, thereby photographing the periphery of the eye to be inspected. In this case, the imaging optical axis can be accurately positioned at the center of the pupil, and the imaging optical axis can be accurately allocated to the center of the pupil for positioning. On the other hand, a left and right stereoscopic image with a small light amount difference can be photographed, and a photographed image having a good stereoscopic effect can be obtained.

In the ophthalmologic apparatus according to the present invention, the reference mark for positioning is displayed at a different position corresponding to the fixation target position, and the optotype luminous flux projected to the anterior segment of the subject's eye at that position. By aligning the reflected images so that they are aligned, it is possible to accurately position the photographing optical axis at the center of the pupil even when photographing the periphery of the eye to be inspected. Since the positioning can be performed by allocating the photographing optical axis, a left and right stereoscopic image with a small light amount difference can be photographed even for the eye to be examined having a small pupil diameter, and a photographed image having a good stereoscopic effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a fundus camera according to a first embodiment.

FIG. 2 is a configuration diagram.

FIG. 3 is a front view of an auxiliary target.

FIG. 4 is an explanatory diagram of a fixation target.

FIG. 5 is an explanatory diagram of a display screen in a case where imaging is performed mainly on the macula.

FIG. 6 is an explanatory diagram of a display screen at the time of a group examination.

FIG. 7 is an explanatory diagram of a display screen when the optic disc is centered.

FIG. 8 is an explanatory diagram of a right display screen at the time of stereoscopic imaging.

FIG. 9 is an explanatory diagram of a left display screen.

FIG. 10 is a configuration diagram of a fundus camera according to a second embodiment.

[Explanation of symbols]

 Reference Signs List 1 base 5 measuring unit housing 6 television monitor 7 operating means 8 up / down switch 9 digital camera 12 perforated mirror 12a shooting aperture 15 switching mirror 17L, 17R optical fiber 18L, 18R optotype illumination light source 22 imaging means 23 liquid crystal element Reference Signs List 25 image processing unit 26 liquid crystal control means 27 CPU 28 control means 29 shooting mode selection switch 30 fixation target moving switch 31 shooting switch

Claims (4)

[Claims] 1. A fixation target presenting means for guiding a gaze of a subject to a plurality of places, a fundus observing means for observing a fundus image of a subject's eye, and a projecting target light beam onto an anterior eye of the subject's eye. Positioning assistance means for guiding a reflected image to the fundus observation means, and display position control means for displaying a reference mark for positioning the reflection image on the fundus observation means at a different position in accordance with the fixation target presentation means. An ophthalmologic apparatus comprising: 2. The ophthalmologic apparatus according to claim 1, wherein the positioning target is a plurality of targets having different shapes, and the shape of the reference mark is made to correspond to the shape of the positioning target. 3. The ophthalmologic apparatus according to claim 1, wherein the alignment target is a plurality of selectable targets, and the fiducial mark is displayed in correspondence with the selected alignment target. 4. A fundus observation comprising a fixation target presenting means for guiding the line of sight of a subject to a plurality of places, an imaging optical system for guiding a fundus image of the eye to be examined to an imaging means, and a display means for displaying the fundus image. Means, an alignment assisting means for projecting a target light beam onto the anterior segment of the subject's eye, guiding the reflected image to the imaging means and displaying the reflected image on the display means, and a reference for aligning the reflected image on the display means An ophthalmologic apparatus comprising: display position control means for displaying a mark at a different position according to the fixation target presenting means.