JP4011731B2 - Ophthalmic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ophthalmic apparatus used in an ophthalmic clinic or the like.
[0002]
[Prior art]
In a conventional fundus camera, a target luminous flux is projected onto the eye to be examined, the reflected image is observed, the position of the reflected image is adjusted to a fixed position, the imaging optical axis passes through the pupil, and the eye to be examined and the optical system have a predetermined distance. Alignment is performed in such a way as to maintain.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional example, when the peripheral portion is imaged with the optic disc aligned with the center of the imaging range, the pupil is small and the position of the reflected image and the pupil are decentered. The axis is aligned so that it does not pass through the center of the pupil. Accordingly, the eye to be examined having a small pupil diameter cannot easily illuminate the fundus because one side of the illumination light is easily blocked by the iris. In particular, when stereoscopic imaging is performed with the imaging optical axis decentered left and right from the pupil, if the left and right distribution center does not match the center of the pupil, the amount of light blocked by the iris in the left and right images Due to the difference, there is a difference in the amount of illumination light, and it is difficult to obtain a stereoscopic effect even when stereoscopically viewed using these images. Further, there is a problem that flare occurs because the alignment is shifted from the proper position.
[0004]
An object of the present invention is to provide an ophthalmologic apparatus that eliminates the above-described problems and performs alignment so that the photographing optical axis always passes through the center of the pupil even during peripheral photographing.
[0005]
[Means for Solving the Problems]
To achieve the above object, an ophthalmologic apparatus according to the present invention includes a fixation target presenting means for presenting a fixation target for inducing a gaze of a subject to the subject's eye, and a fundus for observing a fundus image of the subject's eye. Alignment assisting means for guiding the reflected image from the cornea when the target luminous flux is projected onto the anterior segment of the eye to be examined to the fundus oculi observation means as a plurality of alignment targets having different shapes And a display control for displaying a plurality of reference marks on the fundus oculi observation means for aligning the plurality of alignment targets at positions corresponding to the positions of the fixation target presented by the fixation target presentation means. And the display control means displays the shape of the plurality of reference marks on the fundus oculi observation means in correspondence with the shape of the alignment target .
[0006]
Further, an ophthalmologic apparatus according to the present invention includes a fixation target presenting means for presenting a fixation target for guiding the subject's line of sight to the eye, a fundus observation means for observing a fundus image of the subject eye, A reflected image from the cornea when a target luminous flux is projected onto the anterior segment of the optometer is presented by the alignment assisting means for guiding the reflected image from the cornea as a plurality of alignment targets to the fundus observation means, and the fixation target presentation means Display control means for displaying, on the fundus oculi observation means, a plurality of reference marks for aligning the plurality of alignment targets at positions corresponding to the positions of the fixation target, the plurality of positions The alignment target can be selected, and the display control unit displays a reference mark corresponding to the selected alignment target on the fundus oculi observation unit .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail based on the embodiments shown in the drawings.
FIG. 1 is a perspective view of the fundus camera of the first embodiment. In order to align the fundus camera and the eye to be examined, non-scattering is performed by imaging the eye to be examined using infrared light and observing it with a television monitor. It is a pupil fundus camera. A stage 2 is placed on the base 1 so as to be movable three-dimensionally. A forehead support 3 and a chin rest 4 for fixing the face are fixed on the subject side of the base 1. On the stage 2, a measuring unit housing 5 incorporating an optical system, a television monitor 6, an operating means 7 for moving back and forth and right and left, and a vertical movement switch 8 are disposed. Is attached.
[0008]
FIG. 2 shows a configuration diagram of the measurement unit. In the measurement unit housing 5, the fundus photographing means A is configured on the optical path behind the objective lens 11 facing the eye E, and from the objective lens 11 side, A perforated mirror 12 having a photographing aperture 12 a in the hole, a focus lens 13 that moves in the optical path direction and adjusts the focus, a photographing lens 14, and a switching mirror 15 are sequentially arranged. A digital camera 9 having a built-in image memory 9b is mounted. As shown in FIG. 3, the aperture aperture of the perforated mirror 12 is provided with alignment targets AL and AR having different shapes projected onto the eye E on both sides of the imaging aperture 12a and the imaging aperture 12a. The alignment targets AL and AR are illuminated by the target illumination light sources 18L and 18R via the optical fibers 17L and 17R, and the alignment assisting means B is constituted by these members.
[0009]
Further, in the incident direction of the perforated mirror 12, a known fundus illumination means C that constantly emits infrared light and emits visible flash light at the time of photographing is disposed. A mirror 19 is provided. The fundus oculi observation means D is configured in the reflection direction of the half mirror 19, and the lens 20, the imaging lens 21, and the imaging means 22 are arranged. In the transmission direction of the half mirror 19, the fixation target 23a is shown in FIG. A fixation target presenting means F is configured by arranging a liquid crystal element 23 and a backlight 24 having an arbitrary transmission region as shown.
[0010]
Outputs of the digital camera 9 and the imaging means 22 are connected to the image processing unit 25, and outputs of the image processing unit 25 are connected to the television monitor 6. Further, the output of the liquid crystal control means 26 is connected to the backlight 24, and the output of the CPU 27 is connected to the liquid crystal control means 26. Further, 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 illumination means C and the switching mirror 15, and the photographing mode selection switch 29, the fixation target moving switch 30, and the photographing switch 31 are connected. An output is connected to the CPU 27.
[0011]
In such a configuration, the photographer can align the alignment index AL, so that the optical axis of the fundus photographing means A passes through the center of the pupil Ep of the eye E and the objective lens 11 and the cornea Ec are kept at an appropriate distance. The main body optical system and the eye E are aligned using the AR reflection image.
[0012]
That is, the subject stands by with the chin placed on the chin rest 4 and the forehead 3 pressed against the forehead. In response to a command from the CPU 27, the fundus illumination means C emits infrared light to illuminate the fundus Er constantly. At this time, the control means 28 turns on the target illumination light sources 18L and 18R, and 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 eye E.
[0013]
The fundus image illuminated in this way passes through the pupil Ep, the objective lens 11, the photographing aperture 12a of the hole portion of the perforated mirror 12, the focus lens 13, and the photographing lens 14, reflected downward by the switching mirror 15, and further half The light is reflected to the left by the mirror 19 and forms an image near the lens 20, and the image is re-imaged near the image sensor 22 by the photographing lens 21. This image is converted into a video signal and is 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. .
[0014]
Further, as shown in FIG. 5, the character K indicating the position of the fixation target 23 a presented to the subject is combined with the fundus image by the image processing unit 25 and displayed on the television monitor 6. The photographer operates the fixation target moving switch 30 while viewing the fundus image and the character K to guide the subject's line of sight so that a desired part can be photographed.
[0015]
The images of the alignment targets AL and AR illuminated by the target illumination light sources 18L and 18R through the optical fibers 17L and 17R are projected onto the anterior eye portion of the eye E through the objective lens 11 and are cornea Ec. The reflected image passes through the objective lens 11 and then passes through the same path as the fundus image to form an image in the vicinity of the imaging means 22, and is aligned with the fundus image on the television monitor 6 with the alignment visual target images AL ′ and AR. 'Is displayed.
[0016]
Since these alignment target images AL ′ and AR ′ are targets for assisting the alignment between the subject and the main body optical system, the photographer can clearly see the outline of the reflected image and can be seen on the TV monitor 6. The subject eye E and the main body optics are operated by operating the front / rear / left / right movement operating means 7 and the up / down movement switch 8 so as to overlap the alignment reference marks ML, MR that move in conjunction with the position of the fixation target 23a displayed on the screen. Perform system alignment.
[0017]
FIG. 5 shows the arrangement of the character K and the alignment reference marks ML and MR when photographing centering on the fundus macular of the eye E. The character K is arranged at the center of the screen and the alignment reference marks ML and MR are arranged. Are arranged substantially symmetrically at a substantially middle position in the vertical direction.
[0018]
FIG. 6 shows an imaging range in the case of imaging by group medical examination or the like, and the middle of the line connecting the optic nerve head and the macula is located at the approximate center of the screen. In this case, the character K is eccentric to the right, and the alignment reference marks ML and MR are also displayed eccentrically in the same direction as the character K.
[0019]
Further, FIG. 7 shows a case where the optic nerve head is placed at the center of the screen for photographing, and the character K is positioned toward the right end, and the alignment reference mark MR is compared with the case of FIG. Furthermore, it is displayed eccentrically in the right direction, and the alignment reference mark ML is not displayed because it is out of the display range.
[0020]
FIG. 1 shows an arrangement for photographing the subject's left eye. When photographing the right eye, the positions of the nipple and the macula are interchanged to the left and right, so that the character K and the alignment reference mark ML, MR is displayed eccentrically in the left direction opposite to the cases of FIGS.
[0021]
By such an operation, after a desired imaging region is obtained and proper positioning is completed, the imaging switch 31 is operated to image the fundus Er. When the examiner operates the photographing switch 31, the CPU 27 detects this input, and the control means 28 retracts the switching mirror 15 to the outside of the optical path, and the digital camera 9 starts light accumulation for taking a still image and 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.
[0022]
The fundus image thus illuminated passes through the objective lens 11, the photographing aperture 12 a in the hole of the perforated mirror 12, the focus lens 13, and the photographing lens 14, and forms an image on the imaging surface 9 a 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 converted into a video signal, which is reproduced on the television monitor 6, and the shooting is finished. At this time, the character K indicating the fixation target position and the alignment reference marks ML and MR are not displayed.
[0023]
When performing stereoscopic shooting, the shooting mode selection switch 29 is operated to set the stereoscopic shooting mode. In conjunction with this switch operation, as shown in FIG. 8, the character K indicating the fixation target 23a is presented such that the optic disc is located at the center of the screen. Then, only the target illumination light source 18R is lit, only the image of the alignment target AR is projected onto the eye E, and only the alignment reference mark MR is between the image center on the TV monitor 6 and the fixation target presentation position. It is displayed at a position of 2/3 to 3/4 of the eccentric amount. The photographer photographs the right image of the pair of stereoscopic images by aligning the reflected image of the alignment target AR with the alignment reference mark MR.
[0024]
Next, on the television monitor 6, the alignment reference mark ML is displayed at the position where the alignment reference mark MR was displayed, as shown in FIG. 9, and the target illumination light source 18R is turned off and is used for target illumination. Only the light source 18L is lit. 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 imaging.
[0025]
Thus, when stereoscopic imaging is performed with the imaging optical axis decentered, a wider pupil diameter than usual is required to obtain a good image. In particular, in the case of peripheral photography where the nipple is placed in the center of the screen, the pupil Ep is apparently small, so the optical axis of the right image and the optical axis of the left image in stereo photography are centered on the pupil Ep. It must be sorted and arranged more accurately.
[0026]
In the stereoscopic shooting according to the present embodiment, the target illumination light sources 18L and 18R are sequentially turned on according to the left and right shootings, particularly when the alignment targets AL and AR have the same shape, the alignment reference. Since the reflected images of the alignment targets AL and AR corresponding to the marks ML and MR are clarified, efficient shooting can be performed. Although the fixation target presenting means for guiding the line of sight to an arbitrary position has been described, the alignment reference marks ML and MR are also applied to the apparatus that presents the fixation target 23a at a position fixed according to the left and right eyes or the imaging magnification. The same effect can be obtained by displaying at different positions according to the fixation target position.
[0027]
FIG. 10 shows a second embodiment, which is a mydriatic fundus camera in which a photographer observes an eye to be examined with the naked eye through a finder. The same reference numerals as those 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 and a finder lens 43 are arranged to constitute a finder optical system. Further, a lens 44, a mirror 45, a second liquid crystal element 46, and a second liquid crystal illumination means 47 are sequentially arranged in the right reflection direction, which is the transmission direction of the half mirror 41 when viewed from the photographer e. The reference target projection optical system is configured, and the output of the second liquid crystal illumination means 47 is connected to the liquid crystal control means 26.
[0028]
The fundus illumination means C constantly emits visible light, and the fundus Er is constantly illuminated by the visible light. The photographer can observe the reflected images of the alignment targets AL and AR from the fundus Er illuminated by the steady light and the cornea Ec of the eye E through the viewfinder optical system.
[0029]
The second liquid crystal element 46 is controlled by the liquid crystal control means 26, and forms a light transmission portion having a reference target shape as in the first embodiment. The reference marks ML and MR are illuminated by the second liquid crystal illumination means 47, reflected by the mirror 45, and imaged by the lens 44 near the field lens. The photographer can use the finder lens 43 to observe the images of the reference marks ML and MR, the fundus image, and the reflected images of the alignment targets AL and AR.
[0030]
Accordingly, the photographer e observes the fundus image through the viewfinder lens 43 and aligns the reflected images of the alignment targets AL and AR so as to match the reference marks ML and MR. The same effect as the example can be obtained. Although two liquid crystal display means are used in the second embodiment, one liquid crystal display means is partially used for projecting a fixation target to a subject and for projecting reference marks ML and MR to a photographer. You may use it properly.
[0031]
【The invention's effect】
As described above, the ophthalmologic apparatus according to the present invention performs positioning so that the reflected image of the target luminous flux matches the reference mark while observing the fundus image, even when photographing the periphery of the eye to be examined. The imaging optical axis can be accurately positioned at the center of the pupil, and the imaging optical axis can be accurately aligned with respect to the center of the pupil for alignment. The left and right stereoscopic images with little difference can be captured, and a captured image having a good stereoscopic effect can be obtained.
[0032]
In addition, the ophthalmologic apparatus according to the present invention displays a reference mark for alignment at a different position corresponding to the fixation target position, and a reflected image of the target luminous flux projected on the anterior segment of the eye to be examined at that position. By aligning the positions of the eyes, 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. Therefore, the right and left three-dimensional images with a small difference in the amount of light can be photographed, and a photographed image having a good three-dimensional effect can be obtained even for an eye to be examined having a small pupil diameter.
[Brief description of the drawings]
FIG. 1 is a perspective view of a fundus camera of a first embodiment.
FIG. 2 is a configuration diagram.
FIG. 3 is a front view of an auxiliary visual target.
FIG. 4 is an explanatory diagram of a fixation target.
FIG. 5 is an explanatory diagram of a display screen in the case of photographing centering on the macula.
FIG. 6 is an explanatory diagram of a display screen during 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 during stereoscopic shooting.
FIG. 9 is an explanatory diagram of a left display screen.
FIG. 10 is a configuration diagram of a fundus camera of a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base 5 Measuring part housing | casing 6 Television monitor 7 Operation means 8 Vertical movement switch 9 Digital camera 12 Perforated mirror 12a Shooting aperture 15 Switching mirror 17L, 17R Optical fiber 18L, 18R Target illumination light source 22 Imaging means 23 Liquid crystal element 25 Image processing unit 26 Liquid crystal control means 27 CPU
28 Control means 29 Shooting mode selection switch 30 Fixation target movement switch 31 Shooting switch

Claims (2)

Fixation target presenting means for presenting a fixation target for guiding the gaze of the subject to the eye ;
Fundus observation means for observing the fundus image of the eye to be examined;
Alignment assisting means for guiding the reflected image from the cornea when the target luminous flux is projected onto the anterior segment of the eye to be examined to the fundus oculi observation means as a plurality of alignment targets having different shapes ;
Display control means for displaying a plurality of reference marks on the fundus oculi observation means for aligning the plurality of alignment targets at positions corresponding to the position of the fixation target presented by the fixation target presentation means; Have
The display control means displays the shape of the plurality of reference marks on the fundus oculi observation means in correspondence with the shape of the alignment target . Fixation target presenting means for presenting a fixation target for guiding the gaze of the subject to the eye;
Fundus observation means for observing the fundus image of the eye to be examined;
An alignment assisting means for guiding the reflected image from the cornea when projecting the target luminous flux onto the anterior segment of the eye to be examined as a plurality of alignment targets to the fundus oculi observation means;
Display control means for displaying a plurality of reference marks on the fundus oculi observation means for aligning the plurality of alignment targets at positions corresponding to the position of the fixation target presented by the fixation target presentation means; Have
The ophthalmologic apparatus, wherein the plurality of alignment targets can be selected, and the display control unit displays a reference mark corresponding to the selected alignment target on the fundus observation unit .

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