JPH10314120A - Fundus camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To switch the function of a pupil spreading type or a pupil non- spreading type by switching light emitting wavelength from a light source for observation to an infrared ray or a visible ray, an illuminating system to an illuminating system of a pupil non-spreading type or that of a pupil spreading type and the light emitting wavelength of a light source for a working distance to the infrared or visible ray. SOLUTION: At the time of using as the pupil spreading type, a filter F1, lens systems L3, L4 transmitting a visible ray, and mirrors M5 and M7 are inserted to an optical path by an actuator to turn on a visible light emitting diode LED 1 to turn on the visible light emitting diode L3 of a light source for the working distance. On the other hand, at the time of using as the pupil non-spreading type, an infrared passing filter F1', lens systems L3' and L4' are inserted to the optical path to detach the mirrors M5 and M7 from within the optical path and to turn on an infrared lay emitting diode LED2 to turn on an infrared ray emitting diode LED4 of the light source for the working distance. In either case, LED which is not under use is kept in an off state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fundus camera, and more particularly to a fundus camera in which a mydriatic retinal camera and a non-mydriatic retinal camera are integrated and the functions of the binocular fundus cameras can be switched.

[0002]

2. Description of the Related Art Generally, a mydriatic retinal camera and a non-mydriatic retinal camera are known as cameras for imaging a fundus image by forming reflected light from the fundus illuminated by light from a light source. I have. The mydriatic retinal camera mainly uses a visible light source, can capture a wide angle of view, and has a tilt mechanism of the camera itself to enable capturing of every corner of the fundus. In addition, since observation and alignment are performed using visible light, a fundus camera having a working distance function for alignment also uses visible light as a light source for the working distance. The drawback of the mydriatic retinal camera is that it is necessary to dilate the eye to be measured, which imposes a great burden on the subject.

On the other hand, a non-mydriatic retinal camera uses infrared light as a light source, so it is not necessary to dilate the eye to be examined. The focus is controlled by projecting an infrared light focus index onto the fundus without using visible light for focusing. Further, since observation and alignment are performed by infrared light, a fundus camera having a function of working distance for alignment also uses infrared light as a light source of the working distance.

[0004]

In the conventional retinal camera, the above functions are realized as a mydriatic retinal camera or a non-mydriatic retinal camera, respectively. Did not exist.

It is an object of the present invention to provide a fundus camera having mydriatic and non-mydriatic functions and capable of switching between these functions by simple means.

[0006]

In order to solve this problem, the present invention irradiates light from an observation light source to the fundus of an eye to be inspected via an illumination system, and converts reflected light from the fundus into an image forming optical system. In a fundus camera that forms an image through a system and observes the fundus, a means for switching the emission wavelength of the observation light source between visible light and infrared light, and an illumination system for removing flare are different from a mydriatic illumination system. Means for switching to a mydriatic illumination system, and means for switching the emission wavelength of the working distance light source to illuminate the working distance index to visible light and infrared light,
Means for switching the fundus camera between a mydriatic function and a non-mydriatic function; when the function is switched to a non-mydriatic function, the emission wavelength from the observation light source is changed to infrared light. In the case where the illumination system is switched to a non-mydriatic illumination system and the emission wavelength of the working distance light source is switched to infrared light, while the function is switched to a mydriatic function,
A configuration was adopted in which the emission wavelength from the observation light source was switched to visible light, the illumination system was switched to a mydriatic illumination system, and the emission wavelength of the working distance light source was switched to visible light.

In order to switch between the mydriatic type and the non-mydriatic type, it is necessary to switch the emission wavelength of the observation light source between visible light and infrared light. In the present invention, this is realized by using a light source including, for example, visible light and infrared light, and inserting a visible light transmitting filter or an infrared light transmitting filter into the optical path in front of the observation light source. Further, the illumination system for removing flare is switched between a mydriatic illumination system and a non-mydriatic illumination system in conjunction with the switching between the two functions. The focus detection is switched between visible light and infrared light, and the finder system is switched between the eyepiece and the CCD camera in conjunction with the focus detection.

Further, the light source for illuminating the working distance index for alignment is switched between visible light and infrared light in conjunction with the switching between the two functions.

In this way, since both the mydriatic and non-mydriatic functions can be realized by a simple switching operation, a space-saving fundus camera with good usability can be obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings.

FIG. 1 shows a fundus camera according to the present invention.
A lamp LA, which is a light source for observation that generates visible light including infrared light, is disposed at the center of curvature of the spherical mirror M1, and light emitted from this lamp is transmitted through a condenser lens L1,
After passing through the filter F1 and the condenser lens L2, the light is reflected by the total reflection mirror M2,
3, after being reflected by a perforated total reflection mirror M3 having a hole at the center, and passing through an objective lens L5, the eye E to be examined.
From the pupil Ep of the eye.

The reflected light from the fundus Er is received again from the pupil Ep via the objective lens L5, and the perforated total reflection mirror M
The light passes through the focusing lens L6 and the imaging lens L7 through the third hole, and enters the mirror M4. The light reflected by the mirror M4 is reflected by the mirror M5 and observed by the examiner S through the eyepiece L8. The mirror M5 is configured so that it can be removed from the optical path. When the mirror M5 is removed from the optical path, the light beam reflected by the mirror M4 is imaged on the CCD via the lens L9 after being reflected by the mirror M6. Is done.

Further, light sources LED1 and LED2 for focus detection are provided, and light from these light sources passes through a mirror M7, a lens L10, a mirror M8, and a lens L11 between a perforated total reflection mirror M3 and an imaging lens L6. Is incident on the mirror M9 disposed at the position, and a spot image for focusing is formed on the fundus via the perforated total reflection mirror M3 and the lens L5.

For photographing a fundus image on the film F, a strobe SR as a photographing light source is disposed between the filter F1 and the lens L2. When photographing a fundus image on the film F, the mirror M4 is removed from the optical path, and the fundus image is guided onto the film F.

In the fundus camera of the present invention, various switching operations are performed so that the functions of the mydriatic retinal camera and the non-mydriatic retinal camera can be implemented.

First, the emission wavelength of the light source for illuminating and observing the eye E is switched. In the non-mydriatic type,
The fundus must be illuminated with infrared light, and since the lamp LA contains visible light, it is necessary to cut off the visible light from the lamp LA. For this purpose, a filter F1 that transmits only visible light and a transmission filter F1 ′ that transmits only infrared light are switched. In the case of a mydriatic type, the filter F1
However, in the case of the non-mydriatic type, the filters F1 'are respectively inserted in the optical paths.

Next, in order to remove flare, the illumination system lenses are switched to mydriatic lenses L3, L4 and non-mydriatic lenses L3 ', L4'. As a result, switching between the mydriatic illumination system and the non-mydriatic illumination system is performed.

Further, for focus detection, a focus index, that is, a focusing spot is irradiated on the fundus. In the case of the mydriatic type, visible light is used. In the case of the non-mydriatic type, infrared light is used. The focus index of visible light and the focus index of infrared light are switched according to switching between the mydriatic type and the non-mydriatic type. For this purpose, the mirror M7 is inserted into or removed from the optical path. The light source for focus detection is a light-emitting diode L that emits visible light in a mydriatic type.
If the ED1 is a non-mydriatic type, the infrared light emitting diode L
Since the ED2 is used, the mirror M7 is inserted into the optical path in the mydriatic type, whereas the mirror M7 is removed from the optical path in the non-mydriatic type. In this way, the light from these light sources is applied to the fundus via the mirrors M8 and M9, and a spot image, which is a focus index of infrared light or visible light, is projected on the fundus.

In the mydriatic type, a fundus image is observed through an eyepiece L8, and a focusing operation is performed. In the non-mydriatic type, the mirror M5 is removed from the optical path, and C
Focus detection is performed via a spot image formed on a CD. In either type, focusing is performed by the examiner S adjusting the focusing lenses L6 and L11 while observing with an eyepiece or while looking at the image formed on the CCD.

Also, the working distance light source 17
, An index for alignment (in the present embodiment, one end utilizes the end face of the optical fiber OF disposed on the perforated total reflection mirror M3) and a light source for illuminating the index. The light source is provided with a mydriatic visible light emitting diode LED3 and a non-mydriatic infrared light emitting diode LED4.
D3 or LED4 is selected.

In the case of the mydriatic type, the LED 3 is lit, and in the case of the non-mydriatic type, the LED 4 is lit, illuminating the end face of the optical fiber OF via the lens L20. The illuminated light is emitted from the other end surface (which serves as an index), and is projected onto the cornea of the eye E through the objective lens L5. In the case of the mydriatic type, the light reflected by the cornea is again the objective lens L5, the perforated total reflection mirror M3, and the lens L
6, L7, mirrors M4 and M5, and the lens L8 are observed by the examiner S.

On the other hand, in the case of the non-mydriatic type, the objective lens L
5. The examiner S via the perforated total reflection mirror M3, the lenses L6 and L7, the mirrors M4 and M6, the lens L9, and the CCD.
Observed by This optical fiber OF
Is located at a position where the subject is in focus when the working distance (working distance) between the subject and the fundus camera becomes an appropriate distance.

FIGS. 3 and 4 show examples of the means for switching the working distance light source. The example in FIG. 3 is an example in which the LED 3 and the LED 4 are switched by moving the mirror M10 into and out of the optical path.
FIG. 5 shows a method of switching by moving the LEDs 3 and 4 themselves, and FIG. 5 shows a method of switching by bringing the LEDs 3 and 4 as close as possible and electrically turning them on and off. In either method, the LED not used is turned off.

Next, the wavelength of the working distance light source will be described. In the case of the mydriatic type, since the observation is performed with an eyepiece using visible light, the light source for the working distance for alignment also uses visible light.
In the present embodiment, a region having high relative luminosity, that is, λ = 520 nm to 560 nm, is used in the visible light. Thereby, the light amount of the light source can be reduced, and the cost of the LED can be reduced. In the case of the non-mydriatic type, since the observation is performed by infrared light, the infrared light is also used as the working distance light source for alignment. In the present embodiment, of the infrared light, λ = 700 nm to 900 n
m is used. If the shorter wavelength side is used, the subject starts to feel the light of the working distance light source, which adversely affects the natural mydriasis. Further, if a longer wavelength side is used, the influence of the chromatic aberration of the optical system starts, and a problem arises in that alignment is performed at different positions in visible light and infrared light.

The reason why the LED is used as the working distance light source is as follows. When the alignment is completed and the fundus photography is started, this working distance light source is a harmful ray and needs to be turned off.
When a halogen lamp or the like is used, the light is not turned off instantaneously even when the power is turned off. For this reason, the working distance indices overlap in the fundus image. Therefore, this problem can be avoided by using an LED with good on / off responsiveness as a working distance light source.

In this manner, the switching between the mydriatic type and the non-mydriatic type is performed. However, since all of these switchings must be performed at the same time, and must be performed simply and reliably, FIG. As described above, as shown in the schematic blocks 12, 13, 15, 16, and 17 via the actuator 11 such as a rotary solenoid which is turned on and off by the switch 10 for switching between the mydriatic type and the non-mydriatic type, the filters F1 and F1 are illustrated. 'And lens systems L3, L4 and L3',
L4 'is switched, and mirror M5,
M7 is inserted into and removed from the optical path. Switching at the time of focus detection is performed by switching the light emitting diodes LED1 and LED2 with the switch 10 as shown in block 14.
One of them should be turned on according to the switching of.
As shown in block 17, the working distance light source also switches between the light emitting diodes LED3 and LED4, and turns off the unused LED.

Next, the operation of the fundus camera configured as described above will be described.

First, when used as a mydriatic type, the switch 10 is used to switch to the mydriatic type. As a result, the actuator 11 operates, and the filter F1, the lens system L
3, L4 and mirrors M5, M7 are inserted in the optical path. Also, the visible light emitting diode LED1 is turned on, and the visible light emitting diode L3 serving as a working distance light source is turned on.
Is selected and turned on. The fundus Er is illuminated with visible light by the filter F1 that allows visible light to pass therethrough, while the visible light emitting diode L for working distance is used.
Alignment is performed based on the index projected by the ED3, a spot image formed by the visible light emitting diode LED1 is observed by the examiner S, and focusing is performed by adjusting the focusing lens L6. In the mydriatic type, it becomes possible to observe or photograph the fundus using the examiner S or the film F.

On the other hand, when used as a non-mydriatic type,
The actuator 11 is turned off, the infrared-pass filter F1 'and the lens systems L3' and L4 'are inserted into the optical path, and the mirrors M5 and M7 are separated from the optical path. Also,
The infrared light emitting diode LED2 is turned on, and the infrared light emitting diode LED4 as the working distance light source is selected and turned on. In any case, the unused LED is turned off.

The fundus Er is illuminated with infrared light by the filter F1 'that allows infrared light to pass therethrough, while alignment is performed based on the index projected by the infrared light emitting diode LED4 for working distance, and red Focusing is performed by a spot image formed on the CCD by the outside light emitting diode LED2. With the non-mydriatic type, a wide angle of view cannot be obtained as with the mydriatic type, but the burden on the patient can be reduced to enable fundus observation and imaging. In addition, a method is also conceivable in which an image is taken by a non-mydriatic type, and if there is any doubt, a mydriatic agent is instilled and an image is taken by the mydriatic type.

[0031]

As described above, according to the present invention, means for switching the fundus camera between a mydriatic function and a non-mydriatic function is provided. Changes the emission wavelength from the observation light source to infrared light,
The illumination system for removing flare is switched to a non-mydriatic illumination system, and the light source for illuminating the alignment index is switched to infrared light. When switching to the mydriatic function, the wavelength of light emitted from the observation light source is changed to visible light, the illumination system for removing flare is changed to a mydriatic illumination system, and the alignment index is illuminated. Switch to visible light. With such a configuration, both mydriatic and non-mydriatic functions can be realized by a simple switching operation, and a fundus camera with good usability and space saving is provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a schematic configuration of a fundus camera of the present invention.

FIG. 2 is a block diagram showing a configuration for switching between mydriatic and non-mydriatic functions.

FIG. 3 is a configuration diagram illustrating an example of a switching unit for a working distance light source.

FIG. 4 is a configuration diagram showing another example of a switching means for a working distance light source.

FIG. 5 is a configuration diagram showing still another example of a switching means for a working distance light source.

[Explanation of symbols]

 LA lamp F1 Visible light transmitting filter F1 'Infrared transmitting filter E Examinee eye S Examiner LED1 Visible light emitting diode LED2 Infrared light emitting diode LED3 Visible light emitting diode LED4 Infrared light emitting diode

Claims (5)

[Claims] 1. A fundus camera for irradiating light from an observation light source to a fundus of an eye to be examined via an illumination system and forming an image of reflected light from the fundus via an imaging optical system to observe the fundus. Means for switching the emission wavelength from the light source for visible light and infrared light, means for switching the illumination system for removing flare between mydriatic and non-mydriatic illumination systems, and illumination for the working distance index Means for switching the emission wavelength of the working distance light source between visible light and infrared light, and means for switching the fundus camera between a mydriatic function and a non-mydriatic function. When switching to the function, the emission wavelength from the observation light source is switched to infrared light, the illumination system is switched to a non-mydriatic illumination system, and the emission wavelength of the working distance light source is switched to infrared light. Mydriatic When the function is switched to the above function, the emission wavelength from the observation light source is switched to visible light, the illumination system is switched to the mydriatic illumination system, and the emission wavelength of the working distance light source is switched to visible light. Fundus camera. 2. An optical fiber for guiding an emission wavelength of a working distance light source to an illumination optical system is provided.
The fundus camera according to claim 1, wherein an end face of the optical fiber is used as a working distance index. 3. The infrared light emission wavelength when the emission wavelength of the working distance light source is switched to infrared light is in the range of λ = 700 nm to 900 nm. Fundus camera. 4. The fundus according to claim 1, wherein an emission wavelength of the visible light when the emission wavelength of the working distance light source is switched to a visible light is in a range of λ = 520 nm to 560 nm. camera. 5. The fundus camera according to claim 1, wherein the working distance light source is switched to an infrared light emitting diode or a visible light emitting diode.