JPH09122078A - Fundus camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow alleviating of pains inflicted on a subject during the observation while simplifying the structure of an insertion/removal mechanism by arranging an exciter filter to have a wavelength characteristic of transmitting infrared rays. SOLUTION: An observation/photographing system 51 is roughly constituted of a common optical system 52, an observation system 53 and a photographing system 54. A lighting system 50 has a concave mirror 55, a halogen lamp 56, a condenser lens 57, a infrared transmission filter 58, a circular xenon lamp 59, a ring stop 60, a relay lens 61, a black spot plate 62, focusing index mechanism 63 and a relay lens 64. The infrared transmission filter 58 serves to transmit infrared rays with the wavelength thereof exceeding about 830nm and the exciting filter 67 serves to transmit illumination light as photographing light with the wavelength of 450nm to 520nm and illumination light as infrared rays with the wavelength exceeding 820nm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a fundus camera capable of general photography and fluorescence photography.

[0002]

2. Description of the Related Art Conventionally, as a fundus camera, one capable of performing both general photography and visible fluorescence photography is known. This fundus camera is a mydriasis type, and FIG. 1 is an optical diagram showing an example of this kind of fundus camera. In FIG. 1, 1 is an illumination system and 2 is a photographing system. The illumination system 1 is roughly composed of a concave reflecting mirror 3, a halogen lamp 4, a condenser lens 5, a xenon lamp 6, a condenser lens 7, a ring diaphragm 8, a total reflection mirror 9, a relay lens 10, a black dot plate 11, and a relay lens 12. There is. The photographing system 2 includes an objective lens 13, a perforated mirror 14, an aperture stop 15, and a focusing lens 1.
6, imaging lens 17, quick return mirror 18, 1
9, a TV camera 2 having a field lens 20, a reflection mirror 21, a relay lens 22, and an area CCD 23
4, a processing circuit 25 with a built-in memory, and a monitor device 26. The quick return mirror 19 is provided behind the quick return mirror 18, and the shutter 27 and the 35 mm film 2 are provided behind the quick return mirror 19.
8 is provided, and an eyepiece optical system including a field lens 29, a reflection prism 30, and an eyepiece lens 31 is provided in front of the quick return mirror 19 in the reflection direction. The illumination system 1 is provided with an insertion / removal mechanism 32 for adjusting the amount of illumination light and an insertion / removal mechanism 33 for an exciter filter between the total reflection mirror 9 and the relay lens 10. The insertion / removal mechanism 32 is ND
The filter 34, the dummy filter 35, and the solenoid 36 are roughly configured, and the insertion / removal mechanism 33 is generally configured by an exciter filter 37, a dummy filter 38, and a solenoid 39. The photographing system 2 is provided with an insertion / removal mechanism 40 for a barrier filter between the aperture stop 15 and the focusing lens 16. The insertion / removal mechanism 40 is generally composed of a barrier filter 41, a dummy filter 42, and a solenoid 43.

In this fundus camera, the dummy filters 35 and 38 are inserted into the optical path of the illumination system 1 during observation, and the illumination light from the halogen lamp 4 illuminates the fundus Ef of the eye E as ring slit light. The reflected light from the fundus Ef is guided to the eyepiece optical system through the objective lens 13, the hole portion 14a of the perforated mirror 14, the aperture stop 15, the focusing lens 16, the imaging lens 17, and the quick return mirror 19. The examiner performs alignment operation and focusing operation while observing the fundus image through the eyepiece optical system.

Next, when a photographing switch (not shown) is operated, photographing is performed. When recording a fundus image on the 35 mm film 28 in the film photographing mode, the xenon lamp is in the state shown in FIG. 6 is emitted, and the quick return mirror 19 is flipped up in the direction of the arrow to shoot. Further, when an image is recorded in the color photographing mode, when a photographing switch (not shown) is operated, the solenoid 36 is driven, the ND filter 34 is inserted into the optical path of the illumination system 1, and the xenon lamp 6 emits light. On the other hand, the quick return mirror 18 is switched in the direction indicated by the arrow to illuminate the fundus Ef with the dimmed ring slit light, the reflected light from the fundus Ef is guided to the television camera 24, and the fundus image is processed. The fundus image recorded in the memory 25 is instantly reproduced and the review image is displayed on the screen 26 a of the monitor device 26. Here, the ND filter 34 is not inserted in the film photographing mode, and the ND filter 34 is inserted in the color photographing mode because the sensitivity of the television camera 24 is much higher than the sensitivity of the film. This is because good image recording cannot be obtained if shooting is performed with the same light amount as in the shooting mode. In the visible fluorescence photography mode,
A fluorescent agent is intravenously injected in advance to the subject, the exciter filter 37 is inserted into the optical path of the illumination system 1, the barrier filter 41 is inserted into the imaging system 2, observation is performed by the eyepiece optical system, and the imaging switch is operated. The xenon lamp 6 emits light. When the fundus image is recorded on the 35 mm film 28 as the film photographing mode, the quick return mirror 19 is flipped up in the arrow direction to perform photographing,
On the other hand, when performing image recording, the quick return mirror 18 is switched in the direction indicated by the arrow. The illumination light of the xenon lamp 6 passes through the exciter filter 37 to become excitation light, and the excitation light excites the fluorescent agent flowing through the blood vessels of the fundus to generate visible fluorescence. The excitation light reflected by the fundus Ef and the visible fluorescence generated from the fundus Ef are guided to the barrier filter 41, and the excitation light is excited by the barrier filter 41.
Is blocked by the barrier filter 41, and the visible fluorescence that has passed through the barrier filter 41 is reflected by the quick return mirror 18 and guided to the television camera 24. It is displayed on the screen 26a. No non-mydriatic type has a configuration capable of performing visible fluorescence imaging.

[0005]

By the way, in this conventional fundus camera, when the fundus is observed, the fundus E
Since f is illuminated, it gives glare to the subject and is painful to the subject. In particular, in the case of color photography, while illuminating the eye to be examined with illumination light in the entire visible wavelength range, when observing in the fluorescence photography mode, the transmission band of the exciter filter inserted in the illumination system 1 is 450 nm to 520 nm, The fundus oculi Ef are illuminated with illumination light in a wavelength band with low human relative luminous efficiency. That is, color photography causes more pain to the subject than observation in the fluorescence photography mode. Further, since it is necessary to provide both the light amount adjusting insertion / removal mechanism and the exciter filter insertion / removal mechanism, the insertion / removal mechanism becomes complicated.

The present invention has been made in view of the above circumstances, and provides a fundus camera capable of simplifying the structure of the insertion / removal mechanism and reducing the pain to the subject during observation.

[0007]

In order to solve the above-mentioned problems, the fundus camera according to claim 1 of the present invention is provided with an exciter filter for visible fluorescence photography in the illumination system so that it can be inserted and removed, and the photography system. In a fundus camera capable of inserting and removing a barrier filter for visible fluorescence photography and capable of a general photography mode and a visible fluorescence photography mode, the exciter filter has a wavelength characteristic of transmitting infrared light.

The fundus camera according to claim 2 of the present invention is
The exciter filter in the color photographing mode is inserted in the optical path of the illumination optical system during observation of the fundus,
Moreover, it is retracted from the optical path of the illumination optical system when photographing the fundus in the mode.

The fundus camera according to claim 3 of the present invention is
An ND filter is inserted in the optical path in synchronization with the withdrawal of the exciter filter from the optical path.

The invention according to claim 4 of the present invention is characterized in that a finder optical system is provided so as to be branched from the photographing system, and observation during visible fluorescence photographing is performed using the finder optical system.

[0011]

According to the inventions of claims 1 to 4, since the exciter filter has a characteristic of transmitting infrared light, the exciter filter remains inserted in the optical path of the illumination system. The fundus can be observed by using the illumination light that has passed through.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the invention relating to the fundus camera of the present invention will be described below with reference to the drawings.

(Embodiment 1) In FIG. 2, 50 is an illumination system and 51 is an observation / photographing system. The observation / photographing system 51 is roughly configured by a common optical system 52, an observation system 53, and a photographing system 54. The illumination system 50 includes a concave mirror 55, a halogen lamp 56, a condenser lens 57, an infrared transmission filter 58,
It has an annular xenon lamp 59, a ring diaphragm 60, a relay lens 61, a black dot plate 62, a focusing index mechanism 63, and a relay lens 64. The ring diaphragm 60 is substantially conjugate with the pupil of the eye E to be inspected, and the black spot plate 62 is substantially conjugate with the aperture diaphragm 67B when the objective lens is considered as a reflecting surface. An insertion / removal mechanism 65 is provided between the ring diaphragm 60 and the relay lens 61, and the insertion / removal mechanism 65 is roughly composed of an ND filter 66, an exciter filter 67, and a solenoid 68. A stepping motor may be used instead of the solenoid 68. Focusing index mechanism 63 (Japanese Patent Publication 61
-91 gazette), as shown in FIG.
A, condenser lens 65A, infrared transmission filter 66
A, index 67A, relay lens 68A, glass plate 69A
Approximately. The glass plate 69A has a dichroic mirror portion 69a, and the dichroic mirror portion 6a.
9a transmits visible light and reflects infrared light. The focusing index mechanism 63 is moved in the optical axis direction in conjunction with a focusing lens described later.

The infrared transmission filter 58 plays a role of transmitting infrared light having a wavelength of about 830 nm or more, as shown in FIG.
The exciter filter 67 has a wavelength of 450 as shown in FIG.
The illumination light and the wavelength of 82 from the wavelength of 520 nm to the wavelength of 520 nm
It has a role of transmitting the illumination light as infrared light of 0 nm or more.

The shared optical system 52 comprises an objective lens 65B, a perforated mirror 66B, an aperture stop 67B, a dichroic mirror 68B, a focusing lens 69, an imaging lens 70, and a dichroic mirror 71. The shared optical system 52 is provided with an alignment optical system 72.
The alignment optical system 72 includes an alignment light source 7
3, a light guide 74, a mirror 75, a two-hole diaphragm 76, and a relay lens 77. The two-hole aperture 76 has a pair of holes 76a and 76a as shown in FIG. The alignment light source 73 emits near-infrared light having a wavelength of 760 nm, the near-infrared light incident on the light guide 74 is emitted from its exit end, and the near-infrared light emitted from its exit end is reflected by the mirror 75. Relay lens 7 through the holes 76a, 76a.
7, the relay lens 77 once forms an image of the exit end of the light guide 74 at the central position X of the hole portion 66a of the perforated mirror 66B. The dichroic mirror 68B is shown in FIG.
As shown in FIG. 5, it plays a role of transmitting about 30% of near-infrared light having a wavelength of 760 nm and totally transmitting light in other wavelength regions.

The pair of alignment light fluxes, which are once imaged at the central position X of the hole 66a, are guided to the cornea C of the eye E to be examined through the objective lens 65B. Here, when the working distance W from the eye E to the apparatus main body and the position of the apparatus main body in the vertical and horizontal directions with respect to the eye E are proper, the pair of alignment light beams is used to connect to a position half the center of the corneal curvature. Image projected. When the working distance W from the eye E to be inspected is deviated from the proper position, the alignment image based on the pair of alignment light beams is projected separately at a position half the center of the corneal curvature of the cornea C. To be done. The alignment reflected light beam reflected by the cornea C is imaged at the conjugate position R with the fundus oculi Ef by the objective lens 41 when the working distance W is appropriate. The alignment reflected light flux imaged at the position R passes through the hole 66a and is guided to the observation system 53 similarly to the light flux forming the fundus image.

The observation system 53 includes a field lens 78, a reflection mirror 79, a relay lens 80, a television camera 82 having an area CCD 81, and a processing circuit 8 having a built-in memory.
3. It consists of a TV monitor 84. The photographing system 54 includes a prism 85 with a field lens, an insertion / removal mechanism 86, a relay lens 87, a television camera 89 having an area CCD 88, a processing circuit 90 having a built-in memory, and a television monitor 91. The insertion / removal mechanism 86 is roughly composed of a dummy filter 92 and a barrier filter 93.
The barrier filter 93 has a transmission characteristic of transmitting light having a wavelength of 530 nm to 640 nm as shown in FIG. In addition,
The dichroic mirror 71 has a wavelength 70 as shown in FIG.
It has a transmission characteristic of transmitting light having a wavelength of 0 nm or less and reflecting infrared light having a wavelength of 700 nm or more.

An exciter filter 67 is inserted in the optical path of the illumination system 50 for observation in either the color photographing mode or the visible fluorescence photographing mode, and the fundus Ef has a wavelength of 800.
Illuminated by infrared light above nm. The reflected light from the fundus Ef is the objective lens 65B, the hole 66a of the perforated mirror 66B, the aperture stop 67B, and the dichroic mirror 68.
It is guided to the dichroic mirror 71 through B, the focusing lens 69, and the imaging lens 70, and this dichroic mirror 7
It is reflected by 1 and is imaged in the air in the vicinity of the field lens 78. The fundus image EM formed in the air is formed on the television camera 82 via the reflection mirror 79 and the relay lens 80, and the fundus image EM is displayed on the screen 84a of the monitor device 84. Similarly, as shown in FIGS. 10A and 10B, the television camera 82 receives the alignment image AI, and the alignment image AI is obtained when the working distance W from the eye E to be inspected to the apparatus main body is at an appropriate position. As shown in FIG. 10 (A), they are displayed in conformity with each other, and when the working distance W from the eye E to the apparatus main body is not in the proper position, they are displayed separately as shown in FIG. The alignment of the apparatus main body with respect to the eye E can be performed while observing the separation / non-separation of the alignment image AI.

An index image 67 'based on the focusing index mechanism 63 is displayed on the screen 84a. Infrared light transmission is cut off in the reflection area of the dichroic mirror portion 69a, so that the area 69a 'other than the area where the index image 67' is formed becomes a dark part, and the index image 67 'appears to float. The focus can be adjusted while looking at the index image 67 '.

An exciter filter 67 is inserted in the optical path of the illumination system 50 during observation regardless of whether the color photographing mode or the visible fluorescence photographing mode is selected. When shooting in the color shooting mode, the ND filter 66 is inserted in place of the exciter filter 67. It should be noted that the exciter filter 67 is maintained in the optical path of the illumination system 54 as it is during photographing in the visible fluorescence photographing mode. As described above, since the exciter filter 67 is selected in both the observation in the color photographing mode and the observation in the visible fluorescence photographing mode, the insertion / removal mechanism is simplified as compared with the conventional fundus camera. Further, a dummy filter 92 is inserted in the optical path of the photographing system 54 during observation and photographing in the color photographing mode, and a barrier filter 93 is inserted during observation and photographing in the visible fluorescence photographing mode. Pressing the shooting switch in the color shooting mode causes the xenon tube 5
9 is emitted, the fundus Ef is illuminated by visible light, and the fundus image by the visible light passes through the dichroic mirror 71 and is received by the television camera 89, image recording is performed, and the screen 91a of the monitor device 91 is photographed. A color image that is a fundus image is displayed. When the photographing switch is pressed in the visible fluorescence photographing mode, the xenon tube 59 emits light, the fundus Ef is illuminated by the excitation light, and the fundus image by the excitation light and the visible fluorescence passes through the dichroic mirror 71 and is guided to the barrier filter 93. Then, only the fundus image by the visible fluorescence passes through the barrier filter 93 and the television camera 89.
, And thus a visible fluorescence image is recorded.

Table 1 below shows the conditions for combining the filters.

[0022] FIG. 11 shows a modified example of the first embodiment. In this embodiment, the insertion / removal mechanism 86 is arranged between the dichroic mirror 68B of the shared optical system 52 and the focusing lens 69. . In this case, since infrared light is used for observation in the visible fluorescence photographing mode in the optical path of the shared optical system 52, the dummy filter 9 is used for observation in the visible fluorescence photographing mode.
2 is inserted, and the barrier filter 93 is inserted at the time of photographing. When the transmission characteristics of the barrier filter 93 are in the infrared wavelength range as shown in FIG. 12, the barrier filter 93 may be left inserted in the optical path of the shared optical system 52 during observation in the visible fluorescence imaging mode. In this case, since the infrared cut filter is usually attached to the television camera 89 for visible image capturing, the visible fluorescent image is not deteriorated.

(Embodiment 2) FIG. 13 shows that observation is performed by infrared light in the color photographing mode and visible fluorescence in the visible fluorescence photographing mode. Description will be given with the same reference numerals.

In the second embodiment, the infrared transmission filter 58 is used.
Can be inserted into and removed from the optical path of the illumination system 50, and the infrared transmission filter 58 is inserted in the optical path of the illumination system 50 instead of the infrared cut filter 94 when observing in the color imaging mode. Infrared cut filter 9 for observation
4 is inserted instead of the infrared transmission filter 58. Further, the shared optical system 52 is provided with a quick return mirror 71 'instead of the dichroic mirror 71, and the television camera 82 is one having sensitivity in the visible range as well.
Further, the barrier filter has the transmission characteristics shown in FIG.

The filter combination conditions at that time are the same as in Table 1. According to the second embodiment, since the infrared light is cut off, the contrast of the fluorescent image in the visible fluorescence photographing mode becomes good.

If the transmission characteristic of the barrier filter 93 is as shown in FIG. 8, the infrared cut filter 94 is used.
Need not be provided.

(Embodiment 3) FIG. 14 shows that the observation in the color photographing mode can be performed by the monitor device 84, and the observation in the visible fluorescence photographing mode can be performed by both the monitor device 84 and the eyepiece optical system. , Field lens 78
An infrared transmission / visible reflection dichroic mirror 95 is provided between the reflection mirror 79 and the reflection mirror 79, and as shown in FIG. 15, a relay lens 96, an image rotator 97, a reflection mirror 98, a relay lens 99, a focusing screen 100, and an eyepiece lens 101. It is possible to observe with a visible light in the visible fluorescence photographing mode through this.With this configuration, it is possible to confirm the fluorescence image with the finder, and it is particularly effective because it is possible to observe the fluorescence in the initial stage. is there.

[0028]

Since the fundus camera according to the first to fourth aspects of the present invention is constructed as described above, the structure of the insertion / removal mechanism can be simplified and the pain to the subject during observation can be reduced. The effect that it can be reduced is exhibited.

[Brief description of the drawings]

FIG. 1 is an optical diagram showing an overall configuration of a conventional fundus camera.

FIG. 2 is an optical diagram showing an overall configuration of a fundus camera of Example 1 of the present invention.

FIG. 3 is an optical diagram showing a configuration of a focus indexing mechanism.

FIG. 4 is a transmission characteristic diagram of the infrared transmission filter 58.

5 is a transmission characteristic diagram of an exciter filter 67. FIG.

FIG. 6 is a plan view of a two-hole diaphragm.

7 is a transmission characteristic diagram of the dichroic mirror 68. FIG.

FIG. 8 is a transmission characteristic diagram of the barrier filter 93.

9 is a transmission characteristic diagram of the dichroic mirror 71. FIG.

FIG. 10 shows a fundus image at the time of observation displayed on the screen of the monitor device, (A) shows a state in which the device body is at an appropriate working distance with respect to the eye, and (B) shows that with respect to the eye Indicates that the device body is not at the proper working distance.

FIG. 11 is an overall optical diagram showing a modified example of the first embodiment.

FIG. 12 is a diagram showing another example of the transmission characteristics of the barrier filter 93.

FIG. 13 is an optical diagram showing an overall configuration of a fundus camera of Embodiment 2 of the present invention.

FIG. 14 is an optical diagram showing an overall configuration of a fundus camera according to a third embodiment of the present invention.

15 is an optical diagram showing an example of the eyepiece optical system shown in FIG.

[Explanation of symbols]

 50 ... Illumination system 54 ... Imaging system 65 ... Inserting / removing mechanism 66 ... ND filter 67 ... Exciter filter 93 ... Barrier filter

Claims (4)

[Claims] 1. An exciter filter for visible fluorescence photography is removably provided in the illumination system, and a barrier filter for visible fluorescence photography is removably provided in the photography system, and a general photography mode and a visible fluorescence photography mode are provided. A fundus camera capable of performing the above-mentioned exciter filter having a wavelength characteristic of transmitting infrared light. 2. The exciter filter is inserted into the optical path of the illumination optical system when observing the fundus in a color photographing mode, and retracted from the optical path of the illumination optical system when photographing the fundus in the mode. Claim 1
The fundus camera described in. 3. The fundus camera according to claim 2, wherein an ND filter is inserted in the optical path in synchronization with the withdrawal of the exciter filter out of the optical path. 4. The fundus camera according to claim 1, wherein a finder optical system is provided so as to be branched from the photographing system, and observation during visible fluorescence photographing is performed using the finder optical system.