JP2000232961A - Fundus camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fundus camera capable of observing fundus oculi images on the same television monitor in either case of mydriatic photographing and non- mydriatic photographing, observing the fundus oculi images by visible light at the time of the mydriatic photographing and eliminating the possibility of the pupil contraction of an eye to be tested due to near sight by using an internal fixed visual mark at the time of the non-mydriatic photographing in the fundus camera capable of being shared for the mydriatic photographing and the non-mydriatic photographing. SOLUTION: This fundus camera is provided with an infrared light transmission mirror 95 freely insertably and detachably arranged in the optical path of a photographing optical system 53 for reflecting the visible light and transmitting infrared light and an internal fixed visual mark projection optical system G for projecting the internal fixed visual mark for guiding the line of sight of the eye E to be tested through the infrared light transmission mirror 95 to the eye E to be tested. Then, an infrared transmission filter 58 and an infrared cutting filter 94 as illumination switching means switch illumination light to the infrared light linked with the insertion to the optical path of the infrared light transmission mirror 95 and switch the illumination light to the visible light linked with the detachment from the optical path of the infrared light transmission mirror 95.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improvement in a fundus camera which can be used for both mydriatic and non-mydriatic photography.

[0002]

2. Description of the Related Art Conventionally, as a method of photographing the fundus, mydriasis is applied to a subject's eye to prevent miosis of the subject's eye and photograph the subject's eye. 2. Description of the Related Art Non-mydriatic imaging in which imaging is performed while waiting for the natural mydriasis of the subject's eye in a dark place is known. If a mydriatic agent is used here, miosis does not occur even when the subject's eye is irradiated with visible light, so both observation and imaging can be performed with visible light. In order to prevent miosis of the subject's eye, infrared light is used for observation and visible light is used for imaging. Therefore, in mydriatic photography and non-mydriatic photography, besides using or not using a mydriatic agent, in non-mydriatic photography, illumination with different wavelengths of visible light and infrared light is used as illumination light. They differ in the points they need.

At the beginning of non-mydriatic photography around 1975, these mydriatic photography and non-mydriatic photography were performed by dedicated machines such as a dedicated mydriatic photography machine and a non-mydriatic photography dedicated machine, respectively. The machine was mainstream. Subsequently, a common fundus camera (hereinafter, sometimes referred to as a common fundus camera) integrating these dedicated mydriatic machine and non-mydriatic dedicated machine was proposed (for example,
JP-A-58-89237, JP-A-58-1283
Reference). In these common fundus cameras, a visible cut filter (infrared transmission filter) is removably arranged in front of the observation illumination light source, and this visible cut filter is inserted during observation in non-mydriatic photography, such as mydriatic photography. In other cases, the visible cut filter is detached and the eye to be examined is irradiated with visible light.

[0004] However, when non-mydriatic photography is performed by these common fundus cameras, the fundus is observed with a television camera having sensitivity to infrared light. A method of observing the fundus with a visible finder provided in the camera is adopted. The reason for adopting such a configuration was that, in the case of non-mydriatic photography, the illumination light was infrared light, so observation with a visible finder was not possible. Therefore, in the case of mydriatic photography, observation with a visible finder was preferred, and a television camera having sensitivity to both infrared light and visible light was expensive.

As described above, in these common fundus cameras, the observation devices are provided separately according to the type of photographing, and therefore, the advantage of reducing the size of the devices by sharing the devices cannot be enjoyed. In addition, since it is necessary for the examiner to look into the mydriatic or non-mydriatic television cameras arranged at different positions according to the type of shooting, handling is complicated for those unfamiliar with the operation. .

In recent years, a fundus camera has been proposed in which the fundus image can be observed on the same television monitor in both mydriatic and non-mydriatic photography (for example, Japanese Patent Application Laid-Open No. 9-103409). reference.). However, in the fundus camera proposed in Japanese Patent Application Laid-Open No. 9-103409, a black-and-white television camera is used as a television camera, so that only a black-and-white observation image can be obtained even in mydriatic photography. is there.

On the other hand, a television camera having sensitivity to both infrared light and visible light is used as a television camera for observation.
This allows the fundus camera to be able to observe the fundus image on the same TV monitor for both mydriatic and non-mydriatic photography, and to allow the observation of a color fundus image during mydriasis photography. Proposals have been made (for example, see JP-A-8-66).
See No. 372. ).

[0008]

By the way, in a fundus camera, a fixation target for guiding the line of sight of the eye to be examined is usually provided. As the fixation target, in non-mydriatic photography, an internal fixation target is generally used, and the internal fixation target is projected from the inside of the apparatus to the subject's eye via the objective lens of the imaging optical system. . In mydriatic photography, a fixation lamp (external fixation target) attached to the tip of a flexible arm outside the apparatus is generally used.

[0009] This is because using an external fixation lamp during non-mydriatic photography may cause miosis by looking at the object nearby (near vision). This is because it is preferable, and in the case of mydriasis imaging, the external fixation target is more convenient because the internal fixation lamp is canceled out by the illumination light and becomes invisible.

[0010] However, the fundus camera described in Japanese Patent Application Laid-Open No. 8-66372 is configured to use an external fixation lamp in both mydriatic and non-mydriatic photography. Therefore, in this fundus camera, in order to reduce the possibility of miosis caused by near vision, the light amount of the fixation lamp is reduced during non-mydriatic photography, but the fixation lamp is in front of the eye to be examined. The likelihood of miosis has not been sufficiently reduced.

The present invention has been made in view of these problems, and is a fundus camera that can be used for both mydriatic and non-mydriatic photography. In addition, the fundus image can be observed on the same television monitor, and the fundus image can be observed with visible light during mydriatic photography, and an internal fixation target is used for non-mydriatic photography. Accordingly, it is an object of the present invention to provide a fundus camera that can eliminate the possibility of miosis of the subject's eye due to near vision.

[0012]

In order to achieve the above object, a fundus camera according to claim 1 comprises: an illumination light guiding optical system for guiding illumination light for illuminating an eye to be inspected to a fundus of the eye to be inspected;
An illumination switching means for switching illumination light of the illumination light guiding optical system between visible light and infrared light, a photographing light guiding optical system for guiding photographing light for photographing the eye to be examined to the fundus of the eye, and A photographing optical system for photographing the fundus of the eye to be inspected illuminated by light, which is inserted into an optical path of the photographing optical system, has a property of reflecting both visible light and infrared light, and from the optical path during photographing; A reflecting mirror that is instantaneously detached and inserted into the optical path immediately after shooting is completed, a television camera having sensitivity to visible light and infrared light, and a light beam reflected by the reflecting mirror is guided to the television camera. An observation optical system for observing a fundus image of a subject's eye, wherein the fundus camera has an infrared light transmission that is removably disposed in an optical path of the observation optical system, reflects visible light, and transmits infrared light. Guiding mirror and eye gaze An internal fixation target projection optical system for projecting an internal fixation target for the subject's eye via the infrared light transmitting mirror for illumination, and the illumination switching means includes an infrared light transmitting mirror for transmitting light to an optical path. The illumination light source is switched to infrared light in conjunction with insertion, and the illumination light is switched to visible light in conjunction with the departure of the infrared transmission mirror from the optical path.

According to the fundus camera of the first aspect, the fundus image is transmitted through the photographing light guiding optical system, the reflecting mirror, and the observation optical system regardless of whether the illumination light is visible light or infrared light. Image. Therefore, in both cases of mydriasis photography and non-mydriasis photography, an observation image can be captured by the same television camera. In addition, since a television camera having sensitivity to both infrared light and visible light is used, a fundus image due to visible light can be observed during mydriatic photography,
At the time of non-mydriatic photography, the fundus image can be observed with infrared light.

Further, according to this fundus camera, an infrared light transmitting mirror that reflects visible light and transmits infrared light is disposed so as to be freely inserted into and removed from the optical path of the observation optical system. The fixation target is projected by the internal fixation target projection optical system via the camera, and the illumination switching unit is switched in conjunction with the insertion / removal of the infrared light transmitting mirror.

When the infrared light transmitting mirror is inserted, the illumination system is switched to infrared light by the illumination switching means, and the illumination system is illuminated. Non-mydriatic imaging can be performed by using an internal fixation target. It is not necessary to use an external fixation target at the time of non-mydriatic imaging, and it is possible to eliminate miosis of the subject's eye based on near vision. Further, when the infrared light transmitting mirror is detached from the optical path, the light is switched to visible light by the illumination switching means and is irradiated to perform mydriatic photographing with visible light, and the infrared light transmitting mirror is detached. Therefore, the infrared light transmitting mirror does not obstruct the observation of the fundus.

[0016]

Embodiment 1 Hereinafter, Embodiment 1 of the present invention will be described.
A fundus camera capable of performing both general color imaging and visible fluorescence imaging will be described with reference to the drawings.

In FIG. 1, reference numeral 50 denotes an illumination light guiding optical system for guiding illumination light for illuminating the eye E to be examined to the fundus of the eye to be examined, and an imaging light guide for guiding photographing light for photographing the eye E to the fundus of the eye to be examined. An illumination system as an optical optical system, and reference numeral 51 denotes an observation / photographing optical system. This observation / photographing optical system 51
Is composed of a shared optical system 52, an observation optical system (observation system) 53, and an imaging optical system (imaging system) 54.

The illumination system 50 includes a concave mirror 55, a halogen lamp (observation light source) 56, a condenser lens 57, an infrared transmission filter 58, an infrared cut filter 94, an annular xenon lamp (photographing light source) 59, a ring diaphragm 60, A relay lens 61, a black spot plate 62, a focusing index mechanism 63,
It has a relay lens 64. The ring aperture 60 is the eye E
Is substantially conjugate with the pupil of the objective lens 265,
Is substantially conjugate with the aperture stop 267 when is considered as a reflection surface.

An exciter filter insertion / removal mechanism 65 for inserting an exciter filter 66 into the illumination light path during fluorescent imaging between the ring stop 60 and the relay lens 61;
A light amount adjustment insertion / removal mechanism 65 'for adjusting the amount of illumination light is provided. The exciter insertion / removal mechanism 65 and the dummy filter 6
7 and a solenoid 68, and the exciter filter 66 and the dummy filter 67 are alternately inserted and removed in the optical path by operating an exciter switch 65SW (not shown). Further, the light amount adjusting / inserting / removing mechanism 65 ′ is N
It roughly comprises a D filter 66 ', a dummy filter 67' and a solenoid 68 '.

The infrared transmission filter 58 and the infrared cut filter 94 are arranged so as to be able to be inserted into and removed from the optical path of the illumination system 50. In this embodiment, the infrared transmission filter 5
8 can be moved by a solenoid 58S (not shown), and the infrared cut filter 94 can be moved by a solenoid 94S (not shown). These solenoids 58S and 94S are, as shown in FIG. It is connected to a control circuit (control system) 1000, and is linked to the insertion and removal of an infrared light transmitting mirror constituting a fixation target projection optical system G, which will be described later. Since these solenoids 68, 68 ', 58S, and 94S are means for inserting and removing each optical member, they are not limited to solenoids.
A stepping motor or the like may be used.

The infrared transmission filter 58 removes visible light that causes miosis from the observation light source so that non-mydriatic pupils can be observed. For example, as shown in FIG.
An optical member that transmits only infrared light having a wavelength of about 830 nm or more is used. The infrared cut filter 94 is for cutting unnecessary infrared light from the observation light source when performing observation with visible light.
An optical member that transmits only visible light of 0 nm or less is used. The exciter filter 66 is inserted into the illumination system in order to provide necessary illumination during fluorescent imaging. For example, as shown by a solid line in FIG.
An optical member that transmits illumination light as infrared imaging light and infrared light having a wavelength of 820 nm or more is used.

The focusing index mechanism 63 is inserted as necessary, and for example, roughly comprises a lamp 164, a condenser lens 165, an infrared transmission filter 166, an index 167, a relay lens 168, and a glass plate 169, as shown in FIG. ing. The glass plate 169 has a dichroic mirror section 169a, and the dichroic mirror section 169 transmits visible light and reflects infrared light. The details of the focusing index mechanism 63 are described in, for example,
The focusing mechanism 63 is moved in the optical axis direction in conjunction with a focusing lens described later.

The common optical system 52 includes an objective lens 265, a perforated mirror 266, an aperture stop 267, and a half mirror 26.
8, a focusing lens 69, an imaging lens 70, and a quick return mirror 71. The quick return mirror 71 has a property of reflecting both visible light and infrared light, and is instantaneously separated from the optical path during photographing and inserted into the optical path immediately after photographing is completed.

An insertion / removal mechanism 86 for inserting / removing the barrier filter 93 is provided between the half mirror 268 and the focusing lens 69. The insertion / removal mechanism 86 includes a dummy filter 92.
And a barrier filter 93. As shown in FIG. 5, the barrier filter 93 has a transmission characteristic of selectively transmitting light having a wavelength of 530 nm to 640 nm.

The common optical system 52 is provided with an alignment optical system 72. This alignment optical system 72
Has an alignment light source 73, a light guide 74, a mirror 75, a two-hole aperture 76, and a relay lens 77. The two-hole aperture 76 has a pair of holes 76a, 76a as shown in FIG.
Having. The alignment optical system 72 emits visible light or infrared light. Switching between visible light and infrared light is
This may be performed by inserting and removing an infrared transmission filter (not shown) in the optical path between the mirror 75 and the light guide 74, or separately from the alignment light source 73 that generates light having a wavelength in the visible light range. An alignment light source (not shown) for generating light having a wavelength in the external light range may be provided to switch between observation using infrared light and observation using visible light.

The light incident on the light guide 74 is emitted from the exit end, and the light emitted from the exit end is reflected by the mirror 75 as alignment light, and is reflected by the hole 76a,
The light is guided to the relay lens 77 through 76a, and the relay lens 77 once forms an image of the exit end of the light guide 74 at the center position X of the hole 266a of the perforated mirror 266.

The pair of alignment lights once formed at the center position X are guided to the cornea C of the eye E through the objective lens 265. Here, when the working distance W from the eye E to the apparatus main body and the position of the apparatus main body with respect to the eye E in the up, down, left, and right directions are appropriate, the pair of alignment light beams makes the half of the corneal curvature center half.
Is projected at the position of. When the working distance W from the subject's eye E to the apparatus main body is deviated from an appropriate position, the alignment image based on the pair of alignment light beams is separated and projected at a half position of the corneal curvature center of the cornea C. Is done. The alignment reflected light beam reflected by the cornea C is imaged by the objective lens 265 at the conjugate position R with the fundus Ef when the working distance W is appropriate. The alignment reflected light beam imaged at the position R passes through the hole 266a and is guided to the observation optical system 53 similarly to the light beam forming the fundus image.

The observation optical system 53 includes a field lens 78,
Reflecting mirror 79, relay lens 80, area CCD 81
, A processing circuit 83 having a built-in memory, and a television monitor 84. The television camera 82 has sensitivity in the visible region and the infrared region.

In the present invention, an infrared light constituted by a dichroic mirror or the like which transmits infrared light and reflects visible light is provided in the optical path between the field lens 78 and the reflection mirror 79 of the observation optical system 53. By providing the transmissive mirror 95 so that it can be inserted and removed, a fixation target projection optical system G that is used for non-mydriatic imaging and keeps the line of sight of the subject's eye constant can be inserted and removed.

The details of the fixation target projection optical system G are not limited as long as the infrared light transmitting mirror 95 is provided in the optical path of the observation optical system 53 so as to be freely inserted and removed. In the first embodiment,
As shown in FIG. 7, a relay lens 96 and a pair of right and left fixation light sources 97 and 98 such as light emitting diodes (LEDs) corresponding to the left and right eyes are provided on the reflection surface 95a side of the infrared light transmitting mirror 95. Are provided.

The infrared light transmitting mirror 95 is provided so as to be inserted into and removed from the optical path of the observation optical system 53, and is operated by operating a mirror switch 95SW (not shown) so that the optical path is not used in non-mydriatic photography. And is removed from the optical path during mydriasis photography. During mydriasis photography, a fixation lamp (external fixation target) attached to the tip of a flexible arm outside the apparatus is used, but its detailed drawing is omitted.

The luminous flux emitted from the fixation light source 97 (or 98) passes through a pinhole 97 '(98') as an aperture, is condensed by a relay lens (fixation projection lens) 96, and is focused on infrared light. It goes to the transmission mirror 95. When the infrared light transmitting mirror 95 is inserted into the observation optical system 53,
The fixation target reflected by the infrared light transmitting mirror 95 is reflected by the quick return mirror 71 via 78,
An image is formed on the optical axis once on the fundus conjugate plane R through each optical system element of the common optical system 52 and is projected on the fundus oculi Ef of the eye E to be examined.

The photographing optical system 54 includes a prism 85 with a field lens, a relay lens 87, a television camera 89 having an area CCD 88, and a processing circuit 9 having a built-in memory.
0, consisting of a TV monitor 91. The television camera 89 is mounted on a first mount of a fundus camera body (not shown).

As shown in FIG. 9, the control circuit 1000
Mirror switch 95SW, exciter switch 66S
W, the solenoid 58S, the solenoid 94S, the exciter insertion / removal mechanism 65, and the insertion / removal mechanism 86, and their operations will be described later. The control circuit 1000 receives other input signals from switches corresponding to various photographing modes and observation / photographing means, and other control mechanisms (including other insertion / removal mechanisms) in conjunction with the input signals. However, since these details are known, they are omitted.

Next, the operation of the fundus camera constructed as described above will be described in terms of the non-mydriatic pupil in color photography and visible fluorescence photography.
The description will be made separately for the mydriatic imaging mode, but the present invention is not limited to this.

(A) General color photography by non-mydriatic photography (color / mydriatic photography mode) When performing non-mydriatic photography, the examiner first operates the mirror switch 95SW to operate the infrared light transmitting mirror. 95 is inserted into the optical path. Then, the fundus oculi Ef is generated by the fixation target projection optical system G.
The fixation target is projected on the eye, and the eye gaze of the eye E is fixed.
At this time, the fixation target projection optical system G serves as an internal fixation target.

When the infrared light transmitting mirror 95 is inserted, based on the input signal of the mirror switch 95SW,
The control circuit 1000 is operated, the solenoid 58S is driven, the infrared transmission filter 58 is inserted into the optical path of the illumination system 50, the solenoid 94S is driven, and the infrared cut filter 94 is retracted from the optical path of the illumination system 50. At this time,
The dummy filter 67 'is inserted in the optical path.
Since this photographing is not a fluorescent photographing, the dummy filter 9 is used.
2 and a dummy filter 67 are inserted in the optical path.

An alignment index is projected toward the eye E by the alignment optical system 72 switched to infrared light. Here, when the halogen lamp 56 is turned on,
The visible light is cut by the infrared transmission filter 58, and only the infrared light passes through the infrared transmission filter 58, and the objective lens 2
Infrared light is emitted to the fundus oculi Ef via 65. Since the illumination light applied to the eye to be examined is infrared light, there is almost no miosis of the eye to be examined, and thus there is no need to apply eye drops with a mydriatic agent.

The reflected light (infrared light) from the fundus Ef is reflected by the quick return mirror 71 via the shared optical system 52 and guided to the observation optical system 53. This observation optical system 5
An infrared light transmitting mirror 95 for branching the fixation target projection optical system G is inserted in the optical path of No. 3, but since the observation light is infrared light, this fundus image is transmitted by infrared light. Mirror 95
And is reflected by the reflection mirror 79 to be formed on the television camera 82. The formed fundus image is output as a video signal by the area sensor 81 to the television monitor 84 via the processing circuit 83. Thus, a fundus image as a visible image is displayed on the screen 84a on the television monitor 84.

The examiner adjusts the alignment based on the fundus image and the alignment index image. FIG. 8A,
As shown in FIG. 8B, an alignment image AI is received by the television camera 82. When the working distance W from the subject's eye E to the apparatus main body is at an appropriate position, the alignment image AI is as shown in FIG. When the working distance W from the subject's eye E to the apparatus main body is not at the proper position, it is displayed separately as shown in FIG. 8B, and the examiner can separate and non-separate the alignment image AI. , The apparatus main body can be aligned with the eye E.

Further, an index image 67 '' based on the focus index mechanism 63 is displayed on the screen 84a. Since the transmission of infrared light is cut in the reflection area of the dichroic mirror section 169a, the area 169a ′ other than the area where the index image 67 ″ is formed becomes a dark area, and the index image 67 ″ is formed.
Will appear to be raised, so this index image 6
You can adjust the focus while watching 7 ''.

After the alignment adjustment and the focusing are completed,
When a photographing switch (not shown) is pressed, an ND filter 66 'is inserted into the optical path of the illumination system 50 instead of the dummy filter 67' in synchronization with the operation of the photographing switch, and the xenon tube 59 emits light. In addition, the quick return mirror 71 of the common optical system 52 jumps up in synchronization with the operation of the photographing switch, the reflected light from the fundus Ef is guided to the photographing optical system 54, and the fundus image is formed on the television camera 89. The fundus image formed on the television camera 89 is displayed on the television monitor 91 and recorded. Thereby, color photography can be performed.

(B) General color photography by mydriasis photography (color / mydriasis photography mode) When performing mydriasis photography, the examiner first operates the mirror switch 95SW to move the infrared light transmitting mirror 95 through the optical path. Let go. In this state, since the internal fixation target by the fixation target projection optical system G is not used, the external fixation lamp (not shown) is turned on, and the line of sight of the subject's eye E is fixed by the external fixation target. This external fixation lamp is turned on by the mirror switch 95.
It may be linked with the operation of the SW.

In a state where the infrared light transmitting mirror 95 is detached, based on the input signal of the mirror switch 95SW,
The control circuit 1000 is operated, and 58S and 94S are driven. Thereby, the infrared transmission filter 58 is connected to the illumination system 50.
, And the infrared cut filter 94 is inserted into the optical path of the illumination system 50. At this time, the dummy filter 6
Reference numeral 7 'is inserted in the optical path of the illumination system 50, and since this imaging is not fluorescence imaging, the dummy filters 92 and 67 are inserted in the optical path. As a result, it becomes possible to observe and photograph the color fundus image by the mydriatic photographing method.

The alignment index is projected toward the eye E by the alignment optical system 72 switched to visible light. Here, when the halogen lamp 56 is turned on,
The infrared light is cut by the infrared cut filter 94, only the visible light passes through the infrared cut filter 94, and the visible light is emitted to the fundus oculi Ef via the objective lens 265. Since the illumination light applied to the eye to be examined is visible light, it is necessary to instill a mydriatic agent in order to avoid miosis of the eye to be examined.

The reflected light from the fundus oculi Ef passes through the common optical system 52,
It is guided to the television camera 82 via the observation optical system 53 in the same manner as in non-mydriatic photography. At this time, the infrared light transmitting mirror 9
5 is separated from the observation optical system 53, there is no obstacle in the optical path due to visible light, and the television camera 82 is sensitive to visible light, so that observation with visible light is possible.
Therefore, the examiner can observe the fundus oculi Ef of the eye E and the alignment index on the television monitor 84. In this case, focusing using the focusing index optical system 63 cannot be performed. The examiner adjusts the alignment based on the fundus and the alignment index.

After the alignment adjustment and the focusing are completed,
When the photographing switch is pressed, the ND filter 66 'is inserted into the optical path of the illumination system 50 instead of the dummy filter 67' in synchronization with the operation of the photographing switch, and the xenon tube 5
9 is emitted. In addition, the quick return mirror 71 of the common optical system 52 jumps up in synchronization with the operation of the photographing switch, the reflected light from the fundus Ef is guided to the photographing optical system 54, and the fundus image is formed on the television camera 89. The fundus image formed on the television camera 89 is displayed on the television monitor 91 and recorded. Accordingly, observation and color imaging of the eye E in the mydriatic state with visible light can be performed.

In this embodiment, the television camera 89
, The fundus image can be photographed by a 35 mm film camera or the like attached to a second mount (not shown).

(C) Visible Fluorescence Imaging by Infrared Observation (Infrared Observation / Fluorescence Imaging Mode) Next, the operation when performing visible fluorescence imaging using infrared light as observation light will be described. In this case, since infrared light is used as observation light, it is not necessary to apply a mydriatic to the eye to be examined. Before imaging, a fluorescent agent is injected into the subject, and imaging is performed using a fluorescent fundus image. At the observation stage, only a black and white fundus image can be seen.

When performing this photographing, the examiner first operates the mirror switch 95SW to insert the infrared light transmitting mirror 95 into the optical path of the observation optical system 53. Then, the fixation target is projected onto the fundus oculi Ef by the fixation target projection optical system G, and the line of sight of the eye E to be examined is fixed. At this time, the fixation target projection optical system G serves as an internal fixation target.

The control circuit 1000 controls the solenoids 58S, 94 based on the input signal of the mirror switch 95SW.
S to send a control signal to the
0 and the infrared cut filter 9
4 is retracted from the optical path of the illumination system 50.

In addition, the examiner uses an exciter switch 66SW.
Is operated, the exciter filter 66 is inserted into the optical path of the illumination system 50, and the dummy filter 67 is separated from the optical path.

As described above, the mirror switch 95S
When the infrared transmission filter 58 is inserted based on the operation of W and the exciter filter 66 is inserted based on the operation of the exciter switch 66SW, the control circuit 100
If 0, it is determined that the selected photographing mode is the infrared observation / fluorescence photographing mode, and the following control is performed.

A signal is sent to the light quantity adjusting insertion / removal mechanism 65 ′, and the dummy filter 67 ′ is inserted into the optical path of the illumination system.
The ND filter 66 'is retracted.

A control signal is sent to the insertion / removal mechanism 86 to separate the barrier filter 93 from the optical path of the common optical system 52,
The dummy filter 92 is inserted.

The alignment light beam of the alignment optical system 72 is switched to infrared light.

After the above settings are completed, a visible fluorescent agent is injected into the vein of the subject, and after the fluorescent agent has flowed into the fundus, the halogen lamp 56 is turned on to start observation.

An alignment index of infrared light is projected toward the eye E by the alignment optical system 72. Since the visible light component of the light from the halogen lamp 56 is cut by the infrared transmission filter 58, only the infrared light is guided to the exciter filter 66. As described above, since the exciter filter 66 has the characteristic of transmitting infrared light, the illumination light passes through the exciter filter 66 as it is and reaches the fundus.

The fundus reflection light of the illumination light is transmitted to the common optical system 5.
The light is guided to the quick return mirror 71 via the second mirror 2. Next, the light is reflected by the quick return mirror 71 and guided to the television camera 82 via the observation optical system 53, so that a black and white fundus image can be observed on the television monitor 84. The examiner displays the fluorescent image and the alignment index image on the television monitor 8.
Observe in 4 and adjust the alignment in the same way as general photography,
Focus is performed.

When the photographing switch is pressed after these operations are completed, the barrier filter 93 is synchronized with the operation of the photographing switch.
Is inserted into the optical path of the common optical system 52, and the quick return mirror 71 jumps up. Further, the xenon lamp 59 emits light in synchronization with this. The illumination light beam passes through the exciter filter 66 to become excitation light, and the perforated mirror 26
6. The excitation light and the visible fluorescence that reach the fundus via the objective lens 265 and are reflected by the fundus are guided to the barrier filter 93 of the shared optical system 52, and only the visible fluorescence passes through the barrier filter 93. The visible fluorescent light that has passed through the barrier filter 93 is guided to a television camera 89 of the imaging optical system 54, and a visible fluorescent image is formed on the television camera 89. This visible fluorescent image is reviewed and recorded on the television monitor 91.

(D) Visible fluorescence imaging by visible observation (visible observation / fluorescence imaging mode) When performing visible fluorescence imaging using visible light as observation light, the examiner first operates the mirror switch 95SW, The infrared light transmitting mirror 95 is separated from the optical path, and the fixation target projection optical system G is separated from the observation optical system 53. An external fixation lamp (not shown) is turned on to fix the line of sight of the subject's eye E with the external fixation target.

The control circuit 1000 controls the solenoids 58S, 94 based on the input signal of the mirror switch 95SW.
Send a control signal to S. Thereby, the infrared transmission filter 5
8 is retracted from the optical path of the illumination system 50, and the infrared cut filter 94 is inserted into the optical path of the illumination system.

In addition, the examiner sets the exciter switch 66SW
Is operated, the exciter filter 66 is inserted into the optical path of the illumination system 50, and the dummy filter 67 is separated from the optical path.

As described above, the mirror switch 95S
When the infrared cut filter is inserted based on the operation of W and the exciter filter 66 is inserted based on the operation of the exciter switch 66SW, the control circuit 100
0 determines that the selected imaging mode is the visible observation / fluorescence imaging mode, and performs the following control.

A signal is sent to the light amount adjusting / removing mechanism 65 ′ to insert the dummy filter 67 ′ into the optical path of the illumination system,
The ND filter 66 'is retracted.

A control signal is sent to the insertion / removal mechanism 86 so that the barrier filter 93 is inserted into the optical path of the common optical system 52 and the dummy filter 92 is retracted.

The alignment light beam of the alignment optical system 72 is switched to visible light.

After the above setting is completed, a visible fluorescent agent is injected into the vein of the subject, and the halogen lamp 56 is turned on after waiting for the fluorescent agent to flow into the fundus, and observation is started.

The alignment index of visible light is projected toward the eye E by the alignment optical system 72. Since the infrared light component of the light from the halogen lamp 56 is cut by the infrared cut filter 94, only the visible light is guided to the exciter filter 66. The exciter filter 66 has a wavelength of 450 nm or more in the transmitted visible light.
The light of 520 nm is selectively transmitted. This selectively transmitted light is
The light is guided to the fundus as fundus excitation light.

In the barrier filter 93, only the fluorescence from the fluorescent agent is transmitted, and the corneal reflection light of the fundus excitation light is cut. After passing through the barrier filter 93, the fluorescent light is reflected by the quick return mirror 71, guided to the television camera 82 via the observation optical system 53, and the fundus fluorescent image can be observed on the television monitor 84. The examiner observes the fluorescence image and the alignment index image on the television monitor 84, and performs alignment adjustment and focusing.

After these operations are completed, when the photographing switch is pressed, the xenon lamp 59 is synchronized with the operation of the photographing switch.
Emits light. At that time, the exciter filter 66 remains inserted in the optical path of the illumination system 50, and the barrier filter 93 remains inserted in the optical path of the shared optical system 52. Exciter filter 66
The excitation light that has passed through the aperture mirror 266 and the objective lens 2
It reaches the fundus via 65 and excites the fluorescent agent. Excitation light and visible fluorescence reflected by the fundus are shared optical system 52
And only visible fluorescence passes through the barrier filter 93. The visible fluorescence that has passed through the barrier filter 93 is guided to the television camera 89 of the photographing optical system 54 because the quick return mirror 71 is flipped up, and a visible fluorescence image is formed on the television camera 89. This visible fluorescent image is reviewed and recorded on the television monitor 91.

The conditions for inserting and removing each filter and each mirror are summarized and shown in Table 1 below.

[0073]

[Table 1]

In the first embodiment, the insertion / removal mechanism 86 is provided between the half mirror 268 and the focusing lens 69. However, the configuration is provided between the relay lens 87 of the photographing optical system 54 and the prism 85. In this case, the barrier filter 93 can be kept inserted in the optical path of the photographing optical system 54 in any photographing mode during observation. The barrier filter in this case functions as a barrier filter. (Modification 1) In the first embodiment, even when the infrared observation / visible fluorescence imaging mode is set, the infrared light transmission mirror 95 is attached and detached so that the visible observation / visible fluorescence The mode can be changed to the shooting mode.

As a result, not only the review image after photographing but also the fluorescent image from the observation stage can be obtained by the visible light only at the time when the fluorescent light starts to be emitted (specifically, until about 20 seconds after the injection of the fluorescent agent). You can see. Then, after the fluorescent agent has recirculated from the artery to the vein, the infrared light transmitting mirror 95 is inserted again into the optical path, and the infrared observation / visible fluorescence imaging mode is set again. As a result, the burden on the subject can be reduced as much as possible. (Modification 2) When the infrared observation / visible fluorescence imaging mode is set, for example, it may be set as follows. When the infrared transmission mirror 95 is detached, the infrared transmission filter 58 is retracted, the infrared cut filter 94 is inserted in the optical path, and the observation is changed to enable visible observation at any time. When inserted, the infrared transmission filter 58 is inserted, and the infrared cut filter 94 is detached from the optical path, so that infrared observation can be changed at any time.

Thus, the observation is performed with visible light only at the time when the fluorescence starts to be emitted, and after the photographing is started, the mode is changed to the infrared observation / fluorescence photographing mode. From the observation stage, a fluorescent image can be seen, and after the fluorescent agent has circulated from the artery to the vein, the infrared light transmitting mirror 95 is inserted again into the optical path,
Reset the mode to infrared observation / visible fluorescence imaging. As a result, the burden on the subject can be reduced as much as possible.

When the visual observation is temporarily performed in this photographing mode, the line of sight of the eye E may be guided by turning on the external fixation lamp. In this case, even if the light amount of the external fixation lamp is reduced and adjusted, the light amount of the observation light source is adjusted, or the light amount illuminated toward the eye E is adjusted by inserting an ND filter or the like. Good.

[0078]

Second Embodiment FIG. 10 shows a second embodiment of the present invention.
The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the second embodiment, the position of the insertion / removal mechanism 86 of the first embodiment is set between the prism 85 with the field lens of the photographing optical system 54 and the relay lens 87.
6 and the reflection mirror 7 of the observation optical system 53.
An observation barrier filter 99 that transmits both fluorescent light and infrared light is disposed between the mirror 9 and the infrared light transmitting mirror 95.

The barrier filter for observation 99 is, for example, a commercially available absorption filter (for example, HO) having a characteristic of transmitting light having a wavelength of 500 nm or more as shown in FIG.
YA Y-52) is used. As shown in FIG. 11, the excitation light source passing through the exciter filter 66 is almost cut off, but the observation barrier filter 99 has such a property that the excitation light is irradiated on the fundus oculi Ef and the fluorescence generated thereby can be transmitted. On the other hand, the barrier filter 93 is arranged in the photographing optical system and is dedicated to photographing.

The conditions for inserting and removing each filter and each mirror for each shooting mode are the same as those in the first embodiment.

For observation with visible light, the observation barrier filter 99 may be detached and a dummy filter having the same optical path length may be inserted instead.

According to the fundus camera having the above configuration, when the visible observation / visible fluorescence photographing mode is set in the first embodiment, the observation barrier filter 99 for selectively transmitting the fluorescence to the observation optical system 53 is provided. Since it is possible to adopt a configuration in which it is inserted, it is possible to correct the movement of the eye to be examined and the focus shift without missing the time when the fluorescence starts to be emitted. This makes it possible to facilitate fluorescence imaging and reduce the burden on the subject.

Generally, a band-pass filter in which a multilayer film is deposited is used as a fluorescent filter (exciter filter 66, barrier filter 93, etc.). Then, in order to efficiently separate the light having a wavelength of 520 nm from the fluorescence, the rising from the transmission to the non-transmission needs to be steep. on the other hand,
As in Embodiment 2, since there is usually a gap between the wavelength of the excitation light source and the fluorescence wavelength, there is no need for the rising as the observation barrier filter to be steep.
An inexpensive commercially available absorption filter can be processed into an appropriate thickness and used.

The other configuration and operation are the same as those of the first embodiment, and thus detailed description is omitted.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. Included in this invention.

For example, in the above embodiment, the description has been given based on the fundus camera capable of performing both the general color photographing and the visible fluorescent photographing. However, in these embodiments, the color photographing and the visible fluorescent photographing are performed separately and independently. It may be a configured fundus camera. Further, the present invention can also be applied to a fundus camera capable of performing infrared fluorescence imaging and other fundus cameras.

Although the infrared observation has been described on the premise that there is no mydriasis, imaging using a mydriatic agent may be performed.

[0089]

Since the fundus camera according to the present invention is constructed as described above, it is a fundus camera that can be used for both mydriatic and non-mydriatic photography. In the case of, the fundus image can be observed on the same TV monitor, the fundus image can be observed with visible light during mydriasis photography, and the internal fixation target can be observed during mydriasis photography. By using this, the possibility of miosis of the subject's eye due to near vision can be eliminated.

[Brief description of the drawings]

FIG. 1 is an optical diagram showing an entire configuration of a fundus camera according to a first embodiment of the present invention.

FIG. 2 is an optical diagram showing a configuration of a focusing indicator mechanism.

FIG. 3 is a transmission characteristic diagram of an infrared transmission filter 58;

FIG. 4 is a transmission characteristic diagram of the exciter filter 66.

FIG. 5 is a transmission characteristic diagram of the barrier filter 93.

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

FIG. 7 is an optical diagram of a fixed target projection optical system G;

8A and 8B show a fundus image at the time of observation displayed on the screen of the monitor device, FIG. 8A shows a state in which the apparatus main body is at an appropriate working distance with respect to the eye to be inspected, and FIG. This shows a state where the apparatus main body is not at the proper working distance.

FIG. 9 is a block diagram of a control circuit.

FIG. 10 is an optical diagram showing an entire configuration of a fundus camera according to a second embodiment of the present invention.

FIG. 11 is a transmission characteristic comparison diagram of the exciter filter 66, the barrier filter 93, and the observation barrier filter 99.

[Explanation of symbols]

 E Eye to be inspected Ef Fundus G Fixed index projection optical system 50 Illumination system 51 Observation / photographing optical system 52 Shared optical system 53 Observation optical system 54 Imaging optical system 66 Exciter filter 71 Quick return mirror (reflecting mirror) 86 Insertion / extraction mechanism 92 Dummy filter 93 Barrier filter 94 Infrared cut filter 95 Infrared light transmitting mirror 99 Barrier filter for observation 1000 Control circuit

Claims (1)

[Claims] An illumination light guiding optical system for illuminating an eye to be inspected with illumination light including visible light and infrared light and guiding the illumination light to the fundus of the eye to be inspected; Illumination switching means for switching between, a photographing light guiding optical system for guiding photographing light for photographing the eye to be examined to the fundus of the eye to be examined, and a photographing optical system for photographing the fundus of the eye to be examined illuminated by the photographing light, A reflecting mirror that is inserted into the optical path of the imaging optical system, has a property of reflecting both visible light and infrared light, and is instantaneously separated from the optical path during imaging and inserted into the optical path immediately after the end of imaging. A television camera having sensitivity to both visible light and infrared light; an observation optical system for observing a fundus image of a subject's eye by guiding a light beam reflected by the reflector to the television camera; It is placed in the optical path of the system An infrared light transmitting mirror that reflects visible light and transmits infrared light, and an internal fixation target for guiding the line of sight of the eye to be inspected is projected toward the eye through the infrared light transmitting mirror. An internal fixation target projection optical system, wherein the illumination switching means switches the illumination light to infrared light in conjunction with the insertion of the infrared light transmission mirror into an optical path, and the infrared light transmission mirror is The fundus camera, wherein the illumination light is switched to visible light in conjunction with departure from the optical path.