JPH0966032A - Fundus camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To observe a satisfactory eyeground image and to easily execute exact focusing by varying the brightness of a target for focusing corresponding to any selected image pickup means or observing means. SOLUTION: A light quantity control part 41 is connected to a light source 29 for moving image observation and a light quantity control part 42 is connected to a light source 37 for target projection so that the brightness of the target for focusing projected on the eyeground Er can be changed. Further, an optical path detecting means 38, video adapter detecting means 39, filter detecting means 40 and light quantity adjusting means 44 connect outputs to a judge processing part 43 and its output is connected to the light quantity control parts 41 and 42. In a color image pickup mode, the illuminating light flux reaching the eyeground Er and the light reflected from the eyeground Er by the focusing target light flux form the eyeground image and a focusing target image on focusing glass 9. This focusing target image is observed through an optical finder and while adjusting the quantity of light at the light source 29 for moving image observation with the light quantity adjusting means 44, the main body of the fundus camera and the eye E to be inspected are aligned or focused.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fundus camera having an index projection optical system for focusing and capable of macroscopic observation and observation / photographing by a plurality of image pickup means having different sensitivities.

[0002]

2. Description of the Related Art Conventionally, in a fundus camera, an operator looks into a finder and adjusts the diopter of an eyepiece lens to a mark on a focus glass provided at a position conjugate with the film surface, and the mark and the fundus image are both displayed. The focus is adjusted by moving the focus adjustment mechanism so that it can be seen clearly.

However, since the focus adjustment has individual differences depending on the skill of the operator, the applicant of the present invention disclosed in Japanese Patent Laid-Open No.
Japanese Patent Application Laid-Open No. 9-123618 proposes an apparatus that can easily perform focusing only by matching separated focus index images.

Further, in the case of fluorescence photography, the fluorescent blood vessel image is observed thin in the initial stage after the injection of the fluorescent agent, and the focus index image interferes with the same brightness of the focus index image as in color photography. There is a drawback that it is difficult to observe a fine blood vessel image.

For this reason, in Japanese Unexamined Patent Publication No. 63-260531, when observing the fluorescence image of the fundus of the eye to be examined,
A fundus camera has been proposed in which the brightness of a focus index image is reduced in association with the insertion / removal of a fluorescence photographing filter.

On the other hand, recently, in addition to visible light fluorescence imaging, ICG for observing and photographing the state of blood vessels of the retina and choroid by injecting a fluorescent agent ICG that emits infrared light fluorescence into a vein of a subject. Infrared fluorescence contrast methods have been performed.
This ICG infrared fluorescent image is observed and photographed using an electronic image pickup device such as a CCD camera. Since the fluorescence at this time is bright in the initial stage and dark in the latter stage, the sensitivity of the CCD camera is low in the initial stage and in the latter stage. The need to raise it arises.

Therefore, the initial stage of bright fluorescence is C
Since it is not necessary to increase the sensitivity of the CD camera, a CCD camera with high resolution is used for shooting, and CCD with an image intensifier is used in the latter stage when sensitivity is required.
The camera is being used.

[0008]

However, as in the above-mentioned conventional fundus camera, even in fluorescence photography using the same filter, the required light amount differs depending on the observation and photography medium. In the case of a configuration in which the brightness of the focus index image is reduced by linking with, for example, at the same brightness as the focus index image for fluorescence photography, a good fundus observation image and focus index during observation of still image shooting. Although an image can be obtained, the index image for focusing is too bright during observation of a moving image, which hinders focusing and fundus observation, and a good fundus observation image and index image for focusing are provided in all of these various shooting modes. The problem arises that it cannot be obtained.

An object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide a fundus camera capable of observing a good fundus image in all shooting modes such as various shooting methods and shooting media, and easily performing accurate focusing.

[0010]

A fundus camera according to the present invention for achieving the above object has index projection means for focusing and a plurality of photographing means can be selected or an observation means and a photographing means can be selected. In a possible fundus camera, the brightness of the focusing index is changed according to the selected photographing means or observation means.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 shows a configuration diagram of the first embodiment,
The objective lens 1 is arranged so as to face the eye E to be inspected, and on the optical axis O1 behind the objective lens 1, a perforated mirror 2, a photographing diaphragm 3, a focus lens 4, an imaging lens 5, and a switching mirror 6 are provided. , The film surface 7 is sequentially arranged. The switching mirror 8 is arranged in the reflection direction of the switching mirror 6,
A focusing glass 9 and an eyepiece lens 10 are arranged in the reflection direction of the switching mirror 8, and the focusing glass 9 and the eyepiece lens 1 are arranged.
0 constitutes an optical finder.

The television finder 11 including the first infrared fluorescent barrier filter 11a and the imaging lens 11b, and the observation CCD camera 12 can be attached to and detached from the optical finder as required. ing. The first infrared fluorescence barrier filter 11a includes a part of the fundus reflection light of the excitation illumination light whose wavelength is selected by the infrared fluorescence exciter filter described later, and the infrared fluorescence light flux excited by the ICG. It has a property of transmitting light.

On the other hand, behind the switching mirror 8, the film conjugate plane F, the field lens 14, the mirror 15, and the second
The infrared fluorescent barrier filter 16 and the TV relay lens 17 are sequentially arranged, and the field lens 14,
A television relay optical system is configured by the mirror 15, the second infrared fluorescent barrier filter 16, and the television relay lens. The second infrared fluorescent barrier filter 16
Is a characteristic that wavelength-separates the fundus reflected light of the excitation illumination light whose wavelength is selected by the exciter filter for infrared fluorescence described later and the infrared fluorescent light flux excited by the ICG, and transmits only the infrared fluorescent light flux. Have.

Behind the television relay lens 17, a high resolution CCD camera 18 for photographing an infrared fluorescent still image is provided.
And a high-sensitivity CCD camera 20 for infrared fluorescent video photography with an extender 19 attached selectively as necessary, and outputs from the high-resolution CCD camera 18 and the high-sensitivity CCD camera 20. Is connected in the order of a video recorder (not shown) and a TV monitor,
A photographing optical system is configured.

Furthermore, the optical axis O2 in the incident direction of the perforated mirror 2
Above, relay lenses 21 and 22, a ring slit 23 having a ring-shaped opening, an exciter filter 24 for infrared fluorescence, a mirror 25, a condenser lens 26, a light source 27 for taking a still image including a strobe tube, and a condenser lens 2.
8. Light sources 29 for moving images, which are composed of halogen lamps, are sequentially arranged to form an illumination optical system.

Exciter filter 24 for infrared fluorescence
The second infrared fluorescent barrier filter 16 can be inserted into and removed from the optical path, and can be replaced with a visible fluorescent exciter filter and a visible fluorescent barrier filter, respectively, depending on the purpose.

A rod mirror 30 which is removable from the illumination optical axis O2 is provided between the relay lenses 21 and 22 of the illumination optical system at a position optically conjugate with the fundus Er of the eye E to be examined. The lenses 31, 2 are arranged on the optical axis O3 in the reflection direction of the rod mirror 30.
A two-hole diaphragm plate 32 having two openings, a focus index plate 33 having a rectangular aperture focus index, a prism 34, a lens 35, a pinhole plate 36, and a light source 37 for index projection including a halogen lamp are sequentially arranged. And a focus index projection optical system is configured.

The focus index projection optical system includes a film surface 7, a film conjugate plane F, a focus index plate 33 and a fundus Er.
In order to always be optically conjugate with each other, they are moved along the optical axis O2 in the optical axis direction in conjunction with the focus lens 4 of the observation / photographing optical system.

Further, the switching mirror 8 is separated from the optical path to a position indicated by a dotted line in the figure, and the observation and photographing light flux is guided from the optical finder toward the film conjugate plane F, and the switching mirror 8 is inserted into the optical path. An optical path detecting means 38 such as a micro switch for detecting detachment is provided. Further, the optical finder is provided with a TV adapter detecting means 39 for detecting attachment / detachment of the TV adapter 11, and further a filter detecting means 40 for detecting insertion / removal of the infrared fluorescence exciter filter 24 into / from the illumination optical path. It is provided.

A light amount control unit 41 is connected to the moving image observation light source 29, and a light amount control unit 42 is connected to the index projection light source 37. The light amount control unit 42 turns on the light amount of the index projection light source 37. Can be switched to three levels, and thereby the brightness of the focus index projected on the fundus Er of the eye E can be changed. Further, the outputs of the optical path detecting means 38, the television adapter detecting means 39, the filter detecting means 40, and the moving light observation and photographing light quantity adjusting means 44 are connected to the judgment processing section 43, and the output of the judgment processing section 43 is the light quantity control section 41. , 42.

In the above structure, the filter detecting means 4
0 indicates that the infrared fluorescence exciter filter 24 is separated from the illumination optical system, and the optical path detecting means 38 is detected.
When it is detected that the optical path of the optical finder is selected, and when the TV adapter detection means 39 detects that the TV adapter 11 is not attached, the determination processing unit 43 selects the color photographing mode.

When the color photographing mode is selected, the illumination luminous flux emitted from the moving image observing light source 29 is condensed by the condenser lens 28, the still image photographing light source 27, and the condenser lens 2.
6, mirror 25, ring slit 23, relay lens 2
2, 21, the perforated mirror 2 and the objective lens 1 are used to reach the eye E to be inspected and illuminate the fundus Er.

On the other hand, the luminous flux emitted from the light source 37 for index projection is pinhole plate 36, lens 35, prism 34,
An image is once formed on the bar mirror 30 through the focus index plate 33, the aperture plate 32, and the lens 31, is reflected by the bar mirror 30, and follows the same path as the illumination light flux, and the fundus of the eye E to be inspected.
Reach Er. Note that the focus index light flux is the prisms 34, 2
If the eye fundus Er of the eye E to be inspected and the focus index are not conjugated, the eye diaphragm E is divided into two parts by the action of the aperture plate 32 or the like.
This focus index image appears to be separated into two. Therefore, the examiner can easily perform focusing by aligning the two focus index images separated into one.

The reflected light from the fundus Er due to the illumination light flux reaching the fundus Er and the focus index light flux passes through the objective lens 1, the photographing diaphragm 3, the focus lens 4, the image forming lens 5, and the switching mirrors 6 and 8 to focus glass. An image is formed on the image 9 and a fundus image and a focus index image are formed. The examiner observes the image on the focus glass 9 with an optical finder, and adjusts the light amount of the moving image observation light source 29 by using the moving image observation and photographing light amount adjusting means 44, while the fundus camera main body and the eye E to be inspected. Perform alignment and focus.

Since the color photographing mode has the largest amount of reflected light from the fundus Er at the time of observation as compared with the other photographing modes, the brightest focus index image is also required. Therefore, when the color photographing mode is selected, the determination processing unit 43 causes the light amount control unit 42 to turn on the index projection light source 37 with the highest light amount in the first stage, so that the examiner performs the color photographing. In mode, a good eye fundus image can be visually observed with the optical finder, so that focusing can be easily performed.

After the alignment and focusing are completed, the examiner presses a photographing switch (not shown) and the rod mirror 3
0 is separated from the optical axis O2, the switching mirror 6 is separated from the optical axis O1, the still image shooting light source 27 emits light, and the shooting illumination light flux emitted from the still image shooting light source 27 is a moving image observation light source. The optical path similar to that of the illumination light flux emitted from 29 reaches the eye E to be inspected and illuminates the fundus Er. Then, the reflected light from the fundus due to the photographing illumination light flux reaching the fundus Er is imaged and recorded on the film surface 7 via the objective lens 1, the photographing diaphragm 3, the focus lens 4, and the imaging lens 5.

Next, the filter detecting means 40 detects that the infrared fluorescent exciter filter 24 is inserted in the illumination optical system, and the optical path detecting means 38 detects that the optical path of the optical finder is selected. Further, the TV adapter 11 is detected by the TV adapter detecting means 39.
When it is detected that the
Selects the infrared fluorescence still image shooting mode.

When the infrared fluorescence still image photographing mode is selected, the illumination light flux from the moving image observing light source 29 is wavelength-selected by the infrared fluorescence exciter filter 24 and travels the same optical path as in the color photographing mode. , Reaches the eye E to be inspected through the objective lens 1 and illuminates the fundus Er. On the other hand, the light flux from the index projection light source 37 also reaches the fundus Er by following the same route as in the case of color imaging. Note that focusing is performed by aligning two separated focus index images, as in the case of color photography.

The illumination light flux whose wavelength has been selected is the eye E to be examined.
The ICG reaching the fundus Er of the mouse is excited to emit infrared fluorescence.
The fundus Er of the infrared fluorescent light flux and the wavelength-selected illumination light flux
The reflected light from the eye and the reflected light from the fundus Er of the focus index light flux include an objective lens 1, a photographing diaphragm 3, a focus lens 4,
An image is formed on the focus glass 9 via the imaging lens 5 and the switching mirrors 6 and 8 to form an infrared fluorescent fundus image and a focus index image. A television adapter 11 is attached to the optical viewfinder, and the image formed on the focus glass 9 is again observed CCD through the eyepiece lens 10, the first infrared fluorescent barrier filter 11a, and the image formation lens 11b. An image is formed on the imaging surface of the camera 12.

The examiner observes the infrared fluorescent fundus image and the focus index image projected on the television monitor (not shown) by the output of the observation CCD camera 12, and uses the light quantity adjusting means 44 to observe the moving light source 29. The fundus camera body and the subject's eye E are aligned and focused while adjusting the amount of light.

In the infrared fluorescent still image photographing mode, the amount of illumination reflected light from the fundus Er at the time of observation is smaller than that in the color photographing mode.
Does not require much light. Therefore, when the infrared fluorescence still image shooting mode is selected, the determination processing unit 43 causes the light amount control unit 42 to output the index projection light source 37 with the second stage of the larger light amount.
To turn on. As a result, the examiner can use the TV adapter 11 and the observation C in the infrared fluorescent still image shooting mode.
Since a good fundus image displayed on the television monitor can be observed using the CD camera 12, focusing can be easily performed.

After the alignment and focusing are completed, the examiner presses a photographing switch (not shown) and the rod mirror 3
0 is separated from the optical axis O2, the switching mirror 8 is separated from the optical axis O1 and the still image photographing light source 27 emits light, and the photographing illumination light flux is the same as the illumination light flux emitted from the moving image observation light source 29. Following the optical path, the eye E is reached and the fundus Er is illuminated.

The photographing illumination light flux whose wavelength is selected is the fundus of the eye.
The ICG that has reached Er is excited to emit infrared fluorescence. The reflected light of the infrared fluorescent light flux and the wavelength-selected illumination light flux from the fundus Er is passed through the objective lens 1, the photographing diaphragm 3, the focus lens 4, the imaging lens 5, and the switching mirror 6 and then onto the film conjugate plane F. An image is formed, and further, through the field lens 14, the mirror 15, the second infrared fluorescent barrier filter 16, and the television relay lens 17, the red image is picked up on the image sensor of the high-resolution CCD camera 18 for infrared fluorescent still image shooting. Only the external fluorescence image is formed and recorded in a still image memory (not shown).

Next, the filter detecting means 40 detects that the infrared fluorescent exciter filter 24 is inserted in the illumination optical system, and the optical path detecting means 38 selects the optical path of the television relay optical system. When detected, the determination processing unit 43 selects the infrared fluorescence moving image shooting mode.

When the infrared fluorescent moving image shooting mode is selected,
The switching mirror 8 is separated from the optical axis O1, the illumination light flux from the moving image observation light source 29 is wavelength-selected by the exciter filter 24 for infrared fluorescence, and travels along the same optical path as in the color photographing mode, and the objective lens 1 It reaches the eye E to be inspected through and illuminates the fundus Er. On the other hand, the light flux from the index projection light source 37 also reaches the fundus Er by following the same route as in the case of color imaging. Note that focusing is performed by aligning two separated focus index images, as in the case of color photography.

The wavelength-selected illumination luminous flux excites the ICG reaching the fundus Er to emit infrared fluorescence. The reflected light from the fundus Er of the infrared fluorescent light flux and the illumination light flux of which the wavelength is selected and the reflected light of the focus index light flux from the fundus Er are the objective lens 1, the photographing diaphragm 3, the focus lens 4, the imaging lens 5, An image is formed on the film conjugate plane F via the switching mirror 6, and further the field lens 14, the mirror 15, the second infrared fluorescent barrier filter 16, and the television relay lens 17 are formed.
High-sensitivity CCD camera 2 for infrared fluorescent video recording via
An image is formed on the image sensor of 0. The examiner observes the infrared fluorescent fundus image and the focus index image on the television monitor, and uses the light amount adjusting means 44 for moving image observation and photographing to use the light source 29 for moving image observation.
The fundus camera body and the subject's eye E are aligned and focused while adjusting the amount of light.

In the infrared fluorescent moving image shooting mode, the CCD camera 20 having high sensitivity is used because the amount of illumination reflected light from the fundus Er at the time of observation is smaller than that in the infrared fluorescent still image shooting mode. If the image has the same amount of light as in the infrared fluorescence still image shooting mode, halation is caused, which causes trouble in focusing. Therefore, when the infrared fluorescence moving image shooting mode is selected, the determination processing unit 43 causes the light amount control unit 42 to turn on the index projection light source 37 with the smallest light amount of the third stage.

As a result, the examiner, in the infrared fluorescence moving image shooting mode, can detect the high sensitivity CCD camera 20 for shooting the infrared fluorescence moving image.
Using, the good fundus image displayed on the television monitor can be observed, and focusing can be easily performed. When the alignment is completed, the examiner pushes a release switch (not shown) to remove the rod mirror 30 from the optical axis O2, and presses a recording switch of the video recorder to record an infrared fluorescent moving image.

FIG. 2 shows a block diagram of the second embodiment.
In addition to the configuration of the above embodiment, gain detecting means 45 for a high-sensitivity CCD camera is provided, and this gain detecting means 45 is the observation CCD camera 1 in the infrared fluorescence still image photographing mode.
2 is connected to the high-sensitivity CCD camera 20 in the infrared fluorescent moving image shooting mode, and the output of the gain detection means is connected to the determination processing unit 43. In this case, the light amount control unit 41 can continuously control the lighting amount of the index projection light source 37 to continuously change the brightness of the focus index projected on the fundus Er. Others are the same as those in FIG. 1 and the same reference numerals represent the same members.

In the infrared fluorescence still image photographing mode or the infrared fluorescence moving image photographing mode, I which has reached the fundus Er of the eye E to be examined.
Since the amount of infrared fluorescence emitted by CG changes depending on the elapsed time after intravenous injection, the examiner observes a television monitor (not shown) and adjusts the gain of the observation CCD camera 12 or the high-sensitivity CCD camera 20 to adjust the amount of light. The means 41 adjusts the amount of light of the moving image observing light source 29 to perform alignment and focusing.

The CCD camera gain detection means 45 detects the gain of the observation CCD camera 12 or the high-sensitivity CCD camera 20 and outputs the information to the judgment processing section 43. The judgment processing section 43 determines the photographing mode and the CCD. Camera 12 or 2
The light emission amount of the index projection light source 37 for focus index projection is determined from the gain of 0 and the light intensity of the moving image observation light source 29 via the light amount control unit 42.

Besides this, if the exciter filter 24 for infrared fluorescence and the barrier filters 11a and 16 for infrared fluorescence can be replaced by an exciter filter for visible fluorescence and a barrier filter for visible fluorescence, respectively, visible fluorescence photography can be performed. In the case of, alignment and focusing can be similarly performed. Further, instead of changing the amount of light emitted from the index projection light source 37 to change the brightness of the focusing index, the brightness of the focusing index is changed using an optical element such as an ND filter. May be.
It should be noted that the optical path detection unit 38 does not distinguish between the infrared fluorescent still image shooting mode and the infrared fluorescent moving image shooting mode, but
Both modes may be discriminated by detecting the mounted CCD camera 12 or 20.

[0043]

As described above, the fundus camera according to the present invention automatically sets the optimum brightness of the focusing index for each of various photographing methods and photographing modes such as a photographing medium. Therefore, a good fundus image can always be observed, and accurate focusing can be easily performed.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a configuration diagram of a second embodiment.

[Explanation of symbols]

 9 Focus Glass 11 TV Adapter 12 CCD Camera for Observation 18 High Resolution CCD Camera 20 High Sensitivity CCD Camera 27 Light Source for Still Image Shooting 29 Light Source for Video Shooting 33 Focus Indicator Plate 37 Light Source for Index Projecting 38 Optical Path Detector 39 TV Adapter Detector 40 Filter Detecting Means 41, 42 Light Amount Controlling Means 43 Judgment Processing Section 44 Video Intensity Adjusting Means 45

Claims (4)

[Claims] 1. An index projection means for focusing is provided,
In a fundus camera in which a plurality of photographing means can be selected or an observation means and a photographing means can be selected, the fundus characterized in that the brightness of the focusing index is variable according to the selected photographing means or observation means. camera. 2. The fundus camera according to claim 1, wherein the photographing means selects at least one of a plurality of electronic cameras and films having different sensitivities. 3. A filter detecting means for detecting whether or not a visible or infrared fluorescent filter is inserted in the optical path, and an optical path detecting means for detecting whether or not an optical path switching mirror is inserted in the observation and photographing optical path, or An electronic camera detection means for detecting an electronic camera selected from the plurality of electronic cameras, and an output from the filter detection means and an output from the optical path detection means or the electronic camera detection means. The fundus camera according to claim 2, wherein the photographing mode is selected based on the photographing mode. 4. An electronic camera gain detecting means for detecting a sensitivity setting of the selected electronic camera, for focusing based on the selected photographing mode and an output from the electronic camera gain detecting means. The fundus camera according to claim 3, wherein the brightness of the index is variable.