JP3696949B2 - Fundus camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fundus camera that has an index projection optical system for focusing and that can be observed and photographed with a plurality of imaging means having different visual sensitivities and sensitivity.
[0002]
[Prior art]
Conventionally, in the fundus camera, the operator looks through the viewfinder and adjusts the diopter of the eyepiece to the mark on the focus glass provided at a position conjugate with the film surface so that both the mark and the fundus image can be seen clearly. The focus adjustment mechanism is moved to adjust the focus.
[0003]
However, since this focus adjustment has individual differences depending on the skill level of the operator, the applicant can easily focus by simply matching the separated focus index images in Japanese Patent Laid-Open No. 49-123618. A device is proposed.
[0004]
Furthermore, in the case of fluorescent imaging, the fluorescent blood vessel image is thinly observed in the initial stage after the injection of the fluorescent agent, and the focus index image becomes a hindrance at the brightness of the same focusing index image as in color imaging. There is a drawback that it is difficult to observe the image.
[0005]
For this reason, in Japanese Patent Application Laid-Open No. 63-260531, when observing a fluorescence image of the fundus of the subject's eye, the fundus is designed to reduce the brightness of the focus index image in conjunction with the insertion / removal of the fluorescence imaging filter. A camera has been proposed.
[0006]
On the other hand, recently, in addition to fluorescent imaging of visible light, an ICG infrared fluorescence in which a fluorescent agent ICG that emits infrared fluorescent light is injected into a subject's vein to observe and photograph the state of blood vessels in the retina and choroid. An imaging method is performed. This ICG infrared fluorescent image is observed and photographed using an electronic image pickup device such as a CCD camera, and the fluorescence at this time is bright in the initial stage and dark in the late stage. Therefore, the sensitivity of the CCD camera is low in the initial stage and low in the late stage. There is a need to raise it.
[0007]
Therefore, since it is not necessary to increase the sensitivity of the CCD camera at the initial stage of emitting bright fluorescence, a CCD camera with high resolution is used for shooting, and the CCD camera with an image intensifier is used at the later stage requiring sensitivity. It is used.
[0008]
[Problems to be solved by the invention]
However, as in the above-described conventional fundus camera, the required light amount varies depending on the observation photographing medium even in the fluorescent photographing using the same filter. Therefore, the brightness of the focus index image is interlocked with the insertion and removal of the fluorescent photographing filter. In the case of a configuration that reduces the brightness, for example, at the same brightness as the focus index image for fluorescent photography, a good fundus observation image and a focus index image can be obtained at the time of still image photography observation. At the time of observation, the focus index image is too bright, which hinders focusing and fundus observation, and there is a problem that a good fundus observation image and focus index image cannot be obtained in all of these various photographing modes.
[0009]
An object of the present invention is to provide a fundus camera that solves the above-described problems, can observe a good fundus image in all shooting modes such as various shooting methods and shooting media, and can easily perform accurate focusing. There is.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a fundus camera according to the present invention includes a color photographing mode based on detection by a filter detection unit that detects insertion / removal of an infrared fluorescent exciter filter or a visible fluorescent exciter filter into / from an illumination optical path, and infrared fluorescent mode. An imaging mode selection means for selecting either an imaging mode or a visible fluorescence imaging mode, and an infrared fluorescence exciter filter in the infrared fluorescence imaging mode, and a visible fluorescence exciter filter in the visible fluorescence imaging mode . Illuminating means for illuminating the fundus, imaging means for allowing a change in gain and photographing a fundus image, index projecting means for projecting a focus index onto the fundus, the imaging mode selected by the imaging mode selection means, and the imaging and a determination processing unit for determining the brightness of the index for the focusing in accordance with the gain change in the unit And wherein the door.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail based on the embodiments shown in the drawings.
FIG. 1 shows a configuration diagram of the first embodiment, in which an objective lens 1 is arranged facing the eye E, and a perforated mirror 2 and an imaging aperture are placed on the optical axis O1 behind the objective lens 1. 3, the focus lens 4, the imaging lens 5, the switching mirror 6, and the film surface 7 are arranged in order. A switching mirror 8 is disposed in the reflection direction of the switching mirror 6, a focus glass 9 and an eyepiece lens 10 are disposed in the reflection direction of the switching mirror 8, and the focus glass 9 and the eyepiece lens 10 constitute an optical finder. Yes.
[0012]
The optical viewfinder is configured such that the television adapter 11 including the first infrared fluorescent barrier filter 11a and the imaging lens 11b and the observation CCD camera 12 can be attached and detached as necessary. The first infrared fluorescence barrier filter 11a includes a part of the fundus reflection light of the excitation illumination light wavelength-selected by the infrared fluorescence exciter filter, which will be described later, and the infrared fluorescence light flux excited by the ICG. It has a characteristic of transmitting through.
[0013]
On the other hand, behind the switching mirror 8, a film conjugate plane F, a field lens 14, a mirror 15, a second infrared fluorescent barrier filter 16, and a television relay lens 17 are sequentially arranged. 15, the second infrared fluorescent barrier filter 16 and the television relay lens constitute a television relay optical system. The second infrared fluorescence barrier filter 16 separates the fundus reflection light of the excitation illumination light wavelength-selected by the infrared fluorescence exciter filter described later and the infrared fluorescent light beam excited by the ICG. And has a characteristic of transmitting only the infrared fluorescent light flux.
[0014]
Further, behind the TV relay lens 17, a high-resolution CCD camera 18 for photographing infrared fluorescent still images and a high-sensitivity CCD camera 20 for photographing infrared fluorescent movies with an extender 19 are selected as necessary. Furthermore, the outputs of the high-resolution CCD camera 18 and the high-sensitivity CCD camera 20 are connected in the order of a video recorder and a television monitor (not shown) to constitute an observation / photographing optical system.
[0015]
Further, on the optical axis O2 in the incident direction of the perforated mirror 2, 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, and a strobe tube. A still image photographing light source 27, a condenser lens 28, and a moving image observation light source 29 including a halogen lamp are sequentially arranged to constitute an illumination optical system.
[0016]
The infrared fluorescent exciter filter 24 and the second infrared fluorescent barrier filter 16 are detachable 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. It has become.
[0017]
At a position optically conjugate with the fundus Er of the eye E between the relay lenses 21 and 22 of the illumination optical system, a bar mirror 30 that can be inserted and removed from the illumination optical axis O2 is provided. On the optical axis O3 in the reflection direction of the bar mirror 30, a lens 31, a two-hole aperture plate 32 having two openings, a focus index plate 33 having a rectangular aperture focus index, a prism 34, a lens 35, and a pinhole A plate 36 and an index projection light source 37 composed of a halogen lamp are sequentially arranged to constitute a focus index projection optical system.
[0018]
This focus index projection optical system is interlocked with the focus lens 4 of the observation / photographing optical system so that the film surface 7, the film conjugate plane F, the focus index plate 33 and the fundus Er are always optically conjugate. The optical axis O2 moves in the optical axis direction.
[0019]
Further, the switching mirror 8 is separated from the optical path to the position of the dotted line in the figure, and the observation photographing light beam is guided from the optical finder toward the film conjugate plane F, so that the switching mirror 8 is inserted into and removed from the optical path. Optical path detection means 38 such as a micro switch for detection is provided. Further, the optical viewfinder is provided with a television adapter detection means 39 for detecting the attachment / detachment of the television adapter 11, and further, a filter detection means 40 for detecting insertion / removal of the infrared fluorescent exciter filter 24 to / from the illumination optical path. Is provided.
[0020]
A light amount control unit 41 is connected to the moving image observation light source 29, a light amount control unit 42 is connected to the index projection light source 37, and the light amount control unit 42 determines the lighting amount of the indicator projection light source 37 in three stages. Thus, the brightness of the focus adjustment index projected onto the fundus Er of the eye E can be changed. Further, the outputs of the optical path detection means 38, the television adapter detection means 39, the filter detection means 40, and the moving image observation photographing light amount adjustment means 44 are connected to the determination processing section 43, and the output of the determination processing section 43 is the light amount control section 41. , 42.
[0021]
In the above configuration, the filter detecting means 40 detects that the infrared fluorescent exciter filter 24 is detached from the illumination optical system, and the optical path detecting means 38 detects that the optical path of the optical finder is selected. Further, when the television adapter detection means 39 detects that the television adapter 11 is not attached, the determination processing unit 43 selects the color photographing mode.
[0022]
When the color photographing mode is selected, the illumination light beam emitted from the moving image observation light source 29 is the condenser lens 28, the still image photographing light source 27, the condenser lens 26, the mirror 25, the ring slit 23, the relay lenses 22, 21, and the hole. It reaches the eye E through the perforated mirror 2 and the objective lens 1 to illuminate the fundus Er.
[0023]
On the other hand, the light flux emitted from the index projection light source 37 forms an image once on the rod mirror 30 via the pinhole plate 36, the lens 35, the prism 34, the focus index plate 33, the two-hole aperture plate 32, and the lens 31, The light is reflected by the bar mirror 30 and follows the same path as the illumination light beam to reach the fundus Er of the eye E to be examined. Note that the focus index light beam is separated into two by the action of the prism 34, the aperture plate 32, and the like. If the fundus Er of the eye E and the focus index are not conjugated, two focus index images are obtained. Looks separated. Accordingly, the examiner can easily focus by aligning the focus index images separated into two into one.
[0024]
Reflected light from the fundus Er due to the illumination light beam and the focus index light beam reaching the fundus Er is focused on the focus glass 9 via the objective lens 1, the photographing aperture 3, the focus lens 4, the imaging lens 5, and the switching mirrors 6 and 8. An image is formed to form a fundus image and a focus index image. 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 using the moving image observation photographing light amount adjusting means 44, while the fundus camera body and the eye E to be examined. Align and focus.
[0025]
Since the color imaging mode has the largest amount of reflected light from the fundus Er during observation compared to the other imaging modes, the focus index image needs to be the brightest. Accordingly, when the color photographing mode is selected, the judgment processing unit 43 causes the light quantity control unit 42 to turn on the index projection light source 37 with the highest light quantity in the first stage, so that the examiner can perform color photographing. Since a good fundus image can be observed with the optical viewfinder during the mode, focusing can be easily performed.
[0026]
After the alignment and focusing are completed, when the examiner presses a photographing switch (not shown), the bar mirror 30 is detached from the optical axis O2, and the switching mirror 6 is detached from the optical axis O1, and the still image photographing light source 27 is removed. The imaging illumination light beam emitted from the still image photographing light source 27 follows the same optical path as the illumination light beam emitted from the moving image observation light source 29 and reaches the eye E to illuminate the fundus Er. Then, the reflected light from the fundus of the photographing illumination light beam reaching the fundus Er is imaged and recorded on the film surface 7 through the objective lens 1, the photographing aperture 3, the focus lens 4 and the imaging lens 5.
[0027]
Next, the filter detection means 40 detects that the infrared fluorescence exciter filter 24 is inserted into the illumination optical system, and the optical path detection means 38 detects that the optical path of the optical finder is selected. When the television adapter detection unit 39 detects that the television adapter 11 is attached, the determination processing unit 43 selects the infrared fluorescent still image shooting mode.
[0028]
When the infrared fluorescent still image shooting mode is selected, the wavelength of the illumination light beam from the moving image observation light source 29 is selected by the infrared fluorescent exciter filter 24 and travels in the same optical path as in the color shooting mode. 1 to reach the eye E to illuminate the fundus Er. On the other hand, the luminous flux from the index projection light source 37 reaches the fundus Er by following the same path as in the case of color photography. Note that focusing is also performed by aligning two separated focus index images as in the case of color photography.
[0029]
This wavelength-selected illumination light beam excites the ICG reaching the fundus Er of the eye E to emit infrared fluorescence. The reflected light from the fundus Er of the infrared fluorescent light beam and the wavelength-selected illumination light beam and the reflected light from the fundus Er of the focus index light beam are the objective lens 1, the photographing aperture 3, the focus lens 4, the imaging lens 5, An image is formed on the focus glass 9 via the switching mirrors 6 and 8 to form an infrared fluorescent fundus image and a focus index image. A TV adapter 11 is attached to the optical viewfinder, and an image formed on the focus glass 9 is again observed through the eyepiece lens 10, the first infrared fluorescent barrier filter 11a, and the imaging lens 11b. An image is formed on the imaging surface of the camera 12.
[0030]
The examiner observes the infrared fluorescent fundus image and the focus index image projected on a television monitor (not shown) by the output of the observation CCD camera 12, and uses the light amount adjusting means 44 to change the light amount of the moving image observation light source 29. While adjusting, the fundus camera body and the eye E to be examined are aligned and focused.
[0031]
In the infrared fluorescent still image shooting mode, the amount of light reflected from the fundus Er during observation is smaller than that in the color shooting mode, so that the focus index image also requires less light than the color shooting mode. Therefore, when the infrared fluorescent still image shooting mode is selected, the determination processing unit 43 causes the light amount control unit 42 to light the indicator projection light source 37 with the second large amount of light. Thus, the examiner can observe a good fundus image displayed on the television monitor using the television adapter 11 and the observation CCD camera 12 in the infrared fluorescent still image photographing mode. It can be done easily.
[0032]
After the alignment and focusing are completed, when the examiner presses a photographing switch (not shown), the bar mirror 30 is detached from the optical axis O2, and the switching mirror 8 is detached from the optical axis O1, and the still image photographing light source 27 is removed. , And the photographic illumination light beam follows the same optical path as the illumination light beam emitted from the moving image observation light source 29, reaches the eye E to illuminate the fundus Er.
[0033]
This wavelength-selected photographing illumination light beam excites the ICG reaching the fundus Er and emits infrared fluorescence. The reflected light from the fundus Er of the infrared fluorescent light beam and the wavelength-selected illumination light beam is incident on the film conjugate plane F via the objective lens 1, the photographing aperture 3, the focus lens 4, the imaging lens 5, and the switching mirror 6. An image is formed and further red on the image sensor of the high-resolution CCD camera 18 for photographing an infrared fluorescent still image through the field lens 14, the mirror 15, the second infrared fluorescent barrier filter 16, and the television relay lens 17. Only the outer fluorescent image is formed and recorded in a still image memory (not shown).
[0034]
Next, the filter detection means 40 detects that the infrared fluorescence exciter filter 24 is inserted into the illumination optical system, and the optical path detection means 38 detects that the optical path of the television relay optical system is selected. Then, the determination processing unit 43 selects the infrared fluorescent moving image shooting mode.
[0035]
When the infrared fluorescent moving image photographing mode is selected, the switching mirror 8 is detached from the optical axis O1, and the wavelength of the illumination light beam from the moving image observation light source 29 is selected by the infrared fluorescent exciter filter 24, and the color photographing mode is selected. The same optical path as in the above case is followed, and the eye E is illuminated via the objective lens 1 to illuminate the fundus Er. On the other hand, the luminous flux from the index projection light source 37 reaches the fundus Er by following the same path as in the case of color photography. Note that focusing is also performed by aligning two separated focus index images as in the case of color photography.
[0036]
The wavelength-selected illumination light beam excites the ICG reaching the fundus Er and emits infrared fluorescence. The reflected light from the fundus Er of the infrared fluorescent light beam and the wavelength-selected illumination light beam and the reflected light from the fundus Er of the focus index light beam are the objective lens 1, the photographing aperture 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 for infrared fluorescent moving image shooting via the field lens 14, the mirror 15, the second infrared fluorescent barrier filter 16, and the television relay lens 17. An image is formed on the image sensor of the high sensitivity CCD camera 20. The examiner observes these infrared fluorescent fundus images and focus index images on a television monitor, and adjusts the light amount of the moving image observation light source 29 using the moving image observation photographing light amount adjusting means 44, while Align and focus with optometry E.
[0037]
In the infrared fluorescent movie shooting mode, the amount of reflected light from the fundus Er during observation is smaller than in the infrared fluorescent still image shooting mode, so the CCD camera 20 with high sensitivity is used, and the focus index image is red. If the amount of light is the same as in the outside fluorescent still image shooting mode, halation will occur and this will interfere with focusing. Therefore, when the infrared fluorescent moving image photographing mode is selected, the determination processing unit 43 so as to turn on the light quantity control unit 42 is index projection light source 37 with the least amount of the third stage.
[0038]
As a result, the examiner can observe a good fundus image displayed on the TV monitor using the high-sensitivity CCD camera 20 for infrared fluorescent moving image shooting in the infrared fluorescent moving image shooting mode. Matching can be performed easily. When the alignment is completed, the examiner presses a release switch (not shown) to release the bar mirror 30 from the optical axis O2, and presses the recording switch of the video recorder to record an infrared fluorescent moving image.
[0039]
FIG. 2 shows a configuration diagram of the second embodiment. In addition to the configuration of the first embodiment, gain detection means 45 for a high-sensitivity CCD camera is provided, and the gain detection means 45 is used to capture an infrared fluorescent still image. In the mode, it is connected to the observation CCD camera 12, and in the infrared fluorescent moving image shooting mode, it is connected to the high sensitivity CCD camera 20, and the output of the gain detection means is connected to the judgment processing unit 43. In this case, the light quantity control unit 42 can continuously change the brightness of the focusing index projected onto the fundus Er by continuously controlling the lighting quantity of the index projection light source 37. The other components are the same as those in FIG. 1, and the same reference numerals represent the same members.
[0040]
In the case of the infrared fluorescence still image shooting mode or the infrared fluorescence moving image shooting mode, the amount of infrared fluorescence emitted by the ICG reaching the fundus Er of the eye E changes depending on the elapsed time after intravenous injection. Observes a television monitor (not shown), adjusts the gain of the observation CCD camera 12 or the high-sensitivity CCD camera 20, and performs alignment and focusing while adjusting the light amount of the moving image observation light source 29 by the light amount control unit 41.
[0041]
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 determination processing unit 43. The determination processing unit 43 determines the shooting mode, the CCD camera 12 or The light emission quantity of the index projection light source 37 for focus index projection is determined from the gain of 20 and the light quantity of the moving image observation light source 29 via the light quantity control unit 42.
[0042]
Further, the infrared fluorescent exciter filter 24 and the infrared fluorescent barrier filter 11a, 16 a respectively configured to be capable of interchanging the exciter filter and visible fluorescence barrier filter for visible fluorescence, alignment in the same manner in the case of visible fluorescence photography And focus .
Also, instead of changing the brightness of 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. The optical path detection means 38 does not discriminate between the infrared fluorescent still image shooting mode and the infrared fluorescent moving image shooting mode, but discriminates both modes by detecting the mounted CCD camera 12 or 20. May be.
[0043]
【The invention's effect】
As described above, the fundus camera according to the present invention can automatically set the brightness of the optimum focus index for each shooting mode such as various shooting methods and shooting media. A good fundus image can always be observed and accurate focusing can be easily performed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a first embodiment.
FIG. 2 is a configuration diagram of a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 9 Focus glass 11 Television adapter 12 Observation CCD camera 18 High resolution CCD camera 20 High sensitivity CCD camera 27 Still image photographing light source 29 Moving image photographing light source 33 Focus index plate 37 Index projection light source 38 Optical path detection means 39 Television adapter detection means 40 Filter detection means 41, 42 Light quantity control section 43 Judgment processing section 44 Light quantity adjustment means for moving image observation photographing 45 CCD camera gain detection means

Claims (2)

An imaging mode for selecting one of a color imaging mode, an infrared fluorescence imaging mode, and a visible fluorescence imaging mode based on detection by a filter detection unit that detects insertion / removal of an infrared fluorescent exciter filter or a visible fluorescent exciter filter to / from an illumination optical path. selection means, via the infrared fluorescent exciter filter in the infrared fluorescent photographing mode, the above-illuminating means for illuminating the fundus of the eye through a visible fluorescent exciter filter in the visible fluorescence photographing mode, and allows to change the gain fundus determining a photographing means for photographing an image, a target projecting means for projecting an index for focusing the fundus, the brightness of the focusing for the index in accordance with a gain change in the photographing mode and the photographing means selected by the photographing mode selection means A fundus camera comprising: determination processing means for performing The fundus camera according to claim 1, wherein the index projection unit includes a light source, and the light source is controllable to a light emission amount determined by the determination processing unit .

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