JP3486466B2 - Fundus image storage device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fundus image storage device for electronically recording a fundus image of an eye to be inspected, which is used in an ophthalmology clinic or the like.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Application Laid-Open No. 5-199997 discloses a fundus camera capable of changing the size of a diaphragm to change the photographable range of the fundus of an eye to be examined.

Further, due to the recent advances in electronic image technology,
Since a medical image is recorded as a silver salt photograph, it is strongly expected to be recorded as an electronic image, and an image storage device that records a fundus image captured by a fundus camera as an electronic image has been put into practical use.

[0004]

However, in the fundus camera, when the recording range of the fundus of the eye to be examined is changed by changing the size of the diaphragm, the conventional image storage device has a constant storage capacity for one image. Therefore, when the recording range of the fundus image is narrowed to record it as an electronic image, a light-shielding area due to an extra aperture is also recorded, and the storage area is wasted.

The object of the present invention is to solve the above problems,
An object of the present invention is to provide a fundus image storage device capable of effectively utilizing the storage area according to the recording range of the fundus image.

[0006]

A fundus image storage apparatus according to the present invention for achieving the above object comprises an illumination optical system for illuminating the fundus of an eye to be examined, and a photographing optical system for photographing the illuminated fundus. A diaphragm provided at a position substantially conjugate with the fundus of the eye to be examined, a diaphragm for varying the size of the diaphragm, a diaphragm diameter changing means for changing the size of the diaphragm, and a fundus image storage means for electronically recording a fundus image. In a fundus image storage device having :, the image is stored in the image storage means in correspondence with the size of the diaphragm.
The feature is that the recording range of the image is changed.

[0007]

In the fundus image storage device having the above-mentioned structure, the recording range of the image to be recorded in the image storage means is changed according to the size of the variable diaphragm.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments. FIG. 1 is a configuration diagram of the first embodiment, in which an objective lens 1, a perforated mirror 2, a focusing lens 3, a fixed lens 4, and an optical path O1 in the line-of-sight direction of an eye E are moved along the optical path. Variable magnification lenses 5 and 6, a relay lens 7, a flip-up mirror 8 that can be retracted outside the optical path O1, a shutter 9, a photographic film 1
0s are sequentially arranged. Further, in the optical path O2 in the reflection direction of the flip-up mirror 8, a flip-down mirror 11, a field lens 12, and an optical path conversion mirror 1 which can retract from the optical path O2.
3, an imaging lens 14, and a television camera 15 are sequentially arranged, and an eyepiece lens 16 is arranged on the optical path O3 in the reflection direction of the flip-down mirror 11 so that a finder light beam is guided to the optometry e. The members from the objective lens 1 to the photographic film 10 and the members from the flip-up mirror 8 to the television camera 15 constitute a photographic optical system, and the members from the focusing lens 3 to the variable magnification lens 6 therein are variable. It constitutes a double imaging system.

The optical path O4 in the incident direction of the perforated mirror 2
The upper part is composed of a circular light shielding plate for shielding harmful reflected light of the cornea Ec, and is fixed to the corneal baffles 17 and 18, the relay lens 19 and the moving plate 20 which are selectively inserted in the optical path O4, and the opening diameter is fixed. Changing illumination field diaphragm 21, relay lens 22,
A crystalline lens baffle 2 consisting of a circular shading plate for preventing harmful reflected light of the crystalline lens Ep, which is selectively inserted in the optical path O4.
3, 24, ring slit 25, optical path changing mirror 26,
A first condenser lens 27, a photographing light source 28 including a strobe tube, a second condenser lens 29, an observation light source 30 including an incandescent lamp, and a condenser mirror 31 are sequentially arranged.

Here, the focusing lens 3 is connected to one end of a focus arm 33 fixed to the focus shaft 32 by a pin and a hole, and the movable plate 20 is similarly connected to the other end of the focus arm 33 by a pin and a hole. It is connected. The focus shaft 32 is connected to a focus knob (not shown), and the focusing lens 3 is moved in the optical path O1 direction by turning the focus knob.

Further, the perforated mirror 2 is an optical axis of the photographing optical system.
The corneal baffle 1 is arranged at the intersection of O1 and the optical axis O4 connecting the relay lenses 19 and 18, and with respect to this perforated mirror 2.
7 and 18 are conjugated with the anterior surface of the cornea Ec and the lens baffle 2
Ring slits 25, 3 and 24 are conjugated with the rear surface of the lens.
Are arranged conjugate with the pupil Ep. Further, the movable plate 20 is guided by a guide mechanism (not shown) so that it can move in the optical axis direction of the illumination optical system as shown by the arrow.

2 and 3 are partially enlarged views of the illumination field diaphragm 21, and FIG. 3 is a front view of the illumination field diaphragm 21. Long holes 41a, 41b for guiding and a hole 41c are formed in the slide plate 41, and guide screws 42, 4 are provided on the support of the diaphragm blade 21a.
3 is screwed together. The guide screw 42, 43 has a long hole 4
1a and 41b are loosely fitted so that the sliding plate 41 can move in a direction perpendicular to the optical axis.

An opening / closing pin 44 is fitted in the hole 41c of the sliding plate 41, and when the sliding plate 41 moves, the diaphragm blade 21a opens and closes. Further, a rack gear 45 is provided on the sliding plate 41, and the rack gear 45 is fitted with a pinion gear 47 that is axially supported by the shaft of a stepping motor 46. When the stepping motor 46 is rotationally driven, the pinion gear 47 is rotated accordingly and the rack 6 is rotated.
4 moves horizontally, and the sliding plate 41 further moves to open and close the diaphragm blade 21a.

A control circuit for controlling the entire apparatus is provided, and the CPU 51 has a RAM 52 for temporarily storing various data and a ROM for storing control procedures and the like.
53 and an I / O circuit 54 for controlling input / output signals to / from the CPU 51, respectively. The I / O circuit 54 has an input section 55 for inputting a photographing mode and the like from outside, and a motor for driving the stepping motor 46. The drive circuit 56, the image storage device 57, and the image memory changing device 58 are connected to each other. Further, an image memory changing device 58, a television monitor 59, and a television camera 15 are connected to the image storage device 57, respectively, and the image storage device 57 and the image memory changing device 58 are connected to the CPU 51 via the I / O circuit 54. It is designed to communicate data.

At the time of observation, the light flux emitted from the observation light source 30 is condensed in the vicinity of the photographing light source 28 by the condenser mirror 31 and the second condenser lens 29, and passes through the first condenser lens 27 to the optical path. The light is reflected by the conversion mirror 26 and is condensed on the ring slit 25 to illuminate it. The aperture of the illuminated ring slit 25 forms an annular secondary light source image, and the light flux from there passes through the lens baffle 23 or 24, the relay lens 22, the illumination field diaphragm 21, the relay lens 19, and the corneal baffle 17 or 18. , Is reflected by the perforated mirror 2 to the left, passes through the objective lens 1, and uniformly illuminates the fundus Ef of the eye E to be examined over a wide range. The reflected light from the fundus Ef returns through the same optical path, passes through the opening 2a of the perforated mirror 2, and is focused by the focusing lens 3, the fixed lens 4, the variable magnification lenses 5, 6, and the relay lens 7.
And is reflected by the flip-up mirror 8 and the flip-down mirror 11, respectively, and is observed as a fundus image by the optometry e through the eyepiece lens 16.

When the photographing light source 28 emits light during photographing, this luminous flux uniformly illuminates the fundus oculi Ef in the same manner as the illumination light from the observation light source 30. When recording the fundus image on the photographic film 10, the flip-up mirror 8 flips up to open the shutter 9 in synchronization with the light emission of the photographic light source 28, and the reflected light at the fundus Ef is taken as the fundus image as the photographic film 10. Image on top.
Further, when the fundus image is recorded in the image storage device 57, the flip-down mirror 11 jumps down in synchronization with the light emission of the photographing light source 28, and the reflected light on the fundus Ef is reflected by the flip-up mirror 8 and the field. The light passes through the lens 12, the optical path conversion mirror 13, and the imaging lens 14, and is formed as a fundus image on the television camera 15, converted into an image signal, input to the image storage device 57, and stored in an image memory prepared in advance. With
It is displayed on the television monitor 59.

Here, the illumination field stop 21 regulates the range illuminated by the illumination light on the fundus Ef to prevent harmful light from being mixed into the photographing light. Therefore, this illumination field diaphragm 2
The position 1 must be conjugate with the fundus oculi Ef regardless of the diopter of the eye E to be inspected. Therefore, when the focusing lens 3 is moved to match the focus of the photographing optical system with the fundus Ef, the illumination field diaphragm 21 is The illumination field diaphragm 21 is linked with the focusing lens 3 by the focus arm 33 so that the relay lens 19, the aperture mirror 2, and the objective lens 1 are conjugated with the fundus oculi Ef.
Move along.

The corneal baffles 17 and 18 and the crystalline lens baffles 23 and 24 are for removing harmful light such as flare light generated by the cornea Ec and crystalline lens of the eye E to be examined, and the pupil Ep of the eye E to be examined. Two types of light shield plates, large and small, are prepared according to the size of the, and are selectively used according to the shooting mode. If the pupil Ep has a normal size, the corneal baffle 17 and the crystalline lens baffle 24, which are large light shields for the normal photographing mode, are inserted into the optical path O4 and the fundus
In order to illuminate Ef widely, the diaphragm blade 21a is fully opened as shown by the solid line in FIG. Therefore, as shown in FIG. 4, the fundus image can be observed in the entire observation visual field V by the optometry e, and is recorded on the film 10 or the image recording device 57.

On the other hand, if the pupil Ep is small, the small pupil photographing mode is set, and the small-diameter corneal baffle 18 and the lens baffle 23 are respectively inserted in the optical paths, and the chain line in FIG. 3 separates harmful light from photographing light. Diaphragm blade 2 as shown
1a is narrowed down. Therefore, the illumination area on the fundus oculi Ef becomes narrow, the peripheral part of the observation visual field V is shielded from light as shown by the diagonal lines in FIG. 5, and the fundus image in a narrow range is observed by the optometry e, and this is photographed and the film 10 is taken. Alternatively, the image recording device 5
Recorded in 7.

Therefore, since the illumination area and the illuminance of the fundus Ef of the eye E are different between the normal photographing mode and the small pupil photographing mode, the CPU 51 determines the corneal baffles 17 and 18 and the crystalline lens baffle 23 depending on the photographing mode. 24, the size of the illumination field diaphragm 21 is adjusted, and the photographing light source 2
8. The light quantity of the observation light source 30 is adjusted. Furthermore, as shown in FIGS. 4 and 5, the recording range of the fundus image to be photographed is different, so the capacity of the frame memory in the image recording device 57 is adjusted according to the recording range.

6 and 7 are flow charts showing the control procedure of the CPU 51. The examiner selects the photographing mode with the input unit 55 according to the size of the pupil Ep of the eye E to be examined.
The input unit 55 is input only when the shooting mode different from the initial state is set. In step S1, the CPU 51 determines whether or not the photographing mode is changed based on the presence or absence of the input from the input unit 55. If there is no input from the input unit 55, it is determined that there is no change (NO), and the input standby state of the shooting button is set. If there is an input from the input unit 55, it is determined that there is a change (YES), and in step S2, it is determined based on the input from the input unit 55 whether or not the small pupil photographing mode is set. When it is determined that the normal photographing mode is selected (NO), the corneal baffle 17 including a large light shielding plate is inserted into the optical path 04 in step S3, and step S4
Then, the crystalline lens baffle 24 composed of a large light shielding plate is inserted into the optical path 04. In step S5, the light emission amount of the photographing light source 28 is changed to the normal photographing mode, and in step S6, the observation light source 30
Change the light intensity of for normal shooting mode.

Then, in step S7, the motor drive circuit 56
The control stepping motor 46 is driven to rotate by a predetermined rotation angle to widen the diameter of the illumination field diaphragm 21 and widen the photographing range. In step S8, the size information of the illumination field diaphragm 21 is transmitted to the image memory changing device 58. In addition, CPU
Reference numeral 51 monitors the size of the illumination field diaphragm 21 by detecting the rotation angle of the stepping motor 46. The image memory changing device 58 changes the capacity of the frame memory of the image storage device 57 based on this information so that all the fundus images shown in FIG. 5 can be recorded.

On the other hand, if it is determined in step S2 that the small pupil photographing mode is selected (YES), the corneal baffle 17 having a small light shielding plate is inserted into the optical path O4 in step S9, and the crystalline lens baffle 23 is inserted into the optical path in step S10. Insert in O4.

Further, in step S11, the amount of light emitted from the light source 28 for photographing is changed to that for photographing a small pupil, in step S12 the light amount of the light source 30 for observation is changed to one for observing a small pupil, and in step S13.
The motor drive circuit 56 is controlled by the stepping motor 6
6 is driven and rotated by a predetermined angle to narrow the illumination field diaphragm 21.

In this way, the corneal baffle 17 is replaced with 18,
The lens baffle 24 is changed to 23, and the illumination field diaphragm 2
Since the size of 1 is changed, the light blocking amount of the illumination light on the eye E is different from that in the normal shooting mode, but since the light amounts of the shooting light source 28 and the observation light source 30 are adjusted, regardless of the shooting mode. It becomes possible to observe and photograph the fundus image with a constant brightness.

However, since the recording range of the fundus image becomes narrower as shown in FIG. 5 than in the normal mode shown in FIG. 4,
The information to be recorded becomes smaller. Therefore, in this embodiment,
In order to effectively utilize the frame memory in the image storage device 57, the size of the memory area of the image storage device 57 used is changed according to the amount of information.

Therefore, in step S14, the size of the illumination field diaphragm 21 is transmitted to the image memory changing device 58. As shown in FIG. 5, the image memory changing device 58 sets the frame memory of the image recording device 57 more than the normal photographing mode so as to record only the fundus image information excluding the shaded portion shown by oblique lines from the observation visual field V. to shrink.

In step S15, the illumination field diaphragm 21 is set in the image memory changing device 58 in step S14 or step S8.
After transmitting the size information, or if the shooting mode is not changed in step S1, the CPU 51 enters a standby state for inputting the shooting button of the input unit 55. When the shooting button is pressed, the capture of the image in the image storage device 57 and the emission of the light source 28 for shooting are synchronized in step S16, and therefore it is possible to confirm whether or not the image storage device 57 is ready to capture the image. Check repeatedly until. When the preparation for image capturing is confirmed, the descending mirror 11 is retracted from the optical path O2 in step S17, and the photographing light source 28 is caused to emit a predetermined amount of light in step S18. As a result, the fundus image is captured by the television camera 15, captured in the image storage device 57, stored in the frame memory having a predetermined capacity, and displayed on the television monitor 59.

Although the capacity of the frame memory of the image storage device 57 is changed in accordance with the size of the illumination field diaphragm 21,
It may be changed in conjunction with the aperture mask, the field stop, etc. The size of the illumination field diaphragm 21 may be manually changed, or the size of the illumination field diaphragm 21 may be photoelectrically detected by a CCD or the like and changed in an electrically linked manner.

In this embodiment, the corneal baffle 17 is selected depending on whether or not the small pupil photographing mode is selected by the input unit 55.
Or 18, the lens baffle 23 or 24 is selectively inserted in the optical path O4, and the size of the illumination field diaphragm 21 is changed in two steps. A corneal baffle light shield plate and a lens baffle light shield plate are used. A plurality of two or more sheets are provided so that the pupil diameter of the eye to be inspected can be selected by the input unit 55, and a corneal baffle and a crystalline lens baffle made of light-shielding plates of appropriate sizes are interlocked with the input pupil diameter of the eye to be inspected. Each of them may be inserted into the optical path O4, and the size of the illumination field diaphragm 21 may be changed in multiple steps according to the number of options of the pupil diameter of the input unit 55.

[0031]

As described above, in the fundus image storage device according to the present invention, the recording range of the image to be recorded in the image storage means is changed in accordance with the size of the variable aperture, so that the small pupil diameter photography is performed. When the diaphragm is thus narrowed to narrow the recording range of the fundus image, the image area shielded by the diaphragm is not recorded, so that the storage area of the storage unit is not wastefully used.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment.

FIG. 2 is a partially enlarged view of an illumination field diaphragm.

FIG. 3 is a partially enlarged front view of an illumination field diaphragm.

FIG. 4 is an explanatory diagram of a fundus observation image in a normal photographing mode.

FIG. 5 is an explanatory diagram of a fundus observation image in a small pupil photographing mode.

FIG. 6 is a flowchart of a control procedure.

FIG. 7 is a flowchart of control means.

[Explanation of symbols]

9 shutters 10 Shooting film 12 eyepiece 17,18 Corneal baffle 15 TV camera 21 Illumination field diaphragm 21a Aperture blade 23, 24 lens baffle 28 Photographic light source 30 Observation light source 46 stepping motor 51 CPU 55 Input section 57 image storage 58 Image memory changing device 59 TV monitor

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-3-128038 (JP, A) JP-A-6-98859 (JP, A) JP-A-4-186480 (JP, A) JP-A-5- 199997 (JP, A) JP-A-4-71526 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61B 3/00-3/16

Claims (3)

(57) [Claims] 1. An illumination optical system for illuminating a fundus of an eye to be inspected,
A photographing optical system for photographing the illuminated fundus, a diaphragm for limiting a photographable range of the fundus provided at a position substantially conjugate with the fundus of the eye to be examined, and a diaphragm diameter varying means for changing the size of the diaphragm,
In a fundus image storage device having a fundus image storage means for electronically recording a fundus image, it is possible to change a recording range of an image to be recorded in the image storage means in correspondence with a size of the diaphragm. Characteristic fundus image storage device. 2. A normal photographing mode and a small pupil photographing mode
It has a switching means and responds to the mode switching by the switching means.
2. The fundus image storage device according to claim 1, wherein the size of the diaphragm is changed . 3. A crystalline lens bag according to the size of the diaphragm.
Full, corneal baffle, amount of light emitted from the light source for photography and observation light
The fundus image storage device according to claim 2 , wherein the light emission amount of the light source is switched .