JPS6227821B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ophthalmological camera that facilitates the operation of a barrier filter required when performing fluorescence fundus photography.

Fluorescent fundus photography, which is known as a type of ophthalmologic imaging, illuminates the fundus with blue excitation light, timing the time when a fluorescent agent injected from the cubital vein reaches the intraocular circulation system, and detects the blood vessels in the blood vessels. This is done by photographing the green-yellow fluorescence emitted by a fluorescent agent. At that time, the first
It is necessary to insert an exciter filter with wavelength versus light transmittance characteristics as shown in A in the figure into the illumination optical path, and a barrier filter with characteristics as shown in B in Figure 2 in the photographing optical path. be. but,
When both the exciter filter and the barrier filter are inserted, nothing can be visually recognized in the fundus image seen through the window until fluorescence begins to appear.
Since the illuminance of the fluorescent image is low even after the fluorescence has appeared, it is difficult to align and focus the ophthalmological camera with the fundus of the eye being examined, so we had no choice but to remove the barrier filter from the imaging optical path and perform the above-mentioned work. Must. Moreover, in this type of fluorescence fundus photography, dozens of images are taken every second to show how the fluorescence appears, so it is necessary to frequently insert and remove a barrier filter in order to align and focus the eye with the fundus. , the operation becomes extremely complicated.

An object of the present invention is to provide an ophthalmological camera that eliminates the above-mentioned troublesome operation and allows the barrier filter to be operated easily and reliably. In the camera, there is provided an operating means for inserting and removing a barrier filter into a photographing optical path, a means for causing a photographing light source to emit light at an arbitrary time after the barrier filter is inserted by the operating means, and an operating switch for controlling both of the means. The operating switch has a two-stroke operation structure, and the circuit is connected so that the first stroke inserts the barrier filter into the photographing optical path, and the second stroke causes the photographing light source to emit light. This is a characteristic feature.

The present invention will be explained in detail based on the embodiments shown in FIG. 2 and below.

FIG. 2 is a configuration diagram showing an embodiment of the optical system of an ophthalmological camera, and 1 is an observation light source consisting of a tungsten lamp, etc.
The light emitted from the is incident on a mirror 4 via a condenser lens 2a, a photographing light source 3 consisting of a xenon discharge tube, etc., and a condenser lens 2b, where it is deflected and sequentially transmitted to an exciter filter 5, a ring slit plate 6, and a relay lens. It reaches the perforated mirror 8 via 7a and 7b. Note that 9 is a reflecting mirror placed behind the observation light source 1 to collect and reflect the light from this lamp. The light that enters the perforated mirror 8 from the illumination optical system described above is reflected by the perforated mirror 8 in the direction of the eye E to be examined, illuminates the fundus Ef of the eye E, passes through the original optical path, and then returns to the perforated mirror 8. and reaches the observation optical system. An objective lens 10 is arranged between the perforated mirror 8 and the subject's eye E, and behind the perforated mirror 8, along the optical axis, there are a barrier filter 11, a focusing lens 12, a photographing lens group 13, and a movable lens group. A mirror 14, shutter 15, and photographic film 16 are arranged in sequence. On the reflection side of the movable mirror 14, a field lens 17, a mirror 18 for changing the optical path, and a finder 19 are arranged in sequence along the optical axis at a position conjugate with the photographic film 16. Note that e is the examiner's eye.

Here, the exciter filter 5 is inserted into the illumination optical path during fluorescence imaging by a drive mechanism (not shown), and removed from the optical path during other imaging, and its operation is confirmed by a microswitch S1. Also, barrier filter 1
1 is inserted into and removed from the photographing optical path by driving a solenoid 20.

This ophthalmological camera has an illumination light source 1 and a photographing light source 3.
is substantially conjugate with respect to the condenser lens 2a, the observation light source 1 is turned on during observation, and the photographing light source 3 is turned on instantaneously during photography. The light source image is once formed near the ring slit plate 6 by another condenser lens 2b, and then an image of the annular opening of the ring slit plate 6 is formed near the perforated mirror 8 by relay lenses 7a and 7b. The illumination light is reflected and travels to the left. Then, after forming an image of the annular aperture near the crystalline lens E1 of the eye E to be examined using the objective lens 10, the fundus Ef is illuminated.

The reflected light from the fundus Ef travels to the right and is once formed into an image by the crystalline lens E1 and the objective lens 10, then passes through the perforated mirror 8 and the photographic diaphragm (not shown), and is focused by the focusing lens 12 and photographic lens group 13. The image will be focused. During observation, the fundus image is guided upward by the movable mirror 14 located at the solid line position, and is observed by the examiner's eye e through the viewfinder 19. At the time of photography, the movable mirror 14 rotates to the dotted line position, and the fundus image is An image is formed on a photographic film 16 via an opened shutter 15.

3, 4, and 5 are cross-sectional views of a gripping rod 30 used by an examiner to operate an ophthalmological camera, and an operation button 31 is attached to the upper part of the gripping rod 30 so as to be movable up and down. There are three spring contacts below the operation button 31.
A switch S2 consisting of Sa, Sb, and Sc is provided. Figure 3 shows the state in which the operation button 31 is not pressed, Figure 4 shows the 1/2 stroke, and Figure 5 shows the conduction and non-conduction between the spring contacts Sa, Sb, and Sc of the switch S2 when the button is pressed for the full stroke. Indicates a conductive state. FIG. 6 is a block circuit diagram for controlling the operation of this embodiment, and the same reference numerals as in FIGS. 2 to 5 indicate the same members. 40, 41, and 42 are power supplies for the solenoid 20, observation light source 1, and photographing light source 3, respectively. The switch S2 is located inside the above-mentioned gripping rod 30, S1 is a micro switch that detects that the above-mentioned exciter filter 5 is inserted into the illumination optical path, and S3 is a manual switch consisting of two circuit contacts S3a and S3b for the barrier filter. The insertion changeover switch S4 is a switch operated by a relay 44. In order to light up the observation light source 1, a thyristor 45 and a unidirectional transistor (hereinafter referred to as
A trigger circuit 4 (abbreviated as UJT) 46 is inserted into the circuit, and a trigger circuit 4 for lighting the photographing light source 3.
7, a charging resistor 48 and a discharging capacitor 49 are provided.

When performing fluorescence fundus photography, first a fluorescent agent is injected into the subject, an exciter filter 5 is inserted,
The fundus Ef is illuminated with light shown in characteristic A in FIG.
At this time, the microswitch S1 for detecting the presence of the exciter filter 5 is turned on. A few seconds after injecting the fluorescent agent, wait until the fluorescent light is emitted from the fundus Ef, press the operation button 31 of the gripping rod 30 by 1/2 stroke as shown in Fig. 4, and press the contact Sa of the switch S2. When Sb and Sb are made conductive, the sixth
In the figure, an excitation current flows from a power source 40 to a solenoid 20, energizing the solenoid 20, and inserting a barrier filter 11 into the photographing optical path.

At the same time, the relay 44 is also energized, the switch S4 is switched to the normally open NO side, and the time constant for turning on the UJT 46 is reduced from the time constant R1・C1 of the resistor/capacitor circuit to R1・R2・C1/(R1+R2), and the switch S4 is switched to the normally open NO side. The timing at which the UJT 46 turns on in the output waveform of the power supply 41 shown in Fig. 7 is moved from point a to point b, and the thyristor 45
The thyristor 45 is turned on, and the energization time of the thyristor 45 increases from Ta to Tb shown in FIG. Therefore, the amount of light from the observation light source 1 increases, and in this state it becomes possible to observe and photograph a fluorescent image.

To take a picture, press the operation button 31 a further 1/2 stroke as shown in Fig. 5 to switch S2.
The contacts Sb and Sc of
9 is discharged and the photographing light source 3 emits light instantaneously. This completes one imaging session, but with fluorescence imaging, it is necessary to take several dozen images, so
It is necessary to check the EF and correct the positional deviation and focus deviation with the ophthalmological camera. With the barrier filter 11 inserted, only the fluorescent image of the fundus Ef is visible, and this fluorescent image is extremely weak and misaligned.
It is not possible to adjust the focus. When the user releases the operating button 31, the operating button 31 returns to the state shown in FIG. 3 due to the return force of the spring contact of the switch S2. In this state, the contacts Sa of switch S2,
Sb and Sc become non-conductive to each other, and solenoid 20
The excitation current is cut off and the barrier filter 11 leaves the photographing optical path. At the same time, the excitation current of the relay 44 is cut off, the switch S4 is switched to the normally closed NC side, and the time constant for turning on the UJT 46 is changed from R1・R2・C1/(R1+R2) to R1・C1.
In FIG. 7, the turn-on timing of the UJT 46 moves from point b to point a, the energization time of the thyristor 45 decreases from Tb to Ta, and the amount of light from the observation light source 11 decreases. In this state, the fundus Ef
Since the image can be observed, it is possible to adjust the positional shift and focus shift.

Furthermore, even when performing fluorescence photography while observing the fundus Ef, the entire stroke of the operation button 31 may be pressed at once. In this case, the barrier filter 11 is inserted into the photographing optical path by the switch S2 in the first 1/2 stroke to increase the amount of observation light, and the photographing operation is executed in the next 1/2 stroke. In addition, in FIG. 6, the exciter filter 5
When the microswitch S1 is not inserted, the microswitch S1 becomes non-conductive, and the excitation current to the solenoid 20 that causes the barrier filter 11 to be inserted is cut off.
The insertion operation of the barrier filter 11 is not executed, and the amount of observation light does not increase.

Next, we will discuss how to take pictures when fluorescence begins to appear from the fundus Ef. In this case, since continuous imaging is performed, it is necessary to observe and photograph only the fluorescent image.
In such a case, manually switch the insertion switch S3 of the barrier filter 11 to close the contact S3.
a, S3b to the normally open NO side. Then, the spring contact of switch S2 is activated by contact S3a.
Excitation current is applied to the solenoid 20 without passing through Sa and Sb, the barrier filter 11 is inserted into the photographing optical path, and the amount of observation light is also increased. At the same time, contact S3b is also switched, allowing current to flow between spring contacts Sb and Sc of switch S2. This means that the examiner should use the barrier filter 11.
By switching the insertion changeover switch S3,
Barrier filter 1 without pressing operation button 31
1 is inserted, the amount of observation light increases, and operation button 3
This means that you can shoot with 1 1/2 strokes. Once this continuous photographing time has elapsed, the subsequent photographing will take place every few tens of seconds to several minutes, and it is sufficient to return the insertion switch S3 of the barrier filter 11 to the original normally closed NC side.

As described above, in this embodiment, in order to eliminate the troublesome task of repeatedly inserting and removing the barrier filter 11 each time the positioning and focusing with the eye E is performed during fluorescence fundus photography, the operation button 3 is
The barrier filter 11 can be inserted/removed and the amount of observation light can be increased/decreased with just the operation 1 or, in the case of continuous shooting, with the insertion/removal switch S3 of the barrier filter 11, making it extremely easy to do so. It has the advantage of being able to perform fluorescence fundus photography. Furthermore, by providing a microswitch S1 that detects that the exciter filter 5 is inserted into the illumination optical path, erroneous fluorescence fundus photography without the barrier filter 11 being inserted can be eliminated. Also, in general color photography, the exciter filter 5 is not inserted, so the micro switch S
1 is non-conducting, and there is no risk that the barrier filter 11 will be accidentally inserted into the photographing optical path even when the operation button 31 is operated.

In the embodiment of the gripping rod 30 shown in FIG. 3, a spring contact is used for the structure of the switch S2, but a magnet may be provided at the bottom of the operation button 31 and reed switches may be used for the contacts Sa, Sb, and Sc. In addition, in the circuit diagram of FIG. 6, an electrical switch S3 is used as the insertion/switching switch for the barrier filter 11, but as shown in FIG. Even if it is inserted and removed between the lower flange of the operation button 31 and the cover of the gripping rod 30, the same effect as when using the insertion changeover switch S3 can be obtained.

As explained above, the ophthalmological camera according to the present invention allows easy insertion and removal of the barrier filter, and prevents film photography unless the barrier filter is inserted, thereby eliminating operational errors. be able to.

[Brief explanation of the drawing]

FIG. 1 is a characteristic diagram of an exciter filter and a barrier filter, FIG.
The figure is a sectional view of the gripping rod, Figures 4 and 5 are illustrations of its operation, Figure 6 is a block diagram of the operating circuit, Figure 7 is an illustration of the operation of the observation light source, and Figure 8 is an illustration of the other parts of the gripping rod. FIG. Reference numeral 1 is an observation light source, 3 is a photographic light source, 5 is an exciter filter, 8 is a perforated mirror, 10 is an objective lens, 11 is a barrier filter, 14 is a movable mirror, 16 is a photographic film, 19 is a viewfinder, 2
0 is a solenoid, 30 is a gripping rod, 31 is an operation button, and S1, S2, and S3 are switches.

Claims (1)

[Claims] 1. A camera that enables fluorescent ophthalmology photography,
It has an operating means for inserting and removing the barrier filter into the photographing optical path, a means for causing the photographing light source to emit light at an arbitrary time after the barrier filter is inserted by the operating means, and an operating switch for controlling both of the means, The operating switch has a structure that operates in two strokes, and the circuit is connected so that the barrier filter is inserted into the photographing optical path during the first stroke, and the photographing light source is emitted during the second stroke. camera. 2. The ophthalmological camera according to claim 1, further comprising actuating means for performing the first stroke operation of the operation switch in order to constantly insert the barrier filter into the photographing optical path. 3. The ophthalmological camera according to claim 1, wherein the amount of illumination light from the observation light source is increased in conjunction with the first stroke operation of the operation switch. 4. The ophthalmological device according to claim 3, wherein the barrier filter operating means includes means for increasing the amount of illumination light from the observation light source when the barrier filter is inserted into the photographing optical path. camera. 5. The ophthalmological camera according to claim 1, wherein the barrier filter operating means prohibits insertion of the exciter filter into the illumination optical path when the exciter filter is removed from the illumination optical path.