JPS5962029A - Ophthalimic observing and photographing apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ophthalmological observation and photographing apparatus, and more particularly to an apparatus capable of fluorescent ophthalmological observation or photographing.

Fluorescent ophthalmology observation and photography technology involves intravenously injecting a fluorescent agent into blood vessels, exciting and irradiating the fundus with short wavelength light, and observing or photographing the fundus using the fluorescent light (long wavelength light) from the fluorescent agent. Already known.

Unlike the conventional technique of picking up the reflection of light irradiated to the fundus, this fluorescent ophthalmological observation photographing allows a fundus image with a high BlN ratio to be obtained because the light is emitted from the limited blood vessels.

However, in fundus observation photography, the above-mentioned observation photography using fluorescent light is not always performed, and it is common to use it in combination with a conventional ophthalmological observation photography method.

However, when switching from a normal ophthalmological observation and photographing method to an ophthalmological observation and photographing method using fluorescent light, there is a problem in that the amount of light for observation or photographing is reduced.

This occurs because the amount of transmitted light is reduced by using an exciter filter that transmits only excitation light from the irradiation light source for observation or photography, and a barrier filter that transmits only fluorescence from the fundus. This is a problem.

A button to solve this problem is to increase the light intensity of the irradiation light source when observing or photographing with fluorescent light, for example, by operating the observation or photographing light volume knob to increase the era name until the appropriate light t is reached. It is conceivable to aim for this.

In order to efficiently perform the conversion between light and light, it is already known to operate a microswitch in conjunction with the movement of an exciter filter into and out of the optical path to automatically increase and decrease the amount of light.

However, such mechanical actuation remains problematic in terms of durability.

In view of the above points, it is an object of the present invention to provide a J-class observation and photographing device that can automatically increase and decrease photoelectric power in conjunction with the movement of an exciter filter into and out of an optical path.

This is achieved by photoelectric detection using wavelength division through a filter having a characteristic of cutting off light transmitted through an exciter filter.

According to the present invention, the amount of light for observation or photography can be changed automatically and stably in conjunction with the movement of the exciter filter into and out of the optical path, which is convenient for the observer or photographer.

Examples of the present invention will be shown below.

FIG. 1 shows an embodiment of the invention.

Reference numeral 1 indicates an observation lamp, and reference numeral 2 indicates a photographic strobe lamp, which are arranged conjugately with a condenser lens 4.

6 is a condensing mirror for efficient illumination.

In the case of normal observation, the light emitted from the observation lamp 1 is imaged at the center of the light source of the photography strobe lamp 2 by the condenser lens 4; ] Ring slit plate 6 having
．． imaged on top.

The ring slit plate 6 becomes conjugate with the center of the perforated mirror 8 having a central aperture 8a through the relay lens 7, and fourthly with the pupil Hp of the eye E to be examined through the objective lens 9. As a result, a ring-shaped light source image is formed in the pupil, which diffuses and uniformly illuminates the fundus Er.

The light from the fundus Er passes through the center of the ring illumination, enters the objective lens 9 again, and enters the central aperture 8a of the perforated mirror 8](
(1) The optical path is changed by the flip-up mirror 12 placed in the optical path, and the image is formed on the field lens 14 by the imaging lens 10.11.
A fundus image is observed through 6.

When photographing, the photography strobe lamp 2 is emitted instead of the observation lamp 1, and the flip-up mirror 12 is flipped up.
A fundus image is formed on the film 13. In addition, when shooting,
By causing the light source 22 to emit light, the data 23 of the data imprinting section' can be imprinted on the film 13 together with the fundus image through the lens 24 and the mirror 25.

The above is the case of normal observation photography, but below, the case of fluorescence observation photography will be explained.

An exciter filter 17 is provided in the vicinity of the ring slit plate 6 in the optical path, and transmits only a predetermined short wavelength light of the light source light. The transmittance characteristics of the exciter filter 17 are shown in FIG. 2(a).

The illumination light transmitted through the exciter filter 17 is the fundus Er.
The fluorescent substances in the blood vessels are excited and emit fluorescent light.

In the photographing optical path, a barrier filter 18 is provided between the perforated mirror 8 and the imaging lens 10, and the barrier filter 18 only transmits fluorescent light from the fundus. The transmittance characteristics of the barrier filter 18 are shown in No. 21MHb), and the transmittance characteristics of the exciter filter 17 shown in FIG.
does not overlap with the transmittance characteristics of As a result, the light reflected from the fundus periphery of the fundus illumination light is filtered through the barrier filter 1.
8, a fundus image with a high S/N ratio can be observed and photographed.

Now, in the present invention, in order to compensate for insufficient light intensity during fluorescence observation photography, the optical fiber 19 receives the light flux passing through the ring slit plate 6, and the detection filter 20,
guided to a photodetector 21. The transmittance characteristics of the detection filter 20 are those that transmit long wavelength light as shown in FIG. 2(C), and do not overlap with the transmittance characteristics of the exciter filter 17 shown in FIG. 2(a). It is. Therefore, when the exciter filter 17 is in the optical path, the photodetector 21 has no optical output and is in an off state.

On the other hand, when the exciter filter 17 is located outside the optical path, the long wavelength components of the light source light pass through the detection filter 20 and
Since the light enters the photodetector 21, the photodetector 21 is turned on.

In this way, the presence or absence of the exciter filter 17 in the optical path is detected as the presence or absence of the output of the photodetector 21.

Can be changed dynamically.

An embodiment of the light amount control circuit is shown in FIG. 3 below.

27 is a waveform shaping circuit that binarizes the output of the photodetector 21;
Reference numeral 28 denotes a time constant switching circuit, in which a double time constant υ is set according to the output polarity of the waveform shaping circuit 27.

That is, for example, if the input polarity to the time constant switching circuit 28 is
When the input polarity is "0", the time constant is set smaller, and when the input polarity is "1", a much larger time constant is set.

29 is a gate trigger circuit, and a time constant switching circuit 28
As an integral circuit (loop), a trigger pulse is applied to a current control circuit 30 using Xyrisk. Note that 31 is a power source for lighting the light sources 2 and 3, which is obtained by single-phase rectification of an AC power source.

Here, when the exciter filter 17 is outside the optical path, the photodetector 21 is in an on state, and the waveform shaping circuit 27 outputs a level "1". At this time, the time constant switching circuit 2 is set to a time constant that provides a phase θ1 as shown in FIG. For this reason, the gate trigger circuit 29 outputs a trigger pulse to the gate of the current control circuit 30 after an integration time t1 corresponding to θ1 for each AC cycle.

Therefore, the light source 2.3 is energized and illuminated only during the time period shown by the shaded area in FIG. Next, exciter filter 17
enters the optical path, the photodetector 21 turns off, and the output level of the waveform shaping circuit 27 becomes 0''. In this case,
The time constant switching circuit 28 has a phase of θ2 as shown in FIG.
Since the time constant is set to give , after the gate trigger circuit 29 and current control circuit 30 operate in the same manner as described above, the light source is energized for a time period corresponding to the shaded area in FIG.

As a result of the above, the amount of light emitted by light sources 2 and 3 is equal to
By entering the filter 17 into the optical path, (θ1-θ2
) is increased by an amount corresponding to the phase difference. As a result, normal observation photography and observation photography using fluorescent light can be performed with an appropriate amount of light. Note that it is of course possible to add a minute light amount adjustment means to the simple two-stage switching.

FIG. 6 shows a different embodiment of the light amount control circuit.

Reference numeral 32 denotes a manual setting device for manually varying the light intensity setting of the light source, which is composed of, for example, a variable resistor and includes a time constant switching circuit 28.
connected to. Reference numeral 33 denotes a signal line on/off switch, which controls on/off of the signal output of the waveform shaping circuit 27.

The opening/closing control of the switch 33 is controlled in conjunction with the manual setting device 32, so that if the time constant set by the manual setting device 32 is smaller than a predetermined amount, the switch 33 remains on, and a time constant larger than the predetermined amount is set. is configured to be in the off state when the In other words, the switch 33 is normally in the on state and controls the light amount in conjunction with the operation of the photodetector 21, but the manual setting device 32 is set in the direction of narrowing down the light (3) (the direction with a large time constant) K.
When the set time constant becomes larger than a predetermined amount due to the operation, the switch 33 is turned off and control of light generated by the operation of the photodetector 21 is prohibited. Here, the time constant switching circuit 28
It is assumed that the input circuit for the light/shadow detection signal is constituted by an OR circuit that can maintain the logic level "1" even when the switch 33 is turned off.

With the above configuration, in the manually adjustable light amount control circuit 26, even if the exciter filter is in the optical path, the incident light to the photodetector 21 decreases when the light purity setting is extremely low [7, This prevents collisions in which the exciter filter is located outside the optical path and the discriminator tjB.

In addition, in the explanation of H below, the exciter filter 1
7. The (Yγ position) in the optical path of the barrier filter 18 is not limited to the illustrated position.
It is advantageous that t does not increase the size of the filter.

Furthermore, although the insertion of the exciter filter is detected photoelectrically and the observation light intensity or photographing light intensity is automatically changed in the above description, it is of course also possible to automatically change the light intensity for data capture. . Furthermore, although Optical Fine-19 is shown as the light guiding member, similar materials such as rod-shaped lenses or Self-Oak (trade name) may be used, and furthermore, it may be used as a compound eye optical system.

As described above, according to the present invention, since the amount of light for observation and photographing is automatically switched when the exciter filter is inserted, it is possible to realize an ophthalmological observation and photographing apparatus that is convenient for operation.

[Brief explanation of drawings]

Figure 1 is a diagram of an embodiment of the present invention, Figure 2 (a), (b), and (C) are diagrams of transmittance characteristics of an exciter filter, barrier filter, and detection filter, respectively. The figure shows the first part of the light amount control circuit. FIGS. 4 and 5 are gate trigger phase diagrams of the second embodiment, respectively. In the figure 1...Observation light source 2...Machine light source 17...Exciter filter 18...Barrier filter 19...Optical filter 20...Detection filter 21...Photodetector 26...light control circuit 20 right side 7

Claims (1)

[Claims] 1. In an apparatus capable of observing and photographing a fundus image using fluorescence by inserting an exciter filter into the optical path, a light source for observation or H1 photography, an exciter filter, and a photodetector are arranged in this order, A filter having a characteristic of cutting the transmitted light of the exciter filter is provided in front of the detector,
An ophthalmological observation and photographing apparatus characterized in that the presence or absence of insertion of an exciter filter into an optical path is detected based on the output of the photodetector. 2. Determine the output of the photodetector and determine whether at least ? 1.
The ophthalmological observation and photographing apparatus according to claim 1, further comprising a light quantity control means for changing the light intensity of the light source for IN festival or photographing. 5. The ophthalmological observation and photographing apparatus according to claim 2, which photoelectrically detects insertion of the exciter filter and automatically changes the observed or photographed scene. 4. Claim f' in which the light flux from the exciter filter is guided to a photodetector through an optical fiber.
The ophthalmological observation and photographing device described in Section R1. 5. The ophthalmological observation and photographing apparatus according to claim 2, wherein the light amount control means includes means for prohibiting output discrimination in a predetermined state. The ophthalmological observation and photographing apparatus according to claim 2, wherein the insertion of the exciter filter is photoelectrically detected and the amount of light for data imprinting is automatically changed.