JPH0255031A - Ophthalmic device - Google Patents

Abstract

PURPOSE:To protect a human eye when an excess illumination light quantity is continuously given to the human eye by providing an illumination light source control means controlling the illumination light quantity when the light quantity accumulated output exceeds the human eye illumination safety allowable accumulated light quantity. CONSTITUTION:If the illumination light quantity a>a0 (a0 is a limiting quantity of illumination light without injuring human eye), the illumination light quantity detection output (a) is outputted from a safety quantity correcting circuit 26 to a safety quantity comparison control circuit 12, the safety quantity comparison control circuit 12 selects the human eye illumination safety allowable accumulated quantity at' obtained from the product of the illumination light quantity (a) and the allowable illumination time (t) based on a human eye illumination safety allowable accumulated lithe quantity curve A and the illumination light quantity detection output corresponding to the illumination light quantity (a). The safety quantity comparison control circuit 12 compared the human eye illumination safety allowable accumulated light quantity at' and the accumulated light quantity and outputs the control signal to a driving circuit 10 when the accumulated light quantity exceeds the human eye illumination safety allowable accumulated light quantity at'. The driving circuit 10 is excited and controlled so as to protect the human eye based on the control signal, an illumination light source is stopped to be illuminated.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an ophthalmological device.

(Prior art) When observing and photographing five eyes, an ophthalmological machine guides the illumination light flux from the illumination light source to the human eye through an optical system to illuminate the human eye, but the amount of illumination light exceeds a certain limit. If continuous illumination is applied to the human eye, the first human eye will be damaged. The relationship between this human eye illumination light amount and the time until damage occurs when this human eye illumination light amount is continuously applied to the human eye is known as the human eye illumination safe allowable accumulated light amount curve A shown in Figure 1. ing. In FIG. 1, the horizontal axis shows the allowable illumination time t, the vertical axis shows the illumination light amount W, and the product Wt of these is the human eye illumination safety allowable accumulated light amount.

As is clear from this human eye illumination safety allowable accumulated light amount curve A, when the illumination light -i is below a certain limit (the illumination light amount aO or less), the human eye can emit light for a substantially infinite period of time.

Even if it is exposed to illumination, it will not cause any damage.

Here, "substantially" means compared to the time required for observation and photographing using an ophthalmological machine.

Conventionally, the human eye is illuminated using an illumination light amount below this certain limit (the illumination light amount aO or less), and the human eye is illuminated and photographed, or the human eye is illuminated for a very short period of time and the photograph is taken. Therefore, it was unnecessary to take this human eye illumination safe allowable accumulated light amount curve A into consideration.

(8 Problems to be Solved by the Invention) However, when observing or photographing, a situation arises in which it is desired to continuously apply an excessive amount of illumination light above a certain limit (illumination light amount of 80 or more) to the human eye while observing or photographing. In some cases. For example, with a fundus camera used as an ophthalmological machine, there are cases where it is desired to perform ICG photography when taking fluorescent fundus photography.
During G photography, the amount of light at the excited wavelength is weak and T
Since the light-receiving sensitivity of the V-camera is also low, it is necessary to continuously provide the second eye with an excessively illuminated scene exceeding a certain limit, and there is a risk that the human eye may be damaged by the illumination.

The present invention has been made in view of the above circumstances.

The purpose is to provide an ophthalmologic apparatus that can protect the human eye when an excessive amount of illumination light exceeding a certain limit is continuously applied to the human eye.

(Means for Solving the Problems) In order to achieve the above object, the ophthalmological device according to the present invention has the following features:
An illumination light source for human eye illumination, an illumination optical system that guides the illumination light flux of the illumination light source to the human eye, an illumination light amount detection means for detecting the amount of illumination light to the human eye, and an illumination light amount detection output of the illumination light amount detection means. and an illumination light amount integrating means for integrating the illumination light amount, and a light amount integrated output of the illumination light amount integrating means and a human eye illumination safety allowable accumulated light amount, and when the light amount integrated output exceeds the human eye illumination safety allowable accumulated light amount, the above-mentioned and illumination light source control means for controlling the amount of illumination light so as to protect human eyes.

(Operation and Effect) According to the present invention, the illumination light amount detection output of the illumination light amount detection means is integrated by the illumination light amount integration means, and the illumination light source control means combines the illumination light amount integration output of the illumination light amount integration means with the human eye illumination safety tolerance. Compare the amount of accumulated light.

The illumination light source is controlled so as to protect one human eye when the light amount integrated output exceeds the human eye illumination safety allowable accumulated light amount. Therefore, when an excessive amount of illumination light exceeding a certain limit is continuously applied to the human eye, the illumination light amount is controlled by comparing the integrated output of the illumination light amount with the human eye illumination safety allowable accumulated light amount, and the illumination light source Even if the amount of illumination light fluctuates due to variations in brightness, etc., changes in characteristics of optical elements constituting the illumination optical system, damage to the human eye can be reliably prevented.

(Example) Hereinafter, an example in which an ophthalmologic apparatus according to the present invention is applied to a fundus camera will be described with reference to the drawings.

2 to 5 show a first embodiment of the ophthalmological apparatus according to the present invention. In FIG. 2, 1 is an illumination optical system, 2 is a photographing optical system, and E is a human eye. The illumination optical system 1 includes an illumination light source 3 for human eye illumination. It has a collimating lens 4, an exciter filter 5, a ring diaphragm 6, a half mirror 7, a total reflection mirror 8, and a perforated mirror 9. The illumination light source 3 is driven by a drive circuit 10. This drive circuit 10 is controlled by a control device 11 as an illumination light source control means, and a safety amount ratio diaphragm control circuit 12. It has a switch 15 and a foot switch 16.

Is the pedestal position detection switch 13 illuminating the left eye?
A switch to detect whether the right eye is illuminated.
This is a switch that is turned on when a pedestal (not shown) is moved to a position corresponding to the left or right eye. The barrier filter detection switch 14 is a switch that is turned on when the barrier filter 5' of the photographing optical system 2 is inserted into the optical path of the photographing optical system 2. The eye to be examined fixed position detection switch 15 is a switch that is turned on when the human eye is located at a predetermined position.For this eye to be examined fixed position detection switch, a switch is used for the chin rest, and a switch for the chin rest, for example. The foot switch 16 is a switch that is provided at the foot and turns on when stepped on.

As shown in FIG. 3, the gantry position detection switch 13 is connected to the right eye detection switch 17. It consists of a left eye detection switch 18. This right eye detection switch 17, left eye detection switch 1
8 is input to the OR circuit 19.

The output of the OR circuit 19 is input to one input terminal of the three-person couple circuit 20, and the outputs of the eye fixed position detection switch 15 and the barrier filter detection switch 14 are input to the other input terminals of the three-person couple circuit 20. . The three-person AND circuit 20 has a function of outputting a switching signal to the ICG switching circuit 21 when all outputs of the switches 13, 14, and 15 are high (on).

■The CG#J switching circuit 21 is configured to control the drive circuit 1 so that a high illuminance light amount exceeding a certain limit is generated from the illumination light 'g3.
0, and the drive circuit 10 so that the illumination light source 3 generates a low illuminance light amount below a certain limit.
The drive circuit 10 has a function of switching the drive circuit 10 between the normal mode and the normal mode.

Note that the foot switch 16 has a function of turning the drive circuit 10 on and off.

Therefore, according to this control device 11, even if the foot switch 16 is inadvertently stepped on, the drive circuit 10 will not switch to the ICG mode unless the barrier filter 5' is inserted into the optical path of the photographing optical system 2. For,
Damage to the human eye E due to careless operation can be prevented.

The illumination light beam from the illumination light source 3 is focused by a collimator lens 4, and when an exciter filter 5 is inserted in the optical path, a light beam having a wavelength corresponding to the characteristics of the exciter filter 5 is guided to a ring diaphragm 6. The ring diaphragm 6 is arranged at a substantially conjugate position with the pupil of the human eye E, and has a ring-shaped transmitting part 6a and light shielding parts 6b and 6c, as shown in FIG.

The illumination light flux transmitted through the ring-shaped transmission part 6a is incident on the human eye E as ring light P via a half mirror 7, a total reflection mirror 8, a relay lens 8', and a perforated mirror 9.
The fundus F is illuminated.

The fundus reflected light from the fundus F passes through the hole 9a of the perforated mirror 9 and is guided to the imaging lens 22. During fluorescence fundus photography, a barrier filter 5' is placed in the optical path of the photographic optical system 2. The fundus image is taken by the TV camera 23. Note that a fluorescent agent is injected into the subject in advance for fluorescence fundus photography.

The half mirror 7 has a function of reflecting a part of the illumination light beam that has passed through the ring diaphragm 2 toward the total reflection mirror 24 . A detection sensor 25 serving as illumination light amount detection means is provided in front of the total reflection mirror 24 in the reflection direction. The illumination light amount detection output of this detection sensor 25 is input to a safety and correction circuit 26. Note that 27 is a support member for the detection sensor 25.

The safety and correction circuit 26 is turned on by the control table @11. This safety and correction circuit 26 is connected to a light amount integrating circuit 28 as a light amount integrating means when an illumination light amount detection output exceeding a certain limit (illumination light 'taO or more) is input based on the human eye illumination safety allowable accumulated light amount curve A. The illumination light amount detection output is output to the comparison control circuit 12. That is, when the illumination light amount is less than aO, the safety and correction circuit 26 prohibits the illumination light amount detection output from passing through. Note that a pair of light amount integration circuits 28 are provided corresponding to the left eye and the right eye.

Like the safety and correction circuit 26, it is turned on by the control table [11]. The light amount integration circuit 28 outputs a light amount integration output to the memory 29. The memory 29 has its contents reset by the control device 11, and stores the light amount integrated output each time the light amount integrated output is input. The output of this memory 29 is input to the safety and comparison control circuit 12 and a bar graphic LED 30 as a warning/display means. A pair of memories 29 are provided similarly to the light amount integrating circuit 28.

As shown in Fig. 5, the bar graphic LED 30 is color-coded and has other features so that safe areas and dangerous areas can be identified. You can check the difference between the allowable accumulated light amount and the cumulative illumination light amount that actually illuminates the human eye, and you can safely perform human eye illumination when illuminating with an illumination light amount above a certain limit (illumination light amount aO or more). be able to. You can also check how much safety margin there is, so if you want to alternate between right-eye and left-eye illumination, for example, you can round up right-eye illumination midway through, shift to left-eye illumination, and then return to left-eye illumination. If you want to do this, the bar graphic LED shows how much safety margin there is for the left eye.
This can be confirmed by 30.

The safety and comparison control circuit 12 selects the safe allowable accumulated light amount for human eye illumination based on the illumination light amount detection output of the safety and correction circuit 26 and the human eye illumination safe allowable accumulated light amount curve A. For example, as shown in FIG. 1, if the illumination light intensity is a > a O, the illumination light intensity detection output a is output from the safety and correction circuit 26 to the safety and comparison control circuit 12, so that the safety and The comparison control circuit 12 is based on the human eye illumination safety allowable accumulation light amount curve A and the illumination light amount detection output corresponding to the illumination light amount a, and the human eye illumination value given by the product of the illumination light amount a and the allowable illumination time t' corresponding to the illumination light amount a. Lighting safety tolerance Mt & light amount at
'Select. Then, the safety and comparison control circuit 12 compares this human eye illumination safety allowable accumulated light iat' with the integrated light amount, and the integrated light amount is the selected human eye illumination safe allowable accumulated light 5ka.
When t' is exceeded, a control signal is output to the drive circuit 10.

The drive circuit 10 is energized based on this control signal so as to protect human eyes. Here, the drive circuit 10 is deactivated and the illumination light source 10 is stopped from emitting light.

Note that in this embodiment, the amount of illumination light incident on the single person's eye E and the amount of light incident on the detection sensor 25 do not match, but since the correspondence can be established in advance, there is no problem in detecting the amount of illumination light.

FIG. 6 shows a second embodiment of the ophthalmological device according to the present invention,
In place of the total reflection mirror 8, a half mirror 7 is provided at the position where the total reflection mirror 8 was provided, and a detection sensor 25 is provided behind it, thereby simplifying the configuration of the illumination optical system 1.

FIG. 7 is a diagram showing a third embodiment of the ophthalmological apparatus according to the present invention, in which the half mirror 7 shown in FIG. 2 is replaced by a ring diaphragm 6.
In addition, an elliptical transmitting portion 7a is formed in the half mirror 7, and the ring diaphragm 6 is eliminated. Note that 7b and 7c are light shielding parts. Since the half mirror 7 is disposed obliquely to the optical axis, the illumination light flux that has passed through the elliptical transmission section 7a becomes ring light P when passing through the pupil of the human eye.

Although the embodiments have been described above, the present invention is not limited thereto and includes the following.

In the embodiment, the drive circuit 10 is controlled so that the illumination light source 3 stops emitting light when the accumulated light amount exceeds the selected human eye illumination safety allowable accumulated light amount at', but the shutter is not connected to the illumination optical system. It may be inserted into the optical path of
Alternatively, the lighting may be switched from high-intensity lighting to low-intensity lighting.

[Brief explanation of the drawing]

Figure 1 is a diagram of the human eye illumination safety allowable accumulated light amount curve. 2 to 5 are diagrams for explaining a first embodiment of the ophthalmologic apparatus according to the present invention, and FIG. 2 is an overall configuration diagram thereof. Figure 3 is a block circuit diagram of the control device shown in Figure 2, Figure 4 is a plan view of the ring aperture shown in Figure 2, Figure 5 is an enlarged view of the bar graphic LED shown in Figure 2, and Figure 6. FIG. 7 is an optical system diagram showing a second embodiment of the ophthalmologic apparatus according to the present invention, and FIG. 7 is a plan view of a half mirror used to explain the third embodiment of the ophthalmologic apparatus according to the present invention. 1... Illumination optical system 2... Photography optical system 3... Illumination light source 5'... Barrier filter 11... Control device 12... Safety amount specific aperture control circuit, 13... Mount position Detection switch 14...Barrier filter detection switch 15...Eye fixed position detection switch 25...Detection sensor 26...Safety amount correction circuit 28...Light amount integration circuit 30...Bar graphic LED 4th Diagram: human eye

Claims (1)

[Scope of Claims] (1) An illumination light source for illuminating the human eye, an illumination optical system that guides the illumination light flux of the illumination light source to the human eye, and an illumination light amount detection means for detecting the amount of illumination light for the human eye; An illumination light amount integrating means for integrating the illumination light amount detection output of the illumination light amount detecting means compares the light amount integrated output of the illumination light amount integrating means with the human eye lighting safety allowable accumulated light amount, and the light amount integrated output is determined as the human eye illumination safety. An ophthalmological apparatus comprising an illumination light source control means for controlling an illumination light amount to protect the human eye when the amount of accumulated light exceeds an allowable accumulated light amount. (2) The ophthalmology according to claim 1, wherein the illumination light source control means cuts off the illumination light from entering the human eye when the light amount integrated output exceeds the illumination safety allowable accumulated light amount. Device. (3) The ophthalmological apparatus according to claim 1, wherein the illumination light source control means stops the light emission of the illumination light source when the light amount integrated output exceeds the human eye illumination safety allowable accumulated light amount. . (4) The illumination light source control means is characterized in that the illumination light source is automatically switched from high-intensity illumination to low-intensity illumination when the light amount integrated output exceeds the human eye illumination safety allowable accumulated light amount. The ophthalmological device according to claim 1. (5) The illumination light source control means includes a pedestal position detection switch for detecting whether the human eye is the left eye or the right eye, and detecting whether the human eye is at a predetermined position. and a barrier filter detection switch for detecting whether or not a barrier filter is inserted into the optical path of the photographing optical system. The ophthalmologic apparatus according to claim 1, wherein the ophthalmologic apparatus switches from low-intensity illumination to high-intensity illumination when both the detection switch and the barrier filter detection switch are on. (6) An illumination light source for illuminating the human eye, an illumination optical system that guides the illumination light flux of the illumination light source to the human eye, an illumination light amount detection means for detecting the amount of illumination light to the human eye, and illumination of the illumination light amount detection means an illumination light amount integrating means for accumulating the light amount detection output; and an illumination light amount integration means that receives the illumination light amount detection output and determines whether or not the illumination light amount detection output exceeds a certain limit based on a human eye lighting safety allowable accumulated light amount curve; A safety amount correction circuit outputs the illumination light amount detection output to the illumination light amount integration means when the above illumination light amount detection output is input; Select a human eye illumination safety allowable accumulated light amount according to the light amount detection output, compare the light amount integrated output with the selected human eye illumination safe allowable accumulated light amount, and determine the human eye illumination safe allowable accumulated light amount selected by the light amount integrated output. An ophthalmological apparatus comprising: an illumination light source control means for controlling the illumination light amount so as to protect the human eye when the light amount exceeds the illumination light amount. (7) An illumination light source for illuminating the human eye, an illumination optical system that guides the illumination light flux of the illumination light source to the human eye, an illumination light amount detection means for detecting the amount of illumination light to the human eye, and illumination of the illumination light amount detection means An illumination light amount integrating means that integrates the light amount detection output, and when the light amount integrated output of the illumination light amount integrating means and the human eye lighting safety allowable cumulative light amount exceeds the human eye lighting safety allowable light amount. An ophthalmological device comprising a warning/display means for warning/displaying a warning to an examiner.