JPH0315436A - Allowable minimum pupil diameter contracting optical system for eyeball function measuring machine - Google Patents

Abstract

PURPOSE:To sufficiently reduce minimum pupil diameter by adding an optical system for making the enlarged image of an eye with preserving optical properties between a projecting system in an eyeball function measuring machine and the eye. CONSTITUTION:When a lends L3 (f3=f) and a lens L4 (f4=f/2) are disposed, a light emitted from a point B is collected to a point D, and the parallel light in the point B remains parallel also in the point D, so that an optical relay system nearly preserving optical properties can be constituted. In this optical relay system, the width of the parallel light in the point B is halved, and the magnification vertical to the optical axis of the image in the point B is halved. Contrary to this, when an eye is put on a point D, an image with the doubled size of the eye is formed on the point B by the optical relay system. When the eye is focused to a target T placed in a position moved from the focus position A of a lens L2 by (x), the target T is seen from the point B as situated in the position of f<2>/x. Then, when the lens L3 acts on this image, the target T is seen from the point D as situated in the position of (f/2)<2>/x. Only by quadrupling a measurement value obtained by adding such an optical relay system, the minimum pupil diameter is halved, and the values of refraction and regulation can be easily measured.

Description

[Detailed Description of the Invention] [Field of Application in Industry] The present invention relates to the measurement of the minimum allowable pupil diameter reduction for an ocular function measuring device suitable for use in measuring the ocular function of young people and middle-aged and elderly people. There is something about cell yarn.

[Conventional technology: Older age, older age, triflux meter, three-dimensional offtometer, etc., make it easy to adjust and adjust the eye's nostrils.
However, due to the power and size limitations of the LED used for measurement, the small pupil diameter that can be measured is now . 3
It is about mm.

If you are a healthy young person or are looking at the far point (the furthest point you can see), almost all of them have a pupil diameter of 3+nm or more, so the above minimum pupil diameter is not a problem. In general, young people, middle-aged people, and elderly people often have pupil diameters of 3 mm or more even when looking at a far point. Furthermore, when you adjust your eyes and look close, it's 1il! The diameter of the pupils is often less than 3mm, even in adolescents. Therefore,
It is strongly desired that the minimum allowable pupil diameter be reduced to about 1.5 mm, which is about half of the current value.

This will be explained in more detail with reference to FIGS. 4 to 6.

Figure 4 shows the optical system of the existing O-1 refractometer, and Figure 5 shows the original J! refractometer. lj is shown. The optical system shown in these figures includes a lens Ll, a tire flam (small hole) D, a lens L2, and a beam splitter B.
As shown in FIG. 6, two lights IP. I made a statue of an LED.
The measurement light is irradiated onto the retina through the window D and A1η is added. Therefore, as the pupil becomes smaller, the amount of light measured decreases.
Since measurement errors occur, the minimum pupil diameter is determined by the size of the image.

The light-receiving measuring device of this Saiichi Trifrac 1-meter receives the reflected light from the fundus of the eye and performs the necessary measurements.
5-L7, L9. Through an optical system equipped with a lens 1.8 etc. controlled together with the tire flamm D,
projected onto the top. The sunspot distance is written in parentheses for each lens in the figure.

To give an overview of the measurement using the helifractometer, first, two lights, $tl. l: The image of D comes to the cornea, and through that window, the image of tire flam D comes to the retina. 1. Accurately position the image by the lens 1.2 of the eye e or tire frame D. When aligning the tζ point, the two light sources of the tire flam D1. F. The image obtained by D is formed as a single point on the retina.

Focal length ft from lenses 1 and 2? The tire diaphragm D located at the side A, which is a distance of 100 m, is moved 1 x distance from that position toward the lenses 1 and 2, and the lens diaphragm D of the tire diaphragm D is moved from that position by 1 x distance. ．． ? If you focus accurately on the image according to c, you will see a mesh of 1! “The first image comes from a point E, which is a focal length #f away from the lens L7, at a position roughly X distance away in the direction of the lenses 1 and 7.

Therefore, according to the movement of the tire solum D, the lens L8 is
If you move it to the 7 side, the conjugate image of the retina will appear on the cell PC. Therefore, Fusai 1 ~ Cell PC
Above is the retinal image of Tire Solar l\D, so that it becomes a point.
Tire flam D and lenses 1 and 8 must be linked to move and move? The amount of adjustment can be measured from X.

As mentioned above, in the optical system of an autorefractometer, two light sources L. E
The minimum pupil diameter is determined by the size of the image of D. In the current model, the center distance between the two light source LEDs is approximately 4 mm.
By setting l f2 = f + > f 2 and creating an image on the cornea that is half the size of the light source PoD, the minimum pupil diameter is set to about 3 + no + and 1S
．． : ゛shi.

;,,''j Is it possible to easily halve this minimum pupil diameter by further doubling the focal length of r2? In this case, the amount of available light is proportional to the square of the reciprocal of the distance, so it becomes substantially 1/4 or more, making measurement difficult.

[Invention or problem to be solved] The technical problem of the invention is to eliminate the decrease in light intensity due to increase in L focal length/Jn in an ocular function measuring device, and to make the minimum pupil diameter sufficiently small. The objective is to obtain an optical system with a minimum pupil diameter reduction.

[Means for Solving the Problems] The minimum permissible dragon hole diameter reduction optical system of the present invention for solving the seventh problem is a light projecting system that goes into an ocular function measuring device that measures refraction and accommodation of the eye, and an optical system for reducing the diameter of the eye. This is an optical system to be additionally provided between the existing ocular function measurement equipment that measures the refraction and accommodation of the eye, and consists of an optical system that creates an enlarged image of the eye while preserving its optical properties. By adding an optical system that creates an enlarged image of the eye while preserving its optical properties, it becomes possible to eliminate the decrease in photosensitivity due to an increase in focal length and to make the minimum pupil diameter sufficiently small.

[Embodiment] Next, with reference to FIGS. 1 to 3, an actual example of a system in which the diameter of the hole A' is reduced by a minimum of 1 according to the present invention will be described.

The first reason is that in ocular function measuring instruments that combine multiple light elements to measure refraction and accommodation of the eye, such as the known O-1 helifractometer and three-dimensional optometer. The main part of the optical system used is an optical system that creates a magnified image of the eye while preserving its optical properties.In other words, it preserves the property of converting parallel light into parallel light and increases the magnification in the direction perpendicular to the axis. It consists of an optical system with a constant shift.

To explain this in detail with reference to FIG. 1, when the arrangement is as shown in FIG. 1, the light emitted from point B is focused on point D, and the light parallel to point B becomes ten-line light at point D. Therefore, in this optical system, optical elements corresponding to those in FIG. 5 are given the same reference numerals.

The minimum permissible pupil diameter reduction optical system of the present invention reduces the minimum permissible pupil diameter by additionally installing it between the light projection system and the eye in an ocular function measuring device such as a trifractometer. If you place a glass that allows it to move, an image that is twice the size of your eye will be created at point B by the optical relay system.

Now, in FIG. 1, from focal position A of lens L2 to X
Assuming that the eye is focused on the index T placed at a position that has been moved by a certain distance, based on Gauss's formula, the image distance lllIb2 is given by the lens L2, so from point B, the position is f''/x. There appears to be an index T.Next, when lenses 1 and 3 act on that image, the image I#
m b. becomes.

Furthermore, depending on lenses 1 and 4, the image distance #b4 has been explained assuming that the diameter is 172, or generally I/n
Needless to say, if you do this, you just need to multiply the obtained Shibuta by 02.

Mata, present invention 1't Raha, JP-A-62-87:10 (
4l+-Gan Sho 60-146227), the eyeball no a1 made the fA node measurable even when the eyes were moved freely.
Orikigumi [proposes a fixed kesa].

1. It looks like there is a T.

When measuring with a refractometer, it is customary to define thiobuta (D), which is the reciprocal of the specific separation (m), so the measured value obtained by adding such an optical relay system is By simply multiplying by 4, the minimum pupil diameter can be halved, and the refraction and accommodation values can be easily measured. In addition, in the above embodiment, a pair of concave mirrors and a second mirror are placed opposite each other to form an image on the reflective surface of the minimum pupil. By tilting the two-axis swinging mirror based on the output of the direction measuring section, the second real image is formed as a real image, regardless of changes in the direction of the eyeball. This device is equipped with a 9th 9 10 ra swing drive mechanism, and a refractive power measurement unit that receives reflected light from the fundus of the eye and measures the refractive power of the eyeball based on positional deviation. The optical relay system shown in Figure 2 is based on the idea of relaying the image of the eye at the same magnification.

However, by applying the principles of the present invention and using a lens system as shown in Figure 3, it is possible to double the image of the eye without impairing the optical properties, as described above. , the minimum pupil diameter is 1. /2 can be constructed. In this case as well, setting the magnification to n is easy as in the above case.

[Effects of the Invention] As is clear from the detailed description in L below, according to the present invention, the existing ocular function measurement device for measuring refraction and accommodation of the eye can be used to expand the eye while preserving the optical properties. By simply adding an optical system to create an image, the minimum pupil diameter can be made sufficiently small without causing a decrease in light intensity as would be the case when doubling the focal length.
The functions of the eyes of young people and middle-aged people i! It will also be possible to use it for mausoleum purposes.

[Brief explanation of drawings]

Fig. 1 is a configuration example showing the essential parts of the optical system of the present invention which is additionally used in a known ocular function measuring device, and Fig. 2 is an optical relay system in an ocular refractive power measuring device previously proposed by the present invention. Figure t53 is an explanatory diagram of an optical relay system to which the principle of the present invention is applied. Figure 4 is a configuration diagram of the optical system of an existing autorefractometer.
FIG. 6 is a diagram illustrating the basic configuration of the light projection system, and FIG. 6 is an explanatory diagram of an LED image of a corneal specialist. 11 l 2

Claims (1)

[Claims] 1. An optical system that is additionally installed between the light projection system and the eye in an ocular function measuring device that measures refraction and accommodation of the eye, and that creates an enlarged image of the eye while preserving its optical properties. What is claimed is: 1. An optical system for reducing the minimum allowable pupil diameter for an ocular function measuring instrument, characterized in that the minimum allowable pupil diameter can be reduced.