JPS6152850A - Eyeball refraction force measuring 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] Industrial applications The present invention is an apparatus for measuring the refractive power of an eyeball.

Conventional technology A known measuring device used to circumoptically measure the refractive power of an eyeball emits infrared light converged into a beam in a pulsed manner at a high frequency, irradiates the eyeball, and creates a net. The image created by using the light spot obtained on the film 1 as a secondary light source is applied to the photodetector 1, and the difference in position on the photodetector is
Then, the refractive power is calculated.

However, with such a measuring device, it is necessary to irradiate the infrared light from the front of the eyeball so that the reciprocating infrared light is not blocked by the erythema. Furthermore, when taking measurements using the above-mentioned device ζmi, it is necessary to fix the eyeballs, so measurements must be taken while looking through a thin peephole.
Measurements under such conditions create a strong mental pressure on the subject, and the subject is more likely to become temporarily nearsighted due to actions such as looking into something, so-called mechanical myopia.
It is not possible to take correct measurements under natural conditions.

Problems to be Solved by the Invention The technical problem to be solved by the present invention is to create an optical system that eliminates the need for the above-mentioned unnatural movements such as looking into the eyes, and that allows correct measurement even when the eyeballs are moved. An object of the present invention is to provide a portable eyeball refractive power measuring device.

Means for Solving the Problems In order to solve the above technical problems, the present invention
M, "j's, The refractive power measurement device modulates infrared light focused in a beam shape with a high frequency and emits it in a pulse shape.
(2) A light emitting/receiving measuring device that receives reflected light from the fundus of the subject's eye and measures the refractive power of the eyeball, and a drive unit that applies slight rotation in two axes to the reflective surface that reflects the infrared light. A bifocal interfocal beam comprising a plane reflecting mirror to obtain and an elliptical mirror having one focal point located at the center of rotation on the plane reflecting mirror and reflecting the reflected light from the reflecting mirror and focusing it on the other focal point. an infrared light reflector that reflects the infrared light from the bifocal focusing device and focuses it onto the subject's eyeballs but transmits visible light; It is configured by including an eye movement detection device that provides feedback so that the drive unit always irradiates infrared light from the front of the eyeball.

Function: In the real-time eyeball refractive power measuring device of the present invention having the above-mentioned configuration, the beam S beam infrared light from the light emitting/receiving measuring device is directed to a plane reflecting mirror rotatable on two axes at an angle of -1°. = j'r'y'ii After being reflected, it is reflected to the elliptical mirror of the bifocal focusing device] (iJ3 It9 [but it is reflected by the ellipse' at the center of rotation of the plane reflecting mirror], and the effect is 6 one focal point. Because of this, the light beam reflected by the elliptical mirror is always focused on the other focal point of the bifocal focusing device, and the light beam focused at this focus is reflected by the infrared light reflector. The center of the eyeball is set at the position of point Jlj after reflection, and the movement of the eyeball is tracked by an eyeball movement detection device, and this signal is fed back to the two-axis swing mechanism of the flat reflector to determine the orientation of the flat reflector. By controlling according to the movement of the eyeballs,
It is possible to irradiate a light beam from the front of the eyeball regardless of the movement of the eyeball.

Furthermore, since the infrared light reflector reflects only infrared light and transmits visible light, the subject can perform measurements while looking at the work environment etc. through the reflector in a natural state.

Effects According to the eyeball refractive power measuring device of the present invention, it is not only possible to perform accurate measurements while the subject is looking at the work environment in a natural state, but also allows the test subject to perform 5 vertical eye movements during the measurement. The irradiation direction of the light beam can be adjusted according to the movement of the eyeball, so that the eyeball can always be irradiated with the light beam from the front.

~Example-Examples Examples of the present invention will be described in detail below with reference to the drawings.

In Fig. 1, reference numeral 1 denotes an infrared light projection/reception measurement device that modulates infrared light with high frequency, converges it into a beam, and emits it, and also receives reflected light from a light spot on the fundus of the eye and determines its position. It has a function of detecting the refractive power of the eyeball and measuring the refractive power of the eyeball by calculation in the data processing section. The plane reflecting mirror 2 disposed opposite to the above-mentioned light emitting/receiving measuring device 1 is supported by a flexible support plate 3 so as to be able to rotate slightly on two axes around the central portion 2a of the reflecting mirror 2, and has a two-axis swinging mechanism. Rotational motion is applied in two axial directions by the swinging arm 4, and the reflected light from the plane reflector 2 is scanned at a high frequency by the two-axis swinging mechanism 4, and the scanning range is successively changed. and is projected onto the elliptical mirror 5a of the bifocal focusing device 5.

The bifocal focusing device 5 includes elliptical mirrors 5a and 5b,
j One focal point of the elliptical mirror 5a is located at the external rotation center 2a through the plane reflecting mirror 2, and the other focal point is imaged at a common focal point 6 with the other elliptical mirror 5b, and the other focal point of the elliptical mirror 5b is The focal point 7 is focused on one point in space, and this focal point 7 is focused on its mirror image position by means of an infrared light reflecting plate 8, so that the focal point 7 is substantially focused on the eyeball 9a of the subject 9. I try to position it at the center of the The bifocal focusing optical device 5 may use a single elliptical mirror, but in that case, the size of the real image focused on other focal points changes depending on the irradiation direction of the light beam, so it is necessary to cancel this. To,
It is effective to provide elliptical mirrors 5a and 5b having the same optical characteristics at symmetrical positions to form a real image with the same magnification. The infrared light reflecting plate 8 reflects infrared light but transmits visible light.

As the eyeball movement detection device 10 that detects the eyeball movement of the subject 9, a known detection device that detects the eyeball movement based on the position of reflected light on the cornea of infrared light projected onto the eyeball, for example, can be used. This eye movement detection device 1
The output of 0 is output to the two-axis swinging mechanism 4, which is a single-lumen drive unit of the flat reflecting mirror, and the flat reflecting mirror 2 is given a rotational movement corresponding to the movement of the eyeball.

In addition, since it is necessary to set the center of the eyeball to be on one focal point of the elliptical mirror 5b, as shown in the figure, means for monitoring this is provided in the above-mentioned 111% ball movement detection device 10.
It is effective to attach it to

The eye movement detector f2Llo shown in the figure is designed to also function as a monitor TV, so when making settings while monitoring, it is better to monitor while aligning the optical axis with the standard direction of the measurement beam. Since it is easy, a half mirror 11 is provided to align the optical axes. In addition, the eye movement detection device 10 functions as a monitor TV and at the same time has a function of detecting 1 ball movement (x, y
) The system is configured so that the coordinates can be measured in real time, and therefore the two-axis oscillating mechanism 4 is driven by this output, and the measurement beam is controlled so as to always point toward the visual field. As the point of high brightness, for example, the infrared light emitting source 12 is the eyeball angle pl! A--
Below I-, a virtual image created by reflection on a wavefront can be used.
The eye movement detection device 10 is reflected by the corneal surface: +d
Since the position of the virtual image changes with eye movement, this is used for movement detection. In addition, in order to distinguish the virtual image of the infrared light emitting source from the virtual image created by the infrared destination for use, it is sufficient to perform time-division blinking and detect a point synchronized with it. - In the figure, 13 is the infrared light source. A subject's work ring 11, such as an information input/output device, is shown as seen through the light reflector 8.

In the eyeball refractive power measuring device having the above configuration, first, a beam-shaped infrared light modulated with a high frequency is projected from the light emitting/receiving measuring device 1 onto the eyeball 9a of the subject 9. The light is once reflected by the mirror 2, and the reflected light is further reflected by the elliptical mirror 5a of the bifocal focusing device 5. At this time, since one focal point of the elliptical mirror 5a is located at the rotation center 2a of the plane reflecting mirror 2, this rotation center 2a
When a light beam is irradiated onto the elliptical mirror 5a, the light beam reflected by the elliptical mirror 5a always converges on the other focal point, that is, the common focal point 6 with the elliptical mirror 5b. Moreover, in the elliptical mirror 5b,
The light beam from the upper common focal point 6 is focused on the other focal point 7:j
be illuminated. Therefore, before the light beam converges on this focal point 7, it is reflected again by an infrared light reflector 8 that reflects only infrared light, and by setting the focal position ζ after reflection and the center of the eyeball 9a, the light beam is always irradiated into the eyeball.

In other words, even if the angle of the two-axis rotatable plane reflector 20 that reflects the light beam is changed, the light beam will follow other reflection paths in the bifocal focusing device and will ultimately converge at the same focal position. In this way, the bifocal focusing device 5
By utilizing the property that light emitted from one focal point of an elliptical mirror always forms an image on the other focal point, it is possible to set up a structure that irradiates the same point from various directions, and the eyeball is placed at this focal point. By placing the center of the eyeball, even if the direction of the eyeball changes due to the subject's eyeball movement, the infrared light beam will always be emitted from the front of the eyeball by simply rotating the two-axis rotatable plane reflector 2 slightly. It becomes possible to do so.

Therefore, the movement of the n[+ball is t
Eye movement detection device! 0 and feeds back this signal No. 7 ijj to the two-axis swing mechanism 4 of the plane reflector 2, the direction of the plane reflector corresponds to the movement of the eyeball and the light beam is irradiated from the front of the eyeball. This allows accurate measurements to be taken at all times regardless of eye movement.

In addition, the infrared light reflector 8 that reflects the light beam just before it enters the eyeball reflects only the infrared light and transmits visible light, so the subject can view the work environment 13 and the subject as appropriate through this reflector 8. You can maintain a natural state even while working.
Moreover, measurements can be performed in real time.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an eyeball refractive power measuring device according to the present invention. 1...Light emitting/receiving measuring device, 2...Plane reflecting mirror, 2a...
Center of rotation, 5... Bifocal focusing device, 5a, 5b...
Elliptical mirror, 6.7--focal point, 8...infrared reflector,
9... Subject, 9a... Eyeball, lO... Eye movement detection device. Designated agent: Agency of Industrial Science and Technology Product Science Research Institute

Claims (1)

[Claims] 1. A light emitting/receiving measuring device that modulates infrared light converged in a beam shape with a high frequency and emits it in a pulse shape, and measures the eyeball refractive power by receiving reflected light from the fundus of the subject's eye; A plane reflector that can give a slight rotation in two axial directions to a reflecting surface that reflects light by a drive unit, and one focal point located at the center of rotation on the plane reflector, and the reflected light from the reflector is A bifocal focusing device equipped with an elliptical mirror that reflects the light and focuses it on the other focal point, and a bifocal focusing device that reflects infrared light from the bifocal focusing device and focuses it on the subject's eyeball, but visible light does not. It is characterized by comprising an infrared light reflecting mirror that transmits the infrared light, and an eye movement detection device that captures the movement of the eyeball and feeds back the infrared light so that the drive unit of the plane reflector always irradiates the infrared light from the front of the eyeball. An eye refractive power measurement device.