JPH0337929B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides positioning for aligning the optical axes of the left and right ophthalmological devices with the optical axes of the corresponding eyes to be examined, and for keeping the working distance from the eyes to be constant to the ophthalmological devices. Regarding equipment.

Most conventional ophthalmic devices are for one eye, and there are almost no examples of devices for binocular use. In particular, no alignment device for binocular use with a simple structure for accurately aligning an ophthalmological device with respect to the eye to be examined has been found.

An object of the present invention is to provide a positioning device with a simple configuration for accurately positioning left and right ophthalmological devices with respect to the eye to be examined.

The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 is a side view of the embodiment of the present invention when it is attached to an ophthalmoscope, and FIG. 2 shows the main parts of the embodiment of the present invention in the direction of arrow A-A in FIG. FIG. 3 is an example of the second mark, and FIG. 4 is an image of the completed positioning observed by the observation device.

In FIG. 1, a half mirror 1 is installed obliquely in front of the eye E to be examined so as to reflect the light from the eye E downward, and an objective lens 2 is provided in the reflected optical path. . This first objective lens 2
is also used as an objective lens of an ophthalmoscope B, which will be described later as an example to which this embodiment is applied. A half mirror 3 is provided behind the objective lens 2, and a pinhole 4 and a light source 5 for illuminating the pinhole 4 from behind are provided in its reflection optical path. The position of the pinhole 4 is determined so that it is conjugate with the corneal surface of the eye E to be examined with respect to the objective lens 2 when the eye ophthalmoscope B, which will be described later, is in a position where the eye E to be examined can be measured. half mirror 1
An observation optical path is formed between the objective lens 2 and the objective lens 2, and an optical path changing prism 6 is provided in the observation optical path to bend the optical path downward. ing. Behind the optical path changing prism 6 is an objective lens 7 whose front focal point coincides with the conjugate position of the pinhole 4 formed by the objective lens 2, and behind it is a half prism 8. The half prism 8 has a dividing surface that divides the optical axis of the objective lens 7 into a lower part in the plane of the paper and a lower part in the direction perpendicular to the plane of the paper. 7 is reflected and bent to the right, and the optical axis of objective lens 11 is transmitted to the right, thereby making the optical axes of objective lenses 6 and 11 substantially coincident).

As shown in FIG. 2, the light from the light source 9 also enters the half prism 8, and the half prism 8
By transmitting the light, it matches the light from the objective lens 7. Between the light source 9 and the half prism 8, a mark plate 10 and a mark plate 1 are provided, each having cross marks intersecting on the optical axis from the light source 9 side as shown in FIG.
An objective lens 11 whose front focal position coincides with the front focal position is provided above the lens 0. The light from half prism 8 is
The light enters the optical path changing prism 13 of the observation device 12. As can be seen from FIG. 2, the positioning devices are provided corresponding to the left and right ophthalmological devices B and B' (FIG. 1 shows only one of them). The left and right position detection devices A, A' are integrally fixed to the ophthalmological apparatuses B, B' so as to be substantially symmetrical. Therefore, a description of the position detecting device A' will be omitted by attaching a prime to the member corresponding to the device A.
Due to the symmetrical arrangement as described above, the light from the half prism 8 of one position detection device A and the light from the half prism 8 of the other position detection device are configured to match, and the light from the half prism 8 of the other position detection device A is configured to match. At this position, a switching prism consisting of a pair of prisms 13 and 13' that move up and down in the direction perpendicular to the plane of the drawing in FIG. 2 is arranged. The light reflected by the prism 13 or 13' enters the imaging lens 14. Imaging lens 1
The image generated on the rear focal plane F of 4 is observed with an eyepiece (not shown), an image pickup tube, or the like. On this occasion,
The positions of the pinhole 4 and the mark plate 10 in the direction perpendicular to the optical axis are adjusted using a simulated eye or the like so that the intersection point of the bright spot and the cross mark coincide. If an image pickup tube is used, the light sources 5 and 9 can be configured to emit infrared rays. The observation system 12 may be fixed to either one of the position detectors A, A', or may be fixed to the main body of the apparatus (not shown). In this example, the explanation will be made assuming that it is fixed to device A.

On the other hand, as shown in FIG. 1, the subjective ophthalmoscopy device B as an ophthalmological device includes a first imaging lens 2, a reflecting mirror 3, an image rotation prism 20, and a mirror 3, which are arranged symmetrically with respect to the optical axis. A first aperture 21 having a pair of apertures 21a and 21b, a reflecting mirror 22, a second imaging lens 23, a focusing prism 24,
a second diaphragm 25 formed with a pseudo-rectangular aperture 25a with a protruding center portion; a condenser lens 26;
Light sources 27 are sequentially provided. . The focusing prism 24 is provided so as to be movable in the direction of the optical axis (indicated by an arrow in FIG. 1), and by moving the focusing prism 24, the first aperture 21
The position of the second diaphragm 25 relative to the optical axis can be changed, thereby measuring the power, and the rotation of the image rotating prism 20 can similarly rotate the first diaphragm 21 around the optical axis. effect and thereby measure the astigmatic axis.

Because of this configuration, the measurer first inserts the prism 13 into the optical path, asks the subject to look forward through the half mirror 1, and while observing the image plane F, The device is three-dimensionally mounted on a subject who is fixed on a fixing base (not shown) so that the intersection point of the bright spot and the cross mark formed by the mark plate 10 coincides with the center of the subject's eye E as shown in FIG. Move to. (A well-known mechanism can be used.) When an image as shown in FIG. 4 is observed, the alignment is completed. At this time, the aperture 21 of the subjective ophthalmoscope B is set to be conjugate with the corneal surface of the eye E to be examined by the objective lens 2. As a result, the subjective ophthalmoscope B is placed in a measurable position. Next, instead of prism 13, prism 1
3' into the optical path and perform the same operation as described above, the other eye to be examined B can be aligned. At this time as well, although not shown, the diaphragm having two apertures of the other eye B' becomes conjugate with the corneal surface of the eye E'.

In such a state, for example, as shown in FIG.
The aperture 25a is separated into two parts, and images shifted in the diagonal direction are observed at the same time (the shaded part is bright).

In this case, the direction of the astigmatic axis of the eye E to be examined does not match the direction of the apertures 21a, 21b of the diaphragm 21, that is, the most common state.

Therefore, first, the image rotation prism 20 is rotated, and the 2
The two images are not twisted as shown in Figure 5a,
That is, the two images are brought into a state in which the directions of the two images coincide with each other for the subject as shown in FIG. 5b. The rotation angle of the image rotation prism 20 at this time corresponds to the direction of the astigmatic principal axis of the eye E to be examined.

Next, as shown in FIG. 5c, the focusing prism 24 is moved until the two images coincide with each other for the subject. Focusing prism 24 at this time
The amount of movement corresponds to the refractive power of the eye E in the direction of the astigmatic principal meridian.

Therefore, by the above-described operation, it is possible to know the direction of one astigmatic principal meridian in the astigmatic eye E and the eye refractive power in this direction.

Next, the image rotating prism 20 is further rotated by 90 degrees, and the focusing prism 24 is activated until the subject responds that the two images match.
Depending on the position of the focusing prism 24 at that time, the eye refractive power in the direction of the other principal axis of astigmatism can be determined.

That is, if the direction of the aperture of the diaphragm 21 matches the direction of one of the astigmatism principal meridians of the eye B, the patient can observe an image as shown in FIG. By simply moving the shing prism 24, it is possible to see a matching image as shown in FIG. 5c.

If the eye E to be examined is not an astigmatic eye, the image of the diaphragm will not be observed twisted as shown in Figure 5a, and therefore it will always be observed from a distance corresponding to its dioptric power, as shown in Figure 5d. become.

Note that if the light source 5 is turned off when the alignment is completed, the subject can see the opening 25a of the second diaphragm 25.
Only the image of the image can be observed.

As described above, according to the positioning device of the present invention, when the left and right position detecting devices move independently, the light emitted from the left and right position detecting devices is aligned in the same straight line due to the mechanical guidance error. If you don't ride the
In addition, when switching the switching prism, there is some wobbling in the vertical movement guidance and rotational movement guidance, so even if the prism rotates slightly, the parallel system between the position detection devices A, A' and the observation system 12 cannot be adjusted. In addition, since the alignment index (the cross mark on the mark plate 10 in the embodiment) is provided, the projection mark (pinhole 4 in the embodiment) generated on the image plane F and the alignment index are formed within the screen. The position of changes, but
Since the positional relationship between the two does not change (however, the light from the eye to be examined is affected by one reflection from the half prism 8, and the light from the mark plate 10 is affected by the tilt of the device almost twice as much), For example, lens 1
It is necessary to make corrections such as making the focal length of lens 1 twice the focal length of lens 7), and if the device is moved so that the position of the eye to be examined is at a predetermined position (in the example, the center of the cornea) based on both of them. Therefore, it is possible to obtain a positioning device with a simple structure that can perform positioning with high precision without being affected by backlash of mechanical guide surfaces.

[Brief explanation of the drawing]

Fig. 1 is a side view of the embodiment of the present invention when it is attached to a subjective ophthalmoscope, Fig. 2 is a view taken along arrow A-A in Fig. The figure shows the cross mark on the mark plate, FIG. 4 is an illustration of the image observed by the observation device when alignment is completed, and FIG. 5 is an explanatory diagram of the image observed by the subject. [Explanation of symbols of main parts], 2...First objective lens, 7,7'...Second objective lens, 11,1
1'... Third objective lens, 8, 8'... Optical member,
A, A'... Optical device, 14... Objective lens for imaging, 12... Observation device, F... Focal plane of the objective lens for imaging.

Claims (1)

[Claims] 1 In a device for aligning each ophthalmological device with the corresponding eyes E and E′ by moving the left and right ophthalmological devices B and B′ independently, the first mark 4 and the a first objective lens 2 that projects the first mark 4; and a first objective lens 2 that projects the first mark 4.
a second objective lens 7 whose front focal position is substantially aligned with a position conjugate with the first mark 4, and which converts the light beam from the first mark 4 obtained from the conjugate position into a parallel light beam; 10 and
a third objective lens 11 disposed such that its front focal position substantially coincides with the second mark, and which converts the light beam from the second mark 10 into a parallel light beam;
It is located behind the objective lens 7 and the third objective lens 11, and is located in the parallel light flux of each lens 7, 11, so that the optical axis of each lens almost coincides with the parallel light beam of each lens 7, 11. An optical device including an optical member 8 that emits a luminous flux is symmetrically provided integrally with the ophthalmologic apparatus, and A, A',
An observation device 1 having an imaging objective lens 14 into which parallel light beams from the left and right optical members 8, 8' are incident.
2, and the left and right ophthalmological apparatus B,
A positioning device characterized by positioning B′ respectively.