JPS61244324A - Position regulator of ophthalmic machine - 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 Field of Industrial Application This invention relates to a position adjustment device for aligning the optical axis and working distance of an ophthalmological instrument such as a refractometer or a fundus camera.

PRIOR ART Conventional devices of this type include, for example, an observation optical system for observing the anterior segment of the eye. ) is also constructed so that the position can be adjusted for optical axis alignment and working distance alignment.

In addition, there is another device in which the above-mentioned observation optical system is formed at a high magnification and is configured to observe the target image.6 Problems with the Prior Art However, in the above-mentioned first device, Although the anterior segment image can be observed and the optical axis alignment adjustment is easy, the imaging magnification of the index image is small, which means that the sensitivity for adjusting the working distance is low, and the operability is poor. Met.

In addition, although the second device described above is capable of highly sensitive working distance adjustment, it is not able to detect the entire anterior segment image, so it has a drawback in terms of operability in optical axis alignment adjustment. Furthermore, since the field of view for observation is narrowed, it is extremely difficult to determine whether the object to be observed, that is, the object to be examined is left or right.

Means for Solving the Problems This invention provides a first observation optical system for observing the anterior segment of the subject's eye, as well as a second observation optical system having a higher magnification than this observation optical system.
I! A sensing optical system is provided, and the working distance detection target image projected onto the subject's eye is observed through this second a-side optical system with high magnification.

The anterior segment of the eye to be examined is observed by a first optical system with low magnification, and the index image reflected on the anterior segment of the eye to be examined is observed by a second observation optical system with high magnification. Adjust the optical axis using the observation optical system.

The working distance can be adjusted by observing the target image using the second observation optical system.

Embodiment FIG. 1 shows a case where the present invention is applied to a refractometer, in which an objective lens 3 is arranged on the optical axis 2 of the cornea 1A of the eye 1 to be examined, and behind this objective lens 3. A diaphragm plate 4 is arranged. Further, behind the diaphragm plate 4, a pair of convex lenses 6.degree. 7 are arranged, respectively, located on both sides of the optical axis 2 with the optical axis 2 in between. Concave lenses 8 and 9 are arranged behind each convex lens 6.7, and the convex lens 6 and concave lens 8 and the convex lens 7 and concave lens 9 constitute two Galileo variable power systems, respectively. Further, a half mirror 10 is arranged on the optical axis 2, and an imaging lens 1 is placed behind the half mirror 10.
1 and an image pickup tube 12 are arranged, and an image is displayed on a television monitor (not shown) by signals from the image pickup tube 12.

On the other hand, a projection lens 13 is disposed in front of the half mirror 10 in a direction orthogonal to the optical axis 2, and a light source 15 is disposed in front of the second projection lens 13 via a reference scale 14, and is used for imaging. An image of a reference scale 14 is projected onto the tube 12.

On the other hand, index plates 16.17 for working distance detection are arranged on both sides of the optical axis 2 in front of the eye 1 to be examined, and light sources 18.1 are respectively arranged behind each index plate 16.17.
9 is placed.

As shown in FIG. 2, the aperture plate 4 has a vertically elongated through hole 4a in its center, and small circular holes 4b on both sides of this through hole 4a.
, 4c, and as shown in FIG. 3, the reference scale 14 includes an optical axis indicator 14a having four short lines arranged around the outer periphery of a small circle, and a position indicator 14b consisting of short lines on both sides of this indicator. .

14c, and as shown in FIG.
7a, respectively.

It should be noted that the magnification of the second AM optical system constituted by the Galileo variable magnification system is set higher than that of the first I optical system constituted by the objective lens 3, the imaging lens 11, etc.

Moreover, a half mirror 20 is arranged between the objective lens 3 and the eye 1 to be examined, and the half mirror 20 and the mirror 2
1, an objective lens 22 of a refractometer and a known refractometer measurement optical system 23 are arranged.

With these configurations, the reflected light beam from the anterior segment of the eye to be examined is made into a parallel light beam by the objective lens 3, and after passing through the through hole 4a, the image of the anterior eye segment of the eye to be examined is formed on the imaging tube 12 by the imaging lens 11. Form. As mentioned above, the image of the reference scale 14 is projected onto the image pickup tube 12, and the images of the reference scale and the anterior segment of the subject's eye are superimposed on the image pickup tube 12. .

The light flux from the working distance index 16a is reflected by the cornea of the subject's eye to form a virtual index image, and after passing through the objective lens 3, the light flux from the index image passes through the small circular hole 4b of the diaphragm plate 4,
The beam is split into two beams by 4c.

This divided light flux passes through two optical paths consisting of a convex lens 6, a concave lens 8, and a convex lens 7, a concave lens 9, and then passes through the image pickup tube 12.
A working distance index image is formed on each. This working distance index image is formed as a single superimposed image at the position index 14b image forming position of the reference scale 14 when the eye 1 to be examined is at an appropriate distance from the objective lens 3, and when the working distance is not at an appropriate distance. In this case, the light beam from the position index 17a is configured to pass through two optical paths and form an index image at the image position of the position index 14c on the image pickup tube 12, as described above.

Next, the operation of the optical system configured as described above will be explained. FIG. 5 shows an image observed on a television monitor when optical axis alignment and working distance adjustment have not been completed. In this case, the center of the pupil 1a' image of the eye to be examined 1 is shifted from the center position of the optical axis index image 14a' of the reference scale 14, and the optical axis alignment adjustment is performed by moving the entire apparatus upward. Let's do it. In the second case, the working distance is also not appropriate, and the working distance index images 16a' and 17a' magnified by the Galileo optical system are observed separately.

On the other hand, FIG. 6 shows the observed image on the television monitor at the time when the optical axis alignment adjustment is completed, and the center of the optical axis index image 14a'' of the reference scale 14 and the center of the pupil image 1a'' are aligned. Next, working distance index images 16a'' and 17a', which are separately observed on the television monitor, are position index images 14b'.

The working distance is adjusted by moving the entire device back and forth so that they overlap one another on 14c. Next, FIG. 7 shows the observed image on the television monitor when the optical axis alignment adjustment and working distance adjustment are completed, and shows the center of the hole image 1a' and the center of the optical axis index image 14a'. match, and one working distance index image 16a'.

17b' all match. By adjusting as in step 2, accurate positioning of the entire device with respect to the eye to be examined is completed.

Effects of the Invention As described above, according to the present invention, the magnifications of the W4 optical system for observing the anterior segment of the subject's eye and the observation optical system for observing the index image reflected on the cornea of the anterior segment of the eye are different. With this configuration, the object to be observed can be easily distinguished, the operability of adjusting the optical axis alignment can be improved, and the working distance can be adjusted with high sensitivity.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of an optical system showing an embodiment of the present invention, Fig. 2 is a plan view showing an example of a diaphragm plate, Fig. 3 is a plan view showing an example of a reference scale, and Fig. 4 is an index. A plan view showing an example of the plate, FIG. 5 is a plan view illustrating a TV monitor image when working distance adjustment and optical axis alignment are not adjusted, and FIG. 6 is a TV monitor image when working distance adjustment is not adjusted. FIG. 7 is a plan view illustrating the television monitor image when the position adjustment is completed. 1...Eye to be examined, LA...Cornea of the eye to be examined 14...Reference scale 16.17...Indicator plate Fig. 2 Fig. 3 Fig. 4 Figure 5 Figure 6 Figure 7

Claims (2)

[Claims] (1) an index projection system that projects a working distance detection index image toward the eye to be examined; a first observation optical system that observes the anterior segment of the eye to be examined; and a first observation optical system provided within the first observation optical system; A position adjustment device for an ophthalmological instrument, comprising: a second observation optical system which has a higher magnification than the first observation optical system and which observes the target image projected onto the eye to be examined. (2) The ophthalmological instrument position adjustment device according to claim 1, wherein the second observation optical system has a plurality of optical paths.