JPS6234529A - Slit projection 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 [Field of Industrial Application] The present invention relates to a slit projection device having a tilting mechanism for a slit projected image.

[Prior art] Using a slit lamp, which takes advantage of the fact that the eyeball is not a completely transparent body and the incident light is scattered, albeit slightly,
Slit lamp examination, in which a slit image is projected onto the eyeball and the optically sectioned image is observed under magnification, is widely used in ophthalmological treatment and when observing the fundus of the eye and the chamber angle when wearing contact lenses. At this time, if the specularly reflected light from the cornea, crystalline lens, or contact lens surface is not removed, observation will be hindered, so it may be necessary to make the slit image horizontal. In addition, when this horizontal slit image is formed on the subject's eye, by changing the irradiation angle vertically and horizontally, slit-cut images of the subject's eye can be obtained from various angles, and the entire eye examination can be performed. You can know the status. Adjustment of the irradiation angle by so-called banning, in which the horizontal slit image is moved above the water, can be performed relatively easily, but adjustment of the irradiation angle by so-called tilting, in which the horizontal slit image is moved in the vertical direction, is performed by a complicated mechanism.

FIG. 3 is a block diagram of a conventional slit projector having a typical vertical projection angle adjustment mechanism.

In FIG. 3, light emitted from a light source 1 passes through a condenser lens 2, and is turned into a slit image directed in a predetermined direction, that is, in the horizontal direction, by the rotation of a slit 3 and an image rotor beam 4. The direction is changed by the reflecting mirror 6 via the mirror 6, and a horizontal slit image is formed at a predetermined position near the eye E to be examined. In this projection optical system, in order to change the irradiation angle of the slit image by θ from the horizontal direction in the vertical direction, the first reflecting mirror 6 is lowered from the solid line position to the dotted line position, and is also tilted at an angle α with respect to the horizontal direction. In order to set the reflection fi6 provided at an angle α+θ/2 and further correct the optical path difference, the projection lens 5 must also be lowered from the solid line position to the dotted line position'. A mechanism having such a large-scale movable part has the disadvantage that the device becomes large and expensive, and furthermore, it requires time for switching.

[Object of the Invention] An object of the present invention is to provide a slit that allows a slit image to be easily irradiated onto the subject's eye at a predetermined angle from the vertical direction without performing complicated movements of optical members as described above. The purpose of the present invention is to provide a projection device.

[Summary of the invention] The gist of the present invention to achieve the above objects is as follows.

An apparatus comprising: a projection optical system that projects light from an illumination light source onto a subject's eye as a slit image via a slit; and an observation optical system that magnifies and observes the slit image.
The projection optical system has two optical paths that share some optical members, project a slit image onto the subject's eye in a substantially horizontal direction and at a predetermined elevation angle, and maintain an imaging relationship, respectively. This is a slit projection device characterized in that an optical path can be arbitrarily selected by an optical path selection member.

Embodiments of the Invention] The present invention will be described in detail based on embodiments illustrated in FIGS. 1 and 2.

In FIG. 1, reference numeral 11 indicates a light source using a halogen lamp or the like, and the optical axis 0 of this light source 11 is located on the optical axis 0 of the light source 11.

Sequentially condenser lens 12. A slit 13, an image rotator rhythm 14 for rotating the slit image, a projection lens 15. Polarizing plate 16. A polarizing prism 17 and a reflecting prism 18 are arranged.

A binocular stereoscopic microscope 19 for magnifying and observing the projected image is disposed at an extension J- connecting the eye E to be examined at the projection position and the reflecting prism 18. Note that a panning mechanism that adjusts the focal position of the stereoscopic microscope 19 and rotates the projection optical system and the stereoscopic microscope 19 in a horizontal plane around the eye E to be examined is not shown.

Here, the light beam emitted from the light source 11 illuminates a slit 13 with a condenser lens 12, further passes through an image rotor prism 14, passes through a projection lens 15, and is directed to a polarizing plate 16 and a polarizing prism 17, either straight or diagonally. If the light travels in a straight direction, it is further reflected by the reflecting prism 18 to form a slit image on the subject's eye E from the horizontal direction.

When projecting a slit image onto the subject's eye E from the horizontal direction, the light flux is polarized in a direction perpendicular to the plane of the paper by a polarizing plate 16, and is caused to advance straight through a polarizing prism 17 and reflected by a reflecting prism 18 located at each image formation position. Thereby, the eye E to be examined can be irradiated with the slit image from the horizontal direction. At this time, the reflection prism 18 is
It is necessary to select the size of the glass and the glass material.

In addition, when forming a slit image on the subject's eye E) with an elevation angle, by rotating the polarizing plate 16 by 90'' around the optical axis 0, the light source image is set at a predetermined elevation angle by the polarizing prism 17. It is reflected by holding the eye E and can be radiated unidirectionally.

FIG. 2 shows another embodiment, in which the same reference numerals as in FIG. 1 indicate the same members. 20 is a half prism having an amplitude division ratio of 1:1, and 21a and 21b are mechanical shutters or liquid crystal shutters respectively disposed on the two exit surfaces of the half prism 20.

In this case as well, the light beam passing through the half prism 20 is divided into two parts, and by blocking one optical path and selectively selecting the optical path using mechanical shutters 21a and 21b, the light beam can be divided horizontally or at a predetermined angle. A slit image can be projected onto the eye E by holding the eye.

[Effects of the Invention] As explained above, the slit projection device according to the present invention has the following effects:
The angle in the elevation direction of the slit image can be changed by rotating a polarizing plate or by using an extremely simple mechanism that simply opens and closes a shutter.

[Brief explanation of the drawing]

Drawings 1 and 2 show an embodiment of the slit projection device according to the present invention, FIG. 1 is a side view, FIG. 2 is a side view of another embodiment, and FIG. 3 is a conventional slit projection device. It is a side view of the cedar device. 11 is a light source, 12 is a condenser lens, 13 is a slit, 14 is an image rotator prism, 15 is a projection lens, 16 is a polarizing plate, 17 is a polarizing prism, 18 is a reflecting prism, 19 is a stereo microscope, 20 is a half The prisms 21a and 21b are shutters.

Claims (1)

[Scope of Claims] 1. An apparatus comprising a projection optical system that projects light from an illumination light source onto a subject's eye as a slit image through a slit, and an observation optical system that magnifies and observes the slit image. The projection optical system has two optical paths that share some optical members, project a slit image onto the subject's eye in a substantially horizontal direction and at a predetermined elevation angle, and maintain an imaging relationship. A slit projection device characterized in that these optical paths can be selected by an optical path selection member. 2. The slit projection device according to claim 1, wherein the optical path selection member is a combination of a polarizing prism and a polarizing means. 3. The slit projection device according to claim 1, wherein the optical path selection member is a light blocking member that can be opened and closed. 4. The slit projection device according to claim 3, wherein the openable and closable light blocking member is a mechanical or liquid crystal shutter.