JPH10137189A - Optometric apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a photoconductive member while achieving a smaller diameter of a projection means by arranging the projection means for projecting a specified pattern onto corneas of eyes to be inspected to form a pattern out of a plurality of light emitting elements arranged at the peripheral part of a measuring window. SOLUTION: An optometric apparatus 1 built as refracto/keratometer has a case body and a measuring means 10 by which light is projected onto eyes 2 to be inspected to measure a flexural force of the eyes 2 to be inspected from the reflected light, a projection means 20 to project a specified pattern onto the eyes 2 to be inspected, a fixation target means 30 and an observation means 40 are housed into the case body. The measuring means 10 performs a scanning of measuring light irradiated by a light source 11 in two directions by a chopper 13 driven by a motor 14 and the light is deflected by a half mirror 4 to the eyes 2 to be inspected to irradiate the eyes 2 to be inspected. The projection means 20 has a plurality of light emitting diodes arranged on a circular substrate at an equal interval to project a pattern having dot patterns arranged on a ring onto the corners of the eyes 20 to be inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optometry apparatus for measuring an eye to be examined, and more particularly to an optometry apparatus provided with a projection unit for projecting a predetermined pattern onto the eye to be examined.

[0002]

2. Description of the Related Art Heretofore, as an optometry apparatus mainly used by an ophthalmologist or an optician, an automatic corneal curvature measuring apparatus (abbreviated as autokeratometer) for measuring the shape of a cornea of an eye to be examined, a refraction of the eye to be examined, and the like. Objective eye refractometer (abbreviated as auto-refractometer) for measuring force, or refract keratometer with both functions of automatic corneal curvature meter and objective eye refractometer Have been.

Among these, an automatic corneal curvature measuring apparatus and a refract keratometer have four auxiliary point light sources projected on the corneal surface and, in addition to measuring means for measuring the corneal shape based on the positional relationship of the reflected images, as well as auxiliary means. Projection means is provided for roughly observing whether or not the subject's eye has astigmatism or the subject's eye has an irregular corneal shape. This projecting means projects an annular ring image on the cornea, and the examiner visually compares the shape of the reflected image with respect to the ring image and the shape of the ring image, and how the ring image is distorted. By grasping whether or not the light is reflected, it is possible to observe distortion or the like of the corneal shape.

FIG. 7 shows a conventional projection means for projecting an annular ring pattern onto the cornea. In FIG. 7, a conventional projection unit 50 includes a plurality of LEDs on an annular substrate 51.
(Light emitting diode) 52 is arranged, and a light guide member 53 is arranged near the eye to be examined. The light guide member 53 guides the light incident on the large-diameter portion 54 to the small-diameter portion 55 to scatter a point image formed by the LEDs 52 to form an annular ring pattern, and the ring pattern is used as an eye to be examined. The diameter is made small so that the image can be projected. That is, the light emitted from the plurality of LEDs 52 is guided to the subject's eye via the light guide member 53, becomes a small-diameter annular light, and is projected on the subject's eye.

[0005]

However, as shown in FIG. 7, the projection means 50 in the conventional optometry apparatus is
As described above, since the plurality of LEDs 52 and 52 and the light guide member 53 are formed by members having a large size, particularly in the optical axis direction, the entire projection means 50 has a complicated configuration and is costly. there were.

Further, since the conventional projection means 50 projects through the light guide member 53 as described above, the LED 52
Is attenuated by the light guide member 53 and the light guide efficiency deteriorates, and the light from the LED 52 cannot be used effectively. Therefore, in the conventional optometry apparatus, it is necessary to provide an anterior segment illumination light source for illuminating the subject's eye when observing the subject's eye, separately from the projection means 50. Since it is necessary to separately provide the anterior segment illumination light source as described above, the conventional optometry apparatus has a more complicated configuration as a whole and has a high cost, and an improvement is demanded from this point as well. Was.

Further, the conventional projection means 50 shown in FIG. 7 simply projects an unbroken annular ring pattern onto the eye to be inspected. At this time, if the device is arranged at an optimum distance from the subject's eye, a sharp ring pattern can be observed as shown in FIG. If it is too close, a blurred ring pattern is observed as shown in FIG. However, in this case, whether or not the ring pattern is blurred is determined by a quantitative criterion that the wire diameter of the ring pattern is large or small, so it is actually difficult to determine,
Distance adjustment was difficult. In view of the fact that such an alignment difficulty is generally caused by an error in the working distance causing a measurement error, an improvement has been demanded.

The present invention has been made in view of the problems in such conventional optometers, and has a simple configuration and low cost, and can be used also as an anterior segment illumination light source. An object of the present invention is to provide an optometry apparatus provided with a projection unit that can easily adjust the distance.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the conventional optometer, the present invention according to claim 1 has the following features.
Measuring means for measuring the eye to be inspected through a measurement window provided on the outer surface of the apparatus main body; projecting means for projecting a predetermined pattern on the cornea of the eye to be inspected; and observing the pattern projected on the eye to be inspected. In an optometry apparatus including an observation unit, the projection unit is configured to form the pattern from a plurality of light-emitting elements arranged around the measurement window.

According to a second aspect of the present invention, in the first aspect of the present invention, the plurality of light emitting elements are constituted by a plurality of light emitting diode chips arranged on an annular substrate. I have.

According to a third aspect of the present invention, there are provided a plurality of light emitting elements provided around the measurement window, wherein the plurality of light emitting elements form a projection pattern for measuring a corneal shape of an eye to be examined. It is characterized by being formed and illuminating the anterior segment of the eye to be examined.

[0012]

An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view of the apparatus 1, FIG. 2 is a front view of the apparatus 1, and FIG. 3 is a configuration diagram of an optical system of the apparatus 1. As shown in FIG. 1, the present apparatus 1 is configured as a refract keratometer for measuring the eye 2 to be inspected, and projects light onto the eye 2 shown in FIG. A measuring unit 10 for measuring the refractive power of the eye 2 from the reflected light, a projecting unit 20 for projecting a predetermined pattern onto the eye 2, a fixation target unit 30, and an observation unit 40 are housed therein.

As shown in FIG. 2, the housing 3 is provided with a measurement window 4 fitted on the outer peripheral surface on the side of the eye 2 to be examined. The measurement light for is freely transmitted. FIG. 1, FIG.
As shown in FIG. 2, a grip 5 for holding the device 1 is provided.
And a viewfinder 6 are provided.

Next, the measuring means 10, the fixation target system 30, and the observation means 40 inside the housing 3 will be described, and then the projection means 20 will be further described. As shown in FIG. 3, the measuring means 10 includes a light source 11, a lens 12, a chopper 13,
The measuring light emitted from the light source 11 is collected by the lens 12 so that the image of the light source 11 is formed on the pupil of the eye 2 to be examined. Although it is illuminated, it is scanned in two directions by the chopper 13 driven by the motor 14 and further deflected by the half mirror 15 toward the eye 2 to be inspected. Reach. Then, the measurement light reflected by the eye 2 is received by the light receiver 18 via the half mirrors 16 and 15 and the lens 17, and various measurement values are calculated by a calculation unit (not shown).

The fixation target system 30 is, as shown in FIG.
Fixation target 32, light source 31 illuminating fixation target 32, lens 3
3 and a half mirror 34. The fixation target 32 image for fixing the viewpoint of the subject's eye 2 is formed by the lenses 32, 33 and the half mirror 34, and the half mirror 1 of the measuring means 10.
6 to the eye 2 to be examined.

Further, as shown in FIG. 3, the observation means 40 includes a total reflection mirror 41, a lens 42, and a video camera 4.
The video camera 43 captures an image of the subject's eye 2 via the half mirror 16 of the measuring means 10, the half mirror 34 of the fixation target system 30, and the relay lens 42. The subject's eye 2 captured by the video camera 43 is displayed on the viewfinder 6 shown in FIGS.

On the other hand, in FIG. 2, the projection means 20 is for projecting a ring pattern of a predetermined shape on the cornea of the eye 2 to be examined, and is attached to the periphery of the measurement window 4. FIG. 4 shows an enlarged view of the projection means 20. In FIG. 4, the projection means 20 is composed of a plurality of light emitting elements. Specifically, after arranging a plurality of light emitting diode chips 22 and 22 (generally about 15 to 36) on a circular substrate 21 at substantially equal intervals, the plurality of light emitting diode chips 22 and 22 is a translucent resin material 2
3 to be integrally sealed. The plurality of light emitting diode chips 22 and 22 are electrically connected by wiring (not shown) on the substrate 21 and supplied with power from a power supply (not shown) contained in the housing 3 to function as point light sources. It is supposed to.

Each of these light emitting diode chips 22
As shown in FIGS. 4 and 5, the LED is a non-sealed type that is not sealed with a resin material, unlike the LED used for the projection unit of the conventional optometry apparatus. Therefore, the interval between the plurality of light emitting diode chips 22 can be narrower than the case where a plurality of LEDs are arranged, and
0 The overall diameter is smaller.

As shown in FIGS. 3 and 4, the projection means 20 does not have a light guide member unlike the projection means of a conventional optometry apparatus, and can have a very small thickness in the direction of the optical axis 19. Specifically, it is formed to a thickness of about 1 to 2 mm.

The resin material 23 is made of a clear material in which no light scattering material is mixed.
As shown in FIG. 5, the surface of the light emitting diode 3 has a uniform and smooth shape so as not to scatter the light emitted from the light emitting diode chip 22.
22 is projected without being scattered, and FIG.
A pattern formed by arranging dot patterns in an annular shape as shown in FIG.

The mounting position of the projection means 20 will be described in more detail. As shown in FIG. 4B, the projection unit 20 is attached to an outer surface 3a of the housing 3 on the side of the subject's eye 2 of the measurement window 4 with an adhesive. It is arranged around the optical axis 19 of the measuring means 10 and is orthogonal to the optical axis 19 and concentric with the measuring window 4.

As described above, the projection means 20 in the apparatus 1
Is arranged on the outer surface portion 3a of the housing 3, and since the light guide member is not used for the projecting means 20 as described above, the light amount of the ring pattern of the projecting means 20 is greatly attenuated. It is projected on the eye to be inspected 2 without being performed. Therefore, the projection means 20 can also serve as an anterior segment illumination light source which is conventionally provided separately.

The operation of observing the corneal shape of the subject's eye 2 using the apparatus 1 will be described below. First, when the power of the present apparatus 1 is turned on, a plurality of light emitting diode chips 22, 22 of the projection means 20, shown in FIGS. Then, an annular projection pattern is formed without scattering the point pattern due to the light emission. This projection pattern is projected on the eye 2 to be inspected.

The eye to be inspected 2 illuminated by the light of the light emitting diode chip 22 and the reflected image of the projection pattern reflected by the eye to be inspected 2 are guided to the observation means 40 as shown in FIG. Are imaged and superimposed on the viewfinder 6 shown in FIGS.

Here, when the apparatus 1 is arranged at an optimum position with respect to the eye 2 to be examined, as shown in FIG. You can observe projection patterns that are separated from each other,
If it is too far or too close from the optimal distance,
As shown in (b), the pattern of each point is blurred, and the projected pattern in which the point patterns are in contact with each other can be observed. Therefore, the appropriateness of the arrangement of the device 1 can be determined based on a qualitative criterion such as whether the point patterns are separated from or in contact with each other, rather than a quantitative criterion such as the width of the projection pattern. Position can be reliably adjusted. Therefore, measurement errors due to working distance errors are less likely to occur.

The reflected image of the ring pattern projected in this manner has the same perfect circular shape as the ring pattern when there is no astigmatism in the cornea of the subject's eye 2, and has the elliptical shape when there is astigmatism. By observing the shape of the reflected image, the presence or absence of astigmatism can be observed.

Since the projection pattern composed of a combination of point patterns is a circle centered on the optical axis 19 of the measuring means 10, a ring pattern is applied to the eye 2 when the apparatus 1 and the eye 2 are aligned. By projecting and searching for the center position of this ring pattern, the center position of the optical axis 19 of the measuring means 10 can be easily grasped, and alignment becomes easy. In addition, when used as an anterior segment illuminating device for the eye to be inspected 2, the ring-shaped illumination can uniformly illuminate the eye to be inspected 2 from all directions. Obtainable.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea. Therefore, these different modes will be described below. First, the present invention may be applied not only to a refract keratometer, but also to any optometry apparatus including an automatic corneal curvature measurement apparatus and an objective eye refractive power measurement apparatus. For example, regarding the objective type eye refractive power measuring device, conventionally, there is no need to measure the distortion of the corneal shape or the like, and the projection means has not been incorporated, but as described above, in order to facilitate confirmation of the working distance, And an eye illumination device for the subject. In recent years, IOL surgery has become popular,
In order to select the IOL, the refractive power of the eye to be examined is measured during the operation. At this time, whether the viscoelastic substance injected into the anterior chamber to protect the cornea flows out onto the cornea is determined. It is effective to use the projection means in order to judge. Conventional projection means are complicated and expensive, so it is practically difficult to incorporate them into a refractive power measuring device. However, if the projection means is simple and low-cost as in the present invention, it can be easily incorporated. It is possible.

The position of the projection means 20 may be any position as long as it can be projected onto the subject's eye 2 without attenuating the projection light of the projection means 20. 3 is not limited to the outer surface portion 3a. For example,
A cutout may be provided in the housing 3 around the measurement window 4 and the projection means 20 may be fitted into the cutout.

The configuration of the projecting means 20 may be different from that described above as long as the projecting means 20 can be downsized. For example, when the light emitting diode chip 22 has excellent durability, the light emitting diode chip 22 may be exposed without being sealed with the resin material 23. Alternatively, the light emitting diode chip 22 may not be a non-sealed type, and may be a conventional sealed LED.
If the size of the LED can be reduced, this sealed LED may be used.

Alternatively, a diode emitting near-infrared light is used as the light emitting diode chip 22 and the observation means 4
By adopting a near-infrared-sensitive video camera 43 as the zero video camera 43, the ring pattern may not be seen by the subject, but may be seen only by the examiner. In this case, since the subject does not feel glare, the subject can observe the subject's eye 3 in a natural state without narrowing the subject's eye 2.

When the projection means 20 is arranged concentrically outside the measurement window, the size of the projection means 20
Depending on the color, the subject (especially an infant) may be attracted to the projection means, may not fixate on the fixation target of the apparatus, and may cause unstable measurement values. In such a case, it can be dealt with by covering the projecting means with a resin member that transmits the smoke illumination light flux and not directly exposing it. This is also effective in preventing static electricity and preventing deterioration of the light emitting diode chip 22.

[0033]

According to the first aspect of the present invention described above, a measuring means for measuring an eye to be inspected through a measuring window provided on an outer surface of the apparatus main body, and a predetermined means provided on a cornea of the eye to be inspected. In an optometry apparatus provided with projection means for projecting a pattern and observation means for observing the pattern projected on the eye to be inspected, the projection means includes a plurality of light emitting elements arranged around a measurement window. By forming the pattern, the diameter of the projection means can be reduced, and the light guide member can be omitted. Therefore, the projection means can be reduced in size, and the optometry apparatus can be configured simply and at low cost. In addition, since this is done, the projection light projected by the projection means reaches the subject's eye without any interruption.

Further, with this configuration, the projection light is not scattered by the light guide member, and a ring pattern in which point images are arranged in an annular shape can be projected. Therefore, unlike the case of simply projecting an annular ring pattern, an appropriate working distance between the apparatus and the subject's eye can be easily grasped by a qualitative criterion, and a measurement error can be reduced.

According to the second aspect of the present invention, since the plurality of light emitting elements are composed of a plurality of light emitting diode chips arranged on an annular substrate, a small projection means can be easily formed. it can.

According to the third aspect of the present invention, there are provided a plurality of light emitting elements provided around the measurement window, and the plurality of light emitting elements are used for measuring a corneal shape of an eye to be examined. By forming a pattern and illuminating the anterior segment of the eye to be inspected, the projection light of the projection unit is projected onto the eye to be inspected without being attenuated by the light guide member. It is not necessary to separately provide an anterior segment illumination light source. Therefore, the optometry apparatus can be configured more simply and at lower cost.

[Brief description of the drawings]

FIG. 1 is a side view of an optometry apparatus according to an embodiment of the present invention.

FIG. 2 is a front view of the optometry apparatus of FIG. 1;

FIG. 3 is a configuration diagram mainly illustrating an optical system of the optometry apparatus of FIG. 1;

FIG. 4 is an enlarged view of a projection unit, (a) is a front view,
(B) is a side view.

FIG. 5 is a sectional view of a main part of the projection means.

FIG. 6 is a reflection image of a ring pattern of the projection unit,
(A) shows a state where the working distance is matched, and (b) shows a state where the working distance is not matched.

FIG. 7 is an overall perspective view of a projection unit in a conventional optometry apparatus.

8A and 8B are reflection images of a ring pattern of the projection unit of FIG. 7, in which FIG. 8A shows a state where the working distance is equal, and FIG. 8B shows a state where the working distance is not equal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 This apparatus 2 Eye to be examined 3 Housing 4 Measurement window 4a Outer surface part 5 Grip 6 Viewfinder 10 Measurement means 11 Light source 12, 17, 32, 33, 42 Lens 13 Chopper 14 Motor 15, 16, 34 Half mirror 18 Light-receiving device 19 Optical axis 20 Projecting means 21 Substrate 22 Light emitting diode chip 23 Resin material 30 Fixation target means 31 Fixation target 40 Observation means 41 Total reflection mirror 43 Video camera 50 Projection means 51 Substrate 52 LED 53 Light guide member

Claims (3)

[Claims] 1. A measuring means for measuring an eye to be examined through a measuring window provided on an outer surface of an apparatus main body; a projecting means for projecting a predetermined pattern on a cornea of the eye to be examined; An optometry apparatus comprising: an observation unit for observing the pattern; wherein the projection unit forms the pattern from a plurality of light emitting elements arranged around the measurement window. 2. The optometry apparatus according to claim 1, wherein said plurality of light emitting elements comprise a plurality of light emitting diode chips arranged on an annular substrate. 3. A plurality of light emitting elements provided around the measurement window, wherein the plurality of light emitting elements form a projection pattern for measuring a corneal shape of an eye to be inspected, and form a projection pattern of the eye to be inspected. An optometry apparatus for illuminating an anterior eye part.