JP2775285B2 - Eye refractive power measuring device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eye refractive power measuring device, and more particularly to an eye refractive power measuring device useful for children to infants.

[Prior Art] Conventionally, as an eye refractive power measuring device, there are a so-called subjective ophthalmoscope for measuring eye refractive power based on a response of a subject, a so-called auto-refractometer for objectively measuring an eye to be examined, and the like. Devices are known.

However, when measuring infants with this kind of device, it is not possible to measure with a subjective ophthalmoscope because of the lack of cooperation of infants, and the position of the eye to be examined must be fixed with a general auto-refractometer. However, in the case of infants, it is difficult to fix the position of the eye to be examined, and the measurement is extremely difficult.

In order to eliminate these drawbacks, the so-called photorefraction method of proving the fundus of the eye to be examined with a strobe light, photographing the state of the luminous flux at the pupil of the eye to be examined with a camera, and measuring the eye refractive power of the eye to be inspected from the result. Measurement methods have been proposed.

In this photorefraction method measurement, it is possible to measure sufficiently even if the optical axis of the eye to be examined is slightly shifted, and it is useful for measuring the eye refractive power of infants who have difficulty fixing the eye to be examined. It is supposed to be.

[Problems to be Solved by the Invention] However, in such a photorefraction type eye refractive power measuring apparatus, a strobe light source illuminates the optical axis of a camera from an oblique direction, and a pupil image at that time is simply taken. There is a problem that there is a diopter value that cannot be measured depending on the position of the light source, and that the measurable range is narrow.

Further, in this type of apparatus, measurement of astigmatism such as astigmatism degree and astigmatic axis angle has not been taken into consideration.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an eye-refractive-power measuring apparatus capable of obtaining a measurement result instantaneously and measuring an astigmatic degree, an astigmatic axis angle, and the like.

Means for Solving the Problems The present invention has a projection system for projecting a light source image on the fundus of the eye to be inspected, and a light receiving element arranged at a position substantially conjugate with the pupil of the eye to be inspected. An eye-refractive-power measuring device having a light-receiving system for guiding the light to the light-receiving element, wherein an edge-shaped light-shielding member is disposed in the optical path of the light-receiving system so as to be rotatable about the optical axis on a plane perpendicular to the optical axis. A light-reflecting power at each of at least three rotation positions of the light-shielding member, and measuring a refracting power of the eye. A light source having a plurality of light source units arranged and selectively turned on in different meridian directions around the center is provided, and an optical axis corresponding to the plurality of light source units in a plane perpendicular to an optical axis in the light receiving system optical path. At least 3 around
A light-shielding member having an edge-shaped ridge line perpendicular to the meridian direction is arranged, and the eye refractive power can be measured from each light amount distribution state on the light receiving element when the plurality of light source units are selectively turned on. And, the projection system is provided with a light source having a plurality of light source units arranged in different meridian directions about the optical axis in a plane perpendicular to the optical axis, and in a plane perpendicular to the optical axis in the light receiving system optical path. A light-shielding member having at least three edge directions perpendicular to the meridian direction corresponding to the plurality of light source sections and perpendicular to the meridian direction, and for separating each light beam transmitted through the edge-like edge line and leading the light beam to the light receiving element. The light beam separating means is provided so that the eye refractive power can be measured from each light amount distribution state on the light receiving element, and at least three light receiving systems are provided to separate the reflected light beam toward each light receiving system. A light beam separating means provided on the optical axis of the eye to be inspected; An edge-shaped light shielding member is provided in each of the light receiving systems, and in each of the light receiving systems, eye refractive power in different meridian directions can be measured from the light amount distribution state on the light receiving element. Is what you do.

[Operation] The state in which the light-shielding member blocks light is different depending on the eye refractive power of the eye to be examined. The light-shielding state corresponds to the eye refractive power, the eye refractive power can be measured based on the state of the light beam projected on the light receiving element, that is, the shape and the light amount distribution, and the eye refractive power for three meridians is obtained. Is measured.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

Astigmatism is caused by a difference in eye refractive power (diopter value) at each meridian, and the state of astigmatism can be specified by measuring the sphericity S, the astigmatic degree C, and the astigmatic axis angle A. Further, Deoputa value D _theta and the spherical degree S at meridian arbitrary angle theta, astigmatic degree C, the relationship between the astigmatic axis angle A is represented by the following formula.

D _θ = S + C sin (θ−A) (1) Accordingly, if the diopter values of the three meridians θ ₁ , θ ₂ , and θ ₃ are obtained, the spherical power S, the astigmatic power S, and the astigmatic axis angle A are obtained. The state can be specified.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

1 is a projection system for projecting a light source image onto the fundus 7 of the eye 3 to be inspected, 2 is a light receiving system for receiving the light beam 10 reflected by the fundus 7, and the projection system 1 and the light receiving system 2 are It is arranged to face the optometry 3.

The projection system 1 includes a light source 4 and a half mirror 5 for reflecting a light beam 11 from the light source 4 toward the subject's eye 3. The projection system 1 transmits the light beam 11 from the light source 4 onto a fundus 7 through a pupil 6. Is projected so as to form an image of the light source 4.

The light receiving system 2 includes an objective lens 8 and a light receiving element 9, and a light beam 10 from the fundus 7 passes through the half mirror 5 and is guided onto the light receiving element 9.

The light receiving element 9 is an area CCD, an image pickup tube, or an aggregate of two or more light receiving elements. The light receiving surface 9a of the light receiving element 9 is disposed at a position conjugate with the pupil 6 of the eye 3 with respect to the objective lens 8.

In the optical path of the light receiving system 2, at a position where a light source image is formed when the eye refractive power of the eye 3 to be examined is a reference diopter value,
An edge-shaped light blocking member 12 for blocking one side of the light beam 10 with the optical axis O of the objective lens 8 as a boundary is disposed in a plane perpendicular to the optical axis.

The light-shielding member 12 is supported by a roller 20 or the like so that the edge-like ridge line 15a of the edge portion 15 matches the optical axis of the light receiving system 2 and is rotatable about the optical axis.

An arithmetic unit 13 is connected to the light receiving element 9, and the arithmetic unit 3 calculates the light receiving state of the light receiving element 9 and outputs the result to the display 14.

 The operation will be described below.

As mentioned above, the measurement of astigmatism can be obtained by measuring the diopter value of three meridians. First, the measurement of the diopter value of one meridian will be described with reference to FIGS. 3 to 11.

As shown in FIG. 3 (A), when the diopter value of the subject's eye 3 is a negative diopter value compared to the reference diopter value, the image of the light source 4 is formed in front of the fundus 7, and this light flux causes Considering the light beam 10 reflected at one point on the optical axis among the illuminated fundus 7, the light beam 10 is condensed in front of the light shielding member 12, that is, on the side of the eye 3 to be examined, and is received by the objective lens 8. The upper half (hatched portion) of the light beam projected onto the element 9 is shielded. On the other hand, as shown in FIG. 3B, when the diopter value of the eye to be examined is the reference diopter value,
Is focused on the light shielding member 12, and the light flux 10 is a light shielding member.
Unobstructed by 12.

Also, as shown in FIG. 3 (C), when the diopter value of the eye 3 to be examined is more positive than the reference diopter value, the image of the light source 4 is projected so as to form an image behind the fundus 7, and as described above. Similarly, the light beam 10 reflected by the fundus 7 is collected behind the light shielding member 12, that is, on the light receiving element 9 side, and the light beam 10 projected on the light receiving element 9 is a portion opposite to that of FIG. The light flux (the upper half in the figure) is shielded.

Thus, the light flux projected on the light receiving surface 9a changes its light quantity distribution state with respect to the reference diopter value depending on the magnitude of the diopter value of the eye to be inspected 3 and the sign thereof, and the diopter value is determined based on this light quantity distribution state.

The light receiving element 9 is for detecting the light amount distribution of the light beam formed on the light receiving surface 9a, and the arithmetic unit 13 is configured to detect the light amount distribution of the light beam formed on the light receiving surface 9a based on the signal from the light receiving element 9. Detects the light amount distribution, determines whether the eye refractive power of the subject's eye is positive or negative with respect to the reference diopter value, calculates the absolute value, outputs the calculation result to the display 14, and the display 14 calculates Display the results.

In the above embodiment, a half mirror is used as a light beam separating means. However, it is a matter of course that various light beam separating means such as a beam splitter and a polarizing prism are used.

4A to 4E, the distribution of the amount of light of the light beam formed on the light receiving surface 9a will be described.

In order to simplify the explanation in FIGS. 4 (A) to 4 (E), the optical axis of the light source 4 and the optical axis of the light receiving system are matched, and the light shielding member 12 and the objective lens 8 are matched. I have. For this reason, the light source 4 and the objective lens 8 are shown superimposed at the same position, and the light shielding member 12 is omitted.

FIG. 4 (A) ~ (E) is the light receiving surface by all reflected light beam objective lens 8 from the shows the case where the refractive power D of the eye is negative with respect to the reference power D _0, the following description fundus It shall be projected on 9a.

Assuming that the distance between the light source 4 and the pupil 6 of the subject's eye is set to 1 and the refractive power of the subject's eye at which the image of this light source is focused on the fundus is the reference refractive power D ₀ It is.

FIG. 4 (A) shows a case where the refractive power of the subject's eye is D (<D ₀ ) from one point S ₀ on the axis of the slit-like light source 4 having a length L in a direction perpendicular to the optical axis. Indicates the projected light flux,
The image of the point S ₀ is once formed on S ₀ ′,
Projected as a blurred image. Region 7a where D ₀ -D is projected in accordance with increase becomes wider.

FIG. 4 (B) shows the state of the light beam reflected from the light receiving system 2 and the fundus 7 of the eye to be examined.

As shown in FIG. 4 (B), considering the light flux from a point I- _n at the end of the projection area on the fundus 7 of the eye to be examined, an image I- _n 'of this point is considered.
Is imaged at a position 1 'away from the pupil of the eye to be examined, and this light beam is projected via the objective lens 8 onto a light receiving element 9 arranged at a position conjugate with the pupil 6 of the eye to be examined. The relational expression between l 'and the refractive power D of the eye to be examined is as follows.

On the other hand, assuming that the pupil diameter of the subject's eye is u, the spread width Δ of the light flux emitted from one point on the fundus is as shown in FIG. 4 (B). From the first and second equations. Thus, as the difference between the refractive power D of the eye 3 to be examined and the reference refractive power D ₀ increases, the spread on the light shielding member 12 increases.

Next, the spread of the light beam on the light receiving element 9 will be described. The light receiving element 9 is always irrespective of the refractive power of the eye 3 to be inspected.
Assuming that the diameter of the pupil 6 of the eye to be examined is u and the magnification of the objective lens 8 is β, the region of the diameter of βu on the light receiving element 9 (the refractive power of the eye to be examined) Is unaffected by the light beam.

Also, after the imaged also similar light flux from the eye pupil 6 'image I _n to the position of' l from I _-n and control point I _n with respect to the optical axis, the same area on the light receiving element 9 projected onto βu. Light source 4
As a point light source, when that there is no light blocking member 12 is, those points I _-n from these fundus _{7, ... I 0, ... I} n, the integral of the light beam from determining the light intensity distribution on the light receiving element 9 It is.

Here, in order to consider the light amount distribution on the light receiving element 9, the light flux incident on the end position P _-n of the light beam projection position on the light receiving element 9, that is, the coordinate position -βu / 2 centered on the optical axis. In consideration of the above, the light beam incident on this position is limited to the light beam in the range of the oblique line A in FIG. 4 (C).
Similarly, considering the light flux incident on the position _Pn symmetrical to the P- _n position with respect to the optical axis, the light flux is limited to the light flux in the range of the hatched line A '. When an edge-shaped light-blocking member 12 that blocks one light beam A ′ of the optical axis is arranged at a distance of 1 from the pupil 6 of the eye to be examined (a position conjugate with the light source 4), P ₋ light beam incident on the position of the _n is not blocked by the light shielding member 12, the light beam toward the upper position from the position of the P _-n is gradually shading, half of the light beam is blocked by the center P ₀ position, P _n In this position, all the light beams are blocked. Therefore, the edge-shaped light shielding member 12
As a result, the light becomes darker on the light receiving element 9 as it goes upward, and the light quantity distribution has a constant slope where the light quantity becomes 0 at the point _Pn .

4 (A) to 4 (C) show only a light beam emitted from one point on the optical axis of the light source 4, but one point S- _n at the end of the light source 4 (where the size of the light source is L) Considering the luminous flux from the point (−L / 2 coordinate position), the result is as shown in FIG. 4D. Light beam from the point S _-n are projected from I _-n point on the fundus 7 shown in FIG. 4 (D) in the region of I _n points, this I _-n
Point, the reflected light from I _n points, after forming an image of, I _n '' I _n at a distance of 'l from the eye pupil 6 in the same manner as described above, the diameter of βu on the light receiving element 9 Is projected on the area of.
Here, of the luminous flux emitted from the point S- _n at the end of the light source 4,
The light beam incident on the end position P- _n of the light beam projection on the light receiving element 9 is a light beam in a hatched area B in FIG. 4D.

Further, the S consider the light beam from one point S _n of the point symmetrical with the light source 4 _-n, of which FIG. 4 Given the light beam incident on the point P _-n on the light receiving element 9 C of (E) It becomes the light flux in the shaded area. As described above, when the light source 4 is considered to have a certain size, the amount of light at one point on the light receiving element 9 must be considered as the sum of the light flux from each point of the light source 4.

FIG. 5 (A) shows the respective light beams incident on the position of P- _n on the light receiving element 9 based on this concept, and shows the light beams emitted from the position of S- _n on the light source. Of which P _-n
Is incident on the area B (FIG. 4 (D)).
See), the light beam according to the position on the light source goes upward also moves upward, the reference becomes a light flux area of the light source position S ₀ in A on the axis (FIG. 4 (C)), on the light source the light beam C region at the position of S _n (see FIG. 4 (E)). Therefore, the light quantity at the point P- _n on the light receiving element 9 can be considered as the sum of these light fluxes.

Here, a light shielding member is provided at a position of a distance 1 from the pupil 6 of the eye to be examined.
FIG. 5A is a schematic diagram showing the light amount at the point P- _n on the light receiving element 9 when 12 is arranged. FIG. 5A shows how the light beam is blocked by the light blocking member 12 as the position on the light source changes. The horizontal axis in FIG. 5 (B) indicates the coordinate position on the light source, and the vertical axis indicates the light amount.
Considering the luminous flux from each point on the light source, -L /
The light beam from the point 2 (L is the size of the light source) to the point 0 is not blocked by the light blocking member 12, but is gradually blocked after passing the coordinate point 0, and the light flux is all Is to be blocked. Here, FIG. 5 (B) shows the contribution of the light amount from each point on the light source, where k is the light amount from each point on the light source when no light is shielded. This corresponds to the light amount value at the point P- _n . This area value T is as follows.

Similarly, other points on the light receiving element will be considered. Figure 6 (A) have the meanings indicated in the same manner as Figure 5 a light beam incident on the center point P ₀ on the light receiving element (A), an inner P of the light beam from a point S _-n on the light source _The light flux incident on the point _{0 is} a shaded area of B ₀ , the light flux from the point S ₀ on the light source is the shaded area of A ₀ , and the light flux from the point S _n on the light source is the light flux of the shaded area C _0. is intended, the amount of light incident on the center of the light receiving element 9 will correspond to the area T ₀ of the shaded area of the diagram the 6 (B). That is, considering the light flux incident on the center point of the light receiving element from each point of the light source, -Δ /
The luminous flux is not blocked until the position of 2, and after passing the -Δ / 2 position, the luminous flux is gradually blocked, and all the luminous flux is blocked at the position of Δ / 2. The following values are calculated.

Similarly, FIGS. 7A and 7B show the state of the light beam incident on the point _Pn on the light receiving element and the light amount value at this point. In Figure 7 (A), hatched A "is the light beam incident on the point of the inner P _n of the light beam from the point S _-n on the light source is shaded region of B ', the center point S ₀ on the light source The luminous flux from the point P- _n on the area and the light source is shown as a luminous flux in the hatched area C ". In this case, as shown in FIG. 7 (B), considering the light flux incident from each point of the light source to the point P _n of the light receiving element,
From the position of -L / 2 on the light source to the position of -Δ, the light beam is not blocked, and after passing the -Δ position, the light beam is gradually blocked, and all the light beams are blocked at the position of 0, When this area value is calculated, the following value is obtained.

As can be seen from the results of these equations (6), (7), and (8), the light amount value on the light receiving element 9 gradually decreases as going upward from below. When the light quantity distribution on the element is illustrated, it changes linearly as shown in FIG.

In the above description, the description has been made on the assumption that the spread width Δ on the light blocking member 12 when considering the light flux emitted from one point of the fundus is smaller than 1/2 of the size L of the light source. It is.

However In other words, when the deviation ΔD of the diopter value of the subject's eye with respect to the reference diopter value D ₀ is equal to or larger than a predetermined amount,
A linear change as shown in the figure is not shown. This will be described with reference to FIGS. 5 to 7. As aforementioned In the case of FIG. 5, FIGS. 5 (B), 6 (B), and 7 (B) are as shown in FIGS. 12, 13, and 14, respectively. As shown in FIG. 8, no linear change is shown.

Next, when the refractive power of the subject's eye shown in FIG. 3 (B) is the reference value, and when the refractive power of the subject's eye shown in FIG. 3 (C) is more positive than the reference value, the same as described above. The light amount distribution on the light receiving element 9 can be considered. In this case, when the refractive power of the eye to be examined is a reference value, as shown in FIG. The distribution state is opposite to that shown in FIG.

The diopter value (refractive power) is the slope of the light amount distribution described above.
And the direction of the slope represents the sign of the diopter value. This will be described below with reference to FIG.

The slope of the light distribution Is defined as The spread Δ of the light beam, that is, the amount of blur Δ, is given by the above equation (5). Therefore, from equation (7) Thus, equation (11) gives the deviation ΔD of the diopter value of the subject's eye with respect to the reference diopter value D ₀ . Are proportional. Therefore, from the light intensity distribution , It is possible to obtain the diopter value of the eye to be examined.

The diopter value for one meridian can be obtained as described above, but the diopter values for the other two meridians may be obtained at positions where the light shielding member 12 is rotated, for example, by 60 ° and then by 120 °.

That is, if three rotational positions of the light shielding member 12 are selected and the diopter value at each position is measured, the spherical power S, the astigmatic power C, and the astigmatic axis angle A can be immediately obtained by the above equation (1).

Next, a second embodiment of the present invention will be described with reference to FIG.

In the second embodiment, the light source 16 has a plurality of light sources 16a, 16b, 16c... As shown in FIG. 16a, 16b, 16c... On a meridian different from the optical axis by θ at a position separated from the optical axis by a required distance in a plane perpendicular to the optical axis of the projection system 1, for example,
It is provided on the meridians of 60 °, 120 °, etc. The light shielding member 17 is provided with a hexagonal hole 18 as shown in FIG. 17, and is arranged such that the center of the hole 18 coincides with the optical axis of the light receiving system 2. Further, the corner edges 18a, 18b, 18c of the hexagonal hole 18 are formed.
Are perpendicular to the meridian to which the light source sections 16a, 16b, 16c... Belong, and at positions corresponding to the light source sections 16a, 16b, 16c. To be done.

In the second embodiment, at least three light sources on different meridians (excluding the other light sources extending in the meridian), for example, 16a, 16b, and 16c, are selectively turned on one by one. By performing the same measurement as in the above, the diopter value at three meridians is obtained, and the spherical power S, the astigmatic power C, and the astigmatic axis angle A are immediately obtained from the equation (1).

FIG. 18 shows a third embodiment, which has the same configuration as the light source 16 shown in the second embodiment.
A light source 16 'in which the light sources 16a, 16b, 16c ... do not blink, and a light-shielding member identical to that shown in the second embodiment
And a light beam separation device for separating the light beams from the respective light source units 16a, 16b, 16c... From the optical axis of the light receiving system 2, that is, in a direction away from the optical axis between the light shielding member 17 and the objective lens 8. For example, a deflection prism 19 is provided. The deflection prism 19 is formed by radially assembling prism pieces 19a, 19b, 19c,... Corresponding to the respective light source sections 16a, 16b, 16c,.

In this embodiment, the luminous flux from each of the light sources 16a, 16b, 16c.
Since the light is projected to different positions on the light receiving surface 9a, if the diopter value is obtained in the same manner as described above at each projected portion of the light receiving surface 9a, a plurality of diopter values in the meridian direction can be obtained at the same time. , Sphericity S, astigmatic power C, and astigmatic axis angle A are also determined.

 FIG. 20 shows a fourth embodiment.

The light source 4 is disposed at a position facing the eye 3 to be examined, and the light source 4 is covered by a light receiving system 2x, 2y, 2z having an optical axis intersecting the optical axis in a plane including the optical axis of the eye 3 to be inspected. It is arranged sequentially from the optometry 3 side. Thus, half mirrors 5x and 5x are placed on the optical axis of the eye 3 to be examined.
The light beams from the fundus 7 are split and reflected toward the light receiving systems 2x, 2y, 2z.

Here, the light receiving surface of the light receiving element 9x, 9y, 9z of the light receiving system 2x, 2y, 2z
9xa, 9ya, and 9za are conjugated to the pupil 6 of the subject's eye 3 with respect to the objective lenses 8x, 8y, and 8z in the same manner as in the previous embodiment. The light shielding members 12x, 12y, and 12z are located at the positions.
The position further rotated by 60 °, the light shielding member 12z is a position further rotated by 60 ° with respect to the optical axis than the light shielding member 12y.

With such a configuration, the diopter value obtained from the light receiving results of the light receiving elements 9x, 9y, and 9z is a value in the direction of three meridians, and can be measured simultaneously.

In the embodiment shown in FIG. 20, the light receiving systems 2x, 2y, 2z
Are completely identical, and the directions of the split reflection by the half mirror are changed to 60 ° and 120 ° with respect to the optical axis of the eye 3 to be inspected, and the light receiving systems 2x, 2y, and 2z are radial with respect to the optical axis of the eye 3 to be inspected. Even in such an arrangement, it is possible to obtain diopter values in three meridian directions in the same manner.

In the first, second, third, and fourth embodiments described above, the diopter value on three meridians may be obtained in order to specify the astigmatism state. Of the light-shielding member in the first and fourth embodiments.
12 and 12x, 12y, and 12z are further rotated, and in the second and third embodiments, the light sources are located at symmetrical positions and the edges are located at opposite positions. The influence of partial turbidity of a transparent body such as a corneal lens can be eliminated, and the measurement accuracy is further improved.

In the above embodiment, a half mirror is used as the light beam separating means of the projection system. However, it goes without saying that various light beam separating means such as a beam splitter and a polarizing prism can be used. Further, in the measurement of astigmatism, it is preferable to obtain a diopter value on three meridians, but the state of astigmatism is generally represented by two meridian directions (two meridian directions in a right angle relationship). The hexagonal light shielding member may be a rectangular light shielding member.

[Effects of the Invention] As described above, according to the present invention, diopter values for a plurality of meridians can be measured, measurement for astigmatism is realized, and the light receiving system uses a light receiving element. It has an excellent effect of being obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a basic structural diagram showing a first embodiment of the present invention, and FIG.
The figure is a view taken in the direction of arrows AA in FIG. 1, and FIGS. 3 (A), (B) and (C).
FIGS. 4A and 4B are explanatory diagrams showing the difference in the state of the light beam due to the difference in the diopter value of the eye to be examined in the embodiment; FIGS.
(C), (D) and (E) are explanatory views showing the state of the light receiving system and the state of the reflected light flux from the fundus of the eye to be examined. FIGS. 5 (A), 6 (A) and 7 (A) are light receiving elements. FIGS. 5 (B), 6 (B), and 7 (B) show the state of the reflected light flux at each point of the light source reaching the light source, and FIG. FIG. 8, FIG. 9, FIG.
FIG. 10 is an explanatory diagram showing a light amount distribution state on the light receiving surface corresponding to the diopter value, FIG. 11 is an explanatory diagram for obtaining a diopter value from the light amount distribution state, FIG. 12, FIG. 13, and FIG. FIG. 15 is an explanatory diagram showing a change in the amount of light of each light beam when light is shielded by a light shielding member when the spread width Δ on the member is larger than half the size of the light source. FIG. 15 is a basic configuration showing the second embodiment. FIG. 16, FIG. 16 is a view taken in the direction of arrows BB in FIG. 15, and FIG.
FIG. 15 is a view taken in the direction of arrows CC, FIG. 18 is a basic configuration diagram showing the third embodiment, FIG. 19 is a view taken in the direction of arrows DD in FIG. 18, and FIG.
It is a basic block diagram which shows Example of this. 1 is a projection system, 2,2x, 2y, 2z is a light receiving system, 3 is an eye to be examined, 4,16,1
6 ′ is a light source, 5,5x, 5y, 5z is a half mirror, 8,8x, 8y, 8z is an objective lens, 9,9x, 9y, 9z is a light receiving element, 12,12x, 12y, 12z, 1
Reference numeral 7 denotes a light shielding member, and reference numeral 19 denotes a deflecting prism.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yasuhisa Ishikura 75-1 Hasunuma-cho, Itabashi-ku, Tokyo Tokyo Optical Machinery Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) A61B 3/10

Claims (4)

(57) [Claims] A projection system for projecting a light source image onto the fundus of the eye to be examined, and a light receiving element disposed at a position substantially conjugate with the pupil of the eye to be examined, and a light beam reflected from the fundus of the eye to be guided to the light receiving element. An eye-refractive-power measuring apparatus having a light-receiving system, wherein an edge-shaped light-blocking member arranged rotatably about the optical axis on a plane perpendicular to the optical axis is provided in an optical path of the light-receiving system; An eye-refractive-power measuring device, characterized in that the eye-refractive power can be measured from each light amount distribution state on the light receiving element at at least three rotational positions. 2. A projection system for projecting a light source image on the fundus of the eye to be inspected, and a light receiving element arranged at a position substantially conjugate with the pupil of the eye to be inspected, for guiding a light beam reflected from the fundus of the eye to the eye to the light receiving element. In the eye-refractive-power measuring apparatus having a light receiving system, the projection system includes a light source having a plurality of light source units which are arranged in different meridian directions around the optical axis on a plane perpendicular to the optical axis and are selectively turned on. At least 3 centered on the optical axis corresponding to the plurality of light sources in a plane perpendicular to the optical axis in the optical path of the light receiving system.
A light-shielding member having an edge-shaped ridge line perpendicular to the meridian direction is arranged, and the eye refractive power can be measured from each light amount distribution state on the light receiving element when the plurality of light source units are selectively turned on. An eye-refractive-power measuring device, characterized in that: 3. A projection system for projecting a light source image on the fundus of the eye to be inspected, and a light receiving element arranged at a position substantially conjugate with the pupil of the eye to be inspected, for guiding a light beam reflected from the fundus of the eye to the eye to the light receiving element. An eye refractive power measuring device having a light receiving system, wherein the projection system is provided with a light source having a plurality of light source sections arranged in different meridian directions about the optical axis on a plane perpendicular to the optical axis, A light-shielding member having an edge-shaped ridge line in a plane perpendicular to the optical axis and corresponding to at least three meridian directions centering on the optical axis and corresponding to the plurality of light sources, and penetrating the edge-shaped ridge line. An eye-refractive-power measuring device, characterized in that a light-beam separating means for separating each light beam and leading the light beam to a light-receiving element is provided so that the eye-refractive power can be measured from each light amount distribution state on the light-receiving element. 4. A projection system for projecting a light source image on a fundus of a subject's eye, and a light receiving element arranged at a position substantially conjugate with a pupil of the subject's eye, for guiding a light beam reflected from the fundus of the subject's eye to the light receiving element. An eye refractive power measuring device having a light receiving system, wherein at least three sets of light receiving systems are provided, and a light beam separating means for separating the reflected light beam toward each light receiving system is provided on the optical axis of the eye to be inspected; Are provided with edge-shaped light-shielding members, respectively, so that in each light-receiving system, eye refractive power in different meridian directions can be measured from the light amount distribution state on the light-receiving element. Force measuring device.