JPH027934A - Apparatus for measuring eye refractivity - Google Patents

Abstract

PURPOSE:To simplify the structure of a measuring optical system by using a light source in both of the illumination light source in an illumination optical system and the collimation light source in a collimation optical system in combination. CONSTITUTION:A measuring optical system 8 has an illumination optical system and a monitor optical system. The illumination optical system has a plurality of spot light sources 30 arranged at the positions symmetric to the optical axis of measuring light, which is set so as to be projected on an eye E to be examined, in the peripheral direction around said optical axis. The monitor optical system has a prism 17, a dichroic mirror 31, reflecting mirrors 25, 35 and a light detection sensor 29 and displays the relative positional relation between the set position of the optical axis of the measuring light and the center position of the cornea reflecting pattern of a plurality of the spot light sources on a monitor means.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an eye refractive power measurement device that objectively measures the eye refractive power of an eye to be examined.

[Prior art and its problems]

In general, various refractometers and autorefractometers are known as devices for objectively measuring eye refraction. These refractometers are devices that objectively measure the refractive power of the eye by observing through an optical system whether the light species is correctly imaged on the fundus or retina of the eye being examined. An autorefractometer is a device that automatically performs measurements and calculates the degree of refraction from the measured values. Therefore, a refractometer has a measuring optical system that includes a measuring light projecting optical system that projects the light type and a measuring light receiving optical system that observes the light type on the retina, such as a light source, mirror, lens, or prism. It has a complex structure with various optical devices. In addition, in actual measurement, as a preliminary preparation for measurement, the positional relationship between the measurement optical system on the device side and the eye to be examined must be adjusted to a measurable state (aimed and focused state). In conventional autorefractometers, this adjustment is automatically performed, and the optical system for this purpose aligns the optical axis of the measurement light with the optical axis of the eye to ensure that the measurement light is correctly directed into the center of the pupil. In order to match the measurement light, the aiming optical system is equipped with an aiming optical system that aims and focuses the measurement light using corneal reflected light from an aiming light source placed on the optical axis of the measurement light, and also monitors the eye to be measured and determines the alignment state. It is equipped with a monitor photographing optical system for displaying the in-focus state as a monitor image, and an illumination optical system having an illumination light source arranged to illuminate the subject's eye from its surroundings for monitor photographing. The measurement optical system was configured by a complex combination of these optical systems.

[Purpose of the invention]

An object of the present invention is to provide an eye refraction measuring device that can contribute to simplifying the structure of a measurement optical system by serving both as an illumination light source in an illumination optical system and as an aiming light source in an aiming optical system.

[Means to solve the problem]

The eye refraction measuring device according to the present invention solves the problems of the prior art as described above, and is configured as follows in order to achieve the object. That is, in an eye refractive power measuring device equipped with a measuring optical system for objectively measuring the eye refractive power of the eye to be examined, the measuring optical system is set to project light onto the eye to be examined. an illumination optical system consisting of a plurality of point light sources arranged in a circumferential direction around the optical axis of the measured measurement light at positions opposite fE to the optical axis; and a position of the optical axis of the measurement light set as described above. and a monitor optical system for displaying the relative positional relationship between the plurality of point light sources and the center position of the corneal reflection pattern on a monitor means.

[Effect]

In the eye refraction measuring device according to the present invention, the corneal reflection pattern of the illumination light source that illuminates the eye to be measured is displayed on the monitor, and the position of the eye to be examined relative to the illumination light source can be known from this monitor display. That is, the illumination light source also serves as an aiming light source. There are a plurality of illumination light sources, and they are arranged symmetrically with respect to the optical axis of the measurement light so that the optical axis of the projected measurement light is located at the center of these illumination light sources. If the light sources are all equidistant from the optical axis of the eye to be examined, the monitor means will display that the center of the eye to be examined is located at the center of the corneal reflected light; If the optical axis of the eye to be examined is not located at the center of each illumination light source, the corneal reflection pattern will be displayed on the monitor with a deviation toward the side where the illumination light source is biased with respect to the eye to be examined. From this, the direction and amount of deviation of the aim can also be detected. Note that from the corneal reflection pattern of this illumination light source, it is also possible to detect whether or not the object is in focus using various well-known methods. In this way, since the illumination light source that illuminates the eye to be measured as the measurement target also serves as the aiming light source for adjusting the focusing and focusing conditions, the measurement optical system can be made smaller and simpler.

【effect】

As is clear from the above description, the present invention provides the following excellent effects. That is, since the illumination light source in the illumination optical system and the aiming light source in the aiming optical system are used, the structure of the measurement optical system is simplified.

【Example】

A preferred embodiment of the present invention will be described below with reference to FIGS. 1 to 20. FIG. 1 is a block diagram showing the schematic configuration of the eye refraction measuring device of this embodiment. As shown in the figure, it is roughly divided into two configurations: an optical measurement section 1 and a main body section 2. The optical measurement unit 1 has a measurement optical system built therein, and is constructed to have a size and weight that is a so-called handy type device that can be easily held with one hand and moved freely. An image signal from the optical measuring section 1 is input to the main body section 2, and an image recognition device 3 recognizes the contents of the signal, that is, the matching situation of aiming and focusing, and the other side displays the image signal as an image. Each monitor 4 is built-in. Also, it outputs a control signal to the optical measurement unit 1 while exchanging signals with both the image recognition device 3 and the monitor 4, and monitors the eye based on measurement data obtained from the image signal input to the image recognition device 3. A control circuit 5 for calculating the degree of refraction is also built-in. That is, when the measuring optical system is aimed at and in focus on the eye to be examined, the optical system starts measurement, and the eye refractive power is calculated based on the image signal from the optical measuring section l. The means will be constituted by the image recognition device 3 and the control circuit 5. In the figure, 6 is an operation switch for the control circuit 5, and 7 is a printer that prints and outputs the results calculated by the control circuit 5. The optical measuring section 1 and the main body section 2 only need to be connected by a cable (not shown) or wirelessly, and in any case, only the optical measuring section 1, which requires position adjustment with respect to the eye to be examined during measurement, is extracted. It is separated as a movement system so as to be movable with respect to the stationary main body 2, and therefore it is extremely easy for the examiner to hold it in his hand and perform position adjustment operations with respect to the eye to be examined. . FIG. 2 shows the measuring optical system 8 built into the optical measuring section 1 in this embodiment, and FIGS. 3 to 8 show the measuring optical system 8 as each element optical system constituting the measuring optical system 8. Light projecting optical system 9, measurement light receiving optical system 10, target optical system 11, monitor camera optical system 12, and monitor reticle optical system 1
A aiming optical system consisting of 3, and a monitor illumination optical system 14
Each of the elemental optical systems is shown separately. First, FIG. 3 shows the measurement light projecting optical system 9. An infrared light source is used as the light source 15 for projecting the measurement light, and the light [1
The measuring light emitted from the first reflecting mirror 16 is reflected upward at right angles. Above the optical axis a of the measuring light reflected upward at right angles, there is a first reflecting mirror 1 with respect to the optical axis a1.
A first prism 17 is disposed on the opposite side of the prism 6 and is joined at an angle of 45°. This first prism 17 is a half prism, which partially reflects infrared light at a certain ratio and transmits the rest, and transmits most of visible light. Therefore, by positioning the eye E on the optical axis a2 of the measurement light refracted at right angles by the first prism 17,
The measurement light can be projected into the eye E to be examined. Note that on the optical axis a3 between the light #15 and the first reflecting mirror 16,
Collimator lens 19 in order from the light source 15 side. Light projection pattern mask 20. A light emitting relay lens 21 is arranged, and the first
An eyepiece lens 22 is arranged on the optical axis a1 between the reflection mirror 16 and the first prism 17. The measurement light is projected from the projection light #15 and collimated by the collimator lens 19. Light projection pattern mask 202 stage optical relay lens 21. First reflecting mirror 16. Eyepiece lens 22. Through the first prism 17, from the pupil to the corneal surface, and through the crystalline lens, the eye to be examined E
enters the body and projects a pattern of light onto the retina. FIG. 4 shows the measurement light receiving optical system IO. The measurement light of the light receiving system becomes reflected light from the image of the light species formed on the retina of the eye E and travels backward along the optical axis at+a1 of the light projecting optical system 9, but the first reflection When it reaches the position of the mirror 16 (shown in FIG. 2), it passes through the first through hole 23 opened approximately in the center of the mirror 16. A diaphragm 24 is formed directly under the first through hole 23, and a second through hole 26 is formed in the approximate center of a second reflecting mirror 25 (shown in FIG. 2), which will be described later. is formed, and the first
The measurement light that has passed through the through hole 23 is further passed through the aperture 24 and the second
Pass through the hole 26 and go straight. Therefore, after passing through the first through hole 23, the optical axis a4 of the light-receiving system measurement light traveling in the opposite direction along the optical axis a, continues straight downward and passes through the imaging lens 27 and the filter 2.
8 to the light receiving sensor 29. FIG. 5 shows the monitor illumination optical system 14, which evenly surrounds the optical axis a5 of the monitor illumination optical system, and when the sight is aligned, the optical axis a is directed toward the subject's eye located above. Six infrared light sources are arranged as illumination light sources 30 so as to face the camera. In addition, this front axis a. coincides with the optical axis a of the measurement light. Since this illumination is based on infrared rays, the eye E to be examined has no sensation of light and does not feel dazzling. The illumination light from the above-mentioned illumination optical system 14 is reflected by the cornea of the eye E to be examined, and this reflected light is used as aiming light for aiming the optical measuring section 1 toward the eye E to be examined, and the monitoring camera optical system 12 is used as the aiming light for the eye E to be examined. Configure as shown. As shown in FIGS. 9 and 10, this illumination light is projected so that a parallel ray (beam) forming an appropriate inclination angle λ with respect to the optical axis a5 of the illumination optical system is directed toward the eye E. In this case, if the optical axis aE of the eye E is shifted from the optical axis a of the illumination optical system, six images (approximately point light sources) are created by the corneal reflected light (aiming light) of the six beams The center position (that is, the optical axis a2 of the eye E) is the optical axis a of the illumination optical system
Since a "shift" occurs with respect to , in principle, aiming can be performed by measuring the amount ε of this "shift" and setting it as O. Further, the corneal reflection bright spot of the illumination light source 30 is more than three times stronger than other video signals, and it is also possible to use this to detect the in-focus state. In other words, when focusing, this bright spot is the smallest and the focus is strongest, so this state can be detected by the image recognition device 3, and as in the aiming operation, it is possible to focus on the same object, the corneal reflection bright spot, and then Since detection is performed, both aiming and focusing operations can be detected at a relatively high speed, and immediate processing is possible. By aiming in this way, the optical axis of the measuring system, monitor system, etc. can be aligned with the optical axis ag of the eye E to be measured, and by focusing, the optical axis The distance between the measurement unit 1 and the eye E to be examined, and furthermore the distance between the eyepiece lens 22 of the measurement light projecting optical system 9 and the corneal surface of the eye E to be examined, can be set to a constant distance suitable for measurement. Behind the first prism 17 (which partially transmits infrared light) on the optical axis a of the illumination optical system 14 (with the illumination direction being the front), there is a dichroic mirror 31 that reflects infrared rays and transmits visible light. , are arranged at an angle of 45° with respect to the optical axis a so as to reflect the aiming light (infrared rays) downward at right angles. On the optical axis a8 bent downward at right angles by this dichroic mirror 31,
A second prism 32 is arranged, which is a half prism with characteristics substantially opposite to those of the first prism 17, that is, a half prism that transmits most of the infrared light and reflects most of the visible light. The aiming light reflected by the dichroic mirror 31 is
The light passes through the prism 32, goes straight downward along the optical axis a6, passes through the monitor relay lens 33 disposed below the second prism 32, and then enters the third reflection mirror 34 disposed below the second prism 32. . The aiming light is further reflected at right angles and reaches the second reflecting mirror 25 along the optical axis a7. The optical axis a7 intersects the optical axis a4 of the measurement light receiving system 10 on the plane of the second reflecting mirror 25, so to be more precise, the optical axis a7
They intersect within the through hole 26. The aiming light is further reflected downward at a right angle by the second reflecting mirror 25 and reaches the light receiving sensor 29 along the optical axis a. FIG. 7 shows the monitoring reticle optical system 13. A reticle/14i35 which is a visible light source for displaying a reticle of an aiming position indicator on the side of the second prism 32
．． Reticle pattern mask 36. Reticle objective lenses 37 are provided in this order, and the light irradiated from the reticle light source 35 passes through a reticle pattern mask 36 along the optical axis all to become its marker pattern light, and further passes through the reticle objective lens 37. The light reaches the second prism 32 and is refracted downward at a right angle. The reticle pattern is represented, for example, by concentric double circles, the inner circle of which indicates the minimum measurable pupil diameter, and the outer aperture drawn at the standard position where the corneal reflection image occurs. The optical axis a of the reticle light refracted downward at right angles by the second prism 32. The prism surface of the second prism 32 is arranged so as to coincide with the optical axis a8 of the aiming light. Therefore, the subsequent optical system is the same as the monitoring camera optical system 12. In this way, since the optical system of the aiming light after the second prism 32 and the optical system of the reticle light coincide, the center of the corneal reflected light of the six illumination lights is located above the optical axis a of the illumination optical system. For example, the center will coincide with the center of the mark pattern on the reticle, and if this coincidence is detected on one light receiving sensor 29, it will be detected that the aim is correct. Incidentally, in this embodiment, the reticle pattern is transmitted to the reticle light source 35 and the reticle pattern mask 3.
6 etc., but this reticle pattern only needs to display the aiming reference position on the monitor image, so for example, you can write the pattern on the monitor image (,
Alternatively, with respect to the monitor relay lens 33 on the monitor camera optical system 12, for example, a transparent glass plate that transmits infrared light is placed at a position conjugate with the subject's eye E, and a pattern is written on it, so that the light receiving sensor 29' It is also possible to have the system detect the pattern. FIG. 8 shows the target optical system II. Since the tichroic mirror 31 disposed on the optical axis a5 that has passed through the first prism 17 transmits visible light, the optical axis a5
If an object 38 is placed behind the dichroic mirror 31 on the extension of , the limb examiner can see the object 38 through the first prism 17 and the dichroic mirror 31, By looking directly, the optical axis aE of the eye E to be examined can be aligned approximately above the optical axis a. As described above, the illumination light source 30 also serves as a light source for aiming light, and the light receiving sensor 29 is configured to detect aiming light including reticle light as well as measurement light. The measuring optical system 8 itself is miniaturized, and is extremely advantageous in constructing the optical measuring section 1 into a handy type. Further, the illumination light source 30 is connected to an optometry window 39 as shown in FIG.
A disc member 40 rotatable around the optical axis a5 is attached to the housing (not shown) of the optical measuring unit l on the peripheral part of the optometry window 39. An illumination light source 3° is fixed to the member 40. A weight 43 is attached to this disc member 40 at a location where the two illumination light sources 30 are located on the horizontal reference radial line 42. This allows the disc member 40 and the illumination light sources 30 to
.degree., it is possible to always maintain a constant posture regardless of the inclination of the optical measuring section 1. Note that due to this structure, the illumination light source 3
There is a risk that unnecessary "shaking" may occur at 0, but since the aiming operation is originally performed carefully and quietly, there is no problem in practice. The control circuit 5 built into the main body 2 controls the illumination light source on the reference meridian 42 to blink separately from the other illumination light sources. If the attitude of the optical measurement unit 1 is inclined with respect to the horizontal direction, the reference meridian 4
The image recognition device 3 obtains the coordinates of the corneal reflection bright spots on the monitor caused by the illumination light source above. Control is performed such that only the illumination light source is turned on and the other bright light sources are turned off (the reverse control is also possible). This control operation is sufficient for a moment, and the examiner does not notice any unsightliness such as darkening of the monitor screen. In this way, the inclination angle of the optical measurement unit l with respect to the horizontal direction is obtained, so the correction is made by subtracting that angle from the value of the axis angle (AXIS), which is the measurement calculation result, to obtain an accurate value. is displayed in the output. Various patterns are possible as the pattern of the light projection pattern mask 2° of the measurement light projection optical system 9, for example, a circular pattern formed in an annular shape around the optical axis a2 and having a predetermined radius, or this circular pattern. Similarly, at a predetermined distance from the center, for example, every 900 degrees, every 60 degrees, or 45 degrees.
A spot pattern arranged at equal central angular positions is realistic. In the eye refractive power measurement apparatus of this embodiment configured as described above, the eye refractive power is measured by the measurement light emitting/receiving optical system 9.10 as follows. In FIG. 12, the measurement light is on the optical axis a in this embodiment. FIG. 3 is a perspective view showing an optical path that passes through the fixed point O above, enters the cornea, and reaches the retina. In the measurement light projecting optical system 9 that is aimed and in focus, its tip axis a coincides with the optical axis a8 of the eye to be examined on the Z axis in the figure, and the measurement light is directed along the optical axis a. , passes through the fixed point O above, enters a point P on the cornea, and reaches a point Q on the retina. Note that this fixed point O is the point where light is emitted from the measurement light light source 15 when the eyepiece lens 22 is located at a position where the aperture 24 and the corneal surface are conjugate with each other in the measurement light receiving optical system 10. This is the point at which the measured measurement light passes above the optical axis a after passing through the eyepiece lens 22. The distance between the retina and the cornea on the optical axis a6 is d, and the cornea and the fixed point O
Let the distance between the two be dl. The distance from the optical axis aE to the point P on the cornea is h1, and the inclination of the direction from the optical axis aE to the point P with respect to the X-axis direction is θ. Further, it is assumed that the long axis f1 of the refractive power of the eye to be examined lies in a direction inclined by φ with respect to the X-axis. Short axis f, is long axis f1
is perpendicular to The component in the long sleeve direction of this point P is P 11
+ If the component in the minor axis direction is P I2, then Pn=h+cos(θ-φ) (1) P r ! = h IS 1 n (θ−φ) (2)
It can be expressed as Similarly, for the image (point Q) projected onto the retina after receiving refractive power from this corneal surface, each component of the distance vsh from the optical axis aE in the r1 direction and the r, direction Q r I + Q
I 2 can be expressed as . If the eye refraction in the horizontal direction is the eye refraction in the vertical direction, then the following holds true. On the other hand, when the image of the light projection pattern projected onto the retina is viewed from the measurement light receiving optical system 10, the light of the light receiving system is selected by the aperture 24 arranged at a position conjugate with the cornea with respect to the eyepiece 22. Only the light beam near the axis passes through this aperture 24 and is guided to the imaging lens 27. The position of the diaphragm 24 is also the focal point of the imaging lens 27, and the image light that passes through the diaphragm 24 and enters the imaging lens 27 travels parallel to the optical axis and hits the light receiving sensor 29. Optical axis. The image is formed at a distance of . That is, in the light receiving system, an image is formed on the retina at a distance h from the optical axis, and an image similar to this image is formed on the light receiving sensor 29 from the optical axis. formed at a distance of Here, the inclination of the direction from the optical axis to point Q with respect to the X-axis direction is defined as ψ. Further, as assumed in the light receiving system, the long axis f1 of the refractive power of the eye to be examined is in a direction inclined by φ with respect to the X axis, and the short axis f is perpendicular to the long axis r1. And this h-tori. The relationship is expressed by equation (9). However, L is a constant determined by the focal length and arrangement of the eyepiece lens 22 and the imaging lens 27. From the above assumptions, Q l l and Q I2 in the light receiving system are (10
) and (11), and in each of these equations (9
) can be expressed as equations (12) and (13). Q,,=hcos(φ−φ) (
10) Q rt = h 5in (φ - φ) (11) Here, from equations (7) and (12), equations (8) and (13), the relationship between equations (14) and (15) holds true. Perform operations such as shifting terms and expansion in equations (14) and (15) to obtain hocosψ= S x, h, sinψ−
When Sx and Sy are determined as 3y, equations (16) and (17) are obtained. Sx Sy In equations (16) and (17), L-h, (1/d
, -D2)=A. When replacing t, -h, (1/d+-Dt) = B, 5
x=Acos(θ-φ)cosφ-Bsin(θ-φ)
sinφS y=A cos(θ−φ)sinφ+B
It is simply expressed as s1n(θ-φ)cosφ. In equations (18) and (19), the unknown to be measured is A
B, φ, and two values θ determined by the light projection pattern. S Xl+ for θ, respectively
These unknowns can be theoretically obtained from the four equations giving S 1'++ S Xt+ S )'t. In general, the correction value for refractive error is spherical power (SP
ll), cylindrical power (CYL), axis angle (AXIS), or 5PIl-D, CYL=D, -D2. A
xls=φteso, respectively. Here, the light projection pattern is, for example, on the two radial lines of the pupil passing through the optical axis a6 of the eye E to be examined, with a total of four
A spot pattern of dots is used. These two radial lines are horizontal and vertical radial lines, and in the case of θ, -〇〇, S x+・sxo+ S y+□5yosθ,=90
If we solve the above four equations as S Xt"SXe+S y2"SY9 in the case of
'+4Syot)) (20)B=l/2・f:Sx
o+5ye-4((Sxo-3y9)'4Syo'l:
] (21) is obtained. Therefore, as shown in FIG. 13, two points P on the X-axis and on the X-axis are projected onto the cornea using the spot pattern. , Po
As shown in FIG. 14, the light receiving sensor 29
Point S of the image formed above. , the coordinates of S8 (SXQI 5
By measuring yo) and (Sxe, SyJ with the image recognition device 3, the eye refractive power of the eye to be examined can be objectively known. Hereinafter, FIG. 15 is a measurement flowchart by the eye refractive power measuring device of this embodiment. , and each step will be explained in order. First, in step 100, the illumination light source 3 is turned on as a preparation mode.
0 and the reticle light source 35 are turned on, the measuring light projection light source 15 is turned off, and the process moves to step +01. Further, a timer interrupt by step 100° is also possible in step 00, and in this step 100', only the illumination light source 30 is on, and the reticle light 11iij3
5 and the projecting light source 15 are turned off. In the monitor image at this time, if the eye E to be examined is in front of the illumination light source 30, a group of bright spots and a reticle pattern due to the corneal reflected light of the illumination light will appear, and if the eye E to be examined is not present, only the reticle pattern will appear. appear. In step 1.01, it is determined whether the switch of the printer 7 is on, and if it is on, step 1.
After outputting from the printer 7 in step 02, the process moves to step 103, and if it is off, the process moves directly to step 103. In step 103, it is determined whether or not the eye E to be examined is in front of the illumination light #80. If there is, the process moves to step 104, but if not, the process returns to step 100 and the steps up to step 103 are repeated again. This determination can be made based on whether or not the corneal reflected light of the illumination light is detected by the light receiving sensor 29, and the examiner can also determine this on the monitor image. In step 104, the image recognition device 3 determines the coordinates (xo, yo) of the center of gravity position on the X-axis and y-axis of the bright spot group due to the corneal reflected light of the illumination light as the aiming detection mode, and the process proceeds to step 105. In step 105, the X coordinate (
It is determined whether the absolute value IX,l of If not, the process returns to step 100 and the steps up to step 105 are repeated again. In step 106, the X coordinate (
It is determined whether the absolute value 1 yol of y o) is smaller than the value of the y-axis deviation standard set as the allowable range of "deviation" in the X-axis direction, and if it is smaller, the process moves to step 107 and it is determined that If so, the process returns to step lOO and the steps up to step 106 are repeated again. In step 107, as a focus detection mode, a high frequency component (H,) of an image signal of a group of bright spots due to corneal reflected light of illumination light is detected.
is determined by the image recognition device 3, and the process moves to step 108. Note that this method of detecting the in-focus state by detecting high-frequency components is a method that can be realized only by software, but in a more general way, including methods using hardware, it is possible to detect a group of bright spots. The in-focus state may be detected by detecting the contrast state of . In step 108, it is determined whether the high frequency component (H2) obtained in step 107 is larger than the contrast reference value set as the allowable range of the in-focus state, and if it is larger, the process moves to step 109 and If not, the process returns to step 100 and the steps up to step 108 are repeated again. The aiming situation and focusing situation in steps 104 and 107 described above are the positional deviation situation between the Hashisenkuru pattern and the bright spot group and the core ! of the bright spot group on the monitor image.・The examiner adjusts the aiming status and focusing status (l'5 is added) from this monitor image. In step 109, as an angle correction mode, a group of bright spots due to the corneal reflected light of the illumination light is Of these, only the illumination light sources corresponding to the two bright spots on the base radius 42 are turned on, and the other illumination light sources, the measurement light source 15, and the reticle light source 35 are turned off, and the monitor image is manually displayed. Then, the process moves to step 110. In step 110, a straight line connecting the two bright spots shown on the monitor image in step 109 and a horizontal reference line (
(corresponding to the horizontal axis of the optical measurement unit l) is detected, and the process moves to step 111. In step 111, a state in which the illumination light source 30 and reticle light source 35 are turned off and the measurement light projecting light source 15 is turned on is input to the monitor image as a measurement mode, and the process moves to step 112. At this time, the image of the fundus pattern detected by the light receiving sensor +f7.9 by the measurement light receiving optical system 10 may appear momentarily as an image, but since the measurement has been completed at this point, each Regarding the light source,
Then, the process immediately moves to step 112, and the light source 15 of the measurement light is
is turned off, and the state is the same as the preparation mode in which the illumination light g30 and the reticle light source 35 are turned on. Step 112 moves to step 113, in which the measurement light receiving optical system lO in the measurement mode is
It is determined whether the signal level manually applied to the light receiving sensor 29 is high enough. This is because if the eye E to be examined has a cataract, it may not be possible to obtain an image signal of a level necessary for measurement, so this is checked in this step. If the signal level is high enough in step 113, the process moves to step 114 to enter a calculation mode, and if it is insufficient, the process moves to step 120 to perform error processing. To handle the error at step 120, for example, a message such as 'no target' may be displayed on the monitor screen at step 116, which will be described later. Based on this, the spherical power (SP!+), cylindrical power (CYL), and axial angle (AXI) of each element of the spectacle lens or contact lens are input.
S) is calculated. The calculation formula for each element is not uniform because the measurement points differ depending on the projection pattern, but as a relatively simple example, when projecting a total of four spot patterns with a center angle of 90°, each spot The X coordinate and the X coordinate (SX(+), (SX9),
(SXIll), (Sxt7), (Syo), (S
ys). (sy+a), (Syt7), and the spherical power (SPII), cylindrical power (CYL), and axial angle (AX Is) are determined by the following calculations. When the above calculations are completed, the process moves to step 115. In step 115, it is determined whether the numerical values of each element 5PII, CYL, and AXIS obtained in step 114 are within a reasonable numerical range, and if they are within a reasonable range, the process proceeds to the appropriate next step 116. However, if it is outside the reasonable range, the process moves to step 121 and error handling is performed. The error handling at step 121 is as follows:
For example, a message such as "try again" may be displayed on the monitor screen in step 116, which will be described later. In step 116, the calculation result in step 114 or the error processing result in step 120 or 121 is displayed on the monitor screen. Note that this step 116
As an output condition for displaying the calculation results, it is possible to switch between display for eyeglass lenses and contact lenses.In addition, it is possible to change the display for eyeglass lenses and contact lenses.In addition, it is possible to change the display level to determine how finely the calculation result values are displayed. (STEP value) can also be set. Further, the distance between the spectacle lens and the cornea (O in the case of a VD value contact lens) is set. - is also possible. When step 116 is completed, the process returns to step 100, the preparation mode. In the above embodiment, a case where a four-point spot pattern is used as the light projection pattern has been described, but as another spot pattern, a spot pattern of n points is projected onto each of n rays centered on the optical axis. By using the spot pattern and performing statistical calculations on each point, A, B, φ, spherical power (SPH), cylindrical power (CYL), and axial angle (AXIS) in the above example can be calculated.
) is obtained, and in this case, by setting n to a large value, the measurement accuracy can be dramatically improved. Further, the light projection pattern other than the spot pattern may be a continuous circular pattern around the optical axis.
In that case, the pattern projected on the retina is expressed by the equation of an ellipse, and the lengths of the long and short axes of the ellipse determine the eye refractive power in the water shell direction and the vertical eye refractive power. , can be easily determined, and the inclination angle of its long axis (axis angle)
can also be easily determined from the coordinates of the light receiving sensor -tt-H. Regarding the measurement method described in J-2, which uses a measurement optical system and a light projection pattern to calculate the degree of eye refraction, it is used in a measurement device in which the optical measurement section and the main body are separated, as in the present invention. Of course, the present invention is not only effective for this purpose, but may also be applied to conventional integrated stationary devices. Furthermore, the examples shown in FIGS. 2 to 8 as measurement optical systems are merely examples of the present invention, and various modifications may be made from this example in order to configure the optical measurement section into a handy type. It is possible for a person skilled in the art to
A modified example of this is shown in the figure using an example of a four-point spot pattern. FIG. 16 shows the measuring optical system at 8 degrees, FIG. 17 shows the measuring light projecting optical system, FIG. 18 shows the measuring light receiving optical system, and FIG. 19 shows the aiming optical system. The measurement light projection optical system 9' uses a half mirror 45 instead of a half prism, and runs along a straight optical axis a1 from the infrared light emitting diode projection light source 15' to the half mirror 45, and is aligned at a right angle at the half mirror 45. By positioning the eye E' to be examined on the optical axis of the measurement light reflected by , the measurement light can be projected into the eye E°. Above the optical axis between the light source 15'' and the half mirror 45, in order from the light Ft15° side, there are a collimator lens 19', a pyramid-shaped four-sided pyramidal prism 46, an aperture of 47°, a light projection relay lens 21', 4 Hole mirror 48. Eyepiece 2
2° is placed. In order to form a four-point spot pattern, the four-sided pyramidal prism 46 directs infrared light from the light source 15° through the collimator lens 19° to the optical axis, and four beams that pass through positions at central angles of 90° around +. Separate into light beams. The diaphragm 47 is arranged at the focal point of the stepped light lacing 21', and the four light beams emitted from the quadrangular pyramidal prism 46 pass through the diaphragm 47 and then enter the light projection relay lens 21'', each with an optical axis a1. The four-hole mirror 48 is a mirror for reflecting at right angles the measurement light, which is the retinal reflected light, in the measurement light receiving optical system 10, which will be described later. , its upper reflective surface is inclined at 45° with respect to the optical axis, l, and a small hole is provided in the part corresponding to the optical path so as not to block the optical path of the projected spot pattern in the projecting optical system 9. Therefore, the measurement light that has passed through each of the four-hole mirrors 48 becomes a four-point spot pattern and enters the eyepiece 22', is reflected at a right angle by the half mirror 45, and enters the subject's eye E'. When the measurement light receiving optical system is set at 10°, the measurement light travels backward through the optical path of the light emitting optical system 9' from the eye E° to the 4-hole mirror 48, and then passes through the 4-hole mirror 48.
It is reflected at right angles by the hole mirror 48. A micromirror 49 having a reflective surface parallel to the four-hole mirror 48 is arranged on the optical axis al+ of this reflected light.
The measurement light is further reflected downward at right angles by these four micromirrors. Below the micromirror 49, an imaging lens 27'' and a light receiving sensor 29 are arranged along the optical axis a41.
’ is placed. In the aiming optical system 50, the corneal reflected light of the illumination light partially transmitted through the half mirror 45 or the tychroic mirror 31'
is reflected downward at a right angle by the monitor relay lens 33.
To pass through °. A first 45° mirror 51 is arranged below the monitor relay lens 33', and a transparent glass reticle plate 5 on which a reticle pattern is written on the reflected optical path.
2 is placed. This reticle plate 52 is arranged at a position conjugate with the eye E° with respect to the monitor relay lens 33°. A second 45° mirror 53 is disposed at a position past the first 45° mirror 51 and the reticle plate 52 so as to reflect the aiming light incident thereon downward at right angles. Below the second 45° mirror 53 is a micromirror 49 at 10° of the measurement light receiving optical system.
The following optical axis a4° is shared with this light receiving system 10',
They also share an imaging lens 27 and a light receiving sensor 29'. Therefore, this aiming optical system 50 is configured such that a monitoring reticle optical system is incorporated into a monitoring camera optical system. Note that in the aiming optical system 50, the micromirror 49 is extremely small and the illumination light passes through its peripheral portion, so its presence does not pose a problem. According to the configuration and operation of the embodiments and modified embodiments described above, for example, as shown in FIG. 1 in one hand and position it toward the subject's eye, with the subject looking at the 3rd to 5th optotype 38, and observing the posture of the optical measurement unit 1 while looking at the monitor 4. If the aim and focus are achieved while finely adjusting the position, the examiner only needs to capture that moment, and the rest is automatically calculated by the main unit 2, and the eye refraction is calculated. displayed on the monitor 4. The measurement time has been extremely shortened, and the optical measurement unit 1 can be adjusted to the position of the subject no matter what posture the examinee is in, making measurement easier for the examiner and easier for the examinee. frees you from the uncomfortable feeling of pain during measurement.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the schematic configuration of the eye refraction measuring device of this embodiment. FIG. 2 is a diagram showing a measuring optical system built into the optical measuring section in this embodiment. Figures 3 to 8 are diagrams showing each optical system as each element constituting the measurement optical system of this embodiment, where Figure 3 is the measurement light projecting optical system, and Figure 4 is the measurement light reception FIG. 5 shows an illumination optical system, FIGS. 6 and 7 show a monitor camera optical system and a monitor reticle optical system as aiming optical systems, and FIG. 8 shows a target optical system. Figure 9 and 1O
The figures are explanatory diagrams illustrating the aiming situation of the corneal reflected light due to the difference in the position of the illumination light source. FIG. 9 shows a state where the aim is off, and FIG. 10 shows a state where the aim is correct. FIG. 11 is a diagram showing the illumination light source and the weight attached to the disc member in this embodiment. FIG. 12 is a perspective view showing the optical path of the measuring light incident on the cornea through a fixed point on the front axis and reaching the retina in this embodiment. FIG. 13 is a diagram generalizing the position of the measurement light pattern projected onto the cornea in this embodiment on a coordinate plane, and FIG. 14 is a diagram showing the measurement light pattern projected onto the cornea as shown in FIG. 13. The position of the image on the light receiving sensor corresponding to the pattern is generalized and shown on a coordinate plane. 15th
The figure is a flowchart showing control of eye refraction measurement according to this embodiment. 16 is a diagram showing a measurement optical system of a modified embodiment, FIG. 17 is a diagram showing a measurement light projecting optical system in FIG. 16, and FIG. 18 is a diagram showing a measurement light receiving optical system in FIG. 16. , FIG. 19 is a diagram showing the aiming optical system in FIG. 16. FIG. 20 is a diagram showing the measurement state of the eye refractive power according to this embodiment. DESCRIPTION OF SYMBOLS 1... Optical measurement part, 2... Main body part, 3... Image recognition device as a part of control means, 4... Monitor, 5...
- Control circuit as part of the control means, 8... Measuring optical system, 9... Measuring light projecting optical system, 10... Measuring light receiving optical system, 11... Target optical system, 12...Monitor camera optical system as part of the monitor optical system, 13...
a monitoring reticle optical system as part of a monitoring optical system;
14...Illumination optical system, I5 ・Measurement) 1'4 light source for projecting light, 29 ・Light receiving sensor, 30 ~ illumination-゛addition, 35.
Reticle light source, 38 optotype, E-testing time limit Applicant: Ryusho Sangyo Co., Ltd. Agent
Figure 1 Figure 13 Figure 14 Figure 9 Figure 10 Figure I5 (f02) Figure 20

Claims (1)

[Claims] (1) In an eye refractive power measuring device equipped with a measuring optical system (8) for objectively measuring the eye refractive power of the eye to be examined (E), the measuring optical system (8) is , a plurality of lights arranged in a circumferential direction around the optical axis (a_2) of the measurement light set to be projected onto the eye (E) to be examined, at positions symmetrical to the optical axis (a_2). Point light source (30
); and means for monitoring the relative positional relationship between the position of the optical axis (a_2) of the set measurement light and the center position of the corneal reflection pattern of the plurality of point light sources (30). (4) A monitor optical system (12, 13) for displaying an eye refractive power.