JPH027935A - Apparatus for measuring eye refractivity - Google Patents

Abstract

PURPOSE:To rapidly perform measurement always in a definite state without missing measuring timing by automatically starting measurement at the point of time reaching not only a focus matching state but also a collimation matching state. CONSTITUTION:An eye refractivity measuring apparatus is equipped with an optical measuring part 1 having a measuring optical system for measuring eye refractivity objectively with respect to an eye to be examined and a main body part 2 for operationally processing the measured data from the optical measuring part 1 to calculate eye refractivity. The main body part 2 has an image confirmation device 3, a monitor 4, a control circuit 5, an operation switch 6 and a printer 7 and starts measurement due to the measuring optical system of the optical measuring part 1 when said measuring optical system becomes collimation and focus matching states with respect to the eye to be examined and also calculates the refractivity of the eye to be examined on the basis of the image signal from a light detection sensor.

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 reflexometers are known as devices for objectively measuring eye refraction. A refractometer is a device that objectively measures the refractive power of the eye by observing through an optical system whether a light source is correctly focused on the fundus of the eye, that is, the retina. In order to perform a measurement, as a preliminary step, it is necessary to adjust the positional relationship between the measuring optical system on the device side and the eye to be measured so that it is in a measurable state (aimed and in-focus state). As soon as the adjustments are completed, actual measurements will begin. Conventionally, the measurement start timing was determined by the operator turning on the measurement start switch when the operator judged that the adjustment was completed while making the adjustment. However, the operator often misses the timing to turn on the start switch, or the timing shifts, and the level of skill of the measurer is a factor that greatly influences the proper θ-setting timing and accurate measurement. Ta. Therefore, there is considerable variation in the time required for measurement and in the measurement results depending on the skill level of the measurer. Furthermore, there are various types of focus detection mechanisms for optical machines such as cameras, but it is well known that , there is no known mechanism for simultaneous detection with the alignment detection mechanism.

[Purpose of the invention]

The present invention has been devised in view of the problems of the prior art as described above and to effectively solve the problems. Therefore, the purpose of the present invention is to automatically start measurement by detecting both the in-focus state and the aiming state, and to quickly perform measurements under constant conditions without missing the measurement timing. The object of the present invention is to provide an eye refractive power measurement device that can perform the following steps.

[Means to solve the problem]

The eye refractive power measuring device according to the present invention solves the problems of the prior art as described above.1. , is structured as follows to achieve that purpose. That is, an optical measuring section equipped with a measurement optical system for objectively measuring the eye refractive power of the eye to be examined, and arithmetic processing of the measurement data signal from the optical measuring section to calculate the eye refractive power. It is equipped with a general section. The optical measuring section and the main body may be separate bodies, or may be integrated. The measuring optical system has the following optical systems as one of its constituent elements. ■
a measurement light projection optical system that projects measurement light and projects a projection pattern onto the fundus of the eye to be examined; A measurement light receiving optical system and ■ a corneal reflection pattern of an aiming light source placed at a symmetrical position with respect to the optical axis of the measurement light incident on the eye to be examined is received by the light receiving sensor. A aiming optical system that indicates the relative position to the eye to be examined. Further, the main body portion causes the measurement optical system to start measurement by the measurement light optical system when the measurement optical system is aimed at and in focus on the eye to be examined, and the measurement optical system starts measurement based on the image signal from the light receiving sensor. The apparatus includes a control means for calculating an eye refractive power for optometry.

[Effect]

In the eye refractive power measuring device according to the present invention, it is possible to detect whether or not the aim is correct based on the position of the image signal on the light receiving sensor based on the corneal reflection pattern of the aiming light source in the aiming optical system. In other words, since the cornea is approximately spherical, the position of the image signal on the light receiving sensor changes depending on the positional relationship between the aiming light source and the eye to be examined, and the aim is determined by calculating the position of this signal. It is possible to detect whether the state is For example, if the center position of the corneal reflection pattern on the light receiving sensor is set as the reference position when the sight is aligned,
It is possible to calculate in which direction and by how much the position of the corneal reflection pattern of the actual aiming light deviates from this reference position from the position of each element of the light receiving sensor ball, and the calculated data can be displayed on some display means. It is also possible to display the It is also possible to obtain a monitor image from an image signal on the light receiving sensor. Furthermore, with this aiming optical system, it is also possible to determine whether or not it is in focus by applying a well-known technique. Therefore, it is possible to determine whether or not to start actual eye refraction measurement based on the data obtained through arithmetic processing, and this determination is made by the control means. A command signal to start measurement is output to the system. Since this judgment and signal output are always performed instantaneously under constant conditions by an electronic mechanism, measurement timing is never missed and highly reliable measurement results can be obtained under constant conditions.

【effect】

As is clear from the above explanation, the present invention exhibits the following excellent effects. In other words, when objectively measuring the degree of eye refraction, the measurement is automatically started by detecting that both the in-focus state and the aiming state are in place, so the measurement can be performed quickly in a constant situation without missing the measurement timing. measurements can be made.

【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 built-in measurement optical system, 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 2, and an image recognition device 3 recognizes the contents of the signal, that is, the alignment of the aiming and focusing conditions, and the other side displays the image signal as an image. Each monitor 4 is built-in. Also, while exchanging signals with both the image recognition device 3 and the monitor 4, a control signal is output to the optical measurement section l, and the eye is measured based on the 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. In other words, when the measuring optical system is aimed at and in focus on the eye to be examined, this optical system starts measurement, and the eye refractive power is calculated based on the image signal from the optical measuring section l. The means is composed of an image recognition device 3 and a control circuit 5. In the figure, 6 is an operation switch for the control circuit 5, and 7 is a printout of the result calculated by the control circuit 5. The optical measurement section 1 and the main body section 2 may be connected by a cable (not shown) or wirelessly, and in any case, the optical measurement section 1 requires position adjustment with respect to the eye to be examined during measurement. Only part l is extracted and separated as a movement system so that it can be moved freely relative to the stationary main body part 2, so that the examiner can 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 each component of the measuring optical system 8. Elemental optical systems include a measurement light projecting optical system 9, a measurement light receiving optical system 10, a target optical system 11, a monitor camera optical system 12, and a monitor reticle optical system 1.
Aiming optical system consisting of 3, and 1: illumination optical system for monitor 1
Each elemental optical system of 4 is shown in a separate table (7). First, Figure 3 shows the measurement light projecting optical system 9.
An infrared light source is used as the n11 constant light projecting light source 15, and the measurement light projected from the light source 15 passes through the first reflecting mirror 1.
6 and reflected upward at right angles. On the optical axis aI of the measuring light reflected in two directions at right angles, the surfaces forming the right-angled opposite sides of the two right-angle prisms are the first reflection for the light IMJl, and 45 A first prism 17 that is joined at an angle is arranged. This first prism 17 is a half prism, and infrared light is partially reflected at a certain ratio and the rest is transmitted, while most visible light is transmitted. Therefore, by positioning the eye E to be examined 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 collimator lenses 19 . Light projection pattern mask 20. A light emitting relay lens 21 is arranged, and a first reflecting mirror 16 and a first prism 1
An eyepiece lens 22 is placed on the optical fithal between the eyepiece 7 and the eyepiece 7. The measurement light is emitted from the light emitting light source 15 and passed through the Koritsuta lens 19 . Light projection pattern mask 20. Emitter relay lens 2
1. First reflective mirror 16. Eyepiece 22. The light enters the eye E through the first brism 17, the pupil, the corneal surface, and the crystalline lens, and projects a light source of a projection pattern onto the retina. FIG. 4 shows a light receiving optical system lO for measuring light. The measurement light of the light receiving system becomes reflected light from the image of the light source formed on the retina of the eye E and travels backward along the light @a2+a' of the light projecting optical system 9. When the mirror 16 reaches the position (shown in FIG. 2), it passes through the first through hole 23 opened approximately at 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 through hole 2
The measurement light that has passed through 3 further passes through the aperture 24 and the second through hole 2.
Pass 6 and go straight. Therefore, the optical axis a6 of the light-receiving system measurement light traveling in the opposite direction to the optical axis a1, after passing through the first through hole 23, continues straight downward and reaches the light-receiving sensor 29 via the imaging lens 27 and the filter 28. FIG. 5 shows the monitor illumination optical system 14, which evenly surrounds the optical axis a 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. Note that this optical axis a. coincides with the optical axis a2 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 measurement unit 1 toward the eye E to be examined, and the monitoring camera optical system 12 is used as shown in FIG. Configure as shown. As shown in FIGS. 9 and 1O, this illumination light is projected so that a parallel light beam (beam) forming an appropriate inclination angle λ with respect to the optical axis a of the illumination optical system is directed toward the eye E. If the optical axis a of the eye E is shifted from the optical axis a5 of the illumination optical system, six images (approximately point The center position of the reflected image of the light source (that is, the optical axis am of the subject's eye E) causes a "shift" with respect to the optical axis a of the illumination optical system.
Aiming can be performed by measuring the amount ε of the deviation and setting it to 0. 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. That is, when in focus, this bright spot is the smallest and has the strongest contrast, so this state can be detected by the image recognition device 3.
As with the aiming ('!) operation, detection is performed by focusing on the same object, the corneal reflective bright spot, so both the aiming and focusing operations can be detected at a relatively high speed and can be processed immediately. By aiming like this,
The optical axis of the measurement system, monitor system, etc. can be aligned with the optical axis a1 of the eye E to enable measurement, and by focusing, the optical measurement unit ■ and the eye E can be aligned.
distance from the eyepiece lens 2 of the measurement light projection optical system 9.
2 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 a5 of the illumination optical system 14 (assuming the illumination direction is the front), there is a dichroic ink mirror 31 that reflects infrared rays and transmits visible light. , aiming light (
It is arranged at an angle of 45° with respect to the optical axis a so as to reflect the infrared rays downward at right angles. On the optical axis a6 bent downward at a right angle by the dichroic mirror 31, there is a half prism with characteristics roughly opposite to that of the first prism I7, that is, a half prism that transmits most of the infrared light and reflects most of the visible light. A second prism 32 is arranged. The aiming light is reflected by the dichroic mirror 31 and passes through the second prism 32 as it is.
The light travels straight downward along 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 (7, and reaches the second reflecting mirror 25 along the optical axis a). Therefore, to be more precise, they intersect within the second 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 a6. 7 shows the monitoring/ticle optical system 13. On the side of the second prism 32, there is a reticle light source 35.
+, Chikulba Koon Mask 36. Reticle objective lens 3
7 are provided in order, and the light irradiated from the reticle light source 35 is directed along the optical axis a to the reticle pattern mask 3.
6 becomes the sign pattern light,
It roughly passes through the reticle objective lens 37, reaches the second prism 32, and is refracted downward at a right angle. The reticle pattern is represented by, for example, a double circle with an aperture, the inner circle of which indicates the minimum measurable pupil diameter, and the outer circle drawn at the standard position where the corneal reflection image occurs. The prism surface of the second brism 32 is arranged so that the optical axis alo of the reticle light refracted downward at right angles by the second prism 32 coincides with the optical axis a8 of the L aiming light. Therefore, the optical system after that 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 match, if the center of the corneal reflected light of the illumination light 6@ is on the light @a5 of the illumination optical system, The center of this coincides with the center of the marker pattern of L = 9 barrels, and if this coincidence is detected by the m-light receiving units 29-L, it is possible to detect that the aim is correct. Become. In this embodiment, the reticle pattern is obtained by the square light source 35 and the reticle batten mask 36, but the reticle pattern only needs to be able to display the position as the aiming reference on the monitor image. Alternatively, a transparent glass plate that transmits infrared light may be placed at a position conjugate to the eye E with respect to the monitor relay lens 33 on the monitor camera optical system I2, and the pattern may be written on this. It is also possible to write a pattern and have the light receiving sensor 29 detect the pattern. In FIG. 8, the target optical system 11 is shown. Since the tichroic mirror 31 disposed on the optical axis ali passing through the first prism 17 transmits visible light, the light @a
If an object 38 is placed behind the dichroic mirror 31 on the extension of 5, the subject can see the object 38 through the first prism 17 and the dichroic mirror 31, By looking directly, the light @a□ of the eye E to be examined can be aligned approximately above the optical axis a. 1J, as mentioned above, the illumination light source 30 also serves as a light source for aiming light, and one light receiving sensor 29 is configured to detect aiming light including reticle light and measurement light. As a whole, the measuring optical system 8 itself has been miniaturized, and is extremely advantageous in configuring the optical measuring section l in a single-day type.Moreover, the moonlight source 30 is shown in FIG. Optometry window 39 as shown
A disc member 40 rotatable around the optical axis a is attached to the housing (not shown) of the optical measurement unit l, and 45 disc members 40 are disposed on the periphery of the optometry window 39 and are rotatable around the optical axis a. An illumination light source 30 is fixedly attached to this disk member 40. A weight 11'3 is attached to this disc member 40 at a location where the two illumination lights g30 are located on the horizontal reference radial line 42''-, and this makes the disc member 40 and, in turn, the illumination light source 30 can always maintain a constant posture regardless of the inclination of the optical measurement section I. Although such a structure may cause unnecessary "shaking" in the illumination light source 30, since the aiming operation is originally performed carefully and quietly, there is no problem in reality. 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. When the attitude of the optical measuring unit l is tilted with respect to the horizontal direction, the image recognition device 3 can obtain a seated image of the corneal reflection bright spot on the monitor caused by the illumination light source on the reference meridian 42, so which bright spot can be identified. Is it paired or horizontal (if horizontal is the standard)?
In order to know this, control is performed to turn on only the illumination light sources on the reference radius and turn off the other illumination light sources (the reverse control is also performed). This control operation only takes a moment, and the examiner does not notice any unsightliness such as the monitor screen becoming dark. In this way, the inclination angle of the optical measurement unit 1 with respect to the horizontal direction can be obtained, and the value of the axis angle (AXiS), which is one of the measurement calculation results, is corrected by subtracting that angle, thereby obtaining accurate information. The value is displayed in the output. The pattern 10 formed by the light projection pattern mask 20 of the measurement light projection optical system 9 may be of various types, for example, a circular pattern formed in an annular shape around the optical axis a2 and having a predetermined radius; Similar to the circular pattern, the pattern is spaced a predetermined distance from the center, for example, every 900, every 600, or 45
A spot pattern arranged at equal central angle positions, such as every degree, is realistic. Light emitting/receiving optical system 9 for measuring light in the ocular refraction dust measuring device of this embodiment configured as described above. Measurement of ocular refraction dust by lO is performed as follows. FIG. 12 is a perspective view showing the optical path in which the measurement light passes through a fixed point O on the optical axis a2, enters the cornea, and reaches the retina in this embodiment. In the measurement light projecting optical system 9 that is aimed and in focus, its optical axis a2 coincides with the optical axis a of the eye to be examined on two axes in the figure, and the measurement light is directed along the optical axis a2. The light passes through the fixed point 0 above, enters a point P on the cornea, and reaches a point Q on the retina. Note that this fixed point O is determined when the eyepiece lens 22 is located at a position where the position of the aperture 24 and the position of the corneal surface are conjugate with each other in the measurement light receiving optical system IO.
The measurement light projected from the measurement light light source 15 is transmitted to the eyepiece 2.
This is the point that passes on the optical axis a2 after two passes. Let the optical axis a, the distance between the upper retina and the cornea be d, and the distance between the cornea and the fixed point 0 be dl. The distance from the optical axis aE to the point P on the cornea is hl. Let θ be the inclination of the direction from the optical axis a1 to the point P with respect to the X-axis direction. Further, it is assumed that the long axis f of the refractive power of the eye to be examined lies in a direction tilted by - with respect to the X-axis. The short axis r2 is perpendicular to the long axis f1. The component in the long sleeve direction of this point P is P
11+If the component in the minor axis direction is PI3, then P + + = h + cos (θ-u)
(1) P +g=h+5in(θ-1)
It can be expressed as (2). Similarly, regarding the image (point Q) that receives refractive power from this corneal surface and is projected onto the retina, f is the distance from the optical axis a.
Each component QIIIQ11 in the 1 direction and the f2 direction can be expressed as follows. If the eye refraction dust in the horizontal direction is the eye refraction dust in the vertical direction, then the short axis f2 is perpendicular to the long axis r. And this h-tori. The relationship is expressed by equation (9). holds true. On the other hand, if the image of the light projection pattern projected onto the retina is viewed from the measurement light receiving optical system 1O, the light of the light receiving system is selected by the aperture 24 arranged in 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. Further, the position of the bar 24 is also the focal point position of the imaging lens 27, and the image light that passes through the aperture 24 and enters the imaging lens 27 travels parallel to the optical axis and hits the light receiving sensor 29. From the 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. In addition, as assumed in the light receiving system, the long axis f of the refractive power of the subject's eye is tilted by - with respect to the X axis. It is a fixed constant. From the above assumptions, Qll and Q1□ in the light receiving system are (lO) and (11)
Further, by substituting the relationship of equation (9) into each of these equations, it is represented by equations (12) and (13). Q++=hcos(φ-1)(10) Q12=h5in(φ-td)
(11) Here, from equations (7) and (12), and equations (8) and (13), the relationships of equations (14) 2 and () 5 are established. Perform operations such as transposition and expansion in equations (14) and (15) to obtain h(, coSφ−5X, hosir+ψ−
When Sx and Sy are determined as sy, equations (16) 2 and (17) are obtained. Sx sy (16)2 and (17), J] and C[・hl(1/
di-f)+)=A. When replaced with L'1l(1/dl-D2)-B, 5x=
Acos(θ-I)cos%-Bsin(θ-4)s
in〆--rls) Sy=Acos(θ-1) sin l +f35in(
It is simply expressed as θ−〆)cosd. In equations (18) 2 and (19), there are three unknowns to be measured, Hough B and I, and two values θ1. 7'L for θ2 SX
I+SY++Sx2. These unknowns can be found theoretically from the four equations that give SYz. In addition, as a correction value for refractive error, the spherical power (Sl
)H), cylindrical power (CYL), and axis angle (AXIS) are used, SPl+=D,, CYL=D=D,, AX
Please indicate each in IS-Me. Here, the light projection pattern is, for example, the optical axis a h of the eye E to be examined.
A total of 4 points of spora [・butter/ and '4 Otsu] face each other across the light @a g along the two meridians of the pupil passing through '. And this 2
The radius line is 2 (Y line) in the horizontal direction and the vertical direction, θ,
If = 0', 1 SXl"5XOI SV+"Sl10
When sθ2=90', S X2=F)K9 + S
V2=S)'! and solving the four equations described above, A=i/2(Sxo+Syy”;((Sxo-3ys)
2+4Sy%l:l (2[),)B = l/2・
C3xa+Sys J ((Sxo 5ys)'4Sy
3, "l) ('21)" is obtained. Accordingly, two points P on the X-axis Uemura J" and the y-axis are projected onto the cornea using the spont pattern as shown in Figures 1-3. . , P, and -C, the coordinates of the point '304 S% of the image formed on the light receiving sensor 29 as shown in FIG.
By measuring sxo, 5yo)s and (Sxt, 5Vs) with the image recognition device 3, the eye refractive power of the eye to be examined can be objectively known. Hereinafter, FIG. 15 shows a measurement-7Ll-chart using the eye refraction measuring device of this embodiment [7]. Each step will be explained in order. First, in the spray knob 100, the illumination light w 30 and the reticle light source 35 are turned on as a preparation mode 11, the light source 15 for projecting the measurement light is turned off, and the process moves to step +01 (4), and step +00 Step 100
In step 100', only the thermoluminescent light source 30 is turned on, and the reticle light source 35 and the projecting light source 15 are turned off and input to the monitor image. , - In the monitor image when the subject's eye E is present in front of the illumination light source 30, a group of bright spots and a reticle pattern due to the corneal reflection of the illumination light appear, and when the subject's eye E is not present, a reticle pattern appears. only appears. At Snap +01, it is determined whether Zorin Tough's switch/chi is on or not, and if O; is selected, step 10 is executed.
After outputting from the printer 7 in step 2, the process moves to step +03, 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 source 30. If it does, step 101
-1 transition, but if there is no [step +00-reverse 17, each step up to step 103 is repeated again. This judgment is based on whether the corneal reflected light of the illumination light is
This can be determined based on whether or not it can be detected, and the examiner can also determine this from the monitor image. In step 104, as a thermal detection mode, the image recognition device 3
), and proceed to step 105.\\. In step 105, the X coordinate (
It is determined whether the absolute value IXaI of If so, the process returns to step 100 and the steps up to step 105 are repeated again. In step 106, the y coordinate (
It is determined whether or not the absolute value 1y0] of yo) is smaller than the value of the y-axis deviation standard set as the allowable range of "deviation" in the y-axis direction, and if it is smaller, step! If the value is not smaller, the process returns to step 100 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 an example of a method that can be realized only by software, but in a more general way, including methods using hardware, bright spot detection is possible. The in-focus state may be detected by detecting the contrast state of the group. In step 108, it is determined whether or not the high frequency component (H7) obtained in step 107 is larger than the contrast reference value set as the allowable range of the in-focus state. 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 above appear on the monitor image in the form of positional deviation between the reticle pattern and the bright spot group and the strength and weakness of the contrast of the bright spot group, and the examiner can You can get an idea of how to adjust the aiming and focusing conditions. In step 109, as an angle correction mode, only the illumination light sources corresponding to the two bright spots on the reference meridian 42 are turned on among the bright spot group due to the corneal reflected light of the illumination light, and the other illumination light sources and the tArs constant light source 15 are turned on. and the reticle light source 35 is turned off and input to the monitor image in step 110.
Move to. 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 Ill. In step ill, a state in which the illumination light source 30 and reticle light source 35 are turned off and the measurement light projection 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 pattern of the fundus detected by the light receiving sensor 29 by the measurement light receiving optical system 1O appears on the monitor for a moment.
Since the measurement is completed at this point, the process immediately moves to step +12 for each light source, and the state is set to be the same as the preparation mode in which the measurement light source 15 is turned off and the illumination light source 30 and reticle light source 35 are turned on. Ru. 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 input 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 sufficient level for measurement, so this is checked in this step. If the signal level is high enough in step 113, the process moves to step +14 to enter the calculation mode, and if it is insufficient, the process moves to step 120 to perform error handling. As an error process in step 120, for example, a message such as "no target" may be displayed on the monitor screen in step 116, which will be described later. In step 114, the measurement data is input into the calculation formula stored in advance in the control circuit 5, and based on this, the spherical power (SPI(), cylindrical power (CYl, , axis angle (AX
IS) is calculated. The calculation formula for each element is not uniform because the measurement points differ depending on the projection butter 7, but as a relatively simple example, when projecting a total of four spot patterns with a center angle of 90 degrees, each spot Let the X and y coordinates of (Sxo), (Sxs), and (S
x+ a), (sxz7), (syo), (sys). (Sy+a) and (Syzy), and the spherical power (SPH), cylindrical power (CYL), and axial angle (AXIS) are determined by the following calculations. When the above calculations are completed, the process moves to step +15. In step 115, each element SP obtained in step 114)! , CYL, and AXIS are determined to be within a reasonable numerical range. If they are within a reasonable range, proceed to the appropriate next step +16; if outside the reasonable range, proceed to step 121. error handling is performed. As the error handling at step +21, for example, a message such as "try again" may be displayed on the monitor screen at step 116, which will be described later. A display resulting from the processing is displayed on the monitor screen.It should be noted 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. It is also possible to set the distance between the spectacle lens and the cornea (0 in the case of a VD value contact lens). When step 116 is completed, the process returns to the preparation mode of step +00. In addition, in the above-mentioned embodiment, the case where a four-point spot pattern is used as the light projection pattern has been explained, or as another spot pattern, an n-point spot pattern is projected onto each of the zero rays centered on the optical axis. By using the spot pattern and performing statistical calculations on each point, A, B, I and spherical power (SP
H), cylindrical power (CYL), and axial angle (AXIS) are determined, and in this case, the measurement accuracy can be dramatically increased by setting n to a large value. In addition, 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 onto the retina is expressed by an ellipse formula, and The horizontal eye refractive dust D1 and the vertical eye refractive dust D2 can be easily determined from the respective lengths of the long and short axes of the ellipse, and the inclination angle (axis angle) of the long axis is also determined based on the length of the light receiving sensor. It can be easily determined from the coordinates. Regarding the measurement method for calculating the eye refraction dust using the measurement optical system and light projection pattern as described above, it can only be used in a measurement device in which the optical measurement part and the main body part are separated as in the present invention. It goes without saying that this method is not effective for use in 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 projecting optical system 9' uses a half mirror 45 instead of a half prism, and has a straight optical axis from the infrared light emitting diode projecting light source 15'' to the half mirror 45, along the + direction. By positioning the eye E'' to be examined on the optical axis of the measurement light reflected at right angles, the measurement light can be projected into the eye E'. On the optical axis a1' between the light source 15' and the half mirror 45, collimator lenses 19' are arranged in order from the light source 15' side.
, pyramid-shaped four-sided pyramidal prism 46. Aperture 47°, floodlight relay lens 21', 4-hole mirror 48. Eyepiece lens 2
2' is located. In order to form a four-point spot pattern, the four-sided pyramidal prism 46 converts the infrared light from the light source 15' through the collimator lens 19° into four beams that pass through positions at central angles of 90° around the optical axis l. Separate into light beams. The diaphragm 47 is arranged at the focal point of the light projection relay lens 21', and the four light beams emitted from the quadrangular pyramidal prism 46 enter the light projection relay lens 21' after passing through the diaphragm 47, and each light beam is aligned with the optical axis. a, ″ to form a four-point spot pattern.The four-hole mirror 48 is a mirror for reflecting measurement light, which is retinal reflected light, at right angles in the measurement light receiving optical system lO″, which will be described later. The upper reflective surface is inclined at 45 degrees with respect to the optical axis a1, and in order to avoid blocking the optical path of the projected spot pattern in the projecting optical system 9', a small A hole is formed. Therefore, the measurement light I passes through the large diameter of the four-hole mirror 48 and enters the eyepiece 22° in a four-point spot pattern, is reflected at a right angle by the half mirror 45, and enters the eye E'. In the measuring light receiving optical system lO°, the measuring light travels backward through the optical path of the light projecting optical system 9″ from the eye E° to the four-hole mirror 48, and
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 all of this reflected light.
The measurement light is further reflected downward at right angles by this micromirror 49. An imaging lens 27' and a light receiving sensor 29 are disposed below the micromirror 49 along the optical axis a4''.
In the aiming optical system 50, the corneal reflected light of the illumination light that has partially transmitted through the half mirror 45 is reflected downward at a right angle by the guichroic mirror 3F, and is reflected downward at a right angle to the monitor relay lens 33'.
pass through. A first lens is located below the monitor relay lens 33'.
A 45° mirror 5I is arranged, and a transparent glass reticle plate 52 on which a reticle pattern is written is arranged on the reflected optical path. This reticle plate 52 is arranged at a position conjugate with the eye E' with respect to the monitor relay lens 33°. From the first 45° mirror 51 to the reticle plate 5
A second 45° mirror 53 is disposed at a position passing through the second 45° mirror 53 so as to reflect the aiming light incident thereon downward at right angles. Below the second 45° mirror 53, an optical axis a41 below the micromirror 49 in the measuring light receiving optical system 10' is shared with this light receiving system lO'', and an imaging lens 27° and a light receiving sensor 29' Therefore, this aiming optical system 50 is configured such that a monitor reticle optical system is incorporated into a monitor camera optical system.
9 is extremely small and the aiming light passes through its periphery, 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. Hold only the l in one hand and position it facing the subject's eye, with the subject looking at the optotype 38 3 to 5+n ahead, and look at the optical measurement part l while looking at the monitor 4.
If the aim and focus are achieved while making fine adjustments to the posture and position of the eye, the examiner only has to capture that moment, and the rest is automatically calculated in the main unit 2, and the eye refractive power is determined. is calculated and displayed on the monitor 4. Therefore, the measurement time is extremely shortened, and no matter what posture the subject is in, the optical measurement unit l can be adjusted to the condition.
Measurement becomes easier for the examiner, and the subject is freed 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. 1θ shows a state where the aim is correct. FIG. 11 is a diagram showing a state in which the illumination light source and the weight are attached to the disk member in this embodiment. FIG. 12 is a perspective view illustrating the optical path in which the measurement light passes through a fixed point on the optical axis, enters the cornea, and reaches 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 shows the constant control of the eye refractive power according to Example 1.
This is a diagram. 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. l... Optical measuring section, 2... Main body, 3... Image recognition device as part of control means, 4... Monitor, 5...
...Control circuit as part of control means, 8.Measurement optical system, 9.Measurement light projection optical system,! 0... Measuring light receiving optical system, 11... Target optical system, 12... Monitoring camera optical system as part of aiming optical system, 13...
Monitoring reticle optics as part of aiming optics, 1
4 illumination optical system, 15... light source for projecting measurement light, 29.
Light receiving sensor, 30...Illumination light source, 35...Reticle light source, 38...Optotype, E...Testing time limit Applicant: Ryusho Sangyo Co., Ltd. Agent: Patent attorney
Previous figure: 1st person, 1st figure, 2nd figure, 13th figure, 14th flash, 11th r? 1 Figure 9 Figure 10 Figure 15 (season 2)

Claims (1)

[Claims] (1) an optical measurement unit (1) equipped with a measurement optical system (8) for objectively measuring the eye refraction of the eye to be examined; and measurement data from the optical measurement unit (1). The measurement optical system (8) includes a main body (2) that calculates the ocular refraction by processing signals, and the measurement optical system (8) projects a measurement light pattern onto the fundus of the eye to be examined. Light projection optical system (9)
, a measurement light receiving optical system (10) that receives the reflected light of the projection pattern image projected onto the fundus of the eye to be examined onto a light receiving sensor (29), and an optical axis ( a_
5) Aiming light source (30) placed at a symmetrical position with respect to
and an aiming optical system (12, 13) that indicates the relative position of the measuring optical system (8) and the eye to be examined by receiving the corneal reflection pattern of the eye on the light receiving sensor (29); In (2), the measurement optical system (8) aims and focuses on the subject's eye to start measurement by the measurement light optical system (9, 10), and the light receiving sensor (29) ) An eye refractive power measuring device characterized by comprising a control means (3, 5) for calculating the eye refractive power of the eye to be examined based on an image signal from the image signal.