JPH0315449B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention measures a distance refractive power or a near refractive power by aiming a refractive power test optotype placed at a predetermined position at a subject through a corrective optical system. This invention relates to a distance and near refraction measuring device.

Conventionally, in consideration of the fact that the distance between the pupils of humans varies widely, a configuration has been constructed in which the interval of the measurement light flux passing through the corrective optical system can be changed according to the interval between both eyes to be examined. Various subjective refractometers are known that measure distance and near refractive powers while receiving responses.

One of them is to arrange various corrective lenses with different refractive powers at predetermined intervals on the outer periphery of a rotating disk, and to install a pair of rotating disks in front of both eyes so that they can be adjusted according to the distance between the pupils. There is an apparatus configured to select a corrective lens according to the refractive power of the eye to be examined and to have the examinee collimate a refractive power test optotype through an observation hole. However, in such conventional devices, the main body of the device is placed in front of the subject's eyes, and collimation of the optotype is performed through the viewing hole, so it is affected by the inner wall of the viewing hole, resulting in a state of so-called mechanical myopia. The disadvantage was that it was impossible to obtain accurate measurement values. In addition, with such conventional devices, each time the refractive power of the corrective lens is changed, the subject's visual field is temporarily blocked, which may cause psychological turmoil to some subjects, which may make it difficult to obtain accurate measurement values. There was a drawback that there was no.

In addition, as another conventional device, instead of placing a corrective lens directly in front of the eyes, for example, a projected image of the corrective lens is formed at the position where the glasses are worn, as if the corrective lens were present, and a visual target is collimated through this projected image. It is known that the camera is constructed so as to avoid blocking the field of view. However, with the device configured in this way, there is no particular problem when measuring refraction for distance vision because the two light beams from the optotype reach both eyes in parallel, but when measuring refraction for near vision, there is no particular problem. In order to obtain a state of natural near vision, it is naturally impossible to create a so-called convergence state in which the visual axes of both eyes intersect on the optotype image at the near measurement distance. Therefore, in such conventional devices, the refractive power of the correction lens is increased to match the distance of the optotype image with the near measurement distance, and a deflection prism corresponding to the near measurement distance is inserted in front of the eyes. The visual axes are made to intersect at certain positions. However, when measuring distance refraction, the trouble of inserting an unnecessary deflection prism into the optical path each time near refraction measurement is a factor that hinders the improvement of measurement efficiency. The distance between the retinas changes, causing a shift in the image on the retina, which impairs so-called fusion, resulting in the disadvantage that proper near refraction measurement cannot be performed.

The present invention has been made to eliminate these conventional drawbacks, and it is necessary to place optical members such as corrective lenses and deflection prisms in front of the eyes in both distance and near refraction measurements. It is an object of the present invention to provide a distance and near refraction measuring device that eliminates the need for distance refraction measurement and that can perform correction corresponding to changes in interpupillary distance even when transitioning from distance refraction measurement to near refraction measurement. do.

Hereinafter, before describing the embodiments of the present invention in detail, the principles of distance refraction measurement and near refraction measurement according to the present invention will be explained based on FIG.

First, in the case of distance refraction measurement, the optotype position for refractive power test (arrow A) is set at a sufficiently far position in front of the eyes E ₁ and E ₂ to be examined, so that both eyes E 1 and E ₂ are separated from the optotype.
The principal rays D ₁ and D ₂ of the two light beams reaching E ₂ are parallel to each other. Image of the corrective lens at this time (solid line
It is shown as x ₁ and x ₂ . ) is the position where glasses are worn in front of the eyes.
It is formed at P ₁ and P ₂ . In this way, an appropriate corrective refractive power value can be obtained by changing the images x ₁ and x ₂ of the corrective lens according to the refractive power in response to the response of the subject.

Next, in the case of near refraction measurement, the refractive power test optotype position (arrow B) is set to the corneal apex position M ₁ of the eyes E ₁ , E ₂ ,
Since it is set at a distance L ₀ forward from M ₂ , the principal rays G ₁ and G ₂ of the two light fluxes from the optotype
intersect with the aforementioned chief rays D ₁ and D ₂ at an angle φ. Therefore, the eye to be examined
The visual axes of E ₁ and E ₂ move toward each other, and the distance _L between the corneal apex positions M ₁ and M ₂ is the distance between the principal rays D ₁ and D ₂ during distance refraction measurement, that is, the pupil at that time. The distance between them will be shorter than the distance P _L. In this case, the image formation position of the corrective lens in front of the eye does not change unless the corrective lens is operated in any way, so the center O ₁ , O ₂ of the corrective lens and the direction of the visual axis in the far vision state, that is, the principal rays D ₁ , D ₂ Intervals Δ ₁ and Δ ₂ are respectively generated between them. In such a state, the optotype image will no longer be formed on the fundus of both eyes E ₁ and E ₂ to be examined due to the prism effect of the lens, and there is a possibility that proper near refraction measurement cannot be performed.

To solve this situation, the images of each corrective lens are moved in the direction shown by the broken lines y ₁ and y ₂ to approach each other, and the centers ₁ and ₂ of the new images y ₁ and y ₂ are used for near refraction measurement. What is necessary is to set the visual axis of the eye to be examined in . In other words, the optical axis of each corrective lens is adjusted for each eye according to the amount of movement of each eye E ₁ and E ₂ .
It is sufficient to move them closer to each other in the direction of the line connecting the centers of the pupils of E ₁ and E ₂ . Note that the amount of adjustment Δ required to move the image of the corrective lens corresponds to the intervals Δ ₁ and Δ ₂ mentioned above, but if we assume that Δ ₁ = Δ ₂ = Δ, which appears symmetrically, then by calculation of elementary analytic geometry, The adjustment amount Δ is determined by the following formula. That is, from the relationship Δ/L _f +1/2E _L =1/2P _L /L ₀ +1/2E _L , Δ=P _L (L _f +E _L /2)/2L ₀ +E _L is obtained.

Here, P _L is the interpupillary distance in the far vision state as described above, L _f is the distance from the corneal vertices M ₁ and M ₂ of the eye to be examined to the centers ₁ and ₂ of the corrective lens, and E _L is the distance between the eyes E _{1 and 2} of the corrective lens. , E ₂ and L ₀ indicate the near refraction measurement distance, respectively.

The value of this adjustment amount Δ is calculated by a processing system such as a control calculation circuit, which will be described later. However, the interpupillary distance P _L , which is the data necessary for calculating this Δ, will be described later when measuring distance refraction. This is obtained by detecting the amount of movement of a pair of aiming plates that make up the aiming system. A moving motor (described later) is connected to the corrective lens based on the value of the adjustment amount Δ calculated in this way.
control.

Next, a subjective refractometer to which the present invention is applied based on the above principle will be described with reference to the drawings.

As shown in Figure 2, the device of the present invention
Measurement optical system S for measuring the refractive power of E ₁ and E ₂
and an index projection system H for projecting an index for setting the positional relationship of the eyes E ₁ , E ₂ to the measurement optical system S onto the eyes E ₁ , E ₂ to be examined, and for aiming the eyes E ₁ , E ₂ to be examined. It is roughly composed of the aiming system J. Note that the subscripts 1 and 2 attached to the reference numerals below refer to the right eye and the left eye, respectively, except for the explanation of the arrangement interval of the optical system shown in FIGS. 3 and 4.

First, the measurement optical system S will be explained in detail. Light from a light source 1 illuminates a refractive power test optotype 4 provided on a rotating disk 3 via a condenser lens 2. There are various kinds of optotypes 4 for detecting spherical power, cylindrical power, cylindrical axis, etc., and these are selected by rotation of the rotating disk 3 and inserted into the optical path. In addition,
The light source 1, the condensing lens 2, and the rotating disk 3 are movable along the optical axis for near refraction measurement, which will be described later. Further, the light beam from the optotype 4 passes through a first projection lens 5 to a pair of corrective optics K ₁ and K ₂ provided behind this lens 5 for correcting spherical power, cylindrical power, cylindrical axis, etc. pass through. The corrective optical systems K ₁ and K ₂ are arranged at symmetrical positions on both sides of the optical axis of the first projection lens 5, and have the same optical configuration.

The details of the corrective optical systems K ₁ and K ₂ will be explained below using the corrective optical system K ₁ for right eye measurement as an example. The corrective optical system K ₁ includes a first group lens system 6 ₁ , a second group lens system 7 ₁ , Third group lens system 8 ₁ First and second cylindrical lenses 9 ₁ , 9 ₁ and deflection prisms 10 ₁ , 10 ₁ , 11
₁ and 11 ₁ , and the spherical power can be corrected by moving the first lens group 6 ₁ along the optical axis. Here, the third lens group 8 ₁ is 2
It consists of two lens systems, and cylindricity can be corrected by first and second cylindrical lenses 9 ₁ and 9 ₁ sandwiched between these two lens systems. These two cylindrical lenses 9 ₁ and 9 ₁ are cylindrical lenses with equal absolute values and opposite signs, and are rotatable around the optical axis, so that both lenses 9 ₁ and 9 ₁ can be rotated around the optical axis. Rotation in the same direction by the same angle corrects the cylindrical axis, and rotation in opposite directions by the same angle corrects the cylindrical power. On the other hand, the two deflection prisms 10 ₁ , 10 ₁ arranged behind the third group lens system 8 ₁ have a deflection amount that is symmetrical with respect to the vertical axis perpendicular to the optical axis, and these deflection prisms 10 ₁ , 10 ₁ around the optical axis in opposite directions and at the same angle, the horizontal prism value of the eye E ₁ to be examined can be corrected to perform so-called skew correction. Furthermore, the deflection prisms 11 ₁ , 11 ₁ arranged behind the deflection prisms 10 ₁ , 10 ₁ are optically rotated by 90° with respect to the deflection prisms 10 ₁ , 10 ₁ . The vertical prism value of the eye _E1 to be examined is obtained by rotation in the same direction and angle. In this way, the corrective optical system K ₁ for right eye measurement has spherical power, cylindrical power, cylindrical axis,
Although it is configured to be able to independently correct the refractive state such as the prism value, the corrective optical system for left eye measurement
Since K ₂ can be explained in the same way, the details will be omitted.
Note that each of the corrective optical systems K ₁ and K ₂ is movable in parallel to the horizontal direction across the optical axis of the first projection lens 5 in order to match the interpupillary distance of the eyes E ₁ and E ₂ to be examined.

In this way, each light beam that has passed through the pair of correction optical systems K ₁ and K ₂ is transferred to the second projection lens 12 and the half mirror 1.
3, third projection lens 14, and half mirror 1
5 to the eyes E ₁ and E ₂ to be examined, and pass through the pupils of the eyes to form an image of the optotype 4 on both funduses. In addition, the light beams that have passed through each of the corrective optical systems K ₁ and K ₂ are commonly relayed by a relay lens system R that includes a second projection lens 12 and a third projection lens 14, and are transmitted to the glasses of both eyes E ₁ and E ₂ to be examined. The images of the corrective optical systems K ₁ and K ₂ are formed at the wearing positions P ₁ and P ₂ (approximately 12 mm from the front of the eyes). In addition, when measuring the corrective refractive power for contact lenses, the eye to be examined E ₁ ,
Correcting optical system K ₁ , K ₂ for corneal apex position M ₁ , M ₂ at E ₂
Set to the position where the image is formed. Therefore, it is equivalent to the correction optical systems K ₁ and K ₂ being placed in front of the eyes, and the subject collimates the image of the optotype 4 through the half mirror 15 in a state of natural vision. can do.

In this way, the subject responds to the examiner while looking directly at the optotype 4 in a state of natural vision, performs correction using the correction optical systems K ₁ and K ₂ until the optotype 4 appears properly, and adjusts the correction value to the corrected value. The refractive power is now measured based on the

Next, the arrangement of the measurement optical system S and the state of the light flux will be explained in detail with reference to the schematic diagrams shown in FIGS. 3a, b and 4a, b. In each figure, the same reference numerals are given to the same components as in Figures 1 and 2, and each lens system is a thin lens whose front principal point position and rear principal point position coincide for the sake of simplicity. It is expressed as Note that the positions of the eyes E ₁ and E ₂ to be examined will be explained below only in the case where corrective refractive power for eyeglass lenses is measured.

Figures 3a and 3b show the arrangement of the optical system during distance refraction measurement, and to explain an example of the optical data, the focal length f ₁ of the first projection lens 5 is 250 mm;
The focal length f ₂ of the second projection lens 12 is 150 mm;
The focal length f ₃ of the projection lens 14 is the same as that of the second projection lens 1
It is 150mm like the second one. Further, the distance l ₁ between the optotype 4 and the first projection lens 5 is 250 mm, and the distance l 2 between the first projection lens 5 and the correction optical systems K ₁ and K ₂ is 250 mm _.
mm, the distance l ₃ between the corrective optical systems K ₁ and K ₂ and the second projection lens 12 is 100 mm, and the distance l ₄ between the second projection lens 12 and the third projection lens 14 is 300 mm. moreover,
The distance l ₅ between the third projection lens 14 and _{the eyeglass wearing positions P 1 and} P _{2 of the eyes E 1 and E 2 to} be examined is 200 mm, and the corneal position of the eyes to be examined is
The distance l ₆ between M ₁ and M ₂ and the glasses wearing positions P ₁ and P ₂ is 12 mm.
It is.

A case in which the corrective optical systems K ₁ and K ₂ are set to have a spherical power of 0 diopter under such optical data will be described below with reference to FIG. 3a. The principal ray of the luminous flux from the optotype 4 enters the correction optical system K ₁ , K ₂ while being kept parallel to each other by the first projection lens 5 , and at an intermediate position between the second projection lens 12 and the third projection lens 14 . The light beams intersect on the optical axis, and then become two mutually parallel light beams by the third projection lens 14 and reach the eyes E ₁ and E ₂ to be examined. The distance between the centers of the two light beams projected onto the eyes E ₁ and E ₂ is determined by the correction optical system K ₁ , K ₂
It can be adjusted by moving between the optical axes. Further, the image of the optotype 4 is once formed at a point α on the optical axis, and then transmitted through the third projection lens 14 to the fundus positions β ₁ , β ₂ of the eyes E ₁ , E ₂ to be examined.
Each image is formed on the top. In this case, the spherical power of the subject is assumed to be 0 diopter.

The center points γ ₁ and γ ₂ of the corrective optical systems K ₁ and K ₂ are the points δ ₁ and δ 2 of the subject's glasses wearing positions P ₁ and P ₂ with respect to the second projection lens 12 and the third projection lens ₁₄ . They are set to have a conjugate relationship. For this setting, positioning adjustment of the measurement optical system S with respect to the subject is performed. This adjustment will be described later. By adjusting the settings, it is possible to create the same condition as if the corrective optical system were placed at the position where the subject wears glasses, even though the corrective optical system is not placed in front of the subject's eyes. Note that the corrective optical systems K ₁ and K ₂ have been explained as thin lens systems in which the front principal point position and the rear principal point position coincide, but in an actual thick lens system, the rear principal point position of the corrective optical system is Subject's glasses wearing position P ₁ , P ₂
is set to be conjugate with the points δ ₁ and δ ₂ .

Next, referring to Fig. 3b, this shows the luminous flux state when the spherical power of the corrective optical systems K ₁ and K ₂ is set to -10 dayopters, and other optical devices, the position of the subject, etc. It is similar to FIG. 3a.
Here, the corrective optical systems K ₁ and K ₂ are configured so that the positions of the rear principal points do not change even if the _spherical power is changed, and the positions of the _rear principal points do not change even if the _spherical power is _changed . The conjugate relationship is the same as in Figure 3a. Note that the image of the optotype 4 is located at a point ε ₁ , which is 100 mm in front of the subject's glasses-wearing position P ₁ , P ₂ .
After being imaged at ε ₂ , it is projected onto the subject with a spherical power of -10 diopters and is imaged at the fundus positions β ₁ and β ₂ .

Distance refraction measurement is performed in this way, but as mentioned above, the principal rays of the two beams projected onto both eyes of the examinee are always kept parallel, and the refraction measurement is performed while the examinee has natural distance vision. I can finish it.

Next, the optical device and the state of the light flux during near refraction measurement will be explained based on FIGS. 4a and 4b. When measuring near refraction, the optotype 4 is moved together with the light source 1 and the condenser lens 2 toward the first projection lens 5 and along the optical axis. For example, when measuring near refraction at 300 mm, the optotype 4 is and the first projection lens 5
₁ is set to move to 41.6mm. Other optical arrangements, the position of the subject, etc. are the same as in the case of distance refraction measurement.

FIG. 4a shows the luminous flux state when the corrective optical systems K ₁ and K ₂ are set to 0 dayopter, and FIG. 4b shows the luminous flux state when they are set to -10 dayopter. First, referring to FIG. 4a, the two principal rays of the luminous flux from the optotype 4
After intersecting at a point φ on the optical axis between the third projection lenses 14, it reaches the subject via the third projection lens 14 at the intersection angle, that is, the convergence angle θ. Note that the image of the optotype 4 is formed at a point φ on the optical axis. Further, a point ω in front of the point φ on the optical axis is a virtual image position formed by the third projection lens 14, and this point ω is set 300 mm in front of the subject's glasses wearing positions P ₁ and P ₂ . As a result, the subject is placed 300mm in front of the glasses-wearing positions P ₁ and P ₂ .
The convergence angle θ is the same as if visual target 4 was placed at
You can aim with near natural vision.

FIG. 4b shows the case where the corrective optical systems K ₁ and K ₂ are set to -10 dayopters, and the image of the optotype 4 is at a point t ₁ , which is 75 mm in front of the subject's glasses-wearing positions P ₁ and P ₂ . The image is formed at t ₂ . In this case as well, the angle formed by the principal rays of the two light beams reaching the eyes E ₁ and E ₂ , that is, the convergence angle θ, is the same as in the case of Fig. 4a, and the subject is in a proper convergence state, that is, near The optotype 4 can be collimated in the state of natural vision. In this example, the near refraction measurement distance was set to 300 mm, but by changing the amount of movement of the optotype 4, it is possible to measure near refraction at a desired distance, and an appropriate convergence state can be achieved at any measurement distance. can be created.

In this way, when performing near refraction measurement, collimation is possible by obtaining the appropriate convergence angle θ simply by moving the optotype 4 along the optical axis. It can be achieved in the state. Furthermore, in this embodiment, the positions of the corrective optical systems K ₁ and K ₂ (corresponding to the front principal point position when assumed as a thick lens system) are arranged 250 mm in front of the first projection lens 5. . Thereby, the viewing angle when collimating the optotype 4 on the rotating disk 3 is not affected by the position of the optotype. This means that the rotating disk 3
Rotation eliminates the need to select optotypes of different sizes, improving measurement efficiency. Note that similar effects can be obtained even if the first to third projection lenses in this embodiment are configured with concave mirrors.

Next, the subject eye position setting optical system I for setting the subject eyes E ₁ and E ₂ at appropriate positions will be described. This eye to be examined position setting optical system I has eyes to be examined E ₁ ,
A pair of index projection systems H for projecting the images of the indexes 18a ₁ and 18b ₁ toward E ₂ and one aiming optical system J for aiming at the anterior ocular segments of both eyes E ₁ and E ₂ to be examined. It is configured.

First, the index projection system H will be explained using a right eye projection system as an example with reference to FIGS. 2, 5, and 6. The light from the light source 16 ₁ illuminates the index plate 18 ₁ for detecting the working distance through the condenser lens 17 ₁ .
As shown in FIG. 6, the index plate 18 ₁ is provided with indexes 18a ₁ and 18b ₁ on the front and back surfaces, respectively. The images of these indices 18a ₁ and 18b ₁ are formed on the anterior segment of the eye E ₁ through the fourth projection lens 19 ₁ and the reflecting mirror 20 ₁ .
Note that the index plate 18a ₁ is used to set the working distance (distance between the measurement optical system S and the eyes E ₁ and E ₂ to be examined) when measuring the corrective refractive power with a normal eyeglass lens, and the index plate 18b ₁ is used for setting the working distance in the case of contact lenses. In addition, a filter 2 provided in front of the light source 16 ₁
1 ₁ transmits only near-infrared light, which is invisible light, and has the effect of preventing miosis during measurement of the subject. Further, the light beam from this index projection system illuminates the periphery of the anterior segment of the subject's eye. Note that the left-eye projection system has the same configuration as the right-eye projection system, so a description thereof will be omitted. As will be described later, the optical axes of the pair of target projection systems H are inclined with respect to the optical axes of the measurement optical system S and the aiming system J. Also, the point where the optical axis of the measurement optical system S intersects with the virtual line Va passing through the center of the fourth projection lens 19 ₁ and orthogonal to its optical axis, and the two indicators 18 of the indicator plate 18
When the point where the virtual line Vb connecting the centers of _{a 1} and 18b ₁ intersects with the optical axis of the measurement optical system S is aligned, the index 18
It is possible to obtain the optimum focus state of a ₁ and 18b ₁ , and to clearly observe and measure the image of the index 18a ₁ or 18b ₁ at M ₁ or Q ₁ , which will be described later. This matching point is point _F1 shown in FIG.

The principle of setting the working distance using the index projection system H will be explained below with reference to FIG. Note that unless otherwise specified, only the right eye projection system will be described. Point Q ₁ is a position conjugate with the rear principal point position of corrective optical system K ₁ in measurement optical system S, and when measuring the corrective refractive power of a subject for a normal eyeglass lens, this point Q ₁ is It is necessary to set the working distance so that the position matches the glasses wearing position _P1 . Therefore, when the eye to be examined E ₁ is positioned as described above, the eye to be examined is
The image of the index 18a ₁ is formed at the corneal apex M ₁ of E ₁ . Therefore, the examiner uses the sighting system J
The anterior segment of the subject's eye is aimed at, and the working distance is set so that the image of the index _18a1 coincides with the center of the pupil.

Next, a case will be described in which the corrected refractive power of the eye _E1 to be tested for contact lenses is measured. In this case, it is necessary to align the anterior segment of the eye E ₁ with the position of the point Q ₁ which is the imaging position of the corrective optical system K ₁ .
Therefore, the index 18b ₁ is placed at the position of the point Q ₁ on the subject's eye E ₁
When they match, the image of the index _18b1 is formed at the center of the anterior segment of the subject's eye. Therefore, when measuring the corrective refractive power for contact lenses, the examiner aims at the anterior segment of the subject's eye using the sighting system J, and sets the working distance so that the image of the index _18b1 coincides with the center of the pupil. .

Note that the indicators 18a ₁ and 18b ₁ are the projection lenses 19 ₁
It is arranged on the index plate 18 ₁ so that the focal position is shifted from the target eye E 1 , and when the working distance is set to a predetermined working distance, an image can be formed on the anterior segment of the eye E ₁ to be examined.

Next, the aiming system J will be explained. As shown in FIG. 1, the light beams from both anterior ocular segments of the eyes E ₁ and E ₂ to be examined illuminated with near-infrared light by the index projection system H pass through the half mirror 15 and the third projection lens 14 to the half mirror. 13 and reaches the aiming plates 23a, 23b by the imaging lens 22.
Anterior segment images of both eyes E ₁ and E ₂ to be examined are formed on 23b using near-infrared light. Since the third projection lens 14 and the imaging lens 22 are a telecentric optical system, the images of the anterior segments of the eyes E ₁ and E ₂ on the sighting plates 23a and 23b are obtained by changing the working distance. can also be observed without positional shift. Aiming plate 23
a, 23b have aiming indicators na, nb, and nc, respectively, as shown in FIGS. Correction optical system in system S
The distance movement between the optical axes of K ₁ and K ₂ , that is, the eye to be examined E ₁ ,
In conjunction with changing the distance between the centers of a pair of measurement light beams projected onto E ₂ , both anterior segment images of the eyes E ₁ and E ₂ formed with near-infrared light are adjusted to the indexes na, nb, and nc. These images are superimposed on the image, enter the image pickup tube 26 via the mirror 24 and the relay lens 25, are converted into video signals, and can be observed as visible images on the monitor television 27.

The procedure for positioning and setting the eyes E ₁ and E ₂ to be examined using the above-mentioned index projection system H and sighting system J will be explained with reference to FIG. 9. FIG. 9 schematically shows images displayed on the monitor television 27, where images A ₁ and A ₂ are images of the pupils of the eyes E ₁ and E ₂ to be examined, and images Ba ₁ and Ba ₂ are images of the indices 18a ₁ and 18b ₂ projected by the index projection system H onto the eyes E ₁ and E ₂ to be examined. Note that the images of the indicators 18b ₁ and 18b ₂ are omitted from illustration. Further, image , is an image of the indices na and nb formed on the aiming plate 23a, and is an image of the index nc formed on the aiming plate 23b. In the case of Fig. 9a, the distance between the optical axes of the corrective optical systems K ₁ and K ₂ , that is, the distance between the centers of the pair of measurement light beams projected onto the eyes E ₁ and E ₂ to be examined, matches the interpupillary distance of the examinee. In addition, the central optical axis of the measurement optical system S and the center of both eyes of the subject do not match, and the measurement optical system S and the subject's eyes do not match.
This indicates that the distance between E ₁ and E ₂ , that is, the working distance is not appropriate. Hereinafter, the adjustment procedure for transitioning from such an inappropriate setting state to a proper setting state will be explained, focusing on the case of measuring the corrective refractive power for a spectacle lens.

First, the refractometer body or the subject itself is adjusted by moving in the vertical direction so that the pupil images A ₁ and A ₂ of the eyes E ₁ and E ₂ to be inspected are sandwiched in the center of the index image. At this time, the subject is fixed to a subject holding section (not shown), and the position of the subject can be adjusted by moving this subject holding section. This adjustment completes the optical axis alignment in the vertical direction (see FIG. 9b).

Next, as shown in FIG. 9c, the index images Ba ₁ ,
The apparatus main body or the subject itself is moved along the measurement optical axis so that Ba ₂ is located at the center of the index image na, that is, coincides with the centers of the pupil images A ₁ and A ₂ .
This movement adjustment completes the setting of the working distance.

Next, as shown in FIG. 9d, the apparatus body or the subject is moved in the left-right direction so that the distance between the pupil image _A1 and the index image nb and the distance between the pupil image _A2 and the index image are made equal. . This adjustment completes the alignment of the central optical axis of the measurement optical system S and the centers of the eyes E ₁ and E ₂ in the left-right direction.

Next, as shown in FIG. 9e, the aiming plate 23a,
By moving 23b, the index image is moved and adjusted in the left and right direction, and the index image is placed at the center of the pupil images A ₁ and A ₂ .
Match nb,. Note that the aiming plates 23a, 2
As described above, the sight plates 23a and 23b move by equal amounts in opposite directions, and the movement of the sight plates 23a and 23b is linked to the movement of the optical axes of the corrective optical systems _K1 and _K2 . In this way, the distance between the optical axes of the corrective optical systems K ₁ and K ₂ can be made to match the interpupillary distance of the eyes E ₁ and E ₂ to be examined, and the optical axis of the measurement optical system S can be made to match the distance between the pupils of the eyes E ₁ and E ₂ to be examined. Axis alignment and working distance adjustment are completed.

Next, the drive mechanism of the corrective optical systems K ₁ and K ₂ will be explained based on FIG. 9. The corrective optical systems K ₁ and K ₂ are attached to the optical benches 30 ₁ and 30 ₂ and are movable within a plane including both optical axes so that the optical axes can be moved closer or farther apart. That is, the optical bench 30 ₁ ,
30 ₂ is a male threaded portion 34 of a connecting member 33 connected to a female threaded portion formed on a bracket 32 provided approximately at the center.
This connecting member 33 is connected to a moving motor 36 via a speed change gear 35. Here, the male threaded portion 34 of the connecting member 33 is divided into two halves with opposite threads, each of which is adapted to be screwed into the female threaded portion of the bracket 32 of the optical benches 30 ₁ and 30 ₂ . In addition, the optical bench 30
The bracket _{No. 2} and the state in which it is screwed together with the connecting member 33 are not shown.

Next, lens driving of the corrective optical systems K ₁ and K ₂ will be explained. Since both optical systems K ₁ and K ₂ have the same configuration, one optical system K ₁ will be explained as an example.
The first group lens system 6 ₁ is arranged at the front end of the lens barrel 37 ₁ , and a rack 38 ₁ extending in the optical axis direction is attached to the lens barrel 37 ₁ . This rack 38 ₁ is engaged with a pinion 39 ₁ , and this pinion 39 ₁ is pivotally supported by the motor 40 . This allows the first group lens system 6 ₁ to move along the optical axis. Further, one of the second lens group 7 ₁ and the third lens group 8 ₁ is arranged at a predetermined interval behind the first lens group 6 ₁ , and each lens system 7 ₁ ,
8 ₁ is fixed to the optical bench 30 ₁ . Further, a lens barrel 41 ₁ is provided behind the lens barrel 37 ₁ , and two cylindrical lenses 9 ₁ , 9 ₁ are arranged one behind the other in this lens barrel 41 ₁ . And one cylindrical lens 9
₁ is attached to a ring gear 42 ₁ , and this ring gear 42 ₁ is connected to a motor 44 via a drive gear 43 ₁ . Further, the other cylindrical lens 9 ₁ is attached to a ring gear 45 ₁ provided behind the ring gear 42 ₁ , and this ring gear 45 ₁ is connected to a motor 47 ₁ via a drive gear 46 ₁ . In this way, the cylindrical lenses 9 ₁ and 9 ₁ are rotatable around the optical axis.

Further, a lens barrel 48 ₁ is provided at the rear of the lens barrel 41 ₁ , the other of the third lens group 8 ₁ is fixed to the front end of this lens barrel 48 ₁ , and a horizontal deflection prism 10 is provided behind it. ₁ , 10 ₁ are arranged. and,
Crown gears 49 ₁ and 50 1 are attached to these deflection prisms 10 ₁ and 10 ₁ , respectively, and these crown gears 49 ₁ and 50 ₁ are connected to one pinion 51 _{1 .}
This pinion 51 ₁ is rotationally driven by a motor 52 ₁ . As a result, the deflection prism 10
₁ and 10 ₁ can be rotated by the same angle in opposite directions. Furthermore, the horizontal deflection prism 1
At the rear of 0 ₁ and 10 ₁ is a vertical deflection prism 1.
1 ₁ and 11 ₁ are arranged, and these deflection prisms 1
Crown gear 5 is attached to 1 ₁ and 11 ₁ as in the horizontal direction.
3 ₁ and 54 ₁ are respectively attached, and these crown gears 53 ₁ and 54 ₁ can be rotated in the same manner as in the horizontal direction by a motor 56 ₁ via a pinion 55 ₁ .

Note that support tubes 57 and 58 for guiding are attached to the front and rear of the optical benches _{30 1 and} 30 _{2 .}
horizontal movement is stable. In addition, a guide rod 5 is provided at the rear end of the optical benches 30 ₁ and 30 _{2 .}
The slide plates 62 ₁ , 62 ₂ are connected via _the arms 60 ₁ , 60 ₂ and the arms 60 ₁ , 60 ₂ .
60 ₂ is rotatable around rotation pins 61 ₁ and 61 ₂ , and the amount of horizontal movement of the optical axes of the correction optical systems K 1 and K 2, that is, the amount of movement of the optical axes of the correction optical systems K ₁ and K ₂ , is controlled by the amount of movement of the slide plates 62 ₁ and 62 ₂ . The amount of movement of the center distance of the measurement light beam projected onto the optometrist can be visually observed. The correction optical systems K ₁ and K ₂ configured in this way are connected to each motor 3.
Adjustment drive is performed by controlling 6, 40 ₁ , 40 ₂ . . . by the output of a control calculation circuit which will be described later. Note that the motor 4 is attached to the optical bench 30 ₂ .
Illustrations of motors that function in the same way as those of optical systems K ₁ and 47 ₁ are omitted, and illustrations and explanations of other members and parts that appear symmetrically in each optical system K ₁ and K ₂ are omitted.

Next, a processing system such as a control calculation circuit for controlling and driving the present device will be explained based on FIG.
In the figure, reference numeral 70 denotes a control calculation circuit, and this control calculation circuit 70 receives a signal from the drive input section Xa or the data input section Xb and performs control calculations to operate the drive output section Y and the display means Z. It is composed of a microcomputer, etc. The data input section Highly accurate measurements can be made in a short time using the subjective refractometer of the present invention based on the corrected power set based on the input measurement result data. The distance/near change switch 71 of the drive input section Xa is connected to a motor 73 for moving the refractive power test optotype 4 via a drive circuit 72, and its drive signal is supplied to the control calculation circuit 70 to It is designed to provide selection information for refraction measurement for use or near refraction measurement. In this way, when near refraction measurement is selected, the control calculation circuit 70 controls the correction optical system K ₁ ,
The above-mentioned adjustment amount Δ is calculated based on the distance between the optical axes of K ₂ , and the optical axes of the corrective optical systems K ₁ and K ₂ are adjusted according to the amount of change in the visual axes caused by the convergence of the eyes E ₁ and E ₂ to be examined. The moving motor 36 sends a drive signal to bring the optical axes closer together in the direction of the line connecting the centers of the pupils and narrow the distance between the optical axes.
It is now being supplied to In addition, the drive input section
The correction optical system inter-axis movement switch 74 of Xa provides drive information to the movement motor 36 for changing the distance between the respective optical axes of the correction optical systems K ₁ and K ₂ , and receives the command from the control calculation circuit 70 . The output is used to drive the moving motor 36 via a drive circuit 75 forming the drive output section Y. Further, the movement motor 36 is driven by the operation of the correction optical system inter-axis movement switch 74, and the aiming plate 23 is driven.
When a and 23b move to determine the interpupillary distance, the value is displayed on the interpupillary distance display section 76 that constitutes the display means Z. Note that the interpupillary distance is determined by the data input section.
It is also controlled by commands from the interpupillary distance data section 77 that constitutes Xb.

Further, the spherical power changing switches 78 ₁ and 78 ₂ of the drive input section Xa provide drive information to the moving motors 40 ₁ and 40 ₂ of the first group lens systems 6 ₁ and 6 ₂ , and the control calculation circuit 70 and Drive signals are applied to the motors 40 ₁ and 40 ₂ via drive circuits 79 ₁ and 79 ₂ of the drive output section Y. thus,
When the spherical power changes, a corresponding value is displayed on the spherical power display section 80 of the display means Z. The spherical power is determined by the spherical power data section 8 of the data input section Xb.
It is also controlled by a signal from 1.

Further, the cylindrical power changing switches 82 ₁ and 82 ₂ of the drive input section Xa are connected to the first and second cylindrical lenses 9.
₁ , 9 ₂ , 9 ₁ , and 9 ₂ to provide drive information to the motors 44 ₁ and 44 ₁ that rotate the motors 44 1 and 44 1 in opposite directions.
The motor 44 is connected to the motor 44 via the control calculation circuit 70 and the drive circuits 81 ₁ , 83 ₂ , 83 ₁ , 83 ₂ of the drive output section Y.
₁ , 47 ₁ to provide a drive signal.
When the cylinder power changes in this way, the value is displayed on the cylinder power display section 84 of the display means Z accordingly. Further, the cylinder power is also controlled by a signal from the cylinder power data section 85 of the data input section Xb.

Further, the cylindrical axis angle change switches 85 ₁ and 85 ₂ of the drive input section Xa are connected to the first and second cylindrical lenses 9 ₁ ,
It provides drive information to the motors 44 ₁ , 47 ₁ that rotate the motors 9 ₂ , 9 ₁ , 9 ₂ in the same direction, and the control calculation circuit 70 and the drive circuit 83 ₁ , of the drive output section Y
Motors _{44 1} , 47 1 via 83 ₂ , 83 ₁ , 83 ₂
It is designed to provide a drive signal to the In this way, once the angle of the cylinder axis is determined, its value is displayed on the display means Z
is displayed on the cylinder axis angle display section 86. Further, the angle of the cylinder axis is also controlled by a signal from the cylinder axis angle data section 87 of the data input section Xb.

Further, the cylinder axis angle change switches 85 ₁ , 85 ₂ of the drive input section Xa are connected to the first and second circular pillar lenses 9 ₁ ,
It provides drive information to the motors 44 ₁ , 47 ₁ that rotate the motors 9 ₂ , 9 ₁ , 9 ₂ in the same direction, and the control calculation circuit 70 and the drive circuit 83 ₁ , of the drive output section Y
Motors _{44 1} , 47 1 via 83 ₂ , 83 ₁ , 83 ₂
It is designed to provide a drive signal to the In this way, once the angle of the cylinder axis is determined, its value is displayed on the display means Z
is displayed on the cylinder axis angle display section 86. Further, the angle of the cylinder axis is also controlled by a signal from the cylinder axis angle data section 87 of the data input section Xb.

The horizontal deflection prism change switches 88 ₁ and 88 ₂ of the drive input section Xa provide drive information to the motors 52 ₁ and 52 ₂ for rotating the horizontal deflection prisms 10 ₁ , 10 ₁ , 10 ₂ , and 10 ₂ . The motors 52 ₁ , 52 ₂ are supplied via the control calculation circuit 70 and the drive circuits 89 ₁ , 89 ₂ of the drive output section Y.
It is designed to provide a driving signal to the Further, the vertical deflection prism change switches 90 ₁ and 90 ₂ of the drive input section Xa are connected to the vertical deflection prisms 11 _{1 and} 90 2 , respectively.
Motor 56 ₁ for rotating 11 ₁ , 11 ₂ , 11 ₂ ,
56 ₂ , and the control calculation circuit and the drive circuit 91 ₁ , 91 ₂ of the drive output section Y
A drive signal is applied to the motors 56 ₁ and 56 ₂ via the motors 56 1 and 56 2 . In this way, the deflection prism 10 ₁ ,
The skew correction prism values obtained by the rotations of 10 ₁ , 11 ₁ , 11 _{1 .} . . are displayed on the skew correction prism value display section 92 of the display means Z. Further, the prism value is also controlled by a signal from the skew correction prism value data section 93 of the data input section Xb.

Note that the signals corresponding to the values displayed on the respective display sections 76, 80, . Upon receiving the output of the synthesis circuit 95, the result of the refractive power measurement to be corrected is displayed on the screen of the monitor television 27.

Next, a control example of the control calculation circuit 70 will be explained. For example, in order to obtain the desired spherical power and cylindrical power by operating the spherical power change switch 78 ₁ or the cylindrical power change switch 82 ₁ , it is necessary to use the corrective optical system.
K ₁ first group, second group and third group lens system 6 ₁ ,
7 ₁ , 8 ₁ (hereinafter referred to as spherical optical system) and the first
And the second cylindrical lenses 9 ₁ and 9 ₁ (hereinafter referred to as cylindrical optical system) may be adjusted as follows. In other words, since the composite refractive power of the spherical optical system and the cylindrical optical system is expressed as a function of the intersection angle of each axis of the first and second cylindrical lenses 9 ₁ and 9 ₁ , the intersection angle corresponding to the spherical power or the cylindrical power is Make adjustments to set it to .

In addition, when obtaining the angle of the cylinder axis using the cylinder axis change switch 85 ₁ , only the angle determined by the sum or difference between the intersection angle of each axis of the first and second cylinder lenses 9 ₁ and 9 ₁ and the reference angle is used. The first cylindrical lens 9 or the second cylindrical lens 9 ₁ is rotated.

Furthermore, in order to obtain a desired prism value using the horizontal deflection prism change switches 88 ₁ and 88 ₂ , a predetermined relational expression must be established between the rotation angle of the deflection prisms 10 ₁ and 10 ₁ and the prism value. Therefore,
The deflection prisms 10 ₁ and 10 ₁ are rotated by an angle corresponding to the prism value. When obtaining the vertical prism value, use the horizontal deflection prism 10 ₁ ,
In addition to considering that it is arranged perpendicularly to 10 ₁ , the vertical deflection prism 11 is
₁ , 11 ₁ rotation control.

As explained above, according to the present invention, when performing near refraction measurement after distance refraction measurement, the refractive power test optotype is formed as a pair of optical images in front of both eyes to be examined. In addition to being able to move closer to the corrective optical system, the distance between the centers of the measurement light beams passing through each corrective optical system can be changed according to the amount of change in the visual axis of the eye being examined, so it is possible to change the distance between the centers of the measurement light beams passing through each corrective optical system depending on the amount of change in the visual axis of the eye being examined. Corresponding corrections can be made, and in both distance and near refraction measurements, there is no need to block the area in front of the subject's eyes during measurement and cause psychological upset. There is no need to insert an angle prism to create near natural vision during refraction measurement, improving measurement efficiency. Furthermore, since insertion of an angle prism can be avoided, appropriate near refraction measurement can be performed without impairing fusion.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a luminous flux state for explaining the principle of the present invention, and FIGS. 2 to 11 are diagrams explaining an embodiment in which the present invention is applied to a subjective refractometer. Figure 2 is a perspective view showing the arrangement of the optical system of the subjective refractometer, Figure 3 a, b
are schematic diagrams showing the luminous flux state of the measuring optical system in distance refraction measurement, in which Fig. 3a shows the case of 0 dayopter, Fig. 3b shows the case of -10 dayopter, Fig. 4a, Fig. 4b is a schematic diagram showing the luminous flux state of the measurement optical system in near refraction measurement; Fig. 4a is for 0 dayopter, and Fig. 4b is for -
Figure 5 shows the case of a 10-day opter.
The figure is a schematic diagram showing the arrangement of the index projection system, FIG. 6 is a schematic diagram showing the index of the index projection system, and FIGS. 7 and 8 are schematic diagrams showing the index of the aiming optical system. 9 shows the optotype image of one index board, and FIG. 8 shows the index image of the other index board, and FIGS. Figure 9b shows the state before adjustment, Figure 9c shows the state after the adjustment in the vertical direction, Figure 9c shows the state after the working distance has been set, and Figure 9d shows the state after the horizontal adjustment. FIG. 10 is a perspective view showing the lens drive mechanism of the corrective optical system, and FIG. 11 is a block diagram illustrating a circuit for controlling the lens drive mechanism. 4... Optotype for refractive power test, 5... Measurement optical system,
K ₁ , K ₂ ... Corrective optical system, E ₁ , E ₂ ... Eye to be examined.

Claims (1)

[Claims] 1. A refractive power test optotype movable in the optical axis direction;
a pair of corrective optical systems whose refractive powers can be changed according to the refractive degrees of both eyes to be examined, and whose optical axis distance can be changed; an image of each of the corrective optical systems is formed in front of the eyes of the eyes to be examined; and the optotype; and a measurement optical system arranged to project a refraction target, and when performing near refraction measurement after distance refraction measurement, the optotype is moved in a direction closer to the correction optical system, and each A refractometer for distance and near vision, characterized in that the images of the corrective optical system can be brought closer to each other according to the amount of change in the visual axis of the eye to be examined.