JPH05176893A - Subjective ophthalmoscopic apparatus - Google Patents

Abstract

PURPOSE:To allow an examinee to easily compare two targets. CONSTITUTION:When eyesight or sight function is measured by arranging a plurality of lenses to the lens disc of a subjective ophthalmoscopic apparatus, a cross cylinder lens unit 16 is arranged to the lens disc at a predetermined position. The cross cylinder lens unit 16 is constituted by parallelly arranging two cylinder lenses 16a, 16b of the same degree within the same plane in a freely revolvable manner. A separation prism is arranged between the cross cylinder lens unit 16 and the eye of the examinee. The separation prism separates the targets shown through two cylinder lenses 16a, 16b to form an image. Two cylinder lenses 16a, 16b are rotated in such a state that positional relation wherein minus axial lines cross each other at 90 deg. is held without changing the positional relation of the separation prism.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subjective eye examination apparatus capable of performing a cross cylinder test, and more particularly to a subjective eye examination apparatus which measures a visual acuity or a visual function by disposing a plurality of lenses on a lens disk.

[0002]

2. Description of the Related Art Conventionally, subjective eye examination apparatuses have been used for measuring a precise astigmatic axis and a precise astigmatic power of a person to be measured. In this type of measurement, a method called a cross cylinder test has been conventionally used, and a cylinder lens is presented in front of the subject's eye by presenting an optotype such as characters on a visual acuity chart. In that case, it is necessary to present the same visual target to the person to be measured in a state where the negative axis and the positive axis of the cylinder lens are alternately replaced. Therefore, the measurer flips the lens unit to rotate the axis of the cylinder lens placed in front of the person to be measured. Then, the subject was asked about the difference in the appearance of the visual target, and the answer was used to make precise measurements of the power of astigmatism and its axial direction.

In this case, the person to be measured stores the appearance of the optotype each time, and relies on his or her own memory to compare it with the appearance of the optotype presented next. Therefore, accurate measurement is practically impossible. Also, the measurer will repeatedly perform the same operation in the inverted set of the lens unit, which not only requires a lot of time and labor, but also puts a great burden on the person to be measured.
Fatigue increases for both parties.

Therefore, it has been considered to simplify the measurement by using a subjective eye examination apparatus having a built-in electric auto-cross mechanism. For example, according to Japanese Unexamined Patent Publication No. 64-32838, a method of performing a cross cylinder test by repeating forward and reverse rotations of a cross cylinder lens with respect to an astigmatism lens, and a cross cylinder lens whose axes are different from each other by 90 ° are prism lenses. A method for performing a cross cylinder test is shown by using a cross cylinder test lens configured to enable simultaneous comparison of appearances by joining with.

[0005]

However, even when the above-described cross cylinder test lens is used, the two cross cylinder lenses are rotated with respect to the axis of the astigmatism lens in a state where the two cross cylinder lenses are bonded to the prism lens, and The mark is presented to the person to be measured. Therefore, in the cross cylinder test, the measurer must always be aware of the separation direction of the image displayed on the operation unit. Further, also in the subject, since the two images always rotate in accordance with the selection of the axis of the astigmatic lens, the positional relationship between the two images changes, and it becomes difficult to compare the two images depending on how they are viewed. Therefore, in the subjective optometry apparatus, there is a problem in that it is difficult to smoothly carry out a dialogue between the measurement person and the measurement subject due to consideration of the position of the image.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a subjective optometry apparatus that allows the person to be measured to compare the appearances of two optotypes. Another object of the present invention is to link with an astigmatic lens,
By providing a motorized axis and frequency switching mechanism, it is easy for the person to be compared to compare and provides the subjective eye examination device that allows the operator to easily perform the measurement without consideration of the position of the image. That is.

Still another object of the present invention is to provide a subjective eye examination apparatus which can reduce the burden of astigmatism measurement by the cross cylinder lens unit and simplify the lens mechanism, and can be built in the lens unit as an auto cross mechanism. With the goal.

[0008]

According to the present invention, in order to solve the above problems, in a subjective eye examination apparatus for arranging a plurality of lenses on a lens disk to measure visual acuity or visual function, a predetermined position of the lens disk is used. And a cross cylinder lens unit in which two cylinder lenses having the same diopter are rotatably juxtaposed in the same plane while maintaining a positional relationship in which negative axes intersect each other at 90 °. And a separation prism that separates and forms an image of the visual target presented via the two cylinder lenses between the measurement subject and the measurement eye of the measurement subject,
A subjective optometry apparatus is provided.

[0009]

The two cylinder lenses rotate without changing the positional relationship with the separating prism while maintaining the positional relationship in which the negative axis lines intersect each other at 90 °. Therefore, the cross cylinder lens unit itself does not rotate in the visual field of the person to be measured, and the target can be imaged in a state in which the other cylinder lens is obliquely inverted with respect to the one cylinder lens. ..

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing the overall configuration of the subjective optometry apparatus. This subjective optometry apparatus includes a measuring head unit 1 having a visual function including near and far vision and a visual acuity measuring mechanism.
The measurement head unit 1 is composed of a measurement head support unit 2 for instructing the measurement head unit 1 to move up and down and horizontally, an optometry table 3, and a base unit 4 supporting these units 1 to 3. The measurement head unit 1 is composed of a measurement lens unit unit 5 and a PD mechanism unit 6. The feature of the present invention resides in that the left and right unit parts 5a and 5b have an electric auto-cross mechanism incorporated therein as described later.

FIG. 2 is a control block diagram showing a main part of a control mechanism of the subjective optometry apparatus. The main control board 110 is composed of an interface circuit 111, a processor (CPU) 112, a ROM 113, a RAM 114, an RS232C interface 115, and the like.

The CPU 112 has a main control board 11 based on a control program stored in the ROM 113.
Controls 0 as a whole. The ROM 113 stores a plurality of screen data to be displayed on the EL display 111 when measuring a visual function or visual acuity. RAM1
An SRAM or the like is used for 14, and various data such as objective measurement data necessary for subjective measurement of visual function or visual acuity is stored as measurement information. Input devices such as a mouse 101 and an EL display 102 are connected to the interface circuit 111. RS232C interface 1
Reference numeral 15 denotes a PD head substrate 12 built in the PD mechanism section 6.
It is connected to the RS232C interface 121 of 0 and functions as an interface circuit for performing data communication between the main control board 110 and the PD head board 120.

The PD head substrate 120 has a function of controlling left and right head substrates and a visual target control substrate, which will be described later, and includes a processor (CPU) 122 and a ROM 12.
3, RAM124, and RS232C interface 1
25 and the like.

FIG. 3 is a view showing a front appearance of the measuring head unit 1. The measuring head unit 1 is composed of a measuring lens unit unit 5 and a PD mechanism unit 6. Here, the person to be measured is located in the front direction of the measurement head unit 1. The measurement lens unit unit 5 is composed of left and right unit units 5a and 5b, and various measurement lenses and auxiliary lenses for visual function measurement such as spherical measurement, astigmatism measurement, astigmatism axis measurement, and prism measurement of the eye of the subject. A lens is housed, and various visual field states are created by combining these lens groups so that the eye can be examined. Measuring lens unit 5
Is suspended from the PD mechanism section 6, and the PD mechanism section 6 determines the distance between the left eye unit section 5a and the right eye unit section 5b of the measurement lens unit section 5 as the interpupillary distance ( It has a built-in mechanism that adjusts according to PD.

The left and right eye unit portions 5a and 5b of the measuring lens unit portion 5 are provided with measuring windows 5c and 5d, respectively, and the eye is examined while allowing the subject to look through the measuring windows 5c and 5d with both eyes. In this eye examination, in addition to the above adjustment of the interpupillary distance, the vertical direction in which the optical axis of the measuring lens installed in the measurement windows 5c and 5d is also aligned with the visual axis of the eye of the subject in the vertical direction. Adjustment and the distance between the measuring lens and the apex of the cornea of the subject's eye (generally referred to as "vertex"
Is adjusted to a predetermined value, for example, 12 mm.

A supporting member 7 of a head supporting device is fixed to the PD mechanism portion 6, and a fore-and-aft moving device, an up-and-down moving device 9, and a forehead rest member on which the forehead of the person to be measured is brought into contact 10 etc. are provided. The front-back direction moving device is a device that moves the forehead support member 10 in the front-back direction of the measurement subject to adjust the vertex to a predetermined value, and the up-down movement device 9 causes the optical axis of the measurement lens to move to the measurement subject's eye. It is a device that matches the visual axis of the vertical direction.

FIG. 4 is a sectional view taken along the line AA of FIG. The configuration of the electric auto-cross mechanism incorporated in the unit portion 5b will be described with reference to this sectional view. Since the left and right measurement lens systems are symmetrical in the internal configuration, only the measurement lens system of one unit will be described here.

In FIG. 4, the measurement window 5 of the unit portion 5b
The base plate 11 is fixed at a position orthogonal to the optical axis of the lens system extending from d to the target. This base plate 1
1 supports the measurement lens system and the drive system in the unit portion 5b. The auto-cross disk 12 is rotatably supported by a support shaft 13 provided in parallel with the base plate 11 and on the target side thereof.

The automatic cross disk 12 has a measurement window 5d.
Separation prism 14 and prism lens 1 corresponding to
5a, 15b and through holes (not shown) are arranged.
The cross cylinder lens unit 16 composed of the two cross cylinder lenses 16a and 16b is provided at a predetermined rotation angle position of the auto cross disk 12 which is the same as the separation prism 14 by a unit support (not shown). A support shaft 17 parallel to the optical axis of the lens system is also provided on the measurement window 5d side of the base plate 11, and the four spherical lens disks 18a to 1a are provided by this support shaft 17.
8d is rotatably supported.

A base plate 19 is arranged in parallel with the base plate 11 in the unit portion 5b, and a pulse motor 141 is provided therein. This pulse motor 141
Is a switching motor for rotating the automatic cross disk 12, and a drive gear 20 attached to the drive shaft thereof meshes with a gear on the peripheral surface of the automatic cross disk 12. In addition, the base plate 11 has a pulse motor 1
42 is provided, and the drive gear 21 is attached to the drive shaft thereof. This drive gear 21 is used for the base plate 1
9 is meshed with an intermediate gear 22 provided on the gear 9, and the sun gear 23 can be rotated via the intermediate gear 22.

That is, the pulse motor 142 rotates the sun gear 23 around the support shaft 13,
3, the prism lens 15a and the cross cylinder lenses 16a and 16b are simultaneously rotated. Therefore, hereinafter, the pulse motor 142 is referred to as an auto cross motor. In the sun gear 25 that rotates around the support shaft 13 via the intermediate gear 24 by a prism motor (not shown), the other prism lens 15b is
The prism lens 15a is configured to rotate independently.

The two astigmatism lenses 26 and 27 are independently rotatably arranged on a lens disk (not shown) and positioned between the auto cross disk 12 and the spherical lens disk 18a.

FIG. 5 is a plan view showing the positional relationship between the automatic cross disk 12 and each drive mechanism of the lens system. The cross cylinder lens unit 16 composed of cylinder lenses of the same diopter coincides with the measurement window 5d. The auto cross disk 12 is shown in the state.

On the auto-cross disk 12, prism lenses 15a are separated from each other by a rotation angle position of 60 ° (in FIG. 5, the prism lens 15b is on the lower surface of the prism lens 15a and is not visible).
A support base 31 that rotatably supports the through holes 30 and the cross cylinder lenses 16a and 16b is arranged. Further, the automatic cross disk 12 is provided with a switching sensor 151. The two lenses 16 a and 16 b of the cross cylinder lens unit 16 are separated by the support base 30 on the separation prism 14 on the auto cross disk 12.
It is fixed in a fixed positional relationship with respect to. The lens frames 31a of the cross cylinder lenses 16a and 16b,
The gears 31b have the same diameter, and gears that mesh with the intermediate gear 31c are formed on their peripheral surfaces. The lens frame 32 of the prism lens 15a is meshed with the sun gear 23. And this sun gear 23
The intermediate gear 22 that meshes with the
Two are provided.

Here, when the automatic cross disk 12 is rotated by the switching motor 141, the rotational position thereof is detected by the switching sensor 151. When the sun gear 23 is rotated by the auto cross motor 142 via the drive gear 21 and the intermediate gear 22, the rotation position thereof is detected by the auto cross sensor 152. Therefore, by rotating the lens frame 31b meshed with the sun gear 23 on the support base 31, the intermediate gear 31
Two cross cylinder lenses 16a and 16b depending on c
However, they are rotated in the same direction while maintaining the positional relationship in which the negative axes intersect each other at 90 °. The prism lens 15a is also rotated corresponding to the two lenses 16a and 16b of the cross cylinder lens unit 16 when the sun gear 23 rotates via the intermediate gear 22.

Further, a drive gear 33 for the drive shaft of the prism motor 143 is attached.
Engages with an intermediate gear 24 provided on the base plate 11 facing the intermediate gear 22. This intermediate gear 24
Through the sun gear 25 (in FIG. 5, it is on the lower surface of the sun gear 23 and is not visible) through the prism lens 15a.
The lower surface of the prism lens 15b is rotated. Therefore, the prism sensor 153 controls the rotational position of the prism lens 15b.

FIG. 6 is an enlarged view for explaining the lens system arranged in the measurement window 5d during the precision astigmatism measurement. Base plate 1
1, an intermediate gear 34 is arranged around a shaft 35, and the intermediate gear 34 is rotated by an astigmatism lens motor (not shown). The gear formed on the peripheral surface of the lens frame 27a of the astigmatic lens 27 meshes with this intermediate gear 34, and the base direction of the astigmatic lens 27 can be controlled to a predetermined rotation angle.
Similarly, the base direction of the astigmatism lens 26 supported by the lens frame 26a of the astigmatism lens 26 is controlled to a predetermined rotation angle by another astigmatism motor (not shown).

The separation prism 14 has an oblique optical path so that it coincides with the optical axes of the two cross cylinder lenses 16a and 16b on the optotype side and the optical axes of the astigmatic lenses 26 on the measurement window 5d side, respectively. Is formed. Two images of the same visual target, which are incident from the cross cylinder lenses 16a and 16b, are imaged in parallel on the astigmatic lens 26 at predetermined intervals via the oblique optical path.
Therefore, even if the lenses 16a and 16b of the cross cylinder lens unit 16 rotate or the base directions of the astigmatic lenses 26 and 27 rotate relative to the measurement eye,
The left and right positional relationship is always maintained for the images of the two separated targets.

FIG. 7 is a control block diagram showing the control mechanism of the lens disk. The left head substrate 130 includes an interface circuit 131 and a drive circuit 132, and is connected to the PD head substrate 120 via the interface circuit 131. To the interface circuit 131, a switching sensor 151, an auto cross sensor 152, a prism sensor 153, an astigmatism lens sensor 154, and a spherical lens sensor 155 are connected. In addition to the switching motor 141, the auto cross motor 142, the prism motor 143, the astigmatic lens motor 144 and the spherical lens motor 145 are connected to the drive circuit 132.

FIG. 8 is a diagram showing the rotational position of the automatic cross disk 12 during spherical surface measurement or astigmatism measurement. The through hole 30 is provided in the auto cross disk 12 with the prism lenses 15a and 15b and the cross cylinder lenses 16a and 16b.
It is arranged at an intermediate position with respect to b. Therefore, the lens system can be compactly built in the unit portion 5b, and one switching motor 141 can be operated with respect to the measurement window 5d to easily switch the measurement.

FIG. 9 is a diagram showing the rotational position of the auto cross disk 12 during prism measurement. In the prism measurement, the two prism lenses 15a and 15b are independently rotated by the auto-cross motor 142 and the prism motor 143 to create a composite degree of desired prism values. Therefore, unlike the conventional prism measurement, it is not necessary to prepare and place prism lenses having various dioptric powers in advance, so that the rotation mechanism of the lens disk is simply configured.

FIG. 10 is a schematic diagram for explaining the action of the lens system for the precise astigmatism measurement. When the cross cylinder test is performed, Stokes' astigmatism lenses 26, 2
7 is in front of the measuring eye 40, four spherical lens disks 1
It is arranged via lenses 41a to 41d arranged on 8a to 18d. The astigmatic lenses 26 and 27 can set the combined astigmatic axis direction and astigmatic power by rotating their axes. When the astigmatic power and the astigmatic axis are changed by these astigmatic lenses 26 and 27, the spherical power can be corrected at the same time by controlling the rotational positions of the four spherical lens disks 18a to 18d. Here, the lens system constituted by the lenses 41a to 41d can be switched in steps with a spherical power of 0.125 (D).

For precise measurement of the astigmatic axis, the cross cylinder lenses 16a and 16b are set to have a positional relationship of 45 ° and 135 ° with respect to the minus axes of the astigmatic lenses 26 and 27, respectively. Further, in the precision measurement of the astigmatic power, the negative axes of the cross cylinder lenses 16a and 16b are set to have a positional relationship of 90 ° and 180 ° with respect to the negative axes of the astigmatic lenses 26 and 27, respectively. The separation prism 14 is arranged between the cross cylinder lenses 16a and 16b and the two astigmatism lenses 26 and 27. As a result, the visual target presented to the person to be measured is separated, and observed by the measurement eye 40 as two images formed through the lens system having a predetermined spherical power.

FIG. 11 is a diagram showing an example of an input screen of the subjective optometry apparatus. Conventionally, in an optometry apparatus with a display, a control box in which a large number of switches are arranged has been used as a means for inputting optometry information displayed on the display. For this reason, the measurer needs to have knowledge of all the switches, which is burdensome.

Further, since the measurer has to perform the measurement while alternately looking at the three locations of the optometer, the display and the control box, there is a problem that the moving distance of the eye is large and the operator is easily tired.

Therefore, in the subjective optometry apparatus of the present invention, in order to maintain the visibility of the input screen and enhance its operability,
In the basic measurement screen 200 as shown in FIG. 11, auto cross switches 201R and 201L are provided. This basic measurement screen 200 is the EL display 10 shown in FIG.
This is one of the screens displayed in 2. The auto-cross switches 201R and 201L are switches that open a window 202 including switches necessary for executing the auto-cross test for the right and left measurement eyes, respectively. In FIG. 11, the left window is open.

In addition to the auto cross switches 201R and 201L, the basic measurement screen 200 is provided with a prism measurement switch, a near vision measurement switch, a visual target switch, and the like. These switches are arranged to open an operation menu necessary for the corresponding measurement and a display window containing measurement information. The measurement information display window 203 displays measurement information such as measurement results such as spherical power and astigmatic power. The standard optotype operation key group 204 is arranged slightly below the center of the screen, and only the command keys of the optotypes that are normally used are displayed.

In the operation menu of the window 202, an astigmatic axis measurement switch (AX) 202a, axial adjustment switches 202b and 202c, and an astigmatic power measurement switch (CYL) 202d are arranged.

FIG. 12 and FIG. 13 are flow charts showing the procedure of precision astigmatic axis measurement and precision astigmatic power measurement, respectively. Here, after determining the precise astigmatic axis of FIG.
The precise astigmatic power of 3 is determined. In the figure, the numerical value following S indicates a step number.

When either the automatic cross switch 201R or 201L is first selected from the basic measurement screen 200, one of the left and right measurement windows 5c and 5d is closed, and the automatic cross test can be executed for each eye. (Step S1). And the measurement switch (AX) 20
If 2a is selected by clicking with the mouse 101, the basic measurement screen 200 changes to the auto-cross AX measurement screen (step S2). At that time, the automatic cross disk 12 is rotationally controlled to the position shown in FIG. 5 by the switching motor 141 (step S3), and at the same time calculates the corresponding astigmatic axis (step S4). Further, the automatic cross motor 142 is driven (step S5), and the cross cylinder lenses 16a and 16b are positioned based on the measurement value of the astigmatic axis measured in advance. As the measurement value, for example, a measurement value obtained by an objective measuring device before the subjective eye examination is used, or a value set by inputting data of the person to be measured by an inquiry or the like can be used.

An axial adjustment switch 20 for adjusting the axial direction of the astigmatic axis
It is changed by either 2b or 202c, and the subject is asked to answer whether or not the appearances of the two optotypes match (step S6). According to the result of the left-right comparison, the measurer further determines that the axial adjustment switch 202b,
Any one of 202c is operated to change the astigmatic axis (step S7). The precise astigmatic axis is determined while adjusting according to the response of the person to be measured until the axes match (step S
8).

Further, when measuring the astigmatic power, if the measurement switch (CYL) 202d is selected (step S1)
1), the basic measurement screen 200 changes to an auto-cross CYL measurement screen. At this time, the automatic cross motor 142 is controlled according to the astigmatic power stored in the subjective optometry apparatus, whereby the cross cylinder lenses 16a, 1
6b is set to a predetermined rotation angle position. Steps S11 to S17 in FIG. 13 correspond to steps S2 to S8 in FIG.

In order to input a command from these operation menus, a mouse 101 shown in FIG. 2 is used to move a cursor called an "icon" displayed on the screen, and a predetermined command button provided on the mouse 102 is moved. It can be executed by pressing.

By the way, even if these operation windows are newly displayed in the basic measurement screen 200, the measurement information indispensable for measurement is still displayed in the measurement information display window 203. Therefore, the rotation of the automatic cross disk 12 is controlled while constantly monitoring the measurement information to enable the cross cylinder test. Therefore, in the subjective optometry apparatus for measuring the visual function or visual acuity of the eye by the interaction with the person to be measured, a measurement information display window displaying measurement information of the visual function or visual acuity and an operation window displaying a plurality of command keys are provided. By using an input screen that displays simultaneously, it not only simplifies the measurement but also enables centralized control.

[0045]

As described above, in the present invention, the visual target seen by the person to be measured through the cross cylinder lens is always observed at the same position. That is, for the person to be measured, 2
Since there is no change in the positional relationship between the two images, it is only necessary to compare their appearances. Therefore, it is possible to improve the measurement accuracy in the cross cylinder test and reduce fatigue of the person to be measured.

Also, for the measurer, there are 2
Since it is not necessary to consider the positions of the two images, the burden of subjective eye measurement is reduced, and in particular, it is possible to concentrate on the motorized lens switching operation along with the optotype operation, so that accurate measurement results can be easily obtained. be able to.

[Brief description of drawings]

FIG. 1 is a front view showing the overall configuration of a subjective optometry apparatus of the present invention.

FIG. 2 is a control block diagram showing a main part of a control mechanism.

FIG. 3 is a diagram showing a front appearance of a measurement head unit.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is a plan view showing the positional relationship between the automatic cross disc and each drive mechanism of the lens system.

FIG. 6 is an enlarged view illustrating a lens system.

FIG. 7 is a control block diagram showing a control mechanism of a lens disc.

FIG. 8 is a diagram showing a rotational position of an auto cross disk during spherical surface measurement or astigmatism measurement.

FIG. 9 is a diagram showing a rotational position of the auto cross disk 12 during prism measurement.

FIG. 10 is a schematic diagram illustrating an operation of a lens system for precise astigmatism measurement.

FIG. 11 is a diagram showing an example of an input screen of the subjective optometry apparatus.

FIG. 12 is a flowchart showing a procedure of precise astigmatic axis measurement.

FIG. 13 is a flowchart showing a procedure of precise astigmatic power measurement.

[Explanation of symbols]

 1 Measuring Head 5d Measuring Window 12 Auto Cross Disc 14 Separation Prism 16a, 16b Cross Cylinder Lens

Claims (3)

[Claims] 1. An subjective optometry apparatus for measuring visual acuity or visual function by arranging a plurality of lenses on a lens disk, wherein two cylinder lenses having the same dioptric power are provided at predetermined positions of the lens disk, and their negative axes are 90 degrees each other. A cross cylinder lens unit that is rotatably juxtaposed in the same plane while maintaining a positional relationship where the cross cylinder lens unit and the eye to be measured of the measurement subject are arranged. An subjective optometry apparatus comprising: a separation prism that separates and forms an image of a target presented through a cylinder lens. 2. The cross cylinder lens unit,
The subjective optometry apparatus according to claim 1, wherein the opening and the prism lens unit are provided on a lens disk each having a predetermined position. 3. A first rotating means for rotating a lens disk having the cross cylinder lens unit, a second rotating means for rotating two cylindrical lenses of the cross cylinder lens unit, and the first and second rotating means. 3. The subjective optometry apparatus according to claim 1, further comprising a control unit that electrically controls switching of the rotation unit.