JPH09168512A - Optometry instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform optometry by selecting a degree of an astigmatism check lens according to an eye to be examined. SOLUTION: The optometry instrument in which several selectable optical elements including astigmatism lenses are attached to optometry windows and this instrument is subjectively used to check the ocular refraction of an eye to be examined, is provided with an auxiliary lens disc which is equipped with two types of cross cylinder test lenses 32 and 33 whose cylindrical lens degrees are different. The cross cylinder test lenses are optically equivalent to two cylindrical lenses whose axes intersect at right angles and polarities are different to each other, and one of the cross cylinder test lenses is selected to the inserted into the optometry window.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optometry apparatus for inspecting astigmatism using a cross cylinder test lens.

[0002]

2. Description of the Related Art A device using a cross cylinder test lens is known as a device for subjectively inspecting the dioptric power and axis of an eye to be inspected. The cross cylinder test lens is obtained by joining two cylindrical lenses having the same absolute value and different signs with their axes shifted by 90 °.
The apparatus is equipped with one type of cross cylinder test lens. In the examination, the subject is first placed in front of his / her eyes, a predetermined target is shown to the subject via the eye, and the appearance of the target at that time is stored. After that, 9 lenses for cross cylinder test
The subject is shown the optotype again in a state where the optotype is rotated by 0 °, and is compared with the appearance of the previous optotype to determine the astigmatic power and axis of the eye to be examined.

[0003]

However, in this apparatus, the subject is required to judge the appearance based on the memory, but there is a problem that delicate judgment is difficult due to the limit of the memory. In precision measurement of astigmatism, when the eyesight of the subject's eye is high (for example, 0.7), a low-frequency (± 0.25 diopter) cross cylinder test lens is desirable. .5 diopter is good,
There is a problem that such selection cannot be made according to the state of the subject. An object of the present invention is to provide an optometric apparatus capable of performing a cross-cylinder test according to the state of a subject in view of the above-described problems of the related art.

[0004]

The present invention has the following constitution in order to solve the above problems. (1) In an optometry apparatus for subjectively inspecting the refractive power of an eye to be inspected by arranging optical elements including an astigmatism lens in an optometry window, it is optically equivalent to two cylindrical lenses whose axes are orthogonal to each other and have different polarities. A cross-cylinder test lens, which is an auxiliary lens disc having two types of cross-cylinder test lenses distinguished by the power of the cylindrical lens, and an auxiliary lens disc that rotatably holds the axis of the cross-cylinder test lens. A driving means for driving the auxiliary lens disk to replace the cross cylinder test lens in the eye examination window, and a selection for selecting one of the cross cylinder test lenses to be inserted in the eye examination window. And a control means for operating the drive means in response to the selection of the selection means, and the control means inserted into the optometry window. Second driving means for rotating the axis of the cross cylinder test lens, and positioning the axis of the cross cylinder test lens based on the astigmatism axis of the astigmatism lens inserted into the eye examination window, and Second control means for controlling the second driving means so as to rotate the cross cylinder test lens in synchronization with the movement of the astigmatic axis.

(2) In the optometry apparatus of (1), a selection switch for selecting the precision astigmatism diopter test and the precision astigmatism axis test is further provided, and the second control means in the previous term is the cross cylinder test lens according to the selection of the selection switch. The axis of is changed by 90 degrees.

[0006]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of the left eye measurement unit of the optometry apparatus main body according to the present invention as viewed from above. Reference numeral 1 denotes a measurement optical axis, and a visual acuity chart (not shown) is provided on an extension of the optical axis. The subject responds to a question of the examiner while looking at the visual acuity chart via various lenses disposed in front of the subject's eye 2. I do. An auxiliary lens disk 4A, a strong spherical lens disk 5, and a weak spherical lens disk 6 are arranged around the axis of rotation 3, and a plurality of auxiliary lenses 7 and a strong spherical lens 8 are arranged on the same circumference of each disk. , A weak spherical lens 9 is disposed. The outer periphery of the weak spherical lens disk 6 is connected to a gear of a weak spherical lens rotating motor 11 via a gear 10. The other disks are similarly switched by a motor (not shown).

The positive astigmatism lens disk 12 and the negative astigmatism lens disk 13 can be independently rotated about a measuring optical axis 1 by a motor (not shown), and have the same power and different signs. Fifteen
Are arranged, and by changing the astigmatic axis of each lens relatively, the power of the astigmatic lens can be continuously changed. The switching motor 1 for the auxiliary lens disk 4B rotates about the axis 3a.
6 allows it to rotate via a gear 17. Prism disk 2 rotatable around measurement optical axis 1
0 and the prisms 18 and 19 disposed on the prism disk 21 have the same declination, and the refractive power of the prism can be continuously changed by a relative change in the rotation direction. The sun gear 22 has a gear 23 fixed thereto and functions to transmit the rotation of the rotation motor 24 to the prism disk 20. The above mechanism is sealed by a cover 27, a protective glass 28, and a protective glass 29.

FIG. 2 shows an auxiliary lens disk 4B with the eye 2 to be inspected.
FIG. 5 is a view from the side, and shows a prism 18, a prism 19, a hole 30, a -0.12 diopter (hereinafter abbreviated as D) spherical lens 31, a cross cylinder lens 32, 33, 34, an auxiliary astigmatism on an auxiliary lens disk 4B. A lens 35 is arranged and is rotatable by the rotation motor 24 via the sun gear 22. 32 is a + 0.25D cylindrical lens,
This is a lens in which the cylinder axis of a −0.25D cylindrical lens is orthogonally combined, and 33 cross cylinder lenses are 3
The column power is different from 2 and both are selected and used according to the condition of the subject. Cross cylinder test lens 34
As shown in FIG. 3, cross-cylinder lenses 37 and 38 whose axes are different from each other by 90 ° are joined to a symmetrical prism 36 having a thick central portion and a thin peripheral portion, as shown in FIG. Since the light is deflected by the prism 36, the visual acuity table is observed separately in two directions of the visual line 39 and 40. Since the separated visual acuity chart images pass through the cross cylinder lenses 37 and 38, the subject can perform the cross cylinder test by comparing the two left and right images.

FIG. 4 is a control block diagram of the embodiment shown in FIG. 41, 42, 43, 44, and 45 are selection switches for spherical power, astigmatic power, axis angle, prism power up / down direction, and prism power left / right direction, respectively, 48 is a rotary encoder for changing each power, and 47 is a waveform. A shaping circuit 49 is an input circuit. Microprocessor 50,
The control unit constituted by the memories 51 and 52 sends a motor drive command through the output circuit 53 to the motor drive circuits 54 to 6.
Send to 1. Reference numerals 11, 16, 24, 26, and 62 to 65 denote motors for driving the disk lenses, respectively.

Next, the operation of the apparatus of this embodiment based on the above configuration will be described. (Switching of Spherical Power) When the examiner presses the spherical power selection switch 41 and then rotates the rotary encoder 48, the CPU 50 outputs an output circuit 53 and a motor drive based on the rotation direction and rotation angle of the rotary encoder 48. Drive signals are issued to the strong spherical lens switching motor 63 and the weak spherical lens switching motor 11 through the circuits 55 and 56, and the strong spherical lens disk 5 and the weak spherical lens disk 6 in FIG. A combination is selected and set on the measurement optical axis 1. The strong spherical lens disk 5 has 12 spherical lenses in 3D units, and the weak spherical lens disk 6 has 12 lenses in 0.25D units. The spherical power is -19 in 0.25 units.
It can be switched up to 16.75D. (Switching between astigmatic power and astigmatic axis) In FIG. 1, a plus astigmatism lens 14 and a minus astigmatism lens 15 are so-called Stokes.
If the power of each lens is D, the angular difference between the cylinder axes is ε, the synthetic astigmatic power is Dε, and the synthetic axial angle is Ax, then Dε = -2Dsin ε Ax = ε / The relational expression of 2-90 ° holds.

In FIG. 4, in order for the examiner to change the astigmatism degree, the astigmatism degree selection switch 42 is depressed, and the rotary encoder 48 is rotated by a necessary change amount.
The signal of the rotation amount calculated in is supplied to the plus astigmatism lens rotation motor 64 and the minus astigmatism lens rotation motor 65 to rotate them, thereby generating the astigmatism degree. To change the astigmatism axis, the examiner presses the astigmatism axis selection switch 43 and then turns the rotary encoder 48 to rotate the plus astigmatism lens rotation motor 64 and the minus astigmatism lens rotation motor 65, thereby causing the plus astigmatism lens 14 to rotate. By rotating the minus astigmatic lens 15 in the same direction by the same angle, the astigmatic axis changes. By the way, in the Stokes cross cylinder, a spherical power is generated as the astigmatic power changes. The spherical power Ds is Ds = -Dε / 2. Therefore, it is necessary to cancel this spherical power with another lens. Since the minimum unit of the astigmatic power inspection apparatus is usually 0.25D, the minimum unit of the spherical power to be canceled is 0.12D. In this embodiment, a −0.12D spherical lens is arranged on the auxiliary lens disk 4B of FIG.
By switching between this and the hole 30, the cancellation of 0.12D is performed. An example of the combination is shown below.

[Table 1] The combination of Ds ₁ , Ds ₂ , and Ds ₃ with respect to the astigmatic power Dε is programmed in advance in the ROM 51 so that the CPU 50 can rotate each disk to a predetermined position based on the astigmatic power conversion signal from the rotary encoder 48. This can be achieved by sending a signal to each of the motors 11, 16, 63-65. However, in FIG. 2, when the prisms 18 and 19 are placed on the measurement optical axis 1 to perform prism measurement, or when using the other lenses 32 to 35 on the auxiliary lens disk 4B,
Since the −0.12D lens 31 cannot be used, the −0.12D spherical lens 66 on the auxiliary lens disk 4A shown in FIG. 5 is used. The operation at this time is the hole 30 described above,
As with the switching of the −0.12D lens 31, the holes 7 and −0.
The 12D spherical lens 66 is switched by the switching motor 62 of the auxiliary lens disk 4A.

When performing a cross cylinder test in a binocular open refraction test, the polarizing plate 67 of FIG. 5 and the cross cylinder test lenses 32, 33 and 34 of FIG. 2 are used at the same time. -0.12 above
Although a D spherical lens cannot be used, a lens 68 in which a -0.12D spherical lens is combined with a polarizing plate having the same optical properties as the polarizing plate 67 is prepared for the auxiliary lens disk 4A, and a polarizing plate 67 is formed based on a change in astigmatic power. It becomes possible to correct the -0.12D spherical power by switching the. Auxiliary lens disks used in general subjective inspections include special auxiliary lenses used for oblique measurement or convergence measurement, such as a Maddock lens, a red filter, and a green filter, in addition to a polarized lens. These auxiliary lenses and the prisms of the auxiliary lens disk 4B may be used in combination. However, since all of them are prism measurements and are inspections in a special state in which mechanical myopia, which is not ordinary vision, is likely to occur, The error of the spherical power of 0.12D does not particularly affect the measurement of the prism power.

(Conversion of prism power) When the prism power up / down selection switch 44 in FIG. 4 is pressed, the auxiliary lens disk B4B is switched by the motor 16 and the measurement optical axis 1
A prism 18 and a prism 19 are placed on top. Since the prisms 18 and 19 have the same power, the former has the base direction on the right side in the horizontal direction, and the latter has the base direction on the left side in the horizontal direction, so the prism power is 0Δ. When the rotary encoder 48 is rotated clockwise, a signal is sent from the CPU 50 to the rotation motors 24 and 26, and the prism 18 is rotated clockwise and the prism 19 is rotated counterclockwise by a predetermined angle θ. 19 allows the base direction of the combining prism to be downward. To raise the base direction of the combining prism upward, the rotary encoder 48 may be rotated counterclockwise, the prism A may be rotated counterclockwise, and the prism B may be rotated clockwise. If the rotation angle of the prism is θ, the combined prism power is P, and the prism power of the prism 18 and the prism 19 is P _A , the formula P = 2P _A COS θ holds. Therefore, a program based on this formula is stored in the ROM 51. The required prism power can be realized by setting the above. To change the prism power in the left-right direction, the prism 18 is disposed above the base and the prism 19 is disposed below the base by pressing the prism power left / right selection switch 45. Rotary encoder 4
The left and right sides of the base direction of the synthesis prism are determined by the rotation direction of 8, and the synthesis prism frequency is determined by the amount of rotation, as in the case of the vertical direction.

(Cross Cylinder Test) In the embodiment, there are three lenses for a cross cylinder test, and a lens to be used is selected in advance by a setting switch. 32 is ± 0.
This is a 25D cross cylinder test lens. The cross cylinder test includes precise correction of the astigmatic axis and precise correction of the astigmatic power, which will be described in this procedure. A red-green test chart is placed 5 m in front of the subject's eye, the spherical power selection switch 41 is pressed, the rotary encoder 48 is rotated, and the strong and weak spherical lens disks 5 and 6 are rotated and switched to perform a red-green test. After the characters on the red background and the characters on the green background appear to have the same darkness, −0.25D is further added to match the minimum circle of confusion of the chart image with the fundus of the eye to be examined. Next, the chart is changed to a character index or the like having less directivity, the axis angle selection switch 43 is pressed, the fact that the axis angle measurement mode is set is stored in the RAM 52 via the input circuit 49 and the CPU 50, and the cross cylinder normal rotation switch 46A is turned on. Push. As a result, the switching motor 16 of the auxiliary lens disk 4B is rotated so that the auxiliary lens disk 4B is rotated, the cross cylinder lens 32 is set on the optical axis, and the minus cylinder axis 32 of the astigmatic lenses 14 and 15 is set. The rotary motor 24 is rotated so as to be inclined 45 ° counterclockwise with respect to the minus axis of the synthetic astigmatism. Next, when the cross cylinder reversing switch 46B is pressed, the rotary motor 24 rotates, and the cross cylinder lens 32 rotates 90 °. Repeat this normal rotation and inversion, ask the subject which is clear,
If the rotation is forward, the rotary encoder 48 is rotated counterclockwise so that the astigmatism lenses 14 and 15 are rotated counterclockwise by the same angle. The normal rotation and inversion are repeated again, and the rotary encoder 48 is operated to correct the astigmatic axis angle until the appearance of the normal rotation and the appearance of the reverse become the same.

Next, when precision correction of the astigmatic power is performed, by pressing the astigmatic power selecting switch 42, the minus axis of the cross cylinder lens 32 becomes an angle orthogonal to the combined astigmatic axis of the astigmatic lenses 14 and 15. A signal is issued from the CPU 50, and the motor 24 rotates. Next, when the cross cylinder reversing switch 46B is pressed, the cross cylinder lens 32 rotates 90 °. This operation is repeated, and the astigmatic power is corrected by operating the rotary encoder 48 until the appearance at the time of normal rotation and the time of inversion become the same.

Although the above-described cross cylinder test is the most common, the present embodiment further includes a cross cylinder test lens 34 that allows simultaneous comparison. In FIG. 3, reference numeral 38 denotes a cross cylinder lens whose minus axis is parallel to the base direction of the prism 36.
Is a cross cylinder lens having a minus axis perpendicular to the base direction of the prism 36. With the cross cylinder selection switch 70, the lens 34 is selected as a lens for the cross cylinder test. When the shaft angle selection switch 43 is pressed and the cross cylinder forward rotation switch 46A or the cross cylinder reversal switch 46B is pressed, the lens 34 is turned on as shown in FIG.
And the ridge line of the prism 36 is at 45 ° with respect to the minus axis of the combined astigmatism of the plus and minus astigmatism lenses 14 and 15 as shown in FIG.
Rotate to an inclined angle. FIG. 7 shows this state as viewed from the subject's eye 2 side. The image of one chart character “8” placed at a position about 5 m in front of the subject's eye by the prism action of the prism 36 is represented by a cross cylinder lens 38. The image 71 viewed through the cross cylinder lens 37 and the image 71 viewed through the cross cylinder lens 37 are visually recognized in two parts. FIG. 10 is an external view of the operation unit 75 in this state. The illumination character 77 indicating that the cross cylinder test is being performed is lit, and the lamp 76 indicating that the astigmatic axis measurement is being performed is also lit. . Further, since the RAM 52 stores the rotational position of the lens 34 for the cross cylinder test, the CPU 50 causes the display unit 69 to output the lamp 79 indicating the image separation direction on the side of the cross cylinder lens 38 via the output circuit 53 to the display unit 69. Send a signal. Lamps 80 and 81 are provided on the left and right of the rotary encoder 48. The lamp 80 blinks in a direction in which the rotary encoder is rotated in the plus direction (a direction in which the astigmatic axis angle is changed in a counterclockwise direction), and the lamp 81 is turned on. deep.

The examiner can see the lamps 78 and 79 of the operation unit to confirm the directions of the two images viewed by the subject. And which one looks clearer? " If the subject answers upper left, the minus axis of the combined astigmatism of the plus and minus astigmatism lenses 14 and 15 needs to be turned counterclockwise to correct it. By turning the rotary encoder 48 toward the blinking lamp 80, the axis angle can be easily corrected.

Next, a test of the astigmatic power using the lens 34 will be described. When the astigmatic power selection switch 42 is pressed, the lamp 82 in FIG. 11 is turned on to indicate that the astigmatic power is being measured, and the cross cylinder lens 38 with respect to the minus axis of the combined astigmatism of the plus and minus astigmatic lenses 14 and 15. Lens 3 so that the minus axis of
4 is rotated as shown in FIG. At this time, the image viewed from the eye 2 to be inspected is divided into left and right as shown in FIG. 9, and the image on the left is an image that has passed through the cross cylinder lens 38. 73 in FIG.
The lamp 83 in the direction corresponding to the image of 74 is turned on, the lamp 84 in the direction corresponding to the image of 74 is turned on, the lamp 81 in the direction in which astigmatism increases, and the lamp 80 in the direction in which astigmatism decreases is turned on and off. Keep it. The examiner is the lamp 8 in FIG.
While looking at 3, 84, the direction of separation of the image seen by the subject's eye is determined. You can ask, "Which of the figure on the right or the figure on the left is clearly visible?" If the subject replied "left," the same as the lit left lamp 83 The rotary encoder 48 is attached to the blinking lamp 80 side.
Turning the. If the answer is right, the rotary encoder 48 is turned to the ramp 81 side. In this way, the astigmatic power is corrected until the images 73 and 74 are almost the same.

In the above example, the image separation direction extends up and down and left and right, but the image can be separated only in the left and right direction by the following procedure. In this case, only two lamps indicating the image separation direction are required. That is, in the astigmatic power cross cylinder test, the combined astigmatic axis of the plus and minus astigmatism lenses 14 and 15 is 45 ° to 1 °.
In the case of 35 °, the minus axis of the cross cylinder lens 37 is made to coincide with the synthetic astigmatism axis, and the lamp 83 side in FIG. ° range, left 180 ° ±
It can always fit within the 45 ° range. In the cross cylinder test of the astigmatic axis, the synthetic astigmatic axis is 0 ° to 9 °.
When it is 0 °, it is set at an angle of 45 ° counterclockwise with respect to the minus axis of the cross cylinder lens 37 and the minus axis of the synthetic astigmatism, so that the right lamp indicating the image separation direction blinks and the left lamp is turned on. And also flashes 80, 8
1 is turned on. When the combined astigmatism axis is 90 ° to 180 °, it is set at an angle of 45 ° counterclockwise with respect to the minus axis of the cross cylinder lens 38 and the minus axis of the combined astigmatism, and the left lamp and 80 are blinked. Ramp and 81
Lights up. In addition, in the above embodiment, the display is performed by turning on and blinking a lamp as a device that does not require cost. However, a display based on color distinction using a two-color LED or the like may be used, or a liquid crystal display CRT display or the like may be used as a display unit. By giving instructions using characters, it becomes easier to use. As the character display, for example, it is displayed as shown in FIG.

[0020]

As described above, according to the present invention,
By providing two types of cross-cylinder test lenses with different powers, it is possible to select the power of the cross-cylinder test lens according to the condition of the subject's eye and perform the optometry. Becomes

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a left side measurement unit of a subjective refractive power inspection device body according to the present invention as viewed from above.

FIG. 2 is a view of an auxiliary lens disk B as viewed from an eye to be inspected.

FIG. 3 is an explanatory diagram of a subjective refractive power inspection apparatus capable of performing simultaneous comparison by separating images.

FIG. 4 is a control block diagram of the subjective refractive power inspection apparatus according to the present invention.

FIG. 5 is a view of the auxiliary lens disk A viewed from the eye to be inspected.

FIG. 6 is an explanatory diagram of a cross cylinder test of an astigmatic axis.

FIG. 7 is a diagram of a chart image viewed from an eye to be examined during a cross cylinder test of an astigmatic axis.

FIG. 8 is an explanatory diagram of an astigmatic power cross cylinder test.

FIG. 9 is a diagram of a chart image viewed from the eye to be inspected during a cross cylinder test of an astigmatic power.

FIG. 10 is an external view of an operation unit during a cross cylinder test of an astigmatic axis.

FIG. 11 is an external view of an operation unit during a cross cylinder test of astigmatic power.

FIG. 12 is a diagram showing an example of character display in a case where a liquid crystal display CRT display or the like is used as a display unit and an instruction is made by using characters.

[Explanation of symbols]

 4A, 4B Auxiliary lens disc 5 Strong spherical lens disc 6 Weak spherical lens disc 12 Positive astigmatism lens disc 13 Minus astigmatism lens disc 14, 15 Astigmatism lens 36 Prism 37, 38 Cross cylinder test lens

Claims (2)

[Claims] 1. An optometry apparatus for subjectively inspecting the refractive power of an eye to be inspected by switchingly arranging optical elements including an astigmatism lens in an optometry window, wherein two cylindrical lenses having different polarities whose axes are orthogonal to each other are optically provided. An equivalent cross cylinder test lens, which is an auxiliary lens disk having two types of cross cylinder test lenses distinguished by the power of the cylindrical lens, and an auxiliary for rotatably holding the axis of the cross cylinder test lens. A lens disk, drive means for driving the auxiliary lens disk to replace the cross cylinder test lens in the optometry window, and one of the cross cylinder test lenses selected to be inserted into the optometry window Selecting means for selecting, and control means for operating the driving means in response to the selection of the selecting means,
Second drive means for rotating the axis of the cross cylinder test lens inserted in the eye examination window, and the axis of the cross cylinder test lens based on the astigmatic axis of the astigmatism lens inserted in the eye examination window And a second control means for controlling the second drive means so as to rotate the cross cylinder test lens in synchronization with the movement of the astigmatic axis of the astigmatism lens. . 2. The eye examination apparatus according to claim 1, further comprising a selection switch for selecting a precision astigmatism diopter test and a precision astigmatism axis test, and the second control means in accordance with the selection of the selection switch is a cross cylinder test lens. Axis 9
An optometry apparatus characterized by being changed by 0 degree.