JPH0443665B2 - - Google Patents

Description

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

The present invention relates to a visual acuity testing device that precisely tests the axis of astigmatism and degree of astigmatism using a cross cylinder lens.

[Conventional technology]

2. Description of the Related Art Conventionally, optical devices for visual acuity tests that combine a cross cylinder lens and a cylindrical lens for correcting astigmatism have been known. In order to test the degree of astigmatism with such a visual acuity test device, the combination of the cross cylinder lens and the cylinder lens is changed by rotating the cross cylinder lens and the cylinder lens according to the subject's awareness. There is. An example of this is, for example, U.S. Patent No. 3,498,699.
An astigmatism testing device using a drive mechanism for a cross cylinder lens and a cylindrical lens as disclosed in Japanese Patent Laid-open No. 59-44237 has been proposed. In the astigmatism testing device disclosed in JP-A-59-44237, the cross cylinder lens and the cylindrical lens are each rotatably driven by separate motors, and each motor is separately operated by a forward rotation switch and a reverse rotation switch. It allows forward and reverse rotation operation. When performing an astigmatism test using such a subjective optometry device, the cross cylinder lens is rotated forward and reversed, and the sharpness of the test target is compared before and after the reversal. It is being said. In this comparison, the examiner asks the examinee whether the front and back before and after the reversal were clearly visible.
This is done based on the subject's response to this question. Furthermore, in making this comparison, it is necessary to change the combination of the cross cylinder lens and the cylinder lens while rotating the cylinder lens according to the subject's awareness as described above.

[Problem to be solved by the invention]

However, when rotating the lens (rotation adjustment) in this astigmatism test, the examiner rotates the cross cylinder lens and cylindrical lens separately using separate switches depending on the patient's response, which takes time. It was something like that. Moreover, as mentioned above, since the examiner operates the cross cylinder lens and the cylindrical lens separately, the examiner may make mistakes in adjusting the direction and amount of rotation of the cross cylinder lens and the cylindrical shaft during astigmatism testing. be. In this case, the operation for the test must be performed again, which is troublesome and also increases the time required for the astigmatism test. Therefore, the present invention has been made to overcome the drawbacks of the above-mentioned prior art, and provides a visual acuity testing device that allows a subject or examiner to easily and quickly perform an astigmatism test. be.

[Means to solve the problem]

In order to achieve this object, the present invention provides an astigmatism correcting optical system including a plurality of cylindrical lenses each having a different refractive power and rotatable around an optical axis, and a cross cylinder lens rotatable around the optical axis. , the visual acuity test device includes first and second lens rotation devices that rotate the cylindrical axis of the cylindrical lens and the axis of the cross cylinder lens by predetermined amounts, respectively, when a switch for lens rotation operation is operated. Features.

【Example】

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below based on embodiments with reference to the accompanying drawings. FIG. 1 is a block diagram of one embodiment. The farsightedness correction optical system is composed of a rotatable spherical lens plate 1 and a plurality of spherical lenses 2 arranged on the same radius of the spherical lens plate 1. This spherical lens plate 1 is rotated about an axis 4 by a far-near vision correction optical system drive motor (hereinafter referred to as "near-near vision drive motor") 3, and one of the plurality of spherical lenses 2 is rotated to look at an inspection target P. Selectively arranged in the observation optical path. The astigmatism correction optical system includes a rotatable cylindrical lens plate 5
and a plurality of cylindrical lenses 6 arranged on the same radius of the cylindrical lens plate 5. This cylindrical lens plate 5 is connected to the astigmatism correction optical system drive motor (hereinafter referred to as "astigmatism drive motor") with the axis 7 as the center.
) 8 to selectively arrange one of the plurality of cylindrical lenses 6 in the observation optical path. Further, the cylindrical lens 6 is connected to an astigmatism correction optical system cylindrical shaft rotation motor (hereinafter referred to as "astigmatism rotation motor") 9.
(first lens rotation device). A cross cylinder lens (hereinafter referred to as "CC lens") 10 is provided so as to be rotatable by a second lens rotation device. This second lens rotation device includes a cross cylinder lens axis rotation motor (hereinafter referred to as "CC axis rotation motor") 11 and a cross cylinder lens reversal motor (hereinafter referred to as "CC reversal motor") 12. The motors 3, 8, 9, 11, 12 shown above are
For example, it is controlled by a control section 13 composed of a microprocessor or the like. This control unit 13 includes a memory 14 for storing programs, etc., a keyboard 15 for inputting operation information, etc., a CRT 16 for displaying control information, test results, etc., and a clear view of the test target P. A test subject response switch (hereinafter referred to as "response switch") 17, etc., which is operated by comparing the superiority and inferiority of degrees, is connected. FIG. 2 is a control block diagram of the embodiment shown in FIG. 1. Note that the same elements as in FIG. 1 are indicated by the same symbols. S input by the examiner from the keyboard 15
(sphericity), C (cylindricity), and AX (cylindrical axis) data are sent to a motor rotation amount calculation circuit (hereinafter referred to as "calculation circuit") 21 that calculates the rotation amount of each motor 3, 8, 9, 11, and 12. Given. Further, a signal from the response switch 17 is given to an arithmetic circuit 21 via a discrimination circuit 22, and a memory 14 is connected to the arithmetic circuit 21 via a CPU 23. The output of the arithmetic circuit 21 is passed through the conversion circuit 24.
It is applied to the CRT 16, where it is output and displayed, and is also sent to each motor 3, 8, through a gate circuit 25.
Motor controller 2 that controls 9, 11, 12
Given between 6 and 30. The motor controllers 26 to 30 are supplied with pulses from a pulse oscillator 31, thereby controlling each motor 3, 8, 9, 1, which is a pulse motor.
1 and 12 are driven to rotate. Next, referring to the flowchart in Figure 3,
The operation of the embodiment shown in the figure and FIG. 2 will be explained. The following explanation of the operation is based on the fact that the refractive power of the eye to be examined has been measured in advance with an objective ophthalmoscope, and this is used to precisely measure astigmatism using the CC lens of the device of the present invention. . First, after a reset operation (step 100), S (sphericity) data is input from the keyboard 15 (step 101), and based on this, the calculation circuit 21 calculates the amount of rotation of the distance drive motor 12 (step 102). . The calculation result is given to the motor controller 30 via the gate circuit 25, which rotates the distance drive motor 12 by a predetermined amount and sets the spherical lens 2 with a predetermined degree of sphericity on the optical axis (step 103). ). The sphericity S of the spherical lens 2 thus set is displayed on the CRT 16 (step 104),
As a result of the comparison of sharpness by the subject, if the desired sphericity is obtained, the process proceeds to the next step (step 105). Next, C (cylindricity) data is input from the keyboard 15 (step 111), and based on this data, the rotation amount of the astigmatism drive motor 8 is calculated by the calculation circuit 21 (step 112). This calculation result is given to the motor controller 29 via the gate circuit 25, which rotates the astigmatism drive motor 8 by a predetermined amount to set the cylindrical lens 6 with a predetermined cylindricity on the optical axis (step 113). The cylindricity C of the cylindrical lens 6 set in this way is displayed on the CRT 16 (step 114),
When the desired degree of cylindricity is achieved, the process proceeds to the next step (step 115). Next, AX data is input from the keyboard 15 (step 121), and the amount of rotation of the CC axis rotation motor 11 and the astigmatic rotation motor 9 is calculated in the calculation circuit 21 (steps 122 and 123). Based on these calculation results, the CC axis rotation motor 11 and the astigmatic rotation motor 9
is rotated, and the cylindrical axis of the cylindrical lens 6 is set at a desired angle, and the central axis of the CC lens 10 is set at the same axial angle as the cylindrical axis of the cylindrical lens 6 (steps 124, 125). Then, the set value of the C data is displayed on the CRT 16 (step 126), and when the value reaches the desired value, the process proceeds to the next step (step 127). Next, the CC lens 10 is set in the optical path (step 131), and the CC reversing motor 12 is rotated forward to
The A side (labeled A in FIG. 1) of the lens 10 is set on the front side (step 132). Thereafter, the CC reversing motor 12 is reversed to set the B surface (reference numeral B in FIG. 1) of the CC lens 10 to the front (step 133), and then the CC reversing motor 1
2 is rotated in the normal direction, and the A side of the CC lens 10 is set at the front (block 134). At this time, when the subject turns on the response switch 17 in a state where the sharpness is superior as a result of the comparison of sharpness (step 135), the CC axis reversing motor 11 is rotated in the normal direction and the CC lens is rotated forward. 10 intermediate shafts are rotated forward by a predetermined angle α (step 136)
At the same time, the astigmatic rotation motor 9 is rotated in the normal direction, and the axis of the cylindrical lens 6 is rotated in the normal direction by a predetermined angle α (step 137). When steps 136 and 137 are completed, the process returns to step 133. If the response switch 17 is not turned on in step 135, the B side of the CC lens 10, which is to be reversed by the CC reversing motor 12, is set to the front (step 141). As a result of the comparison of clarity, when the response switch 17 is turned on by the subject (step 142), the CC axis rotation motor 11 is rotated in the reverse direction.
The intermediate axis of the lens 10 is reversed by a desired angle α (step 143), and the astigmatic rotation motor 9 is reversed to reverse the axis of the cylindrical lens 10 by α (step 144). Thereafter, the CC reversing motor 12 is rotated in the normal direction to set the A side of the CC lens 10 at the front (step 145), and then the process of step 141 is performed. If the response switch 17 is not turned on in step 142, the CC axis rotation motor 11 is rotated, and the intermediate axis of the CC lens 10 is rotated by 45 degrees with respect to the axis of the cylindrical lens 6 (step 142).
151). Then, the CC lens reversing motor 12 is reversed.
After the B side of the CC lens 10 is set to the front (step 152), the CC lens reversing motor 12 is rotated in the normal direction to set the A side of the CC lens 10 to the front (step 153). At this time, as a result of the comparison of sharpness by the subject, the response switch 17 is turned on (step 154), and the astigmatism drive motor 8 is rotated to set the cylindrical lens 6 which is -0.25 stronger (step 155). ,
Return to step 152. As a result of the comparison of sharpness by the subject, if the response switch 17 is not turned on in step 154, the CC reversing motor 12 is reversed.
The B side of the CC lens 10 is set to the front (step 161). Here, when the response switch 17 is turned on (step 162), the astigmatism drive motor 8 is reversed and the cylindrical lens 6, which is weaker by -0.25, is selected (step 163). Then, the CC reversing motor 12 is rotated normally to set the A side of the CC lens 10 at the front (step 164), and the process returns to step 161. If the response switch 17 is not turned on in step 162, the data is displayed on the CRT 16 (step 165). As described above, the inspection target P is passed through the CC lens 10.
When comparing the sharpness before and after reversing the CC lens 10, if the test subject turns on the response switch 17 when the sharpness is superior, the following two things will happen. Step is executed. In the first step, the axis of the CC lens 10 and the cylindrical axis of the cylindrical lens 6 are rotated by a predetermined amount in a predetermined direction. In the second step, the axis of the CC lens 10 is separated from the cylindrical axis of the cylindrical lens 6 and rotated by 45 degrees, and then the sharpness is compared again before and after reversal, and the subject is examined in the superior state. When the response switch 17 is turned on, the cylindrical lenses 6 having different refractive powers are set. By sequentially executing these first and second steps by turning on one response switch 17, the astigmatism axis and degree of astigmatism can be tested easily and in a short time based on the test subject's responses. be able to. FIG. 4 is a block diagram of another embodiment of the present invention. The same elements as those in the embodiment shown in FIG. 1 are designated by the same reference numerals, and the driving motors for the far-near and far vision correcting optical system and the astigmatism correcting optical system are omitted. The difference from the embodiment shown in FIG. 1 is that two CC lenses 10a and 10b are provided, and a cross cylinder lens switching motor (hereinafter referred to as "CC switching motor") 40 is provided for switching between them. This is what is happening. FIG. 5 is an explanatory diagram of the arrangement of the CC lenses in FIG. 4. The two CC lenses 10a and 10b have the same optical characteristics and are arranged on the same radius with their axes shifted by 90° from each other. The axes of the CC lenses 10a and 10b are rotating gear rows 41 and 41'
The lens shaft is rotated by the CC lens shaft rotation motor 11 via the switching gear 42, and switched by the CC switching motor 40 via the switching gear 42. In this embodiment, when the test target P is viewed alternately through the CC lenses 10a and 10b and the sharpness is compared, if the response switch 17 is turned on by the subject in the superior state. , the following two steps are performed. In the first switch, the CC lenses 10a, 10
b axis and the cylindrical axis of the cylindrical lens 6 are rotated by a certain angle in a predetermined direction. In the second step, the CC lenses 10a, 10
After separating the axis of b from the axis of the cylindrical lens 6 and rotating it by 45 degrees, the two CC lenses 10a and 1 are connected again.
0b is compared, and when the response switch 17 is turned on in the superior state, the cylindrical lenses 6 having different refractive powers are set on the optical axis. By sequentially executing these first and second steps by turning on one response switch 17, the degree of astigmatism and axis of astigmatism of the subject can be tested easily and in a short time. FIG. 6 is an explanatory diagram of the arrangement of cross cylinder lenses according to still another embodiment of the present invention. As shown in the figure, two CC lenses 10c and 10 with the same optical characteristics
d are juxtaposed with a difference in cylinder axis of 90°, and the eye to be examined is 50
The test optotypes can be viewed alternately. FIG. 7 is an explanatory diagram of the subject response switch according to the embodiment of FIG. 6. Response switch 1 as shown
7' has two buttons, one of which is connected to the CC lens 10.
c and the other corresponds to 10d. In this way, the subject can see the two CC lenses 10c and 10c by slightly shifting their line of sight left and right.
The inspection can be carried out by comparing the superiority and inferiority of sharpness using CC lenses 10d and operating buttons corresponding to the superior CC lenses 10c and 10d.

【effect】

As explained above, the invention provides an astigmatism correcting optical system having a plurality of cylindrical lenses each having a different refractive power and rotatable around an optical axis, a cross cylinder lens rotatable around the optical axis, and a lens. The structure includes first and second lens rotation devices that rotate the cylindrical axis of the cylindrical lens and the axis of the cross cylinder lens by predetermined amounts, respectively, when the rotation operation switch is operated. During the rotational operation (rotation adjustment), the cross cylinder lens and the cylindrical lens can be rotated in relation to each other according to the test subject's response using a single switch. Moreover, as mentioned above, since the cross cylinder lens and cylindrical lens can be operated in conjunction with one switch, there is no possibility of misaligning the direction or amount of rotation of the cross cylinder lens or cylindrical shaft during astigmatism testing. Things will disappear. As a result, the astigmatism test can be easily performed and the time required for the astigmatism test can be shortened. Furthermore, there is no fear that incorrect test results will be produced due to incorrect alignment.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a control block diagram of the embodiment shown in Fig. 1, and Fig. 3 explains the operation of the embodiment shown in Figs. 1 and 2. Flowchart, FIG. 4 is a configuration diagram of another embodiment of this invention, FIG. 5 is an explanatory diagram of the arrangement of the cross cylinder lens in FIG. 4, and FIG. 6 is a cross cylinder of still another embodiment of this invention. FIG. 7 is an explanatory diagram of the arrangement of lenses, and FIG. 7 is an explanatory diagram of the subject response switch according to the embodiment of FIG. 6. 1... Spherical lens plate, 2... Spherical lens, 4,
7... Axis, 10, 10a to 10d... Cross cylinder lens (CC lens), 17, 17'... Subject response switch, P... Examination target.

Claims (1)

[Scope of Claims] 1. An astigmatism correcting optical system having a plurality of cylindrical lenses each having a different refractive power and rotatable around an optical axis, a cross cylinder lens rotatable around the optical axis, and a lens rotation operation. A visual acuity testing device comprising first and second lens rotation devices that rotate the cylindrical axis of the cylindrical lens and the axis of the cross cylinder lens by predetermined amounts, respectively, when a switch for the cylindrical lens is operated. 2. Claim 1, further comprising a driving device that drives the astigmatism correcting optical system and sequentially sets the cylindrical lenses having different refractive powers on the main axis when the switch is operated. vision testing device.