JPH0323043B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention projects a measurement optotype illuminated by a measurement light source having a wavelength in the infrared region onto the fundus of the eye in at least three meridian directions. The present invention relates to an objective refractive power measuring device (so-called autorefractometer) that detects a visual target image by a light receiving means and measures the objective refractive power of a subject's eye based on the detection result.

[Conventional technology]

As a device for measuring the refractive power of the eye for eyeglass adjustment, in recent years many automatic objective refractive power measurements have been used because the measurement time is fast, no skill is required for measurement, and there is little difference in measurement between examiners. A device has been proposed. Even when these devices are used, final adjustments are made using a subjective refractive power measuring device.

Therefore, in the past, it was common for the examiner and the subject to move to the subjective refractive power measuring device after the objective measurement and perform a new measurement from the beginning.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, two devices, an objective type and a subjective type, must be installed, which poses problems both in terms of cost and space.

Also, when moving to subjective measurement after objective measurement,
Since both the examiner and the subject must move, this is not only very troublesome, but also causes problems such as the measurement conditions changing.

Furthermore, even if the objective measurement itself is automated and the burden on examiners and subjects is greatly reduced, most of its effectiveness will be lost if the time required for subjective measurement cannot be shortened. An object of the present invention is to provide an objective eye refractive power measurement device that can perform both objective and subjective measurements with a single device and can significantly reduce the time required for subjective measurements.

[Means to solve the problem]

In order to achieve the above object, the objective eye refractive power measurement device of the present invention provides a measurement optotype illuminated by a measurement light source having a wavelength in the infrared region on the fundus of the eye in at least three meridian directions. In an objective refractive power measuring device that projects an eye target image, detects the projected target image by a light receiving means, and measures the objective refractive power of the eye to be examined based on the examiner's results, a fixation target projection system disposed at a position branched from the fixation target projection system; a visual target presentation unit for subjective optometry disposed in the fixation target projection system; and at least two
Spherical refractive power, cylindrical refractive power, and
a corrective optical system capable of changing the axial angle; a driving means capable of changing the spherical refractive power, cylindrical refractive power, and axial angle of the corrective optical system; and correction based on the objective refractive power measurement value. The present invention is characterized by comprising: an instruction switch that drives the optical system and presents an optometry target for subjective optometry to test an expected corrected visual acuity value.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is an optical system layout diagram of an optometry apparatus according to the present invention, and a combined objective and subjective apparatus in which a subjective optometrist is built into an objective automatic refractive power measurement apparatus will be described.

1 is a measurement light source with a wavelength in the infrared region, 2, 3
4 is a condenser lens; 4 is a movable spot diaphragm (measurement target; hereinafter simply referred to as a spot diaphragm); 5, 6;
is an objective lens, 7 and 9 are prisms, 10 is a mirror, 11 and 12 are relay lenses, and 13 is the eye to be examined 8
14 is a moving lens that moves together with the spot diaphragm 4, and 15 is an imaging lens. Reference numeral 16 denotes a measurement light receiving element, which rotates about the optical axis in synchronization with the measurement light source 1 and the corneal reflection removal mask 13. A first relay lens 17 is movable on the optical axis, and the amount of movement thereof is proportional to the spherical refractive power of the eye to be examined.

Reference numerals 18 and 19 are positive cylindrical lenses having the same focal length, and both lenses are rotatable about the optical axis by the same amount in the same direction or in opposite directions. Note that, as is well known, when creating a cylindrical component using two cylindrical lenses, it is necessary to take the spherical effect into account and make corrections.

20 is a second relay lens, 21 is an optotype plate located at the focal position of the second relay lens 20, and the fixation optotype and the general optotype (hereinafter, the optotype for visual acuity test is referred to as the general optotype) are the same. placed within the field of view. In this example, the fixation optotype and the general optotype are arranged on one optotype board, but the
45551 (Japanese Patent Application Laid-Open No. 53-130891) As described in the specification of "Optometry device", it is a rotating disk on which optotypes are arranged at intervals in the circumferential direction,
It goes without saying that the disc may be rotated to insert different types of optotypes into the optical path.

22 is a condensing lens, and 23 is an illumination lamp.

Figures 2 and 3 show other embodiments of the target optical system, and 18a and 19a in Figure 2 are positive cylindrical lenses with equal focal lengths, and both rotate around the optical axis. It's becoming possible. In FIG. 3, 18b is a positive cylindrical lens which is movable on the optical axis. 19b indicates a negative cylindrical lens;
It is adapted to rotate around the optical axis together with the positive cylindrical lens 18b. Furthermore, both of these cylindrical lenses and the first relay lens are movable together on the optical axis.

Figure 4 shows the first relay lens 17 in the optotype optical system.
2 is a block diagram showing a path for operating the cylindrical lenses 18 and 19. Reference numeral 24 is a dial provided on the side of the body (not shown), and is adapted to generate a pulse signal by rotation of a rotary encoder. 25 is a pulse counter, 26 is a microcomputer that controls all operations related to objective and subjective measurement, 27 is a display, 28 is a pulse motor driver, and 29 is a cylindrical lens 18, 19.
30 is a D/A converter for converting a digital signal into an analog signal; 30 is a D/A converter for converting a digital signal into an analog signal;
1 is a DC motor for moving the first relay lens 17 along the optical axis to change the spherical refractive power, and 32 is an A/D converter.

The operation of the apparatus configured as above will be described below.

Objective measurement Infrared light emitted from light source 1 is transmitted through condensing lenses 2 and 3.
The light passes through a spot diaphragm 4 and an objective lens 5, and is focused on the eye 8 and cornea to be examined, and reaches the fundus of the eye. On the other hand, the light from the illumination lamp 23 passes through the condenser lens 22 and passes through the optotype plate 2.
Projecting the fixation target in 1 onto the fundus of the eye to be examined 8,
The subject's eye 8 is fixed. The light reflected from the fundus of the eye is reflected by a mirror 10, passes through relay lenses 11 and 12, and then forms an image on a light receiving element 16 by an imaging lens 15. The light receiving element 16 detects the incident light, and the microcomputer 26 moves the spot diaphragm 4 and the movable lens 14 until the spot diaphragm 4 is at a position conjugate with the fundus of the eye 8 to be examined. At the same time, after the fixation target is imaged on the fundus of the eye 8 to be examined, the first eye is placed so that it is fogged by an appropriate diopter.
Move the relay lens 17.

After that, a measurement light source 1, a corneal reflection removal mask 1
3 and the measuring light receiving element 16 are rotated 180° around the optical axis. During rotation, the refractive power value for each meridian can be known from the signal from the light receiving element.

Subjective Measurement After the above-mentioned other measurements are completed, when the subjective measurement changeover switch (not shown) is pressed, the first relay is switched to the position of the value obtained in the objective measurement under the control of the microcomputer 26. Lens 17 moves and cylindrical lenses 18 and 19 rotate, respectively.
Therefore, the eye 8 to be examined sees the general optotype with the refractive power obtained by objective measurement corrected. Even in this state, if the target cannot be used as an optotype to test the corrected visual acuity value, for example, the Landolt ring, which corresponds to a visual acuity value of 1.0 among the general optotypes, perform subjective measurement using the following manual operation. . Measurements are made of spherical refractive power, cylindrical refractive power, and axial angle.

When measuring spherical refractive power, when the spherical refractive power measurement switch is pressed and the dial 24 is rotated, a pulse signal generated by the rotation of the rotary encoder is inputted to the microcomputer 26 by the counter 25, and is input to the A/D converter. through 30
The DC motor 31 operates to move the first relay lens on the optical axis, creating a refractive power corresponding to the amount of rotation of the dial 24.

Similarly, when measuring the cylindrical refractive power, press the cylindrical refractive power measurement switch, and when measuring the axial angle, press the axial angle measurement switch, rotate the dial 24, and the computer 2
6 operates the pulse motor 29 to rotate the cylindrical lenses 18 and 19.

The dial 24 is rotated, for example, by 2 degrees to generate pulses, and the pulses are set to correspond to 0.25D for the spherical and cylindrical refracting powers, and 1 degree for the axial angle. As the dial 24 is rotated, the refractive power value is also displayed on the display 27.

2 and 3 show other embodiments of the target optical system, but the operation in FIG. 1 is exactly the same as that in FIG. 1.

In the optical system shown in Fig. 3, the DC motor 3
1, the first relay lens 17 and the cylindrical lens 18
b and 19b are moved together to set the spherical refractive power, and the cylindrical lens 18b is moved to set the cylindrical refractive power. Further, the cylindrical lenses 18b and 19b are rotated together by the pulse motor 29 to set the axial angle. In the above embodiment, the first relay lens is moved, but the same effect can be obtained by moving other optical elements in the optotype optical system, such as the second relay lens, optotype, etc. can get.

Furthermore, although the dial type has been described, it goes without saying that other types may be used.

[Effects of the Invention] According to the present invention, precise subjective measurement can be performed with one device without adversely affecting the objective measurement optical system, so the device can be very advantageous in terms of cost and space. did it.

During subjective measurement, the corrective optical system is automatically set based on the objective measurement value, and an optotype to test the expected corrected visual acuity value is also presented at the same time, significantly shortening the time required for subjective measurement. .

[Brief explanation of the drawing]

FIG. 1 is an optical system layout diagram of the objective and subjective optometry apparatus according to the present invention, FIGS. 2 and 3 are optical system layout diagrams showing other embodiments of the visual target optical system, and FIG. It is a block diagram. 24...Dial, 25...Pulse counter,
26...Microcomputer.

Claims (1)

[Scope of Claims] 1. A measurement optotype illuminated by a measurement light source having a wavelength in the infrared region is projected onto the fundus of the eye in at least three meridian directions, and the projected optotype image is detected by a light receiving means. In an objective eye refractive power measurement device that measures the objective refractive power of the subject's eye based on the detection result, a fixation target projection system is placed at a position branched from the optical axis of the measurement optical system. and a visual target presentation unit for subjective optometry disposed in the fixation target projection system; and at least two visual target presentation units disposed in the fixation target projection system.
Spherical refractive power, cylindrical refractive power, and
a correction optical system capable of changing an axial angle; a driving means capable of changing spherical refractive power, cylindrical refractive power, and axial angle of the corrective optical system; and correction based on the objective refractive power measurement value. An objective eye refractive power measuring device comprising: an instruction switch that drives an optical system and presents an optotype for subjective optometry to test an expected corrected visual acuity value.