JPH0363028A - Apparatus for ophthalmic measurement - Google Patents

Abstract

PURPOSE:To confirm reliability of measured result easily by installing an operation part, which computes and processes a corneal shape and an ophthalmic refractive power from respective informations on reflection images of the cornea and eye ground, and a monitor part, which displays the reflection images of the cornea and eye ground from respective image informations. CONSTITUTION:An operation part 301A computes and processes subject eye's corneal shape and ophthalmic refraction power from informations on reflection images 100'' and 203'' of the cornea and eye ground memorized in frame memories 324 and 325, respectively. A monitor part 305 displays the reflection images of the cornea and eye ground based on respective image informations, which are memorized in the frame memory part and used for computation and processing. It is possible, by using this method, to call the reflection images of cornea and eye ground, which are the bases for computing measured values of corneal shape and ophthalmic refraction power, respectively, from the frame memory part and to observe them on the same monitor, even after these measured values have been computed from respective image informations memorized in the frame memory part. It is possible, therefore, for a measurer to judge easily whether a measured result is reliable or not, resulting in improving reliability of the measured result.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in an ophthalmological measuring device for measuring the corneal shape and eye refractive power of an eye to be examined.

(Prior art) Conventionally, each index image is projected onto the cornea and the fundus of the eye to be examined, and the corneal reflection image and the fundus reflection image of the eye to be examined formed by the projection of each index image are received by a light receiving section. A device that stores an image signal output from a light receiving unit in a frame memory as image information of a corneal reflection image and a fundus reflection image, and measures the corneal shape and ocular refractive power of the eye to be examined based on the image information stored in the frame memory. It has been known.

(Problems to be Solved by the Invention) By the way, this type of ophthalmological measuring device reads image information stored in a frame memory and calculates the corneal shape and eye refractive power of the eye to be examined based on the image information. However, the corneal reflection image and the fundus reflection image, which are the basis of this calculation, were not configured to be displayed as images.

Therefore, with this conventional ophthalmological measuring device, even if a measurement result that appears to be an abnormal value occurs and the operator has doubts about the measurement result, the cornea used as the basis for the calculation to obtain the measurement result is It was not possible to observe the reflected image and the fundus reflected image themselves, and it was difficult to judge whether the corneal reflected image and the fundus reflected image were of a level that could be recognized as appropriate for measurement. Therefore, there was a problem in that the reliability of the measurement results was insufficient.

(Object of the Invention) The present invention has been made in view of the problems of the above-mentioned prior art, and includes a corneal reflection image and a fundus reflection image, which are the basis for calculating the corneal shape and eye refractive power of the eye to be examined. It is an object of the present invention to provide an ophthalmological measuring device that can be used to observe itself later and easily confirm the reliability of the measurement results.

(Means for Solving the Problems) The ophthalmological measurement device according to the present invention is characterized by projecting each index image onto the cornea and fundus of the eye to be examined, and the corneal reflection image and fundus reflection of the eye to be examined formed by the index images. a measurement system that projects an image onto a light receiving section; a frame memory section that stores the corneal reflected image and the fundus reflected image as image information based on the image signal output from the light receiving section; and a cornea stored in the frame memory section. a calculation processing unit that calculates the corneal shape and eye refractive power of the eye to be examined based on image information of the reflected image and the fundus reflection image; and a calculation processing unit that calculates the corneal reflection based on each image information stored in the frame memory unit and used for calculation processing. It consists of a single monitor section that displays the image and the fundus reflection image.

(Function) According to the ophthalmological apparatus according to the present invention, even after obtaining the corneal shape measurement value and the eye refractive power measurement value as measurement results by calculation using the image information stored in the frame memory section,
The corneal reflection image and the fundus reflection image, which are the basis for calculating the corneal shape and eye refractive power, can be recalled from the frame memory section and observed on the same monitor. Therefore, the measurer can visually and intuitively observe the corneal reflection image and the fundus reflection image with the naked eye to determine whether the measurement results are reliable or not, and whether re-measurement is necessary or not. It is possible to easily determine whether the

(Example) I-A. Overall optical arrangement FIG. 1 shows the overall optical arrangement of the measurement system of the ophthalmological measuring device according to the present invention. This optometry device is the eye to be examined.
a keratometry system 1 for measuring the radius of curvature of the cornea C;
An objective refractive power measurement system 2 for objectively measuring the refractive power of the eye to be examined E, and a fixation projection that projects a fixation target onto the eye to be examined to fix the visual axis of the eye to be examined during measurement. The system 3 generally comprises an anterior eye segment observation/alignment system 4 that observes the anterior segment of the eye E to be examined and aligns the optical axis of the device with the visual axis of the eye E to be examined. Note that a part of the optical path of the anterior segment observation/alignment system 4 is shared with the optical path of the keratometry system l.

1-B, Keratometric System 1 The keratometric system 1 includes a pattern projection system 10 that projects an annular pattern toward the cornea as an index image for measuring the radius of curvature of the cornea, and a corneal reflection image of the annular pattern. and a measuring optical system 11 for measuring the size and shape of.

The pattern projection system 10 includes a pattern plate 101 having an annular aperture 100 and a circle disposed behind the aperture 100 that emits keratometry light with a wavelength of 930 nm to 11000 nm (hereinafter, this keratometry light will be denoted by the symbol a). Annular light source 102
It is composed of. The emitted light from the annular light source 102 passes through the aperture 100 and is projected onto the cornea C of the eye E to be examined as projection light. The projected light is reflected by the cornea C, and the aperture 1
Create a virtual image 100' of 00. The keratometry light a reflected by the cornea C enters the measurement optical system 1 as if it had emitted a virtual image 100'.

The measurement optical system 11 includes an objective lens 110 and a wavelength of 400n.
Visible light with a wavelength of m to 700 nm (hereinafter referred to as C) is reflected and keratometry light a (with a wavelength of 930 nm to 1
A half mirror 111 that transmits light in a long wavelength range of 800 nm or more including 01000 nm, and a half mirror 111 with a wavelength of 865 nm.
a half mirror 112 that transmits infrared light (hereinafter referred to as "infrared light") and reflects infrared light with a wavelength of 900 nm or more, a relay lens 113, and an aperture 114;
A half mirror 115 that transmits red light with a wavelength of 700 nm (hereinafter referred to as the red light) and reflects the keratometry light a, a relay lens 116, and a relay lens 116 that reflects the infrared light and reflects the keratometry light a. It is generally composed of a half mirror 117 that transmits the and red light d, an imaging lens 118, and an area CCD 5 as a light receiving section.

Here, as shown in FIG. 3, the diaphragm 114 is
It is divided into two parts: 14a and a central part 114b. Peripheral area 1
14a cuts light with a wavelength of 930 nm or more, and the central part 1
14b is configured to transmit light having a wavelength of 900 nm or more. That is, light of 900 nm or more and 930 nm or less (hereinafter, this light will be denoted by the symbol e) can be transmitted through the entire area of the aperture 114. After the keratometry light a reflected by the cornea C is focused by the objective lens 110,
It passes through the half mirror 111. Then, the keratometry light a is reflected by the half mirror 112, and the relay lens 1
13 and passes through the center portion 114b of the diaphragm 114.

Thereafter, the keratometry light a is reflected by the half mirror 115, and is transmitted to the half mirror 11 by the relay lens 116.
7 and pass through its half mirror 117.

The keratometry light a is focused on the area CCD 5 by the imaging lens 118, and a ring pattern image 100# (see FIGS. 6 and 7) is formed as a corneal reflection image. Although the aperture 114 has the function of forming the ring pattern image 100'' in the center of the area CCD 5, it may not be provided for the same reason as the aperture 215, which will be described later.

Even if the anterior segment (iris) of the subject's eye is illuminated when forming the virtual image 100' of the aperture 100 by projecting the keratometric light a,
Since the reflected light is cut off by the peripheral portion 114a of the aperture 114, it does not reach the area CCD 5, and only the ring pattern image 100# is projected onto the area CCD 5.

rc, objective refractive power measurement system 2 C-1: Pattern projection system 20 FIG. 2(a) is an optical path diagram of the pattern projection system 20 shown in FIG. Wavelength 8 emitted from light emitting diode 200
The 65 nm refractive power measurement light (infrared light b described above) is condensed by a condenser lens 201 and then passed through a conical prism 20.
2, and is irradiated onto a ring pattern 203 for measuring refractive power. The refractive power measurement light that has passed through the ring pattern 203 is irradiated onto the ring diaphragm 207 via the relay lens 204, the mirror 205 (see Figure 2), and the relay lens 206. After the refractive power measurement light passes through the ring diaphragm 207, it is reflected by the reflective surface 208a of the perforated mirror 208. Thereafter, the refractive power measurement light is reflected by the mirror 209, passes through the half mirrors 112 and 111 as components of the measurement optical system 11 of the keratometry system 1, and is directed to the fundus ER of the eye E by the objective lens 110. An index image 203' (see FIG. 2) based on the ring pattern 203 is projected. Here, a light emitting diode 200 and a ring aperture 2
07 is optically conjugate, and the ring aperture 207
and the pupil Eρ of the eye E to be examined are in an optically conjugate position.

C-2: Measurement optical system 21 FIG. 2(b) is an optical path diagram of the measurement optical system 21 shown in FIG. 1. The refractive power measurement light beam, which is the reflected light of the index image 203' based on the ring pattern 203 reflected by the fundus ER of the eye E, is focused by the objective lens 110.

The refractive power measurement light is a half mirror 111,1.
12, is reflected by mirror 209, passes through opening 208b of perforated mirror 208, and is guided to diaphragm 210. The refractive power measurement light passes through the diaphragm 210 and the relay lens 211, is reflected by the half mirror 212 that transmits visible light C, and is irradiated onto the diaphragm 215 via the relay lens 213 and mirror 214. This aperture 2
As shown in FIG. 4, the lens 15 has a peripheral portion 215b through which a refractive power measuring beam having a wavelength of 865 nm is transmitted, and a central portion 215a which cuts off the refractive power measuring beam.

Moreover, this aperture 215 has a wavelength of 93
The keratometric light a of 0 nm to 11000 nm is not transmitted,
Moreover, it has a property of transmitting visible light C having a wavelength of 400 nm to 700 nm. As a result, the refractive power measurement light is changed to the diaphragm 21.
After passing through the half mirror 217 which reflects only the visible light C through the focusing lens 216 and transmits the refractive power measuring light C, the visible light C passes through only the peripheral part 215b of the corneal measurement system 1 of the keratometry system 1. It is reflected by the half mirror 117, and is imaged on the area CCD 5 by the imaging lens 118,
A ring pattern image 203# (see FIGS. 6 and 7) is formed as a fundus reflection image. Note that the diaphragm 215 forms a ring pattern image 20 (described later) on the periphery of the area CCD 5.
Although it has the function of forming the ring pattern image 203# and the ring pattern image 100'' at the same time in the area CCD 5, it is not necessary to provide it.

The focusing lens 216 and the aperture 215 are part of the pattern projection system 20
The light emitting diode 200, the condenser lens 201, the conical prism 202, and the ring pattern 203 are housed in a movable housing 219, and are movable in the optical axis direction as shown by an arrow 218 in FIG. .

In the measurement optical system 21 described above, the diaphragm 210 is optically conjugate with the position of the pupil Ep of the eye E to be examined with respect to the objective lens 110, and the area CCD 5 is the same as the position of the pupil Ep of the eye E to be examined when the eye E is emmetropic (refractive power ODiopter). ring pattern 2
It is optically conjugate with the intermediate imaging plane A of 03 (see FIG. 2).

ID, fixation projection system 3 wavelength 400 nm to 700 nm emitted by light source 30
Visible light C of m is condensed by a condenser lens 31 and illuminates a fixation chart board 32.

The image of the fixation chart board 32 is projected onto the eye E by the projection lens 35, and after being reflected by the mirror 36,
It is reflected by the half mirror 217, joins the measurement optical system 21 of the objective refractive power measurement system 2, passes through the aperture 215 via the focusing lens 216, and then passes through the mirror 214 and the relay lens 213.
is guided to the half mirror 212 through the half mirror 2
12, barrier pull cross cylinder (VCC)
37. The visible light C passes through the barrier pull cross cylinder 37 and passes through the mirror 38 to the half mirror 1.
11 and projected onto the subject's eye E by the objective lens 110, and the fixation chart board 32 is observed by the subject's eye.

I-E, A plurality of light emitting diodes 40 for illuminating the anterior ocular segment are arranged outside the pattern plate 101 of the pattern projection system IO of the anterior ocular segment observation and alignment keratometry system 1, and each light emitting diode 40 emits light. wavelength 900
nm infrared light (hereinafter, this infrared light is given the symbol e),
The anterior segment of the eye E to be examined is illuminated. The infrared light e reflected by the anterior segment of the eye (anterior segment illumination light) is focused by the objective lens 110, passes through the half mirror 111, and is transmitted along the measurement optical system 11 of the keratometry system 1 described above. and is imaged onto the area CCD 5 by the imaging lens 118.

A plurality of light emitting diodes 41 that emit infrared light with a wavelength of 900 nm are arranged near the outer periphery of the objective lens 110, and these light emitting diodes 41 serve as a light source for alignment. Alignment light emitted from this alignment light source 41 (hereinafter, the symbol f is attached to this alignment light)
is subject 11! After being reflected by E, the light is focused by the objective lens 110, and is sent to the half mirror 11 in the same way as the anterior segment illumination light e.
1, it is propagated along the measurement optical system 11 of the keratometry system 1, and is imaged onto the area CCD S by the imaging lens 118.

In front of the half mirror 115 of the measurement optical system 11 of the corneal measurement system 1, an aiming scale projection optical system is arranged. This aiming scale projection system uses red light with a wavelength of 700 nm (
This corresponds to the aforementioned light d. A light emitting diode 42 that emits scale light (hereinafter referred to as scale light), a condensing lens 43 that focuses the scale light source from the light emitting diode 42, and a measuring optical system 1 that reflects the scale light that has passed through the aiming scale 44.
1 and a mirror 45 for merging the two.

The scale light source from the aiming scale 44 is a half mirror.
After passing through the measurement optical system 11, it is imaged onto the area CCD 5 by its imaging lens 118.

(2) Electric circuit configuration FIG. 5 is a block circuit diagram of this ophthalmological measuring device. The drive circuit 313 scans the area CCD 5 in response to a command from the arithmetic/control circuit 301, and outputs an image signal thereof.

The arithmetic/control circuit 301 controls the gate circuit 302, and the gate circuit 302 converts the image signal from the area CCD 5 into A
/D converter 303 or display interface 3
Output toward 04. The display interface 304 connects the area CCD via the gate circuit 302.
For example, a CRT receives an image signal from a CRT.

The image formed in the area CCD 5 is displayed on a display device 305 as a monitor section consisting of a liquid crystal television or a plasma display.

The A/D converter 303 has a function of converting the image signal from the area CCD 5 into a digital signal, and the digital signal is input to the arithmetic control circuit 301.

Frame memories 325 and 324 are connected to the arithmetic control circuit 301 and store image information for one screen or several screens of the area CCD 5 converted into digital signals by the A/D converter 303 as data. A ring pattern image 100'', which is the basis for corneal measurement, and a ring pattern image 203'', which is the basis for objective refractive power measurement, are stored in each frame memory 324 and 325, respectively. Also,
The arithmetic control circuit 301 has a function of selectively supplying pulses from the pulse generator 312 to the driver circuits 318, 319, and 320, counts the number of pulses, and outputs the counted value as a signal to the first memory 309. This first memory 309 stores the counted value.

A driver circuit 318 applies pulses from the arithmetic control circuit 301 to a pulse motor 3 for driving the moving wave body of the refractive power measurement system 2.
21 to drive this pulse motor 321. The driver circuit 319 supplies pulses to a pulse motor 322 for rotating the chart board 32 of the fixation projection system 3 to drive the pulse motor 322 . The driver circuit 320 supplies pulses to a pulse motor 323 for rotating the barrier pull cross cylinder (VCC) 37, and drives the pulse motor 323.

The calculation/control circuit 301 also includes driver circuits 314 to 314.
317.325.326 are connected. The driver circuit 314 is connected to the annular light source 102 of the keratometry system 1, and supplies power to the annular light source 102 by a power supply circuit (not shown) based on a command from the arithmetic/control circuit 301. Light emitting diode 2 of measurement system 2
00 is supplied based on a command from the calculation/control circuit 301.

The driver circuit 316 is the anterior segment observation/alignment system 4
The driver circuit 317 is connected to the anterior eye illumination light source 40 , the driver circuit 325 is connected to the alignment light source 41 , and the driver circuit 325 is connected to the aiming scale light source 42 , and the power supply to these is also based on commands from the calculation/control circuit 301 . Let's do it. Note that the driver circuits 316, 317, and 325 are operated by a common command from the arithmetic and control circuit 301, and the light sources 40, 41, and
．． 42 is configured to turn on and light at the same time.

Further, the driver circuit 326 is connected to the light source 30 of the fixation projection system 3, and the control circuit 301 controls the power supply to the light source 30.
This is done based on the directives of

Further, the arithmetic control circuit 301 includes a second memory 31 that stores the measured axis angles of the strong and weak principal meridians and each radius of curvature.
0, spherical power, cylindrical power, based on the measured refractive power,
A third memory 311 that stores the axial angle is connected to each of them. Note that the measurement of the axial angles of the strong and weak principal meridians, each radius of curvature, the spherical power, the cylindrical power, and the axial angle based on the refractive power will be described later.

Further, the arithmetic/control circuit 301 is connected to a program memory 307 storing a program for arithmetic/control, and a control switch 308 having various switches for starting measurement, etc. Memory 310. A character circuit 306 that converts the measurement data stored in 311 into characters and numbers and outputs them to the display interface 304.
is also connected to the calculation/control circuit 301.

Further, a mode setting switch 326 and a display changeover switch 327 are connected to the calculation/control circuit 301. The mode setting switch 326 is a switch for setting one of the keratometric mode, objective refractive power measurement mode, and keratometry/objective refractive power measurement mode, and automatically according to the mode selected by this mode setting switch 326. The 1 display changeover switch 327, on which measurement is performed, switches between the frame memory 324 and the frame memory 3 as described later.
Ring pattern image 203 “100” stored in 25
It has a function of displaying on the display 305.

(2) Measurement procedure and operation 1) The alignment examiner turns on the power switch (not shown) of the control switch 308. Then, the calculation/control circuit 304
Driver circuit by 316.317.325.326
is activated, light sources 40141. 42.30 will be lit at the same time.

At the same time, the drive circuit 313 is controlled by the arithmetic/control circuit 301.
is activated, thereby scanning the area CCD 5.

At this time, the arithmetic/control circuit 301 switches the gate circuit 302 so that the image signal from the area CCD 5 is sent to the display interface 304. As a result, the anterior segment of the eye E to be examined is illuminated with the light e from the light source 40, the alignment light f from the alignment light source 41 is reflected at the anterior segment, and both lights e and f are illuminated by the keratometry system l.
is guided onto the area CCD 5 through the measurement optical system 11, and an alignment index image is formed in the area CCD 5 together with the anterior segment image.

On the other hand, an image of the aiming scale 44 is formed in the area CCD 5 by the aiming scale light d. These three images are converted into image signals by the area CCD 5 and output, and the image signals are sent to the display interface 30.
4 to the display 305. by this,
As shown in FIGS. 9(a) and 9(b), the display 305 displays an anterior segment image, an aiming scale image 44', and an alignment index image 4.
1' is displayed as an image. Note that, instead of the light source 41, a spot projection optical system is provided in which a spot projected image is reflected from the corneal vertex, and the spot projected image is formed on the light receiving element 5. The bottom of the groove may be used to determine whether the alignment is successful or not based on whether or not it is within a predetermined range.

The subject visually recognizes the fixation chart board 32 illuminated by the light source 30 via the fixation projection system 3, which is partially shared with the refractive power measurement system 2. E
The visual axis of is fixed.

When the alignment index image 41' is outside the aiming scale image 44- as shown in FIG. 9(a), the measurer places the alignment index image 41' (see FIG. 9(b)) inside the aiming scale image 44'. ) is moved vertically and horizontally to align the optical axis of the eye E and the optical axis of the objective lens 110. Further, the entire optical system of the apparatus is moved back and forth to adjust the working distance to a normal distance so that the anterior segment image EA becomes a clear image.

2) Rough measurement of refractive power When the alignment is completed, the measurer sets the mode using the mode setting switch 326, and then turns on the measurement start switch (not shown) of the control switch 308. In the following description, a case will be described in which the objective refractive power/keratometry measurement mode is selected, in which the measurement of the objective refractive power and the measurement of the corneal radius of curvature are performed continuously.

Based on the command, the arithmetic/control circuit 301 stops issuing commands to the driver circuits 316, 317, and 325, and the light sources 40.
41.42 will be cleared for a short period of time. However, the command to the driver circuit 326 continues, and the light @30 continues to be lit.

The arithmetic/control circuit 301 instructs the driver circuit 315 to operate during the regular period of the light sources 40, 41, and 42 to turn on the light emitting diode 200. As a result, a finger IiJ image 203' formed by the ring pattern 203 is projected onto the fundus ER of the eye E to be examined, and the fundus reflected light of this index image 203' is projected onto the area CCD 5 via the measurement optical system 21.

At the same time, the arithmetic/control circuit 301
2, the image signal from area CCD 5 is converted to A/D.
It is input to converter 303. After that, calculation/control circuit 3
01 activates the drive circuit 313, the area CCD 5 is scanned, and the image output of the ring pattern image 203'' is output from the A/D.
It is output to converter 303. The A/D converter 303 A/D converts the image signal from the area CCD 5, and the digital signal is output to the frame memory 324 via the arithmetic/control circuit 301, and the ring pattern image 203 is stored in the frame memory 324. ” Information for one screen is stored.

Next, the arithmetic/control circuit 301 operates on this frame memory 32.
The size of the ring pattern image 203'' in the - meridian direction is detected based on the image signal of the ring pattern image 203# stored in 4, and the approximate refractive power of the eye E to be examined is calculated.

Based on this calculation, the calculation/control circuit 301 outputs a command signal to the driver circuit 318, supplies pulses from the pulse generator 312 to the pulse motor 321, and operates the movable housing section 2.
Move 19. Although the focusing lens 216 is moved by this movement of the movable housing section 219, the fixation chart 32a observed by the subject iE through the fixation projection system 3 is +1. It is set to be in a fog vision state of 0 to 2.0D.

The number of pulses supplied to the pulse motor 321 to move the movable housing section 219 is determined by the calculation/control circuit 30.
1 is counted by a counting circuit, and the counted value is sent to the movable housing part 2.
This is stored in the first memory 309 as a movement amount of 19.

3) The corneal curvature radius measurement and objective refractive power precise measurement control circuit 301 moves the movable housing section 219 based on the above rough measurement.
After moving, the light source 200 is turned on to store a ring pattern image 203# for accurate measurement in the frame memory 324. Note that, as a result, the ring pattern image 203' stored for rough measurement is erased. next,
The movable housing section 219 is moved and set to correspond to the refractive power of the eye E to be examined. With this setting, the subject can observe the fixation chart 32a in focus during corneal measurements described below.

Next, the light emitting diode 200 is turned off, and the annular light source 10 is turned off.
2 is caused to emit light, and the ring pattern image 100'' is stored in the frame memory 325.Then, the following calculation is performed.

First, based on the data in the frame memory 325, as shown in FIG.
i,... Gi,... Do GI+ and get the point on the ring pattern 1゜O"kg11kg2s...kgl
Obtain the coordinates of s...kgf,...kgn. Similarly,
Points Rg+, Rg2 N on ring pattern image 2o3#
... *g+, ... R21% ... Obtain the coordinates of Rgn.

3-1) Corneal curvature radius measurement calculation control circuit 301 calculates the obtained points kg+, kg2, .
Calculate the elliptical shape of the ring pattern image 100'' from the coordinates of... kg+,... kgl,... kgn.The radius S of the long axis (Xk axis) of the ellipse 1oo'' is the angle yt, c
The radius of curvature S, k of the minor axis (Yk axis) is correlated with the radius of curvature R2 of the minor principal meridian, and the angle θ of the major axis is 1 and the angle θ of the minor axis is 2. correspond to the axial angle Gi of the Hosochi meridian and the axial angle θ2 of the weak principal meridian, respectively.

The general formula for an ellipse 100'' in the Xk-Yk coordinate system is A
X2+BY2+CXY=1 (1).

Furthermore, the radius Sk of the ring pattern image 100'' is determined by using the radius of curvature of the cornea C as R, as shown in FIG.
0, the working distance is 1, and the magnification of the entire projection optical system is β.Therefore, in the example shown in Figure 7, from equations (1) and (2), S 1
Find S and k, and use equation (3) to find the radius of curvature R1 of the Hosodo meridian.
can be found as

Further, the axis angle θ1 of the Hosochi meridian is calculated as θ2, and the axis angle θ2 of the weak principal meridian is calculated as θkl. The radii of curvature R1, R2 and axis angles θ1, θ2 thus obtained are displayed together with the anterior segment image on the display 305 as shown in FIG. 9(b) via the character circuit 306 and display interface 304. and stored in the second memory 310.

3-2) Point Rglq Rg2S"'RglN1' Rg of the ring pattern image 203s obtained by the objective refractive power measurement readout scan
ls... Based on the coordinates of Rgn, the above formula (1),
Similarly to equation (2), the ellipse 2 at the X R-Y R coordinates
The general formula of 03# is Ax2+By2+Cxy=1
(1) The radius of curvature R2 of the weak principal meridian is similarly expressed as.

From equations (1) and (2) in 2, S XRN S V R
Find the refractive power Dl of the principal meridian and the refractive power D of the East German principal meridian.
2 is a ring pattern image 20 of emmetropia (ODioptpr)
If the radius of 3# is r, then in the example shown in FIG. 7, it is determined as follows. Here, f is the composite focal length of the measurement optical system 21, and X is the base line length (that is, the radius of the conjugate image of the ring diaphragm at the pupil position of the eye to be examined).

Next, the arithmetic/control circuit 301 reads out the amount of movement of the movable housing section 219 stored in the first memory 309, that is, the number of pulses corresponding to the amount of movement of the focusing lens 216, and from this number of pulses, the focusing lens The refractive power correction valve d due to the movement of 216 is added to the refractive powers D + and D 2 of the strong and weak main meridians determined by the above equation (5), and (D + + d )
, find (D2+d). As a result, the spherical refractive power 81, the cylindrical refractive power 01, and the cylindrical axis angle θ of the eye to be examined are determined as follows. The arithmetic/control circuit 301 causes the obtained S, C, and θ to be displayed on the display 305 via the character circuit 306 and the display interface 304, and is also stored in the third memory 311.

Some of the measurement results obtained in this way seem to be abnormal values, and in order to use them as the basis of calculations, the frame memory
Ring pattern image 100' stored in 04.305,
When it is desired to display 203# on the display 305, the display changeover switch 327 is operated.

The display changeover switch 327 is, for example, a push button type, and when the display changeover switch 327 is pressed once,
The arithmetic/control circuit 301 reads image information corresponding to the fundus reflection image from the frame memory 324, and displays the tenth ring pattern image 203# as the fundus reflection image on the display 305.
Display it as shown in the figure. In other words, the display 305 changes from the state where the measurement results are displayed to the ring pattern image 203.
The state changes to display #. Next, when the display changeover switch 327 is pressed again, the calculation/control circuit 327
1 reads the image information corresponding to the corneal reflection image from the frame memory 325, and a ring pattern image 100'' as the corneal reflection image is displayed on the display 305 as shown in FIG. When pressed again, the display 305 returns to displaying the original measurement results.

In this embodiment, the corneal reflection image and the fundus reflection image are selectively displayed on the display 305. By operating the display changeover switch 327, the corneal reflection image and the fundus reflection image are displayed on the display 305 as shown in FIG. Ring pattern image 100" as an image
It is also possible to have a configuration in which the ring pattern image 203# as the fundus reflection image is displayed simultaneously.

(Effects of the Invention) As explained above, according to the ophthalmological measuring device according to the present invention, the corneal shape measurement value and the eye refractive power measurement value are calculated as measurement results using the image information stored in the frame memory section. Even after the corneal shape and refractive power are calculated, the corneal reflection image and fundus reflection image, which are the basis for calculating the corneal shape and refractive power, can be recalled from the frame memory and the corneal reflection image and fundus reflection image themselves can be graphically and intuitively displayed. This has the effect that the measurement can be observed with the naked eye on the same monitor, and therefore the person taking the measurement can easily determine whether or not it is necessary to perform the measurement again, which has the effect of increasing the reliability of the measurement results. .

[Brief explanation of drawings]

FIG. 1 is a diagram showing the entire optical arrangement of the measurement system of the ophthalmological measurement device according to the present invention, and FIG. 2 is an optical path diagram of the objective refractive power measurement system.
3 is a plan view of the aperture 114, FIG. 4 is a plan view of the aperture 215, FIG. 5 is a block diagram showing the configuration of the electric circuit, and FIG.
The figure shows the relationship between area COD and ring pattern image.
Figure 7 is a schematic diagram for explaining the principle of measuring corneal radius of curvature and eye refractive power from a pattern system, Figure 8 is a diagram for explaining the principle of measuring radius of curvature, Figures 9(a), 9. (b) is a diagram showing the display state of the display, and FIGS. 10 to 12 are diagrams each showing the display state of the corneal reflection image and the fundus reflection image on the display. 1... Keratometry system, 2... Objective refractive power measurement system, 5.
...Area CCD (light receiving section) 100#...Ring pattern image (corneal reflection image) 203
#...Ring pattern image (fundus reflection image) 301...
Arithmetic/control circuit, 305...display device (monitor 327/
・Display changeover switch 324.325 ・Frame memory

Claims (3)

[Claims] (1) A measurement system that projects each index image onto the cornea and fundus of the eye to be examined, and projects the corneal reflection image and fundus reflection image of the eye to be examined, which are formed by the projection of the respective index images, onto a light receiving unit; a frame memory section that stores the corneal reflection image and the fundus reflection image as image information based on the image signal output from the light receiving section; an arithmetic processing unit that arithmetic processes the corneal shape and eye refractive power of the eye to be examined; and a single unit that displays a corneal reflection image and a fundus reflection image based on each image information stored in the frame memory unit and used for arithmetic processing. An ophthalmological measurement device consisting of a monitor section. (2) The ophthalmological measuring device according to claim 1, wherein the corneal reflection image and the fundus reflection image are simultaneously displayed on the same screen on the monitor unit. (3) The ophthalmological measuring device according to claim 1, wherein the corneal reflection image and the fundus reflection image are selectively displayed on the same screen on the monitor unit.