JPH08280627A - Ophthalmologic apparatus - Google Patents

Abstract

PURPOSE: To enable accurate alignment by judging the propriety of the alignment based on the results of detection by a detection means to detect alignment state between eyes to be inspected and a measuring means to issue a command to start a measurement by the measuring means when the alignment state is determined to be in a specified allowable range. CONSTITUTION: When a joystick 4 is operated to move a moving base 3 horizontally, a microswitch 56 detects the horizontal switching and a detection signal is inputted into a microcomputer 70. As a result, the microcomputer 70 works to supply a power source to other measuring system circuits to shift the apparatus to readiness for measuring operation while driving a display device 11. With the entry of a measuring mode, a inspecting person conducts an adjustment of alignment observing an anterior ocular segment image of an eye to be inspected through an observation window of a measuring section 5. The microcomputer 70 judges the propriety of the adjustment of alignment by the inspecting person's moving operation and calculates the results of measurement automatically when the alignment state is in a specified allowable range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmologic apparatus for inspecting and measuring an eye to be examined.

[0002]

2. Description of the Related Art Many ophthalmic devices such as an eye refractive power measuring device and a cornea shape measuring device are of a stationary type. As a positioning mechanism for the eye to be inspected in this type of apparatus, a joystick mechanism that moves a moving table including a measuring unit with respect to a base by an operating rod called a joystick is generally used. Conventionally, this joystick mechanism has a structure shown in FIG. A spherical surface portion 102 and a lower end portion 103 are formed below the shaft 101 inserted through the operating rod 100. The spherical portion 102 is held by a ball bearing 104, and the operating rod 100 can swivel around the center of the spherical portion 102, and the lower end 103 swings the sliding plate 105 by the swiveling of the operating rod 100. The base 106 has a friction plate 10 in contact with the sliding plate 105.
7 is attached, and the sliding plate 105 is the friction plate 107.
By swinging, the horizontal movement of the movable table 108 including the measuring unit is realized. In addition, a mechanism for moving the movable table including the measuring unit with respect to the base is provided with a stopper mechanism that fixes the movable table when the apparatus is moved. The conventional stopper mechanism has been fixed by a rubber stopper by rotation with a screw.

[0003]

The joystick mechanism described above has the advantages of excellent operability and accurate alignment. However, since its structure is complicated, it has a large number of parts and is costly.
In addition, the rotary stopper mechanism using a screw has a large number of parts and has a drawback of high cost. In view of the above-mentioned drawbacks of the conventional apparatus, it is an object of the present invention to provide an ophthalmologic apparatus that includes a joystick mechanism that allows accurate alignment and has a simple structure.

[Means for solving the problem]

The present invention has the following structure in order to solve the above problems. (1) A moving table equipped with a measuring means for measuring the eye to be inspected, an operating rod provided on the moving table so as to be inclinable so as to move horizontally with respect to a fixed base, the eye to be inspected and the measuring means. Detecting means for detecting the alignment state of the, and a determining means for determining the suitability of the alignment based on the detection result by the detecting means, and when the determining means determines that the alignment state is within a predetermined allowable range, Control means for instructing the start of measurement by the measurement means.

(2) In the ophthalmologic apparatus of (1), in order to further fix the movement of the movable base with respect to the fixed base, one of the movable base and the fixed base is provided with a convex member, and the other is provided. Is provided with a fitting member that fits into the convex member.

(3) An ophthalmologic apparatus characterized in that the fitting member of (2) is a ball catch.

(4) In an ophthalmologic apparatus having a moving table equipped with a measuring means for measuring the eye to be inspected and an operating rod for horizontally moving with respect to a fixed base, the eye to be inspected and the measuring means are Detecting means for detecting an alignment state, fixing means for the movable table having a convex member provided on one of the movable table and the fixed base and a fitting member for fitting the convex member on the other side, It is characterized by including.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. [External Configuration] FIG. 1 is a schematic external view of a corneal shape measuring apparatus according to an embodiment. Reference numeral 1 denotes a base, and a head support portion 2 for fixing the head of the subject is fixed to the base 1. Three
Is a moving table that moves on the base 1 by operating the joystick 4. Reference numeral 5 denotes a measurement unit that houses an optical system for measurement and observation and an electrical system for control and calculation.
Is mounted on an up-and-down moving shaft 6 which is held by a moving table 3 so as to be able to move up and down, and a rotating knob 4a of a joystick 4 is moved up and down by a rotating operation. The measuring unit 5 of the present embodiment is detachable from the connecting member 7 fixed to the vertical shaft 6, and by removing from the connecting member 7 and connecting a battery (not shown), a handheld corneal shape measuring device is obtained. Is also ready to use. An observation window 10 for observing an eye to be inspected, a liquid crystal display 11 for displaying a measurement result, and an operation switch group 12 such as a print switch and a parameter setting switch are arranged in the measuring section 5. Reference numeral 8 is a printer that prints out the measurement data from the measuring unit 5, and 9 is an AC adapter that supplies power to the apparatus.

[Structure of Each Part] Next, the structure of each main part of the apparatus of the embodiment will be described. (Optical System) FIG. 2 is a view showing a schematic arrangement of the optical system arranged in the measuring section 1. The examiner's eye magnifies and observes the subject's eye 20 through the objective lens 21. 22 is a marking plate for aiming, 23
Is an illumination light source, and the light beam of the aiming mark that has passed through the aiming mark plate 22 when the illumination light source 23 is turned on is reflected by the beam splitter 24 toward the examiner's eye. The examiner aligns the sighting mark on the anterior segment image of the subject's eye 20 which is magnified and observed from the observation window, and performs alignment. Reference numeral 25 is a light source for fixation target, 26 is a fixation target plate having a spot opening, and 27 is a concave lens. Reference numeral 28 denotes a dichroic mirror which makes the optical axis of an index detection optical system, which will be described later, and the projection optical axis of the fixation target coaxial.
Is an imaging lens. Fixation target plate 2 illuminated by light source 25
6 is projected onto the fundus of the eye to be inspected via the dichroic mirror 28 and the beam splitter 24 by the concave lens 27 and the imaging lens 29, and the eye 20 can fixate the fixation target plate 26.

Reference numeral 30 denotes an index projection optical system, which is arranged on the same circumference centered on the observation optical axis at intervals of 45 degrees, and eight sets of the projection optical axes form a predetermined angle with respect to the observation optical axis. There is. Among the eight sets of index projection optical systems, four sets of cornea shape measuring optical systems 30a to 30d arranged at 90-degree intervals.
(30c and 30d are not shown), which comprises a light source 31 such as an LED for emitting light in the near infrared region, a spot diaphragm 32, and a collimator lens 33 for keeping the spot diaphragm 32 at infinity. Optical system 30a for measuring corneal shape
30d is also used as an optical system for detecting the working distance, and the optical system for detecting the working distance is an optical system for projecting an infinite light beam, and an optical system for projecting a finite light beam including a light source 31 and a spot diaphragm 32. 30e to h (not shown). The index detection optical system includes a beam splitter 24, an imaging lens 29, a telecentric diaphragm 3
4 and a two-dimensional position detecting element 35. The telecentric diaphragm 34 is arranged at the focal position of the imaging lens 29. The two-dimensional position detecting element 35 is arranged at a position conjugate with the vicinity of the iris where the cornea reflection image is formed with respect to the imaging lens 29, and detects the cornea reflection image by the index projection optical system 30. Reference numerals 36 are LEDs arranged on the same circumference centered on the observation optical axis at intervals of 30 degrees. The entire corneal reflection image of each LED 36 functions as a earring.
The LED 36 also serves as illumination of the anterior segment.

(Joystick Mechanism) FIG. 3 is a sectional view for explaining a moving mechanism by a joystick, and FIG. 4 is a sectional view taken along line AA. The moving mechanism will be described separately for the vertical moving mechanism and the horizontal moving mechanism. The vertical movement mechanism
The joystick support rod 41 erected on the plate 40 of the movable table 3, the bearing 42 rotatable with respect to the joystick support rod 41, the rotary knob 4a fixed to the upper portion of the bearing 42, and the bearing 42 Gear 43 fixed to the lower part
And a measuring unit side support rod 44 erected on the plate 40,
A cylinder 46 to which a feed nut is attached so as to be rotatable with respect to the support rod 44, a vertical movement shaft 7 having a feed screw that meshes with a screw of the feed nut of the cylinder 46, and a gear 48 fixed to a lower portion of the cylinder 46. And a belt 49 hung between the gear 48 and the gear 43. When the rotary knob 4a is rotated, the rotation is transmitted to the cylinder 46 via the gear 43, the belt 49, and the gear 48, and the cylinder 46 rotates to vertically move the vertical movement shaft 6 to move the measuring unit 5 up and down. .

The horizontal moving mechanism has two bases 50 on the base 1.
A lower substrate 52 that is movably held in the front-rear direction (with respect to the eye to be inspected) via two slide rails 51, and a lower substrate 5
2, an upper substrate 54 movably held in the left-right direction via two slide rails 53, an upper substrate 54, and a moving base 3
And a support base 55 connecting the plate 40 of FIG. With this configuration, the moving table 3 can be moved independently of the front, rear, left, and right with respect to the base 1, and the examiner holds the joystick 4 to move the measuring section 5 on the moving table 3 horizontally. realizable.

(Inspection Eye Left / Right Detection Mechanism) In FIGS. 3 and 4, reference numeral 56 is a microswitch attached to the plate 40 by an attachment plate 57, and 58 is a guide plate attached to the lower substrate 52. As the plate 40 fixed to the moving table 3 moves in the left-right direction, the micro switch 56 also moves in the left-right direction (up-down direction in FIG. 4) with respect to the lower substrate 52. As shown in FIG. 4, the micro switch 56 is moved to the left (see FIG.
Moving downward (upward and downward), the contactor moves the guide plate 58.
It comes into contact with and is energized. Since the center of the left and right of the subject fixed to the head support portion 2 substantially corresponds to the center of the left and right of the base 1, the micro switch 56 that moves left and right is turned on.
The left / right of the eye to be inspected is detected by the / OFF signal.

(Stopper Mechanism) In FIGS. 3 and 4,
Reference numeral 60 is a ball catch fixed to the base 50 of the base 1 via a mounting plate 61, and reference numeral 62 is a convex member fixed to the upper substrate 54. The ball catch 60 is formed by the recess member 6
Two hard spheres 60b held at 0a and the hard spheres 60b
A spring 60c for urging each spring inward, and a spring 60c
The adjusting screw 60d for adjusting the urging force of c. This stopper mechanism is used when it is desired to fix the movement of the moving table 3 with respect to the base 1 when carrying the apparatus to another place and moving it. For fixing, the joystick 4 is operated to position the movable table 3 substantially at the center of the left and right of the base 1, and then the front side (inspector side) is pulled so that the convex member 62 of the stopper mechanism is attached to the ball catch 60. Make it fit. To release the fixation of the movable table 3, hold the joystick 4 and push it to the back side (the subject side). The convex member 62 is disengaged from the ball catch 60, and the movable table 3 can be moved horizontally. Since the convex member 62 and the ball catch 60 of the stopper mechanism can use commercially available products, the manufacturing cost of the device can be reduced.

(Electrical System) FIG. 5 is a block diagram of an essential part of the electrical system of the apparatus. Reference numeral 70 is a microcomputer incorporated in the measuring unit 1. The micro computer 70 controls the entire apparatus, and also performs a predetermined calculation process based on a detection signal from the two-dimensional position detecting element 35 which is subjected to a predetermined process by the detection processing circuit 71 and input, to perform alignment. The suitability is determined and the corneal shape is calculated. The microcomputer 70 has a nonvolatile memory 72 for storing constants peculiar to the device, a display circuit 73 of the display unit 11, a drive circuit 74a of the buzzer 74, and a drive circuit 7 for driving each light source.
5 to 78, power contacts 79a and 79b for receiving power from the AC adapter 9, and signal communication contacts 81a and 81b via the input / output circuit 80. 82a, 8
Reference numeral 2b is a contact provided on the connecting member 7 so as to correspond to the power contacts 79a and 79b, and is connected to the AC adapter 9. 83a and 83b are signal communication contacts 81a and 81
The contact point is provided on the connecting member 7 so as to correspond to b, is connected to the input / output circuit 84, and is connected to the micro switch 5
6. Signal communication with the printer 8 is performed.

The operation of the apparatus having the above configuration will be described. When a power switch (not shown) arranged on the AC adapter 9 is turned on, power is supplied to the microcomputer 70 via the power contacts 82 and 79.
At this stage, the microcomputer 70 does not supply power to other electric circuits and stops the measurement operation. When the joystick 4 is operated to move the movable table 3 in the left-right direction, the movement causes the microswitch 56 to detect the switching between the left and right, and the detection signal is input to the microcomputer 70. Upon receiving a signal input from the micro switch 56, the micro computer 70 drives the display 11 via the display circuit and supplies power to other measurement system circuits to measure the device in an operable state (hereinafter, (Measurement mode). Once in the measurement mode,
The examiner performs alignment adjustment while looking through the observation window 10 of the measurement unit 5 and observing the anterior segment image of the subject's eye. For alignment adjustment, the measuring unit 5 is moved forward and backward together with the movable table 3 by operating the joystick 4, and the measuring unit 1 is rotated by operating the rotary knob 4a so that the aiming mark has a predetermined relationship with the anterior segment image. Up and down.

The microcomputer 70 determines whether or not the alignment adjustment by the moving operation of the examiner is appropriate. Whether or not the alignment in the vertical and horizontal directions is appropriate is determined by the index projection optical system (30a-
302h), the judgment is made by comparing the deviation between the center of a pair of opposed corneal reflection images and the measurement optical axis. The suitability in the front-back direction (hereinafter referred to as working distance) is determined by comparing the image heights of the corneal reflection images formed by the index projection optical systems 30a to 30d at infinity and the index projection optical systems 30e to 30h at infinity. Made by. This is because when a corneal reflection image is formed by an infinite light source and a finite light source, the image height of the corneal reflection image by the infinite light source does not change even if the working distance changes, but the corneal reflection image by the finite light source. This utilizes the characteristic that the image height of the image changes. The details of this are described in Japanese Patent Application No. 4-224896 (the title of the invention: "alignment detecting device") by the present applicant, so please refer to it. 1 for each light source with the same projection optical axis
The suitability of the working distance can be determined if individual index images are obtained, but in this embodiment, an elliptical shape connecting the corneal reflection images of the index projection optical system (30a to 30d) at infinity by the micro computer, Finite distance index projection optical system (30e-30
Each of the elliptical shapes connecting the corneal reflection images of h) is obtained, the position of each ellipse in the predetermined meridian direction (which may be at a certain angle or may be determined as the astigmatic axis direction) is extracted, and the heights thereof are compared.

When both image heights match within a predetermined allowable range, and the center of the corneal reflection image and the measuring optical axis match within a predetermined allowable range, the microcomputer 70 causes the image height to match. The corneal shape is calculated from the position of the corneal reflection image of the index projection optical system (30a to 30d). To calculate the corneal shape, as described in Japanese Patent Application No. 59-207539 (Invention title "Corneal shape measuring device" Japanese Patent Publication No. 1-19896), if at least three index images are detected, the corneal shape is calculated. Can be calculated.
The measurement result is displayed on the display unit 11. In this way, the device determines whether the alignment adjustment is appropriate and automatically calculates the measurement result if the alignment state is within the predetermined allowable range. Therefore, the movement of the measuring unit 5 with respect to the base 1 is performed by the coarse movement by the joystick mechanism described above. However, it is possible to measure in an accurate alignment state.

The measurement for calculating the corneal shape of one eye is continuously executed a predetermined number of times in advance (the setting of the number of measurements for one eye can be changed and set by a parameter setting switch),
The number of measurements and the obtained measurement data are stored in the non-volatile memory 72. The microcomputer 70 obtains the average value and the standard deviation of the stored measurement data, and if the standard deviation is within a predetermined value (for example, within ± 0.05 mm), it is determined that the measurement is completed normally. If the standard deviation deviates from the predetermined value, it is determined that there is abnormal data due to the influence of fixation disparity or the like, and the measurement is continued. Then, except for the data that deviates the most, the same standard deviation is determined,
Additional measurement is performed until it falls within the specified value. If the measurement is interrupted (the corneal reflection image from the subject's eye cannot be obtained) before the predetermined number of measurement data is obtained, the micro computer 70 measures the measurement mode after a predetermined time elapses. To cancel. When the standard deviation is within a predetermined value and a predetermined number of measurement data are obtained, the microcomputer 70 cuts off the power supply to each electric element and releases the measurement mode. When the measurement mode is released, the aiming mark and the Meiring image observed through the observation window 10 disappear, so that the examiner can know that the measurement of one eye is completed.

The moving table 3 is used to measure the other eye.
When the measuring unit 5 is moved in the horizontal direction together with it, the micro switch 56 detects switching between left and right, and the micro computer
Signal to the computer 70. The micro computer 70 again supplies the power which was cut off, and returns the apparatus to the measurement mode. By the inspector adjusting the alignment,
Microcomputer 70 performs similar processing to obtain measurement data for the other eye. When the measurement data of both eyes is obtained within the predetermined standard deviation and the predetermined number of times or more, the microcomputer 70 drives the printer 8 to measure the measurement data of both eyes.
Print out the data. When another data processing device or the like is connected, the measurement data is transferred and output. Largely deviated data is removed at the time of data output as described above, but if necessary, the output data may be output with an identification mark.

After a lapse of a predetermined time (for example, 3 minutes) after outputting the data, the microcomputer 70 stops the power supply to the peripheral circuits, erases the display, and turns off the display. afterwards,
When the moving table 3 is moved, such as when the subject is replaced, a signal from the micro switch 56 is obtained, and the measurement mode is entered again. When the measurement of the new eye is completed, the previous data stored in the microcomputer 70 is rewritten. In this way, after the power switch of the AC adapter 9 is first operated, a series of measurements from the start of measurement to the data output can be performed without operating the switch. The print output and the power-off of the measuring unit main body 5 may be arbitrarily performed by the switches arranged in the switch group 12.

[0022]

As described above, according to the present invention,
When the alignment state is within the predetermined allowable range, the measurement calculation process is automatically operated, so that the joystick mechanism can be simplified and the cost of the device can be significantly reduced. Further, since the stopper mechanism has a simple structure, the cost of the device can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic external view of a corneal shape measuring apparatus as an example.

FIG. 2 is a diagram showing a schematic arrangement of an optical system arranged in a measuring section.

FIG. 3 is a cross-sectional view for explaining a moving mechanism using a joystick.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a block diagram of an essential part of an electric system of the apparatus.

FIG. 6 is a diagram illustrating a conventional joystick mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 3 Moving stand 4 Joystick 5 Measuring part 30 Index projection optical system 35 Two-dimensional position detection element 70 Microcomputer

Claims (4)

[Claims] 1. A movable table equipped with a measuring means for measuring an eye to be inspected, an operating rod which is provided on the movable table so as to be inclinable so as to move horizontally with respect to a fixed base, and an eye to be inspected. When a detection unit that detects an alignment state with the measurement unit, a determination unit that determines the suitability of the alignment based on a detection result by the detection unit, and the determination unit determines that the alignment state is within a predetermined allowable range And a control means for instructing the measurement start by the measurement means. 2. The ophthalmologic apparatus according to claim 1, further comprising a convex member provided on one of the movable base and the fixed base in order to fix the movement of the movable base with respect to the fixed base, and on the other side. An ophthalmologic apparatus comprising a fitting member fitted to the convex member. 3. The ophthalmologic apparatus according to claim 2, wherein the fitting member is a ball catch. 4. An alignment between an eye to be inspected and a measuring means in an ophthalmologic apparatus having a moving table equipped with a measuring means for measuring the eye to be inspected and an operating rod for horizontally moving with respect to a fixed base. A detecting means for detecting a state; a convex member provided on one of the movable table and the fixed base; and a fixing means for the movable table having a fitting member fitted to the convex member on the other side. An ophthalmologic apparatus comprising: