JP3441175B2 - Ophthalmic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmologic apparatus, and more particularly, to an ophthalmologic apparatus having an alignment mechanism for positioning a measurement system or the like of an ophthalmic apparatus in a predetermined positional relationship with an eye to be examined.

[0002]

2. Description of the Related Art An ophthalmologic apparatus for performing measurements and the like aligns an eye to be inspected with a measurement system of the apparatus in a predetermined relationship during measurement.
That is, it is necessary to adjust the vertical and horizontal positions and the working distance. Conventional alignment of an ophthalmologic apparatus is performed by a measurer operating a joystick or the like to move the apparatus with respect to a base so that the subject's eye and the apparatus have a predetermined positional relationship. The alignment mechanism is composed of photographing means for photographing the anterior eye part, alignment reticle forming means superimposed on the photographed image, and alignment index forming means.

[0003]

The above-mentioned alignment mechanism has an advantage that its structure is relatively simple and its operation is simple. However, in a device such as a non-contact tonometer that requires high-precision alignment, there is a drawback that alignment requires considerable skill.

In view of the above-mentioned drawbacks of the conventional apparatus, an object of the present invention is to provide a subject without excessively burdening a measurer and a subject.
An object of the present invention is to provide an ophthalmologic apparatus capable of performing highly accurate alignment.

[0005]

SUMMARY OF THE INVENTION The present invention is characterized by having the following structure in order to solve the above-mentioned problems.

(1) In an ophthalmological apparatus having observation means for observing an image of an anterior eye of a subject's eye and aligning a measurement system to a predetermined position with respect to the subject's eye, the subject is observed while observing the subject's eye For optometry, a moving means for relatively moving the measurement system by manual operation, an index projection optical system that projects an alignment index on the cornea of the subject's eye, and an index detection optical system that detects the projected index, driving means for moving in multiple directions by the electric control with respect to the eye of the measuring system on the basis of the detection result of the index detection optical system, and more moved to the drive means
Selecting means for canceling the movement in the one-dimensional direction of the plurality of moving directions and enabling the movement in another direction by electrical control.

(2) In the ophthalmologic apparatus of (1) ,
The multiple directions are three-dimensional directions of up, down , left , right, front and back.
The ophthalmic apparatus according to claim and.

(3) The ophthalmologic apparatus of (1) further comprises:
Providing a display monitor for displaying the selection state of the selection means
It is characterized by.

[0009]

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a non-contact tonometer will be described below with reference to the drawings. [Overall Configuration] FIG. 1 is a front view of the apparatus of the embodiment as viewed from the examiner, and FIG. 2 is a left side view thereof. Reference numeral 1 denotes a base, on which a chin rest 2 for fixing a subject's eye is fixed. Reference numeral 3 denotes an apparatus main body that slides on the horizontal surface of the base 1 in the front-rear and left-right directions. The apparatus main body 3 moves on the base 1 by operating the joystick 4. Reference numeral 5 denotes a measurement unit that houses a measurement system, an optical system described later, and the like. The measurement unit 5 is electrically driven up and down with respect to the apparatus main body 3 by an examiner operating a rotary knob 4 a provided on the joystick 4. Move. Further, the measurement unit 5 moves back and forth and right and left about 5 mm with respect to the apparatus main body 3 to perform automatic alignment. Reference numeral 6 denotes a TV monitor that displays information to be notified to the anterior segment of the subject's eye and the examiner.

[Configuration of Each Unit] The main configuration of each unit of the apparatus will be described. In addition, the non-contact tonometer injects compressed air into the cornea of the subject's eye to deform the cornea to a predetermined state, and measures the intraocular pressure of the subject's eye based on the air pressure detected directly or indirectly at that time. However, the description of the measurement mechanism itself is omitted because it is not closely related to the present invention.

[0012] alignment optical system Figure 3 is a top view of the alignment optical system of the apparatus of the embodiment. The alignment optical system will be described separately for an observation optical system, a reticle projection optical system, a front target projection optical system, a front target detection optical system, a distance target target projection optical system, and a distance target target detection optical system.

(Observation optical system) 10 is an observation optical system, and L indicates its optical axis. On the optical path of the observation optical system, a nozzle 11 for blowing out a gas for deforming the cornea is arranged, and its axis and the optical axis L
Is consistent with On the optical axis L, a half mirror 12, an objective lens 13, a filter 14, a half mirror 15, a TV
A camera 16 is arranged. The filter 14 has the property of transmitting the wavelength of the light beam of the front index projection optical system described later and not transmitting the wavelength of the light beam of the distance index projection optical system, and is unnecessary for the TV camera 16 and the detection elements of the front index detection optical system. Prevents noise light from reaching.

Reference numeral 17 denotes an illumination light source that emits near-infrared light for observing the eye to be inspected. The anterior segment image of the eye E to be inspected illuminated by the lighting of the illumination light source 17 is transmitted by the objective lens 13 through the half mirror 12, the filter 14, and the half mirror 15 to T.
An image is formed on the imaging surface of the V camera 16 and is projected on the TV monitor 6.

A reticle projection optical system 20 is a reticle projection optical system.
It comprises a reticle plate 22 having an annular mark formed thereon, and a projection lens 23. The reticle of the reticle plate 22 illuminated by the light source 21 is imaged on the image sensor of the TV camera 16 by the projection lens 23 via the half mirror 15 and is projected on the TV monitor 6 so as to overlap the anterior eye image. It is.

(Front index projection optical system) 30 is a front index projection optical system, and the front index projection optical system 30 is an illumination light source 1.
Light source 31 such as a near-infrared LED that emits light having a wavelength close to 7
And the projection lens 32. The output of the light source 31 is modulated at a predetermined frequency in order to prevent the luminous flux of the illumination light source 17 from becoming a noise to a front index detection optical system described later. The light from the light source 31 is converted into a parallel light beam by the projection lens 32, and then reflected by the half mirror 12 so that the optical axis L
Then, the light passes through the inside of the nozzle 11 and the like, and is irradiated to the cornea Ec. This light beam is specularly reflected by the cornea Ec to form a target i1 which is a virtual image of the light source 31 on the eye E. The light beam of the target i1 forms an image of the target i1 on the image sensor of the TV camera 16 by the observation optical system.

(Front index detecting optical system) 35 is a front index detecting optical system, and the front index detecting optical system 35 is a field stop 3
6, the objective lens 13, the filter 14, and the half mirror 15 which are shared with the two-dimensional position detecting element 37 and the observation optical system. The diameter of the field stop 36 is such that unnecessary light is
Is not incident on the reticle image on the TV camera 16 and the luminous flux of the visual target i1 is located at an appropriate position with respect to the reticle image on the TV camera 16.
It is set to be incident on. Various sensors such as a CCD and a PSD can be used as the two-dimensional position detecting element 37. Further, instead of the two-dimensional position detecting element, a two- or four-segmented split-type light detecting element may be used.

The luminous flux of the front index, which has been specularly reflected by the cornea Ec, is transmitted to the front index detecting optical system 35 by the half mirror 15.
, Passes through the field stop 36, and is received by the detection element 37. The detecting element 37 detects the upper, lower, left and right positions of the subject's eye with respect to the measurement axis (observation optical axis L) based on the two-dimensional position of the light beam of the target i1 incident on the element surface.

(Distance index projection optical system) 40 is a distance index projection optical system, and M is its optical axis. Optical axis M is optical axis L
The two optical axes intersect at a position separated from the nozzle 2 by a predetermined working distance. The intersection angle of the optical axis M with the optical axis L is preferably 20 degrees to 40 degrees. A light source 41 such as an LED having a wavelength different from that of the light source 31 and a projection lens 42 are arranged on the optical axis M. The light emitted from the light source 41 is converted into a parallel light beam by the projection lens 42 and is irradiated on the cornea Ec along the optical axis M. The light beam specularly reflected by the cornea Ec forms an index i2 which is a virtual image of the light source 41.

(Distance index detecting optical system) 50 is a distance index detecting optical system, and N is its optical axis. Optical axis N and optical axis M
Has an axis symmetrical with respect to the optical axis L, and the optical axis N intersects the optical axis M on the optical axis L. On the optical axis N, a light receiving lens 51, a filter 52, and a one-dimensional detection element 53 are provided. The filter 52 transmits light of the wavelength of the light source 41 of the distance index projection optical system 40, and transmits the illumination light source 17 and the front index projection optical system 3.
It has the property of being impermeable to light of the wavelength of the light source 31 of 0,
The light of the index i1 or the light of the illumination light source 17 is
This prevents noise from being incident on the top.

The corneal reflected light flux of the light source 41 forming the index i 2 is received by the light receiving lens 51 through the filter 52 to be 1
The light is incident on the dimension detection element 53. When the subject's eye moves in the axial direction (front-back direction) of the optical axis L, the image of the index i2 by the light receiving lens 51 also moves in the detection direction of the one-dimensional detection element 53. The position of the subject's eye in the front-back direction is detected from the deviation of the index image on the one-dimensional detection element 53. Note that a cylindrical lens having a generatrix direction in the detection direction may be disposed in front of the one-dimensional detection element 53.

Control System FIG. 4 is a block diagram showing a main part of a control system according to the present invention. Two-dimensional position detecting element 37, one-dimensional position detecting element 5
3 are output from the detection processing circuit 60,
Predetermined processing is performed at 61 and input to the control circuit 62. The control circuit 62 performs known processing on these signals,
Up / down / left / right and back and forth deviation (shift) from the appropriate position
Get the quantity.

Reference numeral 63 denotes an X drive system for moving the measuring unit 5 in the vertical direction (X direction) with respect to the observation optical axis L; 64, a Y drive system for moving the measurement unit 5 in the left / right direction (Y direction) with respect to the observation optical axis L; Is Z to be moved along the optical axis L direction (Z direction)
Drive system. These drive systems are each composed of a motor and a motor drive circuit, and operate based on signals of deviation information in each direction obtained by the control circuit 62.

Reference numeral 66 denotes an alignment mode changeover switch for switching the operation and release of each of the drive systems 63 to 65. The alignment mode changeover switch 66 selects which operation direction in the XYZ directions is to be performed automatically or manually. Reference numeral 67 denotes a character display circuit that generates figures, characters, and the like for alignment. Reference numeral 68 denotes a combining circuit that combines a video signal from the TV camera 16 and a signal from the character display circuit 67.

The signal of the deviation information in the front-rear direction is sent to the character display circuit 67, and based on this signal, the character display circuit gives predetermined graphic signals and position signals to the TV monitor 6. The signal from the character display circuit 67 is transmitted to the synthesis circuit 6
8 is combined with the video signal from the TV camera 16 and T
Output to V monitor 6.

On the display screen of the TV monitor 6, reference numeral 70 denotes an anterior eye image of the subject's eye, 71 denotes a reticle image, 72 denotes a front target image, and 73 denotes a distance mark created by a signal from a character display circuit. is there. The distance mark 73 moves in real time above and below the reticle image 71 on the TV monitor 6 according to the distance from the nozzle 12 to the cornea Ec, and overlaps the reticle image 71 when the cornea Ec is at the proper working distance.

The operation of the apparatus configured as described above will be described. The measurer operates the alignment mode changeover switch 66 to select the alignment mode. The selection of the alignment mode is made in consideration of the state of the eye to be inspected, the measurement technique of the measurer, and the like.

First, a description will be given of a mode in which the vertical, horizontal, and front-rear directions are all automatically aligned. Illumination light source 1
The anterior eye image of the eye E to be inspected illuminated by 7 is received by the TV camera 16 together with the reticle image by the reticle optical system via the observation optical system, and is projected on the TV monitor 6. While observing the anterior eye image and the reticle image on the TV monitor 6, the examiner operates the joystick 4 and the rotary knob 4a to align the annular reticle image near the center of the iris or pupil of the anterior eye image. By adjusting the focus, the apparatus is roughly aligned with the eye to be examined.

When the light flux of the index i1 is incident on the two-dimensional detection element 37 of the detection optical system and on the imaging surface of the TV camera 16,
The front monitor target image 72 is displayed on the TV monitor 6, and the examiner can know that the rough alignment in the vertical and horizontal directions has been completed by displaying the front target image 72 on the screen. Further, when the light flux of the index i2 is incident on the one-dimensional detection element 53 and the one-dimensional detection element 53 detects the index image, T
A distance mark 73 is displayed on the screen of the V monitor 6, and the examiner can know from this display that rough alignment in the front-rear direction has been completed. When the rough alignment is completed, an indication to shift to automatic alignment is displayed based on the signals of the two-dimensional detection element 37 and the one-dimensional detection element 53.

When the rough alignment is completed, the control circuit 62 calculates the deviation based on the deviation information in the vertical and horizontal directions and the front and rear directions.
The X drive system 63, the Y drive system 64, and the Z drive system 65 are operated, respectively. When the control unit 62 determines that the measurement unit 5 is moved by the operation of each drive system and the index image has reached a position within a predetermined tolerance, the operation of each drive system is stopped to complete the alignment. When the alignment is completed, a signal for automatically operating the measurement system is automatically issued to execute the measurement (a message indicating the completion of the alignment is notified to the examiner, and the examiner presses a measurement start switch (not shown). May be).

Next, a description will be given of an operation in a case where a mode for automatically aligning only a part of directions is employed. This mode is used when the nystagmus of the eye to be inspected and the eye movements are intense and it is difficult to perform automatic alignment within a predetermined allowable range. The measurer combines the manual alignment with the automatic alignment by the operation of each drive system, and selects the most suitable alignment method by operating the auto alignment switch 66. The selected state of the alignment is displayed on the TV monitor 6.

In order to cope with the fixation tremor, the horizontal direction (X
A description will be given of a case in which the alignment of (direction) is manually performed. The coarse alignment is performed in the mode described above.
Same as C. The measurer tilts the joystick 4 left and right to move the apparatus main body 3, and aligns the front-view target image 72 appearing on the TV monitor 6 so as to be located at the center of the reticle image 71 in the left and right direction. At the same time, automatic vertical and vertical alignments are performed. The control circuit 62 drives the Y drive system 64 and the Z drive system 65 based on the detection signal,
The alignment is executed by moving the measurement unit 5 in the vertical and horizontal directions.

Two-dimensional detector 37 and one-dimensional detector 5
When the control circuit 62 determines that the alignment is within a predetermined allowable range based on the detection signal of No. 3, the operation of the Y drive system 64 and the Z drive system 65 is stopped, and a trigger signal for automatically operating the measurement system is issued. And perform the measurement. When the manual alignment is completed, the measurement start switch is pressed, and the switch signal is compared with the alignment completion signal by the two-dimensional detection element 37 and the one-dimensional detection element 53 (the manual alignment direction may be excluded). A trigger signal may be generated by an AND signal.

[0034]

As described above, according to the present invention,
Alignment can be performed according to the adaptability of the measurer or the subject's eye in the alignment direction, and measurement time can be reduced and efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a front view of an apparatus according to an embodiment viewed from an examiner.

FIG. 2 is a left side view of FIG.

FIG. 3 is a top view of an alignment optical system of the apparatus according to the embodiment.

FIG. 4 is a block diagram showing a main part of a control system according to the present invention.

[Explanation of symbols]

4 Joystick 6 TV monitor 30 Front index projection optical system 35 Frontal index detection optical system 40 Distance index projection optical system 50 Distance index detection optical system 62 control circuit 63 X direction drive system 64 Y direction drive system 65 Z direction drive system 66 Alignment mode switch

Claims (3)

(57) [Claims] 1. An ophthalmologic apparatus which has an observation means for observing an anterior eye image of a subject's eye, and needs to align a measurement system to a predetermined position with respect to the subject's eye, while observing the subject's eye. A moving means for relatively moving the measurement system by manual operation, an index projection optical system for projecting an alignment index onto the cornea of the subject's eye, an index detection optical system for detecting the projected index, driving means for moving in multiple directions by the electric control with respect to the eye of the measuring system on the basis of the detection result of the index detection optical system, moves more to the drive means
An ophthalmologic apparatus comprising: selecting means for canceling movement in one dimension among the plurality of directions and enabling movement by electrical control in another direction. 2. The ophthalmologic apparatus according to claim 1, wherein the plurality of directions are three-dimensional directions of up, down, left, right, front and back. 3. The ophthalmologic apparatus according to claim 1, further comprising a display monitor for displaying a selection state of said selection means.