JPH0810225A - Ophthalmological device - Google Patents

Abstract

PURPOSE:To accurately and easily perform the alignment of a measuring system by providing a means which performs the alignment by operating manually and performing relative displacement of the measuring system for an eye to be inspected and a means which performs the alignment by driving the measuring system based on the detection result of a barometer detecting means which projects a barometer on the eye to be inspected and detects the barometer. CONSTITUTION:When automatic alignment is selected by the operation of an alignment changeover switch 66, an inspector aligns an annular reticle image 71 with the iris of a front eye part image 70 or the neighorhood of nearly center of a pupil while observing the front eye part image 70 and the reticle image 71 on a television monitor 6, and performs rough alignment by performing focusing adjustment. After that, an X driving system 63. a Y driving system 64 and a Z driving system 65 are operated by output signals from a two-dimensional detecting element 37 and a one-dimensional detecting element 53, and when a measuring unit is moved to a device main body 3, the barometer images of the two-dimensional detecting element 37 and the one-dimensional detecting element 53 are also moved, and a control circuit 62 judges whether or not respective barometer image enters the allowable range of alignment coupletion.

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 adjusting mechanism for aligning a measurement system of the ophthalmic apparatus with a predetermined positional relationship with an eye to be examined.

[0002]

2. Description of the Related Art An ophthalmologic apparatus for performing measurement or the like requires alignment of an eye to be inspected with a measurement system of the apparatus in a predetermined positional relationship during measurement, that is, adjustment of vertical and horizontal positions and adjustment of working distance. . Conventional ophthalmic device alignment is
The operator moves the device by operating a joystick or the like so that the anterior ocular segment of the eye to be examined, the alignment index, and the alignment mark have a predetermined relationship.

[0003]

The above-described alignment operation has the advantage that it is simple in itself, but when it is necessary to perform accurate alignment like a non-contact tonometer, the accuracy of the alignment operation is improved. I have a problem.

An object of the present invention is to provide an ophthalmologic apparatus capable of accurately and easily aligning a measurement system with respect to an eye to be examined in view of the above-mentioned drawbacks of the conventional apparatus.

[0005]

The present invention is characterized by having the following constitution in order to solve the above problems.

(1) In an ophthalmologic apparatus that requires alignment of a measurement system at a predetermined position with respect to an eye to be examined,
First alignment means for relatively moving and aligning the measurement system with respect to the eye to be inspected by manual operation, index detecting means for projecting an index to the eye to detect the projected index, and the index detecting means Second alignment means for driving and aligning the measurement system based on the detection result, and alignment mode switching means for switching between the alignment mode by the first alignment means and the alignment mode by the second alignment means. It is characterized by having.

(2) The ophthalmologic apparatus of (1) further determines whether or not the time measurement means for measuring the alignment time by the second alignment means and the detection result by the index detection means are within a predetermined allowable range. And a switching means for switching the alignment mode to the alignment mode by the first alignment means when the alignment by the second alignment means is not completed within a predetermined time. .

(3) The ophthalmologic apparatus of (2) is characterized by comprising notifying means for notifying that the alignment mode has been switched by the switching means.

(4) The judging means of (2) is characterized in that it has a plurality of allowable ranges of alignment and switches the plurality of allowable ranges of the alignment according to the elapsed time of the time measuring means.

[0010]

Embodiment 1 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 seen from the examiner side, and FIG. 2 is a left side view thereof. Reference numeral 1 is a base, and a base 2 is fixedly provided with a jaw base 2 for fixing the eye of the subject. Reference numeral 3 denotes an apparatus main body that slides on the horizontal plane of the base 1 in the front, rear, left, and right directions. The apparatus main body 3 moves on the base 1 by operating a 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 moved up and down with respect to the apparatus main body 3 by an operator operating a rotary knob 4a provided on the joystick 4. To do. Further, the measuring unit 5 moves about 5 mm back and forth and left and right with respect to the apparatus main body 3 in order to perform automatic alignment. A TV monitor 6 displays information to be notified to the anterior segment of the eye to be inspected and the examiner.

[Structure of Each Part] Next, each main part of the apparatus according to the present invention will be described. In addition, the non-contact tonometer deforms the cornea to a predetermined state by injecting compressed air to the cornea of the eye to be examined,
Although the intraocular pressure of the eye to be inspected is measured directly or indirectly based on the air pressure detected at that time, the description of the measurement mechanism itself is omitted because it is not relevant 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 the observation optical system, the reticle projection optical system, the front index projection optical system, the front index detection optical system, the distance target projection optical system, and the distance target detection optical system.

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

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

(Reticle projection optical system) 20 indicates a reticle projection optical system, and the reticle projection optical system 20 includes a light source 21,
It is composed of a reticle plate 22 on which an annular mark is formed, and a projection lens 23. The reticle of the reticle plate 22 illuminated by the light source 21 is imaged on the image pickup device 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 with the anterior segment image. Be done.

(Front index projection optical system) 30 is a front index projection optical system, and the front index projection optical system 30 is the illumination light source 1.
Light source 31 such as a near-infrared LED that emits light with a wavelength close to 7
And a projection lens 32. The output of the light source 31 is modulated at a predetermined frequency in order to prevent the light flux of the illumination light source 17 from becoming noise for the front index detection optical system described later.

The light from the light source 31 is collimated by the projection lens 32, reflected by the half mirror 12, passes through the inside of the nozzle 11 along the optical axis L, and is irradiated onto the cornea Ec. This light beam is specularly reflected by the cornea Ec, and the eye E
An index i1 which is a virtual image of the light source 31 is formed on the. Index i1
The luminous flux of the above forms an image of the index i1 on the image pickup element of the TV camera 16 by the observation optical system.

(Front index detection optical system) 35 is a front index detection optical system, and the front index detection optical system 35 is the field stop 3.
6, a two-dimensional position detecting element 37, and an objective lens 13, a filter 14, and a half mirror 15 which are shared with the observation optical system.
Consists of As for the diameter of the field stop 36, the unnecessary light is detected by the detection element 3
The light flux of the optotype i1 which is not incident on the TV camera 16 and is located at an almost proper position with respect to the reticle image on the TV camera 16 is detected by the detection element 3
It is set so as to enter 7. Various sensors such as CCD and PSD can be used as the two-dimensional position detecting element 37. Further, instead of the two-dimensional position detecting element, a split type photodetecting element of two or four divisions may be used.

The front index light beam specularly reflected by the cornea Ec is reflected by the half mirror 15 to detect the front index optical system 35.
Is transmitted to the field stop 36, and is received by the detection element 37. The detection element 37 detects the vertical and horizontal positions of the eye to be inspected with respect to the measurement axis (observation optical axis L) based on the two-dimensional position of the light flux of the index 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 optical axes are inclined with respect to each other, and the two optical axes intersect at a position away from the nozzle 2 by a predetermined working distance. The crossing angle of the optical axis M with respect to the optical axis L is preferably 20 degrees to 40 degrees. On the optical axis M, 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. The light emitted from the light source 41 is made into a parallel light flux by the projection lens 42, and is irradiated onto 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 to the optical axis L, and the optical axis N intersects the optical axis M on the optical axis L. A light receiving lens 51, a filter 52, and a one-dimensional detection element 53 are provided on the optical axis N. The filter 52 transmits the light of the wavelength of the light source 41 of the distance index projection optical system 40, and the illumination light source 17 and the front index projection optical system 3
It has a property of not transmitting 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 used for the one-dimensional detection element 53.
It prevents the noise from being incident on the upper part.

The cornea-reflected light flux of the light source 41 forming the index i2 passes through the filter 52 by the light receiving lens 51
It is incident on the dimension detecting element 53. When the eye to be inspected moves in the axial direction of the optical axis L (forward and backward direction), 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 eye to be inspected in the front-back direction is detected from the deviation of the index image on the one-dimensional detection element 53. A cylindrical lens having a generatrix direction in the detection direction may be arranged in front of the one-dimensional detection element 53.

The control system 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
The signals output from 3 are detection processing circuits 60 and 60, respectively.
Predetermined processing is performed at 61 and input to the control circuit 62. The control circuit 62 performs known processing on these signals,
The amount of deviation (shift) in the up / down / left / right direction and the front / rear direction with respect to the proper position of the eye E to be inspected is obtained.

Reference numeral 63 is an X drive system for moving the measuring unit 5 in the vertical direction (X direction) with respect to the observation optical axis L, and 64 is a Y drive system for moving the measurement unit 5 in the horizontal direction (Y direction) with respect to the observation optical axis L. Is moved along the optical axis L direction (Z direction) Z
It is a drive system. Each of these drive systems is composed of a motor and a motor drive circuit, and drives them based on the signals of the displacement information in each direction obtained by the control circuit 62. Reference numeral 66 is an auto-alignment changeover switch for switching between automatic and manual alignment.

Numeral 67 is a character display circuit for generating figures and characters for alignment, and numeral 68 is a synthesizing circuit for synthesizing the video signal from the TV camera 16 and the signal from the character display circuit 67.

The signal of the displacement information in the front-back direction obtained by the control circuit 62 is sent to the character display circuit 67, and the character display circuit generates a predetermined graphic signal and a position signal on the TV monitor 6 based on this signal. The signal from the character display circuit 67 is sent to the TV camera 1 by the synthesizing circuit 68.
6 is combined with the video signal from 6 and output to the TV monitor 6. 70 on the TV monitor 6 is an anterior eye image of the eye to be inspected, 71 is a reticle image, 72 is a front target image, and 73 is a distance mark created by a signal from the character display circuit. The distance mark 73 moves in real time above and below the reticle image 71 on the TV monitor 6 corresponding to the distance from the nozzle 12 to the cornea Ec, and overlaps with the reticle image 71 when the cornea Ec is at the proper working distance. . 80 is a timer circuit. 8
Reference numeral 1 is a buzzer, and 82 is a drive circuit thereof.

The operation of the apparatus having the above structure will be described with reference to the flow chart of FIG. The examiner positions the eye to be examined at a predetermined position on the chin rest 2, turns on the power switch, and turns on each light source. Illumination light source 17
The anterior ocular segment image of the eye E to be inspected illuminated by turning on the light is transmitted through the observation optical system and the reticle image by the reticle optical system together with T
The image is received by the V camera 16 and displayed on the TV monitor 6.

The alignment changeover switch 66 is operated to select auto alignment or manual alignment. The case where the auto alignment is selected will be described below.

The examiner sees the anterior ocular segment image 70 on the TV monitor 6.
And the reticle image 71 while observing the joystick 4
Further, the rotary knob 4a is operated to align the annular reticle image 71 with the iris of the anterior segment image or the vicinity of the center of the pupil, and focus adjustment is performed to perform rough alignment.

The luminous flux of the index i1 is incident on the two-dimensional detection element 37 of the detection optical system and the image pickup surface of the TV camera 16,
When the camera 16 captures the index image, the front view target image 72 is displayed on the TV monitor 6. When the luminous flux of the index i2 comes into the one-dimensional detection element 53 of the detection optical system, the distance mark 73 is displayed on the screen of the TV monitor 6. The examiner can know that the coarse alignment is completed by looking at these displays. In this case, a display indicating the completion of rough alignment may be separately provided based on the signals of the two-dimensional detection element 37 and the one-dimensional detection element 53.

When the rough alignment is completed in this way, the operation of the joystick 4 is completed and the automatic alignment is executed. In the automatic alignment, as described above, the control circuit 62 uses the output signals from the two-dimensional detection element 37 and the one-dimensional detection element 53 to control the vertical, horizontal, and front-rear directions with respect to the position when the eye E is in the proper position. After obtaining the deviation amount, the X driving system 63, the Y driving system 64, and the Z driving system 65 are operated based on the deviation information. When the measurement unit moves with respect to the apparatus main body 3 by the operation of each drive system, the two-dimensional detection element 37
The index image on the one-dimensional detection element 53 also moves, and the control circuit 62 determines whether or not each index image is within the allowable range for alignment completion.

When the automatic alignment is executed, the control circuit 62 reads the operation start time at that time from the timer circuit 80 and measures the time. When the control circuit 62 measures the operation time of the automatic alignment and determines that the detection results of the detection elements 37 and 53 are within the predetermined allowable range within the predetermined time, the control circuit 62 stops the operation of each drive system and automatically. Then, a signal for activating the measurement system is generated to perform the measurement (or after the message of alignment completion is notified to the examiner, the examiner presses a measurement start switch (not shown)).

On the other hand, if the movement of the apparatus cannot follow the movement of the eye to be inspected even if automatic alignment is executed due to the involuntary eye movement of the eye to be inspected, and the alignment is not within the predetermined allowable range within the predetermined time, the control circuit Reference numeral 62 cancels the control of each drive system, and also issues a warning sound to the buzzer 81 via the drive circuit 82 to notify the examiner that the alignment has been automatically switched to the manual operation.

When the examiner recognizes that the buzzer 81 has warned that he has switched to the manually operated alignment, the inspector executes the manually operated alignment. Alignment by manual operation of the apparatus of this embodiment is performed as follows.

When the rough alignment is completed, the anterior eye part image 70 and the reticle image 71 are displayed on the TV monitor 6.
A front target image 72 and a distance mark 73 appear. For vertical and horizontal position adjustment, the joystick 4 and the rotary knob 4a are operated to put the front view target image 72 in the circle of the reticle image 71. To adjust the position in the front-back direction, tilt the joystick 4 back and forth to move the distance mark 73 to the reticle image 71.
Match the position of.

When the control circuit 62 determines that the detection results of the detection elements 37 and 53 are within the predetermined allowable range by such manual alignment, the control circuit 62
Performs a measurement by issuing a signal to operate the measurement system. In this case, the examiner can also perform the measurement by pressing a measurement start switch (not shown).

In the above embodiment, when the automatic alignment does not fall within the predetermined allowable range even after the predetermined time has passed,
I explained the example of switching to manual operation automatically, but if the allowable range of alignment is set to rough accuracy again when it does not fall within the predetermined allowable range even after the lapse of a predetermined time,
Automatic alignment can continue.

The operation when a rough precision tolerance range is provided will be described with reference to the flowcharts of FIGS.
When the examiner completes the rough alignment as described above, the apparatus operates each drive system to perform automatic alignment with high precision. When the alignment is not completed within the predetermined time after the start of the automatic alignment, it is determined whether or not the shift of the automatic alignment with rough accuracy is selected by the alignment accuracy selection switch. If the automatic alignment with rough accuracy is not selected, a warning sound is generated in the buzzer 81 and the operation is switched to manual operation.

When there is a selection of automatic alignment with rough accuracy, the control circuit 62 determines whether or not alignment within a preset tolerance range of rough accuracy is completed, and determines that alignment is completed. Then, control of each drive system of automatic alignment is stopped, and measurement is performed with rough accuracy. Although the measurement result is displayed on the TV monitor 6, the fact that it is a measurement value with rough accuracy is also displayed.

The control circuit 62 reads the time after the transition of the rough accuracy from the timer circuit 80 and measures it. Even in the automatic alignment with rough accuracy, if the alignment is not completed within the predetermined time, the buzzer 81 emits a warning sound and switches to the manual operation as described above.

In the above example, the transition to the rough precision of the automatic alignment is selected by the alignment precision selection switch, but this switch is not always necessary and if the alignment cannot be performed with the precision precision, the automatic alignment is automatically performed. You may make a transition to a rough system.

Further, although the alignment accuracy has two steps of precise accuracy and rough accuracy, the number may be further increased if necessary.

Further, in the above embodiment, it is determined whether or not the alignment state is within the predetermined allowable range.
Although it is based on the position detection of the detection elements 37 and 53, it may be determined by the light amount level when the detection elements 37 and 53 detect the index image.

[0044]

As described above, according to the present invention,
Since the alignment can be switched between auto and manual according to the state of the eye to be inspected, the measurement becomes easy.

Further, when the auto-alignment is difficult, the operation is automatically switched to the manual operation, so that the examiner does not spend an extra measurement time, and also does not put an extra burden on the eye to be inspected. Optimal measurements can be made.

Further, according to the present invention, by preparing a predetermined permissible range of stepwise alignment, auto-alignment with rough accuracy is automatically performed on the eye to be examined which is difficult to auto-align. Therefore, the measurement can be performed by further utilizing the function of the auto alignment.

[Brief description of drawings]

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

FIG. 2 is a left side view of FIG.

FIG. 3 is a view of the alignment optical system of the apparatus of the embodiment as seen from above.

FIG. 4 is a block diagram showing a main part of a control system.

FIG. 5 is a flow chart for explaining the operation of the apparatus of the embodiment.

FIG. 6 is a flowchart for explaining the operation when a rough accuracy tolerance range is provided.

FIG. 7 is a flow chart for explaining the operation when a rough accuracy tolerance range is provided.

[Explanation of symbols]

 4 Joystick 30 Front index projection optical system 35 Front index detection optical system 40 Distance index projection optical system 50 Distance index detection optical system 62 Control circuit 63 X drive system 64 Y drive system 65 Z drive system 66 Auto alignment switch

Claims (4)

[Claims] 1. In an ophthalmologic apparatus that requires alignment of a measurement system with respect to an eye to be examined at a predetermined position, first alignment means for relatively moving and aligning the measurement system with respect to the eye to be inspected by manual operation. An index detecting unit that projects an index onto the eye to be inspected and detects the projected index; a second alignment unit that drives and aligns the measurement system based on a detection result by the index detecting unit; Alignment mode by alignment means
And an alignment mode by the second alignment means.
An ophthalmologic apparatus characterized in that it has an alignment mode switching means for switching between the modes. 2. The ophthalmologic apparatus according to claim 1, further comprising a time measuring means for measuring an alignment time by the second alignment means, and determining whether or not a detection result by the index detecting means is within a predetermined allowable range. Determining means, and when the alignment by the second alignment means is not completed within a predetermined time, the first alignment mode is set.
An ophthalmologic apparatus comprising switching means for switching to an alignment mode by the alignment means. 3. The ophthalmologic apparatus according to claim 2, further comprising an informing means for informing that the alignment mode has been switched by the switching means. 4. The ophthalmologic apparatus according to claim 2, wherein the determination means comprises a plurality of alignment allowable ranges, and the plurality of alignment allowable ranges are switched according to the elapsed time of the time measuring means.