JPS63139529A - Alignment apparatus of ophthalmic machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 11Δ and attack (Industrial application field) The present invention is a refractometer-1 fundus camera.

The present invention relates to alignment devices for ophthalmic instruments such as off-salmometers and non-contact tonometers. More specifically, a pair of index lights are projected onto the subject's eye to form two index images, and an alignment index based on the two index images is displayed on the TV together with the anterior segment image.
This invention relates to an improvement in an alignment device for an ophthalmological instrument, which adjusts the alignment of the working distance of the machine body with respect to the eye to be examined, the vertical and horizontal position of the machine body with respect to the eye to be examined, etc., based on the alignment index while observing R on a monitor.

(Prior Art) The present applicant has previously proposed an alignment device for a non-contact tonometer as an alignment device for ophthalmic instruments (see Japanese Patent Application No. 60-59994).
The non-contact tonometer alignment device disclosed in No. 994 includes a first index projection system that projects a first index light onto the eye to be examined to form a first index image, and a second index light that projects the second index light onto the eye to be examined. and a second target projection system for forming a second target image.

In this method, the first index image and the second index image are observed together with the anterior segment image using a TV camera, and the first index image, the second index image, and the second index image are observed together with the anterior segment image using a TV camera. The working distance is determined based on whether the index images match or do not match, and the first index image and the second index image are optically aligned in advance with respect to the air pulse discharge nozzle axis as the alignment axis. The vertical and horizontal alignment of the eye to be examined is adjusted by matching the alignment scale arranged coaxially. Note that in this device, a photodiode is provided at a position optically conjugate to the alignment scale in order to photoelectrically detect the completion of alignment and automatically emit an air pulse.

(Problems to be Solved by the Invention) By the way, in the non-contact tonometer alignment device described above, the alignment scale accurately forms an image at the position of the imaging surface of the TV camera when alignment is accurately performed. In addition, the photodiode or the averte that guides the index light to the photodiode in a limited manner must be precisely aligned with respect to the alignment scale, and this manufacturing There is a problem in that assembly work requires considerable skill and considerable ingenuity.

In addition, a photodiode is used to photoelectrically detect the completion of alignment, and the examiner's alignment Ijl is
A camera is used, and the image pickup tube of a TV camera has a kind of photoelectric storage effect, and its sensitivity is much higher than that of a photodiode.

It is difficult to strike a balance between the two, and increasing the sensitivity of the photodiode light receiving circuit poses problems in terms of S/N and response speed.

In addition, because the index image is a point image, it is impossible to judge whether the working distance of the machine body is too far forward or too far behind the standard working distance, making alignment operations inconvenient, and in the worst case, There is also the problem that the main body hits the subject's eye, which is not desirable from a safety standpoint.

An alignment device for an ophthalmic machine according to the present invention.

This was done in view of the various problems mentioned above, and the first
The object of the present invention is to provide an ophthalmological instrument alignment device that can perform alignment adjustment without providing a scale projection system for projecting an alignment scale, and eliminates the need for position adjustment process between the scale projection system and a TV imaging surface. There is a particular thing.

A second object of the present invention is to provide an alignment device for an ophthalmic instrument that allows an examiner to easily determine whether the ophthalmic machine body is too far forward or too far behind the eye to be examined when adjusting the working distance. Our goal is to provide the following.

Yet another object of the present invention is to provide an ophthalmic instrument alignment device that overcomes the drawbacks associated with photodiodes.

(Means for solving the problem) The ophthalmological instrument according to the present invention is characterized by the first index projection system and the second index projection system.
a first state in which both the index projection system and the index projection system are in the index non-projection state; a second state in which only the first index projection system is in the index projection state; and a second state in which only the second index projection system is in the index projection state. control means for controlling the first index projection system and the second index projection system so as to sequentially repeat the three states;

Two-dimensional position information of the first index image is obtained by subtracting the image information obtained by the imaging means in the first state from the image information obtained by the imaging means in the second state, and , subtracting the image information obtained by the imaging means in the first state from the image information obtained by the imaging means in the third state to obtain two-dimensional position information of the second index image. , a graphic circuit that creates graphic information for specifying an alignment operation direction from the two-dimensional position information of the first index image and the two-dimensional position information of the second index image; The apparatus is provided with display means for synthesizing and displaying image information and its graphic information.

(Example) FIG. 2 is a diagram showing an alignment optical system of an alignment device for an ophthalmic machine according to the present invention, in which 1 is a first optical system;
2 is a second optical system. The first optical system 1 and the second optical system 2 are connected to an alignment axis 1ion of the air pulse emission nozzle 3.
They are arranged at symmetrical positions with the axis of symmetry as the axis of symmetry. An objective lens 4 is provided on the alignment axis On.

This objective lens 4 has a function of forming an anterior segment image K (see FIG. 3) on a light receiving surface 5a of a CCD 5 as an imaging means.

The first optical system 1 has a first index projection system 6 and a first index observation system 7, and the second optical system 2 has a second index projection system 8 and a second index I.
It has a lK detection system 9. The first index projection system 6 has an LEDIO as a light source, and the light of the LEDIO passes through an aperture 11 as an index, is reflected by a half mirror 12,
It is guided to the projection lens 13. The projection lens 13 has a focal point at the position of the aperture 12, and the light from the light source 10 is converted into a parallel light beam by the projection lens 13, and is projected onto the cornea C of the eye E as an index light, and the specular reflection of the cornea C As a result, a virtual image I is formed on the cornea C as an index image. The reflected light forming this virtual image is transmitted to the second optical system 2.
After passing through the projection lens 14 of is formed as a target image 11' (see FIG. 3).

Similarly, the second target projection system 8 of the second optical system 2 has an LED 19 as a light source, and the light from the LED 19 passes through an aperture 20 as a target, is reflected by a half mirror 15, and is directed to the projection lens 14. It is something that is guided. The projection lens 14 has a focal point at the aperture 20.

The light from the LED 19 is made into a parallel light beam by the projection lens 14, and is projected onto the cornea C of the eye E to be examined as an index light. Then, a virtual image 12 is formed as an index image on the cornea C by corneal specular reflection of the index light. The reflected light forming the virtual image 12 passes through the projection lens 13 of the first optical system 1 and the half mirror 12, and then passes through the imaging lens 23 between the mirror 21 and the mirror 22 of the first index observation system 7. Guided by
The image forming lens 23 forms an image on the light receiving surface 5a of the CCD 5 as an index image i,' (see FIG. 3).

Then, the vertex of the cornea C and each optical axis 01.0 of the first optical system 1 and the second optical system 2. When the intersection point P of the alignment axis On of the air pulse emission nozzle 3 coincides with the corneal vertex,
The virtual image ii, i is located on ○1.02 and on the focal plane of the cornea C, and on the light-receiving surface 5a of the CCD 5, the index images i', i2/ coincide, and at this time A normal reference working distance WD can be obtained.

The outline of the configuration described above is based on Japanese Patent Application Laid-Open No. 61-1289.
Publication No. 37 or the patent application filed earlier by the applicant in 1986-
No. 59994.

FIG. 1 shows a block circuit of a 7-line alignment device for an ophthalmological instrument according to the present invention, in which the CCD 5 is connected to a TV camera 30.
The CCD 5 is driven by a CCD drive circuit 31 which also serves as a signal processing circuit.
The accumulated charge accumulated in the CD 5 is taken out as an image signal from a CCD drive circuit 31 which also serves as a signal processing circuit. The image signal is transmitted to a timing control circuit 32 and a subtraction control circuit 33 which also serves as an A/D conversion circuit.
is entered.

The timing control circuit 32 has a function of alternately driving the LED drive circuit 34 and the LED drive circuit 35 each time the -vertical synchronization signal is input.
4.35 are not driven, no index is projected onto the eye E to be examined, and both the first index projection system 6 and the second index projection system 8 are in the first state of the index non-projection state.

When the LED drive circuit 34 is driven and the LED drive circuit 35 is not driven, only the first index projection system 6 is in the second index projection state, the LED drive circuit 35 is driven, and the LED
When the drive circuit 34 is not driven, only the second index projection system 8 is in the third index projection state, and the timing control circuit 32 sequentially repeats this by switching the first index projection system 6 and the second index projection system 8 to the third index projection state. It functions as a control means to control.

The subtraction control circuit 33, which also serves as an A/D conversion circuit, constitutes a part of a graphic circuit 36, and this graphic circuit 36 has a subtraction control circuit 33 that functions as a first frame memory 37, a second frame memory 38, and a third frame memory 39. circuit 4
0, an arithmetic processing circuit 41, and a graphic memory 42. The first frame memory 37 has an A/D
Under the control of the subtraction control circuit 33 which also serves as a conversion circuit, both the first target projection system 6 and the second target projection system 8 display only the anterior segment image as the image information in the first state in which the target is not projected. It is stored as shown in FIG. 3(a). The image information stored in the first frame memory 37 is input to a subtraction circuit 40.

Under the control of the subtraction control circuit 33 which also serves as an A/D conversion circuit in the second state, the subtraction circuit 40 generates an anterior eye image containing the index image i□' together with the image information stored in the first frame memory 37. 1 is input as an image signal to the anterior segment image (see FIG. 3(b)), the subtraction circuit 40 subtracts the anterior segment image K from 1 to the anterior segment image, and stores the subtraction result in the second frame memory. 38. The second frame memory 38 stores the subtraction result as two-dimensional position information of the first index image i□' (see FIG. 3(c)).

Next, in the subtraction circuit 40, in the third state, the A/D
Under the control of the subtraction control circuit 33 which also serves as a conversion circuit, the anterior segment image including the second index image 12' together with the image information stored in the first frame memory 37 is input as an image signal (the third (see figure (d)), subtraction circuit 4
0 subtracts the anterior eye image K from the anterior eye image and outputs the subtraction result to the third frame memory 39.

The third frame memory 39 stores the subtraction result in the second index image i.
2' as two-dimensional position information (Fig. 3(e)
), here.

Two-dimensional position information of first index image ii', second index image 12
' Only the two-dimensional position information is extracted from the subtraction circuit 40 because the movement of the eye E to be examined is slow with respect to the repetition period from the first state to the third state, and the anterior segment image does not include the first
This is because the period from the state to the third state can be regarded as open.

The two-dimensional position information stored in the second frame memory 38 and 40 is input to the arithmetic processing circuit 41. The arithmetic processing circuit 41 calculates the alignment position of the instrument body with respect to the eye E based on the two-dimensional position information of the first index image i□′ and the two-dimensional position information of the second index images i,′, As a result, a signal for selecting one of three alignment indicators SS (see FIG. 4), which will be described later, is output to the graphic memory 42 as graphic information. here.

This graphic memory 42 stores graphic information regarding the three alignment fingers 411SS, large, medium, and small, and also stores in advance graphic information regarding the alignment scale As as shown in FIG. The graphic information is input to a TV signal converting circuit 43 together with information regarding the anterior segment image K, and the image is synthesized by the TV signal converting circuit 43 and input to a display 44 serving as display means. This display 44 displays the anterior segment image as well as its graphic information.

Here, the storage address of the information regarding the alignment scale AS can be changed by an input device 45 and a preset circuit 46, and by operating this input device 45, the position of the alignment scale AS displayed on the display 44 can be changed. can be changed vertically and horizontally (see Fig. 4), and the alignment scale AS can be set at an appropriate position.

Next, an example of the calculation of the calculation processing circuit 41 of the ophthalmological instrument alignment device according to the present invention will be explained.

As shown in FIG. 6, assuming that there is no deviation between the first index image 11 and the second index image 12' in the Y direction, the first index image 11'
The two-dimensional position of the alignment scale is (X,, Y,), and the two-dimensional position of the second index image it' is (xz, yi).The center position of the alignment scale in the X and Y directions is (x o -Y
a), the position of the corner point of the rectangle is (X s e Y
s ), (Xpe Yg), (Xs+, Yp), (X
p vYs), the arithmetic processing circuit 41 first calculates X1=Xi, Xi>Xz, as shown in FIG.
Determine whether Xs < Xt (Step 5
t) -X1=Xt, the first index image 11', the second
Since the index images 51 match, the working distance WD
is appropriate, outputs a signal to the graphic memory 42 to perform the process of selecting the intermediate alignment index SS (step St), and outputs a signal to the graphic memory 42 to perform the process of selecting the small alignment index SS when Xl>Xi. Step S3).

When X L < x t, the large alignment index SS
A signal for performing the process of selecting (step S4) is output to the graphic memory 42.

Here, the size of the middle 7th alignment index SS is.

The large alignment index SS is the same size as the alignment scale As, and the large alignment index SS is the same as the alignment scale As.
The small alignment index SS is set larger than s.
A medium alignment index SS, which is set smaller than the alignment scale AS, means that the working distance of the instrument body with respect to the eye E to be examined is appropriate, and a small alignment index SS means that the instrument body is too far away from the eye E to be examined. This means that the large alignment index SS means that the instrument body is too close to the eye E to be examined.

Next, the arithmetic processing circuit 41 performs processing to determine the center position Xc in the X direction of the first index image iU' and the second index image iS (
In step S5), the direction of movement and the amount of movement of the instrument body are calculated from the center position (X c, Y , ), and the calculation results are output to the graphic memory 42 .

The graphic memory 42 outputs the calculation results to the display 44, and the display 44 displays alignment fingers @SS as shown in FIGS. 8 to 14 on the anterior segment image based on the calculation results. Displayed together with alignment scale As. Note that illustration of the anterior segment image is omitted here.

Figure 8 shows the working distance WD of the instrument body with respect to the eye E to be examined.
, shows a state in which the 7 alignment index SS is appropriate in the sense that the vertical and horizontal positions are appropriate, and FIG. Therefore, it is necessary to move the instrument body diagonally downward and bring the instrument body closer to the eye E to be examined. Figure 10 shows that the vertical and horizontal positions of the instrument body with respect to the eye E to be examined are correct, but the main body of the instrument is This shows that the instrument is too close to the eye E, and it is necessary to move the instrument body away from the eye E. In Figure 11, the instrument body is diagonally below the eye E, and the instrument is not placed in the eye E. This shows that the main body is too close, and it is necessary to move the main body diagonally upward and move it away.
Although the vertical and horizontal positions of the instrument body are appropriate, it does not return to the subject's eye E. Figure 13 shows that although the working distance WD for the subject's eye E is appropriate, the instrument body is directly above the subject's eye E. It is misaligned and requires an operation to move it directly below.

The arithmetic processing circuit 41 repeats steps S to S6 according to the operation of the instrument body, and each time, Xs≦xe≦X.
p, Yg≦Y1≦YP (Step S), when it is determined that rYEsJ, it is assumed that the alignment index SS and the alignment scale AS match, and the drive circuit 48 as the fluid discharge means 47 The drive circuit 48 excites the solenoid 49, and the piston 50 is moved by the solenoid 49.
Fluid discharge from the fluid discharge nozzle 3 is started.

In the embodiments described above, the CCD 5 is used as an imaging means because the pixel position accuracy of the CCD 5 is better than that of an image pickup tube. Also, in the example.

Based on the processing result of the arithmetic processing circuit 41, the fluid discharge means 4
7, there is no need for a photodiode to automatically discharge the fluid.

l1jS11 As explained above, the alignment device for an ophthalmic instrument according to the present invention has a first state in which both the first index projection system and the second index projection system are in the index non-projection state, and the first index in the first state. the first index projection system and the second index projection system so as to sequentially repeat a second state in which only the projection system is in the index projection state and a third state in which only the second index projection system is in the index projection state. and control means for controlling.

Two-dimensional position information of the first index image is obtained by subtracting the image information obtained by the imaging means in the first state from the image information obtained by the imaging means in the second state, and , subtracting the image information obtained by the imaging means in the first state from the image information obtained by the imaging means in the third state to obtain two-dimensional position information of the second index image. , a graphic circuit that creates graphic information for specifying an alignment operation direction from the two-dimensional position information of the first index image and the two-dimensional position information of the second index image; The feature is that it is equipped with a display means that synthesizes and displays image information and its graphic information, so alignment adjustment can be performed without installing a scale projection system that projects the alignment scale, and this scale projection This has the effect of eliminating the need for a position adjustment process between the system and the TV imaging surface.

Furthermore, when adjusting the working distance, the examiner can easily determine whether the ophthalmological instrument body is too far in front or too far behind the eye to be examined.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the main part configuration of an alignment device for an ophthalmic instrument according to the present invention, FIG. 2 is a schematic diagram of an alignment optical system used in the alignment device for an ophthalmic instrument according to the present invention, and FIG. 4 is a diagram showing an example of the alignment index according to the present invention. FIG. 5 is a diagram showing an example of the alignment scale according to the present invention. FIG. is an explanatory diagram for explaining an example of the operation of the arithmetic processing circuit according to the present invention, FIG. 7 is a flowchart for explaining an example of the operation of the arithmetic processing circuit, and FIGS. FIG. 3 is an explanatory diagram for explaining the relationship between an alignment scale and an alignment index displayed on such a display. 5... CCD 6... First index projection system 8... Second index projection system 10.19... LED 32... Timing control circuit 36... Graphic circuit 44... Display K. ...Anterior segment image i, /...First index image i %...Second index image Fig. 3 Fig. 8 Fig. 10 Fig. 12 Fig. 9 Fig. 13

Claims (2)

[Claims] (1) A first index projection system that projects a first index light onto the subject's eye to form a first index image; and a second index that projects a second index light onto the subject's eye to form a second index image. An alignment device for an ophthalmic instrument, comprising a projection system, and an imaging means that receives the first index image and the second index image and receives an anterior segment image, the first index projection system and the second index. a first state in which both the projection system and the first index projection system are in an index non-projection state, and a second state in which only the first index projection system is in an index projection state;
the first index projection system and the second index projection system so as to sequentially repeat a third state in which only the second index projection system is in the index projection state;
a control means for controlling the index projection system; and a control means for controlling the index projection system; While determining the two-dimensional position information of the index image, the image information obtained by the imaging means in the first state is subtracted from the image information obtained by the imaging means in the third state. Two-dimensional position information of the two index images is obtained, and graphic information for specifying an alignment operation direction is created from the two-dimensional position information of the first index image and the two-dimensional position information of the second index image. An alignment device for an ophthalmological instrument, comprising: a graphic circuit; and a display unit that synthesizes and displays image information in the first state and the graphic information. (2) The alignment device for an ophthalmic machine according to claim 1, wherein the imaging means is a CCD imaging device.