JPH0298333A - Eye-ball motion image pick-up device - Google Patents

Abstract

PURPOSE:To enable correct diagnosis without image correction by adding an X-axis value and a Y-axis value corresponding to the respective picture elements of a pupil image to calculate the center of gravity value to be output as X-Y co-ordinate signal. CONSTITUTION:An eye-ball pupil image forming device 1 is adapted to apply uniform light totally to an eye-ball in the substantially same direction as the optical axis of a matrix camera 2 to form a pupil image, and the matrix camera 2 passes the optical signal through a lens 17 of the matrix camera 2 to be formed as a pupil image on a solid-state image pick-up element. A matrix controller 3 creates a clock signal for controlling a solid-state image pick-up element of the matrix camera 2, an X-Y scanning signal and an output data signal. An X-Y axis value adder 4 comprises an adder for obtaining the center of gravity of a pupil image of an eye-ball, a counter and a register. A data processing unit 5 calculates X-Y coordinate value of the center of gravity of a pupil image by a computer, and a digital value is output as an analog signal. The obtained analog signal is used as data for diagnosing a patient's disease.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is aimed at detecting disorders in the visual organs, vestibule, brainstem, cerebrum, or cerebellum, etc.
The present invention relates to an eye movement imaging device capable of inspecting or analyzing the above-mentioned disorders by capturing the movement of the eyeball as the movement of the pupillary reflex image when the eye is gazed at a slowly or rapidly moving target of 0 cm.

Damage to the visual organs, vestibule, brainstem, cerebrum, or cerebellum causes dizziness and imbalance. In recent years, inspection devices for detecting these defects have been developed.

That is, an electronystagmus recording device, an analysis device, or an image recording device that has a subject gaze at a target, striped pattern, etc. on a screen 50 cm to 100 cm in front of the eyes, extracts and records or analyzes the movement of the eyeballs as a bioelectrical signal. Eye movement imaging devices that perform processing, analysis, and diagnosis have begun to be developed.

[Prior art]

Conventionally, this type of eye movement imaging device irradiates the eyeball with illumination light from an oblique direction, photographs the eyeball with a CCD imaging camera, observes the patient's eyeball movement on a monitor, or performs image processing based on the photographed image. and was conducting analysis processing for diagnosis.

In addition, the eye movement imaging device developed by the applicant optically coaxially aligns the optical axis of infrared radiation to the eyeball, the optical axis of the matrix camera lens, and the visual axis of the eyeball when the eyeball looks directly ahead. By using an infrared reflecting mirror and a dichroic mirror that reflects infrared rays and transmits visible light, it was possible to accurately image the movement of the eye and pupil without performing correction calculations.

Further, the eye movement imaging device calculates the XY coordinates by scanning the spot image in the horizontal and vertical directions and processing the data.

[Problem to be solved by the invention]

Conventional eye movement imaging devices such as those mentioned above use COD consisting of hundreds of thousands of pixels, which is good for capturing clear images, but the scanning time for one frame is 33.3m5e.
c to 15.1m5ec. In contrast, the eyeball moves quickly, at 4 to 5 m5ec per degree of visual angle.

Therefore, there is a problem in that unless the scanning speed of the CCD is increased using a special scanning method, the course of eye movement cannot be accurately determined.

When the number of pixels is reduced in order to increase the scanning speed of one frame, there is a problem that the image is not sufficiently clear.

Furthermore, in conventional eye movement imaging devices, when illuminating the eyeball, the illumination device is not placed on the same axis as the patient's eyeball, but illuminates the eyeball from an oblique direction. Double adjustments were required: position adjustment and adjustment to accurately irradiate the pupil with infrared rays. Furthermore, when the eyeball moves from side to side, the movement height of the pupillary reflection image is not symmetrical, and in order to correct this, there is a problem that complicated correction calculations are required.

In order to solve the above problem, the axis of the illumination light to the eyeball was arranged so that it was optically coaxial with the lens optical axis of the matrix camera and the eyeball visual axis, but adjustments were made to make them optically coaxial. The device is large-scale, and although it is good as a basic medical research device, it is difficult to miniaturize it for use as a clinical testing device for use in outpatient treatment.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide an eye movement imaging device in which the eyeball is uniformly illuminated from an oblique direction and the resolution and sensitivity are not degraded.

An object of the present invention is to provide an eye movement imaging device that can be obtained as an extremely simple device because it captures eye movement as the movement of the pupil, and that does not require calculation of the image position or complicated image processing. do.

SUMMARY OF THE INVENTION An object of the present invention is to provide an eye movement imaging device in which the resolution or SZN ratio of an image on a solid-state image sensor of a matrix camera does not deteriorate even when the lens and solid-state image sensor of the matrix camera are made smaller.

An object of the present invention is to provide an eye movement imaging device that allows the movement of the center of gravity of a pupil image to be viewed as an eye movement movement.

[Means to solve the problem]

FIG. 1 shows a detailed illustrative block diagram of the invention.

In FIG. 1, 1 is an eyeball pupil image former, 2 is a matrix camera made of, for example, a solid-state image sensor, 3 is a matrix controller, 4 is an XY-axis value calculation device, and 5 is a data processing device.

The eyeball pupil image forming device 1 is a device for forming a pupil image by irradiating the entire eyeball with uniform light from approximately the same direction as the optical axis of the matrix camera.

The matrix camera 2 causes the optical signal to pass through the lens 17 of the matrix camera 2 and form an image on a solid-state image sensor as a pupil image.

Then, the solid-state image sensor is electrically windowed to reduce the number of pixels. The matrix controller 3 generates a clock signal, an XY scanning signal, and an output data signal for controlling the solid-state image sensor of the matrix camera 2.

The XY-axis value calculation device 4 includes an adder, a counter, and a register for obtaining the center of gravity of the pupil image of the eyeball.

The data processing device 5 calculates the XY coordinate values of the pupil image gravity center using a computer, and outputs the digital values as analog signals.

The analog signals obtained in this way serve as data for diagnosing the patient's illness.

[For production]

The operation based on the present invention will be explained with reference to FIG. FIG. 2 shows an explanatory diagram of the principle of the XY coordinate calculation procedure in the present invention.

In FIG. 2, reference numeral 33 indicates a pupil image taken by the matrix camera 2 using the eyeball pupil image forming device 1.

In the eyeball and pupil image forming device 1, illumination light uniformly enters the eyeball, and the light beam of the pupil image enters the solid-state image sensor of the matrix camera 2 by a dichroic mirror and is converted into an electrical signal. In the case of such uniform illumination, the resolution is somewhat inferior compared to the infrared point light source of this type of eye movement imaging device, but on the other hand, since no infrared reflecting mirror is used, the lens 17 This has the advantage of making full use of the light flux of the pupil image that enters the pupil image. therefore,
It is sufficient as a clinical device.

The solid-state image sensor of matrix camera 2 is electrically windowed, so only a certain range of the solid-state image sensor needs to be effectively scanned. The amount of time that can be captured can be shortened.

The matrix controller 3 forms and sends each signal for obtaining the center of gravity of the pupil image from the solid-state image sensor. X
The Yill'll value adding device 4 is as shown in FIG.
It is added as the X-axis value of each pixel corresponding to the pupil image 33 of the eyeball. The data processing device 5 compares the magnitude of the results obtained each time the X-axis values are horizontally scanned. That is, the X-axis value added in the first horizontal scan is 81, the X-axis value added in the second scan is 82, 83, S4... is added in the scan of the center O of the pupil image 33. The xH value is S. , and the X@ value added in the next scan is S. +1. Then, the X-axis values S1 and S2, S2 and S8, S3 and S4...
Compare the size of. Continuing this comparison, the X-axis value So added during scanning of the center O of the pupil image 33 is the maximum,
The X-axis value SO+1 added in the next scan is the X-axis position S
. becomes smaller.

Therefore, the pupil image 3 is calculated by the computer of the data processing device 5.
The X-axis value So, which is the center of 3, is found. The X-axis value So obtained by adding in this way is x! lII value S.

By dividing by the total number of pixels obtained, the X coordinate of the center of gravity of the pupil image 33 can be found.

Further, when the number of times the X-axis is scanned at this time is counted by a counter, this number becomes YFi[.

Since the movement of the eyeball can be obtained as XY coordinate values through simple calculations as described above, there is no need to perform image correction of the eyeball movement, and the movement of the eyeball can be accurately captured.

〔Example〕

FIG. 3 is a block diagram schematically illustrating an embodiment of the present invention.

Hereinafter, one embodiment of the present invention will be specifically described with reference to FIG.

In FIG. 3, 1 is an eyeball pupil image former, 2 is a matrix camera made of, for example, a solid-state image sensor, 3 is a matrix controller, 4 is an XY-axis value calculation device, 5 is a data processing device, 11 is an eyeball, 12 is a pupil, 13 is a visual axis, 14 is an illumination device that emits uniform light, 16 is a dichroic mirror that passes visible light and reflects reflected illumination light, 17
is the lens of matrix camera 2, 18 is the screen, 21 is the optical axis of lens 17 of matrix camera 2,
22 is an X counter, 23 is a Y counter, 24 is an X adder, 25 is a pixel number counter, 26 is an X shift register,
After the first value enters register I, when the next value enters register ■, the previous value is shifted into register H. 27
is the Y register, 28 is the pixel number register, 29 is the divider,
30 is a comparator, 31 is a subtracter, and the dotted line indicates a band projected as a light reflection image of the eyeball 11.

The eyeball pupil image forming device 1 is an illumination device 1 that emits uniform light.
4 and a dichroic mirror 16 for forming a pupillary reflection image of the eyeball 11. The light emitted from the illumination device 14 is irradiated onto the eyeball 11. The light beam from the pupil 12 is bent at a right angle by a dichroic mirror 16, focused by a lens 17, and enters the matrix camera 2.

The matrix camera 2 shortens the scanning time by electrically windowing and using only 10,000 pixels (100×100) out of dozens of pixels. Then, the pupil 12 caused by the illumination light is captured as a pupil image 33 and converted into an analog signal corresponding to each pixel.

The matrix controller 3 sends out a data signal DATA when there is a pupil image 33, a vertical synchronization signal, and a lock signal CLK necessary for X-axis scanning.

The XY-axis value calculation device 4 includes an X counter 22 and a Y counter 2.
3, an X adder 24, a pixel number counter 25, an X shift register 26, a Y register 27, and a pixel number register 28. The X counter 22 is the matrix camera 2
Corresponding to the X-direction scanning of the solid-state imaging device in , the clock CLK continues counting until all the X-axis scanning is completed, and then it is reset. The X counter 22 is transferred to the adder 24 in response to the next clock CLK to prepare for addition.

On the other hand, when the horizontal scan reaches a pixel corresponding to the pupil image 33 (see FIG. 2), a value of 1 is entered into the adder 24 and the pixel number counter 25. The adder 24 successively adds the contents of the X counter 22 and the value incremented by 1, and stores the result in the X register 26.

At the same time, the pixel number counter 25 counts the number of pixels, and the result is entered into the pixel number register 28.

For example, in the case shown in FIG. 4, if the pixels for the first X-axis coordinate in the pupil image 33 are added, the fourth
A pupil image 33 appears from the illustrated third scanning line.

3...5+6+7=18 Similarly for other Xn sequentially, 4...3+4+5+6+7+8+9=425...
・2+3+4+5+6+7+8+9+l0=546...
・・2÷3+4+5+6+7+8+9+10=547・
...2+3+4+5+6B+8+9+10=548・
...1+2+3+4+5+6+7+8+9+10+1
1=669...2+3+4+5+6+? +8+9+
1O=54 These values are temporarily stored in register I of register 26.
When the next value is entered, the previous value is shifted and entered into the register ■, and the previous value and new value are stored.

Then, the comparator 30 compares (subtracts) the value previously entered into the register 26 and the newly entered value, and when the comparison result changes from negative to positive, the comparator 30 sends a one-frame end signal. issue.

The number in the pixel number register 28 is equal to 1 output from the comparator 30.
Sent to the divider by the end of frame signal.

On the other hand, the vertical synchronization signal that is issued every time the X axis is scanned
At the same time as resetting the counter 22 and the pixel number counter 25, the Y counter is incremented by 1, and the value is transferred to the Y register 2.
Put it in 7.

Next, in the comparator 30, as shown in FIG.
When compared with the X-axis addition value 54 in the th horizontal scan, the difference is positive, and a signal to end the horizontal scan is sent, and the contents of the register ■ of the X shift register 26 are sent to the divider 29, and this value is applied to number register 28 number 1
Divide by 1 to get the X coordinate.

At this time, the Y register 27 contains 9 as the ninth horizontal scanning line, so the subtracter 31 automatically subtracts 1 and sets this as the Y9 mark.

Although the X and Y coordinates of the center of gravity of one frame of the pupil image are determined in this way, it is not necessary to perform horizontal scanning to the end.

Since the center of gravity position of the pupil image 33 determined by the present invention is an absolute value, a diagnostic result can be obtained without image correction.

FIG. 5 shows an explanatory diagram of the XY coordinate calculation procedure in another embodiment of the present invention.

Similar to the method shown in FIG. 2, in order to obtain the center of gravity of the pupil image 33, the number of scanning lines used to scan the center O of the pupil image 33 and the added value of the pupil image 33 at that time are determined. All you have to do is understand.

Therefore, as shown in Figure 5, X, /Y, X, /Y
,
It can be seen that it passes through the center of

However, X1=S1/2 (See Figure 2 for S)X2
= (S2 St )/2 Y is the scanning line width Once the scanning line at the center of the pupil image 33 is known, the subsequent calculations can be made from the illustration in FIG.

As shown in FIG. 4, when the number of horizontal scanning lines is small, the differential coefficient may continue to be O, but in reality, since the number of horizontal scanning lines is large, this rarely happens. However, in consideration of noise, etc., the number of scan lines to be compared is increased, and the point in time when the differential coefficient is O or the polarity changes continuously is detected, and the center line of the axis is determined from this detected value. You can also get it.

Further, in the embodiments shown in FIGS. 4 and 5, the X coordinate is determined from the value obtained by horizontal scanning, but the X coordinate can also be determined after the Y coordinate is determined from the value.

Note that when monitoring the eyeball movement, it is possible to monitor the movement of the pupil 12 as desired, or to accurately capture the movement of the eyeball 11 as the center of gravity of the pupil, that is, as a spot. This monitor can be configured so that the screen can be switched and viewed as needed.

[Effects of the Invention] According to the present invention, since the center of gravity of the pupil image of the eyeball is calculated as the position of the XY coordinates, there is no need to perform image correction since it is the absolute value of the movement of the eyeball, and accurate diagnosis can be made.

According to the present invention, by electrically windowing the solid-state image sensor of the matrix camera to reduce the number of pixels and further speeding up the scanning time, we have not only achieved a scanning time of 4 m5ec, but also made it possible to scan the pupil image. You can do it in about half.

Therefore, even rapid eye movements can be accurately measured.

According to the present invention, the image density decreases by electrically windowing the solid-state image sensor of the matrix camera to reduce the number of pixels, and by treating the image area as a pupil image with a large amount, the resolution increases to some extent. However, since only the center point of the pupil image is calculated, the S/N ratio can be improved regardless of the resolution, and the accuracy of diagnosis can be improved even without image correction. Can be done.

According to the present invention, there is no need to provide an infrared reflecting mirror, so it is possible to downsize and reduce the number of adjustment points.
It is possible to provide an inexpensive device for clinicians.

According to the present invention, it is possible to freely select and view the image of the eyeball or the moving point of the eyeball on the monitor as necessary.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the present invention, FIG. 2 is a diagram explaining the principle of the XY coordinate calculation procedure in the present invention, FIG. Calculation Procedure Explanation Diagram FIG. 5 shows an XY coordinate calculation procedure explanatory diagram in another embodiment of the present invention. In the figure, 1-.-Eyeball pupil image former 2-Matrix camera 3-Matrix controller 4--111--x y H value addition device 5-1--Data processing device 11--Eyeball 13 -Visual axis 14--Uniform illumination 16--Dichroi 17--Lens 21--Lens optical axis 23--Y counter 25- --- Pixel number counter 27 --- Y register 29 --- Divider 31 --- Subtractor Tsukmirror 19 --- Screen 22 --- X counter 24 --- X addition Device 26 - X shift register 28 - Pixel number register 30 - Comparator 33 - Pupil image 12 - Diagram 1 Figure 2 Figure

Claims (3)

[Claims] (1) In an eyeball movement imaging device that images eyeball movements, an eyeball and pupil image forming device 1 that forms a pupil image by illuminating the eyeballs.
a matrix camera 2 consisting of a solid-state image sensor that captures the pupil image formed by the eyeball pupil image former 1 and extracts it as an analog signal for each pixel; and a matrix camera 2 for scanning the image sensor of the matrix camera 2. A scanning clock signal, a matrix for obtaining a digital data signal from an image analog signal corresponding to one screen.
Controller 3; Based on the positional information of the pupil image calculated by An eye movement imaging device comprising: device 5; (2) The eyeball movement imaging device according to claim 1, wherein the light irradiated onto the eyeball 11 by the eyeball pupil image forming device 1 is uniform illumination. (3) The XY-axis value addition device 4 and the data processing device 5
is characterized by calculating the centroid value of the X-axis value or Y-axis value by determining the differential coefficient of the X-axis value or Y-axis value obtained by scanning the pupil image, and outputting it as an XY coordinate signal. The eye movement imaging device according to claim 1. (4) The eye movement imaging device according to claim 1, wherein the matrix camera 2 electrically windows the pixels of a solid-state image sensor.