JPH08266477A - Display device - Google Patents

Abstract

PURPOSE: To provide a display device which can analyze the state of an eyeball control system in a significantly shorter time when compared with calculation time in the past to reduce physiological burden on a user. CONSTITUTION: This apparatus has an eyeball motion measuring section 1 to measure motion of eyeballs of both or either one eye, a data analysis section 2 to analyze a data obtained by the eyeball motion measuring section 1 and a display section 3 to alter or control a display state based on the results of the data analysis section 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for analyzing a minute vibration obtained by paying attention to a minute amplitude of an eyeball included in an eyeball control system for controlling both eyes or a single eye.

[0002]

2. Description of the Related Art Various displays have been proposed and supplied to the market as devices for displaying information. Among the various displays, the main body is small and features a large screen, and for example, a display part is attached to the head, and a pseudo ambient environment is given as an image in the range covering the field of view, Head mounted display for consumer (He
ad Mount Display: HMD) has been developed and commercialized.

Further, in general, when the display is continuously viewed, the eyes are given a physiological change such that the concentration of the eyes is reduced due to accumulation of eye strain. It has been known. Therefore, it becomes necessary to evaluate the degree of eye strain of the user.

As a method of evaluating the degree of eye strain, there is a method of examining the eyeball control system. Up to now, the method of evaluating the eye control system has been proposed by Seiji Yoshino et al., IEICE, MBE 90-15, p41-48, 1990. There is a method to evaluate fatigue. A study based on such a basic analysis of eye movement is important in applying this eye movement as an interface.

This eye movement analysis device has been used in the field of ophthalmology and neuropsychiatry to measure the movement of the eye control system with a display device based on medical engineering (ME) to quantitatively determine the function and mental state of the eye. It is also being evaluated and diagnosed. Since this eye movement analysis device has such a function, it is also used for quantitative evaluation of visual psychological experiments in psychology.

Further, according to the analysis method of the eyeball control system having Eiji Yodogawa of the A / R Audio Visualization Laboratory Co., Ltd. as an applicant, according to the time-series measurement data of the eyeball control system, each control system is analyzed. It is described that the value can be efficiently quantified by obtaining the value of the fractal dimension and the time dependence of the fractal dimension and performing a quantitative diagnosis of a disease of the eye control system. This method is considered to be an excellent method in that the effective degree of freedom of the eye control system can be estimated.

[0007]

By the way, in the above-mentioned method, since the time dependence of the cross-correlation of the measured data has a complicated behavior, the movement of the eye control system is interpreted from the time dependence of the cross-correlation. Requires specialized knowledge. This method also calculates the time dependence of the frequency component of the binocular cross correlation from the Fourier transform of this cross correlation,
It is possible to evaluate eye fatigue, but these calculations require a lot of time, and the display of the results also requires a three-dimensional image display, which makes real-time measurement impossible. When it is actually performed, a high-speed computer is required, and a large amount of capital investment is required.

[0008] However, it is desired that fatigue of a user of an HMD or a viewer such as a display be measured in real time by Kansei engineering or the like. This is because the real-time measurement can reduce the physiological burden on the user who uses the HMD or the display.

Therefore, the present invention has been made in view of the above-mentioned circumstances, and analyzes the state of the eyeball control system in a significantly shorter time than the conventional calculation time, and the physiological condition of the user is analyzed. An object of the present invention is to provide a display device that can reduce the burden.

[0010]

In order to solve the above-mentioned problems, a display device according to the present invention is a microscopic image obtained by paying attention to a micro amplitude of an eyeball included in an eyeball control system for controlling both eyes or a single eye. In a display device that analyzes vibration, an eye movement measurement unit that measures the eye movement of both eyes or a single eye, a data analysis unit that analyzes the data obtained by the eye movement measurement unit, and a display based on the result of the data analysis unit And a display unit for changing and controlling the state.

[0011]

In the display device according to the present invention, the display unit is controlled according to the setting based on the result obtained by analyzing the data obtained by the eye movement measuring unit by the data analyzing unit, so that the user's fatigue can be coped with. It can be displayed in a user-friendly manner.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a display device according to the present invention will be described below with reference to the drawings. Here, this display device is applied to a display device called an HMD having an eye movement analysis function for analyzing a minute vibration obtained by paying attention to a minute amplitude of an eyeball included in an eyeball control system for controlling both eyes or a single eye. An example will be described.

The main applications of this HMD are personal televisions, various terminals, various personal computer displays and the like. High attention is always required for these devices, and about 90% of the time during use,
It is said that he is watching. Therefore, it is necessary for the user who has used the HMD to consider the influence of fatigue and the like caused by the use.

In addition to the above, even in a user who has conventionally used an image monitor and a display generally called a VDT (Visual Display Terminal), it is considered that the eye gaze strongly influences the eye function, particularly the congestion adjusting function. Therefore, consideration of the impact of use has become a problem.

By the way, the effect of fatigue due to the above HMD is, for example, when the movement of the head is not taken into consideration, because there is no motion parallax and the like due to self-movement and there is no coordinated movement of the eye movement and the movement of the head, fatigue due to this VDT. It has been proposed that different medical and ergonomic studies are needed.

In the quantitative analysis of the fatigue of the HMD, it is preferable to ask whether or not various speculations which have been qualitatively pointed out in the past are questioned when applied to various uses. The display device displays based on the results of the eye movement measurement unit 1 that measures the eye movement of both eyes or monocular, the data analysis unit 2 that analyzes the data obtained by the eye movement measurement unit 1, and the data analysis unit 2. It has the display part 3 which changes and controls a state.

As shown in FIG. 2A, for example, the eye movement measuring unit 1 uses the scleral reflection method to detect independent amplitudes in the horizontal and vertical directions of the left and right, and the sensors 1a and A / D.
It has a converter 1b. The sensor 1a detects the involuntary eye movement of the eyeball by the scleral reflection method. As a specific example, as shown in FIG. 2B, the sensor 1a irradiates the eyeball with infrared light from a light emitting diode 11 attached to, for example, an HMD mounted on the head, and the left and right photodiodes 12, At 13, the amount of reflected light at the boundary between the white eye and the black eye is detected. As a result, the involuntary eye movement of the eye appears in the outputs of the photodiodes 12 and 13. This detection output is sent to the A / D converter 1b. A / as electrical setting
The D converter 1b samples at a sampling frequency of 200 Hz, for example, and quantizes it with 12 bits. The time required for one measurement by the eye movement measuring unit 1 is 2 minutes 30
Seconds. The eye movement measuring unit 1 is mounted on a see-through type head mounted display (hereinafter, referred to as HMD).

The data analysis unit 2 includes, for example, a CPU and RA.
M, a numerical processor, etc. The data analysis unit 2 inputs the measurement data from the eye movement measurement unit 1 to the data analysis unit 2 in accordance with a predetermined effective number, and then inputs the number of calculation data. For example, every 1 second from these input data. A data string is generated every fixed time. The data analysis unit 2 calculates the standard deviation or the first-order entropy at regular time intervals. The data analysis unit 2 supplies this analysis data to the display unit 3.

As shown in FIG. 1, for example, the display unit 3 includes a display control unit 3a for controlling the parameter setting of the display state and the output of messages based on the analysis data supplied, and a display control unit 3a. It is composed of a message sending unit 3b for sending a message according to the control signal, and a display unit 3c for displaying information according to the control signal and information supplied from the display control unit 3a and the message sending unit 3b.

From the display section 3c to the eye movement measuring section 1
The arrow to indicates that the eye movement is measured via the display unit 3c. Next, the procedure of eye movement measurement and data analysis of the display device will be described with reference to the flowchart of FIG. 3 and also with reference to FIG. 1 as necessary.

In this eye movement measurement, the subject
Wear MD. The HMD is, for example, one having an optical viewing angle of 21 ° in the horizontal direction and 16 ° in the vertical direction. The subject wears the device under conditions where the outside world cannot be seen, and calibrates the eye movement measuring unit 1 on the HMD screen.

In step S1, measurement conditions for eye movement measurement are input. For this measurement condition, for example, a trial time for one measurement is set. The trial time is set to, for example, 2 minutes and 30 seconds. The number of trials is set to 4 times, for example. Therefore, the measurement time is 10 minutes in total. As a result, 120,000 points of data are obtained for each eye movement component.

Next, in step S2, eye movement measurement is performed. In the eye movement measurement, blinking and electrical correction of the eyeball position are performed several times for each trial. The eye movement measuring unit 1 supplies the electric signal of the reflected light amount obtained by the sensor 1a to the A / D converter 1b. The A / D converter 1b is
The involuntary eye movement data is converted into a 12-bit digital value and output to the data analysis unit 2.

Next, in step S3, the data analysis unit 2
Captures the involuntary eye movement data from the A / D converter 1b as time-series two-dimensional data. The measurement data taken in is subjected to a process of matching with a predetermined significant figure. By controlling the significant figures of this data, it is possible to shorten the calculation time performed in the subsequent stage. Then, it progresses to step S4.

In step S4, the number of calculation data is input, a data string is generated at constant time intervals such as every second, and the process proceeds to step S5. In step S5, the standard deviation or the first-order entropy based on the data for every fixed time is calculated.

The first-order entropy is the probability of taking the state i, P _i ,

[0027]

[Equation 1]

Calculation is performed based on the equation (1). Also, the n data (x _i , y _i ) consisting of bivariates are ranked (r _xi ,
r _yi ), Spearman's rank correlation coefficient r _S
Is

[0029]

[Equation 2]

It is obtained by the equation (2). Next, in step S6, the time dependence of the calculated entropy is plotted. The calculated data is output to the display control unit 3a of the display unit 3.

When the output is completed, the data analysis process is completed. By performing the data analysis in such a procedure, the calculation result can be obtained in a short time as compared with the conventional analysis using, for example, fractal dimension. Next, the display controller 3a evaluates the plotted data.

The plotted data as the measurement results are shown in FIGS. Here, FIG. 4 shows the HMD in FIG.
The average of the standard deviations of the respective components calculated for the standard deviations when the virtual image displayed on the display unit 3c is fixed and when the actual index is fixed in FIG. Is plotted and the time dependence is shown. The solid line of the symbol (□) shows the movement of the left eye, and the broken line of the symbol (◯) shows the movement of the right eye.

As shown in FIG. 4A, the average standard deviation value when the HMD is worn tends to increase with time in both eyes. The right eye (dominant eye) tends to be larger than the value of the left eye. On the other hand, as shown in FIG. 4B, when gazing at the actual index, the averaged standard deviation value tends to be stable at a large value, and the magnitude relationship between the left and right eyes is shown in FIG.
Although the relationship is opposite to that of (a), the difference as a relative value is small. However, it cannot be said that there is a significant difference between the standard deviation values of the left and right eyes.

When the Spearman rank correlation coefficient r _S is used to illustrate the correlation between the horizontal directions of both eyes for each trial (the number of data points is 30,000), the results shown in FIG. 5, for example, are obtained. Here, the solid line of the symbol (□) shows the movement of both eyes when the HMD is attached, and the broken line of the symbol (◯) shows the movement of both eyes with respect to the actual index.

When the HMD is attached, a weak correlation is shown in the positive correlation region. Also, the correlation with the actual index is
It shows that there is a correlation in the negative region. That is, it shows that the vergence motion, which is a non-conjugate motion, occurs in the region of the negative correlation coefficient. The measurement with respect to the actual index has a significant positive correlation, which reflects the occurrence of the conjugate movement, micro saccade. As a result of testing such a correlation, it has been found that the risk rate P is significant at 0.01%.

Finally, the first-order entropy obtained by the equation (1) is shown in FIG. Here, the symbol (□) indicates the left eye, and the symbol (◯) indicates the right eye. The solid line is HM
D shows the movement at the time of wearing, and the broken line shows the movement of the eye with respect to the actual index.

At the start of measurement, the entropy is relatively smaller when the HMD is attached than when the actual index is used. This indicates that the eyeball is controlled by convergence. The entropy of wearing HMD over time
It shows that the frequency of micro saccades increases monotonically and that it becomes difficult to concentrate the gaze with gaze. This result is consistent with the quantitative evaluation model of visual fatigue in which the subject has difficulty performing the task by following eye movements in a fatigued state, and the ratio of saccade in eye movements increases with fatigue. To do.

Further, as shown in this plot, the entropy of the right eye, which is the dominant eye, is relatively smaller than the entropy of the left eye, and the gaze position is concentrated. The entropy with respect to the actual index shown by the broken line does not show time dependence, and many low burst micro saccades against fatigue from the start of measurement and the micro saccade in the histogram which is another display method. This is consistent with the result of the generation of multiple peaks by and the positive correlation in the correlation coefficient.

Under such a condition that the outside world cannot be seen, the HMD
When wearing, the standard deviation and entropy increase monotonically, and a significant difference in left and right eye movements that is consistent with the dominant eye is obtained. In addition, a significant difference was obtained in the correlation coefficient for congestion, micro saccade, too. As described above, this display device evaluates the vergence movement by the time dependency of the correlation coefficient of the left and right horizontal eye movements, so that it is possible to predict that the state of the eye control system in which the vergence movement frequently occurs is easily fatigued. become. Then, the entropy calculation result can also quantify fatigue in a short time. In this way, the display device can quantitatively know the state of the user from the eye movement by measurement.

Therefore, by utilizing this fact, the display device determines the state of the user by the display control section 3a,
The display unit 3c is controlled so that the display matches the state of the user. The display control unit 3a uses the brightness, the resolution, which are the setting parameters of the display unit 3c,
The color temperature, contrast, etc. are adjusted to be optimum for the user. The display control unit 3a also supplies a control signal to the message sending unit 3b so as to send a message according to the user's fatigue level. The message sending unit 3b supplies the display unit 3c with a warning message, for example, such that the display is temporarily blinked or a warning character such as a pattern such as a character or a picture is displayed. This allows the user to know his / her own state.

With the above configuration, for example, by controlling the significant figures of the data and controlling the display section based on the results from the data analysis section and the method of calculating the primary entropy. In comparison with conventional fractal dimension (correlation dimension), the time can be shortened significantly, and this measurement can be applied to real-time fatigue measurement to measure the user's condition quantitatively from eye movements while responding to eye strain. It is possible to control the display. As a result, it is possible to quickly reduce the physiological burden on the user and the viewer, and it is possible to provide an HMD as an eye-friendly display device.

[0042]

In the display device according to the present invention, the display means is controlled based on the results from the data analysis means and the data analysis means using, for example, the method of controlling the significant figures of the data and calculating the primary entropy. This can significantly reduce the time compared to the conventional fractal dimension (correlation dimension) measurement, and this measurement can be applied to real-time fatigue measurement to quantitatively know the user's state from eye movements while displaying the user's display. The user can be informed while controlling according to the state. As a result, it is possible to quickly reduce the physiological burden on the user and the viewer, and it is possible to provide an HMD as an eye-friendly display device.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of a display device according to the present invention.

FIG. 2 is a diagram showing a configuration of an eye movement measuring section of the display device.

FIG. 3 is a flowchart illustrating operations of an eye movement measurement unit and a data analysis unit of the display device.

FIG. 4 is a graph showing the average standard deviation measured with the display device over time.

FIG. 5 is a graph showing Spearman rank correlation coefficients measured with the display device over time.

FIG. 6 is a graph showing entropy measured by the display device over time.

[Explanation of symbols]

 1 Eye Movement Measuring Section 2 Data Analysis Section 3 Display Section 3a Display Control Section 3b Message Sending Section 3c Display Section

Claims (4)

[Claims] 1. A display device for analyzing a minute vibration obtained by paying attention to a minute amplitude of an eyeball included in an eyeball control system for controlling both eyes or a single eye, wherein an eye movement for measuring an eye movement of the both eyes or the single eye. A display device comprising: a measuring means; a data analyzing means for analyzing data obtained by the eye movement measuring means; and a display means for changing and controlling a display state based on a result of the data analyzing means. 2. The display means includes display control means for controlling setting parameters relating to display based on the result of the data analysis means, and display means for displaying in a state according to the setting parameters from the display control means. 2. The display device according to claim 1, further comprising a message supply unit that supplies a message corresponding to the control content of the display control unit to the display unit. 3. The display device according to claim 1, wherein the data analysis means calculates a Spearman rank correlation coefficient and / or a first-order entropy to analyze the motion. 4. The display device according to claim 2, wherein brightness, resolution, color temperature and contrast of the display means are used as the setting parameters.