JP2002355238A - Blink detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blink detector which can stably detect the number of blinks suppressing individual difference of blink detection generated by observers and variation of detection accuracy generated by various factors during detection. SOLUTION: When the detecting part 4 of this blink detector detects a blink, the maximum value of quantity of reflection light is updated to the quantity at that time. When the detecting part 4 detects no blink, the minimum value of quantity of reflection light is updated to the quantity at that time. Like that, because the maximum and minimum values of quantity of reflection light to be important factors for judging existence of blinks change from moment to moment corresponding to changes of quantity of reflection light captured by the blink sensor, blinks can be correctly detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blink detection device for analyzing psychological characteristics and realizing operations of various devices by blinking.

[0002]

Heretofore, as this kind of blink detection device, there has been known a system in which a weak infrared ray is radiated to the eyes and the reflected light is detected by a light receiving means. For example, as shown in FIG. 8, in addition to a blink sensor unit 3 in which an infrared light emitting diode 1 as a light projecting unit and a photodiode 2 as a light receiving unit are juxtaposed, a detection signal from the blink sensor unit 3 is provided. And a blink detection unit 4 that detects and outputs the blink of the observer. The blink sensor unit 3 converts the amount of reflected light received by the photodiode 2 into an electrical detection signal and outputs it to the blink detection unit 4 when the eye E is irradiated with weak infrared light from the infrared light emitting diode 1. The blink detection unit 4 blinks using the phenomenon that the reflected light amount of the photodiode 2 when the upper eyelid S1 is closed to the lower eyelid S2 side and the reflected light amount of the photodiode 2 when the upper eyelid S1 is opened greatly change. Is detected.

[0003] In addition, as a device for detecting blinking, for example, Japanese Patent Application Laid-Open No.
JP-A-00-39438 discloses a method of detecting changes in eyelids by image processing.
As disclosed in Japanese Patent No. -11675, there is a method for detecting distortion around the eyes accompanying blinking, and a method for detecting changes in muscle potential caused by blinking by attaching biological electrodes to eyes. . In particular, as shown in FIG. 9, the detection method based on the image processing includes a ring-shaped infrared light source 11 for illuminating the eye E with infrared light, and an objective lens at the center of the infrared light source 11.
And a camera 13 as an imaging device in which the
By photographing the movement of the camera with the camera 13, FIG.
The presence or absence of blinking is detected based on a change in the image when the eye E is opened as shown in FIG. 10 and a change in the image when the eye E is closed as shown in FIG. Various detection methods other than those shown in FIG. 9 are conceivable for the detection method based on the image processing regarding the arrangement and shape of the illumination unit such as the infrared light source 11 and the camera 13. However, these various types tend to be large-scale and increase the manufacturing cost.

As shown in FIG. 8, a method in which a weak infrared ray is applied to the eye E, the change in the amount of reflected light is captured by the photodiode 2, and the blink detector 4 detects the blink is a manufacturing cost per set. Is an excellent method as a blink detection device. However, since the change in the amount of reflected infrared light is used, the amount of reflected light varies depending on the color of the observer's skin, the difference in the amount of light from the eyelids varies depending on the degree of dryness of the corneal surface, and the position of the glasses frame is shifted. And the position of the blink sensor unit 3 attached to this glasses frame changes, and it is detected through a filter of a glasses lens or stereo glasses,
There has been such a problem that the change in the amount of reflected light captured by the blink sensor unit 3 becomes extremely small. Therefore, it is necessary to make individual adjustments depending on each observer or whether or not glasses are worn.

The present invention is intended to solve such a problem, and suppresses individual differences in blink detection that occur to each observer and fluctuations in detection accuracy caused by various factors during detection, thereby achieving stable blinking. It is an object of the present invention to provide a blink detection device that enables detection.

[0006]

According to a first aspect of the present invention, there is provided a blink detection apparatus which irradiates an infrared ray to an eye of an observer, detects a change in the amount of reflected light, and outputs a detection signal. In a blink detection device including a blink sensor unit that blinks and a blink detection unit that detects blink based on a detection signal from the blink sensor unit, when the change in the reflected light amount is increasing, the value of the reflected light amount at that time If the value obtained by comparing with the minimum value of the reflected light amount is equal to or greater than the predetermined reflected light amount difference,
While detecting the blinking and updating the maximum value of the reflected light amount, if the change in the reflected light amount is decreasing, the value obtained by comparing the value of the reflected light amount at that time with the maximum value of the reflected light amount is: If the difference between the reflected light amounts is equal to or greater than a predetermined difference, the blink detection unit is configured to detect that the blinking has not occurred and update the minimum value of the reflected light amount.

In this way, when the blink detecting unit detects that blinking, the maximum value of the reflected light amount is updated to the value of the reflected light amount at that time. When the blink detecting unit detects that no blinking has occurred, the minimum value of the reflected light amount is updated to the value of the reflected light amount at that time. As described above, the maximum value and the minimum value of the reflected light amount, which are important factors in determining the presence or absence of blinking, change every moment in accordance with the change in the reflected light amount captured by the blinking sensor unit. Even if the baseline of the amount of reflected light fluctuates when it is not performed, or if the amplitude of the amount of reflected light fluctuates each time blinking is performed, blink detection can be performed correctly.

According to a second aspect of the present invention, in the blink detection device according to the first aspect, when the change in the amount of reflected light after detecting the blinking is decreasing, the value of the amount of reflected light and the value of the amount of reflected light at that time are reduced. If the value compared with the maximum value is equal to or less than the predetermined reflected light amount difference, it is ignored, and if the change in the reflected light amount after detecting that it is not blinking is increasing, the reflected light amount at that time is increased. The blink detection unit is configured to ignore a value obtained by comparing a value of the reflected light amount with the minimum value of the reflected light amount if the difference is equal to or less than the predetermined reflected light amount difference.

In this way, when the change in the amount of reflected light is reduced after the blinking is detected, the value obtained by comparing the value of the amount of reflected light at that time with the maximum value of the amount of reflected light is reflected. Until the light intensity difference is reached, it is assumed that the person blinks ignoring this, and conversely, after detecting that it is not blinking,
Even if the change in the reflected light amount is increasing, it does not blink, ignoring this, until the value comparing the value of the reflected light amount at that time and the minimum value of the reflected light amount reaches the reflected light amount difference. Therefore, even if noise is mixed in the detection signal from the blink sensor unit and the amount of reflected light is finely increased or decreased, accurate blink detection can be performed ignoring this.

According to a third aspect of the present invention, in the blink detection device according to the first aspect, the blink detection unit calculates an average value of a difference in reflected light amounts from a change in reflected light amounts at the time of blinking a plurality of waveforms earlier. The predetermined reflection light amount difference is updated with a value having a range of 20 to 80% of the average value.

With this configuration, the reflected light amount difference is updated as needed based on the change in the reflected light amount at the time of the most recent blink detection of a plurality of waveforms earlier. The light amount difference fluctuates accordingly, and good blink detection can be performed.

According to a fourth aspect of the present invention, in the blink detection device according to any one of the first to third aspects, the blink sensor unit is mounted on an eyeglass frame.

With this configuration, it is possible to perform blink detection on the observer while the blink sensor unit is attached to the glasses frame, so that the blink detection result obtained by the blink detector is input to an information input device or an information input device. It can be used to evaluate psychological conditions such as dozing and interest.

According to a fifth aspect of the present invention, in the blink detection device according to any one of the first to third aspects, the blink sensor unit is mounted on a monocular or binocular head mounted display.

With this configuration, it is possible to perform blink detection on the observer while the blink sensor unit is mounted on the monocular or binocular head mounted display, so that the blink detection result obtained by the blink detector is obtained. Can be used for an information input device or for evaluating a psychological state such as dozing or interest.

According to a sixth aspect of the present invention, in the blink detection device according to the fourth or fifth aspect, an output from the blink sensor section or the blink detection section is wirelessly transmitted.

This makes it possible to wirelessly transmit the output from the blink sensor unit or the blink detection unit without using a cable as the connection means.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a preferred embodiment of a blink detecting device according to the present invention. FIG.
5 show a first embodiment of the present invention. In FIG. 1 showing the overall configuration of the apparatus, the configuration as a blink sensor unit 3 is exactly the same as that shown in FIG. This is configured by arranging an infrared light emitting diode 1 as light emitting means and a photodiode 2 as light receiving means in parallel. Then, the blink sensor unit 3 irradiates the eye E with weak infrared light from the infrared light emitting diode 1, captures a change in the amount of reflected light with the photodiode 2, and generates a blink detection unit 4 as an electrical detection signal.
It has the function of outputting to

On the other hand, the blink detecting section 4 has a function of detecting and outputting an observer's blink in accordance with an algorithm described later, which is a feature of the present invention. As means for embodying such a function, the blink detection unit 4 first makes the observer consciously blink, and based on the change in the amount of reflected light at that time, the reflection that serves as a reference when determining the presence or absence of blinking. Light intensity difference Δ
V, a minimum value Dmin of the amount of reflected light, and a maximum value Dmax of the amount of reflected light, respectively, as initial value setting means 21 for setting appropriate values for the observer, and the observer blinks in the second and subsequent measurements. Blink judgment means for judging whether or not it is performing
22. The blink determining means 22 includes a set value updating means 23 for updating the reflected light amount difference ΔV, the minimum value Dmin of the reflected light amount or the maximum value Dmax of the reflected light amount when a predetermined condition based on an algorithm described later is met. However, a specific updating procedure will be described later in detail.

Next, the operation of the above configuration will be described with reference to the flowchart shown in FIG. First, the infrared light emitting diode 1 and the photodiode 2 are connected to the eye E of the observer.
The blink sensor unit 3 is mounted in a state of facing the viewer, and at first, the observer is consciously blinked, and the detection signal from the blink sensor unit 3 at that time is taken into the blink detection unit 4 (step S).
1). At this time, if the upper eyelid S1 is open, the infrared light from the infrared light emitting diode 1 is mainly reflected on the eyeball and returns to the photodiode 2, but if the upper eyelid S1 is closed to the lower eyelid S2 side, The infrared light from the infrared light emitting diode 1 is mainly reflected on the upper eyelid S1 and returns to the photodiode 2. That is, the ratio of the skin (upper eyelid S1) occupying the infrared light reflection surface is:
When the eye E is closed, the reflectance is higher when the eye E is closed. However, since the reflectance of the skin is higher than the reflectance of the eyeball, when the eye E is open, the amount of reflected light captured by the photodiode 2 is relatively reduced and detected. When the voltage level of the signal is low and the eye E is closed, the amount of reflected light captured by the photodiode 2 is relatively increased, and the voltage level of the detection signal is high.

When the detection signal is input from the blink sensor unit 3 in this manner, the blink detection unit 4 determines the amount of reflected light at the time of blink and the voltage level of the detection signal if it is the first measurement in the next step S2. From the data determined in advance by experiment, the reflected light amount difference ΔV indicating the presence or absence of blinking
Initial values of the sensor output from the blink sensor unit 3, ie, the minimum value Dmin of the reflected light amount, and the sensor output from the blink sensor unit 3, ie, the maximum value Dmax of the reflected light amount, are set by the initial value setting means 21. (Step S3), the procedure returns to the step S1. Generally, if the change in the reflected light amount at the time of blinking is large, the reflected light amount difference ΔV becomes large in proportion thereto. The blink detection unit 4 captures the detection signal output from the blink sensor unit 3 as blink data at regular intervals, but for the second and subsequent blink data, the blink determination unit 22 does not go through the procedure of step S3. In step S4 and subsequent steps, the current data D (ti) captured at the current time (ti) is compared with the previous data D (ti-1) captured at the previous time (ti-1).

In this step S4, the value of the current data D (ti) fetched from the blink sensor 3 is
D (ti) ≧ = (ti-1)
When the relationship D (ti-1) is established, that is, when the change in the amount of reflected light captured by the photodiode 2 is increasing, the process proceeds to step S5, where the current data D (ti) at this time is changed. A value D (ti) -Dmin obtained by subtracting the minimum value Dmin of the reflected light amount from the value is a predetermined reflected light amount difference Δ
It is determined whether it is V or more. Then, a value D (t) obtained by comparing the current data D (ti) with the minimum value Dmin of the reflected light amount is obtained.
i) If -Dmin is greater than or equal to the reflected light amount difference ΔV, it is determined in the next step S6 that the eye E is in a blinking state with the eye E closed, and the maximum value Dmax of the reflected light amount is set by the set value updating means 23. Update to the value of the current data D (ti). At the same time, the process proceeds to step S9, where the set value updating means 23
Using the change in the waveform of the blink data at the time of blink detection three to three times earlier, the average value is calculated from the difference Dmax-Dmin between the maximum value Dmax and the minimum value Dmin of the reflected light amount at each blink detection, and the reflected light amount is calculated. Update the difference ΔV. The value of the reflected light amount difference ΔV updated at this time is 20 to 80% obtained by multiplying the average value of the reflected light amount difference Dmax−Dmin by a predetermined multiplication factor.
Value of the order. The multiplying rate increases as the waveform of the blink data at the time of each blink detection is stabilized.
When the update of the reflected light amount difference ΔV is completed, the process returns to the procedure of step S <b> 1 to acquire the next blink data from the blink sensor unit 3.

On the other hand, in step S4, the value of the current data D (ti) fetched from the blink sensor unit 3 is smaller than the value of the previous data D (ti-1), and D (ti) <D (ti-1). )
If the following relationship is established, that is, if the change in the amount of reflected light captured by the photodiode 2 is decreasing, the procedure moves to step S7, and the value of the current data D (ti) is changed from the maximum value Dmax of the amount of reflected light. Subtracted value Dmax-D (ti)
Is greater than or equal to a predetermined reflected light amount difference ΔV. Then, the maximum value of the reflected light amount and the current data D (t
The value Dmax-D (ti) obtained by comparing i) with the reflected light amount difference ΔV
If so, it is determined in the next step S8 that the eye E is not blinking with the eye E opened, and the set value updating means 23 determines the minimum value Dmin of the reflected light amount as the current data D (ti). Update to the value of At the same time, the process proceeds to step S9, and the reflected light amount difference ΔV is updated as described above. Also in this case, when the update of the reflected light amount difference ΔV is completed, step S
Returning to the procedure 1, the next blink data is fetched from the blink sensor unit 3.

Next, an example in which blinking can be detected satisfactorily by the above configuration will be described with reference to waveform diagrams of FIGS. 3 to 5, and an example of conventional blink detection will be described with reference to FIG. In each of these figures, the voltage level of the detection signal from the blink sensor unit 3 with the passage of time is shown in the upper part, and the blink output from the blink detector 4 (ON is the state of blinking). , OFF is a state in which it does not blink).

FIG. 11 shows an example of conventional blink detection. As can be seen from this figure, the reflected light amount captured by the photodiode 2 has its pp (peak-peak) value and the maximum value Dm.
ax and the minimum value Dmin change every moment. Conventionally, since the reflected light amount difference ΔV value is fixed, when a small peak occurs in the light amount due to the reflection of the eyelashes or the like as in the section A and the voltage fluctuation is reduced, the blinking is performed from the blinking state (ON). State (OFF) cannot be detected correctly.

On the other hand, FIG. 3 shows an example of the detection of blinking in the present embodiment, in which the baseline G of the amount of reflected light when the photodiode 2 is not blinking and the change in amplitude at the time of blinking. Shows a case where there is a change in The former change in the baseline G is caused by the change in the amount of ambient background light, the change in the degree of drying of the corneal surface, and the change in the direction of the light source because the photodiode 2 detects the change in the amount of reflected infrared light. It is easy to occur when the face is turned to the face. Further, the latter amplitude change at the time of blinking is likely to occur due to drying of the corneal surface or displacement of the blinking sensor unit. In the present embodiment, the maximum value Dmax or the minimum value Dmin of the reflected light amount is obtained each time the blink detection unit 4 determines that there is no blink in step S6, or every time that it is determined that there is no blink in step S8.
Is updated as needed, so that the minimum value Dmin of the amount of reflected light increases as the voltage level of the baseline G increases, and the minimum value Dmin of the amount of reflected light also decreases as the voltage level of the baseline G decreases, and blinks. The detection is not affected by the fluctuation of the baseline G. In addition, the maximum value Dmax of the reflected light amount is also updated to a higher value when the peak value of the reflected light amount at the time of blink detection becomes higher, and conversely, when the peak value of the reflected light amount at the time of blink detection becomes lower, Updated to a minute lower. At the same time, in step S9, the reflected light amount difference ΔV is updated using the blink data at the time of the most recent blink detection two to three times before, so that good blink detection is possible even for the latter amplitude change. Becomes

FIG. 4 shows a case where there is a large amplitude change in the amount of reflected light at the time of each blink detection in this embodiment. Note that, in this figure, how the reflected light amount difference ΔV changes as the time t advances is indicated by a dash-dot line in an easy-to-understand manner. As is clear from this figure, when the fluctuation of the reflected light amount at the time of blink detection becomes larger to some extent than before, the reflected light amount difference ΔV is relatively large, depending on the relationship with the multiplication factor described above. When the fluctuation of the amount of reflected light at the time of blink detection becomes smaller to some extent than before,
The reflected light amount difference ΔV is updated to a relatively large value. As described above, since the reflected light amount difference ΔV is updated using the blink data at the time of the most recent blink detection two to three times before, even if the reflected light amount has a large amplitude change, the reflected light amount difference ΔV
Fluctuates accordingly, and good blink detection can be performed.

FIG. 5 shows a case where noise is mixed in the detection signal from the blink sensor unit 3. Such noise is likely to be caused by irregular reflection of eyelashes and makeup, noise of a circuit system, and the like. However, the difference between the value of the captured current data D (ti) and the maximum value Dmax or the minimum value Dmin of the reflected light amount is The variation is equal to or less than the reflected light amount difference ΔV, and is easily removed. Therefore, there is no false detection of blinking due to noise.

As described above, according to this embodiment, the blink sensor unit 3 that irradiates infrared rays to the observer's eyes, captures a change in the amount of reflected light, and outputs a detection signal, and the blink sensor unit 3
And a blink detection unit 4 that detects a blink based on a detection signal from the camera. The value of the reflected light amount D (ti) captured at the present time and the value of the reflected light amount D (ti− 1), if the change in the amount of reflected light captured by the blink sensor unit 3 is increasing, the value obtained by comparing the value D (ti) of the amount of reflected light at that time with the minimum value Dmin of the amount of reflected light is If the difference between the reflected light amounts is equal to or larger than the predetermined reflected light amount difference ΔV, the blinking is detected, and the maximum value Dmax of the reflected light amount is updated. If the value obtained by comparing the light quantity value D (ti) with the maximum reflected light quantity Dmax is equal to or greater than a predetermined reflected light quantity difference ΔV, it is detected that blinking has not occurred, and the minimum reflected light quantity D
The blink detection unit 4 is configured to update min.

In this way, when the blink detector 4 detects that the person is blinking, the maximum value Dmax of the reflected light amount is updated to the value D (ti) of the reflected light amount at that time. When the blink detector 4 detects that the person is not blinking, the minimum value Dmin of the reflected light amount is set to the value D (ti) of the reflected light amount at that time.
Update to As described above, the maximum value Dmax and the minimum value Dmin of the amount of reflected light, which are important factors in determining the presence or absence of blinking,
Changes momentarily according to the change in the amount of reflected light captured by the blink sensor unit 3, so that the base line G of the amount of reflected light particularly when not blinking fluctuates, and the amplitude of the amount of reflected light every time a blink is performed Can be correctly detected even if the value fluctuates. Therefore, it is possible to suppress individual differences in blink detection that occur for each observer and fluctuations in detection accuracy caused by various factors during detection, and perform stable blink detection.

When the change in the amount of reflected light after detecting the blinking is reduced, the blink detector 4 of the present embodiment determines the value D (ti) of the reflected light amount and the value of the reflected light amount. If the value compared with the maximum value Dmax is equal to or smaller than the predetermined reflected light amount difference ΔV, the difference is ignored, and if the change in the reflected light amount after detecting that it is not blinking is increasing, If a value obtained by comparing the value D (ti) of the reflected light amount at that time with the minimum value Dmin of the reflected light amount is equal to or smaller than a predetermined reflected light amount difference, the difference is ignored.

In this way, when the change in the amount of reflected light is reduced after detecting the blinking, the value D (ti) of the amount of reflected light and the maximum value Dmax of the amount of reflected light at that time are determined. Until the compared value reaches the reflected light amount difference ΔV, it is assumed that blinking is ignored ignoring this, and conversely, if the change in reflected light amount is increasing after detecting that there is no blinking Also, it is assumed that blinking is ignored until the value obtained by comparing the value D (ti) of the reflected light amount at that time with the minimum value Dmin of the reflected light amount reaches the reflected light amount difference ΔV. Even if noise is mixed into the detection signal from the blink sensor unit 3 and the amount of reflected light is finely increased or decreased, accurate blink detection can be performed ignoring this.

Further, in this embodiment, the average value of the difference between the reflected light amounts is calculated from the change in the reflected light amount at the time of blinking a plurality of waveforms earlier, and the average value is a value having a width of 20 to 80% of the average value. To update a predetermined reflected light amount difference,
The blink detection unit 4 is configured.

With this configuration, the reflected light amount difference ΔV is updated as needed based on the change in the reflected light amount at the time of the most recent blink detection for a plurality of waveforms before. Therefore, even if the reflected light amount has a large amplitude change, The reflected light amount difference ΔV fluctuates accordingly, and good blink detection can be performed.

Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, in the blink detection device proposed in the first embodiment, the blink sensor unit 3 is attached to the spectacle frame 21, and in this case, one of the lens units 22 held by the spectacle frame 21 is attached. After passing through, the photodiode 2 receives the amount of reflected light.
The eyeglass frame 21 uses a flexible arm 23 having a flexible direction that can be freely adjusted, so that the blink sensor unit 3 can be easily directed toward the observer's eyes. Also,
The blink sensor 3 and the blink detector 4 are connected by a cable 24. Note that the blink sensor unit 3 can be sandwiched between the eyeglass frames 21 using a clip or the like (not shown).

By attaching the blink sensor unit 3 to the spectacle frame 21 in this manner, it is possible to perform blink detection for an observer with the blink sensor unit 3 attached to the spectacle frame 21. Therefore, the result of blink detection obtained by the blink detector 4 can be used for an information input device or for evaluating a mental state such as dozing or interest.

FIG. 7 shows a third embodiment of the present invention. In the blink detection device proposed in the first embodiment, the blink sensor unit 3 is mounted on a monocular head mounted display (HMD) 31. This HM
D31 includes a mounting part 32 to the head of the observer and a display device 33 provided at a position facing the eye E of the observer. The display device 33 and the blink sensor unit 3 are provided integrally. Although the monocular HMD 31 is shown here, the binocular HMD 31 is used.
Of course, it can be used for MD31. Based on the output from the blink detector 4, the blinking operation can be used instead of clicking the mouse while looking at the display device 33, or can be used to evaluate the degree of concentration on the display device 33.

By attaching the blink sensor unit 3 to the monocular or binocular HMD 31 as described above, it is possible to detect the blink for the observer while the blink sensor unit 3 is attached to the monocular or binocular HMD 31. Can do it. Therefore, the result of blink detection obtained by the blink detector 4 can be used for an information input device or for evaluating a mental state such as dozing or interest.

Further, in the second and third embodiments, it is possible to incorporate a battery as a drive power supply in the blink sensor unit 3 and transmit the output wirelessly. This makes it possible to wirelessly transmit the detection signal from the blink sensor unit 3 without using a cable as the connection means. Further, not only the blink sensor unit 3 but also the blink detection unit 4 may be mounted on the eyeglass frame 21 or the HMD 31. In this case, if the output from the blink detection unit 4 is transmitted wirelessly, the detection signal from the blink detection unit 4 can be transmitted wirelessly without using a cable as a connection unit.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made.

[0041]

According to the blink detection device of the first aspect, it is possible to suppress individual differences in the blink detection that occur to each observer and fluctuations in the detection accuracy caused by various factors during the detection, thereby enabling stable blink detection. it can.

According to the second aspect of the present invention, even if noise is mixed in the detection signal from the blink sensor unit, accurate blink detection can be performed by ignoring the noise.

According to the blink detecting device of the third aspect, it is possible to perform a good blink detection even if the reflected light amount has a large amplitude change.

According to the blink detecting device of the fourth aspect, the result of blink detection obtained by the blink detecting unit can be used for an information input device or for evaluating a mental state such as dozing or interest.

According to the blink detecting device of the fifth aspect, the result of blink detection obtained by the blink detecting unit can be used for an information input device or for evaluating a mental state such as dozing or interest.

According to the blink detecting device of claim 6, the output from the blink sensor unit or the blink detecting unit can be transmitted wirelessly without using a cable as the connecting means.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention and showing a functional configuration of a blink detection device.

FIG. 2 is a flowchart showing an operation procedure in the blink detection unit.

FIG. 3 is a waveform chart showing a voltage level of a detection signal and a blink detection state in a case where there is a change in a baseline and an amplitude change of a reflected light amount.

FIG. 4 is a waveform chart showing a voltage level of a detection signal and a blink detection state when the amplitude change of the reflected light amount fluctuates greatly.

FIG. 5 is a waveform diagram showing a voltage level of a detection signal and a blink detection state when noise is mixed therein;

FIG. 6 shows the second embodiment of the present invention, and is a perspective view showing a state where a blink sensor unit is attached to an eyeglass frame.

FIG. 7 shows the third embodiment of the present invention, and is a front view showing a state in which a blink sensor unit is attached to a monocular head mounted display.

FIG. 8 is a schematic explanatory view of a device for detecting blinking by irradiating a weak infrared ray to an eye in a conventional example.

FIG. 9 is a schematic explanatory diagram of an apparatus for detecting blinks by image processing in another conventional example.

10A and 10B show images of the device shown in FIG. 9, wherein FIG. 10A shows a state when the eyes are opened, and FIG. 10B shows a state when the eyes are closed.

FIG. 11 is a waveform diagram showing a voltage level of a detection signal and a blink detection state in a conventional blink detection example.

[Explanation of symbols]

 3 Blink sensor unit 4 Blink detection unit 21 Glasses frame 31 Head mounted display

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuichi Yamanoue 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Corporation Research Institute (72) Inventor Masato Okui 1-110 Kinuta, Setagaya-ku, Tokyo No. Japan Broadcasting Corporation Broadcasting Research Institute (72) Inventor Kenichiro Takei 619 Yashiroda, Kosudo-cho, Nakagabara-gun, Niigata Prefecture F-term in Takei Kiki Kogyo Co., Ltd.

Claims (6)

[Claims] 1. A blink sensor unit that irradiates an infrared ray to an observer's eye, captures a change in the amount of reflected light, and outputs a detection signal, and a blink detection unit that detects a blink based on the detection signal from the blink sensor unit. In the blink detection device provided with, the blink detection unit, when the change in reflected light amount is increasing,
If the value obtained by comparing the value of the reflected light amount and the minimum value of the reflected light amount at that time is equal to or greater than a predetermined reflected light amount difference, it is detected that the subject is blinking, and the maximum value of the reflected light amount is updated. If the change in the amount of reflected light is decreasing, if the value obtained by comparing the value of the amount of reflected light at that time with the maximum value of the amount of reflected light is greater than or equal to a predetermined difference in the amount of reflected light, it is detected that no blinking has occurred. And updating the minimum value of the amount of reflected light. 2. When the change in the amount of reflected light after detecting blinking is decreasing, a value obtained by comparing the value of the amount of reflected light at that time with the maximum value of the amount of reflected light is determined in advance. If the difference in reflected light amount is less than the difference in reflected light amount, it is ignored, and if the change in reflected light amount after detecting that it is not blinking is increasing,
The blink detection unit is configured to ignore a value obtained by comparing a value of the reflected light amount and a minimum value of the reflected light amount at that time if the difference is equal to or less than the predetermined reflected light amount difference. The blink detection device according to 1. 3. The blink detection unit calculates an average value of a difference in reflected light amount from a change in reflected light amount at the time of blinking a plurality of waveforms earlier, and calculates a value having a range of 20 to 80% of the average value. 2. The blink detection device according to claim 1, wherein the predetermined reflected light amount difference is updated. 4. The blink detection device according to claim 1, wherein the blink sensor unit is mounted on an eyeglass frame. 5. The blink detection device according to claim 1, wherein the blink sensor unit is mounted on a monocular or binocular head mounted display. 6. The blink detection device according to claim 4, wherein an output from the blink sensor unit or the blink detection unit is wirelessly transmitted.