JP3038375B1 - Line-of-sight direction detection method and its detection device - Google Patents

Abstract

Kind Code: A1 A new gaze direction detection device and gaze direction for correcting a displacement of a head-mounted unit caused when measuring a gaze direction using a scleral reflection method and detecting an accurate gaze direction. A direction detection method is provided. SOLUTION: An infrared LED 1 and infrared phototransistors 3 and 4 are located on the right side of the center of the head mounted unit.
Are provided, and an infrared LED 2 and infrared phototransistors 5 and 6 are provided on the left side from the center of the head-mounted unit. An additional infrared LED 9 and an infrared phototransistor 10 are provided, and the infrared phototransistor receives the intensity of the reflected infrared light from the infrared LED 9 caused by the difference in reflectance between the upper eyelid 11 and the cornea 7 of the eyeball.・ Measure to detect the displacement of the head mounted unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gaze direction detecting device and a detection method thereof, and more particularly, to a gaze direction detecting device which can be suitably used for a head-mounted interface device in a body-mounted computer. And its detection method.

[0002]

2. Description of the Related Art With the current evolution of computers, personal computers are becoming smaller and more sophisticated.
In particular, in recent years, a body-worn computer has been researched and developed as a system that enables a person who is working with both hands to easily input and acquire appropriate information. The present inventors have been researching and developing a head-mounted interface device in order to develop a body-mounted computer that does not particularly hinder work. This interface needs to include a gaze direction detecting device from the viewpoint of operating the device with the gaze. As a method of detecting the line of sight, the sclera reflection method is often used from the viewpoint of the simplicity of the apparatus and the line of sight detection accuracy.

In the sclera reflection method, a light emitting element such as an infrared LED and a light receiving element such as an infrared phototransistor are provided on the left and right sides from the center of the head mounted unit, respectively, and light emitted from the light emitting element is provided. Irradiate the eyeball, receive the reflected light from the eyeball with the light receiving element, measure the intensity of the reflected light due to the reflectance difference between the sclera and cornea of the eyeball and detect the gaze direction Is the way.

FIG. 1 is a diagram for explaining an example of a gaze direction detecting method using the sclera reflection method. In the gaze direction detection method shown in FIG. 1, an infrared LED 1 and infrared phototransistors 3 and 4 are provided on the left side from the center of the head mounted unit, and an infrared LED 2 and an infrared photo transistor are provided on the right side from the center of the head mounted unit. A gaze direction detecting device provided with 5 and 6 is used.

For example, as shown in FIG. 1, assuming that the line of sight is to the right, infrared rays emitted from an infrared LED 1 provided on the left side of the head-mounted unit emit sclera (white eyes) having a high reflectance. 8) instead of the corneal portion (black eye) 7 having a low reflectance, and the amount of reflected infrared rays received by the infrared phototransistors 3 and 4 also provided on the left side of the head mounted unit is reduced. On the other hand, the infrared rays emitted from the infrared LED 2 provided on the right side of the head-mounted unit are also provided on the right side of the head-mounted unit because the ratio of the infrared rays reflected by the sclera section 8 having high reflectance is increased. The amount of reflected infrared rays received by the infrared phototransistors 5 and 6 increases.

Similarly, if the line of sight is directed upward, the amount of reflected infrared light received by the infrared phototransistors 3 and 5 decreases, and the amount of reflected infrared light received by the infrared phototransistors 4 and 6 increases. I do. Therefore, by measuring the amount of reflected infrared light received by each infrared phototransistor, it is possible to detect which direction the line of sight is facing.

[0007]

However, detection of the direction of the line of sight by the sclera reflection method as described above uses infrared rays L.
It is necessary to use a head-mounted unit provided with a light-emitting element such as an ED and a light-receiving element such as an infrared phototransistor, and since it is actually glasses or goggles that are actually used as a head-mounted unit, There was a case where the head-mounted unit was vertically displaced from the initial position. If the head-mounted unit is displaced from the initial position in this way, the amount of reflected infrared rays changes, so that an accurate gaze direction cannot be detected. Furthermore, since it is not known that the head-mounted unit has deviated, there is a problem in that an incorrect gaze direction is continuously measured.

SUMMARY OF THE INVENTION The present invention provides a new gaze direction detecting device for correcting a displacement of a head-mounted unit that occurs when measuring a gaze direction using a scleral reflection method and detecting an accurate gaze direction. It is an object to provide a gaze direction detection method.

[0009]

According to a gaze direction detecting method of the present invention, a light emitting element and a light receiving element are provided in a head mounted unit, and light emitted from the light emitting element is radiated to an eyeball. A gaze direction detecting method for detecting the gaze direction by measuring the intensity of the reflected light caused by a difference in reflectance between the sclera and the cornea of the eyeball by receiving the reflected light of the light receiving element. An additional light-emitting element and a light-receiving element are separately provided on the upper and lower sides from the center of the head-mounted unit, and the light emitted from the additional light-emitting element to the upper eyelid and the cornea of the eyeball is reflected. By receiving the intensity of light with the additional light receiving element,
It is characterized in that the displacement of the head mounted unit is detected.

Further, the gaze direction detecting device of the present invention provides a head mounted unit having a light emitting element and a light receiving element, irradiating the light emitted from the light emitting element to the eyeball, and reflecting the light reflected from the eyeball. A gaze detection device that receives light with the light receiving element, measures the intensity of the reflected light caused by a reflectance difference between the sclera and the cornea of the eyeball, and detects the gaze direction, wherein the head Additional light-emitting elements and light-receiving elements for detecting a displacement of the head-mounted unit are provided separately on the upper and lower sides from the center of the head-mounted unit, and the light-receiving elements for detecting the line-of-sight direction Are provided on each of the left and right sides from the center of the head-mounted unit so as to detect the horizontal and vertical directions of the line of sight.

According to the gaze direction detecting method and the gaze direction detection device of the present invention, apart from the light emitting element and the light receiving element for detecting the gaze direction, an additional light emitting element and a light receiving element are arranged from the center of the head mounted unit. Since it is provided separately on each of the upper and lower sides, for example, when the head-mounted unit is at the correct position, reflection when irradiating the upper eyelid with light emitted from the additional light emitting element Light intensity,
The vertical displacement of the head mounted unit can be detected by measuring and comparing the intensity of the reflected light when irradiating the cornea of the eyeball when the head mounted unit is displaced downward. Therefore, it is possible to stably detect the line of sight by correcting the displacement of the head mounted unit.

Further, according to the gaze direction detecting device of the present invention, since a plurality of light receiving elements are provided on each of the left and right sides from the center of the head mounted unit, they will be described in the following "embodiments of the invention". So, not only in the vertical direction of the line of sight,
The left and right directions of the line of sight can also be detected.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments of the present invention. FIG. 2 is a conceptual diagram illustrating an example of the gaze direction detection method according to the present invention. FIG. 3 is a diagram showing an example of a block configuration of the gaze direction detection method and the detection device according to the present invention. The gaze direction detection method of the present invention shown in FIG. 2 includes the infrared LED 1 and the infrared phototransistors 3 and 4 on the left side of the head-mounted unit, as in the case of the gaze direction detection method described in the above “Conventional Technology”. A line-of-sight direction detecting device provided with an infrared LED 2 and infrared phototransistors 5 and 6 on the right side of the head-mounted unit is provided.
The gaze direction is detected by using a light emitting element and a light receiving element including D and infrared phototransistors.

Further, an infrared LED 9 as an additional light emitting element is provided above the head mounted unit of the gaze direction detecting device.
And an infrared phototransistor 10, which is an additional light receiving element, is provided below the head mounted unit, and the light emitting element and the light receiving element are used as a pair to detect a vertical displacement of the head mounted unit. I am trying to do it. Hereinafter, the gaze direction detecting method of the present invention will be specifically described with reference to FIGS.

The infrared LED 1 and the infrared LED 2 are connected to an infrared LED controller 11, and receive a signal from the infrared LED controller to irradiate the eyeball with infrared light having a predetermined power. When the infrared rays emitted from the infrared LEDs 1 and 2 irradiate the eyeball, a part of the infrared ray is reflected and becomes reflected light. Although the intensity of the reflected light varies depending on the reflectance of the illuminated portion of the eyeball, as described above, the reflectance of the sclera is greater than the reflectance of the cornea. The line-of-sight direction is detected by detecting and measuring in step 6.

For example, assuming that the line of sight is to the right as shown in FIG. 3, as described in "Prior Art",
Since the infrared light emitted from the infrared LED 1 is reflected by the cornea 7 having a low reflectance, the amount of reflected infrared light received by the infrared phototransistors 3 and 4 is reduced. On the other hand, since the infrared rays emitted from the infrared LED 2 are reflected by the sclera portion 8 having a high reflectance, the ratio of the infrared rays increases.
The amount of reflected infrared rays received by the infrared phototransistors 5 and 6 increases. Further, when the line of sight is directed upward, the amount of reflected infrared light received by the infrared phototransistors 3 and 5 decreases, and the amount of reflected infrared light received by the infrared phototransistors 4 and 6 increases.

The reflected infrared light received by each of the infrared phototransistors is converted into an electric signal having a magnitude corresponding to the amount of the reflected infrared light received by each infrared phototransistor, and then sent to a signal amplifier 12 for amplification. The signal is sent to the signal measuring device 13 and measured. In the gaze direction detection method of the present invention shown in FIG. 2, the left and right directions of the gaze are detected by detecting and comparing the amounts of reflected infrared rays detected by the infrared phototransistors 3 and 4 and the infrared phototransistors 5 and 6. The vertical direction of the line of sight is detected by detecting and comparing the amounts of reflected infrared rays detected by the infrared phototransistors 3 and 5 and the infrared phototransistors 4 and 6.

Therefore, in the signal measuring device 13, the position Hp of the line of sight in the left-right direction is calculated based on the following formula.
os and the vertical position Vpos of the line of sight are measured. Hpos = {(Sig.1 + Sig.2)-(Sig.3 + Sig.4) -Hoffset} × Hmag (1) Vpos = {(Sig.1 + Sig.3)-(Sig.2 + Sig. 4) -Voffset} × Vmag (2) Hoffset, Hmag, Voffs in the above equations (1) and (2)
et and Vmag are constants determined by the configuration and mode of the gaze direction detection device, and are measured and obtained in advance by adjustment (calibration) before measurement. Furthermore, Si
g.1 to 4 are electric signals converted from the reflected infrared rays received by the infrared phototransistors 3 to 6, respectively.

Next, the infrared LED controller 1
A predetermined signal is sent to the infrared LED 9 connected to 1,
An infrared ray having a predetermined power is irradiated toward the eyeball. This infrared ray is radiated to the upper eyelid 11 of the eyeball when the head-mounted unit is at the initial correct position, and when the head-mounted unit is shifted downward, the corneal part 7 of the eyeball is shifted. Is irradiated. As in the case of the sclera and cornea of the eyeball, since the reflectance of infrared rays is higher in the upper eyelid 11 of the eyeball than in the cornea 7 of the eyeball, the head-mounted unit is moved downward from the initial position. If the position shifts, the proportion of infrared rays radiated to the cornea 7 of the eyeball and reflected increases, so that the amount of reflected infrared rays detected by the infrared phototransistor 10 decreases.

The increase or decrease in the amount of the reflected infrared rays is detected by the infrared phototransistor 10. In the infrared phototransistor 10, this optical signal is converted into an electric signal, and then sent to the signal amplifier 22 in the same manner as described above. After being amplified to the size, it is sent to the deviation signal measuring device 24. In this shift signal measuring device 24, an infrared LED
Data relating to the amount of reflected infrared light from the upper eyelid 11 and the cornea 7 of the eyeball and the amount of reflected infrared light that is a mixture of the reflected infrared light and the reflected infrared light corresponding to each power of the infrared light emitted toward the eyeball from the eye 9 are input in advance. The position of the head-mounted unit is determined by performing an arithmetic process by comparing these data with a signal transmitted from the infrared LED controller 11 to the infrared LED 9 and the amount of reflected infrared light detected by the infrared phototransistor 10. To detect.

As described above, in FIG. 2, an infrared light L which is an additional light emitting element for detecting a displacement of the head mounted unit is shown.
An ED 10 is provided above the head-mounted unit, and an infrared phototransistor 1 which is also a pair of additional light receiving elements.
0 is provided below the head mounted unit, but the positional relationship in the vertical direction is not necessarily limited, and the infrared LED 9 is provided below the head mounted unit, The transistor 10 may be provided above the head mounted unit. That is, it is only necessary that these components are separately installed above and below the head mounted unit.

As the head-mounted unit in the present invention, ordinary glasses, goggles and the like can be used.
Therefore, in such a case, an infrared LED or an infrared phototransistor is provided on a frame such as the glasses.

[0023]

As described above, according to the gaze direction detecting method and apparatus of the present invention, the displacement of the head-mounted unit used in detecting the gaze direction by the so-called reflective sclera method is detected. be able to. Therefore, the shift of the head-mounted unit can be corrected during the detection of the gaze direction, so that the gaze direction can be stably detected.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram for explaining a method of detecting a gaze direction by a sclera reflection method.

FIG. 2 is a conceptual diagram illustrating a gaze direction detection method according to the present invention.

FIG. 3 is a diagram illustrating an example of a block configuration in a gaze direction detection method and apparatus according to the present invention.

[Explanation of symbols]

 1, 2, 9 Infrared LED 3, 4, 5, 6, 10 Infrared phototransistor 7 Cornea of eyeball 8 Sclera of eyeball 11 Upper eyelid of eyeball 21 Infrared LED controller 22 Signal amplifier 23 Signal measuring device 24 Displacement signal measurement apparatus

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01B 11/00-11/30 102 H04N 5/64

Claims (4)

(57) [Claims] A light-emitting element and a light-receiving element provided in the head-mounted unit, the light emitted from the light-emitting element is radiated to an eyeball, and the light reflected from the eyeball is received by the light-receiving element. A gaze direction detecting method for detecting a gaze direction by measuring the intensity of the reflected light caused by a reflectance difference between the sclera portion and the corneal portion, wherein an additional light emitting element and a light receiving element are provided on the head. Provided separately on each of the upper and lower sides from the center of the mounting unit, and the intensity of reflected light with respect to light emitted from the additional light emitting element to the upper eyelid and the cornea of the eyeball is received by the additional light receiving element. A gaze direction detecting method for detecting a displacement of the head-mounted unit. 2. The apparatus according to claim 1, wherein a plurality of light receiving elements for detecting the direction of the line of sight are provided on each of the left and right sides from the center of the head mounted unit, and the left and right and up and down directions of the line of sight are detected. The gaze direction detecting method according to claim 1, wherein 3. A light-emitting element and a light-receiving element are provided in a head-mounted unit, and light emitted from the light-emitting element is radiated to an eyeball, and reflected light from the eyeball is received by the light-receiving element. A gaze detecting device configured to detect the gaze direction by measuring the intensity of the reflected light caused by a reflectance difference between the sclera portion and the corneal portion, for detecting a displacement of the head-mounted unit. Additional light-emitting elements and light-receiving elements are provided separately on each of the upper and lower sides from the center of the head-mounted unit, and the light-receiving elements for detecting the line-of-sight direction are provided in the horizontal and vertical directions of the line of sight. A plurality of gaze direction detection devices are provided on each of the left and right sides from the center of the head-mounted unit so as to detect the gaze direction. 4. The gaze direction detecting device according to claim 3, wherein the light emitting element is an infrared LED, and the light receiving element is an infrared phototransistor.