JP7388507B2 - Surface-emitting laser for pupil or cornea position detection device, light source device, and eyeball tilt position detection device - Google Patents

Description

The present invention relates to a surface emitting laser for a pupil or cornea position detection device , a light source device, and an eyeball tilt position detection device.

In recent years, technologies and products related to virtual reality (VR) and augmented reality (AR) have been attracting attention. In particular, AR technology is expected to be applied to the industrial field as a means of displaying digital information in real space. In view of the fact that "people" who utilize AR technology acquire most of their cognitive information visually, glasses-type video display devices that can be used in behavioral (work) environments have been developed. Furthermore, as such a glasses-type image display device, a glasses-type image display device using a retinal drawing method that draws an image directly on a "person's" retina using a laser is known.

By the way, in glasses-type video display devices that use a retinal drawing method using a laser, the laser vignetting may occur on the outer periphery of the cornea or pupil in an action (work) environment that involves eye movement due to the size limitations of the cornea or pupil. This may occur, making it impossible to draw a specific image at a specific location.

To address these issues, we have developed a MEMS (Micro Electro Mechanical Systems) mirror that scans a laser on the eyeball in order to detect the position of the cornea and feed it back to the image drawing position, and a MEMS (Micro Electro Mechanical Systems) mirror that scans the laser on the eyeball and a mirror that detects the intensity of reflected light. Eye tracking technology that includes a photodetector and an electronic circuit that estimates the corneal position on the eyeball from the detected intensity has been disclosed (see, for example, Patent Document 1 and Non-Patent Document 1).

An object of the present invention is to provide a surface emitting laser for a pupil or corneal position detection device that can increase the amount of light and improve alignment accuracy.

A surface emitting laser for a pupil or corneal position detecting device according to one aspect of the disclosed technology is a surface emitting laser for a pupil or corneal position detecting device in which light is oscillated by an active layer and a reflecting mirror and emitted from a light exit surface via an optical element. In the surface emitting laser, light emitted from the optical element has an annular shape when viewed from a direction perpendicular to the light exit surface.

According to the embodiments of the present invention, it is possible to provide a surface emitting laser for a pupil or cornea position detection device that can increase the amount of light and improve alignment accuracy.

FIG. 1 is a diagram showing an example of the configuration of a pupil position detection device according to a first embodiment. FIG. 3 is a diagram illustrating an example of a pupil position detection operation according to the first embodiment, in which (a) is a diagram showing when the eyeball is facing forward, and (b) is a diagram showing when the eyeball is rotating. FIG. FIG. 2 is a block diagram illustrating an example of the hardware configuration of a processing unit according to the first embodiment. FIG. 2 is a diagram illustrating an example of the components of the processing unit according to the first embodiment using functional blocks. 7 is a flowchart illustrating an example of processing by the pupil position calculation unit according to the first embodiment. FIG. 3 is a diagram illustrating a numerical simulation of tilt position detection of the pupil position detection device according to the first embodiment, and (a) is a graph showing the estimation result of the rotation angle of the eyeball when the emmetropia state is used as the reference angle. , (b) is a graph showing the estimation result of the rotation angle of the eyeball when the pupil position is in the upper right direction from the state of emmetropia. FIG. 2 is a diagram illustrating an example of the configuration of a main part of a non-diffracted light generating section according to the first embodiment, in which (a) is a diagram illustrating the behavior of light rays due to a ring slit, and (b) is a diagram illustrating the behavior of a light beam by a ring slit; It is a figure explaining the behavior of the light beam by a ring slit. It is a figure showing an example of composition of a pupil position detection device concerning modification 1 of a 1st embodiment. It is a figure showing an example of composition of a pupil position detection device concerning modification 2 of a 1st embodiment. FIG. 6 is a diagram illustrating an example of the configuration of a main part of a non-diffracted light generating section of a pupil position detection device according to modification 3 of the first embodiment, and (a) is a diagram illustrating behavior of light rays by an axicon lens. , and (b) is a diagram explaining the behavior of light rays due to an array of axicon lenses. FIG. 6 is a diagram illustrating an example of the configuration of a main part of a non-diffracted light generation section of a pupil position detection device according to a fourth modification of the first embodiment, and (a) is a diagram illustrating behavior of a light ray by a DOE; , (b) are diagrams illustrating the behavior of light rays due to an array of DOEs. FIG. 7 is a diagram illustrating an example of the configuration of a main part of a non-diffracted light generation section of a pupil position detection device according to a fifth modification of the first embodiment, and (a) illustrates behavior of light rays by an axicon lens group. FIG. 3B is a diagram illustrating the behavior of light rays due to an array-shaped axicon lens group, and FIG. (d) is a diagram illustrating a case where the distance between the array light source and the axicon lens is narrowed. FIG. 6 is a diagram illustrating an example of the configuration of a main part of a non-diffracted light generating section of a pupil position detection device according to modification 6 of the first embodiment; FIG. (b) is a diagram explaining the behavior of light rays due to an array-shaped DOE group, (c) is a diagram explaining the behavior of light rays due to an array-shaped DOE group and an imaging plate, and (d) is a diagram explaining the behavior of light rays due to an array-shaped DOE group. FIG. 6 is a diagram illustrating a case where the distance between the light source and the DOE is narrowed. FIG. 7 is a diagram illustrating an example of the configuration of an eyeball tilt position detection device according to a second embodiment. FIG. 6 is a diagram illustrating an example of the configuration of a VCSEL according to a third embodiment, in which (a) is a diagram illustrating an example in which laser light is emitted to the active layer side, and (b) is a diagram illustrating an example in which a laser beam is emitted to the active layer side; (c) is a diagram illustrating an example in which a laser beam is emitted to the substrate side; (d) is a diagram illustrating an example in which an optical element is formed on the substrate side; FIG. . FIG. 3 is a diagram illustrating an example of the configuration of an optical element according to a third embodiment, in which (a) is a perspective view illustrating an example of the configuration in which a ring slit is formed on the light exit surface of a VCSEL, and (b) is a sectional view, (c) is a sectional view showing an example of the configuration of an array of ring slits, and (d) is a perspective view illustrating an example of the configuration in which a DOE is formed on the light exit surface of the VCSEL. (e) is a cross-sectional view, and (f) is a cross-sectional view illustrating an example of the configuration of an array-shaped DOE. FIG. 7 is a diagram illustrating an example of the configuration of a display device according to a fourth embodiment. 1 is a diagram showing the configuration of an eye tracking device described in Patent Document 1. FIG.

Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In each drawing, the same components are given the same reference numerals, and redundant explanations may be omitted.

The "eyeball tilt position" in the embodiment is the tilt or position of the pupil or cornea of the eyeball. In the embodiment, a case where an eyeball inclination position detection device is mounted on a glasses-type support will be described as an example.

In the embodiment, a device for detecting the tilt position of the right eyeball of a "person" will be described as an example, but the same applies to the left eyeball. It is also possible to provide two eyeball tilt position detection devices and apply them to the eyeballs of both eyes.

[First embodiment]
In the first embodiment, a pupil position detection device 10 will be described as an example of an eyeball tilt position detection device.

<Configuration of pupil position detection device>
FIG. 1 is a diagram showing an example of the configuration of a pupil position detection device according to this embodiment. Note that the arrows shown in the figure indicate the X direction, the Y direction, and the Z direction.

In FIG. 1, a pupil position detection device 10 includes a non-diffracted light generation section 1, a mirror 2, an optical position detection element 3, and a processing section 100. The non-diffracted light generating section 1 also includes an array light source 4, a ring slit 5, and a lens 6.

The non-diffracted light generating section 1 is provided on the spectacle frame 21 of the spectacle-shaped support 20 , and the mirror 2 and the optical position detection element 3 are fixed to the spectacle lens 22 of the spectacle-shaped support 20 .

The array light source 4 is a VCSEL (Vertical Cavity Surface Emitting Laser) that emits laser light having directivity in the positive Z direction from a plurality of positions in the XY plane. The array light source 4 is a light source in which a plurality of light emitting parts that emit laser light are arranged in a two-dimensional array in the XY plane, and the light emitting parts can be changed according to a control signal.

However, the array light source 4 is not limited to a VCSEL, and as long as it is a directional light source, the array light source 4 can be formed by arranging LDs (laser diodes) or the like in a two-dimensional array in the XY plane. may be configured. Note that the array light source 4 is an example of a "light source", and the VCSEL is an example of a "surface emitting laser".

The wavelength of the light emitted from the array light source 4 is preferably that of near-infrared light, which is non-visible light, so as not to obstruct the visibility of the "person" whose pupil position is being detected. However, the light is not limited to this, and visible light may be used.

Laser light emitted from the array light source 4 is converted by the ring slit 5 and the lens 6 into ring lights 61a and 61b, which are annular lights (hereinafter referred to as ring lights) having different wave number vectors. Then, the ring lights 61a and 61b interfere to generate undiffracted light. The configuration of this non-diffracted light generating section 1 will be described in detail separately.

The non-diffracted light emitted from the non-diffracted light generating section 1 is deflected (refracted) by the lens 6, reflected by the mirror 2 toward the eyeball 30, and is directed at a predetermined angle to the center of the pupil 31 of the eyeball 30 during emmetropia. incident at Note that the mirror 2 is an optical system provided in a direction facing the pupil 31 of the eyeball 30, and is an example of a "front eye optical system."

Here, the light deflecting means for making the undiffracted light emitted from the undiffracted light generating section 1 enter the eyeball 30 is not limited to the lens 6 and the mirror 2. Any member or combination of members may be used as long as it is possible to make the light from the array light source 4 enter the eyeball at a predetermined angle.

As a light deflection means, in addition to a convex lens, by using any one of a microlens array, a concave curved mirror, a hologram diffraction element, a prism array, or a diffraction grating, or a combination of two or more of them, the pupil position detection range can be adjusted. Effects such as enlargement of the pupil position detection device 10, miniaturization of the device, and reduction in the assembly load of the pupil position detection device 10 can be obtained.

On the other hand, the corneal surface (pupil surface) is a transparent body containing water and generally has a reflectance of about 2 to 4%. Light incident near the pupil 31 is reflected on the corneal surface of the eyeball 30, and the reflected light enters the optical position detection element 3. Here, the optical position detection element 3 is a two-dimensional PSD (Position Sensitive Detector) or the like, and is an example of a "photo detection element". Further, the corneal surface is an example of "the surface of the eyeball."

Since the incident position of the reflected light on the optical position detection element 3 changes depending on the inclination of the eyeball 30, the pupil position of the eyeball 30 can be detected by converting the detection signal from the optical position detection element 3 into coordinate information. Note that what the PSD detects is the direction of the normal vector of the reflection point, that is, the three-dimensional shape. The pupil center position is "estimated" based on the correspondence between the detected three-dimensional shape and the eyeball model.

A two-dimensional PSD detects a current value corresponding to the distance of incident light to an electrode in two orthogonal directions, detects the position of the incident light from a ratio of the current values in the two orthogonal directions, and outputs a detection signal.

Here, the two-dimensional PSD can detect the position of the incident light without depending on the light intensity of the incident light. Therefore, even if there is a difference in the amount of reflected light due to the reflection position on the eyeball 30, etc., highly sensitive position detection is possible without being affected by the difference in the amount of reflected light.

However, the optical position detection element 3 is not limited to a two-dimensional PSD. One-dimensional PSDs that can detect the position of incident light in the X direction are arranged in the Y direction, or one-dimensional PSDs that can detect the position of incident light in the Y direction are arranged in the X direction. The position within a plane may also be detected. An image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) may be used.

Since the one-dimensional PSD is cheaper than the two-dimensional PSD, etc., effects such as being able to suppress the cost of the pupil position detection device 10 can be obtained.

Furthermore, when a one-dimensional PSD or two-dimensional PSD is used as the optical position detection element 3, processing load is reduced because complex image processing is not required for position detection compared to when using an image sensor such as a CCD or CMOS. It has the effect of reducing

On the other hand, the processing section 100 includes a light emission control section 110, a pupil position calculation section 120, and an output section 130.

The light emission control unit 110 is electrically connected to the array light source 4 and transmits a control signal. The light emission control section 110 changes the light emitting section that emits light in the array light source 4 based on a control signal, and also controls the timing of light emission. The light emission control unit 110 can change the light emission timing between the plurality of light emitting units at a predetermined timing, and can change the incident angle of light onto the eyeball 30 in time series.

The pupil position calculation unit 120 is electrically connected to the optical position detection element 3 and receives a detection signal from the optical position detection element 3. The pupil position calculation unit 120 calculates the rotation angle and pupil center position of the eyeball 30 based on the detection signal, and outputs the calculation result to an external device such as a display device via the output unit 130. Here, the rotation angle and pupil center position of the eyeball 30 output by the pupil position calculation unit 120 via the output unit 130 are an example of “eyeball tilt position information”.

When the direction of the reflected light from the eyeball 30 changes due to eye movement such as rotation of the eyeball 30, the reflected light may miss the optical position detection element 3. In order to prevent this, the light emission control section 110 sequentially or selectively changes the light emitting sections that are caused to emit light by the array light source 4.

When the light emitting section changes, the light emitting position within the XY plane in the array light source 4 changes, and the incident angle of the light that enters the eyeball 30 via the lens 6 and mirror 2 changes. Thereby, the position of the light reflected by the eyeball 30 and incident on the optical position detection element 3 can be changed. Therefore, by changing the light emitting part emitted by the array light source 4 according to the eyeball movement of the eyeball 30, it is possible to prevent the reflected light from the eyeball 30 from deviating from the optical position detection element 3.

<Operation of pupil position detection device>
FIG. 2 is a diagram illustrating an example of the operation of detecting the pupil position by the pupil position detection device 10, in which (a) shows the case when the eyeball 30 is looking straight ahead, that is, when the eyeball 30 is facing forward, and (b) indicates when the eyeball 30 is rotating. FIG. 2 shows the behavior of light emitted from two light emitting parts of the array light source 4. Light 4a from one light emitting part is represented by a dotted line, and light 4b from the other light emitting part is represented by a dashed line.

In FIG. 2A, the light 4a is reflected by the eyeball 30 and is incident near the center of the optical position detection element 3. The optical position detection element 3 can detect a change in the incident position of the light 4a according to the rotation of the eyeball 30, and the pupil position calculation section 120 calculates the pupil position of the eyeball 30 based on the detection signal of the optical position detection element 3. I can do it.

On the other hand, the light 4b indicated by the dashed line does not enter the optical position detection element 3 after being reflected by the eyeball 30. Therefore, the optical position detection element 3 cannot detect the light 4b, and the pupil position calculation unit 120 cannot calculate the pupil position of the eyeball 30.

On the other hand, as shown in FIG. 2(b), when the eyeball 30 rotates significantly with respect to FIG. 2(a), the light 4a is removed from the optical position detection element 3. On the other hand, since the light 4b is incident near the center of the optical position detection element 3, the optical position detection element 3 can detect the light 4b, and the pupil position calculation unit 120 can calculate the pupil position of the eyeball 30.

In this way, the eye movement of the eyeball 30 can only be detected in a limited angular range with light from one light emitting part, whereas in this embodiment, by changing the light emitting part of the array light source 4, the eye movement of the eyeball 30 can be detected. The angle of incidence can be changed. Thereby, the detection range of the eyeball movement of the eyeball 30 and the pupil position can be expanded.

The light emitting section of the array light source 4 is changed in time series based on a control signal from the light emission control section 110 according to the eye movement of the eyeball 30. By controlling the light emitting unit according to (following) the eyeball movement of the eyeball 30, it is possible to improve the light utilization efficiency and shorten the estimation time. However, it is not necessarily necessary to "respond to eye movements." For example, the position of the light emitting part may be raster scanned at fixed time intervals independently of the eyeball movement to obtain the coarse movement position of the eyeball.

In FIG. 2, in order to simplify the explanation, only light emitted from two light emitting parts is illustrated, but more light emitting parts provided in the array light source 4 may be used. In this case, the number and position of the light emitting parts of the array light source 4 are optimized according to the size of the optical position detection element 3 and the size of the eyeball so that the pupil position of the eyeball 30 can be appropriately detected.

Next, FIG. 3 is a diagram showing an example of the hardware configuration of the processing unit 100 according to the present embodiment using functional blocks.

The processing unit 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, and an input/output I/F (Interface) 104. These are interconnected via a system bus 105.

The CPU 101 centrally controls the operation of the processing unit 100. Further, the CPU 101 executes a process of calculating the pupil position of the eyeball 30 based on the detection signal of the optical position detection element 3.

The CPU 101 executes the programs stored in the ROM 102 and the like using the RAM 103 as a work area, thereby executing the above control and processing and realizing various functions described below. Note that some or all of the functions of the CPU 101 may be realized by hardware using wired logic such as an ASIC (application specific integrated circuit) or an FPGA (field-programmable gate array).

Further, the input/output I/F 104 is an interface for connecting to external equipment such as a PC (Personal Computer) and video equipment.

FIG. 4 is a diagram showing, in functional blocks, an example of the components included in the processing unit 100 according to the present embodiment. Note that each functional block illustrated in FIG. 4 is conceptual and does not necessarily need to be physically configured as illustrated. All or part of each functional block may be configured by functionally or physically distributing and combining in arbitrary units.

As described above, the processing section 100 includes the light emission control section 110, the pupil position calculation section 120, and the output section 130. The functions of the light emission control section 110 are as described above. On the other hand, the pupil position calculation section 120 includes a detection signal reception section 121 , an eyeball rotation angle estimation section 122 , and a pupil center position calculation section 123 .

The detection signal receiving section 121 receives the detection signal output from the optical position detection element 3 and outputs it to the eyeball rotation angle estimation section 122 .

The eyeball rotation angle estimation section 122 estimates the rotation angle of the eyeball 30 based on the detection signal of the optical position detection element 3, and outputs the estimated rotation angle to the pupil center position calculation section 123.

The pupil center position calculation unit 123 calculates the center position of the pupil 31 based on the rotation angle of the eyeball 30 and outputs it to the output unit 130.

The output unit 130 outputs the calculation result by the pupil position calculation unit 120 to an external device such as a display device via the input/output I/F 104.

FIG. 5 is a flowchart illustrating an example of processing by the pupil position calculation unit 120 according to the present embodiment.

First, prior to step S51, as a preliminary preparation for calculating the pupil position, the angle at which the light emitted from the array light source 4 enters the eyeball 30 is designed, and a calculation formula for the rotation angle of the eyeball 30 is determined.

The formula for calculating the rotation angle of the eyeball 30 is a linear function or a quadratic function. However, it is not limited to this. The format of the formula does not matter as long as the rotation angle is determined from the designed light beam incident angle and the landing position of the reflected light beam on the optical position detection element 3. As a simple approximation formula, a calculation formula using a quadratic function is used in the simulation.

A model of the surface shape of the eyeball 30 is used to design the angle at which light enters the eyeball 30. As a general model of the eyeball surface shape, a schematic model of the eye has been known for a long time (see, for example, "Optical Mechanism of the Eye", Precision Instruments 27-11, 1961).

The mirror 2 (see FIGS. 1 and 2) is arranged at the focal point of the light emitted from the array light source 4. The light reflected by the mirror 2 enters the eyeball 30. The light incident on the eyeball 30 is reflected by the eyeball 30 that has been rotated by a predetermined angle, and propagates toward the optical position detection element 3 . The angle of the light incident on the eyeball 30 is determined in advance by ray tracing calculation or the like so that this propagated light is incident on the center position of the optical position detection element 3.

The incident position of the light on the optical position detection element 3 can be theoretically analyzed based on the incident angle of the light on the eyeball 30, the reflection position of the light on the eyeball 30, and the inclination of the contact surface of the eyeball 30 surface. From the solution of such theoretical analysis, an inverse calculation formula (approximate formula) for estimating the rotation angle of the eyeball 30 by polynomial approximation is determined.

The above is the advance preparation performed for calculating the pupil position prior to step S51 in FIG. The inverse calculation formula for estimating the angle of light incident on the eyeball 30 and the rotation angle of the eyeball 30 is stored in a memory such as the ROM 102 of the processing unit 100, and is controlled by the light emission control unit 110 and the pupil position calculation unit 120. Referenced in pupil position calculation.

Next, in step S51, the light emission control section 110 causes at least one of the light emitting sections of the array light source 4 to emit light at a predetermined timing according to a predetermined incident angle of light. The optical position detection element 3 detects the light emitted from the array light source 4 and reflected by the eyeball 30, and outputs a detection signal to the processing section 100. The detection signal receiving section 121 of the processing section 100 outputs the received detection signal of the optical position detection element 3 to the eyeball rotation angle estimation section 122.

Subsequently, in step S53, the eyeball rotation angle estimation unit 122 substitutes the input detection signal (position data) into the above-mentioned inverse calculation formula to calculate the eyeball rotation angle. The eyeball rotation angle estimation unit 122 outputs the calculated eyeball rotation angle to the pupil center position calculation unit 123.

Subsequently, in step S55, the pupil center position calculation unit 123 calculates the pupil center position using the model of the eyeball surface shape based on the input eyeball rotation angle, and outputs it to an external device etc. via the output unit 130. .

In this way, the pupil position detection device 10 can detect the pupil position of the eyeball 30.

Next, FIG. 6 is a diagram illustrating a numerical simulation carried out to verify the principle of the pupil position detection device 10.

In this numerical simulation, in FIG. 1, it is assumed that the mirror 2 and the optical position detection element 3 are arranged in a plane 10 mm away from the eyeball 30 in the +Z-axis direction. The reference angle (θx, θy) is the angle of the eyeball 30 when the rotation angle is changed at 5° increments at 5 points in the X direction and 3 points in the Y direction.

The horizontal axis of FIG. 6 is the amount of change in the eyeball rotation angle in the X direction, and the vertical axis is the amount of change in the eyeball rotation angle in the Y direction. This value is based on the incident angles obtained by changing the rotation angle at 5 points in the X direction and 3 points in the Y direction, both in 5° increments, as a reference (angle change amount (0, 0)).

In the numerical simulation, the exit angle at the position of the mirror 2 (reflection angle at the mirror 2) of the light reflected by the eyeball 30 and incident on the center of the optical position detection element 3 is calculated by numerical calculation for each reference angle of the eyeball 30. I asked for it. Note that the center of the optical position detection element 3 is expressed as coordinates (0, 0).

In addition, an inverse calculation formula for estimating the difference (Δθx, Δθy) between the light at each exit angle and the reference angle (θx, θy) of the eyeball 30 from the incident position (x, y) to the light position detection element 3 is calculated. was expressed by a quadratic function, and its coefficients were calculated numerically using a Taylor expansion method.

FIG. 6(a) is a graph showing the estimation result of the rotation angle of the eyeball 30 when the reference angle is (θx, θy) = (0°, 0°), that is, when the emmetropic state is used as the reference angle. . In FIG. 6(a), the grid points are the actual rotation angles of the eyeball 30, and the dots are the estimated positions. Good agreement is obtained when the rotation angle of the eyeball 30 is small. In this case, within the range of |Δθx|≦2.5°, the error is within a maximum of about 0.1°. Here, the numerical value of 2.5° is a half value of the reference angle in 5° increments, and means a condition to prevent an area where no light is detected from occurring. Furthermore, since a configuration is assumed in which the mirror 2 and the optical position detection element 3 are arranged in the X direction within a plane, the error in the Y direction is a smaller value than in the X direction.

FIG. 6(b) shows the result when the reference angle is (θx, θy)=(10°, 5°), that is, when the position of the pupil 31 is in the upper right direction from the state of emmetropia. The rotation angle of the eyeball 30 is estimated within the same error range as the result in FIG. 6(a).

The above numerical simulation results show an estimated value of the rotation angle of the eyeball 30. The rotation angle of the eyeball 30 can be defined as the angle formed by a straight line connecting the center of the eyeball 30, that is, the center of rotation and the center of the cornea, with respect to the Z axis, which is the direction of emmetropia. Therefore, the position of the pupil 31 can be calculated as a coordinate spaced from the center position of the eyeball 30 in the direction of the rotation angle of the eyeball 30 by the distance between the center position of the eyeball 30 and the center position of the cornea. Note that the distance from the center position of the eyeball 30 to the center position of the cornea is given in advance in the eyeball model.

In this way, it has been verified that the pupil position of the eyeball 30 can be calculated with sufficient accuracy by the calculation process of the pupil position calculation unit 120 shown in FIG.

The pupil position detection device 10 detects a large movement (coarse movement) of the eyeball 30 based on the changed position of the light emitting part of the array light source 4, and detects the light reflected by the eyeball 30 using the optical position detection element 3. The pupil position of the eyeball 30 may be detected over a wide range and with high precision by detecting small movements (fine movements) of the eyeball based on the incident position.

<Configuration of non-diffracted light generating section, etc.>
Next, the configuration of the non-diffracted light generating section 1 will be explained.

The array light source 4 emits a Gaussian beam of laser light. Here, the Gaussian beam refers to a light beam whose light intensity distribution in the cross section of the beam can be regarded as a Gaussian distribution.

The beam diameter w(z) of the Gaussian beam is expressed by the following equation (1).

但し、（１）式において、ｗ_０はレーザ光のビームウェスト径を表し、Ｚはビームウェストからの光軸方向の距離を表す。またＺ_Ｒは、ビームウェスト径ｗ_０とレーザ光の波長λを用いて、次の（２）式で表される変数である。

However, in equation (1), w ₀ represents the beam waist diameter of the laser beam, and Z represents the distance from the beam waist in the optical axis direction. Further, Z _R is a variable expressed by the following equation (2) using the beam waist diameter w ₀ and the wavelength λ of the laser light.

（１）式は、ガウス型ビームのレーザ光は、焦点深度が浅く、ビームウエスト（集光位置）からのレーザ光の伝搬距離に応じて、ビーム径が大きくなる特性があることを示している。

Equation (1) shows that a Gaussian beam laser beam has a shallow depth of focus, and the beam diameter increases depending on the propagation distance of the laser beam from the beam waist (focusing position). .

In FIG. 1, a Gaussian beam laser beam emitted from an array light source 4 is formed by a ring slit 5 and a lens 6, and when viewed in a cross section parallel to the light propagation direction, it becomes two parallel beams with different wave number vectors. The light is converted into ring lights 61a and 61b which are annular lights (hereinafter referred to as ring lights). Then, the ring lights 61a and 61b interfere to generate undiffracted light. In FIG. 1, the undiffracted light region 71a indicated by diagonal hatching indicates the region through which the generated undiffracted light propagates. Here, the ring light is an example of "circular light." Further, "ring-shaped light having different wave number vectors" refers to toric-shaped convergent light, which is two parallel lights when viewed in a cross section parallel to the light propagation direction, or diverging light.

Here, the undiffracted light is light that does not have the characteristic of the above-mentioned formula (1), and the beam diameter does not widen due to the diffraction phenomenon. In other words, it is light that has a deep depth of focus and a characteristic that the beam diameter does not increase depending on the propagation distance of the laser light from the beam waist (focusing position).

The characteristics of such undiffracted light can be summarized as follows [1] to [3].
[1] No diffraction.
[2] Can propagate over long distances.
[3] Light can be focused (imaged) with a resolution exceeding the diffraction limit.

Non-diffracted light includes a Bessel beam, an Airy beam, a Weber beam, a long-range nondiffracting beam (LRNB), and the like.

Furthermore, since infinite energy is required to generate a perfect undiffracted light, it is actually not possible to generate a perfect undiffracted light, but an approximated undiffracted light is generated. However, in order to simplify the explanation, the approximate undiffracted light will be referred to as undiffracted light hereinafter for convenience.

7A and 7B are diagrams illustrating an example of the configuration of the essential parts of the non-diffracted light generating section 1, in which (a) is a diagram illustrating the behavior of the light beam by the ring slit 5, and (b) is a diagram illustrating the behavior of the light beam by the ring slit 5. 5 is a diagram illustrating the behavior of light rays due to the slit 5. FIG.

In FIG. 7(a), light emitted from one light emitting part of an array light source 4 (not shown) is diffracted by a ring slit 5, deflected (refracted) by a lens 6, and is then formed into a ring light beam having a different wave number vector. is converted to Non-diffracted light is generated by the ring lights being superimposed and interfering in the non-diffracted light region 71. The beam waist diameter of the generated undiffracted light and the position and size of the undiffracted light region 71A are determined by the radius of the ring slit 5, the distance between the ring slit 5 and the lens 6, the curvature of the lens 6, and the like.

FIG. 7(b) shows a main part of the non-diffracted light generating section 1, which is constructed by arranging ring slits 5 and lenses 6 in an array. By matching the arrangement spacing of each light emitting part of the array light source 4 (not shown) with the arrangement spacing of each of the arrayed ring slits 5 and the arrayed lenses 6, an arrayed non-diffracting light region 71 is formed. Can generate light.

Returning to FIG. 1, the generated undiffracted light propagates through the undiffracted light region 71a and is reflected on the corneal surface of the eyeball 30. The reflected undiffracted light propagates through the undiffracted light region 72a and enters the optical position detection element 3. The pupil position of the eyeball 30 is detected based on the detection signal of the incident light by the optical position detection element 3.

In this embodiment, by making the undiffracted light incident on both the corneal surface of the eyeball 30 and the optical position detection element 3, the laser beam is focused on both the corneal surface of the eyeball 30 and the optical position detection element 3. Improves resolution. Thereby, the detection accuracy of the pupil position of the eyeball 30 can be improved.

Here, as a comparative example, a case will be considered in which a Gaussian beam of laser light is made to enter the eyeball 30. If the distance (optical path length) from the mirror 2 to the eyeball 30 changes due to the eyeglass frame 21 being shifted, etc., the incident light will not be condensed on the corneal surface (beam waist state), and abnormalities will occur on the corneal surface. Reflection and scattering may occur, and the reflected light on the corneal surface may not properly enter the optical position detection element 3.

Incidentally, abnormal reflection refers to cases where the light incident on the optical position detection element 3 after being reflected on the corneal surface becomes diverging light that spreads widely, and abnormal scattering refers to cases where the light incident on the corneal surface becomes divergent light. This is the case when the light spreads widely and is scattered at the edge of the cornea.

Similarly, even if the distance from the eyeball 30 to the optical position detecting element 3 changes due to displacement of the eyeglass frame 21, etc., the light incident on the optical position detecting element 3 will be at the beam waist on the optical position detecting element 3. In some cases, the position of the incident light cannot be appropriately detected by the optical position detection element 3.

These factors cause a decrease in the detection accuracy of the pupil position of the eyeball 30.

In contrast, in the present embodiment, the beam diameter of the undiffracted light incident on the eyeball 30 does not increase depending on the propagation distance of the laser light. Therefore, even if the distance from the mirror 2 to the eyeball 30 changes due to displacement of the eyeglass frame 21, etc., the laser beam can be incident on the corneal surface of the eyeball 30 in the state of the beam waist, and the incident light can be directed to the corneal surface of the eyeball 30. It can be properly reflected on the corneal surface.

Further, the laser light that is made incident on the optical position detection element 3 is also non-diffracted light. Therefore, even if the distance between the eyeball 30 and the pupil position detection device 10 changes, the laser beam can be made to enter the optical position detection element 3 in the state of the beam waist, and the position of the incident light can be adjusted appropriately by the optical position detection element 3. can be detected.

In this way, in this embodiment, by making the laser beam enter the corneal surface of the eyeball 30 and the optical position detection element 3 in a beam waist state using non-diffracted light, the reflected light from the corneal surface of the eyeball 30 is can be appropriately detected by the optical position detection element 3. In addition, the robustness of detecting the position of the pupil of the eye against vibrations and external shocks can be improved.

Note that an automatic position adjustment means may be added to the configuration of the non-diffracted light generating section 1 to provide an automatic focus adjustment function. The automatic focus adjustment function allows the propagation angle of ring lights with different wave number vectors to be changed, so the generation position of undiffracted light can be adjusted. Furthermore, the robustness of pupil position detection against individual differences such as misalignment of the eyeglass frame 21 and the shape of the user's face or the shape of the eyeballs 30 can be further improved.

(Modification 1)
FIG. 8 is a diagram showing an example of the configuration of the pupil position detection device 11 according to Modification 1 of the present embodiment. The pupil position detection device 11 generates undiffracted light only in a spatial range between the mirror 2 and the corneal surface of the eyeball 30. Here, the spatial range between the mirror 2 and the corneal surface of the eyeball 30 is defined as a boundary surface that passes along the normal line of the corneal surface of the eyeball and the incident light and is perpendicular to the ray propagation plane of the incident light. It is defined as the area where light rays travel toward the cornea of the eye. In FIG. 8, the spatial extent between mirror 2 and the corneal surface of eyeball 30 is shown as undiffracted light region 72. In FIG.

In the pupil position detection device 11, undiffracted light generated in a limited spatial range is made to enter the corneal surface of the eyeball 30. Thereby, the focusing resolution of the laser beam on the corneal surface of the eyeball 30 can be improved, and the detection accuracy of the pupil position of the eyeball 30 can be improved. Furthermore, the robustness of pupil position detection against displacement of the eyeglass frame 21 can be improved.

(Modification 2)
FIG. 9 is a diagram showing an example of the configuration of a pupil position detection device 12 according to a second modification of the present embodiment. The pupil position detection device 12 generates undiffracted light only in a spatial range between the corneal surface of the eyeball 30 and the optical position detection element 3 . In FIG. 9, a undiffracted light region 73 indicates a region in which undiffracted light propagates.

Here, in the pupil position detection devices 10 and 11, even if light with uniform wave number vectors is incident on the corneal surface of the eyeball 30, the reflected light becomes diverging light that spreads toward the optical position detection element 3 due to the curvature of the corneal surface. In some cases, the intensity of the reflected undiffracted light is attenuated, or the wave number vectors are not aligned after reflection, and the undiffracted light is not generated.

Therefore, in the pupil position detection device 12, the curvature of the corneal surface is known in advance by measuring the curvature, and convergent light whose wave number vectors are aligned after being reflected on the corneal surface is made to enter the eyeball 30. Thereby, the laser light whose wave number vector is aligned due to reflection on the corneal surface can be interfered with to generate undiffracted light, which can be propagated through the undiffracted light region 73 and made to enter the optical position detection element 3.

By making the light incident on the optical position detection element 3 non-diffracted, the light collection resolution can be improved as described above, and the detection accuracy of the pupil position of the eyeball can be improved. Furthermore, the robustness against misalignment of the eyeglass frame 21 can be improved.

(Modification 3)
FIG. 10 is a diagram illustrating an example of the configuration of the main part of the non-diffracted light generating section 1a of the pupil position detection device 13 according to the third modification of the present embodiment, and (a) shows the configuration of the main part of the non-diffracted light generating section 1a. FIG. 3B is a diagram illustrating the behavior of light rays caused by the array-shaped axicon lens 5a.

Note that an axicon lens is a lens having a conical surface shape, and the axicon lens 5a is an example of a "conical lens."

In FIG. 10(a), parallel light emitted from one light emitting part of the array light source 4 (not shown) is deflected by an axicon lens 5a and converted into light having a different wave number vector. These light beams are superposed and interfered in the non-diffracted light region 71, thereby generating non-diffracted light such as a Bessel beam. The beam waist diameter of the generated undiffracted light and the position and size of the undiffracted light region 71 are determined by the curvature, conic constant, etc. of the axicon lens 5a.

FIG. 7B shows a non-diffracted light generating section 1a configured by arranging an array of axicon lenses 5a in an array. By matching the arrangement interval of each light emitting part of the array light source 4 (not shown) with the arrangement interval of the arrayed axicon lens 5a, an array of undiffracted light can be generated.

(Modification 4)
FIG. 11 is a diagram illustrating an example of the configuration of the main part of the non-diffracted light generating section 1b of the pupil position detection device 14 according to the fourth modification of the present embodiment, and (a) is a diagram illustrating an example of the configuration of the main part of the non-diffractive light generating section 1b of the pupil position detection device 14 according to the fourth modification of the present embodiment. (b) is a diagram illustrating the behavior of light rays due to the DOE 5b in the form of an array. Note that the DOE is an optical element in which a periodic structure is formed on a flat plate, and has a function of deflecting (refracting) passing light rays. Further, the DOE 5b is an example of a "diffractive optical element."

In FIG. 11A, parallel light emitted from one light emitting part of the array light source 4 (not shown) is deflected by the DOE 5b and converted into light having a different wave number vector. These light beams are superposed and interfered in the non-diffracted light region 71, thereby generating non-diffracted light such as a Bessel beam. The beam waist diameter of the generated undiffracted light and the position and size of the undiffracted light region 71 are determined by the interval of the periodic structure of the DOE 5b, etc.

FIG. 11(b) shows a non-diffracted light generating section 1b configured by arranging DOEs 5b in an array. By matching the arrangement interval of each light emitting part of the array light source 4 (not shown) with the arrangement interval of the DOE 5b, an array of undiffracted light can be generated.

(Modification 5)
FIG. 12 is a diagram illustrating an example of the configuration of the main part of the non-diffracted light generating section 1c of the pupil position detection device 15 according to modification 5 of the present embodiment, and (a) shows a plurality of axes in the optical axis direction. This is a diagram illustrating the behavior of light rays due to the axicon lens group 5c in which con lenses are arranged, and (b) is a diagram illustrating the behavior of light rays due to the axicon lens group 5c arranged in an array. Further, (c) is a diagram explaining the behavior of light rays due to the arrayed axicon lens 5ca and the imaging plate 5cc, and (d) is a diagram explaining the case where the distance between the array light source 4 and the axicon lens 5ca is narrowed. It is.

In FIG. 12A, the axicon lens group 5c includes a concave axicon lens 5ca having a concave surface and a biconvex axicon lens 5cb having two convex surfaces. Here, the axicon lens group 5c is an example of a "conical lens group."

Parallel light emitted from one light emitting part of the array light source 4 (not shown) is deflected by the axicon lens group 5c and converted into light having a different wave number vector. These light beams are superposed and interfered in the non-diffracted light region 71, thereby generating non-diffracted light such as a Bessel beam.

In the axicon lens group 5c, the concave axicon lens 5ca acts to spread (diverge) the incident light, and the biconvex axicon lens 5cb acts to converge the incident light.

The beam waist diameter of the generated undiffracted light and the position and size of the undiffracted light region 71 are determined by the curvatures and conic constants of the concave axicon lens 5ca and the biconvex axicon lens 5cb.

FIG. 12(b) shows a non-diffracted light generating section 1c configured by arranging axicon lens groups 5c in an array. By matching the arrangement interval of each light emitting part of the array light source 4 (not shown) with the arrangement interval of the arrayed axicon lens group 5c, an array of undiffracted light can be generated.

FIG. 12(c) shows a case where an imaging plate 5cc is provided in place of the biconvex axicon lens 5cb. Here, the imaging plate 5cc includes two transparent flat plates on which strip-shaped micromirrors are arranged in an array, and is constructed by pasting the two transparent plates together so that the longitudinal directions of the strip-shaped micromirrors intersect. It is an optical element with

The imaging plate 5cc can form an image on the side opposite to the light source by reflecting the incident light on one micromirror and then reflecting it again on the other micromirror.

Further, since the orthogonal micromirrors are distributed in a two-dimensional array within the imaging plate 5cc, the same imaging performance can be obtained no matter which surface of the imaging plate 5cc is used. By utilizing such characteristics, as shown in FIG. 12(d), the array light source 4 (not shown) and the array-shaped The interval between the axicon lenses 5ca can be freely narrowed.

(Modification 6)
FIG. 13 is a diagram illustrating an example of the configuration of the main part of the non-diffracted light generating section 1d of the pupil position detection device 16 according to modification 6 of the present embodiment, and (a) shows a plurality of DOEs in the optical axis direction. (b) is a diagram illustrating the behavior of light rays due to the DOE group 5d arranged in an array. Moreover, (c) is a figure explaining the behavior of the light beam by the array-shaped DOE5da and the imaging plate 5dc, and (d) is a figure explaining the case where the space|interval between the array light source 4 and DOE5da is narrowed.

In FIG. 13A, the DOE group 5d includes a DOE 5da that acts as a concave lens and a DOE 5db that acts as a biconvex lens. Here, the DOE group 5d is an example of a "diffractive optical element group."

Parallel light emitted from one light emitting part of the array light source 4 (not shown) is deflected by the DOE group 5d and converted into light having a different wave number vector. These light beams are superposed and interfered in the non-diffracted light region 71, thereby generating non-diffracted light such as a Bessel beam.

Note that among the DOE group 5d, the DOE 5da acts to spread (diverge) the incident light, and the DOE 5db acts to converge the incident light.

The beam waist diameter of the generated undiffracted light and the position and size of the undiffracted light region 71 are determined by the curvature and conic constant of the DOEs 5da and 5db.

FIG. 13(b) shows a non-diffracted light generating section 1d configured by arranging DOE groups 5d in an array. By matching the arrangement interval of each light emitting part of the array light source 4 (not shown) with the arrangement interval of the arrayed axicon lens group 5c, an array of undiffracted light can be generated.

FIG. 13(c) shows a case where an imaging plate 5dc is provided in place of the DOE 5db. The imaging plate 5dc can form an image on the side opposite to the light source by reflecting the incident light on one micromirror and then reflecting it again on the other micromirror.

Further, since the orthogonal micromirrors are distributed in a two-dimensional array within the imaging plate 5cc, the same imaging performance can be obtained no matter which surface of the imaging plate 5dc is used. By utilizing such characteristics, as shown in FIG. 13(d), the array light source 4 (not shown) and the array-shaped The interval between DOE5da can be freely narrowed.

[Second embodiment]
Next, an eyeball tilt position detection device 17 according to a second embodiment will be described with reference to FIG. 14. Note that descriptions of the same components as those of the previously described embodiments will be omitted.

FIG. 14 is a diagram showing an example of the configuration of the eyeball tilt position detection device 17 according to the present embodiment. The eyeball inclination position detection device 17 includes the non-diffracted light generating section 1 and the optical position detection element 3 as one body, and is provided on the eyeglass frame 21 of the eyeglass type support 20 .

The non-diffracted light emitted from the non-diffracted light generating section 1 is deflected (refracted) by the lens 6 and enters the eyeball 30. The incident light is reflected by the eyeball 30, and the reflected light enters the optical position detection element 3.

Since the position at which the reflected light enters the optical position detection element 3 changes depending on the inclination of the eyeball 30, the pupil position of the eyeball 30 can be detected by converting the detection signal from the optical position detection element 3 into coordinate information. .

In this way, by integrating the non-diffracted light generating section 1 and the optical position detecting element 3, the configuration of the eyeball tilt position detecting device can be simplified.

Note that other effects are the same as those described in the first embodiment.

[Third embodiment]
Next, an eyeball tilt position detection device 18 according to a third embodiment will be described with reference to FIGS. 15 and 16. Note that descriptions of the same components as those of the previously described embodiments will be omitted.

Since VCSELs are manufactured using semiconductor manufacturing technology, optical elements having various functions can be laminated onto the VCSELs. Therefore, in this embodiment, a VCSEL equipped with an optical element for generating non-diffracted light is used as the light source of the eyeball tilt position detection device, and the non-diffracted light generating section is made smaller and thinner, and alignment accuracy is improved. Efforts are being made to increase the amount of light.

FIG. 15 is a diagram illustrating an example of the configuration of a VCSEL equipped with an optical element for generating non-diffracted light, and (a) shows the VCSEL emitting laser light toward the active layer (surface) side when viewed from the substrate. It is a figure explaining an example, and (b) is a figure explaining the example in which the optical element was formed in the film formed into the active layer side. Further, (c) is a diagram illustrating an example in which laser light is emitted from the substrate (back side) side when viewed from the active layer, and (d) is a diagram illustrating an example in which an optical element is formed on a film formed on the back side of the substrate. This is a diagram.

In FIG. 15A, in the VCSEL 4a, on an n-type semiconductor substrate 151, a first DBR (Distributed Bragg Reflector) layer 152, an n-type spacer layer 153, an active layer 154, a p-type spacer layer 155, and A second DBR layer 156 is sequentially formed. Here, the first DBR layer 152 is a layer with high reflectance, and the second DBR layer 156 is a layer with low reflectance.

In the VCSEL 4a, light emitted from the active layer 154 due to the supply of a driving current travels back and forth between the first DBR layer 152 and the second DBR layer 156, causing stimulated emission in the active layer 154 and causing laser oscillation. The light is emitted from the light exit surface.

At this time, by forming an optical element on the upper light exit surface, the beam profile and mode of the laser beam can be arbitrarily controlled. Such an optical element is formed by applying photolithographic patterning to the formation of a p-type contact electrode. Alternatively, as in the VCSEL 4b shown in FIG. 15(b), an optical element may be formed by subjecting a light shielding film 157 newly formed on the second DBR layer to photolithography patterning.

On the other hand, in FIG. 15(c), in the VCSEL 4c, the first DBR layer 152 is a layer with low reflectance, the second DBR layer 156 is a layer with high reflectance, and the laser beam is emitted from the bottom of the n-type semiconductor substrate 151. is used as the light exit surface.

At this time, by forming an optical element on the lower light exit surface of the n-type semiconductor substrate 151, the beam profile and mode of the laser beam can be controlled as desired. Such an optical element is formed by applying photolithographic patterning to the formation of an n-type contact electrode on the back surface. Alternatively, as in a VCSEL 4d shown in FIG. 15(d), an optical element may be formed by subjecting a light-shielding film 158 newly formed on the back surface side of the n-type semiconductor substrate 151 to photolithography patterning.

Next, FIG. 16 is a diagram illustrating an example of the configuration of an optical element mounted on a VCSEL to generate undiffracted light, and (a) shows a configuration in which a ring slit 5 is formed on the light exit surface of the VCSEL 4. It is a perspective view explaining an example, (b) is a sectional view, and (c) is a sectional view explaining an example of the configuration of the ring slits 5 in an array. Further, (d) is a perspective view illustrating an example of a configuration in which DOEs 5b are formed on the light exit surface of the VCSEL 4, (e) is a sectional view, and (f) is an example of a configuration of DOEs 5b in an array. FIG.

With the configurations shown in FIGS. 16(a) to 16(c), the amount of light can be increased compared to the case where the array light source 4 and the ring slit 5 are configured separately. Alignment accuracy can be improved.

Furthermore, with the configurations shown in FIGS. 16(d) to (f), it is possible to increase the amount of light compared to the case where the array light source 4 and the DOE 5b are configured separately. Alignment accuracy can be improved.

As explained above, by using a VCSEL equipped with an optical element for generating non-diffracted light, an eyeball tilt position detection device including a non-diffracted light generating section and a non-diffracted light generating section can be miniaturized and/or Or it can be made thinner. Furthermore, it is possible to improve the alignment accuracy between the array light source and the optical element and/or to increase the amount of light, thereby improving the detection accuracy of the eyeball tilt position detection device.

[Fourth embodiment]
Next, a display device according to a fourth embodiment will be described with reference to FIG. 17. Note that descriptions of the same components as those of the previously described embodiments will be omitted.

In this embodiment, a head mount display (HMD), which is a wearable terminal, will be described as an example of a display device. Further, an example will be described in which a pupil position detection device 10, which is an example of an eyeball tilt position detection device, is applied to a head mounted display.

FIG. 17 is a diagram showing an example of the configuration of the display device 50 according to this embodiment.

The display device 50 includes an RGB (Red, Green, Blue) laser light source 51, a scanning mirror 52, a mirror 53, a half mirror 54, an image generation section 55, and a pupil position detection device 10.

The RGB laser light source 51 temporally modulates and outputs laser light of three colors of RGB. The scanning mirror 52 is a MEMS mirror or the like that two-dimensionally scans the light from the RGB laser light source 51. However, the mirror is not limited to this, and any mirror that has a reflective surface that scans light, such as a polygon mirror or a galvano mirror, may be used. MEMS mirrors are advantageous in terms of size and weight reduction. Note that the MEMS mirror may be driven by any of electrostatic, piezoelectric, and electromagnetic methods.

Mirror 53 reflects the scanning light from scanning mirror 52 toward half mirror 54 . The half mirror 54 transmits a portion of the incident light and reflects a portion toward the eyeball 30 . The half mirror 54 has a concave curved shape, converges the reflected light near the pupil 31 of the eyeball 30, and forms an image at the position of the retina 32. As a result, an image formed by the scanning light is projected onto the retina 32. Light 51a indicated by a broken line in the figure represents light that forms an image on the retina 32. Note that in the half mirror 54, the amount of reflected light and transmitted light does not necessarily have to be one to one.

The pupil position detection device 10 detects the position of the pupil 31 according to eye movement, and transmits a feedback signal indicating the position of the pupil 31 to the image generation unit 55.

The image generation unit 55 has a deflection angle control function of the scanning mirror 52 and a light emission control function of the RGB laser light source 51. The image generation unit 55 also receives a feedback signal indicating the position of the pupil 31 from the pupil position detection device 10.

The image generation unit 55 controls the deflection angle of the scanning mirror 52 and the light emission of the RGB laser light source 51 according to the position of the pupil 31, and rewrites the projection angle of the image or the image content. Thereby, it is possible to form an image on the retina 32 that follows (eye tracking) the change in the position of the pupil 31 due to eyeball movement.

The display device 50 as a head-mounted display is not only attached directly to a person's head, but also indirectly attached to a person's head via a member such as a fixing part. Good too. Alternatively, a binocular display device may be used in which a pair of display devices 50 are provided for left and right eyes.

Although examples of embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and various modifications may be made within the scope of the gist of the present invention as described in the claims. It is possible to transform and change.

For example, it can be adopted in an optometry device that has a function of detecting the tilt of the eyeball and the position of the pupil (cornea). An optometry device refers to a device that can perform various tests such as a visual acuity test, an eye refractive power test, an intraocular pressure test, and an axial length test. An optometry device is a device that can perform eye examinations without contacting the eyeballs, and includes a support part that supports the subject's face, an optometry window, and a display that keeps the subject's eyeball direction (direction of line of sight) constant during the eye exam. It has a display section, a control section, and a measurement section. In order to improve the measurement accuracy of the measurement unit, the patient is required to stare at a single point without moving their eyes (line of sight), and the test subject fixes his or her face on the support and stares at the object displayed on the display through the optometry window. . At this time, when detecting the tilted position of the eyeball, the eyeball tilted position detection device according to this embodiment can be used. The eyeball tilt position detection device is placed on the side of the measurement unit so as not to interfere with the measurement. The eyeball tilt position (line of sight) information obtained by the eyeball tilt position detection device can be fed back to the control unit, and measurements can be made in accordance with the eyeball tilt position information.

Further, information on the pupil position detected by the pupil position detection device 10 can also be used for eye tracking in an input device of an electronic device. For example, the output of the pupil position detection device 10 shown in FIG. 1 may be used for eye tracking as input information to an electronic device. This makes it possible to realize eye tracking that is robust against head position deviations and the like.

Here, the device described in Patent Document 1 will be compared with the pupil position detection devices 10 to 16 and the eyeball tilt position detection devices 17 to 18 according to the embodiments. FIG. 18 is a diagram showing the configuration of an eye tracking device described in Patent Document 1.

In the device described in Patent Document 1, a laser light source is used, the laser light is scanned by a MEMS mirror, and the incident angle of the light to the eyeball 30 is changed. In contrast, in the embodiment, an array light source 4 having a plurality of light emitting sections is used as a light source, and by changing the light emitting sections of the array light source 4, the incident angle of light to the eyeball 30 is changed. Furthermore, in the embodiment, by using a light deflecting means (lens, plane mirror, microlens array, concave curved mirror, hologram diffraction element, prism array, diffraction grating, etc.) in conjunction with the array light source 4, the range of change of the incident angle can be changed. is expanding. In the embodiment, since the angle of incidence of light on the eyeball 30 is changed without using a movable part in this way, the structure is more resistant to vibrations, external shocks, etc. compared to a configuration including a movable part.

In the device described in Patent Document 1, the reflected light intensity of the light irradiated to the cornea is detected by a photodetector, whereas in the embodiment, an optical position detection element 3 such as a two-dimensional PSD is used to detect the intensity of the reflected light by the eyeball 30. Detect the position of reflected light. Since the PSD can detect incident light without depending on the light intensity, even if there is a difference in the amount of reflected light due to the position of light reflection on the eyeball 30, etc., the PSD has high sensitivity without being affected by the difference in the amount of reflected light. It is possible to detect the position of As a result, the tilted position of the eyeball can be detected with high precision.

In the embodiment, a light emission control section 110 is provided, and the light emission control section 110 shifts the positions of the light emitting sections of the array light source 4 and the light emission timings between the light emitting sections and lights them up individually. This allows coarse movements of the eyeball 30 to be captured so that the light reflected from the eyeball 30 is contained in the optical position detection element 3, and fine movements of the eyeball 30 can be captured by position detection by the optical position detection element 3. can.

In the device described in Patent Document 1, the eyeball position is estimated from two peak intensities (reflection positions on the cornea at two points) on the time axis of light reflected by the eyeball. In the embodiment, the eyeball position is estimated based on the reflection position of one point on the eyeball, such as the cornea. Therefore, the array light source 4 and the optical position detection element 3 do not necessarily have to be in symmetrical positions. In the embodiment, the optical position detection element 3 may not be placed near the regular reflection (specular reflection) angle of the eyeball 30, but may be placed on the same side as the array light source 4.

1 Non-diffracted light generating section 2 Mirror (an example of a front optical system)
3 Optical position detection element (an example of a photodetection element)
4 Array light source (an example of a light source)
5 Ring slit 6 Lenses 10 to 16 Pupil position detection devices 17 to 18 Eyeball tilt position detection device 20 Spectacle-type support 21 Spectacle frame 22 Spectacle lens 30 Eyeball 31 Pupil 32 Retina 50 Display device 51 RGB laser light source 52 Scanning mirror 53 Mirror 54 Half mirror 55 Image generation section 100 Processing section 101 CPU
102 ROM
103 RAM
104 Input/output I/F
105 System bus 110 Light emission control section 120 Pupil position calculation section 121 Detection signal reception section 122 Eyeball rotation angle estimation section 123 Pupil center position calculation section 130 Output section 151 N-type semiconductor substrate 152 First DBR layer 153 N-type spacer layer 154 Active layer 155 P-type spacer layer 156 Second DBR layer 157, 158 Light shielding film

US2016/0166146

IEEE 30th International Conference on Micro Electro Mechanical Systems (MEMS), Las Vegas, 2017, pp. 304-307

Claims (11)

A surface emitting laser for a pupil or cornea position detection device that oscillates light using an active layer and a reflecting mirror and emits light from a light exit surface via an optical element,
A surface emitting laser for a pupil or cornea position detection device , wherein the light emitted from the optical element has an annular shape when viewed from a direction perpendicular to the light exit surface. A surface emitting laser for a pupil or cornea position detection device that oscillates light using an active layer and a reflecting mirror and emits light from a light exit surface via an optical element,
The optical element includes a light shielding part that covers a first region of the light exit surface, and emits light from a second region outside the first region. laser. The surface emitting laser for a pupil or cornea position detection device according to claim 1 or 2, wherein the optical element is formed on the light exit surface. comprising an electrode pair for supplying current to the active layer,
The surface emitting laser for a pupil or corneal position detection device according to any one of claims 1 to 3, wherein one of the electrode pairs is formed on the same surface as the optical element. The position of the pupil or cornea according to any one of claims 1 to 4, wherein the light exit surface is located on the substrate side on which the surface emitting laser for the pupil or cornea position detection device is formed. Surface emitting laser for detection equipment . 5. The light emitting surface is located on the opposite side of the active layer to the substrate on which the surface emitting laser for the pupil or corneal position detection device is formed. The surface emitting laser for a pupil or corneal position detection device as described above. The optical element is a diffractive optical element,
The surface emitting device for detecting the position of a pupil or cornea according to any one of claims 1 to 6, wherein the light diffracted by the diffractive optical element overlaps in a direction perpendicular to the light exit surface. laser. The pupil or cornea according to claim 7, wherein the light diffracted by the diffractive optical element is superimposed in a direction perpendicular to the light exit surface to generate undiffracted light. Surface emitting laser for position detection equipment . A surface emitting laser for a pupil or corneal position detection device according to any one of claims 1 to 6;
having a lens;
the optical element is a ring slit;
The light source device, wherein the lens superimposes the light passing through the ring slit in a direction perpendicular to the light exit surface. The light source device according to claim 9, wherein the light that has passed through the lens is superimposed in a direction perpendicular to the light exit surface to generate undiffracted light. An eyeball tilt position detecting device comprising: the surface emitting laser for a pupil or corneal position detecting device according to any one of claims 1 to 8; or the light source device according to claim 9 or 10.

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