Eyeball inclination position detection device

Abstract

To provide an eyeball inclination position detection device that is resistant to vibration and external impact.SOLUTION: An eyeball inclination position detection device includes: a light source array including a plurality of light-emission parts for emitting light having directivity; and a light position detection element for detecting a light position of reflected light from the eyeball of the light.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an eyeball tilt position detection device, a display device, and an eye examination device. [Background technology]

[0002] 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. Considering that people who use AR technology obtain most of their cognitive information through their eyesight, glasses-type image display devices that can be used in the working environment have been developed.

[0003] As such a glasses-type image display device, a glasses-type image display device using a retinal imaging method that uses a laser to directly image a person's retina is known. With the retinal imaging method, a focus-free image is superimposed on visual information, so that digital information can be displayed on the retina with the person's viewpoint focused on the outside world, allowing the person to recognize it.

[0004] However, in glasses-type image display devices that use a laser to draw on the retina, due to limitations in the size of the cornea and pupil, in behavioral (work) environments involving eye movement, laser vignetting can occur around the outer periphery of the cornea or pupil, making it impossible to draw the specified image in the specified position.

[0005] To address these issues, an eye tracking technology has been disclosed that includes a MEMS (Micro Electro Mechanical Systems) mirror that scans a laser over the eyeball, a photodetector for detecting the intensity of reflected light, and an electronic circuit that estimates the position of the cornea on the eyeball from the detected intensity in order to detect the position of the cornea and provide feedback to the image drawing position, etc. (see, for example, Patent Document 1 and Non-Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technologies of Patent Document 1 and Non-Patent Document 1 have movable structures such as MEMS mirrors, and therefore the detection accuracy of the eyeball tilt position, such as the cornea position, can sometimes decrease due to vibrations, external impacts, etc.

[0007] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide an eyeball tilt position detection device that is resistant to vibration and external shock. [Means for solving the problem]

[0008] According to one aspect of the disclosed technology, there is provided a device for detecting the tilt position of an eyeball, characterized in that it comprises a light source array having a plurality of light-emitting units that emit directional light, and an optical position detection element that detects the optical position of the light reflected from the eyeball. Effect of the Invention

[0009] According to an embodiment of the present invention, it is possible to provide an eyeball tilt position detection device that is resistant to vibrations and external shocks. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an example of the configuration of a pupil position detection device according to a first embodiment. [Diagram 2] 3A to 3C are diagrams illustrating an example of an operation of pupil position detection by the pupil position detection device of the first embodiment. [Diagram 3] 2 is a functional block diagram illustrating an example of a hardware configuration of a processing unit according to the first embodiment. FIG. [Figure 4] 2 is a functional block diagram illustrating an example of components included in a processing unit of the first embodiment. FIG. [Diagram 5] 5 is a flowchart showing an example of processing by a pupil position calculation unit in the first embodiment. [Figure 6] 5A to 5C are diagrams illustrating a numerical simulation carried out for verifying the principle of pupil position detection in the pupil position detection device of the first embodiment. [Figure 7]FIG. 11 is a diagram illustrating an example of the configuration of a pupil position detection device according to a second embodiment. [Figure 8] FIG. 13 is a diagram illustrating an example of an optical deflection means according to the third embodiment. [Figure 9] 13A and 13B are diagrams showing an example of a configuration in which a light distribution module according to a third embodiment is arranged on a glasses-type support body. [Figure 10] FIG. 13 is a diagram illustrating an example of a configuration of a display device according to a fourth embodiment. [Figure 11] FIG. 1 is a diagram showing a configuration of an eye-tracking device described in Patent Document 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and duplicated explanations may be omitted.

[0012] In the embodiment, the "eyeball tilt position" refers to the position of the pupil or cornea of ​​the eyeball, etc. In the following, an example will be described in which the "eyeball tilt position" refers to the position of the pupil, and the "eyeball tilt position detection device" refers to the "pupil position detection device." In the following, the "eyeball tilt position detection device" will simply be referred to as the "pupil position detection device." In addition, an example will be described in which the "pupil position detection device" is mounted on a glasses-type support.

[0013] In the embodiment, the pupil position detection device for the right eye of a "person" is described as an example, but the same applies to the left eye. Also, two pupil position detection devices may be provided and applied to both eyeballs.

[0014] [First embodiment] 1 is a diagram showing an example of the configuration of a pupil position detection device according to this embodiment, in which arrows indicate the X, Y, and Z directions.

[0015] 1, pupil position detection device 10 has a light source array 1, a lens 2, a plane mirror 3, an optical position detection element 4, and a processing unit 100. The light source array 1 and the lens 2 are provided in a spectacle frame 21 of a spectacle-type support body 20, and the plane mirror 3 and the optical position detection element 4 are provided in a spectacle lens 22 of the spectacle-type support body 20. The processing unit 100 has a light emission control unit 110 and a pupil position calculation unit 120.

[0016] The light source array 1 has a plurality of light emitting sections arranged two-dimensionally within a plane. Note that the term "a plurality of light emitting sections" is synonymous with "a plurality of light emitting points" or "a plurality of light emitting elements."

[0017] Each light emitting unit emits directional laser light upward in the figure. The light source array 1 is, for example, a VCSEL (Vertical Cavity Surface Emitting Laser) with the emission direction facing upward in the figure. However, the light source array 1 is not limited to this, and for example, the light source array 1 may be configured by arranging a plurality of LDs (Laser Diodes) that emit directional laser light two-dimensionally in a plane.

[0018] The wavelength of the light emitted from the light source array 1 is preferably a near-infrared wavelength, which is invisible light, so as not to impede the visibility of the "person" whose pupil position is to be detected. However, the wavelength is not limited to this and may be visible light.

[0019] The lens 2 deflects the light emitted from the light source array 1 in a predetermined direction. The lens 2 is, for example, a convex lens, and refracts the light passing through it, thereby deflecting the passing light in a predetermined direction. The light source array 1 and the lens 2 are fixed to the same substrate 5a and integrated to form a light distribution module 5. The light distribution module 5 is fixed to a stable, stationary support such as a spectacle frame 21 provided on the spectacle-type support 20.

[0020] The light deflected by the lens 2 is reflected by the plane mirror 3 towards the eyeball 30. The plane mirror 3 is fixed to the eyeglass lens 22 of the eyeglass-type support body 20. Due to deflection by the lens 2 and reflection by the plane mirror 3, the light from the light source array 1 is incident at a predetermined angle on the center of the pupil 31 of the eyeball 30 when viewing normally. The lens 2 and the plane mirror 3 have the function of deflecting the light from the light source array 1 to make it incident on the eyeball 30. The lens 2 and the plane mirror 3 are an example of "light deflection means for making light incident on the eyeball at a predetermined angle".

[0021] The light deflection means is not limited to the lens 2 and the plane mirror 3. Any member or combination of any members may be used as long as the light from the light source array 1 can be incident on the eyeball at a predetermined angle. However, by using, as the light deflection means, any one or a combination of two or more of the following in addition to the above-mentioned convex lens: a microlens array, a concave curved mirror, a hologram diffraction element, a prism array, or a diffraction grating, it is possible to obtain effects such as an expansion of the pupil detection range, a miniaturization of the device, and a reduction in the assembly load of the pupil position detection device 10. Other examples of such light deflection means will be described in detail in the third embodiment.

[0022] The pupil surface (corneal surface) is a transparent body that contains water and generally has a reflectance of approximately 2 to 4%. Light that enters the vicinity of the pupil 31 is reflected at a reflection point P on the pupil surface (corneal surface) of the eyeball 30, and the reflected light enters a position sensitive detector 4. The position sensitive detector 4 is, for example, a two-dimensional PSD (Position Sensitive Detector).

[0023] The PSD detects the direction of the normal vector of the reflection point, i.e., the three-dimensional shape. The position of the pupil center is "estimated" based on the correspondence between the detected three-dimensional shape and the eyeball model.

[0024] The two-dimensional PSD detects current values ​​according to the distance to the electrodes in two orthogonal directions on the light receiving surface from the position of the incident light on the light receiving surface, and calculates and outputs the position of the incident light from the ratio of the current values ​​in the two directions. 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 a difference occurs in the amount of reflected light due to the reflection position on the eyeball 30, the two-dimensional PSD can perform highly sensitive position detection without being affected by the difference in the amount of reflected light. In addition, compared to the case where an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) is used as the light position detection element 4, there is an effect of reducing the processing load because complex image processing is not required for position detection.

[0025] However, the light position detecting element 4 is not limited to a two-dimensional PSD. One-dimensional PSDs capable of detecting the position of incident light in the X direction may be arranged in the Y direction, or one-dimensional PSDs capable of detecting the position of incident light in the Y direction may be arranged in the X direction to detect the position of incident light in the XY plane. In this case, one-dimensional PSDs are less expensive than two-dimensional PSDs, etc., and thus an effect such as reducing the cost of the pupil position detection device 10 can be obtained.

[0026] Alternatively, an imaging element such as a CCD or CMOS may be used as the light position detection element 4, and the position of light may be detected or estimated by image processing based on the spatial intensity distribution of light incident on the imaging surface.

[0027] The position of light incident on the light receiving surface of the position-sensitive detector 4 is an example of the "light position of light reflected from the eyeball".

[0028] The light emission control unit 110 in the processing unit 100 is electrically connected to the light source array 1 and transmits a control signal to the light source array 1. The light emission control unit 110 controls the light emitting units to emit light in the light source array 1 and the timing of light emission using the control signal. In other words, the light emission timing between the light emitting units in the multiple light emitting units changes at a predetermined timing. This allows the light emission control unit 110 to change the angle of incidence of light on the eyeball 30 in a time series. The processing unit 100 is an example of a "processing means for executing processing to detect the tilt position of the eyeball", and the light emission control unit 110 is an example of a "light emission control means".

[0029] Pupil position calculation section 120 is electrically connected to light position detection element 4, and receives a detection signal output by light position detection element 4 in accordance with the position of light incident on the light receiving surface of light position detection element 4. Pupil position calculation section 120 calculates the position of pupil 31 based on the detection signal. Pupil position calculation section 120 is an example of a "position calculation means".

[0030] When the direction of the reflected light from the eyeball 30 changes due to eyeball movement such as the rotation of the eyeball 30, the reflected light may miss the light receiving surface of the position-sensitive detector 4. To prevent this, the light emission control unit 110 sequentially or selectively changes the light-emitting units to be emitted in the light source array 1. When the light-emitting units are changed, the position of the light emission changes in the plane in which the light-emitting units are arranged in the light source array 1, and the angle of incidence of the light incident on the eyeball 30 via the lens 2 and the plane mirror 3 changes. The change in the angle of incidence on the eyeball 30 changes the position of the light reflected by the eyeball 30 and incident on the light receiving surface of the position-sensitive detector 4. Therefore, by changing the light-emitting units to be emitted in the light source array 1 according to the eyeball movement of the eyeball 30, it is possible to prevent the reflected light from the eyeball 30 from missing the light receiving surface of the position-sensitive detector 4.

[0031] The signal detected by the light position detection element 4 indicates a change in the position at which light is reflected on the eyeball 30. The pupil position calculation section 120 calculates the angle of rotation of the eyeball 30 and the pupil position based on the detection signal from the light position detection element 4.

[0032] Fig. 2 is a diagram for explaining an example of the operation of pupil position detection by the pupil position detection device 10. Fig. 2 shows the behavior of light emitted from two light-emitting units at different positions in the light source array 1. Light 1a from one light-emitting unit is represented by a dotted line, and light 1b from the other light-emitting unit is represented by a dashed line. Also, (a) shows the eyeball 30 when in normal vision, that is, when the eyeball 30 is facing forward, and (b) shows the eyeball 30 when it is rotating.

[0033] In (a), light 1a indicated by a dotted line is reflected by the eyeball 30 and enters near the center of the light receiving surface of the position detection element 4. Therefore, the position detection element 4 can detect a change in the incident position of light 1a on the light receiving surface in accordance with the rotation of the eyeball 30. The pupil position calculation unit 120 can calculate the position of the pupil 31 based on the detection signal of the position detection element 4. On the other hand, light 1b indicated by a dashed dotted line does not enter the light receiving surface of the position detection element 4 after being reflected by the eyeball 30. Therefore, light 1b does not contribute to the detection signal of the position detection element 4. Therefore, the pupil position calculation unit 120 cannot calculate the position of the pupil 31.

[0034] On the other hand, as shown in (b), when the eyeball 30 rotates significantly compared to (a), the light 1a that was incident on the light-receiving surface of the position detection element 4 during normal vision moves away from the light-receiving surface of the position detection element 4 and no longer contributes to the detection signal of the position detection element 4. This means that the pupil position calculation unit 120 cannot calculate the position of the pupil 31. On the other hand, the light 1b is incident near the center of the light-receiving surface of the position detection element 4. This means that the position detection element 4 can detect a change in the incident position of the light 1b on the light-receiving surface in response to the rotation of the eyeball 30. The pupil position calculation unit 120 can calculate the position of the pupil 31 based on the detection signal of the position detection element 4.

[0035] Thus, while light from one light-emitting unit can only detect the eye movement of the eyeball 30 within a limited angle range, in this embodiment, the light-emitting units of the light source array 1 are changed to change the angle of incidence onto the eyeball 30, thereby expanding the detection range for the eye movement of the eyeball 30. This makes it possible to expand the detection range for the position of the pupil 31.

[0036] The light-emitting units of the light source array 1 are changed in a time series manner in response to the eyeball movement of the eyeball 30 by a control signal from the light-emitting control unit 110. By controlling the light-emitting units in response 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 required to "respond to eyeball movement." For example, the light-emitting unit position can be raster-scanned at regular time intervals independently of the eyeball movement to obtain the coarse movement position of the eyeball.

[0037] 2 illustrates light emitted from only two light-emitting elements for the sake of simplicity, but in this embodiment, more light-emitting elements provided in the light source array 1 can be used in accordance with the eye movement of the eyeball 30. In this case, the number and positions of the light-emitting elements of the light source array 1 are optimized in accordance with the size of the light-receiving surface of the light position detection element 4 and the size of the eyeball so that the position of the pupil 31 is properly detected.

[0038] FIG. 3 is a functional block diagram showing an example of a hardware configuration of the processing unit 100 of the present embodiment.

[0039] The processing unit 100 has 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 connected to each other via a system bus 105.

[0040] The CPU 101 comprehensively controls the operation of the processing unit 100. The CPU 101 also executes a process for calculating the position of the pupil 31 based on a detection signal from the light position detection element 4.

[0041] The CPU 101 executes the above-mentioned control and processing by executing programs stored in the ROM 102 or the like using the RAM 103 as a work area, thereby 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).

[0042] The input / output I / F 104 is an interface for connecting to external devices such as a PC (Personal Computer) and video equipment.

[0043] Fig. 4 is a diagram showing an example of components of the processing unit 100 of this embodiment in the form of functional blocks. Note that each functional block shown in Fig. 4 is conceptual, and does not necessarily have to be physically configured as shown in the figure. All or a part of each functional block can be functionally or physically distributed and connected in any unit. All or any part of each processing function performed by each functional block can be realized by a program executed by the above-mentioned CPU 101, or can be realized as hardware using wired logic.

[0044] As described above, the processing unit 100 has the light emission control unit 110 and the pupil position calculation unit 120. The function of the light emission control unit 110 is as described above. The pupil position calculation unit 120 has a detection signal receiving unit 121, an eye rotation angle estimation unit 122, and a pupil center position calculation unit 123.

[0045] The detection signal receiving section 121 receives the detection signal output by the light position detection element 4 , and outputs it to the eyeball rotation angle estimating section 122 .

[0046] The eyeball rotation angle estimating section 122 estimates the rotation angle of the eyeball 30 based on the detection signal of the light position detecting element 4 , and outputs the estimated rotation angle to the pupil center position calculating section 123 .

[0047] The pupil center position calculation unit 123 calculates the center position of the pupil 31 based on the rotation angle of the eyeball 30 .

[0048] FIG. 5 is a flowchart showing an example of processing by the pupil position calculation unit 120 of this embodiment.

[0049] Prior to step S61, as a preparation for calculating the pupil position, the angle at which the light emitted from the light source array 1 enters the eyeball 30 is designed, and a formula for calculating the rotation angle of the eyeball 30 is determined.

[0050] The calculation formula for the rotation angle of the eyeball 30 is a linear function or a quadratic function. However, this is not limited to this. The formula may be in any form as long as the rotation angle is determined from the designed light incident angle and the landing position of the reflected light on the light position detection element. As a simple approximation, a quadratic function calculation formula is used in the simulation.

[0051] A model of the surface shape of the eyeball 30 is used to design the angle at which light enters the eyeball 30. A simplified model eye and the like have long been known as a general model of the eyeball surface shape (see, for example, "Optical Mechanism of the Eye," Precision Machinery 27-11, 1961).

[0052] A plane mirror 3 (see Figs. 1 and 2) is disposed at the focusing point of the light emitted from the light source array 1. The light reflected by the plane mirror 3 enters the eyeball 30. The light incident on the eyeball 30 is reflected by the eyeball 30 rotated by a predetermined angle and propagates towards the position-sensitive detector 4. The angle of the light incident on the eyeball 30 is calculated and designed in advance by ray tracing calculations or the like so that this propagating light is incident on the center position of the light-receiving surface of the position-sensitive detector 4.

[0053] The incident position of light on the light receiving surface of the optical position detection element 4 can be theoretically analyzed based on the incident angle of light on the eyeball 30, the reflection position of the light on the eyeball 30, and the inclination of the tangent plane of the surface of the eyeball 30. From the solution of such theoretical analysis, an inverse calculation formula (approximation formula) for estimating the rotation angle of the eyeball 30 by polynomial approximation is determined.

[0054] The above is the advance preparation performed for calculating the pupil position prior to step S61 in Fig. 5. The angle of light incident on the eyeball 30 and the inverse calculation formula for estimating the rotation angle of the eyeball 30 are stored in a memory such as the ROM 102 of the processing unit 100, and are referred to and used in the light emission control by the light emission control unit 110 and in the pupil position calculation by the pupil position calculation unit 120.

[0055] 5, first, the light emission control unit 110 causes at least one of the light emitting units of the light source array 1 to emit light at a predetermined timing according to a predesigned angle of incidence of light. The light position detection element 4 detects the position at which light emitted from the light source array 1 and reflected by the eyeball 30 enters the light receiving surface of the light position detection element 4, and outputs the position to the processing unit 100. In the processing unit 100, the detection signal receiving unit 121 of the pupil position calculation unit 120 receives a detection signal from the light position detection element 4 (step S61). The detection signal receiving unit 121 outputs the detection signal to the eyeball rotation angle estimation unit 122.

[0056] Next, 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 (step S63). The eyeball rotation angle estimation unit 122 outputs the calculated eyeball rotation angle to the pupil center position calculation unit 123.

[0057] The pupil center position calculation unit 123 calculates the pupil center position based on the input eyeball rotation angle, using a model of the eyeball surface shape (step S65).

[0058] In this manner, the position of the pupil 31 in the eyeball 30 can be detected.

[0059] FIG. 6 is a diagram for explaining a numerical simulation carried out for verifying the principle of pupil position detection in the pupil position detection device 10 of this embodiment.

[0060] 1, we assume that the plane mirror 3 and the optical position detection element 4 are placed in a plane 10 mm away from the eyeball 30 in the -Z-axis direction. The reference angles (θx, θy) of the eyeball 30 are determined when the rotation angle of the eyeball 30 is changed at five points in the X direction and three points in the Y direction, both in 5° increments.

[0061] The horizontal axis of Figure 6 is the change in the eyeball rotation angle in the X direction, and the vertical axis is the change in the eyeball rotation angle in the Y direction. The rotation angle is changed at five points in the X direction and three points in the Y direction, both in 5° increments, and each incident angle is used as the reference (angle change (0, 0)).

[0062] In the numerical simulation, the exit angle (reflection angle at the plane mirror 3) of light reflected by the eyeball 30 and incident on the center of the position sensitive detector 4 at the position of the plane mirror 3 was calculated by numerical calculation for each reference angle of the eyeball 30. The center of the position sensitive detector 4 is expressed as coordinates (0, 0).

[0063] In addition, the difference (Δθx, Δθy) between the light for each emission angle and the reference angle (θx, θy) of the eyeball 30 was expressed as a quadratic function using an inverse calculation formula estimated from the incident position (x, y) on the light receiving surface of the light position detection element 4, and the coefficients were numerically calculated using a Taylor expansion method.

[0064] 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 normal viewing state is the reference angle. In the graph (a), the grid points are the actual rotation angles of the eyeball 30, and the dots are the estimated positions. When the rotation angle of the eyeball 30 is small, a good match is obtained. In this case, the error is within a maximum of about 0.1° in the range of |Δθx|≦2.5°. Here, the value of 2.5° is half the reference angle in 5° increments, and means the condition for preventing the occurrence of an area where light is not detected. In addition, since a configuration is assumed in which the plane mirror 3 and the optical position detection element 4 are arranged in the X direction in a plane, the error in the Y direction is smaller than that in the X direction.

[0065] 6(b) shows the result when the reference angle is (θx, θy)=(10°, 5°), i.e., when the position of the pupil 31 is located to the upper right from the normal viewing state. The rotation angle of the eyeball 30 is estimated within the same error range as the result of (a).

[0066] 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, i.e., the center position of rotation, and the center position of the cornea, with the Z axis, which is the direction of normal vision. Therefore, the position of the pupil 31 can be calculated as a coordinate that is away 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 positions of the eyeball 30 and the cornea. The distance from the center position of the eyeball 30 to the center position of the cornea is given in advance by an eyeball model.

[0067] In this way, it has been verified by numerical simulation that the calculation process of pupil position calculation section 120 shown in FIG. 5 can calculate the position of pupil 31 with sufficient accuracy.

[0068] As described above, according to this embodiment, the light source array 1 includes a plurality of light-emitting units that emit directional light, and a detection element that detects the position of the light reflected by the eyeball from the light-emitting units. By changing the light-emitting units of the light source array 1 at a predetermined timing, the angle of incidence on the eyeball 30 is changed, and the detection range of the position of the pupil 31 is expanded. In this embodiment, such detection of the pupil position is performed by a non-mechanical configuration without using a movable structure such as a MEMS mirror. This makes it possible to realize detection of the pupil position that is resistant to vibration and external impact. In other words, according to this embodiment, it is possible to provide an eyeball tilt position detection device, such as the pupil position, that is resistant to vibration and external impact.

[0069] According to this embodiment, since there is no moving part such as a MEMS mirror, the amount of light reflected by the eyeball that does not reach the photodetector is reduced, and the light utilization efficiency can be improved. In addition, the influence of noise such as ambient light can be suppressed. Furthermore, since there is no dynamic deformation such as a MEMS mirror, the detection accuracy of the pupil position can be ensured without complicated adjustments.

[0070] According to this embodiment, a two-dimensional or one-dimensional PSD is used as the position sensitive detector 4 to detect the incident position of reflected light of light irradiated onto the eyeball on the light receiving surface of the position sensitive detector 4. Since the position of the incident light is detected without depending on the intensity of the incident light, even if there is a difference in the amount of reflected light due to the reflection position of the light on the eyeball 30, the position of the incident light can be detected with high sensitivity without being affected by the difference in the amount of reflected light. As a result, the tilt position of the eyeball, such as the pupil, can be detected with high accuracy.

[0071] In addition, since no imaging element such as a CCD is used to detect the position of incident light, the processing load of image processing, etc. can be reduced. Furthermore, high speed and real-time detection of the position of the pupil, etc. can be ensured without using expensive components such as a high-speed calculator or large-capacity memory. When a one-dimensional PSD is used as the light position detection element 4, a device for detecting the tilt position of the eyeball, such as the pupil position, can be realized at low cost.

[0072] According to this embodiment, the light source array 1 and the lens 2 are integrated by being arranged on the same substrate. This makes it possible to miniaturize the eyeball tilt position detection device and reduce the assembly load. Note that the first substrate on which the light source array 1 is arranged and the second substrate on which the lens 2 is arranged may be brought into contact with each other to integrate the two, thereby achieving the above-mentioned effect.

[0073] According to this embodiment, since a VCSEL is used for the light source array 1, the light-emitting portion of the VCSEL is changed to change the angle of incidence on the eyeball 30, and the detection range for the position of the pupil 31 can be expanded.

[0074] Although the above describes an example of a configuration including one light source array 1, a configuration including multiple light source arrays may be used. This can further expand the range in which the angle of incidence on the eyeball 30 can be changed, and the detection range for the position of the pupil 31 can be further expanded.

[0075] [Second embodiment] Next, a pupil position detection device according to a second embodiment will be described with reference to Fig. 7. In the second embodiment, the description of the same components as those in the embodiments already described may be omitted.

[0076] FIG. 7 is a diagram showing an example of the configuration of a pupil position detecting device 10b of this embodiment.

[0077] In the pupil position detection device 10b, a light position detection element 4 is disposed in the direction of retroreflection of light incident on the eyeball 30 via the light source array 1 and the lens 2. In other words, the light position detection element 4 is disposed on the same side of the eyeball 30 as the light source array 1.

[0078] The above arrangement is realized by changing the incident position on the eyeball 30 and the position of the reflection point P from the first embodiment.

[0079] According to this embodiment, the light distribution module 5 having the light source array 1, the lens 2, and the substrate 5a can be disposed on the same substrate as the position sensitive detector 4, and these can be integrated. This makes it possible to keep the relative positions of the light distribution module 5 and the position sensitive detector 4 unchanged, making it unnecessary to adjust the positions of the two.

[0080] Other effects are similar to those described in the first embodiment.

[0081] [Third embodiment] Next, a pupil position detecting device according to a third embodiment will be described with reference to Figures 8 and 9. In the first and second embodiments, the description of the same components as those in the embodiments already described may be omitted.

[0082] In the first and second embodiments, an example was shown in which the lens 2 and the plane mirror 3 are used as the light deflection means, but in this embodiment, an example is shown in which light deflection is performed by a method other than these.

[0083] 8(a) shows an example of a light deflection means having a microlens array 2a and a reflecting mirror 2b. The light distribution module 6 has a light source array 1, a microlens array 2a, a reflecting mirror 2b, and a substrate 6a.

[0084] As shown in (a), the light emitting units of the light source array 1 and the lenses of the microlens array 2a are arranged in a one-to-one relationship. The light emitting units are also arranged shifted in the X-axis and Y-axis directions with respect to the optical axes of the lenses of the microlens array 2a, with the amount of shift differing for each light emitting unit. The deflection angle of the light from the light emitting units is adjusted by the amount of shift.

[0085] By arranging the substrate on which the microlens array 2a is formed in contact with the substrate of the light source array 1, the light distribution module 6 can be made smaller and thinner. In addition, the deflection angle of the light from the light emitting unit can be adjusted easily and with high precision. In other words, the angle of incidence of the light on the eyeball 30 can be adjusted easily and with high precision. Furthermore, the light distribution module 6 has a reflecting mirror 2b, which enables the light to be folded back, simplifying the mounting of optical components such as the microlens array 2a.

[0086] On the other hand, Fig. 8(b) shows an example of a light deflection means having a concave curved mirror 2c. The light distribution module 7 has a light source array 1, a concave curved mirror 2c, and a substrate 7a. By having the concave curved mirror 2c, the number of optical components can be reduced, and the light can be folded back, simplifying the implementation of the optical components.

[0087] In addition to the above, a diffraction grating, a prism, a hologram element, etc. can be used as the light deflection means. Note that a diffraction grating and a prism are basically one-dimensional deflection elements. Therefore, when using a diffraction grating or a prism as the light deflection means, it is necessary to combine two or more diffraction gratings or prisms whose deflection directions intersect, or to provide an area division structure on the deflection surface of the diffraction grating or prism to deflect the light in two or more intersecting directions.

[0088] Fig. 9 shows an example of a configuration in which the light distribution module 6 shown in Fig. 8(a) is provided on a glasses-type support 20. Note that, although the position sensitive detector 4 is disposed on the glasses frame 21 in Fig. 9, there are no restrictions on the position at which the position sensitive detector 4 is disposed, as long as it is disposed so that reflected light from the eyeball 30 is incident on the light receiving surface of the position sensitive detector 4.

[0089] According to this embodiment, the light deflection means is any one or a combination of two or more of a partial region of a convex lens, a plane mirror, a microlens array, a concave curved mirror, a hologram diffraction element, a prism array, or a diffraction grating. This makes it possible to change the angle of incidence on the eyeball 30 and expand the detection range for the position of the pupil 31. Since light deflection is performed with a simple configuration that does not have moving parts, the eyeball tilt position detection device can be made smaller and the assembly load can be reduced.

[0090] According to this embodiment, the light source array 1 and the light deflection means such as a microlens array are arranged on the same substrate to integrate the two. This makes it possible to miniaturize the eyeball tilt position detection device and reduce the assembly load. Note that the substrate on which the light source array 1 is arranged and the substrate on which the light deflection means such as the microlens array 2a is arranged may be brought into contact with each other to integrate the two and obtain the above-mentioned effect.

[0091] Other effects are similar to those described in the first and second embodiments.

[0092] [Fourth embodiment] Next, a display device according to a fourth embodiment will be described with reference to Fig. 10. In the first to third embodiments, the description of the same components as those in the embodiments already described may be omitted.

[0093] FIG. 10 is a diagram showing an example of the configuration of a display device 50 of this embodiment.

[0094] The display device 50 includes an RGB (Red, Green, Blue) laser light source 51, a scanning mirror 52, a plane mirror 53, a half mirror 54, an image generating means 55, and a pupil position detecting device 10b.

[0095] The RGB laser light source 51 modulates the three RGB color laser light beams over time and outputs them. The scanning mirror 52 two-dimensionally scans the light from the RGB laser light source 51. The scanning mirror 52 is, for example, a MEMS mirror. Any mirror having a reflecting portion for scanning light, such as a polygon mirror or a galvanometer mirror, may be used. The MEMS mirror is advantageous in terms of size and weight reduction. The driving method of the MEMS mirror may be any of electrostatic, piezoelectric, electromagnetic, etc.

[0096] The plane mirror 53 reflects the scanning light from the scanning mirror 52 toward the half mirror 54. The half mirror 54 transmits a portion of the incident light and reflects a portion of it toward the eyeball 30. The half mirror 54 has a concave curved shape, and converges the reflected light near the pupil 31 of the eyeball 30 to form an image at the position of the retina 32. In this way, the image formed by the scanning light is projected onto the retina 32. Light 51a indicated by a dashed line in the figure represents light that forms an image on the retina 32. It should be noted that the amount of reflected light and transmitted light of the half mirror 54 does not necessarily have to be one to one.

[0097] The pupil position detection device 10 b detects the position of the pupil 31 according to the eye movement, and transmits a feedback signal of the pupil 31 position to the image generation means 55 .

[0098] The image generating means 55 has a function of controlling the deflection angle of the scanning mirror 52 and a function of controlling the light emission of the RGB laser light source 51. The image generating means 55 also receives a feedback signal of the position of the pupil 31 from the pupil position detection device 10b. According to the position of the pupil 31 detected by the pupil position detection device 10b, the deflection angle of the scanning mirror 52 and the light emission of the RGB laser light source 51 are controlled, and the projection angle of the image or the image content is rewritten. This makes it possible to form an image on the retina 32 that tracks (eye-tracks) the change in the position of the pupil 31 accompanying eye movement.

[0099] The above shows an example in which the display device 50 is a head mounted display (HMD) that is a wearable terminal. The display device 50 as a head mounted display may be directly attached to the head of a "person" or indirectly attached to the head of a "person" via a member such as a fixing part. Also, a binocular display device having a pair of display devices 50 for the left and right eyes may be used.

[0100] Here, the device described in Patent Document 1 will be compared with the pupil position detection devices 10, 10a, and 10b of the present embodiment.

[0101] In the device described in Patent Document 1, a laser light source is used, and the laser light is scanned by a MEMS mirror to change the angle of incidence of the light on the eyeball 30. In contrast, in the present embodiment, a light source array 1 having a plurality of light emitting units is used as a light source, and the angle of incidence of the light on the eyeball 30 is changed by changing the light emitting units of the light source array 1. In addition, in the present embodiment, the range of change of the angle of incidence is expanded by using a light deflection means (lens, flat mirror, microlens array, concave curved mirror, hologram diffraction element, prism array, diffraction grating, etc.) in combination with the light source array 1. In this manner, in the present embodiment, the angle of incidence of the light on the eyeball 30 is changed without using a movable part. Therefore, compared with a configuration having a movable object, it is more resistant to vibration, external impact, and the like.

[0102] In the device described in Patent Document 1, the reflected light intensity of light irradiated onto the cornea is detected by a photodetector, whereas in this embodiment, a two-dimensional light position detection element 4 such as a PSD is used to detect the position of light reflected by the eyeball 30 and incident on the light receiving surface of the light position detection element 4. Since the PSD detects the position of incident light without depending on the light intensity, even if there is a difference in the amount of reflected light due to the reflection position of the light on the eyeball 30, it is possible to perform highly sensitive position detection without being affected by the difference in the amount of reflected light. As a result, the tilt position of the eyeball, such as the pupil, can be detected with high accuracy.

[0103] In this embodiment, a light emission control unit 110 is provided, and the light emission control unit 110 shifts the positions of the light emitting units of the light source array 1 and the light emission timing between the light emitting units to individually light up. This makes it possible to capture coarse movement of the eyeball 30, to ensure that the reflected light from the eyeball 30 falls on the light receiving surface of the optical position detection element 4, and to capture fine movement of the eyeball 30 by position detection by the optical position detection element 4.

[0104] In the device described in Patent Document 1, the eyeball position is estimated from two peak intensities on the time axis of reflected light from the eyeball (two reflection positions on the cornea). In this embodiment, the eyeball position is estimated from the reflection position of one point on the eyeball, such as the cornea. Therefore, the light source array 1 and the light position detection element 4 do not necessarily need to be in symmetrical positions. In this embodiment, the light position detection element 4 may be arranged on the same side as the light source array 1, rather than being arranged near the regular reflection (specular reflection) angle of the eyeball 30.

[0105] Although the image forming apparatus and image forming method according to the embodiment have been described above, the present invention is not limited to the above embodiment, and various modifications and improvements are possible within the scope of the present invention.

[0106] For example, the present invention can be adopted in an optometry device having a function of detecting the inclination of the eyeball and the pupil position (cornea). An optometry device refers to a device capable of performing various tests such as visual acuity tests, eye refractive power tests, intraocular pressure tests, and axial length tests. An optometry device is a device capable of performing tests without contacting the eyeball, and includes a support section for supporting the face of the subject, an eye examination window, a display section for displaying the subject's eyeball (direction of gaze) during eye examination, a control section, and a measurement section. In order to increase the measurement accuracy of the measurement section, the subject is required to gaze at one point without moving the eyeball (gaze), and the subject fixes his / her face on the support section and stares at the display displayed on the display section through the eye examination window. At this time, the eyeball inclination position detection device of this embodiment can be used to detect the inclination position of the eyeball. The eyeball inclination position detection device is disposed to the side of the measurement section so as not to interfere with the measurement. The eyeball tilt position (gaze) information obtained by the eyeball tilt position detection device can be fed back to the control unit, making it possible to perform measurements according to the eyeball tilt position information. [Explanation of symbols]

[0107] 1 Light source array 1a, 1b light 2 Lens (an example of a light deflection means) 2a Microlens array 2b Deflection prism 2c Concave Curved Mirror 3. Plane mirror (an example of an optical deflection means) 4. Optical position sensitive detector 5, 6, 7 Light distribution module 5a, 6a, 7a board 10, 10a, 10b Pupil position detection device 20 Spectacle-shaped support 21 Eyeglass frames 22 Eyeglass Lenses 30 Eyeball 31 Pupil 32 Retina 50 Display device 51 RGB laser light source 52 Scanning Mirror 53 Plane Mirror 54 Half Mirror 55 Image Generation Means 100 Processing section 101 CPU 102 ROM 103 RAM 104 Input / Output Interface 105 System Bus 110 Light emission control unit (an example of a light emission control means) 120 Pupil position calculation unit (an example of a position calculation means) 121 Detection signal receiving unit 122 Eye rotation angle estimation unit 123 Pupil center position calculation unit P reflection point [Prior art documents] [Patent documents]

[0108] [Patent Document 1] US2016 / 0166146 [Non-patent literature]

[0109] [Non-Patent Document 1] IEEE 30th International Conference on Micro Electro Mechanical Systems (MEMS), Las Vegas, 2017, pp.304-307

Claims

1. A device for detecting the tilt position of an eyeball, A light source array including a plurality of light emitting units that emit directional light; a light position detection element that detects the light position of the light reflected from the eyeball; An eyeball tilt position detection device comprising:

2. The light source array has a surface emitting laser in which the light emitting portions are arranged in a plane.

2. The eyeball tilt position detection device according to claim 1.

3. The light emission timing between the light emitting sections of the plurality of light emitting sections is changed at a predetermined timing.

3. The eyeball tilt position detection device according to claim 1, wherein the eyeball tilt position detection device detects an eyeball tilt position.

4. The optical position sensitive detector has a two-dimensional PSD (Position Sensitive Detector).

4. The eyeball tilt position detection device according to claim 1, wherein the eyeball tilt position detection device detects an eyeball tilt position.

5. The optical position sensitive detector has a plurality of one-dimensional PSDs arranged in a predetermined direction.

4. The eyeball tilt position detection device according to claim 1, wherein the eyeball tilt position detection device detects an eyeball tilt position.

6. a light deflection means for directing the light to be incident on the eyeball at a predetermined angle; The optical deflection means is any one of a partial region of a convex lens, a mirror, a microlens array, a concave curved mirror, a hologram diffraction element, a prism array, and a diffraction grating, or a combination of any two or more of them.

6. The eyeball tilt position detection device according to claim 1, wherein the eyeball tilt position detection device detects an eyeball tilt position.

7. The light source array and the light deflection means are disposed on the same substrate.

7. The eyeball tilt position detection device according to claim 6.

8. the light source array is disposed on a first substrate, and the light deflection means is disposed on a second substrate; The first substrate and the second substrate are disposed in contact with each other.

7. The eyeball tilt position detection device according to claim 6.

9. a light deflection means for directing the light to be incident on the eyeball at a predetermined angle; The light source array and the optical deflection means are disposed on the same substrate.

6. The eyeball tilt position detection device according to claim 1, wherein the eyeball tilt position detection device detects an eyeball tilt position.

10. The light position detector is disposed on the same side of the eye as the light source array.

10. The eyeball tilt position detection device according to claim 1, wherein the eyeball tilt position detection device detects an eyeball tilt position.

11. A processing means for executing a process of detecting the inclination position of the eyeball, The processing means includes: a light emission control means for controlling light emission of the light source array; a position calculation means for calculating a tilt position of the eyeball based on an output of the optical position detection element, The light emission control means controls the light emitting unit to emit light and the timing of the light emission.

11. The eyeball tilt position detection device according to claim 1, wherein the eyeball tilt position detection device detects an eyeball tilt position.

12. A display device comprising the eyeball tilt position detection device according to any one of claims 1 to 11.

13. An optometric apparatus comprising the eyeball tilt position detection device according to any one of claims 1 to 11.

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