Video Projection Equipment

Abstract

The purpose of the present invention is to provide a video projection device capable of obtaining a satisfactory video (image) while achieving reductions in power consumption and the size of the device.　Provided is a video projection device equipped with at least a monolithic semiconductor laser array that has a plurality of light emitting units each emitting laser light, an optical wave guide that guides the laser light in a predetermined direction, a mirror that performs scanning with the laser light in two axis directions, and a diffraction element that diffracts the laser light in a specific direction in front of an eye and projects the laser light on a retina, each of the plurality of light emitting units being optically coupled to incidence ports different from each other among a plurality of incidence ports of the optical waveguide.

Description

[Technical field]

[0001] The present technology relates to a video projection device. [Background technology]

[0002] In recent years, attention has been focused on a technology that displays an image superimposed on an external scene such as a real landscape. This technology is also called augmented reality (AR) technology. One product that uses this technology is a head-mounted display. A head-mounted display is used by being worn on a user's head. In an image (image) display method using a head-mounted display, for example, light from the head-mounted display reaches the user's eyes in addition to light from the external world, and an image (image) is displayed superimposed on an image of the external world.

[0003] For example, Patent Document 1 proposes a technique for an image display device such as a head mounted display, which is provided with a light modulation section, and which independently modulates and emits a plurality of laser beams for projection, thereby reducing color shift. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-125905 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, while the technology proposed in Patent Document 1 can reduce color shift in an image by providing a light modulation unit, it may not be possible to reduce power consumption or miniaturize the device because the light modulation unit is provided separately from the light source.

[0006] Therefore, the present technology has been developed in consideration of such circumstances, and its main objective is to provide an image projection device that can obtain good images (pictures) while reducing power consumption and achieving a compact device. [Means for solving the problem]

[0007] The inventors of the present invention have conducted intensive research to achieve the above-mentioned object, and as a result, have surprisingly succeeded in obtaining good video (images) while reducing power consumption and miniaturizing the device, thereby completing the present technology.

[0008] That is, as a first aspect of the present technology, Provided is an image projection device comprising at least a monolithic semiconductor laser array having a plurality of light-emitting units that emit laser light, an optical waveguide that guides the laser light in a predetermined direction, a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects it onto the retina, wherein each of the light-emitting units of the plurality of light-emitting units is optically coupled to a different one of a plurality of entrances of the optical waveguide.

[0009] In the image projection device according to the first aspect of the present technology, The wavelengths of the laser light emitted from each of the plurality of light emitting sections included in the monolithic semiconductor laser array may be substantially the same.

[0010] In addition, as a second aspect of the present technology, a plurality of monolithic semiconductor laser arrays each having at least one light emitting portion that emits laser light; an optical waveguide for guiding the laser light in a predetermined direction; The present invention includes at least a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects the laser light onto the retina, the wavelengths of the laser beams emitted by the at least one light-emitting portion of each of the plurality of monolithic semiconductor laser arrays are different from each other; The present invention provides an image projection device in which the at least one light emitting portion of each of a plurality of monolithic semiconductor laser arrays is optically coupled to different entrances of a plurality of entrances of the optical waveguide.

[0011] In the image projection device according to the second aspect of the present technology, The laser beams having different wavelengths may be multiplexed within the optical waveguide.

[0012] Furthermore, as an image projection device according to a third aspect of the present technology, a plurality of monolithic semiconductor laser arrays each having at least one light emitting portion that emits laser light; an optical waveguide for guiding the laser light in a predetermined direction; The present invention includes at least a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects the laser light onto the retina, At least one of the monolithic semiconductor laser arrays has a plurality of light emitting units, the wavelengths of the laser beams emitted by the light-emitting units of the plurality of light-emitting units included in the at least one monolithic semiconductor laser array are different from each other; The at least one monolithic semiconductor laser array has a plurality of light-emitting sections each of which is optically coupled to a different one of a plurality of light-incident openings of the optical waveguide.

[0013] In the image projection device according to the third aspect of the present technology, The laser beams having different wavelengths may be multiplexed within the optical waveguide.

[0014] In the image projection device according to any one of the first to third aspects of the present technology, the monolithic semiconductor laser array and the optical waveguide are joined via a joining member; The bonding member may have a heat dissipation property and a linear expansion coefficient close to that of the monolithic semiconductor laser array and that of the optical waveguide.

[0015] In the image projection device according to any one of the first to third aspects of the present technology, A distance between at least one of the plurality of exit ports of the optical waveguide may be narrower than a distance between at least one of the plurality of entrance ports of the optical waveguide.

[0016] In the image projection device according to any one of the first to third aspects of the present technology, the optical waveguide has at least three exits; The at least three emission openings may be spaced apart from one another at substantially the same intervals.

[0017] In the image projection device according to any one of the first to third aspects of the present technology, The number of the plurality of output ports of the optical waveguide is N, the angle at which the laser light reflected by the mirror moves in a direction substantially perpendicular to the resonant motion direction of the mirror during a half round trip therebetween is α°; a focal length of a lens that approximately parallelizes the laser light emitted from each of the N emission ports is f; When the distance from the center of a given one of the N exit ports to the center of an adjacent one of the N exit ports is d, The following formula (1) may be satisfied. [Number 1] d = ftan[α(m + 1 / N)] (1) (In the formula (1), m represents an integer of 0 or more.)

[0018] In the image projection device according to any one of the first to third aspects of the present technology, The number of the plurality of output ports of the optical waveguide is N, the angle at which the laser light reflected by the mirror moves in a direction substantially perpendicular to the resonant motion direction of the mirror during a half round trip therebetween is α°; a focal length of a lens that approximately parallelizes the laser light emitted from each of the N emission ports is f; When the distance from the center of a given one of the N exit ports to the center of an adjacent one of the N exit ports is d, The following formula (2) may be satisfied. [Number 2] d = ftan[α(m+1)] (2) (In the formula (2), m represents an integer of 0 or more.)

[0019] In the image projection device according to any one of the first to third aspects of the present technology, The monolithic semiconductor laser array may be of an edge-emitting type.

[0020] In the image projection device according to any one of the first to third aspects of the present technology, The monolithic semiconductor laser array may be of a surface emitting type.

[0021] The image projection device according to any one of the first to third aspects of the present technology may be a head-mounted display.

[0022] The image projection device according to any one of the first to third aspects of the present technology may be an eyewear display.

[0023] According to the present technology, it is possible to provide a video projection device that can obtain good video (images) while reducing power consumption and downsizing the device. Note that the effects described here are not necessarily limited to those described in the present disclosure, and may be any of the effects described in the present disclosure. [Brief description of the drawings]

[0024] [Figure 1]FIG. 1 is a diagram showing an example of the configuration of a video projection device according to a first embodiment to which the present technology is applied. [Diagram 2] FIG. 2 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a second embodiment to which the present technology is applied. [Diagram 3] FIG. 3 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a second embodiment to which the present technology is applied. [Figure 4] FIG. 4 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a third embodiment to which the present technology is applied. [Diagram 5] FIG. 5 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a third embodiment to which the present technology is applied. [Figure 6] FIG. 6 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a fourth embodiment to which the present technology is applied. [Figure 7] FIG. 7 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a fourth embodiment to which the present technology is applied. [Figure 8] FIG. 8 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a fourth embodiment to which the present technology is applied. [Figure 9] FIG. 9 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a fifth embodiment to which the present technology is applied. [Figure 10] FIG. 10 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a fifth embodiment to which the present technology is applied. [Figure 11] FIG. 11 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a fifth embodiment to which the present technology is applied. [Figure 12] FIG. 12 is a diagram illustrating an example of the configuration of a video projection device according to a first embodiment to which the present technology is applied. [Figure 13] FIG. 13 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a fourth embodiment to which the present technology is applied. [Figure 14] FIG. 14 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a fifth embodiment to which the present technology is applied. [Figure 15] FIG. 15 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a fourth embodiment to which the present technology is applied. [Figure 16] FIG. 16 is a diagram showing a configuration example of a monolithic semiconductor laser array and an optical waveguide included in an image projection device according to a fifth embodiment to which the present technology is applied. [Figure 17] FIG. 17 is a diagram illustrating a configuration example of an optical waveguide included in the image projection device according to the first embodiment to which the present technology is applied. [Figure 18] FIG. 18 is a diagram showing the configuration of an example of a direct-retinal imaging type eyewear display. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] A preferred embodiment for implementing the present technology will be described below. The embodiment described below shows an example of a typical embodiment of the present technology, and the scope of the present technology will not be narrowly interpreted by this. Unless otherwise specified, in the drawings, "upper" means the upper direction or upper side in the drawing, "lower" means the lower direction or lower side in the drawing, "left" means the left direction or left side in the drawing, and "right" means the right direction or right side in the drawing. In addition, in the drawings, the same or equivalent elements or members are given the same reference numerals, and duplicated explanations are omitted.

[0026] The explanation will be given in the following order. 1. Overview of this technology 2. First embodiment (example 1 of image projection device) 3. Second embodiment (example 2 of image projection device) 4. Third embodiment (example 3 of image projection device) 5. Fourth embodiment (example 4 of image projection device) 6. Fifth embodiment (example 5 of image projection device)

[0027] 1. Overview of this technology First, an overview of the present technology will be described. The present technology relates to a video projection device.

[0028] A retinal direct imaging type eyewear display will be described with reference to Fig. 18. Fig. 18 is a diagram showing the configuration of an example of a retinal direct imaging type eyewear display.

[0029] As shown in FIG. 18, in a direct-retinal eyewear display 1700, the basic configuration is such that red (R) lasers 701-1R and 701-2R, green (G) lasers 701-1G and 701-2G, and blue (B) lasers 701-1B and 701-2B are combined via mirrors or the like, collimated by lenses or the like, and then scanned in two dimensions by mirrors 702-1 and 702-2 that scan in two-axis directions (e.g., a MEMS mirror that scans in two axes, or two MEMS mirrors that scan in one axis, etc.). The light then passes through lenses 502-1 and 502-2 and diffraction elements 412-1 and 412-2 (e.g., a combiner, etc.) and is focused near the pupils E1-1 and E1-2, and projected onto the retina E2-1 and E2-2 to obtain an image. A CAM (camera module) 402-1 (which may be a PD (photodiode)) and a CAM (camera module) 402-2 (which may be a PD (photodiode)) for ice sensing are arranged on the diffraction elements 412-1 (upper side of FIG. 18) and 412-2 (upper side of FIG. 18).

[0030] Retinal imaging eyewear displays can provide high-brightness and focus-free images compared to conventional panel-type displays. On the other hand, there is a demand for a wider angle of view for retinal imaging eyewear displays. However, to achieve a wider angle of view without reducing the resolution, it is necessary to increase the number of scanning lines scanned in one projection, as well as to increase the swing angle of the biaxially scanning mirror (e.g., MEMS mirror, etc.). Increasing the number of scanning lines within a fixed frame (e.g., 60 Hz) requires increasing the resonance frequency of the biaxially scanning mirror (e.g., MEMS mirror, etc.). The increase in the swing angle and the increase in the resonance frequency are in a contradictory relationship, and it is often difficult to achieve both by improving the performance of the biaxially scanning mirror (e.g., MEMS mirror, etc.).

[0031] In response to this, there is a technology that improves the resolution by not increasing the resonant frequency, but by providing multiple light sources that can each be modulated independently, scanning multiple beams of light on a mirror (such as a MEMS mirror) that scans in the same two-axis direction, and projecting them so that they do not overlap with each other.

[0032] As a first alternative technology, the resolution can be improved by splitting the laser light into multiple beams on the optical waveguide, modulating each beam independently, and projecting them. By providing an optical modulation section in a separate section from the light source, the temperature change of the light source is suppressed, and the phenomenon in which the diffraction angle of the diffractive element changes due to wavelength fluctuation, causing the optical axis to shift, is suppressed. However, with this method, the laser light must always be kept at maximum output to match the brightest part of the image, which places a heavy burden on power consumption. Furthermore, since an optical modulation section must be provided on the optical waveguide for each branched optical path, there is a risk that the size of the device (element) will increase.

[0033] Furthermore, as a second different technology, there is a method of generating multiple beams using multiple laser beams, particularly a monolithic semiconductor laser array, in a laser scanning projector. However, when multiple light sources are arranged, highly accurate arrangement of the light emitting points requires advanced mounting technology, and there is a concern that the light emitting points may shift due to changes in environmental temperature. In addition, with the method of arranging multiple light sources using a monolithic semiconductor laser array, the light emitting points can be arranged with high accuracy, but the light emitting points are spaced at approximately 100 μm from the viewpoint of the structure of the semiconductor laser and heat dissipation, so that the deviation of the projection position on the image becomes large, and when the area where the projections of each light emitting point overlap is cut out from the image, the effective area of ​​the image may become narrow.

[0034] The present technology has been made in consideration of the above circumstances. According to the present technology, it is possible to provide a video projection device that can obtain a good video (image) while realizing reduction in power consumption and miniaturization of the device.

[0035] More specifically, according to the present technology, by arranging multiple laser beams on the screen (on the retina) so that they do not overlap, the number of scanning lines in the screen can be increased, and a wide angle of view can be achieved without reducing the resolution. Also, according to the present technology, if the angle of view is constant, a high-resolution image can be obtained. Furthermore, according to the present technology, when the output of the laser is a constraint on the brightness of the screen, the brightness of the screen can be improved by arranging multiple laser beams on the screen so that they overlap. Incidentally, the present technology can be applied to head-mounted displays, eyewear displays, projectors, and the like.

[0036] The spacing between the light-emitting points of the monolithic semiconductor laser array (spacing between the light-emitting sections) and the spacing between the entrances of the optical waveguide are arranged with high precision (e.g., equal spacing) using semiconductor lithography, and they are connected (joined) directly (through air) or through a material that has high heat dissipation properties and a linear expansion coefficient close to (or approximately equal to) that of the monolithic semiconductor laser array or the optical waveguide, or both the monolithic semiconductor laser array and the optical waveguide, resulting in high optical coupling efficiency and robustness against changes in environmental temperature.

[0037] Narrowing the spacing between the laser beams in the optical waveguide minimizes the narrowing of the angle of view. The spacing between the exit ports of the optical waveguide is also precisely positioned, making it easy to position the images without the beams overlapping when projected, and the relationship between the spacing between the exit ports is maintained even when the environmental temperature changes.

[0038] When multiple light beams are projected onto the retina using a diffraction element, the diffraction angle may differ depending on the wavelength, but by using a monolithic semiconductor laser array, the array is created on the same substrate using the same process, making it possible to unify the wavelength and make the diffraction angle constant. In addition, by combining multiple lights (for example, red light (R light), green light (G light), blue light (B light), etc.) on the optical waveguide, it is possible to make the device more compact.

[0039] Hereinafter, an embodiment of the present technology will be described in detail.

[0040] 2. First embodiment (example 1 of image projection device) The image projection device of a first embodiment (example 1 of image projection device) of the present technology is an image projection device including at least a monolithic semiconductor laser array having a plurality of light-emitting units that emit laser light, an optical waveguide that guides the laser light in a predetermined direction, a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects it onto the retina, and each of the light-emitting units of the plurality of light-emitting units is optically coupled to a different one of a plurality of entrance ports of the optical waveguide.

[0041] The optical waveguide is, for example, a planar optical waveguide that guides light onto a two-dimensional plane. The monolithic semiconductor laser array is, for example, a monolithic semiconductor laser array in which a plurality of light emitting units are formed on the same substrate by semiconductor lithography.

[0042] A video projection device according to a first embodiment of the present technology will be described with reference to FIG. 1, FIG. 12, and FIG. 17. FIG. 1 is a diagram showing a configuration example (video projection device 1000) of a video projection device according to a first embodiment of the present technology. FIG. 12 is a diagram showing a configuration example (video projection device 1200) of a video projection device according to a first embodiment of the present technology. However, it is needless to say that the video projection device according to the first embodiment of the present technology is not limited to the video projection devices 1000 and 1200. FIG. 17 is a cross-sectional view showing an optical waveguide 1-17a and an optical waveguide 1-17b included in the video projection device according to the first embodiment to which the present technology is applied. This cross-sectional view is a view cut in a direction approximately perpendicular to the traveling direction of the laser light (the traveling direction when the laser light travels straight from the entrance). The optical waveguide 1-17a and the optical waveguide 1-17b can be applied to the video projection devices according to the second to fifth embodiments of the present technology described later.

[0043] First, an explanation will be given with reference to FIG.

[0044] The image projection device 1000 includes a monolithic semiconductor laser array 2 in which a plurality of light-emitting elements (three points in FIG. 1, light-emitting elements Q1 to Q3) are formed by semiconductor lithography on the same substrate, and the wavelengths (which may be wavelength bands) of the plurality of light-emitting elements are approximately the same, an optical waveguide 1 (e.g., a planar optical waveguide) that guides laser light onto a two-dimensional plane, a mirror 700 (e.g., a MEMS (Micro Electro Mechanical Systems) mirror) that scans the laser light in two axial directions, and a diffraction element 800 (e.g., a hologram element) that diffracts the laser light in a specific direction in front of the eye and projects it onto the retina E2.

[0045] The monolithic semiconductor laser array 2 and the optical waveguide 1 are joined directly (through air) or through one material (Si, AlN, etc.) (excluding the amount of adhesive) that has high heat dissipation and a linear expansion coefficient close to (or substantially equal to) the monolithic semiconductor laser array 2 or the optical waveguide 1, or both the monolithic semiconductor laser array 2 and the optical waveguide 1, and each of the light emitting parts Q1 to Q3 of the monolithic semiconductor laser array 2 is optically coupled to each of different inlets V1 to V3 of the optical waveguide. That is, in FIG. 1, Q1 and V1 are optically coupled directly (through air), Q2 and V2 are optically coupled directly (through air), and Q3 and V3 are optically coupled directly (through air).

[0046] The intervals between the exit ports W1-W3 of the optical waveguide 2 coupled to the monolithic semiconductor laser array 2 (in FIG. 1, the interval between the exit port W1 and the exit port W2, and the interval between the exit port W2 and the exit port W3) are narrower than the intervals between the entrance ports (the interval between V1 and V2, and the interval between V2 and V3). When there are three or more light-emitting units, the intervals between the exit ports are equal. In the image projection device 1000 in FIG. 1, there are three light-emitting units Q1-Q3, so the intervals between the exit ports W1-W3 of the optical waveguide 2 are equal (i.e., the interval between W1 and W2 and the interval between W2 and W3 are approximately the same length).

[0047] With the above configuration (image projection device 1000 in FIG. 1), by arranging multiple laser beams on the screen so that they do not overlap, the number of scanning lines on the screen can be increased, making it possible to widen the angle of view without reducing the resolution. Furthermore, with the above configuration (image projection device 1000 in FIG. 1), it is possible to obtain high-resolution images if the angle of view is constant. With the above configuration (image projection device 1000 in FIG. 1), if the laser output is a constraint on the brightness of the screen, the brightness of the screen can be improved by arranging multiple laser beams on the screen so that they overlap.

[0048] Using a diffraction element 800 (e.g., a hologram element) is an effective means for manufacturing a small eyewear display, but it has a large wavelength dispersion. Therefore, in the case of multi-beam generation, a monolithic laser array is used to unify the wavelength and diffract multiple light beams in the same direction.

[0049] On the other hand, if an image is projected using only the monolithic laser array 2, the distance between the light emitting points is too wide (up to 100 μm), narrowing the angle of view. Therefore, by combining it with the optical waveguide 1, it is possible to narrow the distance between the light emitting points, and the narrowing of the angle of view can be avoided. Furthermore, since the optical waveguide 1 and the monolithic laser 2 are formed by semiconductor lithography, it is possible to control the coupling distance for multiple light beams, making optical coupling easy.

[0050] As described above, the optical waveguide 1 and the monolithic laser 2 are optically coupled directly (through air) or through one material (Si, AlN, etc.) (excluding the amount of adhesive) that has high heat dissipation and a linear expansion coefficient close to (or approximately equal to) that of the monolithic semiconductor laser array 2 or the optical waveguide 1, or both the monolithic semiconductor laser array 2 and the optical waveguide 1, so that the optical waveguide 1 is robust against environmental changes. Furthermore, by multiplexing the red laser light, green laser light, and blue laser light using the optical waveguide 1, the device can be made smaller and color shift due to temperature can be suppressed.

[0051] Ideally, the multiple scanning lines should be equally spaced and have different scanning optical paths. For example, if the number of exit ports is N and the interval between the scanning lines (Scan1 to Scan3) scanned by the MEMS mirror is d1, the angle of each scanning line should be set by the following formula with a certain scanning line as the reference.

[0052] [Number 3] d(m1+1 / N), d(m2+2 / N)...d(m n-1 +(N-1) / N)(m1~m n-1 is an integer greater than or equal to 0.) Here, the interval d1 between the scanning lines is defined as the angle that the scanning lines move vertically while making one round trip in the horizontal direction.

[0053] The angle of the scanning line is determined by the interval between the exit ports of the optical waveguide and the focal length of the collimator lens. If the focal length of the collimator lens is f, the interval between the exit ports is expressed as follows, It is desirable to set it according to the following formula.

[0054] [Number 4] ftan[d(m1+1 / N], ftan[d(m2+2 / N], ... ftan[d(m n-1 +(N-1) / N]

[0055] For example, assuming that the number of exit ports (light emitting points) is three (exit ports W1 to W3), the scanning line interval is 0.06 deg, the focal length of the collimator lens 500 is 5 mm, m1 = 1, and m2 = 2, the intervals between the exit ports W1 to W3 of the optical waveguide 1 are 6.98 μm and 13.96 μm when calculated based on the following formula using a certain exit port (for example, exit port W1) as the reference.

[0056] [Number 5] 5*tan[0.06*(1+1 / 3)]=6.98μm [Number 6] 5*tan[0.06*(2+2 / 3)]=13.96μm

[0057] If the spacing between the exit ports (light emitting points) is too wide, it will narrow the effective area of ​​the image, but if the spacing between the exit ports (light emitting points) is too narrow, transitions will occur between the cores of the optical waveguide, adversely affecting the image, so a spacing of about a few μm is appropriate.

[0058] If the spacing between the emission apertures (light-emitting points) is three or more, the above formula can be satisfied even if the apertures are not equally spaced. However, in order to satisfy the above formula while minimizing the effect of narrowing the effective image area, equal spacing is the best condition.

[0059] Next, with reference to FIG. 12, a case where a plurality of laser lights (light beams) do not overlap on a screen (eg, on the retina) and a case where they overlap will be described.

[0060] The image projection device 1200 shown in FIG. 12 includes a monolithic semiconductor laser array 2 in which a plurality of light-emitting units (three in total, light-emitting units Q1 to Q3 in FIG. 1) are formed on the same substrate by semiconductor lithography, and the wavelengths (or wavelength bands) of the plurality of light-emitting units are substantially the same, an optical waveguide 1 (e.g., a planar optical waveguide) that guides the laser light onto a two-dimensional plane, and a mirror 700 that scans the laser light in two axial directions. The image projection device 1200 may or may not include a diffraction element. If the image projection device 1200 includes a diffraction element, the diffraction element can diffract the laser light in a specific direction in front of the eye and project it onto the retina, and the image projection device 1200 can be applied to eyewear displays, head-mounted displays, and the like. If the image projection device 1200 does not include a diffraction element, it can be applied to a scanning projector that can project an image onto a screen.

[0061] When multiple laser light beams (light beams) do not overlap on a screen (e.g., on the retina), it is expressed by the following equation (1).

[0062] [Number 7] d = ftan[α(m + 1 / N)] (1)

[0063] In the formula (1), N is the number of the exits of the optical waveguide 1, and in FIG. 12, there are three exits W1 to W3. α° shown in FIG. 12 is the angle at which the laser beams LR1 to LR3 reflected by the mirror 700 move in a direction substantially perpendicular to the resonant direction of the mirror 700 (for example, the horizontal direction) while making a half round trip in the resonant direction of the mirror 700. That is, α° shown in FIG. 12 is the angle at which the laser beams LR1 to LR3 reflected by the mirror 700 move in a direction substantially perpendicular to the resonant direction while making a half round trip in the resonant direction of the mirror 700 (for example, the horizontal direction). f shown in FIG. 12 is the focal length of the lens 500 that makes the laser beams LR1 to LR3 emitted from the exits W1 to W3 substantially parallel. d shown in FIG. 12 represents the distance from the center of the exit W1 to the center of the exit W2 and the distance from the center of the exit W2 to the center of the exit W3. m represents an integer of 0 or greater.

[0064] When multiple laser light beams (light beams) overlap on a screen (e.g., on the retina), it is expressed by the following equation (2).

[0065] [Number 8] d = ftan[α(m+1)] (2)

[0066] In the formula (2), N is the number of the exits of the optical waveguide 1, and in FIG. 12, there are three exits W1 to W3. α° shown in FIG. 12 is the angle at which the laser beams LR1 to LR3 reflected by the mirror 700 move in a direction substantially perpendicular to the resonant direction of the mirror 700 (for example, the horizontal direction) while making a half round trip in the resonant direction of the mirror 700. That is, α° shown in FIG. 12 is the angle at which the laser beams LR1 to LR3 reflected by the mirror 700 move in a direction substantially perpendicular to the resonant direction while making a half round trip in the resonant direction of the mirror 700 (for example, the horizontal direction). f shown in FIG. 12 is the focal length of the lens 500 that makes the laser beams LR1 to LR3 emitted from the exits W1 to W3 substantially parallel. d shown in FIG. 12 represents the distance from the center of the exit W1 to the center of the exit W2 and the distance from the center of the exit W2 to the center of the exit W3. m represents an integer of 0 or greater.

[0067] The optical waveguide 1-17a and the optical waveguide 1-17b will be described with reference to Fig. 17. The optical waveguide 1-17a shown in Fig. 17(a) is formed by embedding three cores 11a in approximately the same layer in a clad 11-1a formed on a substrate 11-2a. The three laser beams are incident on the optical waveguide 1-17a (the three cores 11a embedded in the clad 11-1a) and guided onto a two-dimensional plane.

[0068] 17(b), an optical waveguide 1-17b has three cores 11b formed on a cladding 11-1b formed on a substrate 11-2b. Three laser beams are incident on the optical waveguide 1-17b (the three cores 11b formed on the cladding 11-1b) and guided onto a two-dimensional plane.

[0069] The contents described above regarding the image projection device of the first embodiment (example 1 of image projection device) of the present technology can be applied to the image projection devices of the second to fifth embodiments of the present technology described below, unless there is any particular technical contradiction.

[0070] 3. Second embodiment (example 2 of image projection device) The image projection device of a second embodiment (example 2 of image projection device) of the present technology is an image projection device that at least includes a plurality of monolithic semiconductor laser arrays having at least one light-emitting unit that emits laser light, an optical waveguide that guides the laser light in a predetermined direction, a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects it onto the retina, in which the wavelengths of the laser light emitted by the at least one light-emitting unit of each of the plurality of monolithic semiconductor laser arrays are different from each other, and the at least one light-emitting unit of each of the plurality of monolithic semiconductor laser arrays is optically coupled to different entrances among a plurality of entrances of the optical waveguide.

[0071] The optical waveguide is, for example, a planar waveguide that guides light onto a two-dimensional plane. The monolithic semiconductor laser array is, for example, a monolithic semiconductor laser array in which a plurality of light emitting units are formed on the same substrate by semiconductor lithography.

[0072] The image projection device according to the second embodiment of the present technology will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a top view showing monolithic semiconductor laser arrays 2-3G, 2-3R, and 2-3B and an optical waveguide 1-2 included in the image projection device according to the second embodiment of the present technology, and Fig. 3 is a top view showing monolithic semiconductor laser arrays 2-4G, 2-4R, and 2-4B and an optical waveguide 1-3 included in the image projection device according to the second embodiment of the present technology.

[0073] First, a description will be given with reference to Fig. 2. In Fig. 2, a description will be given of a method for forming a composite wave obtained by combining monolithic semiconductor laser arrays with different wavelengths into multiple beams and emitting the composite wave.

[0074] As shown in Figure 2, by combining red, blue, and green laser light, it is possible to output white laser light (multi-beam), and by independently modulating the light of each wavelength, it is possible to project color images. In detail, in the two green laser beams (multi-beams) LG1 and LG2 emitted from the monolithic semiconductor laser array 2-3G and guided to the optical waveguide 1-2, the two red laser beams (multi-beams) LR1 and LR2 emitted from the monolithic semiconductor laser array 2-3R and guided to the optical waveguide 1-2, and the two blue laser beams (multi-beams) LB1 and LB2 emitted from the monolithic semiconductor laser array 2-3B and guided to the optical waveguide 1-2, the green laser beam LG1, the red laser beam LR1, and the blue laser beam LB1 are combined on or within the optical waveguide 1-2 to output a white laser beam (multi-beam) LW1, and the green laser beam LG2, the red laser beam LR2, and the blue laser beam LB2 are combined on or within the optical waveguide 1-2 to output a white laser beam (multi-beam) LW2.

[0075] In the image projection device of the second embodiment, multi-beam control and multiple wavelength multiplexing are realized simultaneously on the optical waveguide, which enables miniaturization. In addition, in Fig. 2, two multi-beams are used to multiplex three wavelengths, but the number of multi-beams and the number of multiplexed beams are not limited to this.

[0076] Next, an explanation will be given with reference to Figure 3. As shown in Figure 3, instead of combining multiple beams of different wavelengths, it is also possible to emit the beams by bringing the light emitting points closer together.

[0077] In detail, as shown in FIG. 3, two green laser beams (multi-beams) LG1 and LG2 emitted from the monolithic semiconductor laser array 2-4G and guided to the optical waveguide 1-3, two red laser beams (multi-beams) LR1 and LR2 emitted from the monolithic semiconductor laser array 2-4R and guided to the optical waveguide 1-3, and two blue laser beams (multi-beams) LB1 and LB2 emitted from the monolithic semiconductor laser array 2-4B and guided to the optical waveguide 1-3 are not combined on or within the optical waveguide 1-3, but are emitted with their light emitting point distances (light emitting point intervals) brought closer to each other.

[0078] When projecting images, images without any misalignment can be obtained by adjusting the delay on the control board when modulating and outputting the light of each wavelength with a video signal. Compared to the embodiment, the effective area of ​​the image is somewhat narrowed by delay correction, but there is no loss that occurs when multiplexing different wavelengths, so the efficiency of light utilization is improved.

[0079] The contents described above regarding the image projection device of the second embodiment (example 2 of image projection device) of the present technology can be applied to the image projection device of the first embodiment of the present technology described above and the image projection devices of the third to fifth embodiments of the present technology described below, unless there is any particular technical contradiction.

[0080] <4. Third embodiment (example 3 of image projection device)> The image projection device of a third embodiment (example 3 of image projection device) of the present technology is an image projection device including at least a plurality of monolithic semiconductor laser arrays having at least one light-emitting unit that emits laser light, an optical waveguide that guides the laser light in a predetermined direction, a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects it onto the retina, wherein at least one of the plurality of monolithic semiconductor laser arrays has a plurality of light-emitting units, the wavelengths of the laser light emitted by each of the plurality of light-emitting units in the at least one monolithic semiconductor laser array are different from each other, and each of the plurality of light-emitting units in the at least one monolithic semiconductor laser array is optically coupled to a different entrance port of a plurality of entrance ports of the optical waveguide.

[0081] The optical waveguide is, for example, a planar waveguide that guides light onto a two-dimensional plane. The monolithic semiconductor laser array is, for example, a monolithic semiconductor laser array in which a plurality of light emitting units are formed on the same substrate by semiconductor lithography.

[0082] The image projection device according to the third embodiment of the present technology will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a top view showing monolithic semiconductor laser arrays 2-5R and 2-5BG and an optical waveguide 1-4 included in the image projection device according to the third embodiment of the present technology, and Fig. 5 is a top view showing monolithic semiconductor laser arrays 2-6R and 2-6BG and an optical waveguide 1-5 included in the image projection device according to the third embodiment of the present technology.

[0083] As described above, the light sources (light emitting units) formed in the monolithic laser array have the same wavelength, but light sources (light emitting units) of different wavelengths may be monolithically manufactured as shown in Figures 4 and 5. First, an explanation will be given with reference to Figure 4. As shown in Figure 4, the light may be emitted by bringing the light emitting points closer together in an optical waveguide, and the delay may be adjusted on the control board side.

[0084] In detail, as shown in FIG. 4, one red laser light LR emitted from the monolithic semiconductor laser array 2-5R and guided to the optical waveguide 1-4, and one blue laser light LB and one green laser light LG (a total of two laser lights) emitted from the monolithic semiconductor laser array 2-5BG and guided to the optical waveguide 1-4 are not combined on or within the optical waveguide 1-4, but are emitted with their light emitting point distances (light emitting point intervals) brought closer to each other.

[0085] Next, a description will be given with reference to Fig. 5. As shown in Fig. 5, multiplexing may be performed on or within the optical waveguide 1-5.

[0086] In detail, as shown in FIG. 5, one red laser light LR emitted from the monolithic semiconductor laser array 2-6R and guided to the optical waveguide 1-5, and one blue laser light LB and one green laser light LG (total of two laser lights) emitted from the monolithic semiconductor laser array 2-6BG and guided to the optical waveguide 1-5 are combined on or within the optical waveguide 1-5 to output a white laser light (multi-beam) LW.

[0087] The contents described above regarding the image projection device of the third embodiment (example 3 of image projection device) of the present technology can be applied to the image projection devices of the first and second embodiments of the present technology described above, and the image projection devices of the fourth and fifth embodiments of the present technology described below, unless there is any particular technical contradiction.

[0088] <5. Fourth embodiment (example 4 of image projection device)> An image projection device according to a fourth embodiment (example 4 of an image projection device) of the present technology is an embodiment in which an edge-emitting monolithic semiconductor laser array is applied to the image projection device according to the first to third embodiments of the present technology.

[0089] That is, a first aspect of the image projection device of the fourth embodiment of the present technology is an image projection device including at least an edge-emitting monolithic semiconductor laser array having a plurality of light-emitting units that emit laser light, an optical waveguide that guides the laser light in a predetermined direction, a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects it onto the retina, and each of the light-emitting units of the plurality of light-emitting units is optically coupled to a different one of a plurality of incident ports of the optical waveguide.

[0090] Furthermore, a second aspect of the image projection device of the fourth embodiment of the present technology is an image projection device including at least a plurality of edge-emitting monolithic semiconductor laser arrays having at least one light-emitting portion that emits laser light, an optical waveguide that guides the laser light in a predetermined direction, a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects it onto the retina, wherein the wavelengths of the laser light emitted by the at least one light-emitting portion of each of the plurality of edge-emitting monolithic semiconductor laser arrays are different from each other, and the at least one light-emitting portion of each of the plurality of edge-emitting monolithic semiconductor laser arrays is optically coupled to different entrances of the optical waveguide.

[0091] Furthermore, a third aspect of the image projection device of the fourth embodiment of the present technology is an image projection device including at least a plurality of edge-emitting monolithic semiconductor laser arrays having at least one light-emitting portion that emits laser light, an optical waveguide that guides the laser light in a predetermined direction, a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects it onto the retina, wherein at least one of the plurality of edge-emitting monolithic semiconductor laser arrays has a plurality of light-emitting portions, the wavelengths of laser light emitted by the respective light-emitting portions of the plurality of light-emitting portions included in the at least one edge-emitting monolithic semiconductor laser array are different from one another, and the respective light-emitting portions of the plurality of light-emitting portions included in the at least one edge-emitting monolithic semiconductor laser array are optically coupled to respective different entrances of a plurality of entrances included in the optical waveguide.

[0092] The optical waveguide is, for example, a planar waveguide that guides light onto a two-dimensional plane. In an edge-emitting monolithic semiconductor laser array, for example, a plurality of light-emitting sections are formed on the same substrate by semiconductor lithography.

[0093] An image projection device according to a fourth embodiment of the present technology will be described with reference to Figs. 6 to 8, 13, and 15. Fig. 6 is a perspective view showing an edge-emitting monolithic semiconductor laser array 20 and an optical waveguide 1-6 included in the image projection device according to the fourth embodiment of the present technology. Fig. 7 is a cross-sectional view showing an edge-emitting monolithic semiconductor laser array 20-7 and an optical waveguide 1-7 included in the image projection device according to the fourth embodiment of the present technology, and Fig. 8 is a cross-sectional view showing an edge-emitting monolithic semiconductor laser array 20-8 and an optical waveguide 1-8 included in the image projection device according to the fourth embodiment of the present technology.

[0094] FIG. 13(a) in FIG. 13 is a cross-sectional view showing an edge-emitting monolithic semiconductor laser array 20-13 and an optical waveguide 1-13 provided in an image projection device according to a fourth embodiment of the present technology, and FIG. 13(b) is a top view showing an edge-emitting monolithic semiconductor laser array 20-13 and an optical waveguide 1-13 provided in an image projection device according to a fourth embodiment of the present technology.

[0095] Figure 15(a) in Figure 15 is a cross-sectional view showing an edge-emitting monolithic semiconductor laser array 20-15 and an optical waveguide 1-15 provided in an image projection device of the fourth embodiment of the present technology, and Figure 15(b) is a top view showing the edge-emitting monolithic semiconductor laser array 20-15 and an optical waveguide 1-15 provided in an image projection device of the fourth embodiment of the present technology.

[0096] First, an explanation will be given with reference to Fig. 6. Fig. 6 is a perspective view of an optical waveguide 1-6 and an edge-emitting type monolithic semiconductor laser array 20 bonded via a pedestal 30. Laser light LR1, laser light LR2, and laser light LR3 emitted from three light-emitting parts of the edge-emitting type monolithic semiconductor laser array 20 are incident on the optical waveguide 1-6.

[0097] FIG. 7 is a cross-sectional view of the configuration shown in FIG. 6. As shown in FIG. 7, the distance between the light emitting portion (light emitting point) formed on the end face T of the edge-emitting monolithic semiconductor laser array 20-7 and the entrance of the optical waveguide 1-7 can be controlled and mounted by using the base 30. The laser light L emitted from the light emitting portion (light emitting point) of the edge-emitting monolithic semiconductor laser array 20-7 is incident on the core 11 of the optical waveguide 1-7. The base 30 and the optical waveguide 1-7 are joined together via an adhesive portion 31, and the base 30 and the edge-emitting monolithic semiconductor laser array 20-7 are joined together via an adhesive portion 31. The adhesive at the adhesive portion 31 is preferably solder or silver paste, which has high reliability.

[0098] Another example of mounting an edge-emitting monolithic laser array is shown in Fig. 8. As shown in Fig. 8, a recess P8 (a cutout area having a cliff) for mounting an edge-emitting monolithic laser array 20-8 is formed on an optical waveguide 1-8.

[0099] As shown in FIG. 8, the distance between the light emitting portion (light emitting point) formed on the end face T of the edge emitting monolithic semiconductor laser array 20-8 and the entrance of the optical waveguide 1-8 can be controlled and mounted. The laser light L emitted from the light emitting portion (light emitting point) of the edge emitting monolithic semiconductor laser array 20-8 is incident on the core 11 of the optical waveguide 1-8. The edge emitting monolithic semiconductor laser array 20-7 and the optical waveguide 1-8 are joined via an adhesive portion 31. The adhesive at the adhesive portion 31 is preferably solder or silver paste, which are highly reliable. The structure has only one adhesive portion (only the adhesive portion between the edge emitting monolithic semiconductor laser array 20-7 and the optical waveguide 1-8 by the adhesive portion 31), which increases reliability.

[0100] An explanation will be given with reference to Fig. 13. As shown in Fig. 13(a), the distance between the light emitting section (light emitting point) formed on the end face T of the edge-emitting type monolithic semiconductor laser array 20-13 and the entrance of the optical waveguide 1-13 can be controlled and mounted via the base 30. The laser light LR2 emitted from the light emitting section (light emitting point) of the edge-emitting type monolithic semiconductor laser array 20-13 enters the core 11 of the optical waveguide 1-13.

[0101] Fig. 13(b) is a top view corresponding to the cross-sectional view shown in Fig. 13(a). As shown in Fig. 13(b), a base 30 having an area larger than that of the edge-emitting monolithic semiconductor laser array 20-13 is disposed, and the edge-emitting monolithic semiconductor laser array 20-13 is stably mounted on the base 30. Laser beams LR1, LR2, and LR3 emitted from three light-emitting parts (light-emitting points) formed on an end face T of the edge-emitting monolithic semiconductor laser array 20-13 are incident on the core 11 of the optical waveguide 1-13.

[0102] Finally, a description will be given with reference to Fig. 15. As shown in Fig. 15(a), a recess P15 (a cutout region having a cliff) for mounting an edge-emitting type monolithic laser array 20-15 is formed on an optical waveguide 1-15.

[0103] 15, the distance between the light emitting section (light emitting point) formed on the end face T of the edge-emitting type monolithic semiconductor laser array 20-15 and the entrance of the optical waveguide 1-15 can be controlled and implemented. The laser light LR2 emitted from the light emitting section (light emitting point) of the edge-emitting type monolithic semiconductor laser array 20-15 enters the core 11 of the optical waveguide 1-15.

[0104] Fig. 15(b) is a top view corresponding to the cross-sectional view shown in Fig. 15(a). As shown in Fig. 15(b), a base 30 having an area larger than that of the edge-emitting type monolithic semiconductor laser array 20-15 is disposed, and the edge-emitting type monolithic semiconductor laser array 20-15 is stably mounted on the base 30. Laser beams LR1, LR2, and LR3 emitted from three light-emitting parts (light-emitting points) formed on the end face T of the edge-emitting type monolithic semiconductor laser array 20-15 are incident on the core 11 of the optical waveguide 1-15.

[0105] The contents described above regarding the image projection device of the fourth embodiment (example 4 of image projection device) of the present technology can be applied to the image projection devices of the first to third embodiments of the present technology described above, and the image projection device of the fifth embodiment of the present technology described below, unless there is any particular technical contradiction.

[0106] <6. Fifth embodiment (example 5 of image projection device)> An image projection device according to a fifth embodiment (example 5 of an image projection device) of the present technology is an embodiment in which a surface-emitting monolithic semiconductor laser array is applied to the image projection device according to the first to third embodiments of the present technology.

[0107] That is, a first aspect of an image projection device of a fifth embodiment of the present technology is an image projection device including at least a surface-emitting monolithic semiconductor laser array having a plurality of light-emitting elements that emit laser light, an optical waveguide that guides the laser light in a predetermined direction, a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects it onto the retina, and each of the light-emitting elements of the plurality of light-emitting elements is optically coupled to a different one of a plurality of incident ports of the optical waveguide.

[0108] In addition, a second aspect of the image projection device of the fifth embodiment of the present technology is an image projection device including at least a plurality of surface-emitting type monolithic semiconductor laser arrays having at least one light-emitting portion that emits laser light, an optical waveguide that guides the laser light in a predetermined direction, a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects it onto the retina, wherein the wavelengths of the laser light emitted by the at least one light-emitting portion of each of the plurality of surface-emitting type monolithic semiconductor laser arrays are different from each other, and the at least one light-emitting portion of each of the plurality of surface-emitting type monolithic semiconductor laser arrays is optically coupled to different entrances of the optical waveguide.

[0109] Furthermore, a third aspect of the image projection device of the fifth embodiment of the present technology is an image projection device including at least a plurality of surface-emitting type monolithic semiconductor laser arrays having at least one light-emitting portion that emits laser light, an optical waveguide that guides the laser light in a predetermined direction, a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects it onto the retina, wherein at least one of the plurality of surface-emitting type monolithic semiconductor laser arrays has a plurality of light-emitting portions, the wavelengths of laser light emitted by each of the plurality of light-emitting portions possessed by the at least one surface-emitting type monolithic semiconductor laser array are different from each other, and each of the plurality of light-emitting portions possessed by the at least one surface-emitting type monolithic semiconductor laser array is optically coupled to a different entrance from each other among a plurality of entrances possessed by the optical waveguide.

[0110] The optical waveguide is, for example, a planar waveguide that guides light onto a two-dimensional plane. In the end-face type monolithic semiconductor laser array, for example, a plurality of light emitting sections are formed on the same substrate by semiconductor lithography.

[0111] An image projection device according to a fifth embodiment of the present technology will be described with reference to Figs. 9 to 11, 14 and 16. Fig. 9 is a perspective view showing a surface-emitting monolithic semiconductor laser array 200 and an optical waveguide 1-9 included in the image projection device according to the fifth embodiment of the present technology. Fig. 10 is a cross-sectional view showing a surface-emitting monolithic semiconductor laser array 200-10 and an optical waveguide 1-10 included in the image projection device according to the fifth embodiment of the present technology, and Fig. 11 is a cross-sectional view showing a surface-emitting monolithic semiconductor laser array 200-11 and an optical waveguide 1-11 included in the image projection device according to the fifth embodiment of the present technology.

[0112] In Figure 14, Figure 14(a) is a cross-sectional view showing a surface-emitting type monolithic semiconductor laser array 200-14 and an optical waveguide 1-14 provided in an image projection device of a fifth embodiment of the present technology, and Figure 14(b) is a top view showing the surface-emitting type monolithic semiconductor laser array 200-14 and an optical waveguide 1-14 provided in an image projection device of a fifth embodiment of the present technology.

[0113] 16(a) is a cross-sectional view showing a surface-emitting type monolithic semiconductor laser array 200-16 and an optical waveguide 1-16 provided in an image projection device according to a fifth embodiment of the present technology, and FIG. 16(b) is a top view showing the surface-emitting type monolithic semiconductor laser array 200-16 and an optical waveguide 1-16 provided in an image projection device according to a fifth embodiment of the present technology.

[0114] First, a description will be given with reference to Fig. 9. Fig. 9 is a perspective view showing an example of mounting an optical waveguide 1-9 and a surface-emitting type monolithic semiconductor laser array 200. As shown in Fig. 9, the surface-emitting type monolithic semiconductor laser array 200 is mounted on the optical waveguide 1-9. Laser light LR1, laser light LR2, laser light LR3, and laser light LR4 emitted from three light-emitting parts of the surface-emitting type monolithic semiconductor laser array 200 are incident on the optical waveguide 1-9.

[0115] FIG. 10 is an example of the configuration shown in FIG. 9 in a cross-sectional view. As shown in FIG. 10, the surface-emitting monolithic semiconductor laser array 200-10 and the optical waveguide 1-10 are surface-bonded. That is, the lower surface M of the surface-emitting monolithic semiconductor laser array 200-10 and the optical waveguide 1-10 are bonded via an adhesive portion 31. The adhesive at the adhesive portion 31 is preferably solder or silver paste, which are highly reliable. In FIG. 10, the laser light L11-1 (laser light L11-2 reflected by the mirror 30) emitted from the light-emitting portion formed on the lower surface M of the surface-emitting monolithic semiconductor laser array 200-10 is optically coupled to the optical waveguide 1-10 (core 11) via a mirror 39.

[0116] An explanation will be given with reference to FIG. 11. This is an example of the configuration shown in FIG. 9 in a cross-sectional view. As shown in FIG. 11, the surface-emitting monolithic semiconductor laser array 200-11 and the optical waveguide 1-11 are surface-bonded. That is, the lower surface M of the surface-emitting monolithic semiconductor laser array 200-11 and the optical waveguide 1-11 are bonded via an adhesive portion 31. The adhesive at the adhesive portion 31 is preferably made of solder or silver paste, which has high reliability. In FIG. 11, the laser light L12-1 (laser light L12-2 diffracted by the diffraction element 40) emitted from the light-emitting portion formed on the lower surface M of the surface-emitting monolithic semiconductor laser array 200-11 is optically coupled to the optical waveguide 1-11 (core 11) via the diffraction element 40.

[0117] An explanation will be given with reference to Fig. 14. As shown in Fig. 14(a), the surface-emitting monolithic semiconductor laser array 200-11 (the lower surface M of the surface-emitting monolithic semiconductor laser array 200-11) and the optical waveguide 1-14 (diffraction element 40) are surface-bonded. In Fig. 14, the laser light LR-2 emitted from the light-emitting section formed on the lower surface M of the surface-emitting monolithic semiconductor laser array 200-14 through the diffraction element 40 is diffracted by the diffraction element 40 and optically coupled with the optical waveguide 1-14 (core 11).

[0118] Fig. 14(b) is a top view corresponding to the cross-sectional view shown in Fig. 14(a). As shown in Fig. 14(b), laser beams LR1, LR2, and LR3 emitted from three light-emitting parts (light-emitting points) formed on a surface (lower surface) M of the surface-emitting type monolithic semiconductor laser array 200-14 are diffracted by a diffraction element (not shown in Fig. 14(b)) and enter (optically couple) into the core 11 of the optical waveguide 1-13.

[0119] Finally, a description will be given with reference to FIG. 16. As shown in FIG. 16(a), the distance between the light emitting portion (light emitting point) formed on the surface M of the surface emitting type monolithic semiconductor laser array 200-16 and the entrance of the optical waveguide 1-16 can be controlled and mounted by using the pedestal 30. The pedestal 30 in FIG. 16 is composed of a vertical portion (up and down direction in FIG. 16) and a horizontal portion (left and right direction in FIG. 16), and the surface emitting type monolithic semiconductor laser array 200-16 is joined to the vertical portion of the pedestal 30, and the surface emitting type monolithic semiconductor laser array 200-16 is directly joined to the optical waveguide (through air). The horizontal portion of the pedestal 30 is joined to the optical waveguide 1-16. That is, a recess P16 is formed by the base 30 and the optical waveguide 1-16, and the surface-emitting type monolithic semiconductor laser array 200-16 is joined to the base 30, and the surface-emitting type monolithic semiconductor laser array 200-16 is disposed in the recess P16. Moreover, the laser light LR2 emitted from a light-emitting portion (light-emitting point) formed on the surface M of the surface-emitting type monolithic semiconductor laser array 200-16 is incident on the core 11 of the optical waveguide 1-16.

[0120] Fig. 16(b) is a top view corresponding to the cross-sectional view shown in Fig. 16(a). As shown in Fig. 16(b), a base 30 having an area (the sum of the area of ​​the vertical portion and the area of ​​the recess) larger than the area of ​​the surface-emitting type monolithic semiconductor laser array 200-16 is disposed, and the surface-emitting type monolithic semiconductor laser array 200-16 is stably mounted in the recess P16 of the base 30. Laser beams LR1, LR2, and LR3 emitted from three light-emitting portions (light-emitting points) formed on the surface M of the surface-emitting type monolithic semiconductor laser array 200-16 are incident on the core 11 of the optical waveguide 1-16.

[0121] The contents described above regarding the image projection device of the fifth embodiment (example 5 of the image projection device) of the present technology can be applied to the image projection devices of the first to fourth embodiments of the present technology described above, unless there is any particular technical contradiction.

[0122] Note that the embodiments according to the present technology are not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present technology.

[0123] Furthermore, the effects described in this specification are merely examples and are not limiting, and other effects may also be obtained.

[0124] The present technology can also be configured as follows. [1] a monolithic semiconductor laser array having a plurality of light emitting portions for emitting laser light; an optical waveguide for guiding the laser light in a predetermined direction; The present invention includes at least a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects the laser light onto the retina, A video projection device, wherein each of the plurality of light-emitting sections is optically coupled to a different one of a plurality of light-incident openings of the optical waveguide. [2] The image projection device according to [1], wherein the wavelengths of the laser light emitted from each of the plurality of light-emitting sections included in the monolithic semiconductor laser array are substantially the same. [3] a plurality of monolithic semiconductor laser arrays each having at least one light emitting portion that emits laser light; an optical waveguide for guiding the laser light in a predetermined direction; The present invention includes at least a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects the laser light onto the retina, the wavelengths of the laser beams emitted by the at least one light-emitting portion of each of the plurality of monolithic semiconductor laser arrays are different from each other; an image projection device, wherein at least one light emitting portion of each of a plurality of monolithic semiconductor laser arrays is optically coupled to different ones of a plurality of light entrances of the optical waveguide; [4] The image projection device according to [3], wherein the laser beams having different wavelengths are multiplexed within the optical waveguide. [5] a plurality of monolithic semiconductor laser arrays each having at least one light emitting portion that emits laser light; an optical waveguide for guiding the laser light in a predetermined direction; The present invention includes at least a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects the laser light onto the retina, At least one of the monolithic semiconductor laser arrays has a plurality of light emitting units, the at least one monolithic semiconductor laser array has a plurality of light-emitting sections each having a different wavelength of laser light emitted from the light-emitting sections; a plurality of light-emitting sections of the at least one monolithic semiconductor laser array are optically coupled to different light-incident ports of the optical waveguide, the light-incident ports being optically coupled to different light-incident ports of the optical waveguide; [6] The image projection device according to [5], wherein the laser beams having different wavelengths are multiplexed within the optical waveguide. [7] the monolithic semiconductor laser array and the optical waveguide are joined via a joining member; The image projection device described in any one of [1] to [6], wherein the bonding member has heat dissipation properties and a linear expansion coefficient close to the linear expansion coefficient of the monolithic semiconductor laser array and the linear expansion coefficient of the optical waveguide. [8] The image projection device according to any one of [1] to [7], wherein the distance between at least one of the plurality of exit ports of the optical waveguide is narrower than the distance between at least one of the plurality of entrance ports of the optical waveguide. [9] the optical waveguide has at least three exits; The image projection device according to any one of [1] to [8], wherein the intervals between the at least three exit ports are substantially the same.

[10] The number of the plurality of output ports of the optical waveguide is N, the angle at which the laser light reflected by the mirror moves in a direction substantially perpendicular to the resonant motion direction of the mirror during a half round trip therebetween is α°; a focal length of a lens that approximately parallelizes the laser light emitted from each of the N emission ports is f; When the distance from the center of a given one of the N exit ports to the center of an adjacent one of the N exit ports is d, 1. An image projection device according to any one of [1] to [9], which satisfies the following formula (1). [Number 9] d = ftan[α(m + 1 / N)] (1) (In the formula (1), m represents an integer of 0 or more.)

[11] The number of the plurality of output ports of the optical waveguide is N, the angle at which the laser light reflected by the mirror moves in a direction substantially perpendicular to the resonant motion direction of the mirror during a half round trip therebetween is α°; a focal length of a lens that approximately parallelizes the laser light emitted from each of the N emission ports is f; When the distance from the center of a given one of the N exit ports to the center of an adjacent one of the N exit ports is d, 1. An image projection device according to any one of [1] to [9], which satisfies the following formula (2). [Number 10] d = ftan[α(m+1)] (2) (In the formula (2), m represents an integer of 0 or more.)

[12] The image projection device according to any one of [1] to

[11] , wherein the monolithic semiconductor laser array is an edge-emitting type.

[13] The image projection device according to any one of [1] to

[11] , wherein the monolithic semiconductor laser array is a surface-emitting type.

[14] 13. The image projection device according to claim 1, wherein the image projection device is a head-mounted display.

[15] 13. The image projection device according to claim 1, wherein the image projection device is an eyewear display. [Explanation of symbols]

[0125] 1(1-2, 1-3, 1-4, 1-5, 1-6, 1-7, 1-8, 1-9, 1-10, 1-11, 1-13a, 1-13b, 1-14a, 1-14b, 1-15a, 1-15b, 1-16a, 1-16b, 1-17a, 1-17b)...Optical waveguide, 2 (2-3G, 2-3R, 2-3B, 2-4G, 2-4R, 2-4B, 2-5R, 2-5BG, 2-6R, 2-6BG,)...Monolithic semiconductor laser array, 20 (20-7, 20-8, 20-13, 20-15)...Monolithic semiconductor laser array (edge ​​emitting type), 30…Pedestal, 200 (200-10, 200-11, 200-14, 200-16) ... Monolithic semiconductor laser array (surface emitting type), 700...mirror (MEMS mirror), 800...diffraction element (hologram element), 1000, 1200...Image projection equipment, 1700…Eyewear display.

Claims

1. a plurality of monolithic semiconductor laser arrays each having a plurality of light emitting portions for emitting laser light; an optical waveguide for guiding the laser light in a predetermined direction; The present invention includes at least a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects the laser light onto the retina, the wavelengths of the laser beams emitted by the light-emitting portions of each of the monolithic semiconductor laser arrays are different from one another; the plurality of light emitting units of each of the plurality of monolithic semiconductor laser arrays are optically coupled to different entrances of the optical waveguide; The number of the plurality of output ports of the optical waveguide is N, the angle by which the laser light reflected by the mirror moves in a direction substantially perpendicular to the resonant motion direction of the mirror during a half round trip in the resonant motion direction of the mirror is α°; a focal length of a lens that approximately parallelizes the laser light emitted from each of the N emission ports is f; When the distance from the center of a given one of the N exit ports to the center of an adjacent one of the N exit ports is d, An image projection device that satisfies the following formula (1). [Equation 1] d=ftan[α(m+1 / N)]...(1) (In the formula (1), m represents an integer of 0 or more.)

2. A plurality of monolithic semiconductor laser arrays each having a plurality of light emitting portions that emit laser light; an optical waveguide for guiding the laser light in a predetermined direction; The present invention includes at least a mirror that scans the laser light in two axial directions, and a diffraction element that diffracts the laser light in a specific direction in front of the eye and projects the laser light onto the retina, the wavelengths of the laser beams emitted by the light-emitting portions of each of the monolithic semiconductor laser arrays are different from one another; the plurality of light emitting units of each of the plurality of monolithic semiconductor laser arrays are optically coupled to different entrances of the optical waveguide; The number of the plurality of output ports of the optical waveguide is N, the angle by which the laser light reflected by the mirror moves in a direction substantially perpendicular to the resonant motion direction of the mirror during a half round trip in the resonant motion direction of the mirror is α°; a focal length of a lens that approximately parallelizes the laser light emitted from each of the N emission ports is f; When the distance from the center of a given one of the N exit ports to the center of an adjacent one of the N exit ports is d, An image projection device that satisfies the following formula (2). [Equation 2] d=ftan[α(m+1)]...(2) (In the formula (2), m represents an integer of 0 or more.)

3. 2. The image projection device according to claim 1, wherein the wavelengths of the laser light emitted from each of the plurality of light-emitting sections included in the monolithic semiconductor laser array are substantially the same.

4. The image projection device according to claim 1 , wherein the laser beams having different wavelengths are multiplexed in the optical waveguide.

5. The image projection device according to claim 3 , wherein the laser beams having substantially the same wavelength are not multiplexed in the optical waveguide.

6. 2. The image projection device according to claim 1, wherein the monolithic semiconductor laser array and the optical waveguide are joined via a joining member.

7. 4. The image projection device according to claim 1, wherein a distance between at least one of the plurality of exit ports of the optical waveguide is narrower than a distance between at least one of the plurality of entrance ports of the optical waveguide.

8. The image projection device according to claim 7 , wherein the laser light emitted from the plurality of emission ports is scanned along different scanning optical paths.

9. the wavelengths of the laser beams emitted from the light-emitting units of the monolithic semiconductor laser array are substantially the same; The image projection device according to claim 7 , wherein the laser light emitted from the plurality of emission ports is scanned along different scanning optical paths.

10. the optical waveguide has at least three exits; 2. The image projection device according to claim 1, wherein the intervals between the at least three exits are substantially the same.

11. 2. The image projection device according to claim 1, wherein the monolithic semiconductor laser array is of an edge-emitting type.

12. 2. The image projection device according to claim 1, wherein the monolithic semiconductor laser array is of a surface emitting type.

13. 10. The image projection device according to claim 1, which is a head-mounted display.

14. 10. The image projection device according to claim 1, which is an eyewear display.

Images