Abstract: An optical semiconductor device includes an active layer having a plurality of quantum dot layers. The plurality of quantum dot layers include: a first quantum dot layer doped with a p-type impurity; and a second quantum dot layer doped with an n-type impurity and having an emission wavelength different from that of the first quantum dot layer.

Abstract: An image projection device includes a light source, a scanning unit that scans a light beam emitted from the light source, and an optical system that converges a plurality of light beams, which are emitted from the scanning unit at different times, at a convergence point in an eye of a user and then irradiates a retina of the user with the plurality of light beams to project an image, wherein diameters of the plurality of light beams incident on a cornea of the user are adjusted to 0.36 mm or greater and 0.46 mm or less when a half angle of a larger one of a horizontal angle of view and a vertical angle of view of an area where the retina is irradiated with the plurality of light beams at the convergence point is 10° or greater and 30° or less.

Abstract: An image projection device includes a projection unit converging image light beams emitted in different directions from a scanning unit at a first convergence point in user's eye, a reflection unit converging the image light beams at a second convergence point before the projection unit, an optical member being provided between the projection unit and the reflection unit, converting the image light beams into convergent light beams, and causing the image light beams to enter the projection unit as diffusion light beams a drive unit moving the reflection unit, a detection unit detecting a direction in which user's pupil has moved, and a drive control unit controlling the drive unit to move the reflection unit so that incident positions of the image light beams on the optical member change according to the direction in which the pupil has moved.

Abstract: In a semiconductor device, a quantum dot group includes a stack of plural quantum dot layers having different central wavelengths at which respective gains are maximum. A part of or all of the quantum dot layers are stacked so that the central wavelengths sequentially shifts along a stacking direction. The quantum dot group includes a longest wavelength layer group composed of some quantum dot layers including a longest wavelength layer having a longest central wavelength and at least one quantum dot layer stacked on the longest wavelength layer. The longest wavelength layer or the longest wavelength layer group has a larger gain at the central wavelength than the gain at the central wavelength of each of the other quantum dot layers.

Abstract: An image relay device that projects laser light representing an image emitted from a projection device onto the retina is provided. The image relay device includes a projection device, a first optical member, and a second optical member. The projection device includes a light source configured to emit laser light and a scan unit configured to scan the laser light based on image data. The first optical member receives an image light from the projection device and converts the image light which is a parallel light, to light beams of convergent light. The second optical member converts the light beams output from the first optical member into parallel light.

Abstract: The semiconductor laser device includes: an activation layer having at least one first quantum dot layer and at least one second quantum dot layer having a longer emission wavelength than the first quantum dot layer. The gain spectrum of the active layer has the maximum values at the first wavelength and the second wavelength longer than the first wavelength corresponding to the emission wavelength of the first quantum dot layer and the emission wavelength of the second quantum dot layer, respectively. The maximum value of the gain spectrum at the first wavelength is defined as the first maximum value, and the maximum value of the gain spectrum at the second wavelength is defined as the second maximum value. The first maximum value is larger than the second maximum value.

Abstract: A visual sense examination device includes: a beam source that emits a visible beam and an invisible beam; a visible beam optical system that includes a first scanner scanning the visible beam; an invisible beam optical system that includes a second scanner scanning the invisible beam; a detector that detects the invisible beam reflected by a retina of a subject; a controller that performs a first control; a synthesizer that synthesizes the visible beam scanned by the first scanner and the invisible beam scanned by the second scanner; and wherein scanning angles of the visible beam by the first scanner and the invisible beam by the second scanner are substantially the same, and projectable ranges of the visible beam scanned by the first scanner and the invisible light scanned by the second scanner are substantially the same on the retina of the subject.

Abstract: An image projection device incudes a scanning unit that two-dimensionally scans a light beam emitted from a light source, a light guide member that is formed of a glass material through which light beams emitted from the scanning unit at different times pass, has reflection surfaces reflecting the light beams, converges the light beams reflected by the reflection surfaces at a first convergence point in the eye of the user, and then irradiates a retina of the user with the converged light beams, a first optical member that converges the light beams emitted from the scanning unit at a second convergence point before the light guide member and then causes the light beams to enter the light guide member, and a second optical member that is disposed at the second convergence point and causes the light beams to enter a last reflection surface as diffusion lights.

Abstract: An image projection device includes: a light source emitting a light beam; an image input unit inputting image data; a control unit generating an image light beam based on the input image data, and controlling emission of the image light beam from the light source; a scan unit scanning the image light beam emitted from the light source; and a projection optical member illuminating a retina of an eyeball of a user with the image light beam scanned by the scan unit, and projecting an image onto the retina, wherein a diameter of the image light beam at a time when the image light beam enters a cornea of the eyeball is not smaller than 310 ?m and not larger than 800 ?m, and a user having an original visual acuity in a range of 0.04 to 1.2 has an acquired visual acuity of 0.4 or higher.

Abstract: Provided is a vision test device including: a projection unit 10 that projects an image on a retina of a subject with use of a laser beam 50 by two-dimensionally scanning the laser beam; a beam diameter setting unit that sets a beam diameter of the laser beam; and a numerical aperture setting unit that sets a numerical aperture of the laser beam, wherein the projection unit projects, on the retina, a test image for measuring visual information of the subject with use of a laser beam having the set beam diameter and the set numerical aperture.

Abstract: An image projection device includes: a light source that emits a laser beam; a control unit that generates an image light beam, and controls emission of the image light beam; a scan unit that scans the image light beam to convert it into scan light; a first light converging unit that is disposed before a user's eye, converges the scan light at a first convergence point near a pupil, and then irradiates the retina with the scan light to project the image on the retina; and a second light converging unit that converges the scan light at a second convergence point before the first light converging unit, and then irradiates the first light converging unit with the scan light; wherein a scan angle of the scan light is substantially the same size as a convergence angle at which the scan light converges to the first convergence point.

Abstract: An image inspection device includes a mounting unit on which an image projection device that directly projects an image on a retina of a user is to be mounted; a condensing lens that condenses a light beam emitted from the image projection device mounted on the mounting unit; a detector on which an inspection image is projected and detected; and a controller that inspects the inspection image detected by the detector. The image inspection device inspects the image projected by the image projection device, which directly projects the image on the retina of the user.

Abstract: A visual field/visual acuity examination system includes a retinal projection head-mounted display; and a terminal device. The terminal device outputs examination image data to the retinal projection head-mounted display; displays an image on a display; and generates an examination image based on the examination image data and display the examination image on the display. The retinal projection head-mounted display inputs the examination image data from the terminal device; generates an image light beam based on the input examination image data and control emission of the image light beam from a light source; causes a scanning minor to scan the image light beam to generate an examination image light beam; and projects the examination image light beam as the examination image on a retina of an eyeball of a test subject after converging the examination image light beam in a vicinity of a pupil of the eyeball.

Abstract: An image projection device includes: a light source that emits a laser beam; a control unit that generates an image light beam, and controls emission of the image light beam; a scan unit that scans the image light beam to convert it into scan light; a first light converging unit that is disposed before a user's eye, converges the scan light at a first convergence point near a pupil, and then irradiates the retina with the scan light to project the image on the retina; and a second light converging unit that converges the scan light at a second convergence point before the first light converging unit, and then irradiates the first light converging unit with the scan light; wherein a scan angle of the scan light is substantially the same size as a convergence angle at which the scan light converges to the first convergence point.

Abstract: A retinal scanning type eye examination device includes a storage unit configured to store test image data; a laser emitting unit including a laser light source configured to generate an imaging laser beam based on the test image data, the laser emitting unit being configured to project a test image onto a retina of an eyeball of a person subjected to an eye examination by using the imaging laser beam; an optical component configured to cause the imaging laser beam to converge at an inside of the eyeball of the person; a parameter acquiring unit configured to acquire parameter information for a retinal scanning type eyewear, the parameter information including angle information indicating a rotation angle of the laser emitting unit when the laser emitting unit is rotated around a converging point of the laser beam; and an output unit configured to output the parameter information to an external device.

Abstract: In the first embodiment and the second embodiment, the case where an image is projected on the retina 52 of one of the eyes 50 has been described, but an image may be projected on the retinas 52 of both eyes 50. In addition, the scan mirror 14 has been described as an example of a scan unit, but the scan unit may be any element as long as it can scan a light beam. For example, other components such as potassium tantalate niobate (KTN) crystal that is an electro-optic material may be used as the scan unit. The case where the light beam is a laser beam has been described as an example, but the light beam may be light other than the laser beam.

Abstract: An image projection device includes: an optical component reflecting an image light beam that has been converted into a substantially parallel light by a lens and scanned by a scanner; a projection mirror irradiating a retina with the reflected image light beam; a light beam blocking unit located on a light path between the scanner and the lens and having an aperture, wherein the projection mirror has a first region and a second region having a larger light condensing power than the first region, and a light condensing power in a third region, reflecting a light beam to be emitted to the first region of the scanned image light beam, of the optical component is greater than that in a fourth region, reflecting a light beam to be emitted to the second region of the scanned image light beam, of the optical component.

Abstract: An image inspection device includes: a mounting unit on which an image projection device that directly projects an image on a retina of a user is to be mounted; a condensing lens configured to condense a light beam emitted from the image projection device mounted on the mounting unit; and a target projection unit on which an inspection image is to be projected by irradiation with the light beam condensed by the condensing lens; and an inspection unit configured to inspect the inspection image projected on the target projection unit.

Abstract: Provided is a vision test device including: a projection unit 10 that projects an image on a retina of a subject with use of a laser beam 50 by two-dimensionally scanning the laser beam; a beam diameter setting unit that sets a beam diameter of the laser beam; and a numerical aperture setting unit that sets a numerical aperture of the laser beam, wherein the projection unit projects, on the retina, a test image for measuring visual information of the subject with use of a laser beam having the set beam diameter and the set numerical aperture.

Abstract: An image projection device includes: a projection unit that projects an image light beam forming an image onto a pupil of an eyeball of a user to project the image onto a retina of the eyeball; a detection unit that detects a direction in which the pupil has moved relative to a face of the user and a speed of movement of the pupil; and a control unit that performs different controls of the image when the pupil has moved at different speeds in a same direction.