Abstract: This aerial image display device is provided with an optical plate having a plurality of reflective surfaces orthogonal to each other in plan view, a projection device, a specular mirror, and a screen. The mirror includes a counter mirror disposed spaced apart from the optical plate at the opposite side of a focused image M across the optical plate. The projection device and the screen sandwich a light path between the counter mirror and the optical plate at the opposite side of the focused image (M) across the optical plate. The projection light emitted from the projection device is incident on the screen after reflecting from the counter mirror, and then incident on the optical plate after reflecting from the screen and then from the same counter mirror.

Abstract: This aerial image display device is provided with an optical plate having a plurality of reflective surfaces orthogonal to each other in plan view, a projection device, a specular mirror, and a screen. The mirror includes a counter mirror disposed spaced apart from the optical plate at the opposite side of a focused image M across the optical plate. The projection device and the screen sandwich a light path between the counter mirror and the optical plate at the opposite side of the focused image (M) across the optical plate. The projection light emitted from the projection device is incident on the screen after reflecting from the counter mirror, and then incident on the optical plate after reflecting from the screen and then from the same counter mirror.

Abstract: Provided are an optical element and a method for manufacturing the optical element, wherein the concave optical surface of the optical element does not adhere to the metal mold convex surface and excellent mold releasability is ensured by providing the end surface of the optical element with an end section which is continuous to the outer end section of the concave optical surface of the optical element and providing the end section with a tapered section having a tilt with respect to the flat surface formed by the outer end section of the concave optical surface at the time of forming the optical element by means of a liquid drop method. The tapered section can be used for alignment at the time of assembling the light emitting unit, and contributes to process time reduction and prevention of generation of failures.

Abstract: Provided are an optical element and a method for manufacturing the optical element, wherein the concave optical surface of the optical element does not adhere to the metal mold convex surface and excellent mold releasability is ensured by providing the end surface of the optical element with an end section which is continuous to the outer end section of the concave optical surface of the optical element and providing the end section with a tapered section having a tilt with respect to the flat surface formed by the outer end section of the concave optical surface at the time of forming the optical element by means of a liquid drop method. The tapered section can be used for alignment at the time of assembling the light emitting unit, and contributes to process time reduction and prevention of generation of failures.

Abstract: A glass optical element including: a first surface which is formed by transcription of the first transfer surface of the molding die; a second surface which is formed by transcription of the second transfer surface of the molding die and is facing the first surface; and a side surface of the outer periphery formed by transcription of the side transfer surface of the molding die; wherein the glass optical element is characterized by further containing: a first free surface which is formed without contacting with any of the surfaces of the molding die and is connecting the first surface and the side surface of the outer periphery; and a second free surface which is formed without contacting with any of the surfaces of the molding die and is connecting the aforementioned second surface and the side surface of the outer periphery.

Abstract: A glass optical element including: a first surface which is formed by transcription of the first transfer surface of the molding die; a second surface which is formed by transcription of the second transfer surface of the molding die and is facing the first surface; and a side surface of the outer periphery formed by transcription of the side transfer surface of the molding die; wherein the glass optical element is characterized by further containing: a first free surface which is formed without contacting with any of the surfaces of the molding die and is connecting the first surface and the side surface of the outer periphery; and a second free surface which is formed without contacting with any of the surfaces of the molding die and is connecting the aforementioned second surface and the side surface of the outer periphery.

Abstract: A glass material is press-molded by an upper die and a lower die in a closed space, so that an optical element is manufactured. A temperature variation of an atmosphere in the closed space is controlled within ±0.5° C. The glass material is dropped from a nozzle of a fusion furnace onto the lower die. A dropping space between the nozzle and the lower die which receives molten glass droplets is surrounded by an enclosure. Further, a die moving space in which the lower die moves from the dropping position where the molten glass is dropped to a molding position where the upper die stands by is enclosed by another enclosure. The molten glass dropped from the nozzle of the fusion furnace is press-molded in an atmosphere of stable temperature, so that optical glass elements with less variation can be manufactured.