Abstract: The invention relates to a protective helmet with an outer shell (1) for distributing impact forces, an interior layer (2) accommodated by the outer shell (1) for attenuating impact forces, and a slot (3) for accommodating an electrical device (4), wherein the outer shell (1) has a chin shell area (6) to cover a chin portion of a protective helmet wearer, wherein the outer shell (1) forms a viewing port (8) for the protective helmet wearer to look through. The protective helmet is characterized in that the slot (3) is arranged on the chin shell area (6) in such a way that the accommodated electrical device (4) is arranged between the chin shell area (6) and the interior layer (2), wherein the protective helmet has an interior cover (10) for essentially completely covering the accommodated electrical device (4) in the direction of the viewing port (8).

Abstract: A projection arrangement includes a composite pane including transparent outer and inner panes, a thermoplastic intermediate layer, and a reflection layer, the outer pane having an outer side facing away from the thermoplastic intermediate layer and an inner side facing the thermoplastic intermediate layer and the inner pane has an outer side facing the thermoplastic intermediate layer and an inner side facing away from the thermoplastic intermediate layer, the reflection layer being arranged between the outer and inner panes and reflecting p-polarized light, the reflection layer being opaque or arranged spatially in front of an opaque background when viewed through the composite pane, and an image display device directed at the reflection layer and irradiates it with p-polarized light through the inner pane, wherein the reflection layer reflects the p-polarized light.

Abstract: A reflector emitter includes a combination reflector having at least one elliptical concave mirror shaped as an ellipsoid of revolution section having first and second focal points disposed outside and inside of the ellipsoid of revolution section, respectively. The reflector emitter includes at least one light source at the second focal point. The ellipsoid of revolution section is formed as an ellipsoid of revolution that is cut between its center and the first focal point in a longitudinal section plane and in a cross-sectional plane. An aperture is provided above an other concave mirror having at least one focal point that coincides with the first focal point of the ellipsoid of revolution section. The other concave mirror is formed as a hollow body cut in a sectional plane through its focal point. This sectional plane and the longitudinal section plane of the ellipsoid of revolution section share a common plane of reference and the concave mirrors have opposing faces.

Abstract: A ring lamp includes a light source having a first hollow cylinder with a lighting device disposed therein. The light source has an emitting surface with a light-emitting direction oriented toward an axis of the hollow cylinder. The lamp also includes a light directing device configured to direct light emission. The light directing device includes a lens system having a lens formed as a second hollow cylinder and configured to focus light into a radial plane which is orthogonal to the axis. The lens system has a ring-shaped aperture diaphragm disposed centrally in an optical path of the light emission behind the lens. The emitting surface of the light source and the lens system have a same length, are coaxial and axially aligned with each other. A radial surface which is defined by an inner radius of the lens system and the length of the lens system spans a delimited volume.

Abstract: A reflector emitter includes a combination reflector having at least one elliptical concave mirror shaped as an ellipsoid of revolution section having first and second focal points disposed outside and inside of the ellipsoid of revolution section, respectively. The reflector emitter includes at least one light source at the second focal point. The ellipsoid of revolution section is formed as an ellipsoid of revolution that is cut between its center and the first focal point in a longitudinal section plane and in a cross-sectional plane. An aperture is provided above an other concave mirror having at least one focal point that coincides with the first focal point of the ellipsoid of revolution section. The other concave mirror is formed as a hollow body cut in a sectional plane through its focal point. This sectional plane and the longitudinal section plane of the ellipsoid of revolution section share a common plane of reference and the concave mirrors have opposing faces.

Abstract: A ring lamp includes a light source having a first hollow cylinder with a lighting device disposed therein. The light source has an emitting surface with a light-emitting direction oriented toward an axis of the hollow cylinder. The lamp also includes a light directing device configured to direct light emission. The light directing device includes a lens system having a lens formed as a second hollow cylinder and configured to focus light into a radial plane which is orthogonal to the axis. The lens system has a ring-shaped aperture diaphragm disposed centrally in an optical path of the light emission behind the lens. The emitting surface of the light source and the lens system have a same length, are coaxial and axially aligned with each other. A radial surface which is defined by an inner radius of the lens system and the length of the lens system spans a delimited volume.

Abstract: A method of establishing a community including a first mobile communication device user and a second mobile communication device user is disclosed. The method includes receiving a first message from the first mobile communication device user and receiving a second message from the second mobile communication device user. The method further includes parsing the first message and the second message to determine a first user identifier and a first user-generated key and a second user identifier and a second user-generated key respectively. Furthermore, the method includes calculating a matching probability between the first mobile communication device user and the second mobile communication device user based on at least one of a proximity of distance, a proximity of time of the receipt of messages, and matching of the user-generated keys.