Patent Description:
Passenger aircraft, such as commercial air planes, usually have a passenger cabin comprising a plurality of passenger seats and a plurality of aircraft passenger reading lights. The aircraft passenger reading lights are commonly arranged above the passenger seats, in order to allow passengers, sitting in the passenger seats, to read even if the illumination within the passenger cabin is dimmed low or switched off.

In order to provide a convenient illumination to the passengers, the aircraft passenger reading lights are adapted to the geometry of the passenger cabin of the aircraft in which they are installed and/or adapted to the particulars of the seating zone in which they are installed. The aircraft passenger reading lights are in particular adapted to the spatial distance between the aircraft passenger reading lights and the associated passenger seats. In consequence, different types of aircraft passenger reading lights are installed in different types of aircraft and/or in seating zones with different seating configurations.

Accordingly, it would be beneficial to provide an aircraft passenger reading light which has a wide application range and which may work effectively in different aircraft types and/or different seating configurations.

<CIT> discloses an integrated passenger service unit (PSU) including a housing installable into an aircraft overhead panel and a control knob set into, and positionable relative to, the housing. The housing incorporates signage elements (e.g., fasten seat belts, no smoking) visible through its exterior surface, as well as reading lights and gasper outlets set thereinto. Each reading light includes an LED array selectably configured to illuminate the corresponding seat, and each gasper outlet directs an airstream toward the seat. The housing includes a notification ring configured to illuminate when the passenger calls a flight attendant. A control knob is set within the housing and positionable relative thereto. The control knob incorporates an LCD display and user interface which allows the occupant or passenger to view and adjust the status of the reading lights, gasper outlets, and notification ring.

<CIT> describes a lighting device that has a light source arrangement with a plurality of semiconductor-based light sources in the form of light-emitting diodes. The light sources are bundled or collimated such that they each emit light in differently directed light cones with adjacent light cones overlapping. The lighting device has an adjusting device for adjustment of the direction of illumination and an actuating circuit connected to the adjusting device. The adjusting device adjusts intermediate stages for which the light-emitting diodes of adjacent and overlapping light cones operate and with varying light intensity in such a way the focal point of the light field produced by the light-emitting diodes lies between the focal points of adjacent light cones.

<CIT> discloses a reading light that may be installed above a passenger seat and which has at least one light source, preferably a small halogen or light emitting diode light. A projecting reading light is installed with its optical axis horizontal and whose emitted light beams are deflected into the seating area of an associated passenger seat by an optical deflection arrangement.

According to the invention, the present disclosure provides an aircraft passenger reading light as defined in claim <NUM>. A method of adjusting a light output of an aircraft passenger reading light is disclosed in claim <NUM>. Optional features of the invention are set out in the dependent claims.

Embodiments of the invention include an aircraft passenger reading light that is operable in at least two predetermined configurations and comprises: a housing, a light source configured for providing a light output; an optical element; and an actuation mechanism, which is configured to modify a distance between the light source and the optical element. In an aircraft passenger reading light according to an exemplary embodiments of the invention, the distance between the light source and the optical element differs in the at least two predetermined configurations. In consequence, the light output of the aircraft passenger reading light and, in particular, a spatial extension of the illumination, which results from the light output of the light source and the optical element, differs in the at least two predetermined configurations. The aircraft passenger reading light further comprises at least one longitudinal guide member and at least one corresponding guiding structure, provided at the optical element and/or at a support structure of the light source, for guiding the optical element and/or the support structure of the light source along the at least one longitudinal guide member and for preventing the optical element and/or the light source from rotating. The actuation mechanism includes an actuation member, which is rotatable with respect to the housing. Zhe actuation member is mechanically coupled with the optical element and/or with the light source, such that rotation of the actuation member modifies the distance between the light source and the optical element.

Further in particular, the size / extension of an area, which is illuminated by the light output of the aircraft passenger reading light, when directed onto a plane, which is arranged at a given distance from the aircraft passenger reading light, differs in the at least two predetermined configurations.

As a result, an aircraft passenger reading light according to an exemplary embodiment of the invention may be adapted easily to different geometries of the passenger cabin, in particular to different distances between the aircraft passenger reading light and a passenger seat, which is associated with the aircraft passenger reading light. In consequence, aircraft passenger reading lights according to exemplary embodiments of the invention may be employed easily in different kinds of aircraft, in particular in aircraft in which the geometries of the aircraft passenger cabins are different, and/or in seating zones with different seating configurations. In particular, as compared to previous approaches, less types of aircraft passenger reading lights may be used for equipping different kinds of aircraft and/or for equipping different seating configurations of an aircraft. For example, it is possible that a single type of aircraft passenger reading light in accordance with an exemplary embodiment of the invention is used for passenger seats in an economy class configuration, where an overhead baggage compartment is present and the distance between the aircraft passenger reading light and the passenger seat is comparably small, as well as for passenger seats in a business class configuration, where no overhead baggage compartment is present and the distance between the aircraft passenger reading light and the passenger seat is comparably large.

An aircraft passenger reading light according to an exemplary embodiment of the invention may comprise more than one light source and/or more than one optical element. By employing more than one light source, the total light output provided by the aircraft passenger reading light may be increased. Employing more than one optical element may help to adjust the light output, provided by the aircraft passenger reading light, to the respective needs.

In an embodiment, the light output may be a light cone, and the opening angle of the light output may be different in the at least two predetermined configurations. In consequence, in the at least two predetermined configurations, areas having different sizes will be illuminated at a given distance from the aircraft passenger reading light.

The distance between the light source and the optical element may be modified easily by rotating the actuation member with respect to the housing for changing the light output of the aircraft passenger reading light.

In an embodiment, the rotation of the actuation member causes a linear movement of the optical element and/or of the light source in a longitudinal direction, wherein the axis of rotation of the actuation member may in particular coincide with the longitudinal direction. Changing the distance between the optical element and the light source in a longitudinal direction may change the light output, provided by the aircraft passenger reading light, in a particularly effective manner.

In an embodiment, the actuation member includes a tubular actuation member, and the optical element and/or the light source is/are arranged at least partly within said tubular actuation member. The optical element and/or the light source may be configured to move in a linear manner along the axis of the tubular actuation member. Such a configuration may result in a compact actuation mechanism, which does not considerably increase the space needed for the aircraft passenger reading light.

In an embodiment, the tubular actuation member comprises a circumferential wall and a slot, which is formed within the circumferential wall of the tubular actuation member. The slot may in particular be inclined with respect to the longitudinal direction. A guide member, which is mechanically coupled with the optical element or with the light source, may extend into said slot, causing the guide member to move within the slot, when the tubular actuation member is rotated.

The aircraft passenger reading light further comprises a guiding assembly, which includes at least one longitudinal guide member and at least one corresponding guiding structure, which is provided at the optical element and/or at a support structure of the light source and which may engage with the at least one longitudinal guide member. The guiding assembly may guide the optical element and/or the support structure of the light source linearly along the at least one longitudinal guide member and prevent the optical element and/or the light source from rotating together with the tubular actuation member.

The combination of a slot, which is inclined with respect to the longitudinal direction and which accommodates a guide member that is mechanically coupled with the optical element and/or the light source, and a guiding assembly, which prevents the optical element and/or the light source from rotating, may result in a very effective, robust and space saving actuation mechanism of a bayonet type.

In an embodiment, the guide member is at least partially elastically deformable. The guide member may in particular be elastically deformed, when it is accommodated within the slot. In such a configuration, the guide member may be securely accommodated within the slot. The elasticity of the guide member may in particular avoid any shaky play of the guide member within the slot, which may be caused by tolerances of the dimensions of the slot and/or of the guide member.

The guide member may be at least partially made of an elastic material, and/or it may comprise components, which are elastically mounted to a main body of the guide member. The components may include wing-type elastic extensions or protrusions, which extend from the main body of the guide member.

In an embodiment, at least two dents are formed at different positions along the slot for accommodating the guide member. Each dent may define a predetermined position of the guide member within the slot. Each position may in particular correspond to a respective one of the at least two predetermined configurations of the aircraft passenger reading light. Thus, in such an embodiment, the aircraft passenger reading light may be reliably switched between at least two predetermined configurations by moving the guide member between the different dents, which are formed along the slot. In consequence, the different predetermined configurations of the aircraft passenger reading light may be selected easily and reliably. The dents may prevent the guide member from accidentally moving out of the predetermined position into which it has been moved.

In an embodiment, the tubular actuation member is arranged within the housing, with the tubular actuation member being accessible only from inside the tubular actuation member.

The tubular actuation member and the housing may in particular be configured such that a person, which intends to rotate the tubular actuation member, needs to press his/her fingers against the tubular actuation member from inside the tubular actuation member. Since such a procedure for rotating the tubular actuation member is not obvious / intuitive to persons, who are not authorized and trained for rotating the tubular actuation member, the risk of an accidental and/or unauthorized rotation of the tubular actuation member, in particular the risk of an unauthorized modification of the configuration of the light output of the aircraft passenger reading light, is considerably reduced.

In a further embodiment, a specific tool, which is configured for engaging with the tubular actuation member, may be used or required to be used for rotating the tubular actuation member. In such an embodiment, it is not possible to rotate the tubular actuation member by hand, i.e. without using the specific tool. As a result, the risk of an unauthorized modification of the configuration of the light output of the aircraft passenger reading light may be reduced even further.

In an embodiment, the light source is an LED or the light source includes one or more LEDs. LEDs provide reliable and efficient light sources at low costs. Using a plurality of LEDs may allow increasing the light output provided by the aircraft passenger reading light. Selectively operating a plurality of LEDs, which emit light of different colors, may allow changing the color of the light, which is output by the aircraft passenger reading light.

In an embodiment, the optical element includes at least one lens. The optical element may in particular include at least one Fresnel lens. A lens, in particular a Fresnel lens, may be a very effective optical element for transforming the light emission, which is provided by the light source, into the desired light output. A lens / Fresnel lens may allow for forming a light output, in particular a light beam, which has a defined opening angle. Alternatively or additionally, the optical element may comprise one or more reflectors and/or one or more shutters.

Exemplary embodiments of the invention also include a passenger service unit, in particular an overhead passenger service unit, which may be arranged over one or more passengers seats within a passenger cabin of an aircraft. The passenger service unit comprises at least one aircraft passenger reading light according to an exemplary embodiment of the invention. Such passenger service units may be installed in different types of aircraft, in particular in different types of aircraft, in which the distances between the aircraft passenger reading lights and the associated passenger seats differ. The light output provided by the at least one aircraft passenger reading light, which is installed within the passenger service unit, may be easily adapted to the different distances between the aircraft passenger reading lights and the associated passenger seats. Also, when the passenger service unit is re-located from a first kind of seating configuration, such as a seating configuration with overhead baggage compartments, to a second kind of seating configuration, such as a seating configuration without overhead baggage compartments, the at least one aircraft passenger reading light may be conveniently adapted to the altered geometry of the seating configuration. The additional features, modification and effects, described above with respect to the aircraft passenger reading light, apply to the passenger service unit in an analogous manner.

Exemplary embodiments of the invention further include an aircraft, such as an air plane or a helicopter, which comprises at least one aircraft passenger reading light according to an exemplary embodiment of the invention and/or at least one passenger service unit according to an exemplary embodiment of the invention. The additional features, modification and effects, described above with respect to the aircraft passenger reading light, apply to the aircraft in an analogous manner.

Exemplary embodiments of the invention also include a method of adjusting a light output of an aircraft passenger reading light according to an exemplary embodiment of the invention, wherein the method includes changing the distance between the optical element and the light source from a first predetermined distance to a second predetermined distance via the actuation mechanism. The method may in particular include changing the distance between the optical element and the light source from the first predetermined distance to the second predetermined distance by rotating the actuation member with respect to the housing.

According to an embodiment, the first and second predetermined distances are defined by the mechanical structure of the aircraft passenger reading light.

In an embodiment, the method includes employing a specific tool, which is configured for engaging with the tubular actuation member, for rotating the tubular actuation member. Such a tool may facilitate the rotation of the tubular actuation member. It may in particular not be possible to rotate the tubular actuation member without using the specific tool or a similar device. In such an embodiment, an unauthorized modification of the configuration of the light output of the aircraft passenger reading light may be prevented very reliably.

Exemplary embodiments of the invention further include a method of adjusting the light output of at least one aircraft passenger reading light. The method may in particular include adjusting the light output of a plurality of aircraft passenger reading lights within a passenger cabin of an aircraft as part of a re-configuration of the seating map within the passenger cabin or as part of relocating the reading lights and/or passenger service units within the passenger cabin.

Relocating the aircraft passenger reading lights and/or passenger service units within the passenger cabin may in particular be part of a re-configuration of at least a portion of the passenger cabin of the aircraft from a business class configuration, in which there a no overhead baggage bins, to an economy class configuration, in which overhead baggage bins are installed over the passenger seats, or vice versa.

Relocating the aircraft passenger reading lights and/or passenger service units may include moving the aircraft passenger reading lights and/or passenger service units from a business class section of the passenger cabin of the aircraft to an economy class section of the passenger cabin, or vice versa.

Further exemplary embodiments of the invention are described below with respect to the accompanying drawings, wherein:.

<FIG> depicts a schematic side view of an aircraft <NUM>, in particular of an air plane, in accordance with an exemplary embodiment of the invention. In the exemplary embodiment shown in <FIG>, the aircraft <NUM> is a large passenger air plane comprising a cockpit <NUM> and a passenger cabin <NUM>. The aircraft <NUM> may be a commercial passenger air plane, a private air plane, or a military aircraft. It is also possible that a passenger reading light according to an exemplary embodiment of the invention is implemented in a rotorcraft, such as a helicopter.

<FIG> shows a schematic longitudinal cross-sectional view of a section of the passenger cabin <NUM> of the aircraft <NUM> shown in <FIG>.

Four seats <NUM>, also referred to as passenger seats <NUM>, are shown in <FIG>. The passenger seats <NUM> are mounted to the floor <NUM> of the passenger cabin <NUM>. Each of the depicted passenger seats <NUM> belongs to a different seat row.

For each of the seat rows, a window <NUM> is provided, which allows the passengers to view the outside of the aircraft <NUM>. Further, a plurality of overhead baggage compartments <NUM> are shown. The overhead baggage compartments <NUM> provide storage space for the passengers' baggage.

Each seat row includes a plurality, for example two or three, passenger seats <NUM>, which are arranged next to each other, perpendicular to the viewing plane of <FIG>. The additional passenger seats <NUM> of each seat row are not visible in <FIG>, as they are arranged behind and therefore hidden by the depicted first passenger seats (aisle seats) <NUM> of each seat row.

Passenger service units ("PSUs") <NUM> comprising aircraft passenger reading lights <NUM> according to exemplary embodiments of the invention are provided above the passenger seats <NUM>. Details of the passenger service units <NUM> will be discussed further below with reference to <FIG>.

Usually, a single aircraft passenger reading light <NUM> is associated with each of the passenger seats <NUM>, respectively. In particular, each aircraft passenger reading light <NUM> may be associated with one of the passenger seats <NUM> and may be configured for emitting a light output <NUM> towards the associated passenger seat <NUM>.

The light outputs <NUM> of the aircraft passenger reading lights <NUM> may be configured for providing sufficient illumination to each passenger seat <NUM>, without providing unnecessary illumination of neighboring passenger seats <NUM>.

In consequence, the specifics of the light output <NUM>, in particular an opening angle α of a light cone, which is output by each aircraft passenger reading light <NUM>, may depend on the distance between the aircraft passenger reading light <NUM> and the associated passenger seat <NUM>. A smaller distance between the aircraft passenger reading light <NUM> and the associated passenger seat <NUM> may be dealt with via a larger opening angle α of the light output <NUM>, and vice versa.

In order to allow for employing the same type of aircraft passenger reading lights <NUM> in different passenger cabins <NUM>, in particular in passenger cabins <NUM> having different geometries and seat configurations, which result in different distances between the aircraft passenger reading lights <NUM> and the respectively associated passenger seats <NUM>, it may be desirable that the light outputs <NUM>, provided by the aircraft passenger reading lights <NUM>, are adjustable to different distances between the aircraft passenger reading lights <NUM> and the respectively associated passenger seats <NUM>.

<FIG> depicts a schematic view of an overhead passenger service unit ("PSU") <NUM> according to an exemplary embodiment of the invention, which may be arranged above the passenger seats <NUM> of a single seat row, as it is shown in <FIG>.

<FIG> depicts the overhead passenger service unit <NUM>, as it is seen by a passenger sitting on a passenger seat <NUM> below the overhead passenger service unit <NUM>.

On the side that is shown to the left in <FIG>, the overhead passenger service unit <NUM> comprises a row of three adjustable aircraft passenger reading lights <NUM>, which are arranged next to each other.

Six electrical switches <NUM>, <NUM> are provided to the right side of the aircraft passenger reading lights <NUM>, a respective pair of two switches <NUM>, <NUM> next to each of the aircraft passenger reading lights <NUM>. A first one of the switches <NUM> of each pair is configured for switching the adjacent aircraft passenger reading light <NUM> on and off, and the second switch <NUM> of each pair is configured for triggering a signal for calling cabin service personnel.

A row of three adjacent gaspers <NUM> is provided next to the switches <NUM>, <NUM>.

Adjacent to the gaspers <NUM>, there is a movable door <NUM>, which covers a compartment housing at least three oxygen masks. The compartment and the oxygen masks are not visible in <FIG>, as they are covered by the movable door <NUM>.

In the event of pressure loss within the passenger cabin <NUM>, the movable door <NUM> will open, allowing the oxygen masks to drop out of the compartment. Each of the passengers sitting on a passenger seat <NUM> below the overhead passenger service unit <NUM> may grasp one of the oxygen masks. After being activated, an oxygen generator, which is not shown in the figures, will supply the oxygen masks with oxygen.

On the side opposite to the gaspers <NUM>, a grid <NUM> is formed within the overhead passenger service unit <NUM>. A loudspeaker (not shown), which may be used for delivering acoustic announcements to the passengers, may be arranged behind said grid <NUM>.

Next to the grid <NUM>, there is a display panel <NUM>, which may be configured for selectively showing a plurality of visual signs (not shown), such as "non smoking" or "fasten your seat belt". The display panel <NUM> may be illuminated from behind, in order to deliver visual information to the passengers sitting on the passenger seats <NUM> below the overhead passenger service unit <NUM>.

An exemplary embodiment of an aircraft passenger reading light <NUM>, which allows adjusting its light output <NUM> to different distances between the aircraft passenger reading light <NUM> and the respectively associated passenger seat <NUM>, will be described in the following with reference to <FIG>.

<FIG> depicts a cross-sectional view through an aircraft passenger reading light <NUM> according to the invention.

The aircraft passenger reading light <NUM> comprises a housing <NUM>, which includes two housing elements 4a, 4b, namely an upper housing element 4a and a lower housing element 4b. The upper and lower housing elements 4a, 4b are joined at an interface <NUM>. The housing <NUM> has a ball-like shape, with a substantially spherical upper portion <NUM> and a tubular portion <NUM>, extending from a lower end of the substantially spherical upper portion <NUM>. The substantially spherical upper portion <NUM> of the housing <NUM> may be spherical, but it may also have another round / rounded shape, which does not need to be exactly spherical.

A light source support structure <NUM>, which may be a light source support board <NUM>, in particular a printed circuit board (PCB), is arranged within the housing <NUM>. The light source support structure <NUM> supports a light source <NUM>. The light source <NUM> may be an LED, or it may comprise at least one LED. The light source <NUM> may in particular comprise a plurality of LEDs.

The tubular portion <NUM> of the housing <NUM> comprises an outer portion 8a, which extends outwards from the substantially spherical upper portion <NUM> of the housing <NUM>, and an inner portion 8b, which extends inwards towards the center of the housing <NUM>. The outer portion 8a and the inner portion 8b are rotationally symmetric with respect to a common axis A.

In the embodiment depicted in the Figures, the diameter of the inner portion 8b of the tubular portion <NUM> is larger than the diameter of the outer portion 8a of the tubular portion <NUM>. An inclined portion 8c connects the outer portion 8a with the inner portion 8b.

The diameter of the inner portion 8b of the tubular portion <NUM> may be in the range from <NUM> to <NUM>, in particular in the range from <NUM> to <NUM>, and the diameter of the outer portion 8a of the tubular portion <NUM> may be in the range from <NUM> to <NUM>, in particular in the range from <NUM> to <NUM>.

A tubular actuation member <NUM> is arranged within the tubular portion <NUM> of the housing <NUM>. The tubular actuation member <NUM> is in particular arranged co-axially with the tubular portion <NUM> around the common axis A.

Similar to the tubular portion <NUM>, the tubular actuation member <NUM> comprises an outer portion 14a, which is co-axially arranged within the outer portion 8a of the tubular portion <NUM>, and an inner portion 14b, which is co-axially arranged within the inner portion 8b of the tubular portion <NUM>. The inner portion 14b of the tubular actuation member <NUM> has a larger diameter than the outer portion 14a of the tubular actuation member <NUM>.

An inclined portion 14c is formed between the inner and outer portions 14a, 14b of the tubular actuation member <NUM>. The inclined portion 14c of the tubular actuation member <NUM> may extend along and about against the inclined portion 8c of the tubular portion <NUM>.

The tubular actuation member <NUM> is rotatable with respect to the tubular portion <NUM> around the common axis A.

Any outward movement of the tubular actuation member <NUM> with respect to the tubular portion <NUM> along the axis A is prevented by the inclined portion 8c of the tubular portion <NUM>, which abuts against the inclined portion 14c the tubular actuation member <NUM>. Any inward movement of the tubular actuation member <NUM> with respect to the tubular portion <NUM> is prevented by at least one latch 8d, which is formed at an upper end of the inner portion 8b of the tubular portion <NUM>. The at least one latch 8d engages with an inner end <NUM> of the inner portion 14b of the tubular actuation member <NUM>.

Although only one latch 8d is visible in the cross-sectional view depicted in <FIG>, the aircraft passenger reading light <NUM> may comprise a plurality of latches 8d, for example three latches 8d, which are arranged along the circumference of the inner portion 8b of the tubular portion <NUM> for reliably preventing any linear inward movement of the tubular actuation member <NUM> along the axis A. The latches 8d may be arranged with constant angular distances between adjacent latches 8d. In the case of three latches 8d, the angular distances between two adjacent latches 8d may in particular be <NUM>°.

The outer portion 14a of the tubular actuation member <NUM> supports a light transmissive element <NUM>, for example a cover lens <NUM>, which is attached to the outer portion 14a of the tubular actuation member <NUM>.

An optical element <NUM>, in particular a lens <NUM>, more particularly a Fresnel lens <NUM>, is arranged within the upper portion 14b of the tubular actuation member <NUM>. The optical element <NUM> may in particular have rotational symmetry with respect to the axis A.

The optical element <NUM> is linearly movable along the axis A by rotating the tubular actuation member <NUM> around the axis A. The rotating motion of the tubular actuation member <NUM> allows for varying the distance D between the optical element <NUM> and the light source <NUM>, which is arranged stationary within the housing <NUM>.

The distance D may in particular be changed within a range from <NUM> to <NUM>, in particular within a range from <NUM> to <NUM>. These values do not mean that all distances D between the lower and upper limit values have to be possible, i.e. that the whole range has to be covered by the different distances D. Rather, the given range is intended to indicate that the distances associated with the predetermined configurations of the aircraft passenger reading light are somewhere within the given range.

Varying the distance D between the optical element <NUM> and the light source <NUM> modifies the light output <NUM>, which is emitted by the aircraft passenger reading light <NUM>. Changing the distance D between the optical element <NUM> and the light source <NUM> may in particular allow for modifying the opening angle α of the light output <NUM>.

In the following, a mechanical actuation mechanism <NUM>, which allows for moving the optical element <NUM> along the axis A by rotating the tubular actuation member <NUM> and which is plemented in aircraft passenger reading lights in accordance with the invention, will be described.

<FIG> depicts a side view of the actuation mechanism <NUM>, with the housing <NUM> being removed. <FIG> depicts a perspective view of the inner structure of the actuation mechanism <NUM>, with the tubular actuation member <NUM>, which is part of the actuation mechanism <NUM>, being removed as well.

A plurality of longitudinal guide members <NUM>, which may be provided as substantially cylindrical posts, extend orthogonally from the light source support board <NUM>. The exemplary embodiment depicted in the Figures comprises three longitudinal guide members <NUM>, which are arranged at equal angular distances of <NUM>° between each other around the axis A. Embodiments comprising more or less than three longitudinal guide members <NUM> are possible as well.

Guiding structures <NUM>, which correspond to the longitudinal guide members <NUM> are formed at the outer periphery of the optical element <NUM>. The optical element <NUM> is in particular provided with three guiding structures <NUM>. Each guiding structure <NUM> engages with a corresponding longitudinal guide member <NUM>, forming a respective guiding assembly <NUM>, <NUM>. In case the aircraft passenger reading light <NUM> comprises more or less than three longitudinal guide members <NUM>, the number of guiding structures <NUM> formed at the outer periphery of the optical element <NUM> is adjusted accordingly.

In the exemplary embodiment depicted in the Figures, each guiding structure <NUM> includes two guiding elements 22a, 22b, which are formed at the outer periphery of the optical element <NUM> so that a gap is formed between the two guiding elements 22a, 22b. One of the longitudinal guide members <NUM> extends though the gap formed between the two guiding elements 22a, 22b, respectively. As the longitudinal guide members <NUM> are fixed to the light source support board <NUM>, the mechanical interaction between the longitudinal guide members <NUM> and the guiding structures <NUM> prevents a rotation of the optical element <NUM> with respect to the the light source support structure <NUM> around the axis A.

In addition to the guiding structures <NUM>, at least one guide member <NUM> is formed at the outer periphery of the optical element <NUM>. In the exemplary embodiment depicted in the Figures, each of the guide membesr <NUM> comprises a cylindrical protrusion <NUM>, which extends outwards from the outer periphery of the optical element <NUM> in a radial direction. Two wing-like extensions 28a, 28b are formed at the cylindrical protrusion <NUM>. The wing-like extensions 28a, 28b are elastic and extend substantially perpendicular to the radial direction of the cylindrical protrusion <NUM>.

As shown in <FIG>, at least one slot <NUM> is formed within the circumferential wall of the inner portion 14b of the tubular actuation member <NUM>. The at least one slot <NUM> is formed in an inclined orientation with respect to the axis A of the tubular actuation member <NUM>. The at least one slot <NUM> may in particular be inclined at an angle β in the range of between <NUM>° and <NUM>°, further in particular at an angle β of <NUM>°, with respect to the axis A.

The guide member <NUM> extends into said slot <NUM>. Since the optical element <NUM>, and in consequence also the guide member <NUM>, are prevented from rotating around the axis A due to the interaction of the guiding structures <NUM> with the longitudinal guide members <NUM>, the slot <NUM> moves relative to the guide member <NUM>, when the tubular actuation member <NUM> is rotated around the axis A. Due to the inclination of the slot <NUM>, the relative movement between the guide member <NUM> and the slot <NUM> generates a longitudinal motion of the tubular actuation member <NUM>, i.e. a motion of the tubular actuation member <NUM> along the axis A. In the orientation of the aircraft passenger reading light <NUM> shown in the Figures, this motion is a vertical motion. In consequence, the optical element <NUM> is moved along the axis A, when the tubular actuation member <NUM> is rotated around the axis A.

As a result, the distance D between the optical element <NUM> and the light source <NUM> is variable by rotating the tubular actuation member <NUM> around its axis A. Thus, the actuation mechanism <NUM> is of a bayonet type, in which a rotational movement of the tubular actuation member <NUM> is transferred into a linear movement of the optical element <NUM>.

A person that intends to rotate the tubular actuation member <NUM> for adjusting the distance D between the optical element <NUM> and the light source <NUM> may press his/ her fingers against the outer portion 14a of the tubular actuation member <NUM> from inside the tubular actuation member <NUM> and may then rotate the tubular actuation member <NUM>. As this procedure for rotating the tubular actuation member <NUM> is not obvious / intuitive to persons, who are not authorized and trained for rotating the tubular actuation member <NUM>, the risk that the tubular actuation member <NUM> is rotated accidentally and/or in an unauthorized manner is very low.

In order to reduce the risk of an unauthorized rotation of the tubular actuation member <NUM> even further, the outer portion 14a of the tubular actuation member <NUM> may be configured such that it is rotatable only with a specific tool, which is given only to authorized personnel.

By varying the distance between the optical element <NUM> and the light source <NUM>, the properties of the light output <NUM>, which is emitted by the aircraft passenger reading light <NUM>, is modified.

As it is illustrated in <FIG>, modifying the properties of the light output <NUM> may allow for changing the size S of an area F, which is illuminated by the light output <NUM>, at a given distance from the aircraft passenger reading light <NUM>. Stated differently, modifying the light output <NUM> may result in keeping the size S of an area F substantially constant, when changing the distance a<NUM>, a<NUM>, a<NUM> between the aircraft passenger reading light <NUM> and an illumination plane P.

The illustration, which is given in <FIG>, is simplified for illustrative purposes. Usually, the illuminated area F does not have a sharp outer edge. Thus, the size S of the area F is defined as the size S of the portion of the plane P, which is illuminated by the aircraft passenger reading light <NUM> to at least a predefined brightness, i.e. to a brightness, which has been set to a predefined value. Said predefined value may, for example, be selected from in between <NUM> Ix and <NUM> lx, in particular from in between <NUM> Ix and <NUM> Ix.

In other words, the outer peripheral boundary of the illuminated area F may be defined so that the brightness outside said boundary is below the predefined value and that the brightness inside said boundary is above the predefined value.

The illuminated area F, which is defined by said boundary, may be substantially circular having a diameter S, which may be in the range of between <NUM> and <NUM>, in particular in the range of between <NUM> and <NUM>.

The illuminated area F does not need to have a circular shape. The illuminated area F may also have an elliptical shape or a shape, which is similar to an elliptical shape, wherein the length of the major axis and the length of the minor axis are in the range of between <NUM> and <NUM>, in particular in the range of between <NUM> and <NUM>, respectively. Other shapes of the illuminated area F are possible as well.

Three different light outputs <NUM> of the aircraft passenger reading light <NUM>, which correspond to three different distances D between the optical element <NUM> and the light source <NUM>, are schematically illustrated in <FIG>.

Although in <FIG> the plane P is arranged in three different distances a<NUM>, a<NUM>, a<NUM> from the aircraft passenger reading light <NUM>, the size S of the area F, which is illuminated by the light output <NUM>, is similar or identical in all three configurations.

Thus, the properties of the light output <NUM>, which is emitted by the aircraft passenger reading light <NUM>, may be adjusted to different distances a<NUM>, a<NUM>, a<NUM> between the aircraft passenger reading light <NUM> and a corresponding passenger seat <NUM>. In consequence, the same aircraft passenger reading light <NUM> may be used for different seating configurations in an aircraft passenger cabin <NUM> and in different aircraft passenger cabins <NUM>.

The distances a<NUM>, a<NUM>, a<NUM> between the aircraft passenger reading light <NUM> and the plane P may be in the range of between <NUM> and <NUM>, in particular in the range of between <NUM> and <NUM>, more particularly in the range of between <NUM> and <NUM>.

<FIG> further shows that a plurality of dents 32a, 32b, 32c are formed at different positions along the lower edge of the slot <NUM>. The dents 32a, 32b, 32c are configured for accommodating the guide member <NUM>. By accommodating the guide member <NUM>, the dents 32a, 32b, 32c define predetermined positions of the guide member <NUM> within the slot <NUM>. Each position of the guide member <NUM> corresponds to a predefined distance D between the optical element <NUM> and the light source <NUM>, which in turn corresponds to a predetermined light output <NUM>, as it has been described before.

Each position of the guide member <NUM> within the slot <NUM> and the corresponding light output <NUM> are associated with a predefined distance a<NUM>, a<NUM>, a<NUM> between the aircraft passenger reading light <NUM> and the passenger seat <NUM>, which is associated with the respective aircraft passenger reading light <NUM>.

The elastic extensions 28a, 28b, formed at the cylindrical protrusion <NUM> of the guide member <NUM>, elastically abut against the opposing edge of the slot <NUM>, thereby pressing the cylindrical protrusion <NUM> elastically into the respective dent 32a, 32b, 32c.

In consequence, when the tubular actuation member <NUM> is arranged in one of the predefined rotational positions, in which the guide member <NUM> is accommodated in one of the dents 32a, 32b, 32c, a larger force needs to be applied for rotating the tubular actuation member <NUM> and moving the guide member <NUM> out of the respective dent 32a, 32b, 32c. Similarly, there is a tactile feedback to a person rotating the tubular actuation member <NUM>, when the guide member "drops" into one of the dents 32a, 32b, 32c.

As a result, the distance D between the optical element <NUM> and the light source <NUM> may be modified easily and reliably between the predefined positions, which are defined by the dents 32a, 32b, 32c. Further, accommodating the guide member <NUM> within the dents 32a, 32b, 32c helps in reliably preventing an accidental movement of the tubular actuation member <NUM>, which would result in an undesired modification of the optical properties of the light output <NUM> provided by the aircraft passenger reading light <NUM>.

In the exemplary embodiment depicted in the Figures, the dents 32a, 32b, 32c are formed in a "lower" edge of the slot <NUM>, i.e. in the edge of the slot <NUM> arranged on the side of the slot <NUM> facing the light output side of the aircraft passenger reading light <NUM>, and the elastic extensions 28a, 28b are configured to abut against the opposing "upper" edge of the slot <NUM>, i.e. against the edge of the slot <NUM> arranged on the side of the slot <NUM> facing the light source <NUM>.

In an alternative configuration, which is not explicitly shown in the figures, the dents 32a, 32b, 32c may be formed in the "upper" edge of the slot <NUM>, and the elastic extensions 28a, 28b may be configured to abut against the opposing "lower" edge of the slot <NUM>.

The exemplary embodiment depicted in <FIG> comprises three dents 32a, 32b, 32c, which correspond to three different distances between the optical element <NUM> and the light source <NUM>. Depending on the intended field of use of the aircraft passenger reading light <NUM>, more or less than three dents 32a, 32b, 32c may be formed within the edge of the slot <NUM>, in order to define more or less than three different optical configurations of the aircraft passenger reading light <NUM>.

Only a single slot <NUM>, which is formed within the tubular actuation member <NUM>, and a single guide member <NUM>, which is formed at the outer periphery of the optical element <NUM> and which extends into said slot <NUM>, are visible in <FIG>.

In order to ensure a well-defined linear movement of the light source support board <NUM>, in particular in order to reliably prevent any tilting of the light source support board <NUM>, a plurality of slots <NUM> may be formed within the tubular actuation member <NUM>. Correspondingly, a plurality of guide members <NUM>, extending into said slots <NUM>, may extend from the outer periphery of the optical element <NUM>.

In particular, three identical slots <NUM>, which may be formed at angular distances of <NUM>° with respect to each other, may be formed within the peripheral wall of the tubular actuation member <NUM>. Correspondingly, three guide members <NUM>, which may in particular be formed at angular distances of <NUM>° with respect to each other, may be provided at the outer circumference of the optical element <NUM>. A configuration comprising three slots <NUM> and three corresponding guide members <NUM>, wherein each of the three guide members <NUM> extends in one of the three slots <NUM>, may result in a well-defined linear movement of the optical element <NUM>. It may in particular prevent an undesired tiling or wiggling of the optical element <NUM> in a reliable manner.

Forming more than three slots <NUM> and more then three guide member <NUM>, extending into said slots <NUM>, could result in an over-determination of the spatial position and orientation of the optical element <NUM>.

<FIG> depicts a perspective view of selected components of an aircraft passenger reading light in accordance with an exemplary embodiment of the invention from the light output side. The housing <NUM> and the tubular actuation member <NUM> have been removed for ease of view of the optical element <NUM> and its guiding components. <FIG> shows that three guide members <NUM> are provided on the outer circumference of the optical element <NUM>. The three guide members <NUM> are spaced apart at angles of <NUM>° from each other.

<FIG> further shows three guiding structures <NUM>, which are also spaced apart at angles of <NUM>° from each other along the outer circumference of the the optical element <NUM>. Each guiding structure <NUM> engages with a corresponding longitudinal guide member <NUM>, which extends orthogonally from the light source support board <NUM>.

<FIG> depicts a perspective view into the lower housing element 4b of the housing <NUM> of an aircraft passenger reading light in accordance with an exemplary embodiment of the invention, with the upper housing element 4a being removed. In particular, <FIG> shows the tubular actuation member <NUM>, which is arranged within the tubular portion <NUM> of the lower housing element 4b, and three latches 8d, which are formed at the upper end of the inner portion 8b of the tubular portion <NUM>, in order to prevent the tubular actuation member <NUM> from moving upwards with respect to the tubular portion <NUM>.

The movable optical element <NUM> is arranged within the tubular actuation member <NUM>. One of the three slots <NUM>, formed within the tubular actuation member <NUM>, is visible in <FIG>. The second and third slots <NUM> are not visible in <FIG> as they are covered by the tubular actuation member <NUM> and the tubular portion <NUM>.

Three channels <NUM>, which are also spaced apart from each other at <NUM>°, are formed within the circumferential wall of the tubular actuation member <NUM>. Each channel <NUM> is configured for accommodating a respective one of the longitudinal guide members <NUM> (cf.

In the exemplary embodiment depicted in the Figures, the light source <NUM> remains stationary with respect to the housing <NUM>, and the optical element <NUM> is movable with respect to the housing <NUM> and, thus, with respect to the at least one stationary light source <NUM>.

In an alternative embodiment, which is not explicitly depicted in the Figures, the roles of the optical element <NUM> and the light source <NUM> may be exchanged, i.e. the optical element <NUM> may be stationary with respect to the housing <NUM> and the light source support board <NUM>, which supports the light source <NUM>, may be movable with respect to the optical element <NUM>, in order to modify the distance D between the light source <NUM> and the optical element <NUM>.

Configurations in which both the light source <NUM> and the optical element <NUM> are movable with respect to the housing <NUM>, preferably in opposite directions, are possible as well.

In such a configuration, the tubular actuation member <NUM> may comprise a first group of slots, which are configured for moving the optical element <NUM>, as it has been described before, and a second group of slots, which are inclined in an opposite manner as compared to the first group of slots and which are configured for interacting with the light source support structure <NUM> for moving the light source <NUM>.

An aircraft passenger reading light according to an exemplary embodiment of the invention may also comprise a plurality of optical elements <NUM>, which are movable collectively or individually with respect to the light source <NUM>.

While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made without departing from the scope of the invention, as defined by the appended claims.

Claim 1:
Aircraft passenger reading light (<NUM>), which is operable in at least two predetermined configurations, the aircraft passenger reading light (<NUM>) comprising:
a housing (<NUM>);
a light source (<NUM>), configured for providing a light output (<NUM>);
an optical element (<NUM>); and
an actuation mechanism (<NUM>), which is configured to modify a distance between the light source (<NUM>) and the optical element (<NUM>);
wherein the distance (D) between the light source (<NUM>) and the optical element (<NUM>) differs in the at least two predetermined configurations and wherein a spatial extension (S) of the illumination, which results from the light output (<NUM>) of the light source (<NUM>) and the optical element (<NUM>), differs in the at least two predetermined configurations;
characterized in that the aircraft passenger reading light (<NUM>) further comprises: a support structure (<NUM>) of the light source (<NUM>); and
at least one longitudinal guide member (<NUM>); and
at least one corresponding guiding structure (<NUM>), provided at the optical element (<NUM>) and/or at the support structure (<NUM>) of the light source (<NUM>), for guiding the optical element (<NUM>) and/or the support structure (<NUM>) of the light source (<NUM>) along the at least one longitudinal guide member (<NUM>) and for preventing the optical element (<NUM>) and/or the light source (<NUM>) from rotating; and in that
the actuation mechanism (<NUM>) includes an actuation member (<NUM>), which is rotatable with respect to the housing (<NUM>);
wherein the actuation member (<NUM>) is mechanically coupled with the optical element (<NUM>) and/or with the light source (<NUM>), such that rotation of the actuation member (<NUM>) modifies the distance between the light source (<NUM>) and the optical element (<NUM>).