Abstract:
A passenger seat includes a first seat element and at least one second seat chamber element that are movable relative to each other, and which can be stood on a base of a transport means and has at least one optical transmission unit having a light input element, at least one light output element and at least one light guide path that runs from the light input element to the light output element and along which light is conducted. The optical transmission unit is provided for contact-free transmission of light in at least one operating state at at least one location of the light guide path that differs from a location of a light input into the light input element and from a location of light output from the light output element.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a U.S. national stage application of PCT/EP2011/004181 filed on Aug. 19, 2011, and claims priority to, and incorporates by reference German Patent Application No. 10 2010 035 415.5 filed on Aug. 25, 2010. 
     BACKGROUND 
     The invention is based on a passenger seat which has a first seat element and at least a second seat element which are movable relative to one another, and which passenger seat can be stood on a floor of a means of transportation and has at least one optical transmission unit. 
     Such a passenger seat which has a transmission unit for transmitting light from the first seat element to the second seat element is already known. 
     SUMMARY 
     The invention is based on the object of making available a passenger seat of a generic type by means of which the reliability of the transmission of light between seat elements can be increased. 
     This object is achieved by means of a passenger seat as discussed below. 
     The invention is based on a passenger seat which has a first seat element and at least a second seat element which are movable relative to one another, and which passenger seat can be stood on a floor of a means of transportation. The seat elements can be embodied, for example, as a seat bottom on which a passenger sits, as the backrest which supports the back part of the passenger, as a seat housing element or as an armrest. The passenger seat can also have further seat elements which are known to a person skilled in the art. 
     The first seat element and the second seat element are movable relative to one another in a normal operating mode of the passenger seat. However, in principle, in the normal operating mode of the passenger seat said first seat element and second seat element can also be arranged fixedly relative to one another and be movable relative to one another only in at least one other operating mode of the passenger seat which is different from the normal operating mode. Such an operating mode which is different from the normal operating made may be, for example, a maintenance mode of the passenger seat. 
     It is proposed that the passenger seat has at least one optical transmission unit having a light input element, at least one light output element and at least one light guide path which runs from the light input element to the light output element and along which light is guided, wherein the optical transmission unit is provided for transmitting light in a contactless fashion in at least one operating state, at at least one location of the light guide path which differs from a location of a light input into the light input element and from a location of a light output from the light output element. A “light input element” is to be understood in this context as meaning, in particular, an element of the optical transmission unit, at which light which is generated by a light source enters the light guide path. “Contactless transmission of light” is to be understood in this context as meaning, in particular, that the light guide path has at least one region in which, apart from the air which is present on all sides, no other material, in particular no solid, is arranged. 
     In a corresponding configuration, a solution for transmission of light can be made available which, in one region of the light guide path, avoids the known use of electric cables and light-guiding fibers and as a result avoids stressing the electric cables and light-guiding fibers under torsion and/or bending in the case of a relative movement of seat elements, as a result of which material fatigue fractures are advantageously prevented and the operational reliability of the transmission of light in the passenger seat can be increased. 
     In the previously described case in which the first and the second seat element are arranged fixedly relative to one another in the normal operating mode of the passenger seat, but are movable relative to one another in the maintenance mode of the passenger seat, it is possible, in a corresponding configuration, for a maintenance procedure to be advantageously simplified since disconnection of an electric cable or a light-guiding fiber can be avoided and/or necessary adjustment of a relative position between the first seat element and the second seat element can be carried out more easily. 
     The optical transmission unit can advantageously comprise a light emission unit, which is provided for emitting light, and a light-collecting unit which is provided for at least partially collecting the light emitted by the light emission in at least one operating state, as a result of which a simple arrangement for contactless transmission of light can be achieved. 
     In one advantageous configuration it is proposed that the light emission unit of the optical transmission unit is arranged at the first seat element, and the light-collecting unit of the optical transmission unit is arranged at the second seat element which is movable relative to the first seat element. As a result, a particularly simple solution for the transmission of light with simultaneous avoidance of mechanical stress of electrical cables and light-guiding fibers under torsion and/or bending in the case of relative movement of the seat elements can be achieved. 
     In addition it is proposed that the contactless transmission of the light from the first seat element to the second seat element which is different therefrom and is movable relative to the first seat element takes place in discrete regions, delineated from one another, of a relative position of the first seat element and of the second seat element. The “discrete regions, delineated from one another, of a relative position” is to be understood in this context as meaning, in particular, that a movement range of the second seat element relative to the first seat element is divided into a finite number of coherent regions, wherein regions with the transmission of light and regions without the transmission of light alternate with one another during a continuous movement of the second seat element from an initial position to an end position. As a result, in a corresponding configuration a display of a relative arrangement between the seat elements can be advantageously achieved. 
     In addition it is proposed that the light guide path be formed at least partially by at least one optical waveguide. An “optical waveguide” is to be understood in this context as meaning, in particular, a cylindrical body made of a translucent material whose optical index of refraction is greater than the optical index of refraction of a material which directly surrounds the cylindrical body. A “cylindrical body” is to be understood in this context as meaning, in particular, a body shape which arises as a result of displacement of a planar surface or curve along a straight line which does not lie in this plane. As a result, a particularly flexible way of guiding light can be achieved. Optical waveguides can preferably be manufactured from glass and/or transparent plastic. 
     In a known fashion, it is also possible to use bundles of optical waveguides which have an advantageously large optical aperture through which the light can be easily input into the optical waveguide and output therefrom. 
     Furthermore what is proposed is that the optical transmission unit have at least one collimator unit. A “collimator unit” is to be understood in this context as meaning, in particular, a unit made of optical elements, which unit is provided for generating a parallel light beam from an essentially punctiform light source. As a result, widening of the beam of light in a direction perpendicular to the light guide path can be achieved, as a result of which component tolerances and adjustment parameters are advantageously compensated and guiding of light is simplified. 
     Furthermore it is proposed that the light, output element be formed by a beam-widening element. A “beam-widening element” is to be understood in this context as meaning, in particular, an optical element with an optical axis, which element brings about divergence of the light beam in the case of an axis-parallel incident light beam in such a way that said light beam diverges from the optical axis. As a result, good visibility of light signals can be achieved, in particular in a lateral view of the light output element. 
     In a further advantageous configuration, the first seat element is formed by a seat housing element which is fixedly arranged relative to the floor of the means of transportation. In a corresponding configuration, reliable and cost-effective supply of a passenger seat or of a plurality of passenger seats with light from an external light source can therefore be achieved. 
     If in at least one operating state the contactless transmission of the light takes place between the seat housing element which is fixedly arranged relative to the floor of the means of transportation and a seat element which is movable relative thereto, given a corresponding configuration reliable and cost-effective inputting of light, for example for reading purposes or for displaying information, from a central light supply, permanently installed in the means of transportation, can also be made possible simultaneously in a plurality of passenger seats arranged one next to the other. 
     If the first seat element is formed by a seat bottom and the second seat element is formed by an armrest, a particularly reliable solution for transmitting light into the armrest can be made available. A “seat bottom” is to be understood in this context as meaning, in particular, a seat element of the passenger seat which supports the passenger in a seating position and which is usually equipped with fitted-on upholstery. In particular, light signals such as an “in-use light”, which a status of use of an additional device of the passenger seat, such as, for example, a voltage supply for a PC (Personal Computer) or for entertainment electronics (In Flight-Entertainment, IFE) can advantageously be transmitted from the first seat element, which is embodied, for example, as a seat bottom or as an element of a seat structure, into an armrest which is movable relative to the first seat element, where the light signals can be displayed in a way which can easily be displayed in a controlled manner by members of an on-board personnel team. Installation of an electric cable or of an optical waveguide formed by a light-guiding flexible fiber between the first seat element, and the movable armrest can be dispensed with, as a result of which the operational reliability of the signal display can be increased. 
     Further advantages are apparent from the following description of the drawings. Exemplary embodiments of the invention are illustrated in the drawings. The following description contains numerous features in combination. A person skilled in the art will also expediently consider the features individually and combine them to form further appropriate combinations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages are apparent from the following description of the drawings. Exemplary embodiments of the invention are illustrated in the drawings. The description and the claims contain numerous features in combination. A person skilled in the art will also expediently consider the features individually and combine them to form further appropriate combinations. 
         FIG. 1  is a schematic view of a passenger seat, embodied as a passenger seat in an aircraft, in an installed state, 
         FIG. 2  is a detail view of the passenger seat according to  FIG. 1  in a plan view, 
         FIG. 3  is a detailed view of the optical transmission unit having a collimator unit, 
         FIG. 4  is a schematic view of the dependence of light, emerging from a light output element, on a pivoting angle of an armrest of the passenger seat according to  FIG. 1 , 
         FIG. 5  is a schematic view of a further passenger seat, embodied as a passenger seat in an aircraft, in a normal position, 
         FIG. 6  is a schematic view of the passenger seat according to  FIG. 5  in a comfort position and lying position, and 
         FIG. 7  is a schematic view of the passenger seat according to  FIG. 5  in a front view. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows, in a schematic illustration in a side view, a passenger seat, embodied as a passenger seat  10  in an aircraft, in an installed state, in an interior space  12  of a means of transportation (not illustrated in more detail) embodied as an aircraft. However, in other embodiments the passenger seat can also be utilized in other means of transportation, specifically, for example, in a railway car, a coach or a passenger ship. 
     The passenger seat  10  in an aircraft has a plurality of seat elements  20 ,  22 ,  32 ,  34 . A first seat element  20  which is embodied as a seat bottom is arranged above a third seat element  32  which is embodied as a seat structure and with which the passenger seat  10  in an aircraft is stood on a floor  14  of the interior space  12  of the aircraft. A second seat element  22  of the passenger seat  10  in an aircraft is embodied as an armrest which is movable relative to the seat bottom. The armrest is movable between a position of use  24  and a release position  26  by pivoting about an armrest axis  30  in order to provide easier access to the passenger seat  10  in an aircraft for passengers with limited mobility. Both the position of use  24  and the release position  26  constitute end positions of a pivoting movement of the armrest about the armrest axis  30 . The passenger seat  10  in an aircraft has a sitting direction  18  which corresponds to a transportation direction or direction of flight in the example considered. The armrest axis  30  is arranged perpendicularly with respect to the sitting direction  18  and parallel to the floor  14  of the interior space  12  of the aircraft. 
     At a rear end, viewed in the sitting direction  18 , of the first seat element  20  which is embodied as a seat bottom, a further seat element  34 , formed by a backrest, is arranged, said further seat element  34  being pivotable between a sitting position  36 , arranged essentially perpendicularly with the floor  14  of the interior space  12  of the aircraft, and a comfort position  38  which is inclined with respect to the floor of the interior space  12  of the aircraft. 
       FIG. 2  shows a detail view of the passenger seat  10  in an aircraft in a plan view. The passenger seat  10  in an aircraft is arranged in an aisle  16  of the interior space of the aircraft.  FIG. 2  shows the armrest facing the aisle  16 , said armrest covering the seat bottom transversely with respect to the sitting direction  18  towards the aisle  16 . The passenger seat  10  in an aircraft comprises in a known fashion a voltage supply unit  40  (which is not illustrated in more detail) which is provided for supplying a laptop computer of a passenger with an operating voltage. In order to permit the passenger to monitor use of the voltage supply unit  40  by the laptop computer, the passenger seat  10  in an aircraft has a light output element  50  (“in-use light”) which is arranged as a beam-widening element in the form of a concave Fresnel lens made of transparent plastic on an aisle-side outer face  28  of the armrest. 
     In order to supply the light output element  50  with light, the passenger seat  10  in an aircraft has an optical transmission unit  42  which comprises a light emission unit  44  which is arranged at the first seat element  20  formed by the seat bottom, a light-collecting unit  46  which is arranged at the second seat element  22  formed by the armrest, and a light guide path  52  which runs from a first light input element  48  ( FIG. 3 ) of the optical transmission unit  42  to the light output element  50  of the optical transmission unit  42  and along which the light is guided. 
     The light emission unit  44  has a light source formed by a light emitting diode  54  and an actuation unit  56  (not illustrated in more detail) which is provided for supplying the light emitting diode  54  with an operating voltage as a function of the use of the voltage supply unit  40 . The light emitting diode  54  is arranged at the focal point F 1  of a first plano-convex optical collecting lens  58  which serves as a light input element  48  of the optical transmission unit  42  and is part of a collimator unit  62  of the optical transmission unit  42  ( FIG. 3 ). Light which is generated by the light emitting diode  54  is partially collected in a known fashion by the plano-convex first optical collecting lens  58  and converted into an approximately axis-parallel light beam  64 . 
     If the armrest is arranged in the position of use  24 , the approximately axis-parallel light beam  64  impacts, in the further course of the light, guide path  52 , on the light-collecting unit  46  which is arranged in the armrest. Firstly, the approximately axis-parallel light beam  64  is incident on a further plano-convex optical collecting lens  60  of the collimator unit  62  of the optical transmission unit  42 . As a result, the approximately axis-parallel light beam  64  is bundled at a focal point F 2  of the further plano-convex optical collecting unit  60  and is transmitted into an optical waveguide  66  of the light-collecting unit  46  which forms part of the further light guide path  52  subsequent to the further plano-convex optical collecting lens  60 . An end of the optical waveguide  66  which is remote from the light emitting diode  54  is connected to the light output element  50  of the optical transmission unit  42  at the aisle-side outer face  28  of the armrest, with the result that the light at the light output element  50  of the optical transmission unit  42  exits the passenger seat  10  in an aircraft ( FIG. 2 ). The optical waveguide  66  is embodied in a flexible fashion, as a result of which particularly good displaceability and a large degree of freedom of design in the selection of a location for the light output element  50  on the aisle-side outer face  28  of the armrest can be achieved. Basically, the optical waveguide  66  can, however, also be of rigid design by virtue of the fact that, for example, the light output element  50  and the further plano-convex optical collecting lens  60  are aligned in a direction which is oriented perpendicularly with respect to the sitting direction  18  and parallel to the floor  14  of the interior space  12  of the aircraft. 
     In an operating state which corresponds to an arrangement of the armrest in the position of use  24  and to simultaneous use of the voltage supply unit  40  by the passenger, the optical transmission unit  42  is provided for transmitting light in a contactless fashion at a location of the light guide path  52  between the first plano-convex optical collecting lens  58  of the collimator unit  62  and the second plano-convex optical collecting lens  60  of the light-collecting unit  46 . This location of the light guide path  52  differs from a location of the light input into the light input element  48  of the optical transmission unit  42  and also from a location of the light output from the light output element  50  of the optical transmission unit  42 . 
     If the armrest is pivoted out of the position of use  24  through an angle α max  as far as the release position  26 , part of a light intensity I arrives in a known fashion at the light output element  50  of the optical transmission unit  42  as a function of a pivoting angle α and geometric relationships within the collimator unit  62 . Starting from a limiting pivoting angle α s  of the armrest, no part of the approximately axis-parallel light beam  64  is instant on the light-collecting unit  46  any more, and light no longer exits the light output element  50  of the optical transmission unit  42  ( FIG. 4 ). 
     The contactless transmission of the light from the first seat element  20 , embodied as a seat bottom, to the second seat element  22 , which is different therefrom, and is embodied as an armrest and is movable relative to the seat bottom, occurs accordingly in two discrete regions  68 ,  70 , delineated from one another, of the pivoting angle α of the armrest, which pivoting angle α denotes a relative position of the seat bottom and of the armrest ( FIG. 4 ). In particular, the contactless transmission of the light takes place in a region of one of the two end positions of the armrest.  FIGS. 5 ,  6  and  7  show, as an alternative exemplary embodiment in a highly schematic illustration in a side view, a passenger seat which is embodied as a first class passenger seat  72  in an aircraft, in an installed state in an interior space  74  of a means of transportation (not illustrated in more detail) embodied as an aircraft. The passenger seat  72  in an aircraft comprises a plurality of seat elements  76 ,  78 ,  80  which are each embodied as a seat bottom, backrest and leg rest and are movable in a known fashion relative to one another between a normal position of the passenger seat  72  in an aircraft according to  FIG. 5  and a comfort position and lying position of the passenger seat  72  in an aircraft according to  FIG. 6  by means of a mechanical adjustment device which is known per se and which is not illustrated for reasons of clarity. The adjustment device also serves to stand the passenger seat  72  in an aircraft on a floor  84  of the interior space  74  of the aircraft. 
     The passenger seat  72  in an aircraft also has a seat housing element  82  which is fixedly arranged relative to the floor  84  of the interior space  74  of the aircraft and into which an armrest of the passenger seat  72  in an aircraft is integrated.  FIG. 5  illustrates the armrest facing an aisle  112  of the interior space  74 . During a movement of the passenger seat  72  in an aircraft between the normal position and the comfort position and lying position, the backrest is guided along an inner rear side  86  of the seat housing element  82  via the adjustment device with a headrest region  108 . 
     Safety guidelines require the passenger seat  72  in an aircraft to be set to the normal position during certain transportation situations (taxi, take-off, landing). Corresponding checking via the flight personnel is a customary component of relevant procedures. In order to simplify the checking, the passenger seat  72  in an aircraft has an optical transmission unit  88  whose function will be described below. 
     The optical transmission unit  88  comprises a light source  126  which is provided for simultaneously making available light from a plurality of optical transmission units in adjacent aircraft passenger seats of a row of aircraft passenger seats. For reasons of clarity, this arrangement which is familiar to a person skilled in the art is not illustrated in more detail. The light is coupled into a light guide path  90  of the optical transmission unit  88  at a light input element  92  embodied as a collecting lens ( FIG. 6 ). On a side of the collecting lens facing away from the light source  126 , a further part of the light guide path  90  is formed by an optical waveguide  96  which, in a partial region, is fixedly installed in the floor  84  of the interior space  74  of the aircraft and is routed as far as the passenger seat  72  in an aircraft. This part of the optical waveguide  96  is not illustrated in more detail. The optical waveguide  96  is also permanently installed along the inner rear side  86  of the seat housing element  82 , ends in an upper region  98  of the seat housing element  82 , and on this side is oriented parallel to a sitting direction  100  which corresponds to a transportation direction or a flying direction in the example considered. The optical waveguide  96  therefore forms a light emission unit of the optical transmission unit  88  which is arranged on the seat element which is embodied as a seat housing element  82 . In the headrest region  108  of the backrest, the passenger seat  72  in an aircraft has a light-collecting unit  102  which is formed by a further collecting lens ( FIG. 5 ). In the normal position, the passenger seat  72  in an aircraft, an optical axis  104  of the further collecting lens of the light-collecting unit  102  and an orientation direction of an end of the optical waveguide  96  arranged in the upper region  98  of the seat housing element  82  are largely aligned, with the result that light exits the optical waveguide  96  along the light guide path  90  in the upper region  98  of the seat housing element  82  and can enter the light-collecting unit  102 . 
     In this way, as a result of the optical transmission unit  88 , in an operating state of the normal position of the passenger seat  72  in an aircraft, contactless transmission of the light takes place between the seat housing element  82  which is fixedly arranged relative to the floor  84  of the interior space  74  of the aircraft and the seat element  78 , which is movable relative thereto and embodied as a backrest, of the passenger seat  72  in an aircraft. 
     The collecting lens of the light-collecting unit  102  is optically coupled to a flexible optical waveguide  106  which is laid within the backrest from a rear side of the headrest region  108  of the backrest as far as a side region  110 , facing the aisle  112 , of the backrest ( FIG. 7 ). An end of the optical waveguide  106  which is arranged there is oriented in a direction running perpendicular to the sitting direction  100  and parallel to the floor  84  of the interior space  74  of the aircraft, and is optically coupled to a further collecting lens  114  which is part of a collimator unit  118  whose method of function is identical to the method of functioning of the collimator unit  62  of the first exemplary embodiment, with the result that it is possible to dispense with an explanation in order to avoid repetitions at this point. The further collecting lens  114  converts the light at the end of the optical waveguide  106  into a virtually axis-parallel light beam 120 μm. A further collecting lens  116  is mounted as part of the collimator unit  118  at the inner rear side  86  of the seat housing element  82  in the direction in which that end of the optical waveguide  106  which faces the aisle  112  is oriented in the normal position of the passenger seat  72  in an aircraft. The collecting lens  116  collects part of the virtually axis-parallel light beam  120  and inputs this part into a rigidly embodied optical waveguide  122  which is guided by the collecting lens  116  as far as an outer side, facing the aisle  112 , of the seat housing element  82 . At one location of a light output, a light output element  94 , which is formed by a concave Fresnel lens made of plastic, is integrated into an outer surface  124  of the seat housing element  82 . In the normal position of the passenger seat  72  in an aircraft, light emerges from the Fresnel lens, with the result that rapid and reliable checking of the normal position of the passenger seat  72  in an aircraft is made possible by the flight personnel. 
     In this exemplary embodiment, accordingly at two locations of the light guide path  90  between the light input element  92  and the light output element  94 , which differ from the location of the light input into the light input element  92  and from the location of the light output from the light output element  94 , light is transmitted in a contactless fashion by the optical transmission unit  88  in a normal position of the passenger seat  72  in an aircraft, between the seat element  78  embodied as a backrest and the seat housing element  82  of the passenger seat  72  in an aircraft, these being movable relative to one another. 
     The contactless transmission of the light additionally takes place in two discrete regions, delineated from one another, of a relative position of the backrest and the seat housing element  82 , and corresponds to the profile according to  FIG. 4  if, instead of the pivoting angle α, a perpendicular movement path of the headrest region  108  of the backrest from the normal position is used as a parameter of a display.