Abstract:
Instrument cluster and pointing device for a car or other vehicle, the pointing device being mounted rotatable about a rotation axis and having a shaft element in the vicinity of the rotation axis, the pointing device further comprising at least one of a light guide element or a mirror element in the region of the shaft element and comprising one of an image forming element or an aperture, wherein the one of the image forming element or the aperture and the one of the light guide element or the mirror element are able to be rotated about the rotational axis with the shaft element, and wherein light incident to the shaft element is directed from the one of the light guide element or the mirror element to the image forming element or aperture and projecting to a visible surface.

Description:
BACKGROUND 
       [0001]    The present disclosure relates generally to the field of display apparatus, and particularly to instrument clusters for cars and other vehicles. More specifically, this disclosure relates to the lighting of pointers inside of an instrument cluster of a vehicle. 
         [0002]    Instrument clusters for vehicles often include an instrument panel that includes a pointer. The pointer is typically configured to point to some value of a vehicle parameter or other parameter such as fuel level, vehicle speed, preferred or preset vehicle speed, engine speed, engine temperature, time, etc. In many cases, the pointer can be rotated about a rotational axis and is in many cases connected to a stepper motor by means of a rotating shaft. The pointer generally comprises an axial portion extending substantially parallel to the rotational axis about which the pointer can be rotated. The pointer generally further comprises a radial portion extending substantially in a direction perpendicular to the axial portion and perpendicular to the rotational axis. 
         [0003]    It has become popular to light the pointer using light sources such as LEDs (light emitting diodes). In general, LEDs might be arranged around the outside of the shaft. As the pointer moves around the rotational axis, the pointer would be lit by subsequent LEDs around the shaft. Light from the LEDs would enter the pointer and make the pointer appear as if it were glowing. According to other solutions, one or a plurality of LEDs are located behind the center of the shaft such as to directly inject light into the shaft. 
         [0004]    With these current instrument cluster configurations, the pointer usually comprises a light guide element such that the light emitted by the LED or plurality of LEDs is guided by the light guide and directly emitted towards a user such that there is only one appearance of the pointer. 
         [0005]    There remains a continuing need to provide a more cost effective manufacture and assembly process of instrument cluster elements and to provide for an enhanced visibility of the pointer and the position of the pointer such that an enhanced clarity of the displayed information can be achieved. 
       SUMMARY 
       [0006]    The present invention overcomes the disadvantages of the prior art by providing a design for a pointer or a pointer device for an instrument cluster of a car or other vehicle, wherein the pointing device is mounted rotatable about a rotation axis, wherein the pointing device has a shaft element in the vicinity of the rotation axis, wherein the pointing device further comprises at least one of a light guide element or a mirror element in the region of the shaft element, wherein the pointing device further comprises one of an image forming element or an aperture, wherein the one of the image forming element or the aperture and the one of the light guide element or the mirror element are able to be rotated about the rotational axis with the shaft element, and wherein light incident to the shaft element is directed from the one of the light guide element or the mirror element to the image forming element or aperture. 
         [0007]    With the pointing device according to the present invention, it is possible to provide a further pointing effect of the pointing device by the use of a projected image formed by the image forming element or the aperture, the image being reflected by a region of the appliqué of the instrument cluster towards the user of the pointing device. 
         [0008]    The pointing device according to the present invention comprises one of a light guide element or a mirror element in the region of the shaft of the pointer device. The light guide element preferably emits (or the mirror element reflects) light towards one of an image forming element or an aperture. The light emitted by the light guide element or reflected by the mirror element is projected (through the image forming element or aperture) to a part of the display surface visible to the driver of the vehicle or to the user of the instrument cluster. The display surface is preferably a formed appliqué surface of the instrument cluster according to the present invention. 
         [0009]    It is particularly preferred according to the present invention that light incident to the shaft element is visible to a user of the instrument cluster only after having passed one of the image forming element or the aperture and reflecting on the appliqué. It is particularly preferred that the projection of light to a part of the display surface is operational or visible to the driver of the vehicle or to the user of the instrument cluster only in certain lighting conditions, especially during night lighting conditions, i.e. reduced ambient lighting from the exterior of the vehicle, especially in the form of sunlight. Such reduced ambient lighting conditions are usually relevant during night time but also within tunnels or underbridges. 
         [0010]    Very preferably, the pointing device comprises one of a covering element or a shroud. This serves to prevent light incident to the shaft element from being reflected or otherwise ejected from the intended optical path within the pointing device so that light incident to the shaft element is prevented from being reflected in the direction to the driver or the user of the pointing device. 
         [0011]    According to a preferred embodiment of the present invention, the pointing device further comprises a focusing element, wherein the focusing element is able to be rotated about the rotational axis together with the shaft element, and wherein incident light is directed from the one of the image forming element or the aperture to the focusing element. 
         [0012]    By means of the focusing element, especially a focusing lens, the light emitted by the light guide element or reflected by the mirror element is projected (through the image forming element or aperture) to a part of the display surface visible to the driver of the vehicle or to the user of the instrument cluster. The display surface is preferably a formed appliqué surface of the instrument cluster according to the present invention. 
         [0013]    According to all embodiments of the present invention, it is preferred that the one of the light guide element or the mirror element is integrally formed with (or integrated in) the shaft element and/or that the one of the image forming element or the aperture is integrally formed with (or integrated in) the one of the light guide element or the mirror element and/or that the one of the image forming element or the aperture and the one of the light guide element or the mirror element are integrally formed with (or integrated in) the shaft element and/or that the focusing element is integrally formed with (or integrated in) the one of the image forming element or the aperture and/or that the focusing element and the one of the image forming element or the aperture are integrally formed with (or integrated in) the one of the light guide element or the mirror element. 
         [0014]    Such integrally forming (or integrating) of different elements of the pointing devices allows for a more simple construction of the pointing device and a less cost intensive construction and assembly of the pointing device. 
         [0015]    Another object of the present invention relates to an instrument cluster of a car or other vehicle, wherein the instrument cluster comprises a pointing device, wherein the pointing device is mounted rotatable about a rotational axis, wherein the pointing device has a shaft element in the vicinity of the rotation axis, wherein the pointing device further comprises at least one of a light guide element or a mirror element in the region of the shaft element, wherein the pointing device further comprises one of an image forming element or an aperture, wherein the one of the image forming element or the aperture and the one of the light guide element or the mirror element is able to be rotated about the rotational axis together with the shaft element, and wherein light incident to the shaft element is directed from the one of the light guide element or the mirror element to the image forming element or aperture. 
         [0016]    With the instrument cluster according to the present invention, it is possible to provide a further pointing effect of the pointing device by the use of a projected image formed by the image forming element or the aperture, the image being reflected by a region of the appliqué of the instrument cluster towards the user of the pointing device. 
         [0017]    It is preferred according to the present invention that the light incident to the shaft element is visible to a user of the instrument cluster only after having passed one of the image forming element or aperture and reflecting on the appliqué. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a perspective view of the interior of a vehicle having an instrument cluster schematically shown. 
           [0019]      FIG. 2  is a top view on a display surface of an instrument cluster of a vehicle according to an exemplary embodiment. 
           [0020]      FIG. 3  is a sectional view of the instrument cluster of a vehicle according to the exemplary embodiment. 
           [0021]      FIG. 4  is an exploded view of the pointer of the instrument cluster according to the exemplary embodiment. 
           [0022]      FIG. 5  shows two top views according to different lighting conditions on a display surface of the instrument cluster of a vehicle according to the exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Referring generally to the figures and in particular to  FIG. 1 , a vehicle interior is partly shown according to an exemplary embodiment. The vehicle interior includes an instrument cluster  100  for providing information regarding vehicle parameters such as fuel level, vehicle speed, engine speed, engine temperature, etc. Preferably, the vehicle interior usually also comprises a steering wheel (not shown) or another steering device ergonomically located so as to allow for a fatigue-proof usage by a driver or another user of the vehicle. 
         [0024]    Referring to  FIG. 2 , a pointer system or pointer device  10  for an instrument cluster  100  (or cluster) is shown together with a display surface  20  of the instrument cluster  100 .  FIG. 2  shows a top view of the instrument cluster  100 . The pointer system  10  or pointing device  10  according to the present invention provides a projected light image  11 . The projected light image  11  of the pointer system is shown in  FIG. 2  on a left hand part of the instrument cluster  100  or cluster display surface  20 . The display surface  20  is the surface which can be normally seen by the driver or user of the instrument cluster  100 . In  FIG. 2 , a display graduation is schematically shown on the left hand side of the display surface  20  in the vicinity of the projected light image  11 . By means of the projected light image  11  being in the vicinity of the graduation (or other symbolic indication on the display surface), it is possible for the driver to see the value of the vehicle parameter by means of the location of the projected light image  11 . The projected light image  11  can have any form or shape, e.g. round, rectangular, triangular, elongated or the like. In the example shown in  FIG. 2 , the projected light image  11  has a triangular shape (or an arrow like shape) such as to point to a certain part of the graduation in order to display the value of the vehicle parameter. 
         [0025]    In  FIG. 3 , a sectional view of the instrument cluster  100  according to the exemplary embodiment is shown. The direction of view of  FIG. 3  is parallel to the plane of the main extension of the display surface  20 , i.e. substantially orthogonal to the direction of a rotational axis  12  of the pointing device  10 . The pointing device  10  comprises a shaft element  13 . The shaft element  13  extends substantially along the axis of rotation  12  of the pointer  10  or pointing device  10 . 
         [0026]    Furthermore, the pointing device  10  comprises one of a light guiding element  14  or a mirror element. The light guiding element  14  can be provided such that a surface  14 ′ serves as a mirror (where total reflection occurs). Alternatively, a mirror element (not shown), e.g. a metallized surface at the location of the surface  14 ′, can be used in the context of the present invention. The one of the light guiding element  14  or the mirror element serves to direct light emitted by an LED  110  (emitting light which is incident to the shaft element  13  of the pointing device  10 ) towards one of an image forming element  15  or an aperture. The image forming element  15  is preferably provided as an image aperture. The image forming element  15  or image aperture moves together with the pointing device  10 , i.e. follows the rotational movement of the pointing device, i.e. of the shaft element  13 . Preferably, the pointing device  10  also comprises a focusing element  16 . The focusing element  16  also moves together with the pointing device  10 , i.e. follows the rotational movement of the pointing device, i.e. of the shaft element  13 . From the focusing element  16 , the light is projected towards the display surface  20 . According to all embodiments of the present invention, the focusing element  16  is preferably provided as a focusing lens. 
         [0027]    Preferably, the functions of the shaft element  13  and of the light guiding element  14  are integrated in the same element, i.e. the shaft is provided by a light guiding material and is preferably shaped such as to be able to guide the incident light (received from the LED  110  or from a plurality of LEDs (axially) behind the shaft element  13  of the pointing device  10 ) in a direction towards the image forming element  15 . 
         [0028]    According to an alternative embodiment of the present invention, the one of the image forming element  15  or the aperture can also be integrated in the shaft element  13  of the pointing device  10  and/or in the one of the light guiding element  14  or mirror element. 
         [0029]    According to a further alternative embodiment of the present invention, the focusing element  16  can also be integrated in the shaft element  13  of the pointing device  10  and/or in the one of the light guiding element  14  or mirror element. 
         [0030]    According to still a further alternative embodiment of the present invention, the focusing element  16  can also be integrated together with the one of the image forming element  15  or the image aperture. This integration can be provided such that the integrated focusing element and image forming element are provided (radially) spaced from the shaft element  13  or integrated in the shaft element  13  or near the shaft element  13  of the pointing device  10 . 
         [0031]      FIG. 4  shows an exploded view of an exemplary embodiment of the pointing device  10  of the instrument cluster  100  according to the present invention. In this embodiment, the pointing device  10  comprises, besides the shaft element  13  or pointer stem, a carrier  18  and a top shroud  19 . The carrier  18  and the top shroud  19  extend substantially along the radial direction of the pointing device  10 . Between the carrier  18  and the top shroud  19 , the image forming element  15  or image aperture as well as the focusing element  16  or focusing lens are located. Both the carrier  18  and top shroud  19  (or cover element) serve to mechanically secure the focusing element  16  and the image forming element  15  with respect to the pointer shaft or shaft element  13  during the rotational movement of the pointing device  10  about the rotational axis  12 , i.e. between different rotational positions of the pointing device  10  according to the present invention. 
         [0032]    Preferably, the top shroud  19  is not backlit. This means that the top shroud  19  is only visible during daylight lighting conditions inside the vehicle and that the driver or user of the pointing device  10  does not or at least not precisely see the position of the pointer during nighttime lighting conditions, except by means of the projected image  11  visible on the display surface  20 . 
         [0033]      FIG. 5  shows two top views according to different lighting conditions on a display surface  20  of the instrument cluster  100  according to the exemplary embodiment of the present invention. The appearance of the instrument cluster  100  with the pointing device  10  according to the present invention which corresponds to daytime lighting conditions, i.e. illuminated lighting conditions, is shown on the left hand side of  FIG. 5 . The appearance of the instrument cluster  100  with the pointing device  10  according to the present invention which corresponds to nighttime lighting conditions, i.e. non-illuminated lighting conditions, is shown on the right hand side of  FIG. 5 . From the nighttime appearance of the instrument cluster (right hand side of  FIG. 5 ), it can be seen that the pointing device  10  is not visible or at least not very well visible or at least not actively backlit with regard to the pointer stem or pointer shaft (shaft element  13 ) as well as with regard to the radial part of the pointing device  10  (i.e. the part of the pointer which extends along a substantially radial direction with respect to the rotational axis  12 ). However, from the nighttime appearance, it is visible that the image  11  (or projected image  11 ) of the image forming element  15  is projected on the display surface  20  such that the position of the pointing device  10  can easily be detected by a driver of the vehicle or a user of the instrument cluster  100 . During nighttime appearance of the pointing device  10 , there is preferably a backlit graphics visible on the display surface  20 . In order to realize such a backlit graphics, preferably further light sources, like further LEDs, are provided in the instrument cluster  100 , especially behind at least a part of the display surface  20 . From the daytime appearance, it can be seen from  FIG. 5  (cf. left hand side of  FIG. 5 ) that the pointer stem or pointer shaft (shaft element  13 ) as well as the radial part of the pointing device  10  (i.e. the part of the pointing device  10  which extends along a substantially radial direction with respect to the rotational axis  12 ) is very well detectable such that the position of the pointing device  10  can easily be seen by the driver of the vehicle or the user of the instrument cluster. 
         [0034]    According to an alternative embodiment of the present invention, the projected image can always be lit, i.e. in both modes of operation of the instrument cluster, which means that the LED  110  emitting light towards the shaft element  13  is illuminated both during daytime mode of operation and during nighttime mode of operation. 
         [0035]    According to another alternative embodiment of the present invention, the projected image  11  can be lit only in the mode of operation of the instrument cluster relating to the nighttime appearance or during nighttime mode. In this alternative embodiment, it is possible to save energy that would otherwise be needed to illuminate the LED.