Abstract:
A switch mechanism actuates an electrically adjustable screen mount. The switch mechanism allows a user to select between a first automatic operation for stowing and deployment of the display screen ( 6 ), and a second, user adjustable operation for adjustment of the deployed position of the display screen ( 6 ), in order to tilt the screen back and forth. The adjustment back and forth may be accompanied by a movement upward or downward, with an upward movement when the top of the screen tilts away from the user, and downward movement when the top of the screen tilts towards the user. This can compensate for tilting of the surface to which the screen mount is attached, such as a seat-back.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention relates to a mount for a display screen. In particular the invention relates to a switch for operating a display screen mounted in a seat back and especially for use in automobile seat backs. 
       BACKGROUND TO THE INVENTION 
       [0002]    It is known to mount display screens, such as audio visual display screens and touch screen displays to the rear of vehicle seats. These display screens can be mounted directly to the backrest, or headrest, of a vehicle seat, in a fixed fashion or in which a user (viewer) may adjust the viewing angle of the display by pushing or pulling the display screen about a rotational axis. In some vehicles, such as aircraft and other passenger carrying vehicles, it is known to mount a display screen to an interior surface of the vehicle such as the interior roof surface, and the display screen may be in a fixed position, or mounted such that it may be electrically stowed and rotated from the stowed position into a viewable position as and when required. 
         [0003]    In certain vehicles, such as automobiles, it is preferred to mount the screen in a housing in the back of the seat, such that it is out of sight and protected by the housing. A particularly advantageous arrangement has the screen housed flat against the back of the seat, in a housing, from which it extends axially (upwards) out of the housing, into a viewing position. Especially, but not exclusively, in automobiles, where the position and orientation of the seat in which the screen is displayed is adjustable, it is useful to be able to adjust the viewing angle of the screen. US2009/0085383 discloses an example of such a mount, in which the display extends axially from a mount to a deployed position and is pivotally mounted from its top to the top of the support, so that the plane of the display is movable relative to the plane of the display support. 
         [0004]    However, this example, whilst effective, suffers certain drawbacks, in particular; the necessity to push the display screen back into position flush with the support before retracting it; and the potential for the display screen to change its position in relation to the pivot and to shake or rattle. Furthermore, although a motorised mechanism is suggested for adjusting the viewing angles, no details are given concerning how this motorisation might work. 
         [0005]    Embodiments of the present invention have been made in consideration of these problems, with a view to mitigating or alleviating them. 
       SUMMARY OF THE INVENTION 
       [0006]    According to a first aspect of the invention, there is provided an electrically adjustable display screen mount, comprising a control mechanism operable by a user to select between a first automatic operation for stowing and deployment of the display screen, and a second, user adjustable operation for user adjustment of the deployed position of the display screen; wherein the first automatic deployment operation effects movement between the stowed position and the last used deployment position. 
         [0007]    This can allow the initial deployment to be carried out at the press of a button, without holding on, whilst the fine adjustment of the angle can be carried out separately and movement to the last used deployment position is particularly convenient. 
         [0008]    The control mechanism may be a switch mechanism, the switch having a deployment memory position in which activation of the switch activates the first automatic operation to effect movement between the stowed position and a last used deployment position. 
         [0009]    The switch may have an adjustment mode position which activates the second user adjustable operation so that a user may adjust the deployment position of the display screen. 
         [0010]    The adjustment mode position may include two separate functions, one which enables a user to adjust the deployment position of the screen in one direction and another in the opposite direction. 
         [0011]    The deployment memory position may include two functions, one which is activated to deploy the display screen in a last used deployment position and the other which is activated to move the display screen to the stowed position. 
         [0012]    The switch may comprise a stowing position, a detent corresponding to the adjustment mode position, and a deployment memory position. 
         [0013]    The switch may be moved through the detent position into to the deployment memory position in order to deploy the display screen. 
         [0014]    The switch may be moved to the detent position in order for a user to adjust the required deployment position of the display screen by way of the second user adjustable operation. 
         [0015]    The detent may have two functions, a first function in which the detent position effects movement towards the display screen stowing position, and a second function in which the detent effects movement towards the deployment memory position. 
         [0016]    The switch may be moveable in at least two directions, and the stowing position and deployment memory position of the switch may be effected by opposite movement of the switch. 
         [0017]    The, user adjustable operation may enable rotation of the display screen up to 15°. 
         [0018]    The switch may further comprise a neutral position, to which the switch is urged in absence of any user input. 
         [0019]    The first automatic operation may cause the screen to move faster than the second user adjustable operation (to allow for fine adjustment). 
         [0020]    A seat may be provided, comprising an electrically adjustable display screen mount as set out above, wherein user adjustment of the deployed position of the screen changes the viewing angle such that the base of a display screen mounted on the display screen mount moves longitudinally away from the back of the seat and/or the top of a display screen mounted on the display screen support moves longitudinally towards a headrest. 
         [0021]    Movement of the base longitudinally away from the back of the seat, and/or movement of the top longitudinally towards a headrest may occur simultaneously with axial movement in the deployment direction. This means that in adjusting the angle, upward movement of the screen is accompanied by tilting of the screen such that the base moves towards the user and/or the top moves away from the user—this is particularly useful because when a seat is tilted backwards, its top will be lower and its angle will be towards the user of the screen. Accordingly, extension of the display screen mount results in angling the screen away from the user and lifting it higher, thereby compensating both for the angle and the height of the screen. 
         [0022]    Movement of the adjustable display screen mount in the retraction direction may be associated with a corresponding movement of the base of the screen towards the back of the seat, and/or movement of the top of the screen away from the headrest. 
         [0023]    The present invention also provides a seat comprising a display screen mount as set out above, mounted in the seat back, for viewing by a passenger in the seat behind. A vehicle comprising such a seat is also provided. The vehicle may be an automobile. 
     
    
     
       DETAILED DESCRIPTION OF THE INVENTION 
         [0024]    In order that the invention may be more clearly understood, embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which: 
           [0025]      FIG. 1  shows a cross sectional view of a seat including a display screen mounted on a display screen mount according to the invention, in a stowed position; 
           [0026]      FIG. 2  shows a cross sectional view of the seat of  FIG. 1  with the display screen mount in a deployed position, set at a forward tilt; 
           [0027]      FIG. 3  shows a cross sectional view of the seat of  FIGS. 1 and 2  with the display screen mount in a deployed position, set at a neutral tilt; 
           [0028]      FIG. 4  shows a cross sectional view of the seat of  FIGS. 1 to 3  with the display screen mount in a deployed position, set at a backward tilt; 
           [0029]      FIG. 5  shows a cross sectional view of the seat of  FIGS. 1 to 4  with the display screen mount in the deployed position showing backward, forward and neutral tilts; 
           [0030]      FIG. 6  shows a rear view of the display screen of attached to the screen mount of  FIGS. 1-5 ; 
           [0031]      FIG. 7A  illustrates a side view of a switch mechanism for the display screen mount of  FIGS. 1-6 , in a neutral position; 
           [0032]      FIG. 7B  illustrates the switch mechanism in a deployment memory position; 
           [0033]      FIG. 7C  illustrates the switch mechanism in a reclining adjustment position; and  FIG. 7D  illustrates the switch in an inclining adjustment position. 
       
    
    
       [0034]    With reference to  FIGS. 1 to 5 , a seat  1  of an automobile (not shown) has a main body portion  2 , a headrest  3  and a housing  4  at the rear. The housing  4  has a slot  5  in its upper surface, through which a display screen  6  can move between a stowed position (shown in  FIG. 1 ), within the housing  4 , to a deployed position outside the housing  4  (shown in  FIGS. 2-5 ). 
         [0035]    As shown in  FIG. 6 , the display screen  6  is attached to a display screen support  7  e.g. by fastenings  8 , e.g. nuts/bolts. The display screen support  7  is pivotally mounted to a first slide  201 , via a hinge  9  and fixedly attached to a second slide  202 . 
         [0036]    Referring once again to  FIGS. 1-5 , the first slide  201  is slidably mounted at its lower end to a first track  203  e.g. by wheels (not shown), although with suitable materials/lubrication wheels may not be necessary. The first track  203  is linear and extends generally along the axis of the body of the seat  1 , parallel to the main plane of the housing  4  which defines the seat back. 
         [0037]    The first slide  201  is drivably mounted, for example by a rack and pinion mechanism, or a spindle drive. Indeed, in an alternative embodiment, the first slide  201  could include a rack mechanism, or the spindle and the separate track  203  could be eliminated. Accordingly, when the first slide  201  is driven, it follows the linear path defined by the first track  203 . The first slide  201  could even, for example, be the rod of an (e.g. hydraulic) actuator (such as a ram), with the cylinder defining the first track  203 . 
         [0038]    The second slide  202  is also slidably mounted (e.g. by wheels) at its lower end, this time to a second track  204 . The second track  204  is non-linear and is shaped to guide the display screen support  7  as it moves between the deployed and stowed positions. In its lower region, the non-linear second track  204  has a linear portion  205 . The linear portion  205  runs parallel to the linear path defined by the first track  203 . 
         [0039]    In an upper region, best seen in  FIGS. 2-4 , the second track  204  has a non-linear portion  206 , which deviates from the linear path defined by the linear portion  205  in the lower region; the non-linear portion  206  curves away from axis of the linear path, longitudinally, towards the housing  4  and away from the axis of the body  2  of the seat  1 . The non-linear portion  206  then straightens up to continue to define a straight path  207 , which will be followed by the slide  102 , upwards and away from the body  2  of the seat  1 . Although it is straight, the path  207  is considered to be non-linear as it does not continue the linear path defined by the linear portion  205  of the second track  204  in its lower region. 
         [0040]    In use, to deploy the display screen  6  from the stowed position shown in  FIG. 1 , an electric switch  60  (shown in  FIGS. 7A to 7D ) is actuated. This causes the first slide  201  to be driven along the linear path defined by the first track  203 . The non-driven second slide  202  is thus caused to follow a linear path along the linear portion  205  of the non-linear second track  204 . This linear path is followed as the display screen  6  emerges from the slot  5  in the housing  4 . 
         [0041]    Then, when the display screen  6  has almost entirely emerged from the slot,  5  the lower end of the second slide  202 , which is slidably connected to the second track  204  reaches the non-linear portion  206 . The first slide  201  continues to follow a linear motion, driving the display  6  upwards. However, the lower end of the second slide  202  follows a non-linear path, curving away from the axis of the body  2  of the seat  1 . Because the display support  7  is pivotally mounted to the first slide  201  and fixedly mounted to the second slide  202 , this movement causes the support  7  to it pivots about the hinge  9 , with the result that the base of the display support  7  (and the display  6 ) moves longitudinally away from the axis of the body  2  of the seat  1 . Correspondingly, the top of the display tilts towards the axis of the body  2 , and towards the headrest. 
         [0042]      FIG. 2  shows the configuration of the display screen  6  and its mount when this tilting action has just begun, with the lower end having travelled round the curved region of the non-linear portion  206  onto the start of the straight path  207 . In this position, where the second slide has not travelled far along the straight path  207  making up part of the non-linear portion  206 , the display screen is almost parallel with the axis of the linear first track  203 . Since the axis of the body  2  of the seat  1  is leaning backwards, the top of the screen is tilted backwards with respect to the seat  1 , or at a forward tilt, with respect to the user. 
         [0043]    As the first slide  201  is driven along the linear path defined by the first track  203 , the lower end of the second slide  202  continues up the straight path  207  in the non-linear portion  206  of the second track  204 , it eventually reaches the end of the path  207  at its uppermost and longitudinally furthest from the body  2  of the seat  1  (closest to the housing  4 ) as shown in  FIG. 4 . At this point, the second slide  202  is at its greatest angle with respect to the first slide  201  and therefore, the display  6  is angled backward, with its top closest to the headrest and its base further from the axis of the body  2  of the seat  1 , towards the user. 
         [0044]    In between the forward tilt shown in  FIG. 2  and the backward tilt shown in  FIG. 4 , when the first slide  201  is not fully extended, the second slide is positioned between the curved portion of the non-linear region  206  and the end of the straight path  207 . Accordingly, a neutral position can be defined, e.g. halfway along the straight path, in which the angle of the display is roughly in line with the axis of the headrest, and most likely to be at a suitable viewing angle to an average sized rear-seat passenger, if the seat  1  is occupied by an average sized occupant in an ordinary position (e.g. height and orientation of the seat body. 
         [0045]    Backrests of seats are normally rotatably mounted at their base. Accordingly, leaning back the seat body  2  lowers the height of the slot  5  through which the display screen  6  exits the housing  4 . On the other hand, leaning forward towards a straight upright position raises the height of the slot. 
         [0046]    The display screen  6  exits the slot in a plane parallel to the axis of the seat body  2 . Therefore, it too is leant backward with respect to the seat i.e. tilted forward with respect to the viewer. Accordingly, when the seat  1  is leant back, the user (viewer) is likely to wish to tilt the display screen  6  backwards (that is to say, to lean the top of the screen in the direction of the back of the screen, away from the viewer). This is achieved by extending the first slide  201  as far as possible, which also raises the height, therefore both bringing about the correct angle and adjusting towards a better height. 
         [0047]    In use, a user wishing to deploy the screen  6  from the stowed position as shown in  FIG. 1 , to a deployed position as shown in  FIGS. 2 to 5  may manipulate a switch  60  as shown in  FIGS. 7A-7D  in order to activate the electric drive. At this point, the first slide  201  is driven upwards along the linear path defined by the first track  203 , which causes the second slide  202  to be driven along the second track  204 . As the slides  102 ,  202  are moved along the tracks  203 ,  205 , the display screen  6  is moved upwards and follows the path described above, as the second slide  202  reaches the non-linear portion of the second track  204 . 
         [0048]    In a new installation of a seat  1  and display screen  6  in a vehicle, for example, the support  7  and hence display screen  6  may be provided with a default deployment memory position, this may be the neutral position as shown in  FIG. 3 , in which it is expected that the seat  1  is upright and the height of the passenger behind the seat is such that the screen is at eye level. The position of the display screen  6  may not be optimal, especially if the body  2  of the seat  1  is moved to a different position, e.g an especially upright, or unusually laid back position, in which case, for an average height viewer, the orientation of the display screen  6  would need to be reclined towards the “forward tilt” and inclined towards the “backward tilt” positions shown in  FIGS. 2 and 4  respectively. 
         [0049]    As shown in  FIGS. 7A-7D , the seat  1 , or another part of the vehicle (not shown), e.g. an armrest (not shown) is provided with a switch  60  which enables adjustment of the deployment position of the display  6  by a user. The switch  60  is a rocker switch having five positions  66   a ,  66   b ,  66   c ,  66   d ,  66   e , corresponding to the stowing position  66   a , a inclining detent  66   b , a neutral position  66   c , a reclining detent  66   d  and a deployment memory position  66   e . The switch  60  is manipulated by a user, who can move the switch between all of the positions. In use the switch  60  is urged to the neutral position  66   c  shown in  FIG. 7A , unless a user manipulates the switch  60 . A user may move the switch  60  in one direction, through the reclining detent  66   d  to the deployment memory position  66   e  as shown in  FIG. 7B . A user may also move the switch  60  through the inclining detent  66   b  to the stowing position  66   a  in the opposite direction. A user may also move the switch  60  to the reclining detent  66   d , as shown in  FIG. 7C , in order to adjust the deployment position of the display  6  in one direction, and to the inclining detent  60   b , to move the display position in the opposite direction as shown in  FIG. 7D . The deployment memory position  66   e , when activated, effects the default position of the deployment of display  6  as shown in  FIG. 3 , and the stowing position  66   a  when activated, effects the stowed position of display  6  as shown in  FIG. 1 , the display being entirely situated beneath the slot  5  in the housing  4  of the seat  1 . 
         [0050]    The inclining and reclining detents  66   b ,  66   d  between the stowing position and deployment memory position have respective functions, the reclining detent  66   d  enables the user to adjust the position of the display  6  in a forward (and downward) direction towards user in the position shown in  FIG. 2 , and the inclining detent  66   b  enables a user to adjust the position of the display in a backward (and upward) direction towards the position shown in  FIG. 4  away from the user. In use, a user may activate either detent  66   b ,  66   d  of the switch  60 , which activates the electric drive to drive the first slide  201  in the required direction, in order to adjust the position of the display screen  6  relative to the seat  9  and the user. When the required position has been achieved, a user may release the switch  60  which moves back to the neutral position  66   c , so that the display screen  6  remains in the desired position. At this point, suitable electronic means may store the data of the new display screen deployment position, and seat position as the new default deployment memory position. A user may then stow the display screen  6  when required, by moving the switch  60  to the stowing position  66   a . When the user next utilises the display screen  6 , moving the switch  60  to the deployment memory position  66   e  will automatically move the display screen  6  to the last known deployment memory position and user may adjust the display screen  6  again as necessary. 
         [0051]    When the switch is moved to the deployment memory position  66   e , or the stowing position  66   a , the display screen  6  is caused to move at a first, relatively fast, speed, on the other hand, when the switch is moved to the inclining detent  66   b , or the reclining detent  66   d , the display screen  6  is caused to move at a second, relatively slow, speed, in order to achieve fine adjustment. 
         [0052]    The above embodiment is/embodiments are described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.