Turntable for a disc-shaped information carrier and player provided with such a turntable

Abstract

The invention relates to a turntable ( 1 ) for a disc-shaped information carrier ( 2 ), such as a DVD, having a central round opening ( 21 ). The turntable comprises a centering element ( 3, 4 ), which is rotatable about an axis of rotation ( 7 ) by means of a driving element. The centering element ( 3, 4 ) comprises a fixed centering member ( 3 ) having a supporting surface ( 8 ) for the information carrier, and a further centering member ( 4 ) for final centering of the information carrier, said further centering member being movable in axial direction along the axis of rotation between an upper position, in which the centering member is unloaded, and a lower position, in which the centering member is loaded. An end-centering portion ( 32 ) of the movable centering member has the shape of a first truncated cone, which is directed upwards and which has a first apex angle. The turntable is further provided with a pressure member ( 5 ) for pressing the information carrier onto the support surface, as a result of which the movable centering member is moved from the upper position to the lower position. The turntable is used in a player for reading and/or writing disc-shaped information carriers having a central round opening, such as a CD or DVD player.

1 . A turntable for a disc-shaped information carrier having a central round opening, comprising a centering element which is rotatable about an axis of rotation by means of a driving element, characterized in that the centering element comprises a fixed centering member having a supporting surface for the information carrier, and a movable centering member for final centering of the information carrier which is axially movable along said axis of rotation between an upper, unloaded position and a lower, loaded position, with an end centering portion of said movable centering member being in the form of an upwardly extending, first truncated cone having a first apex angle, and in that the turntable is furthermore provided with a pressure member for pressing the information carrier onto the supporting surface, as a result of which the movable centering member moves from the unloaded position into the loaded position.  
     
     
         2 . A turntable as claimed in  claim 1 , characterized in that the turntable is provided with a supporting element by means of which the movable centering member is supported substantially without play in radial direction with respect to the fixed centering member.  
     
     
         3 . A turntable as claimed in  claim 2 , characterized in that the supporting element, seen in axial direction, is arranged in a position which substantially corresponds to a position which the information carrier occupies on the supporting surface in use, seen in axial direction.  
     
     
         4 . A turntable as claimed in  claim 2 , characterized in that the supporting element is provided with a circular cylindrical guiding surface which is present on one of the two centering members and which is concentrically positioned relative to the axis of rotation, and with a number of guide members arranged in a circle which are present on the other centering member and which abut against the aforesaid guiding surface substantially without play, seen in radial direction.  
     
     
         5 . A turntable as claimed in  claim 1 , characterized in that a pre-centering portion of the fixed centering member has the shape of an upwardly extending second truncated cone having a second apex angle which is greater than the first apex angle.  
     
     
         6 . A turntable as claimed in  claim 1 , characterized in that the turntable is provided with spring means acting between the fixed centering member and the movable centering member.  
     
     
         7 . A turntable as claimed in  claim 6 , characterized in that said spring means are formed by a membrane spring.  
     
     
         8 . A turntable as claimed in  claim 7 , characterized in that the membrane spring is fixedly connected only either to the fixed centering member or to the movable centering member.  
     
     
         9 . A turntable as claimed in  claim 1 , characterized in that the movable centering member is provided with a lead portion adjacent to the upper side of the end centering portion, which lead portion is in the shape of an upwardly extending third truncated cone having a third apex angle which is greater than the second apex angle.  
     
     
         10 . A turntable as claimed in  claim 1 , characterized in that magnetic means are accommodated within the fixed centering member for attracting the pressure member.  
     
     
         11 . A turntable as claimed in  claim 1 , characterized in that the first apex angle ranges between 25 degrees and 45 degrees.  
     
     
         12 . A turntable as claimed in  claim 11 , characterized in that the first apex angle ranges between 30 degrees and 40 degrees.  
     
     
         13 . A player for reading and writing a disc-shaped information carrier having a central round opening, which player comprises a turntable for the information carrier, characterized in that said turntable is a turntable as claimed in any one of the preceding claims.