Apparatus for controlling linear tracking arm in record player

A control apparatus for a linear tracking arm in a record player, comprising:

• an arm having signal pick-up means mounted at a portion thereof;
• an arm base for supporting said arm;
• driving means for driving linearly said arm base to drive thereby said signal pick-up means in a radial direction of a rotating record disc;
• tracking error angle detecting means for detecting a tracking error angle of said arm to produce thereby an electric signal representing proportionately said tracking error angle;
• a microprocessor receiving said electric signal representing proportionately said tracking error angle for arithmetically determining on the basis of the electric signal a servo output signal which is supplied to said driving means for causing said tracking error angle to be constantly zero;
• said electric signal comprising an electric voltage representing proportionately said tracking error angle, said voltage being an analogue voltage which is converted into a pulse signal having a pulse width proportional to said analogue voltage before inputting to said microprocessor, said microprocessor including a memory for storing therein said tracking error angle detected at a predetermined position of said arm, said arm being movable in the vertical direction;
• and
• a lift device which is detached from said arm when said arm is moved upwardly, said lift device being so arranged that said arm exhibits an offset angle of zero when said arm is moved upwardly, wherein said tracking error angle detected when said arm is moved upwardly is stored in the memory.