Pickup arm drive device
AssigneePioneer Electronic Corporation
InventorJunichi Yoshio
Life of this patent
Estimating the term…
Abstract
In a pickup arm drive device of a record player capable of automatically selecting a desired music on a record disc on which a plurality of pieces of music are recorded, at least two inter-music sensors are arranged near a stylus on the pick-up arm to detect inter-music spaces on the record disc. The outputs of the sensors are subjected to processing and by using the resultant processed outputs, the driving of the pickup arm is switched from "lead-in" or "return" operation to an inter-music position servo operation. Therefore, the stylus of the pickup arm can be lowered exactly onto the inter-music space on the record disc even if the record has an eccentricity or warp.
Claims14
A pickup arm drive device in a record player provided with an automatic music selection device, said record player further including a pickup arm, a cartridge carried on said pickup arm and having a stylus, said pickup arm being movable with respect to a record disk in at least a swinging direction and said record player including means for lowering said pickup arm at a desired position, said drive device comprising:
- at least one light source disposed in the vicinity of said stylus;
- a first light receiving element disposed on said pickup cartridge for detecting light emitted from said light source and reflected by said record disk and providing an output;
- a second light receiving element disposed on said pickup cartridge and offset with respect to said first light receiving element along said swinging direction, said second light receiving element receiving light emitted from said light source and reflected by said record disk, and providing an output;
- subtraction means for subtracting the output of said first light receiving element from said output of said second light receiving element to provide a subtraction output;
- and
- servo means for effectuating servo control of said pickup arm during lowering of said pickup arm, said servo means comprising reference means (VR) for generating a reference signal having a predetermined reference value, means for comparing said reference signal and subtraction output to generate a servo control signal, and means responsive to said servo control signal for driving said pickup arm.
A pickup arm drive device for a record player of the type having an automatic music selection device, a pickup arm, a cartridge on said pickup arm and carrying a stylus, said pickup arm being movable with respect to a record disk in at least a swinging direction, said pickup arm drive device comprising:
- at least one light source disposed in the vicinity of said stylus;
- a first light receiving element disposed on said pickup cartridge for receiving light emitted from said light source and reflected by said record disk, and providing an output;
- a second light receiving element disposed on said pickup cartridge and offset with respect to said first light receiving element in said swinging direction, said second light receiving element receiving light emitted from said light source and reflected by said record disk, and providing an output;
- subtraction means for subtracting the outputs of said first and second light receiving elements to provide a subtraction signal;
- and
- means for halting the swinging movement of said pickup cartridge and for lowering said pickup cartridge when the absolute value of said subtraction signal falls below a predetermined value.
A pickup arm drive device for a record player of the type having an automatic music selection device, a pickup arm, a pickup cartridge disposed on said pickup arm and carrying a stylus, said pickup arm being movable with respect to said disk in at least a swinging direction and said record player including means for lowering said pickup arm at a desired position, a pickup arm drive device comprising:
- at least one light source disposed in the vicinity of said stylus;
- a first light receiving element disposed on said cartridge for receiving light emitted from said light source and reflected by said record disk, and providing an output;
- a second light receiving element disposed on said cartridge and offset with respect to said first light receiving element in said swinging direction, said second light receiving element receiving light emitted from said light source and reflected by said record disk, and providing an output;
- subtraction means for substracting the outputs of said first and second light receiving elements in order to provide a subtraction signal, said subtraction signal having a first value when said pickup arm approaches said desired position;
- and
- means for halting the swinging movement of said pickup cartridge and for lowering said pickup cartridge when the outputs of said first and second light receiving elements become equal to each other after said subtraction signal has taken said first value indicating that said pickup arm has approached said desired position.
In a record player for playing a record disk, said player being of the type having a pickup arm carrying a pickup cartridge with a stylus thereon, said pickup arm being movable with respect to said disk in at least a swinging direction and said record player including means for lowering said pickup arm at a desired position, and an automatic music selection device, a pickup arm drive device comprising:
- first detection means in the vicinity of said stylus for detecting light reflected from said disk and providing an output;
- second detection means in the vicinity of said stylus and offset with respect to said first detection means along said swinging direction, and providing an output;
- and
- control means for providing a first signal in response to a detected difference exceeding a maximum value between said detection means outputs and for lowering said pickup arm when the difference between said detection means outputs becomes less than a predetermined value after the occurrence of said first signal.
Dependencies are inferred from the claim text.