Pioneer Electronic Corporation

Hiroshi Yokota

Ryuichi Naito

Hiroyuki Hirano

Shinichi Naohara

Katsumi Ishii

Kanya Matsumoto

Yoshifumi Tsukada

Yoshifumi Tsukuda

A disc player has a first array of pickup devices arranged in a line for reading information from a disc and a second array of pickup devices arranged in a parallel line. The pickup devices are each independently movable along their respective lines with the devices of the first line offset from the devices of the second line so as to form a zigzag pattern.

Disc player with objective lens arranged in a zigzag pattern

A disc player includes: a plurality of pickup devices for reading information from a disc and a plurality of guide devices arranged radiately from a center of the disc, each for radially transferring one of the pickup devices. The guide devices are arranged so that each alternate pickup device is raised or lowered toward the inner circumferential portion of the disc.

Disc player with alternating ascending/descending guide devices

A disc player includes at least one pickup device, which includes a pair of objective lenses for reading information from a disc. The pair of objective lenses are independently movable in the radial direction of the disc by a magnetic field generated by a common magnet.

Disc player with parallel objective lenses

A disc player includes: a plurality of pickup devices for reading information from a disc; and a plurality of guide devices having a longitudinal axis for transferring the pickup device, the longitudinal axis being directed in a direction rotated by a predetermined angle with respect to a radial direction of the disc.

Disc player

A PLL circuit, to which an input signal is inputted, is provided with: a voltage controlled oscillator for outputting an output signal; a control voltage generation circuit for generating a control voltage to lock phases of the input and output signals by a loop, and outputting the generated control voltage to a control input terminal of the voltage controlled oscillator; and a central frequency setting circuit for setting a central frequency, to which a frequency of the output signal is to be pulled-in, to the control voltage generation circuit. A pulling-in circuit for the PLL circuit is provided with: a sweep range setting circuit for setting a sweep range, where the frequency of the output signal is to be pulled-in to the set central frequency, on the basis of the set central frequency; a lock detector for detecting whether or not a pulling-in operation is completed in the PLL circuit, and outputting a lock signal when the pulling-in operation is detected to be completed; and a sweep range control circuit for controlling the control signal generation circuit to generate the control signal to repeatedly sweep the frequency of the output signal through the set sweep range during the pulling-in operation until the lock signal is supplied thereto.

Pulling-in circuit for PLL circuit, pulling-in method for PLL circuit,

A record medium of disc type is recorded by a constant linear velocity. The record medium is reproduced by a reproducing apparatus, which reads the information from the rotated record medium into a buffer memory by a transmission rate corresponding to the number of rotation of the record medium and outputs the read information from the buffer memory to an external apparatus by a predetermined output rate. The method of reproducing the record medium by the reproducing apparatus is provided with the steps of: setting radial ranges of a plurality of virtual zones on the record medium, each of which is in a ring shape, and the number of rotation for each of the virtual zones, on the basis of upper and lower limit values of the transmission rate, which are predetermined to be higher than the predetermined output rate, a radius of the most inner circumference of an area where the information is recorded on the record medium, and a memory capacity of the buffer memory; rotating the record medium by a constant angular velocity in each of the set virtual zones by the set number of rotation; and reading the information from the rotated record medium by the transmission rate corresponding to the set number of rotation in each of the set virtual zones.

Method and apparatus for reproducing information recorded on CLV disc

A rotary head type magnetic recording and reproducing device intended for dubbing one tape from another wherein the effects of vibration, jitter, etc., during the dubbing operation are substantially eliminated. First and second rotary heads, one for each of the two magnetic tapes, are carried by respective rotary disks. The rotary disks are mounted on a single shaft, and the latter is rotated by a single drum motor.

Growing community of inventors

Tokorozawa, Japan

Hiroshi Yokota