Pioneer Electronic Corporation

Toshio Hirano

Junichi Yoshio

Masayuki Yoshida

Kenichiro Yasukawa

Isami Kenmotsu

Atsuo Ikeda

Takashi Kikuchi

Kunio Abe

Shinya Takahashi

Masao Ono

A disk detecting apparatus in which disks of different diameter are mounted and centered on a movable carrier having an extended radial aperture. As the carrier is inserted into the case of the disk player, a single detector detects the presence and size of any of the disks through the aperture.

Disk detecting apparatus

A disk player for both optical and compact disk having two spindle motors for the two types of disk. One of the spindle motors is located far enough from the other spindle motors to receive its own smaller disk and is movable to allow the other spindle motor to receive the larger disk. The disks are carried on a tray to the respective spindle motor and are clamped thereagainst. The tray comprises two carriers for two disk sizes which are separable from each other inside the disk player.

Dual-sized disk player

A front-loading type disk player, such as a video or compact disk player, having an improved front loading mechanism which absorbs any play or backlash that occurs during the movement of the carriage so that the carriage is accurately controlled in position as it moves in and out of the housing of the player. Support members for the chassis have a stopper with which the carriage comes into contact when the disk reaches a predetermined playing or recording position. An energizing force is applied during the time an accelerating mechanism drives the carriage in the direction of the accommodation position inside the housing, continuing for a short time after the carriage contacts the stopper. The excess force is absorbed by urging the carriage against the stopper.

Loading mechanism for disk player

A method for performing sound field enlargement in a digital audio reproducing apparatus such as a compact disc player. A sum is calculated between each received pair of right-channel and left-channel data read from the disc, and the resulting sum data is stored in a random access memory. After a predetermined delay time, the sum data are read from the memory and multiplexed with the then-incoming right-channel and left-channel data. The resulting data stream is converted to respective right-channel, left-channel, and delayed-sum analog signals, which are then subjected to low-pass filtering. The filtered signals are processed in a conventional manner to yield outputs signals which, when reproduced, produce a perception of an enlarged sound field.

Sound field enlarging device and method

A digital audio system constructed to reproduce an audio signal by separating low frequency components of a PAM (Pulse Amplitude Modulation) signal made up of pulses being produced at predetermined time intervals and representing a predetermined audio signal, the digital audio system including a pulse width control means for varying the pulse width of each of the pulses of the PAM signal in accordance with a predetermined command signal, whereby an automatic fade in and fade out operation is performed.

Digital audio system with automatic fade in and fade out operations

A dual drive system for an automatic record player of a type in which programmed music selection can be carried out. The drive system includes a mechanical first drive system for mechanically driving the pickup arm and an electromagnetic second drive system for driving the pickup arm using an electromagnetic force. Circuitry is provided for selecting between the two drive systems in accordance with the selected operational mode of the player or the position of the pickup arm.

Growing community of inventors

Saitama, Japan

Toshio Hirano