Pioneer Electronic Corporation

Toshimasa Hangai

Koichi Ishitoya

Akihiko Tagawa

Kiyoshi Tateishi

Haruyasu Sakata

Hiromi Ota

A system for controlling a gain of an error signal amplifier, the system including an error signal generation device for generating a tracking error signal corresponding to an interval between a pickup information reading point, and a recording track, on a recording disk, a position detection unit for generating a position detection signal corresponding to a position of the pickup, an error signal amplifier for amplifying the tracking error signal, and a control device for controlling a tracking state of the pickup information reading point in accordance with an output of the error signal amplifier. The control device is operable for stopping a tracking state, moving the pickup information reading point in the radial direction of said disk, measuring a level of the tracking error signal at a plurality of different positions of the disk, calculating a plurality of gain data corresponding to the respective values of the levels of the tracking error signal measured at the plurality of positions, and writing the calculated gain data into a memory. The control device is further operable for re-starting the tracking state, detecting the position of the pickup information reading point, reading out, from the memory, the gain data corresponding to the detected position, and controlling the gain of the error signal amplifier according to the read-out gain data.

Gain control system for error signal amplifier in tracking servo

On a composite CAV/CLV disc, information signals and identification codes indicative of the time-base positions of the information signals are recorded in at least first and second, radially different regions in CAV and CLV formats. To play back the composite CAV/CLV disc, the present position of an information reading spot applied to the disc is detected as a present position code according to an identification code read from the disc, and a destination position to which the information reading spot is to be jumped is detected as a destination position code. Then, the number of tracks to be jumped which corresponds to the difference between the present position code and the destination position code is calculated according to different functions when both the present and destination positions are in one of the first and second regions only and in the other region only. The information reading spot is moved from the present position to the destination position over a distance depending on the calculated number of tracks.

CAV/CLV composite disk accessing method utilizing different accessing

An apparatus for monitoring a reading position for use in a disc player includes a positional information generating device for generating positional information of an information reading point in a direction of disc radius in accordance with the movement of the information reading point. The apparatus is configured to perform operations of detecting a condition that the information reading point is in one of at least lead-in and lead-out areas on the disc, storing each positional information by the positional information generating device at the time of the detection, comparing the positional information by the positional information generating device during the movement of the information reading point, and monitoring the position of the information reading point with respect to the lead-in and lead-out areas on the basis of a result of the comparison.

Apparatus for monitoring a reading position for use in a disc player

An apparatus for detecting a deviation of reading position for use in a disc player. A detection signal of the deviation of reading position is generated if a sync signal to be extracted from the read-out signal is not yielded for a predetermined time period under the presence of a lock detection signal which is produced when the focus servo system is in a locking condition. Owing to this structure, the deviation of the information reading light spot from a proper position is surely detected without enlarging the scale of circuits in the disc player.

Apparatus for detecting a deviation of a reading position for use in a

A slider-position detector for a disk player having a slider carrying a pickup and capable of moving in radial direction of a disk. The slider-position detector comprises an up-down counter which indicates a count variable according to the direction and moved distance of the slider, and controller which provides the count counted by the up-down counter as position data. The controller sets the up-down counter to a predetermined value when the counting rate of the up-down counter lowers below a predetermined rate while the slider moves in the predetermined direction. The slider-position detector is capable of surely detecting the position of the slider.

Slider-position detector for detecting the position of the slider of a

A slider control device in a disk player wherein normal speed information in each operation; mode of the slider, holding a pickup, is stored in a memory beforehand and the moving speed of the slider in each operation mode is detected and compared with the normal speed. The driving source of the slider is controlled according to the result of comparison. With this arrangement, even when the slider is driven at a high speed using, for example, a linear motor as a driving source for the slider, it is possible to execute secure speed control.

Slider control device for disk player

A high-speed search method for searching a target address and for use in a disc player system having a slider for positioning a pickup for reading an information signal recorded on a disc as tracks, in a disc radius, and a tracking servo system for causing an information detecting point of the pickup to follow the track. An accelerating-and-decelerating move control mode in which the slider is accelerated and subsequently decelerated with the tracking servo loop open, and a constant speed move control mode in which the slider is moved at a constant speed by using address data obtained from a signal from the pickup are prepared, and a distance from a present position of the pickup to the target address is detected. Operations of the accelerating-and-decelerating move control mode and subsequently the constant speed move control mode are executed and the tracking servo loop is closed when the distance is equal to or greater than a predetermined value, whereas the operation of the constant speed move control mode is executed without executing the operation of the accelerating-and-decelerating move control mode and the tracking servo loop is closed when the distance is smaller than the predetermined value.

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Tokorozawa, Japan

Toshimasa Hangai