DE3941165A1 - CONTROL SYSTEM FOR THE RECORDER OF A DISK PLAYER - Google Patents

Abstract

In a disk player pickup control system, position data representing the present position of a pickup (2) is read from a disk. The distance from the present position to the home position of the pickup is calculated according to the position data thus read, and the pickup is moved to the home position according to the distance thus calculated. The above-described control system can move the pickup to the home position easily without employment of a mechanical switch. <IMAGE>

Description

The present invention relates to a turntable or a disk player and in particular a system for moving its transducer or the Scanning device in the rest position within the Record player.

In general, in the case of optical disks, such as digital audio disks and video disks, the starting point of the stored data is in the inner circumference or the inner periphery, in which area data of the content (table of contents, hereinafter referred to as "TOC" , if applicable) , such as the number of the program data which are stored and the addresses which represent the respective position of the program data are stored.

When playing such a disc or disc, the table-stored content TOC is first read with the pickup or scanning unit, then the pickup is moved into the start position of a specific or specified program data value and the pickup is moved along the tracks from the start position towards the outer circumference of the plate or disc moves. In order to be able to start the playback process quickly at any time, the scanning device or the pickup is moved to the position of the table of contents TOC of the record after each record play process, which, where applicable, is hereinafter referred to as the rest position or starting position.

With a conventional record player or one conventional disc player is the Sensor close by a mechanical switch the same moved to the rest position. In detail, the Sensor moved to the rest position when one Disc play is suspended or ended, such as follows: the transducer is turned inward with respect to the Disc moves and is then in place stopped at which the mechanical switch by the Transducer or the scanner is operated. This position is the starting or resting position.

As explained above, the conventional one The arrival of the pickup in the turntable Rest position detected by the mechanical switch that is close to the rest position. Therefore that points conventional control system for the scanner or the transducer the difficulty that the mechanical Switches must be arranged with high accuracy and productivity when mounting the turntable is significantly reduced. On the other hand, they can Rest position and the starting position for the saved Data on the disc are shifted against each other, if the plate is used for a long time or because of an eccentricity of the plate. It is therefore not advantageous to have such a stationary switch use the home or home position of the transducer or to determine the scanner.

It is therefore an object of the present invention to a record player or a control system for the Pickup or the playback device of a Turntable to specify where no mechanical Switch is used to put the transducer in the  Starting or rest position to move.

This object is achieved by a Control system for a turntable pickup solved according to the present invention in that a Position data value representing the momentary system of the transducer represented by a plate in which the Program data has been saved, is read the Distance between the momentary system and the rest position of the Sensor according to the reading Position data value is calculated and the transducer in the rest position according to the distance calculated in this way is moved.

For example, the pickup or scanner is moved to the home or home position to suspend playback from the disk or to eject the disk or to read the program table TOC to begin playback from the disk. For this purpose, a first address data value is read from the plate with the sensor or with the scanning device in order to detect the momentary system of the sensor and then the distance of the sensor between the momentary system thus detected and the starting or rest position is calculated and correspondingly of the distance calculated in this way, a carrier motor is controlled in order to move the pickup or the scanning device by this distance. The transducer is thus arranged in the initial or rest position.

Preferred refinements of the subject matter of the invention are set out in the subclaims.

The invention is based on a Embodiment and associated drawings closer  explained. In these show:

Fig. 1 is an explanatory diagram, partly as a block diagram, showing the arrangement of an embodiment of this invention

Fig. 2 is a flowchart for explaining the operations for raising a plate and for stopping the same, according to the embodiment of the present invention

Fig. 3 is a flowchart for explaining the process of starting playback from a disk according to this embodiment of the invention.

Fig. 1 shows a block diagram of the arrangement of a digital audio turntable or player according to an embodiment of the invention.

In the turntable, a disc D is rotated by a spindle motor 1 . In the case of a compact disc (CD), it is produced with a constant linear speed (CLV), a linear speed of 1.2 m / s to 1.4 m / s and with approximately 500 rpm on the inner circumference and approximately 200 rpm driven on the outer circumference.

The disk D has three surface sections or areas, an introduction area in which the stored data program of the content of the disk TOC is stored, a program area in which musical signals are stored and an execution area in which a program end signal is stored, these areas in in the order presented are arranged radially from the inside out on the plate, ie the lead-in area forms the innermost area, the lead-out area forms the outermost area and the program area is arranged between the lead-in area and the lead-out area. As explained above, the program data storage TOC contains those data values which indicate the number of program data (hereinafter referred to as "music data" or "pieces of music", as applicable), the addresses (ie the positions on the disk) of the start, spaces or Duration and end of each piece of music, the duration of each piece of music and the total time of the duration of all pieces of music. The TOC data are repeatedly saved on the disk up to the start position of the program area. The music data stored in the program is a plurality of pictures or units, each of which has a synchronizing signal, a subcode of control data and terminal extension data, data bits of music signals and error correction bits for correcting errors in the data bits. The subcodes also contain address data.

The data stored in the disk D is read with an optical pickup or pickup 2 and applied to a detection section 3 . The detection section 3 reads out a recording signal from the signal which is subjected to photoelectric conversion by the optical pickup 2 and applies it to a signal processing section 4 and supplies error signals such as a focus error signal and a tracking error signal to a servo section 5 .

In the signal processing section 4 , the recording signal is converted into a digital signal in order to detect the synchronization signal, demodulate the music signal and detect the subcode. The music signal is subjected to digital / analog conversion so that it is output as an analog audio signal, part of the synchronizing signal is applied to the servo section 5 , and the subcode is applied to a control section (CPU) 6 .

Depending on the error signal from the detection section 3 , the synchronizing signal from the signal processing section 4 and control signals from the control section 6 , the servo section 5 outputs servo signals for a focusing servo such that the focus or focusing coil of the optical pickup 2 is so is controlled so that the light beam is focused on the reflecting surface of the disc D , a track servo is controlled so that the track-determining coil of the optical pickup 2 is controlled so that the light beam hits a desired track and becomes a carrier -Servoeinrichtung controlled so that a carrier motor M is controlled so that it moves the body of the optical pickup 2 radially with respect to the plate D and a constant linear speed servo device is set so that the spindle motor M is driven at a constant linear speed.

The control section 6 consists of a microcomputer to output control signals for controlling the various sections of the turntable described above. The control section 6 also controls a feeder 7 to place or remove a disc or disc D on the disc player.

The turntable also has an operation / display section 8 . The operation / display section 8 has a group of controls such as a playback switch for playing music data stored on the disc D , a stop switch for pausing or stopping the playback of music data, and an eject switch for discharging a disc D. the turntable, a group of display units such as a display unit for displaying the operation of these control devices and a display unit for displaying the number of music data currently being played back and the playing time thereof. The operation of the turntable constructed in this way with respect to the movement of the optical pickup to the home or rest position will now be explained.

Fig. 2 is a flow chart for explaining the operation for returning the pickup 2 to the initial or rest position when the Auswerferschalter or the stop switch on the operation / display section 8 is operated.

In order to first detect the momentary system of the scanning device or the optical pickup 2 , the address data value, stored in the subcode, is read from the disk D (step S 1 ) and it is determined whether the pickup 2 is in the rest position or not (step S 2 ). If the pickup 2 is not in the initial or rest position, the distance between the momentary system and the rest position is calculated in order to thereby obtain the time required for the movement, ie the time T for which the carrier motor M is driven must be (step S 3 ). The pickup 2 is then moved for the time T (steps S 4 and S 5 ) and the carrier motor M is stopped (step S 6 ). The position of the sensor stopped in this way is then the starting or rest position.

It is then determined which switch in the work / display section 6 is operated, ie whether the ejector switch or the stop switch has been operated (step S 7 ). When the ejector switch is operated, the loader 7 performs a disc ejecting operation to eject the disc D from the disc player (step S 8 ). When the stop switch is operated, the turntable is stopped as it is.

Fig. 3 is a flowchart for explaining the operations for starting playback from a disc or disk.

When a disc D is brought into its playing position in the disc player by the loading device (step S 11 ), the circuit for the focusing servo is closed for a focusing operation (step S 12 ). The circuit for the track servo device for tracking is then closed (step S 13 ).

An image synchronization signal is then read out from the plate D in order to determine whether synchronization to the image or the data unit has been obtained within a certain period of time (steps S 14 and S 15 ). If the image synchronization is not established within a certain period of time, it is determined that the pickup 2 is located above the mirrored surface area, which is on the inside opposite to the insertion area of the plate D , and therefore the pickup 2 follows with respect to the plate D. moved outside. That is, the focus servo circuit and the tracking servo circuit are opened (step S 16 ) and the pickup 2 is moved outward for a certain period of time (steps S 17 and S 18 ), and then the step S 12 executed again.

If the image synchronization is detected as established in step S 14 , the address data value is read in from the plate D (step S 19 ) in order to detect the momentary system of the sensor 2 . That is, it is determined whether the pickup 2 is in its initial or rest position or not (step S 20 ).

As has been explained, the pickup 2 is normally moved to its rest position before the disc is ejected. However, in the case where, for example, the on / off switch for the energy supply has been switched off without the plate being ejected, the sensor cannot be moved back to the rest position or the starting position. It is therefore determined before playback from the disc D whether the pickup 2 is in its rest position or in the starting position or not. If it is determined that the pickup 2 is not in its rest position, then such a control is subsequently carried out which moves the pickup 2 into the starting or rest position.

First, the distance between the current position of the pickup 2 and the rest position is calculated, and thus the time required for the movement of the pickup 2, that is, the time required to drive the carrier motor M , is obtained (step S 21 ). Then the circuit for the focusing servo and the circuit for the tracking servo are opened (step S 22 ) and then the pickup 2 is moved inwards with respect to the plate D for the period T (steps S 23 and S 24 ). When the time T has elapsed, the carrier motor M is stopped (step S 25 ). The circuit for the focusing servo is closed again to focus the light beam and the circuit for the tracking servo is closed again to track the light beam on a track (step S 26 ).

In the state after the pickup 2 has moved to its initial or rest position, the address data value is read out from the disk D and the TOC position is calculated in accordance with this address data value thus read out (step S 27 ). The pickup is moved to the TOC position calculated in this way (step S 28 ), in which the contents of the TOC , ie the stored disk data, are read with the pickup 2 (step S 29 ) and the reproduction from the disk is performed. If it is determined in step S 20 that the transducer 2 is in the rest position, step S 27 is carried out to read the TOC . As previously explained, the TOC contains a variety of data required to start playback from the disc. It is therefore important and essential that the TOC be read before playback starts from the disc.

In the aforementioned embodiment, the Sensor moved to the home or rest position when the disc is ejected or stopped, or is played back. However, it should be noted that the invention is not limited to this. This means, it goes without saying that the technical concept the invention also e.g. applicable to the case where the light beam is defocused during playback and therefore the light beam has to be focused again, whereby the transducer has moved into the rest position got to.

In the control system for the transducer one Turntable according to the present invention Momentary creation of the transducer from the address data value detected and the distance between the momentary system and the Starting position is calculated and the transducer is for the route thus calculated moves so that it follows Going through the same is in the starting position. The means the transducer control system according to the present Invention is simple in its arrangement and can Transducers without using a mechanical switch move to the home or rest position.

The present invention relates to a control system for the pickup of a record player in which the Position data value representing the momentary system of the transducer represents, is read from the plate, the distance from the momentary system to the resting position of the transducer corresponding to the position data value thus read is calculated and the transducer in the initial or Rest position according to the distance calculated in this way is moved.

Claims (3)

1. Control system for a pickup of a turntable, characterized by an optical pickup ( 2 ) for an information storage disk which is driven in rotation by a spindle motor ( 1 ), the optical pickup ( 2 ) being connected to a servomotor ( M ), with a detection section for receiving a signal from the optical pickup ( 2 ), a signal processing section ( 4 ) which receives signals from the detection section ( 3 ) and which this to a central processor unit (CPU) and a servo section ( 5 ), which also signals from the central processor unit (CUP) and the detection section ( 3 ), an operating / display section ( 8 ), coupled to the central processor unit (CPU), a loading device ( 7 ) for the information storage disc ( D ) and a control connection device for signaling the Servo section ( 5 ) on the optical pickup ( 2 ), the servomotor ( M ) of the optical pickup hmers ( 2 ) and the spindle motor ( 1 ) of the information storage disc ( D ). 2. Method for controlling the pickup of a record player, characterized by the method steps:
Reading the position data value, which represents the momentary system of the transducer ( 2 ), from a disk ( D ) in which program data are stored,
Calculate the distance between the momentary system and the initial position of the sensor ( 2 ) according to the position data value read, and
Move the transducer ( 2 ) to the starting position according to the distance calculated in this way. 3. Control system according to claim 2, characterized by the step of obtaining a drive time for a carrier motor ( M ) for moving the transducer ( 2 ) into the starting position in accordance with the distance that was calculated in the distance calculation step.