JP2513503B2 - Delayed playback on both sides of the disc - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention reproduces a signal from a disc having information recorded on both the front surface and the back surface, such as an optical video disc record, by a single pickup. The present invention relates to a double-sided playback device.

(B) Conventional technology Conventionally, when playing back a disc recorded on both sides with a compact disc player or an optical video disc player, after the information on one side is reproduced, the disc is taken out and turned over. I needed to regenerate the other side. This is extremely troublesome in operation, and continuous reproduction on both sides is impossible. Therefore, as shown in JP-A-57-169936, continuous reproduction on both sides of the disc
Techniques have been proposed that are made possible by individual pickups.

In the prior art, a pickup is connected to a movable member through a crank rotation member so as to be rotatable by 180 degrees with respect to the disk surface, so that both surfaces of the optical disk can be continuously recorded or reproduced by one pickup. A possible optical disc device is disclosed.

However, in the above-mentioned conventional technique, it is necessary to separately provide a moving member for tracking with a rotating member for alternately inverting and positioning the optical axis of the pickup on both sides of the disc.
Further, there is a drawback that the positioning accuracy of the pickup on each surface is poor.

Therefore, in order to solve this problem, a guide member is directly extended in the radial direction on the upper and lower surfaces of the disc so that both sides of the disc can be reproduced, and the guide members are connected by a U-shaped guide. It is conceivable that one pickup can be configured so as to be able to move continuously on both sides of the disc in the radial direction. The movement of this pickup is schematically shown in FIGS. 2 and 3. In the figure, (1) is a disc for information reproduction, (2) is a spindle motor for rotating the disc, and (3) is a pickup. In addition, a mark "." Is provided on the right end of the pickup (3) for easy understanding.
Is attached. Fig. 2 shows the pickup at the lower P point of the disc (1) moved over the center of the disc to the left upper Q point, and Fig. 3 moved from the P point to the right R point. It is a figure. Incidentally, as an example of FIG.
There is a real public Sho 61-41163 (G11B21 / 02).

By the way, when the movement as shown in FIG. 2 is possible, when one surface of the disk is reproduced from the inner peripheral side to the outer peripheral side, that is, from the center of the upper surface of FIG. The movement of the pickup itself is the same when reproducing from the inner circumference side to the outer circumference side, that is, when reproducing from the center of the lower surface of FIG. 2 in the P point direction, that is, the side marked with "." Will be moved to. Therefore, the rotation direction of the feed motor that causes the movement of the pickup via the driving force transmission means can be maintained by maintaining the same direction during reproduction of any surface.

However, in the moving system as shown in FIG. 2, the moving amount of the pickup from one surface to the other surface becomes larger than that in the moving system as shown in FIG. However, it is inevitable that the size will increase.

(C) Problems to be Solved by the Invention As described above, it is more convenient to adopt the moving system shown in FIG. 3 in consideration of the moving time and downsizing of the mechanism. When adopted, the following problems occur.

That is, in the case of the moving system shown in FIG. 3, the pickup is moved from the center to the R point direction when reproducing the upper surface, and from the center to the P point direction when reproducing the lower surface, and the movement of the pickup itself is in the opposite direction, that is, during reproducing the upper surface. Is the mark "・" in front,
The mark “•” will be located at the rear during the lower surface reproduction.
Therefore, if the rotation direction of the feed motor is maintained in the same direction during double-sided reproduction as in the moving system shown in FIG.

(D) Means for Solving the Problems The present invention is a disk double-sided playback device configured to perform playback on both sides of a disk by moving a single pickup using the driving force of a feed motor. It is characterized in that the rotating directions of the spindle motor and the feed motor to be rotated are reversed at the time of reproducing from the inner circumference to the outer circumference of the disk surface and at the time of reproducing from the inner circumference to the outer circumference of the disk back surface.

(E) Operation Since the present invention is configured as described above, the time required for moving from one surface of the pickup to the other surface is minimized, and further, the mechanism is miniaturized as much as possible while reproducing both sides of the disc. realizable.

(F) Example An example of the present invention will be described below with reference to the drawings. FIG. 5 shows the appearance of an optical video disc player, in which the disc tray (3) for setting the disc (2) on the front panel (1) front surface is moved horizontally between the storage position and the pull-out position. It is possible.

FIG. 4 is a perspective view of a main part of the pickup feeding device,
The pickup (4) and the feed motor (5) are fixed on the base (6). A bracket (7) is adhered to the right end of the movable base (6), and a gear (8) is fixed to the motor shaft through the bracket (7). A pinion (pickup moving means) (9) meshing with the gear (8) is pivotally supported on the bracket (7). Two rollers (pickup moving means) (10) and (11) are pivotally supported on the left side surface of the movable base (6).

(12) is a rack that meshes with the pinion (9), and includes a lower linear portion (12a) that extends horizontally on the lower chassis,
An upper linear portion (12c) extending on the lower surface of the upper chassis in parallel with the lower linear portion (12a) and a U-shaped connecting portion (12b) connecting both linear portions are integrated. A guide groove (1) on which the pinion shaft (9a) can be loosely fitted is provided on the inner surface of the connecting portion (12b).
3) extends in a U shape.

(14) is a guide rail on which the rollers (10) and (11) slide, and similar to the rack (12), the lower linear portion (14a),
It is composed of an upper linear portion (14c) and a connecting portion (14b) connecting both linear portions. Like the rack (12), a guide groove (15) into which the roller shaft (10a) can be loosely fitted is provided on the inner surface of the connecting portion (14b), and roller guides are provided on the sliding surfaces of the rollers (10) and (11). A groove (116) is formed.

(16) and (17) are columnar guide poles fixed to the upper and lower chassis (20) and (21), and are arranged parallel to the linear portions of the rack (12) and the guide rail (14). There is.
The guide poles (16) (17) are screwed and fixed onto the chassis by screws (19) with a cylindrical fixing member (18) interposed between the guide poles (16) and (17).

A fitting hole (22) for fitting with the guide pole (16) is formed on the lower surface of the movable base (6).
2) The lower side is cut out for the escape of the fixing member (18). The disc (2) placed on the disc tray (3) has upper and lower linear portions (12a) (14a) and (12c).
It is clamped by the turntable (26) between (14c).

Reference numeral (30) denotes a push button switch arranged on the rack (12) at a boundary position between the lower linear portion (12a) and the connecting portion (12b), and the pinion (9) can be engaged with the upper surface thereof. It has a chewy shape. Therefore, every time the pinion (9) moves on the rack (12) and passes over the push button switch (30), the push button switch (30) is in a pressed state.

 Next, the operation of the apparatus of this embodiment will be described.

In the STOP mode, the standby position shown in FIG. 7 and FIG. 8A, that is, the connecting portion (12b) of the lower linear portions (12a) (14a)
(14b) The movable base (6) is located at the immediately preceding position.
However, the linear part (12a) below the push button switch (30)
On the side. Therefore, the pickup (4) never faces the disc (2).

In the PLAY mode, the feed motor (5) is driven, the driving force is transmitted to the pinion (9), and the position indicated by B while meshing with the rack (12), that is, the lower linear portion (12a) (14)
The movable base (6) moves to the tip position of a). At this position, the pickup (4) faces the innermost circumference of the surface A of the disc (2). After that, the spindle motor (25) rotates and the pickup (4) scans the disk (2). During this scanning, the tracking control circuit of the pickup operates, and this output is supplied to the Feed motor (5). As the surface A is scanned, the movable base (6) moves in the outer peripheral direction of the disk (2), that is, the lower linear portion. It moves on (12a) and (14a) toward the connecting parts (12b) and (14b). When all the scanning of surface A is completed, the movable base (6)
Via the connecting portions (12b) (14b), the upper linear portion (12c) (1
4c) reaches the tip and reaches the innermost position of the B side of the disk (2), at the same time the spindle motor (25) rotates in the reverse direction and the pickup (4) scans at the same time as the A side and moves. The base (6) moves toward the outer circumference of the disc (2). Movable base (6) through this connecting part (12b) (14b)
The push button switch (30) is once pressed by the pinion (9) in the process of shifting to the upper linear portions (12c) and (14c). The pickup (4) is scanning the disc (2), that is, the lower linear portion (12a) (1) of the movable base (6).
The movement state in 4a) is shown in FIG. The guide pole (16) is in the fitted state with the fitting hole (22) in order to prevent the pickup (4) from rattling in the vertical and horizontal directions and to improve the tracking accuracy of the pickup. . The same applies to the movement in the upper linear portions (12c) and (14c).

The movement state of the movable base (6) at the connecting portions (12b) and (14b) is shown in FIG. The pinion shaft (9a) and the roller shaft (10a) are loosely fitted in the guide grooves (13) (15) to maintain the meshing between the pinion (9) and the rack (12), and the rollers (10) (11) It moves into the roller guide groove (116) to guide the movement. When the scanning of the surface of the disc B is completed, the movable base (6) returns to the standby position and enters the standby state, the disc motor (25) is stopped, the disc clamp is released, the disc tray is raised, and the disc is removed. . The push button switch (30) is pressed once while the movable base (6) returns to the original standby position after the scanning of the surface of the disk B is completed.

FIG. 1 is a circuit block diagram of the device of this embodiment. The reproduced signal reproduced by the pickup (4) is the amplifier (3
The signal is amplified in 1) and supplied to the video / audio system circuit (32) that performs signal processing such as audio demodulation and video demodulation. Based on the synchronization signal (SY) obtained by the video / audio system circuit (32) and the reference signal (REF) from the syscon (33), the spindle motor circuit (34) performs rotation servo of the spindle motor (36). This output is supplied as a spindle motor control signal to a spindle motor drive circuit (37) through a motor control signal switching circuit, which will be described later, to drive a spindle motor (36) which is a DC motor and rotates a disk. . The spindle motor control signal is the + side terminal (34a) and-side terminal (34b) of the spindle servo circuit (34).
It is determined by the potential difference between the two.

The motor control signal switching circuit (35) is composed of movable contact pieces (35a) (35b) which are switched by an A / B signal described later.

For A / B signals, the pickup (4) is A on the disc (2)
It is determined whether the surface is being scanned or the surface B is being scanned, that is, whether the pinion (9) is moving the lower linear portion (12a) or the upper linear portion (12c) of the rack (12). It is a signal and is emitted from the syscon (33). This is set by pressing the push button switch (30) by the pinion (9).
Type flip-flop (38) output. That is, the FF (38) maintains the H level in the initial state while scanning the A surface, and the FF (38) is reset during the transition from the A surface to the B surface,
It becomes L level during B side scanning, the push button switch (30) is pressed again during transition from B side to the standby state, FF (38) is set, and it becomes H level during A side scanning and becomes B level during B side scanning. The determination is made as L level.

The motor control signal switching circuit (35) switches the movable contact pieces (35a) (35b) to the fixed terminals (35c) (35e) side by the A / B signal during A-side scanning, and the spindle servo circuit (34). + And-side terminals (34a) (34b) of the output is the + and-side terminals (37a) of the spindle motor drive circuit (37).
It is supplied to (37b), and the spindle motor (36) is driven to rotate normally, which is suitable for A-plane scanning. Further, during scanning of the B side, the movable contact pieces (35a) (35b) are switched to the fixed terminals (35d) (35f) side, and the + side terminal (34) of the spindle servo circuit (34).
a) is the negative terminal (37) of the spindle motor drive circuit (37).
In (b), the-side terminal (34b) is connected to the + side terminal (37b), the polarity of the motor control signal is inverted, and the spindle motor (36) is driven in reverse, which is suitable for B-side scanning.

The focus detection signal obtained from the AMP (31) is supplied to the focus servo circuit (39). The focus servo circuit (39) controls the beam to focus on the pit surface by causing the objective lens of the pickup (4) to follow the surface wobbling that occurs when the disk rotates. This focus servo circuit (39) The output is supplied to the focus motor drive circuit (40), and the objective lens that drives the focus motor (41) is driven in the vertical direction to absorb surface wobbling of the disk.

Similarly, the tracking detection signal obtained from the AMP (31) is input to the tracking servo circuit (41). The tracking servo circuit (41) causes the beam to follow the track swing generated in the radial direction due to the eccentricity when the disk rotates, and outputs the tracking control current so that the beam always traces one track. This tracking control current is supplied to a tracking drive circuit (tracking device) (43) via a jump pulse adding circuit (42) and flows to an electromagnetic mirror transducer (44) to control the tracking mirror.

The focus servo circuit (39) and the tracking servo circuit (41) stop the focus servo and the tracking servo when the pickup is moved using the jump pulse by the loop control signal (LC) from the syscon (33). Is controlled like.

The syscon (33) issues an A / B signal based on the output of the FF (38), and sends a jump pulse to the + side and-side terminals (33a) (33b) during slow and still, and a + side during picture search and review. And-side terminals (33c) (33d)
Sends a Feed pulse.

Jump pulse is + side terminal (33a) and-side terminal (33b)
The movable contact pieces (45a) (45b) are fixed to the fixed contact (45c) (45e) side when the pickup (4) scans the A surface by the jump pulse switching circuit (polarity inverting means) (45) that is given by the potential difference generated between them. , And the + side and-side terminals (33a) (33b) are connected to the + side and-side terminals (42a) (42b) of the jump pulse adding circuit (42), respectively, and B
Movable contact piece (45a) (45b) by A / B signal during surface scanning
Switches to the fixed contact (45d) (45f) side, and
The positive side terminal (33a) of 3) is connected to the negative side terminal (42b), and the negative side terminal (33b) is connected to the positive side terminal (42a), and the polarity of the jump pulse should be reversed compared to the A-plane scanning. become. The jump pulse thus supplied to the jump pulse adding circuit (42) is added to the tracking control current. As a result, the tracking mirror is swung in the inner circumferential direction by a predetermined number of tracks during the A-side scanning to perform a track jump.
Since the polarity of the jump pulse is reversed even during B-side scanning, the track is swung inward by a predetermined number of tracks, and an optimum track jump is performed.

Feed pulses for controlling the movement of the pickup (4) in the disc radial direction are issued to the + side and-side terminals (33c) (33d) of the syscon (33). This Feed pulse is given by the potential difference between the + side terminal (33c) and the-side terminal (33d). Feed pulse switching circuit (46) during A-plane scanning
The movable contact pieces (46a) (46b) of are switched to the fixed contacts (46c) (46e) side, and the + side and-side terminals (33) of the syscon (33) are
c) and (33d) are connected to the + side and-side terminals (47a) and (47b) of the feed pulse adding circuit (47), respectively, and the movable contact pieces (46a) and (46b) are connected to the fixed contact (46d) during B-side scanning. ) (46f) side, the polarity of the feed pulse is inverted with respect to that during A-plane scanning, and is supplied to the feed pulse adding circuit (47).

During normal playback, the feed servo circuit (48) controls the feed motor drive circuit (49) by the DC component of the tracking drive circuit (43), and controls the moving speed of the pickup.
The Feed motor (50) can be driven at a constant speed, but when the Feed pulse is added by the Feed pulse adding circuit (47), the Feed motor (5
0) to drive B even during A-plane scanning during picture search.
Even during surface scanning, the pickup can be moved in the outer peripheral direction at high speed. FIG. 11 shows a structure in which a protrusion (50) is formed on the side surface of the rack (12) corresponding to the lower linear portion (12a) in place of the push button switch (30) pressed by the pinion (9) to form a movable base. Pushbutton switch (5
In 1), a method for detecting the position of the pickup by closing the circuit during scanning the A surface and opening the circuit during scanning the B surface is shown. In the above-described embodiment, the normal reproduction path for scanning the B side after the A side scanning has been described. However, when ejecting in the A side reproduction state and designating the B side reproduction, or to the B side frame, When the set / reset of FF (38) is different from the normal one as when the access operation is designated, the A / B signal becomes L level regardless of the FF (38) output from the syscon (42).

(G) Effect of the Invention As described above, according to the present invention, by switching the rotation direction of the feed motor according to the reproducing surface, the time required for the pickup to move between surfaces is shortened, and a double-sided disk reproducing apparatus having a smaller mechanism is provided. It becomes possible to provide.

[Brief description of drawings]

FIGS. 1 and 3 to 11 relate to an embodiment of the present invention. FIG. 1 is a circuit block diagram, FIG. 3 is a diagram of a pickup feed path, and FIG. 4 is a perspective view of essential parts. 5 is an external view, FIG. 6 is an explanatory view of a guide pole, FIG. 7 is a top view, FIG. 8 is a side view, FIG. 9 is an explanatory view during horizontal movement, and FIG. 10 is an explanation during U-turn. FIG. 11 and FIG. 11 are explanatory diagrams of A / B surface detection, and FIG. 2 is a diagram showing a pickup feeding method for explaining a conventional example. (2) …… Disk ・ (4) …… Pickup, (5)
…… Feed motor, (36) …… Spindle motor, (6)
...... Movable base, (9) ...... Pinion (pickup moving means), (46) …… Feed pulse switching circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-77953 (JP, A) JP-A-59-175066 (JP, A) JP-A-56-22271 (JP, A) Actual development Sho-57- 188481 (JP, U)

Claims (1)

(57) [Claims] 1. A pickup for reproducing information from a disc having information recorded on both front and back surfaces thereof, a spindle motor capable of rotating the disc forward and backward, a feed motor capable of forward and reverse rotation, and a feed motor for the feed motor. The driving force moves the pickup in the radial direction of each surface of the disk to enable reproduction of each surface of the disk, and the pickup facing one surface of the disk faces the other surface of the disk. A pickup moving means for moving the spindle motor and the feed motor during a reproduction period from the inner circumference to the outer circumference of the surface,
And a motor control means for making a difference between the inner periphery of the back surface and the outer periphery during the reproduction period, and the front side in the traveling direction of the pickup during the reproduction period from the inner periphery of the front surface to the outer periphery is the inner surface of the back surface. A double-sided disc reproducing apparatus characterized in that it is on the rear side in the traveling direction during a reproducing period from the circumference to the outer circumference.