JPH0249278A - Disk player - Google Patents

Abstract

PURPOSE:To perform roll control at the time of generating abnormality where no synchronizing signal is obtained and to prevent the abnormal rotation of a spindle motor by detecting the position of a pickup in the diameter direction of a disk from the quantity of rotation of a gear mechanism. CONSTITUTION:When the pickup and another supporting base 3 are driven and a switch (SW) 98 is turned on, a base 3 is sent from an inner periphery to an outer periphery, and a lower plane is reproduced, and the spindle motor 21 is rotated in a forward direction. The output of the output 15a and 15b of a photosensor are taken out via the gear mechanism, and phase difference is detected at a phase comparison circuit 120, and an up command is issued to a counter 121, and a count value is inputted to a conversion circuit 122, then, the position can be found. After the reproduction of the outermost periphery is completed, the base 3 is driven by the gear mechanism, and it arrives at an upper straight line traveling end via a circular arc shape guide part, then, a SW 97 is turned on. Traveling direction is reversed, and the base 3 is moved from the inner periphery to the outer periphery on a disk plane, and the motor 21 is rotated in a reverse direction, then, an upper plane is reproduced. By employing such constitution, the number of components can be reduced, and also, the abnormal rotation of the spindle motor can be blocked while performing the roll control with high accuracy.

Description

Detailed Description of the Invention (a) Field of Industrial Application The present invention relates to a disc player that reads information from a disc on which information is written on both sides. It relates to a device for transporting.

BACKGROUND ART Conventionally, there are two types of optical video discs: one in which video signals are recorded at a constant angular velocity, and one in which video signals are recorded at a constant linear velocity to increase recording density. Constant angular velocity (
CAW) disc, if the rotating speed of the day frame is 1800 rpmKM, the information can be read easily.
However, when playing a disk with constant linear velocity (CLV), if the radial position of the pickup that reads the signal is changed too much, the signal will not be read accurately. It is possible. In other words, when playing around the inner circumference, 18
The disk must be rotated at 600 rpm near the outer circumference at 00 rpm. Normally, this control of the rotational speed of the disk, so-called spindle servo, is made possible by extracting a horizontal synchronizing signal from the reproduced signal and changing the rotation of the disk so that the wave number remains constant during this period.

However, if the horizontal synchronization signal cannot be retrieved due to a temporary dropout caused by a scratch on the disc, the spindle servo will be disturbed, and for example, when the pickup is playing from the inner circumference toward the outer circumference, the above-mentioned problem may occur. When servo disturbance occurs and the rotation of the disk deviates from the signal reading fX range, the spindle motor goes out of control and signal reproduction becomes impossible.

Therefore, the rotational speed of the disk is uniquely determined by the radial position information of the pickup relative to the disk, which is independent of the reproduction signal from the pickup. A method can be considered to prevent the abnormal rotation 8 of the motor from occurring.

The problem here is how to detect the position information of the pickup in the disk radial direction.

As an example of a method for detecting this position information, JP-A-58-1
Publication No. 22673 (G11B21102) K has a light emitting element disposed on a movable base that supports a pickup and moves in the radial direction of the disk, and emits light onto the chassis along the movement path of the movable base! A pickup position detection means for optically detecting the pickup position by fixing a conversion element is disclosed.

(c) AM to be solved by the invention In the above-mentioned position detection means, the photoelectric conversion element fixed to the chassis needs to extend over a wide range from the inner circumference to the outer circumference of the disk, which hinders space saving. . Mano, Japanese Unexamined Patent Publication No. 62-287476 (G11B
21102), a movable base that supports a pickup is moved along a U-shaped guide means, and when the above-mentioned position detection means is adopted in a disc player that plays all sides of a disc with a single pickup, the movable base and is a separate light 1! Two conversion elements are required, one for the front surface and the other for the back surface of the disk, which inevitably increases the number of parts. Furthermore, when the rotational speed of the spindle motor is always determined uniquely based on position information, the precision of delicate rotational control is inferior to that of spindle motor servo using a synchronizing signal sound.

The present invention provides a movable base that supports a pickup and moves across both sides of the disk, includes a drive motor, a plurality of gear mechanisms driven by this motor, and detects the amount of rotation of this gear mechanism. It is characterized by being equipped with a rotation amount detection means, and detecting the radial position of the pickup with respect to the disk from the rotation amount detected by the rotation amount detection means. The disc rotation is controlled so that the frequency of the signal becomes a predetermined value, and when a synchronization signal is not obtained, the disc rotation is controlled based on the position information of the pickup in the disc radial direction.

(E) Function Since the present invention is configured as described above, the position detection means can be integrated on the movable base side, so there is no need to arrange position detection members on each of both surfaces. Moreover, abnormal rotation of the spindle motor is prevented while maintaining highly accurate rotation control.

(f) Example An embodiment of the present invention will be described below with reference to the drawings.

As shown in Fig. 2, a disk drive device (2) consisting of a spindle motor head and a turntable head is attached to the lower chassis 0, and a support base (movable base) is mounted opposite the drive device (2). ) (3) and dormitory structure (5)
will be placed.

A pickup 32) consisting of an optical system including a semiconductor laser and an objective lens is fixed approximately at the center of the support base (3), and left and right gear mechanisms (11) 02) are mounted on both sides.
(In Figure 2, if all of these gear mechanisms were shown, the perspective view would be extremely complicated, so only a part of them is shown.) In addition, there is a 7-ohd motor (drive motor) that drives all of these gear mechanisms. )(a) is included. still,
These gear mechanisms (10u) and the feed motor (A) constitute a self-propelled mechanism (4) for the support base (3).

The dormitory mechanism (5) includes left and right guide rails (61) (@) each formed in a U-shape. Both guide rails (
51) (The disks are fixed on the lower chassis so as to be parallel to each other and respectively parallel to the disk radius line (D) as shown in FIGS. 1 and 3.

Each guide rail (51 bars) is set on a turntable as shown in Figure 4, and extends horizontally below the disc on which information is optically recorded on both sides. Inside the dormitory. (A), the inside of the dormitory that moves horizontally above the disk scream (B), and the inside of both dormitories (A) (B)
) and an arc-shaped dormitory interior (C). Therefore, the support base (3) is a downward straight line $ inside the dormitory (A)?
When the pickup moves in the radial direction of the disc by moving in the direction of 1lIIIff from the turntable 4, the pickup reproduces the back side, that is, the bottom side of the disc. After playing this back side, the arc-shaped dormitory interior C
By passing through C), the disc is reversed and moved to the upper surface side of the disc, and the disc surface can be reproduced while moving upward straight into the dormitory.

(61) (6) As shown in FIG.
The lower and upper guide balls are supported by η, and are in a positional relationship parallel to the lower and upper linear movement inside the dormitory (A) and (B) of the guide rail. On the other hand, the support base (3) is provided with a slide groove having an arcuate cross section through which the guide balls (61, 6) can pass. When the pickup ■ reproduces a signal, the slide groove (7) is connected to the guide ball (6).
1) The button slides on the circumferential surface of (6), and this button prevents wobbling during linear movement and improves tracking accuracy.

The self-propelled mechanism (4) of the support base (3) is shown in Figures 1 and 6.
As shown in the figure, support base (3J left guide rail (δ
The left gear mechanism (l I) located on the η side and driven by the feed motor (g), and the right guide rail (+121
It is composed of a left gear mechanism (12) arranged on the side and a right gear mechanism (12) connected via a connecting shaft i4η. The left gear mechanism (equipped with the first to fifth gear wheels (42 decoys 1441) and the left drive gear mechanism, which are pivotally supported on the left side of the support base (3), and the rotation of the feed motor (rotation) , motor shaft (
From the first gear circle fixed to 40a), the second gear meshing with the first gear circle (42's large diameter gear part (42aJ), which is smaller in diameter than this large diameter gear part (42a) and is a large diameter gear part) A small diameter gear part (42b) that integrally constitutes the second gear (6), a third gear that meshes with this small diameter gear part (42b), a large diameter gear 5 (43a), and a small diameter gear part (43b). ), the large diameter gear part (44
a), a small diameter gear part (44b), a large diameter gear part (45a) of the fifth gear (blue) that meshes with this small diameter gear part, a small diameter gear part (45a),
5b) i diameter and is transmitted to the left drive gear unit which meshes with this small diameter gear portion (45b).

By the way, as shown in FIG. 14, a disc (rotation amount detection means) (9) is integrally formed on the first gear circle, and the motor shaft (40
It rotates together with the rotation of a). A black and white pattern of a white area (9a) that reflects light and a black area (9b) that does not reflect light is formed on this disk (9) over an angle of 180 degrees. On the other hand, the nine protruding pieces VC protruding from the left (iIIJ surface) of the support base t31 have two first and twenty-seventh angle sensors (rotation amount detection means) (15a) ( 15b) are fixed.These photosensors (15a) (15b) each have a pair of LEDs.
Reflective type 7 with exactly the same configuration and a built-in photodiode.
It is an otosensor, and as is clear from Figure 6, it is a disc; 9)
The white area (90 degrees
When facing the black area (9b), it receives the reflected light and outputs an H level, and when facing the black area (9b), it cannot receive the reflected light and outputs an L level output.

The aforementioned first and 27th Otosensors (15a) (15b)
The output is transmitted to a rotation amount detection circuit on a circuit board disposed on the royal chassis along with a lower lead-in SWH output (described later) via a line (not shown).

As shown in FIG. 11, the rotation amount detection circuit includes a phase comparison circuit kIII (120) that detects the phase relationship between the outputs of the first and twenty-seventh sensors (15a) (15b), and a phase comparison circuit Ij.
l! (120) A counter (121) that is controlled to count up or count down based on the output
It is made up of. In addition, the counter (121) uses the output of the 17th sensor (15a) as a count pulse,
It is reset by the output of the lower lead-in S to V (98), that is, it is reset at the timing when the lower lead-in SW (98) is turned on. The count value by this counter (121)K becomes the longitudinal position information of the pickup (31) with respect to the disk fl(l).

The right gear structure includes a sixth gear that is integrated with the fifth gear through an interlocking shaft 4η, and a sixth gear that is pivotally supported on the right side of the support base (3) so as to mesh with the fifth gear. It smells like drive gear four. The small diameter gear portion (45b) of the fifth gear and the sixth gear (4 main drive gear 4 and right drive gear 4 are designed to the same specifications, respectively, and the respective pivots of the left and right drive gears MH91 are , as shown in FIG. 3, are the same lines that pass through the center of the pickup and are orthogonal to the movement path of the pickup.

In FIG. 1, (140) and (141) are -2 for the left and right gears rotatably attached to the rotation shafts of the left and right drive gears 141f41, respectively. In addition, the support base (
3), a leading roller (104) is pivotally supported at the same height position as the right roller (141).

Dormitory mechanism felt't - consists of left and right guide rails (
51) and (52) are formed in the U-shape as mentioned above, but the left guide rail (51) has two side lines moving inside the dormitory 5 (A) and (B) and an arc-shaped dormitory as shown in No. 71g. Inside (C)
A left rack # (53) with which the left drive gear decoy of the self-propelled mechanism (4) engages is formed over the entire length of the arcuate dormitory interior (C) and both page line moving dormitory interiors (A ) (B), the left roller (140) of the support base (3)
A U-shaped left guide groove (55) into which the holder is fitted is formed.

On the other hand, the right roller (141) of the self-propelled mechanism (4) is attached to the right guide rail (52) over the entire length of both page line moving dormitory interior prisoners (B) and arcuate dormitory interior (Q) as shown in Figure 8. ) and the leading roller (104) are formed with a circular right guide groove (56) and extend over the entire length of the arc-shaped dormitory interior (C) and a part of both page line moving dormitory interiors (A) and (B). and support base (3
) is formed with a right rack portion (54) that engages with the right drive gear 4.

When the support base +3J is moved inside the lower linear dormitory for signal reproduction, it is transported by the drive of the left drive gear against the left rack part (53). At this time, the right roller (14
1) and the leading roller (104) are connected to the right guide groove (56)
When the student enters the dormitory, the slide groove (7) slides on the lower guide pole (61). Therefore, the support base +
Even if only the left drive gear is driven, the pickup (b) moves smoothly back and forth, and the pickup (b) moves accurately without deviating from the radius line of the disk αα.

After the playback from the inner circumference to the outer circumference of the lower surface of the disc is completed, when the playback starts from the upper surface, the support base (3) is moved from the lower guide ball (61
), and the left roller (140) moves into the left guide groove (
At the same time, the right drive gear 4 is fitted into the right rack section (
54).

Therefore, the support base (3) has three rollers (140) (
141) (104) are the respective guide grooves (55) (56).
) while inside the dormitory, both rack sections (53) (54)
By driving the dual drive gear decoy (6), the disc rises toward the upper surface of the disc along the arc-shaped interior (C) and is reversed, as shown in FIG. In this process, the support base (3) is not moved inside the dormitory by the guide poles, but since the plane drive gear [M drives the respective racks @ (53) and (54), it performs a reliable upward movement.

By further conveying the inverted support base (3) around the center of the disk, as shown by the two-dot chain line in FIG.
When the slide groove (to) is fitted into the upper guide ball (6), the left roller (140) and the right drive gear are removed from the left guide groove (55) and the right rack (54), respectively. Therefore, after that, the support base (3) is moved so that the right roller (141) and the leading roller (104) are moved into the dormitory by the right guide groove (56), and the slide groove (to) slides on the upper guide ball (8). At the same time, the disk (lO) is transported by the drive of the left VX* gear to the left rack part (53).
The signal reproduction on the top surface is performed from the inner circumference to the outer circumference. In this case as well, the support base (3) is the upper guide ball i6
) to move back and forth smoothly in the dormitory, and pick up 0υ
never deviates from the disk radius line.

As shown in Figure 1θ, at the lower and upper chassis elevations η, when the support base (3) reaches the inner circumferential side of the disk, there is a lower lead-in 5W (98 ) and an upper lead-in 5W (97) are provided, respectively. On the other hand, at the bottom of the support base (3), there is a ninth
As shown in the figure, protrusions (to) for operating both doi/5W (97,) (98) are formed.

Normal playback over both sides of the disk 1-[When the feed motor is activated], the support base (3) moves straight downward until it reaches the moving end of the prisoner inside the dormitory and turns the lower lead-in 5W (98).
The elVC is transmitted to return it to the initial position where it is turned to N, and at this position the feed motor output is reversed and the i! The disk is moved in the direction of 11riR, that is, from the inner circumference to the outer circumference of the disk (101) at a predetermined feed speed, and the lower side of the disk is reproduced.In addition, when reproducing this lower side, the spindle motor ?υ is Due to the rotation of the feed motor during this bottom surface regeneration, the first gear kick and the disc (9) rotate together in the clockwise direction in FIG.
15b) The output will be input to the phase comparison circuit (120) and the counter (121).

At this time, the first and 27th sensors (15a) (15b)
) The output has the phase relationship shown in FIG. 12(a). That is, due to the clockwise rotation of the disk (9), the output of the 17th sensor (15a) is advanced in phase by 90' compared to the output of the 27th sensor (15b). Phase comparator circuit (
120) detects this phase relationship and supplies an up command to the counter (121).

The lower lead-in 5W (98) of the counter (121) is ON.
It is reset when the above-mentioned up command is supplied, and counts up the pulses output from the first photo sensor (15a). Therefore, the count value of the counter (121) increases as the reproduction by the pickup Cυ progresses from the inner to the outer periphery of the lower surface of the disk αQ.

The count value of this counter (121) is input to the subsequent position substitution calculation circuit (122), and is used as position information in the disk radial direction, specifically, which side of the disk and how many cm from the center of the disk corresponds to the position. converted. Note that position information corresponding to each count value is stored in advance in the position substitution calculation circuit (122).

When the playback of the outermost 8 parts on the bottom side of the disc is completed,
The support base (3) is inside the arc-shaped dormitory (C)'! After i-
When the upward linear movement reaches the end of the movement inside the dormitory ('B), the up-doin SW (97) turns ON, and at this position, the feed motor (A) rotates in reverse, and the support base (3) faces the top surface of the disk. The disk moves from the inner circumference toward the outer circumference, and the top surface of the disk is reproduced from the inner circumference to the outer circumference.

Incidentally, during reproduction of the upper surface of the disk, the spindle motor 1) rotates in the opposite direction to that during reproduction of the lower surface.

Until the feed motor (a) is reversed when the upper lead-in SW (97) is turned on, the direction of rotation of the disc (9) is the same as during bottom surface regeneration, so the counter (121) is in a count-up state. ! lA, but the feed motor (
While the disk (a) is reversed and top surface regeneration is performed, the disc (9
) is also reversed, so the phase relationship between the outputs of the 1st and 27th sensors (15a) (15b) is as shown in Fig. 12 (
b). That is, the phase of the output of the 27th sensor (15b) is 9 compared to the output of the 17th sensor (15a).
The state is advanced by δ. The phase comparison circuit (120) detects this phase relationship and supplies a down command to the counter (121) ◇While this down command is being supplied, the counter (121) detects the pulse of the 17th auto sensor (15a) output count down. Therefore, as the reproduction by the pickup 3 progresses from the inner circumference to the outer circumference of the upper surface of the disc, the count value of the counter (121) becomes smaller. This count value is input to the position conversion circuit (122) and converted into position information as in the case of bottom side reproduction.

As mentioned above, the positional information obtained when the support base (3) moves across the lower and upper surfaces of the disk is usually obtained from the horizontal synchronization signal (Hsync) separated from the reproduced video signal and the reference signal from the reference signal generation circuit (124). is supplied to the spindle motor control circuit (123) that controls the rotation of the spindle servo shaft υ so that the frequency of the horizontal synchronization signal matches the reference signal, and the frequency of the horizontal synchronization signal is compared with that of the reference signal. If a horizontal synchronization signal cannot be retrieved due to a servo out, and it becomes temporarily impossible to control the rotation of υ of the spindle motor during CLV disc playback, this position information can be used instead of the servo using the horizontal synchronization signal described above. and execute rotation *J@ of the spindle motor circle.

At this time, in order to determine the rotational speed of the spindle motor (21) based on the position information, it is uniquely determined using the change curve shown in FIG. 13. The horizontal axis in FIG. 13 is the radial distance from the center of the disk to the pickup position, and is commonly used for both the top and bottom surfaces of the disk. However, as described above, the rotation directions of the spindle motor @kuru on the upper and lower surfaces of the disk are controlled to be in opposite directions.

Also, as mentioned above, the rotational speed of the feed motor (g) is increased compared to normal playback to perform high-speed playback, or when performing a high-speed search to search for an address at high speed in order to start playback from a desired address. It is possible to detect the positional information i and use it for spindle servo at the time of dropout. Therefore, due to the occurrence of dropout, the horizontal synchronizing signal cannot be outputted, causing disturbance in the spindle servo, and the occurrence of unstable operation of the spindle motor such as runaway rotation @ heavy normal rotation @ 傅 is prevented.

(G) Effects of the Invention As described above, according to the present invention, space can be saved by concentrating the position detection means on the movable base side, and even when both sides of the disc are played back by a single pickup, the position The detection means can be used in common, making it possible to reduce the number of parts. Furthermore, while maintaining highly accurate rotation control to the maximum extent possible, abnormal rotation of the spindle motor is prevented by executing rotation control based on position information only in abnormal situations where a synchronization signal cannot be obtained.

[Brief explanation of the drawing]

The drawings all relate to one embodiment of the present invention; Fig. 1 is a plan view showing the main parts of the pickup transfer device, Fig. 2 is a partially cut away perspective view of the same, and Fig. 3 is the position of the pickup and the dormitory mechanism relative to the disk. The fourth factor is a side view showing the inside of each dormitory mechanism, Figure 5 is a front view of the pick-up transfer device, fJG diagram is a left side view of the self-propelled mechanism, Figure 7 is a support pace and Figure 8 is a slope view showing the main parts of the dormitory mechanism, Figure 8 is a slope view of the equipment in Figure 7 seen from a different direction, Figure 9 is a slope view of the support space seen from the back, and Figure 1O is a slope view of a pair of lead-ins. Figure 11 is a circuit block diagram for calculating position information, Figure 12 is a timing chart, Figure 13 is a playback position and spindle motor rotation when recalibrating a CLV disc. FIG. 14, which is a diagram showing the relationship with the number, is an explanatory diagram of the main part of the rotation amount detection means. (101-...Disk, 3P...Pickup, Hit...Feed motor (drive motor), (Private...Left, right gear mechanism, (3)...Support pace (movable base)
, i91... Disc (rotation amount detection means), (15a)
(15b) - 1st and 27th sensor (rotation amount detection means), f51... Dormitory mechanism 0

Claims (2)

[Claims] (1) It has a pickup that reads information from a disk on which information is recorded on both sides, a drive motor, a plurality of gear mechanisms driven by the drive motor, and rotation amount detection means that detects the amount of rotation of the gear mechanisms, a movable base that supports the pickup and moves by the driving force of the drive motor; and means for moving the movable base within the dormitory so that the pickup can read information from both sides of the disk; A disc player characterized in that the position of the pickup in the radial direction with respect to the disc is detected from the amount of rotation detected by an amount detection means. (2) a pickup that reads information from the disk; a disk rotation control means that controls the rotational speed of the disk so that the frequency of a synchronization signal obtained from the information read by the pickup is always maintained at a predetermined value; A disc player comprising: a position detecting means for detecting a position of the pickup in a radial direction with respect to the disc, and in a state where the synchronization signal is not obtained, the rotation of the disc is controlled by the output of the position detecting means.