GB2137797A - Dual mode disc player - Google Patents

Abstract

A disc player comprises a first drive (104) for driving a first turntable (105) for a first kind of an information- recorded disc (e.g. video), a second drive (106) for driving a second turntable (108) for a second kind of an information-recorded disc (e.g. audio), a single holder (109) for holding thereon the first and second drives, a holder drive (112) for driving the holder, and a pickup (114) for reading the first and second kinds of information- recorded discs at a predetermined play position. The single holder is moved so that a selected one of the first and second kinds of information-recorded disc is selectively positioned at the predetermined play position. An alternative embodiment is detailed (Figs. 2-4) with internal gear (9), springs (10a, b) biassing racks (12a, b), and adjusting screws (13a, b), which counters vibration, misalignment etc. Friction wheels or plates may replace the gears. Three or more spindle motors may be used. <IMAGE>

Description

SPECIFICATION Dual mode disc player The present invention relates to an informationrecorded disc player which is capable of playing both audio and video discs by means of a single pickup and more particularly to a disc player which is capable of locating a plurality of spindle motors with high accuracy.

In the prior art, there has not been proposed a system which can play both an audio disc and a video disc by means of a single pickup, and different player systems are required for the two types of discs.

More specifically, in a compact disc player (which will be referred to as "CD") or an optical type video disc player (which will be referred to as "LD"), alabel indicating the content of the play has to be viewed by the operator (i.e., the upper disc side when the disc is played in a horizontal position), and the signals are desired to be read out from the lower side of the disc if automatic disc-loading or clamping operations are desired.

However, the inventors have appreciated that in a compatible player which is capable of playing the two discs (i.e., in which the centres of rotation for playing the two discs are common and in which a pickup is commonly used), the clamping area of the LD and the read-in of the CD are overlapped making it necessary to interchange the turntables.

According to one aspect of the invention, an information-recorded disc player is characterized in that a rotary drive for a video disc and a rotary drive for an audio disc are attached to a single holder; in that one of the rotary drives is brought to a playing position by turning the holder; and in that a single pickup is disposed in the playing position, whereby the two discs are selectively played by the single pickup.

The present invention has an object a disc player which can alternately fix a plurality of spindle motors in a predetermined position with high accuracy.

According to a second aspect of the present invention, there is provided a disc player comprising first drive means for driving a first turntable for a first kind of an informationrecorded disc, second drive means for driving a second turntable for a second kind of an information-recorded disc, a single holder means for holding thereon the first and second drive means, holder drive means for driving the holder means, pickup means for reproducing a signal from one of the first and second kinds of information-recorded discs at a predetermined play position, and means for moving the single holder means and for locating the single holder means so that one of the first and second kinds of information-recorded disc is selectively positioned at the predetermined play position.

In one construction the first drive means has a spindle and a motor, the second drive means has a spindle and a motor, the holder drive means is arranged to move the holder means through a predetermined range, and the disc player further comprises a pair of moveable members provided in the vicinities of the ends of the predetermined range and means for biasing the moveable members to move in opposite directions to a centre of the predetermined range.

The present invention will now be described by way of example with reference to the accompanying drawings, in which:~ Figure 1 is a diagrammatic side view showing part of one disc player; Figure 2 is a plan showing a spindle motor interchanging device of a second disc player; and, Figures 3, 4(A) and 4(B) are partial side views of the disc player shown in Figure 2.

Figure 1 is a sectional view showing an information-recorded disc player, in which reference numerals 101 and 102 indicate a video disc and an audio disc. A rotary drive 103 for the video disc 101 includes a spindle motor 104 and a turntable 105. A rotary drive 106 for the audio disc 102, includes a spindle motor 107 and a turntable 108. Incidentally, disc clamps are omitted from both the rotary drives 103 and 106.

Indicated at numeral 109 is a motor holder which has a shaft 109a protruding from the centre thereof. This shaft 109a is rotatably borne by means of a bearing 110 and is connected throught a reduction gear 111 to a turning motor 112. The motor holder 109 has its one end mounting the rotary drive 103 of the video disc 101 and its other end mounting the rotary drive 106 of the audio disc 102. Furthermore, the motor holder 109 has a double bend at an angle of inclination and the mounting angle of its shaft 109a is such that one of the rotary drives 103 or 106 may, by turning the holder through 1 80c, replace the other drive at a horizontal play position at the centre of a decorative plate 11 3, the turntable 105 or 108 slightly protruding from the decorative plate 11 3.

A pickup 114 is so arranged in the aforementioned play position that it can move radially of the two discs 101 and 102. If the two discs 101 and 102 are of the contactless optical type, the pickup 114 is an optical type, and if the discs 101 and 102 are of the electrostatic capacity type, it is an electrostatic capacity type.

Indicated at numeral 11 5 is a cabinet to which a hood 116 is hinged at 117 so that it can be opened and closed. Numeral 118 indicates a select button for determining which of the rotary drives 103 or 106 should be used. This select button 11 8 is set so that it can operate when the hood 11 6 is in its open state.

This player operates as follows. At first, the hood 116 is opened, and the select button 118 is depressed. If necessary, the drive motor 11 2 than rotates to transmit its turning force through the reduction gear 111 to the shaft 109a. The motor holder 109 is thus turned by 1 800 on its shaft 109a so that the desired rotary drive 103 or 106 comes to the play position whereas the other rotary drive 103 or 106 comes below the decorative plate 113. Next, the turntable 105 or 108 of the rotary drive 103 or 106 receives the video disc 101 or the audio disc 102 which is loaded in the play position.After this, the hood 116 is closed to establish the play state, in which the pickup 114 runs from the innermost signal path to the outermost one of the video disc 101 or the audio disc 102 thereby to read out the information signal recorded in the disc 101 or 102.

Figure 1 shows a player of the top-loading type but the invention is applicable to a front loading type. As means for selecting the. two rotary driver 103 and 106, the select button 118 may be replaced by an automatic detecting mechanism such as a light-receiving element.

The motor holder 109 is turned by 1800 but this angle need not be limited to 1800. It is sufficient that one or other rotary driver 103 or 106 comes below the decorative place 11 3 in the case of the top loading type. For the same reasoning, the angle of inclination of the motor holder 109 may be suitably determined. In Figure 1, the motor holder 109 is turned at a fixed position, i.e., on its shaft 109a. However, one rotary drive 103 or 106 may be brought to the play position by turning the motor holder 109 after the holder 109 has been lowered, and than lifting the holder 109 up again.

As has been described hereinbefore, the rotary drive 103 for the video disc 101 and the rotary drive 106 for the audio disc 102 are attached to the single holder 109 such that one rotary drive 103 or 106 can be brought to the playing position by turning the holder 109, and the single pickup is disposed in the playing position so that both the video disc 101 and the audio disc 102 can be selectively played by means of the single pickup 1 14. Since the two rotary drives 103 and 106 and the single pickup 1 14 are integrated, the disc player can as a whole be small in size.

Figures 2 to 4 shows another example of player having a mechanism in which motor mounting tables respectively having special spindle motors fixed thereon are swingable to change the motors.

The positioning of the spindle motors has to be accurate, and neither vibration nor misalignment is allowed during an eccentric disc play (e.g., an unbalanced force of 1.5 N is allowed for the LD standards).

For this purpose, it is necessary to satisfy the following conditions: (1) The positioning is simple to adjust and is accurately reproducible.

(2) At the play positions, the spindle motors fixed with their rocking mechanism and their drive mechanism having their loosenesses and backlashes absorbed.

(3) These conditions (1) and (2) are satisfied for both the spindle motors.

In Figures 2 to 4, an axis Z provides a redetermined position for the spindle motors. A motor mounting table 2 is so attached to a chassis 1, acting as a base, that it can rock or swing about a pin 3. In other words, the motor mounting table 2 has a generally sector shape which has its base portion hinged to the pin 3 fixed to the chassis 1.

The motor mounting table 2 is formed with spindle motor mounting top faces 2a and 2b, on which afe respectively fixed spindle motors 4a and 4b.

On the chassis 1, there is mounted a drive motor 5. To this drive motor 5, there is attached a worm gear 6. The worm gear 6 meshes with the worm wheel 8a of a gear 8 which together with the worm gear 6, constitutes the speed-reducing means.

That gear 8 is rotatably borne on a gear shaft 7.

This gear shaft 7 is fixed to the chassis 1. The gear 8 is formed with a spur gear 8b, which is adapted to come into engagement with racks 12a and 12b as the motor mounting table 2 turns on the pin 3.

An internal gear 9 is fixed on the side 2c of the motor mounting table 2. To both ends of that side 2c, there are fixed the respective ends of tension springs 1 0a and 1 orb.

Thus, as the motor mounting table 2 turns about the pin 3, as described above, the spur gear portion 8b of the gear 8 comes into meshing engagement with the racks 12a and 12b which are biased outward by the action of the tension springs 1 0a and 1 Ob and made slideable along guides 11 a and 11 b.

To the side 2c of the motor mounting table 2, there are attached adjusting screws 13a and 13b.

Onto these adjusting screws 13a and 13b, there are pressed the racks 12a and 12b which are biased by the tension springs 1 Oa and 1 Ob.

To the side of the motor mounting table 2, there are attached drive stop switches 14a and 14b, and positioning pins 15a and 1 Sb. These positioning pins 15a and 15b are adapted to abut against stops 16a and 16b, which are attached to the chassis 1, so that spindle motors 4a and 4b may be fixed in predetermined positions.

The operations of this disc player will now be explained.

Figure 3 shows the state in which the spindle motor 4a is fixed on the axis Z.

First of all, when the drive motor 5 is actuated, the drive force of the motor 5 is transmitted to the worm gear 6, the gear 8 and the rack 12a so that the spindle motor mounting table 2 is turned on the pin 3 in the direction of arrow a.

As is apparent from Figure 4(A), moreover, if the tooth shape of the overlapped portions of the racks 12a and 12b and the internal gear 9 are identically treated by the adjusting screws 13a and 13b, the gear 8 meshes with the rack 12a, the internal gear 9 and the rack 12b in this order.

If the motor mounting table 2 further turns in the direction of arrow a so that the positioning pin 15a abuts against the stop 16a, as shown in Figure 4(A), the motor mounting table 2 is stopped so that the spindle motor 4b comes into alignment with the axis Z.

Since the drive motor 5 continues its rotation, moreover, the rack 12b, which has been biased in the direction of arrow b in Figure 4(B) by the tension spring 1 Ob, is slid in the direction of arrow c in Figure 4(B). When the drive motor stop switch 14b depressed, the rotation of the drive motor 5 is stopped to interrupt the rack 12b.

This is state in which the motor mounting table 2 is forced to contact the stop 1 6a by the tension of the tension spring 1 Ob.

In the Figures 2 to 4 example, the pin hinging the motor mounting table 2 rocks about a horizontal axis fixed horizontally at the chassis 1.

However, the spindle motors may rotate about a vertical axis, move in a horizontal direction or reciprocate along other various paths.

The driven gear is exemplified by the combination of the-internal gear 9 and the racks 12a and 12b but a gear having another shape in accordance with the aforementioned paths may alternatively be used.

Furthermore, the drive motor 5 is mounted on the chassis 1, whereas the driven gear is attached to the motor mounting table 2 of the spindle motors, but this arrangement may be inverted.

The gears are used as the driving power transmitting means, but friction wheels or plates may be used if the frictional forces are sufficiently obtained.

The invention is exemplified in the illustrated examples by the case in which the spindle motors used are two in number, but three or more spindle motors may be used.

As described above, the rack is divided into plural parts so that the spindle motors can be fixed at both the ends of the paths of their reciprocal motions.

Moreover, not only the back-lash of the gear but also the looseness due to the dimensional errors of the respective members can be absorbed, and the shocks when the positioning pins abut the stops can be absorbed, because the racks are mounted through the springs. As a result, the spindle motors can be interchanged at a high speed in a short time.

Still moreover, even if the drive motor is stopped with the positioning pins in reliable abutment against the stops, no load is applied to the motor and other members, with resultant effect that the positioning operations can be accurately conducted.

Claims (14)

1. A disc player comprising first drive means for driving a first turntable for a first kind of an information-recorded disc; second drive means for driving a second turntable for a second kind of an information-recorded disc; a single holder means for holding thereon the first and second drive means: pickup means for reading the first and second kinds of information-recorded disc at a predetermined play position; and means for moving the single holder means and for locating the single holder means so that a selected one of the first and second turntables is selectively positioned at the play position.

2. A disc player according to claim 1, wherein the single holder means has a rotational axis around which the single holder means can be turned through a predetermined angle to change over the first and second turntable of the play position.

3. A disc player according to claim 2, wherein the predetermined angle is substantially 1 800.

4. A disc player according to claim 2 or claim 3, wherein the rotational axis of the holder means is inclined to the vertical.

5. A disc player according to claim 1, wherein the holder means is swingable about a predetermined axis.

6. A disc player according to claim 5, wherein the first drive means has a spindle and a motor and the second drive means has a spindle and a motor, the holder moving means being arranged to move the holder means through a predetermined range; and there are a pair of movable members provided in the vicinities of the ends of the predetermined range and means for biasing the movable members to move in opposite directions to a centre of the predetermined range.

7. A disc player according to claim 6, wherein the holder moving means including an arcurate rack, and an output pinion engaging the arcurate rack.

8. A disc player according to claim 7, wherein each of the movable members has a rack portion engaging the output pinion.

9. A disc player according to claim 8, including means for adjusting a position of the rack portion relatively to the arcurate rack of the holder means.

10. A disc player according to claim 9, further including positioner means for detecting positions of the movable members.

11. A disc player according to any one of claims 7 to 1 0, wherein a rotational axis of the output pinion is located on a predetermined stationary line.

12. A disc player according to any one of the claims 6 to 11, wherein each of the movable members is guided by guide means.

13. A disc player according to any one of claims 6 to 12, wherein the means for moving and locating the holder means includes stationary stop members abutting against the holder means.

14. A disc player, substantially as described with reference to Figure 1, or to Figures 2 to 4, of the accompanying drawings.