JPH0542043B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a method for manufacturing a turntable on which an information recording disc (hereinafter referred to as a disc) is mounted in an information signal reproducing device such as a video disc player. .

2. Description of the Related Art Generally, an information signal reproducing device includes a rotary drive unit that supports and rotates a disk, a detection unit that detects a signal from the disk, a signal processing unit that further converts the detected signal, and a movement of the detection unit. It consists of a mechanical section that raises and lowers the disk, etc.

FIGS. 5 and 6 show the overall configuration of an example of an information signal reproducing apparatus, and FIG. 7 shows the configuration of a signal detecting section of the information signal reproducing apparatus. In this example, a needle-contact type video disc player is used, and the turntable is constructed using a conventional type. First, in FIGS. 5 and 6, 1 is a turntable, 2 is a disk, 3 is a center boss, 4 is a cartridge, 5 is a detection circuit, 6 is an arm, 7 is a clamp, 8 is a roller, 9 is a shaft, and 10 is leg, 1
1 is a chassis, and 12 is a motor. In FIG. 7, 14 is a needle, 15 is a lead, 16 is a cantilever, and 17 is a suspension. Furthermore, Figure 8,
FIG. 9 shows an example of a conventional turntable 1.

Conventionally, the turntable 1 is often a die-cast or resin-molded product, and its structure has a flange surface 1a for attaching to a rotation drive device (motor) and a hole 1b for centering, and has a disc-shaped expanded disc. On the upper surface, a support surface 1c having a certain width necessary for supporting the disk 2 is formed concentrically at the outer and inner circumferences. On the other hand, the disk 2 is formed with concentric circles on the outer and inner sides of the area where the signal is recorded (signal surface), which are higher than the signal surface. It is supported on the bearing surface 1c. The disk 2 is placed on the turntable 1 while being centered by the center boss 3, and the closeness of the disk 2 to the turntable 1 is increased by pressurizing the vicinity of the center hole 1b.

Problems to be Solved by the Invention Most disks are mainly made of resin material, and they themselves have waviness (face runout) in the thickness direction, and if there is excessive face runout on the signal surface, the signal detector will not follow the disk. becomes impossible, which will impede playback. Although it depends on the frequency response characteristics of the detector, in general, if the surface runout has the same amplitude, the higher the frequency, the more likely it is to interfere with reproduction. On the other hand, when the entire reproduction apparatus is vibrated or an external impact is applied, these forces or vibrations are propagated to the disk, increasing the amount of surface runout. Conventionally, a turntable is a rigid body integrally formed of metal or resin, which easily propagates vibrations and shocks applied from the outside, and the natural frequency of the vibration generated in the turntable itself is the unique frequency of the disk. higher than the frequency. If the disk is warped and the outer periphery is only partially in contact with the support surface of the turntable, or if the pressing force near the center hole is not sufficient on the outer periphery, The high-frequency vibrations of the turntable generated by the vibrations and shocks applied by the turntable are transmitted to the disk, where they appear as large-amplitude vibrations. Conversely, the vibrations generated in the disk also become violent due to the reaction from the turntable. In other words, the disc and turntable interfere with each other, especially at the outer periphery, and high-frequency and large-amplitude vibrations are applied to the disc, which, together with the surface runout of the disc itself, limits the tracking of the detector. Exceeding this will cause problems with playback. In particular, in the case of a needle contact type information signal reproducing device, needle skipping (the needle bouncing on the signal surface) may occur, which may damage the disk. Depending on the extent of this damage, the signal may be completely lost, or new damage may occur when the needle passes through the damaged area again.

When an integrally formed rigid turntable is used, as in the conventional example described above, it is vulnerable to vibrations and shocks applied from the outside, which tends to impede good playback.

In addition, the disk support surface of the turntable is a relatively smooth surface in conventional examples, and when the motor rotation rapidly rises or falls, the disk slides on the turntable, making the support unstable and causing abnormalities. It will also generate sound.

The present invention solves the above-mentioned problems and provides a manufacturing method that can easily manufacture a turntable that has a structure that increases the supporting capacity of the disk, has particularly strong resistance to external vibrations and shocks, and has a structure that prevents the disk from slipping. It provides:

Means for Solving the Problems In order to achieve the above object, the turntable manufacturing method of the present invention includes a base body made of a hard material and an outer edge member made of a soft material on the outer edge of the base body. The turntable is manufactured by using a mold that sandwiches the upper and lower surfaces of the outer periphery of the base to form a sealed space at the outer edge of the base, and fills this space with a soft material to close the outer edge of the base. A soft member is formed in the portion.

Effect With the above-described configuration, it is possible to realize a turntable in which a soft member is formed on the outer edge of a hard member.
When this turntable is used, the outer periphery of the disk is supported by the soft member (outer edge member) of the turntable, which acts as a buffer and prevents vibrations and shocks applied from the outside from being transferred from the turntable to the disk. It is difficult for the signal to propagate, and interference between the turntable and the disk is reduced.

Embodiment Hereinafter, a method for manufacturing a turntable according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing the structure of an embodiment of the manufacturing method of the present invention, FIG. 2 is a plan view showing an embodiment of the turntable according to the present invention, and FIG. The X sectional view and FIG. 4 are views showing a state in which a disk is placed on the same turntable. In the figure, 1
3 is a base formed of a hard material (die cast or hard resin), and a rotary drive device (motor)
It has a flange surface 13a for mounting on the disk and a hole 13b for centering, and a support surface 13c with a certain width necessary for supporting the inner circumference of the disk is concentrically formed on the upper surface of the expanded disk. Reference surfaces 13d and 13e necessary for forming an outer edge member 14, which will be described later, are formed concentrically on the upper and lower surfaces of the board.

The reference surface 13d is a surface having the same height as the disk support surface on the outer peripheral side of a conventional turntable, and the reference surface 13e formed on the back side has a certain thickness accuracy with respect to the reference surface 13d on the front side. I'm keeping it.

Reference numeral 14 denotes an outer edge member made of a soft material (rubber, thermoplastic elastomer, etc.), and surfaces 14a and 14b having the same height as reference surfaces 13d and 13e at the outer edge of the base body 13 form concentric circles with a constant width. It is formed. The surface 14a of the outer edge member 14 is a surface for supporting the outer peripheral side of the disk, and is therefore formed on the same surface as the reference surface 13d of the base body 13.

This outer edge member 14 is molded using molds 18a and 18b as shown in FIG. The upper mold 18a and the lower mold 18b of the mold are in close contact with each other and also with the reference surfaces 13d and 13e of the base body 13, respectively, and form a sealed space for molding the outer edge member 14. A soft material (for example, thermoplastic elastomer) is injected into this space through the runner 19 to form the outer edge member 14. In forming the outer edge member 14, the base body 13 has a further expanded portion 13f on the outer periphery, and this expanded portion 13f is partially provided with holes 13g. 14 is provided with the function of mechanically fixing it.

The disk 2 is placed on a turntable 13 as shown in FIG. 4, and the outer periphery of the disk 2 is supported on an outer edge member 14. Surface 1 of outer edge member 14
4a is formed with fine irregularities or fine knurlings formed radially, and also functions to prevent the disk 2 from slipping.

As described above, according to this embodiment, the soft outer edge member 14 is attached to the outer edge of the base body 13 formed of a hard material.
can be easily formed, and the mounting surface 14a of the disk 2 can maintain the same accuracy as the reference surface 13d of the base body.

By using this turntable, the turntable and disk are less likely to interfere with each other due to external forces on the outer periphery, and the propagation of vibrations and shocks from the turntable to the disk can be reduced. . The anti-slip provided on the support surface of the outer edge member can prevent the disk from slipping due to rapid rises and falls of rotation.

Effects of the Invention As described above, the present invention can easily produce a turntable having a soft outer edge member with precision by using a mold that holds a disc-shaped base body and fills and molds a soft material into the outer edge part. Well-manufactured, this turntable increases the bearing capacity of the disk, particularly increases its resistance to external vibrations and shocks, and also prevents the disk from slipping, greatly increasing the stability of signal reproduction. can.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view showing the structure of an embodiment of the turntable manufacturing method of the present invention, and FIG. 2 is a plan view showing an embodiment of the turntable according to the present invention.
3 is a sectional view taken along the line XX in FIG. 2, FIG. 4 is a sectional view showing a state in which a disk is placed on a turntable according to an embodiment of the present invention, and FIG. 5 is an information signal reproduction according to the present invention. A plan view showing an example of the device, FIG.
7 is a perspective view showing the configuration of the signal detection section of the information reproducing apparatus, FIG. 8 is a plan view showing a conventional turntable, and FIG. 9 is a Y-- It is a sectional view taken along the Y arrow. 2... Information recording disk (disk), 13... Base body, 14... Outer edge member, 18a, 18b... Molding mold.

Claims (1)

[Claims] 1 For a disk-shaped base made of hard material,
A mold is provided to sandwich the upper and lower surfaces of the outer periphery of the base body to form a sealed space at the outer edge of the base body, and this space is filled with a soft material to form an outer edge member made of the soft material on the outer edge of the base body. A method of manufacturing a turntable, comprising: