JPS59191101A - Turntable - Google Patents

Abstract

PURPOSE:To improve the rigidity of a turntable through its geometric effect without changing the weight and material by constituting the turntable so that it inclines toward the recording disk placing surface side from the central part to the outer periphery. CONSTITUTION:A turntable 21 is formed in such a way that it inclines, for example, linearly toward the recording disk placing surface 213 side from the central part 211 to the outer periphery 212. Therefore, the outer periphery 212 becomes higher in elevation than the central part 211. Moreover, in this case, the inclination of the tapered surface 214 at the recording disk placing surface side 213 is set so that it becomes smaller than the inclination of the tapered surface 216 of the opposite side 215. As a result, the thickness t2 of the outer periphery 212 of the turntable 21 is thinner than that t1 of the inner peripheral part 211. The turntable 21 is equipped with ribs 217 and 218 at the central part 211 and outer periphery 212 to support the non-signal part of a recording disk. Therefore, the moment of inertia is overlapped and rising time of the turntable can be made faster.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a turntable that supports and rotates a video disc or an audio record in a video disc player, audio player, or the like.

[Technical background of the invention]

In recording disc playback devices such as video disc players and audio players, the recording disc is generally supported by a turntable and driven to rotate. FIG. 1 is a sectional view showing a conventional turntable. In the figure,
11 is a turntable, and 12 is a recording disk placed on this turntable. The turntable 11 has ribs 113 and 114 on a central portion 111 and an outer peripheral portion 112, respectively. The ribs 113° and 114 K are designed to support the non-signal portion 121 at the center and the non-signal portion 122 at the outer portion of the recording disk 12. Such a turntable is attached to a rotating shaft 13 of a motor or the like via a sub-turntable 14, and is driven to rotate at a predetermined number of rotations. Incidentally, it is known that warping occurs in recording disks due to distortion during manufacturing or storage. Second
When the recording disc 12 with the warp as shown in the figure is placed on the turntable 11, the outer circumference 1 of the turntable 1
12 causes a deflection 0) as shown in FIG. 3 due to a concentrated load. To explain with a specific example, as shown in FIG. 4, the inner diameter of the rib 113 is 36mm, the outer diameter is 38mm, and the rib 114
The inner diameter of the turntable 11 is 127.25 mm, the outer diameter is 129.25 mm, and the inner thickness of the main body of the turntable 11 is 2.5 mm. Jbu114
Consider a turntable 1 with a wall thickness of 5W.

If a load of 140 # is applied to the rib 114 of such a turtle 11, the outer peripheral portion 112 has a thickness of approximately 81 μm.
A deflection (,) occurs. However, this is done using the finite element method (SA
P-V) has 26 three-dimensional elements and 16 nodes.
2. Also, Young's modulus is 800 kl? /WR2(7) case. This deflection ←) affects the follow-up characteristics of Cartlitz, so it needs to be minimized as much as possible.

Conventionally, in order to reduce this deflection (X), methods have been taken to increase the thickness of the main body portion of the turntable 11 or to improve the rigidity by using a material with a high Young's modulus.

[Problems with background technology]

However, in the case of the above-mentioned conventional methods, the weight of the turntable 11 increases, and (1) the moment of inertia increases. The time taken will be longer. (2) The load on the motor increases and the reliability of the motor decreases. (3) The turntable 11 had drawbacks such as an increase in manufacturing costs.

[Purpose of the invention]

The present invention has been made to address the above-mentioned circumstances, and an object of the present invention is to provide a turntable whose rigidity can be improved through shape effects while maintaining the same weight and materials as conventional turntables.

[Summary of the invention]

In this invention, the turntable is configured to be inclined toward the recording disk mounting surface from the center toward the outer periphery.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 5 is a side view showing only half of the turntable 21 of one embodiment in section. In the figure, the entire turntable 21/li is formed into a bowl shape.

That is, the turntable 21 is formed so as to be inclined, for example, linearly, from a central portion 211 toward an outer peripheral portion 212 toward a mounting surface 213 for a recording disk (not shown). As a result, the outer peripheral part 21'2 becomes the central part 211.
It's getting really expensive. Further, in this case, the inclination of the tapered surface 214 on the side of the mounting surface 213 of the recording disk is set to be smaller than the inclination of the tapered surface 216 on the surface 215 on the opposite side to the mounting surface 213. In this case, the wall thickness t2 of the outer peripheral portion 212 of the turntable 21 is the wall thickness t of the inner peripheral portion 211.
y, it's getting smaller. The turntable 21 further has lips 217921B on its center portion 211 and outer peripheral portion 212, respectively, for supporting the non-signal portion of the recording disk.

FIG. 6 shows the dimensions of each part when the turntable shown in FIG. 5 is designed in accordance with the specifications of the turntable 11 shown in FIG. 4. The inner and outer diameters of the ribs 217 and 218 are the same as those shown in FIG. 3 above. The wall thickness of the main body portion is 3 run at the center part 211 and 2.1 run at the outer peripheral part 212. In addition, the surface 215 and the tapered surface 21
The distance between the surface 215 and the vicinity of the outer peripheral part 212 of 6 is 1.9 raa, the distance between the surface 215 and the upper surface of the lip 218 in the figure is 5 mm,
! The height of Jbu218 is 1 question.

According to the turntable 21 having the above structure, the rigidity of the turntable 21 can be improved while using the same material and the same weight as the conventional turntable 1. This will be explained below based on the following table. The table compares the turntable 11 of FIG. 4 with the turntable of FIG. 6 in terms of weight, moment of inertia, etc.

However, the number of three-dimensional elements based on the finite element method (5AP-V) is 26. Number of nodes: 108, boundary g-prime, number of elements: 54.
Number of nodes: 54 Material data: Young's modulus: 800 Yu/Hidden 2. Specific gravity: 1.43° Poisson's ratio: 0.3 As described above, according to the turn tape A2 of this embodiment, the moment of inertia can be reduced by 93%2 compared to the conventional turntable 11, even though it has the same weight and the same material. The amount of deflection due to own weight can be reduced by 46%, and the amount of deflection due to a load of 140 g can be reduced by over 56%. In other words, the same weight and material as before! , i can increase the rigidity, so the turntable 2 does not become heavy, and (1) the moment of inertia is superimposed, making it possible to hasten the start-up time of the turntable. (2) The load on the motor is reduced and the reliability of the motor can be improved. (3) Reducing manufacturing costs brings about advantages such as sharpness.

In the previous embodiment, the case of linearly tilting was described, but it goes without saying that it may also be, for example, arcuately tilting.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a turntable that can improve rigidity due to the shape effect while maintaining the same weight and materials as conventional ones.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing a conventional turntable, Fig. 2 is a cross-sectional view showing a state in which a recording disc has warped, Fig. 3 is a cross-sectional view to explain the drawbacks of the conventional turntable, 4
The figure is a cross-sectional view for explaining the drawbacks of a conventional turntable according to specific specifications, FIG. 5 is a side view showing an embodiment of the turntable according to the present invention, and FIG. 6 is a turntable shown in FIG. FIG. 3 is a sectional view showing specific specifications of the table. 21... Turntable, 211... Center part, 21
2... Outer peripheral part, 213... Recording disc mounting surface, 21
4... Qi 9th surface, 2J5... Surface opposite to the mounting surface, 216... Tapered surface, 217, 218... Rib. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 @ Figure 2 Figure 3 Figure 5 Flash Figure 6

Claims (1)

[Claims] A turntable characterized in that the turntable is configured to be inclined toward a recording disk mounting surface from the center toward the outer periphery.