JP2550850B2 - Disc player - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc player which irradiates a disc surface on which information such as music is recorded with light and reproduces a signal by using the reflected light. In particular, the present invention relates to a disc player with little deterioration in the reproduced sound quality. FIG. 1 is a disc player capable of reproducing an optical disc, for example, a compact disc (hereinafter referred to as C
An example of holding a disc of a D player) is shown. The turntable 2 is fixed to the rotating shaft of the disc motor 5, and the disc 1 is sandwiched between the turntable 2 and the clamper 3. A magnet 4 is provided around the clamper 3. On the other hand, turntable 2
Is made of magnetic material. Therefore, the disc 1 can be fixed to the turntable 2 by the attractive force of the magnet 4 attached to the clamper 3. Reference numeral 6 denotes a pickup, which receives the reflected light from the disk 1 held on the turntable 2 to read out a signal. By the way, in the conventional disk holding device, as described above, since the turntable 2 and the clamper 3 having a diameter of about 30 mm hold only the central portion of the disk 1 having a diameter of 120 mm, a large sound pressure is exerted. It was found that the disc itself may vibrate due to the sound pressure reproduced by the speaker during reproduction, and the pickup may not be able to follow. Actually, the diameter is 120 mm and the plate thickness is 1.2 mm.
When an experiment was conducted using a commercially available compact disc made of a material mainly composed of polycarbonate, 700 to 8
At a frequency near 00 Hz, it was confirmed that the disc on the outer periphery of the clamp part generated vibration of a secondary mode having circular nodal lines as shown in FIG. The vibration state of the disk in this secondary mode is shown in FIG. 2, and the solid lines 1a, 1 with respect to the horizontal plane of the disk shown by the chain line
It vibrates as represented by b. Here, in the antinode of the secondary mode vibration of the compact disc, a portion 30 to 40 mm from the center of the disc is called a first antinode portion, and a peripheral portion of the disc is called a second antinode portion. Further, it has been found that the disk vibrates in various modes by changing the frequency in addition to the secondary mode. However, it has also been found that there is a particular problem during reproduction when the disk vibrates in the secondary mode having the above-mentioned circular nodal lines. As described above, when the disk itself vibrates due to the sound pressure, the focus and tracking servo are hindered, and when the degree is severe, a phenomenon such as sound interruption occurs and the hi-fi It was a major drawback as a device. In order to eliminate the above-mentioned drawbacks of the prior art, it is possible to suppress the resonance of the disk caused by the sound pressure by a supporting member of the disk having a diameter of 120 mm and perform high quality reproduction. To provide a player. According to the present invention, there is provided a circular disk support member which is pressed against the disk from a surface of the disk which is not an information reading surface, and which has first and second ring shapes. When the information recorded on the surface of the disc having a diameter of 120 mm is read by light and reproduced,
2 generated on the disc due to the frequency near 800Hz
The first antinode portion and the second antinode portion of the vibration in the next vibration mode are respectively referred to as the first and second antinodes of the disc support member.
The above-mentioned object is achieved by pressing with the ring-shaped portion. Further, the first and second ring-shaped portions are
It may be a damper member having elasticity. According to the above-mentioned constitution of the present invention, 700 to 800H
The first antinode portion and the second antinode portion of the vibration in the secondary vibration mode generated in the disk by the frequency near z are
Since the first and second ring-shaped portions of the disc supporting member are pressed respectively, vibration during disc reproduction can be effectively suppressed. Further, if the first and second ring-shaped portions are elastic damper members, the vibrations can be absorbed thereby, and thus the vibrations can be suppressed more preferably. Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows an embodiment of the present invention. In FIG. 3, 8 is a clamper, 9 is a viscoelastic material that absorbs vibrations of felt, rubber, etc. provided on the contact surface between the clamper 8 and the disk 1. It is a damper member composed of a body. Reference numerals other than the above indicate the same or equivalent items as in FIG. In the present embodiment, the clamper 8 is made to have the same size as the disk 1 and the contact portion with the disk 1 is formed by the damper member 9.
Vibration of the disc 1 can be suppressed. The damper member 9 is preferably arranged on the clamper 8 at the first antinode portion and the second antinode portion of the vibration shown in FIG. According to this embodiment, the clamper 8 is constructed so as to rotate together with the disc 1 during reproduction and press against the disc. Since the disc 1 is light, the vibration of the disc 1 can be suppressed only by making the clamper 8 slightly contact the disc 1. In the embodiment of FIG. 3, the pressing force of the clamper 8 against the disc 1 is generated by the ring-shaped magnet 4. The present invention relates to a disc player,
The above-mentioned disc supporting member can suppress the resonance of the disc due to the sound pressure, which is a drawback of the prior art, and perform high quality reproduction. That is, 700-8
The first antinode portion and the second antinode portion of the vibration in the secondary vibration mode generated in the disc due to the frequency of around 00 Hz are suppressed, and a damper member such as rubber or felt is provided at the portion where the circular disc support member is pressed. Since the vibration is absorbed by the disk, the vibration of the disk can be effectively suppressed. With such an effect, it is possible to provide a high-quality disc player in which sound quality is unlikely to be deteriorated due to sound pressure or the like particularly during reproduction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of a conventional disk holding device. FIG. 2 is an explanatory diagram of a vibration mode of a disc. FIG. 3 is a configuration diagram of an embodiment of the present invention. [Explanation of Codes] 1 ... Disc, 2 ... Turntable, 3 ... Clamper, 4
... magnet, 5 ... disk motor, 6 ... pickup, 8 ... clamper, 9 ... damper member.

Claims (1)

(57) [Claims] 1. In a device for reading information recorded on the surface of a disc by light and reproducing it, a disc motor for rotating the disc having a diameter of 120 mm and the disc motor fixed to the disc motor and capable of rotating the disc near the central portion thereof A turntable for supporting the disk, a pickup for receiving the reflected light of the light applied to the information recording surface of the disk, and a circular disk support pressed against the disk from a surface other than the information reading surface of the disk. A member, the disc supporting member having first and second ring-shaped portions pressed against the disc,
A first antinode portion of vibration in a secondary vibration mode generated in the disk at a frequency of around 00 to 800 Hz is pressed by the first ring-shaped portion, and a second antinode portion is pressed by the second ring-shaped portion. Thus, the disc player is characterized in that the disc supporting member is provided with a pressing force to suppress the vibration of the disc during reproduction. 2. The disc player according to claim 1, wherein the first and second ring-shaped portions are elastic damper members.