JPS6010361B2 - pick up device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a pickup device that further improves the fidelity in sound reproduction.

A pickup device installed in a record player consists of a head shell provided at the tip of a tone arm and a pickup cartridge fixed to the head shell, and plays back audio signals recorded on a record disc. The reproduction needle provided on this cartridge vibrates in response to the signal recorded when tracing the chord tone groove, and it is known that the cartridge itself also vibrates as a reaction. Then, as a result of the harmful signals caused by these vibrations being added to the bride signal and being reproduced, the quality of the reproduced sound is degraded. Therefore, in order to prevent mechanical vibration without increasing the total weight, it was considered to use a super hard material with a high density.

For example, a head shell using polycrystalline aluminum oxide was considered. The purpose of this is to strengthen the structure that supports the vibrating body and prevent mechanical vibrations as much as possible, and is extremely effective in reproducing midrange and bass frequencies. However, I was dissatisfied with the sound separation and stereo feel of Takane Castle. 1st
Surface Density Speed of Sound (Yoshis) Thermal Expansion Vertical Wave Transverse Wave (x10-6%) Aluminum 2.69 6.420 3.040 23chi
Tan 4.58 5.990 2.960 9
．． 4 Iron 7.86 5.950 3.240 12 Copper 8.96 5.010 3.270 16.7 Magnesium 1.74 5.770 3.050
25 Brass 8.6 4.7002.100 13
Zutesires 7.91 5.790 3.100 16
．． 4 Kibi Koto to Sai, 3-27 11-0.

〇6-200 2-6 Alumina 3.96 10.30
0 6.345 8 As a result of investigating the cause of this, it was found that these ultra-hard metal oxides or nitride crystals are made of conventionally commonly used metal materials such as aluminum, magnesium alloy, yellow steel, and stainless steel, as shown in Table 1. The transmission speed of sound waves is more than twice that of the previous one, and the loss inside and on the surface of the sound waves is very small. Reflect,
It is thought that the above-mentioned sound clarity and three-dimensional effect may be impaired by superimposition on the original vibration.
It exists not only in materials with a high transmission speed of sound waves, but also in cases where the shell is made of metal materials such as aluminum, magnesium alloy, yellow steel, and stainless steel.
It has been found that the reflection of sound wave vibrations within the shell has a significant negative effect on the reproduced sound. What is the invention?)
By focusing on this point, we have placed a vibration absorbing material in close contact with a part of the shell at a position different from the mounting surface of the cartridge, which effectively absorbs the harmful vibrations generated in the cartridge through the shell, resulting in extremely high fidelity. The present invention provides a pickup device with high performance.

To explain the present invention with reference to the drawings, FIG. 1 shows a rectangular head shell substrate 1 made of ultra-hard metal nitride made of a material whose main component is silicon nitride, etc., and a head shell substrate 1 that is closely attached to its mounting surface 2. In a pickup device comprising a fixed pickup cartridge 3, a terminal mounting portion 4 extending perpendicularly to one end of the substrate 1, and a terminal 5 firmly fixed to the terminal mounting portion 4, the cartridge 3 is fixed to the substrate 1. A mounting plate 7 extending laterally and integrally having a finger rest 8 is firmly attached by a pair of screws 6a and 6b.

A vibration absorber 9 is brought into close contact between the mounting plate of the finger rest 8 and the surface of the shell substrate 1. The vibration of the case constituting the cartridge 3 is diffused throughout the board 1 through the bottom surface where it is attached to the shell board 1. At this time, the bottom surface of the case is substantially expanded to cover the entire area of the shell substrate 1.
Then, the vibration energy is collided and absorbed by the vibration absorber 9 provided on the surface of the substrate 1, and the magnitude of the absorption loss at this time is determined by the vibration transmitted through the shell material. The state is proportional to the speed, that is, approximately the square of the speed of sound. Therefore, since the shell substrate 1 is made of a material with a high sound velocity, harmful vibrations diffused through the substrate 1 are absorbed and attenuated most effectively. In this case, it is important that the contact surface between the case part of the cartridge 3 and the shell substrate 1 be in a state that does not impair vibration transmission, that is, a state with small vibration loss.
Therefore, in the above-mentioned pickup device, the drawbacks of the above-mentioned high-pitched and medium-pitched sounds can be effectively solved. FIG. 2 shows another embodiment of the present invention, in which a cartridge 3 is fixed to a mounting surface 2 of a head shell substrate 1 made of a crystalline body. Adhering the body 9 or similarly adhering the absorber 9a to the end face of the terminal attachment portion 4 is sufficiently effective.

The absorber 9 used in the above-mentioned pickup device is, for example, a hardened composition mainly composed of polydiorganosiloxane having an average molecular weight of 15,000 or more and inorganic fine powder, and preferably has a hardness of 8 to 3. Good characteristics include those with stem strength.

However, the thickness, volume, and hardness of the absorber 9 have an important relationship with the acoustic characteristics it absorbs, so it is desirable to adjust them to optimal values. This absorbent body 9 has extremely good adsorption properties to the sufficiently smooth surface of the shell, giving the best results compared to other rubbery absorbent bodies, and can withstand a wide range of room temperature changes. Almost its vibration absorption properties remained unchanged. As described above, according to the present invention, unnecessary harmful vibrations generated in the cartridge portion are effectively transmitted and diffused to the shell substrate portion, and the vibrations are absorbed by the vibration absorber provided for the substrate. Effectively absorbed and attenuated.

In this case, the sound velocity of the shell substrate is extremely high, and unnecessary vibrations in the cartridge portion are effectively transmitted and diffused to the shell substrate, so the absorption loss is extremely large. , the effect of absorbing and removing the unnecessary vibrations is great, and unnecessary vibrations no longer exist in the cartridge and shell portions. therefore,
Since the cartridge section detects the signal recorded in the chord sound groove with high fidelity, extremely excellent reproduction acoustic characteristics can be obtained. This effect can be effectively obtained even when the shell is made of a metal material such as aluminum, but the effect is further enhanced when a metal oxide or nitride crystal is used as shown in the example. be done.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a pickup device according to an embodiment of the invention, and FIG. 2 is a diagram showing another embodiment of the invention. 1...Head shell, 2...Mounting surface, 3.
...Power cartridge, 4... Machine mounting part,
5...Terminal, 7...Mounting plate, 8...
...Finger rest, 9...Vibration absorber. Figure 1 Figure 2

Claims (1)

[Claims] 1. A head shell substrate made of ultra-hard metal nitride that has a high acoustic vibration transmission speed, a pick-up cartridge cartridge closely fixed to this substrate, and harmful substances generated in the cartridge that are closely attached to a part of the shell substrate surface and passed through the shell. A pick-up device characterized by comprising a vibration absorber that absorbs vibrations.