JP2022011455A - Pickup cartridge - Google Patents

Abstract

To provide a pickup cartridge that picks up needle vibration with a microphone and improves productivity of a sound pressure conversion type pick up cartridges, and improves sound quality.SOLUTION: A pickup cartridge includes a pickup element 2-12 shown in the selective diagram that is provided on a surface facing an analog record and picks up vibration from the analog record in a state where a cartridge base member to be attached to a tone arm is attached to the tone arm. The pickup element 2-12 has a structure in which a grounding end 12-23 and a grounding end support portion 10-23 are vibrated as vibration fulcrums and controls a vibration direction, transmits the vibration to a vibration blade 12-24, further transmits the vibration to a first opening portion on the vibration blade side of a sound conduit 41 through an elastic member 13 as sound pressure, and transmits the sound pressure to a microphone 14 connected to a second opening portion provided on the opposite side of the sound conduit 41.SELECTED DRAWING: Figure 4

Description

The present invention relates to a pickup cartridge, for example, a pickup cartridge that reads an audio signal from an analog record.

In the reproduction of an analog record, the voice vibration engraved on the analog record placed on the turntable is picked up by using a pickup cartridge. This pickup cartridge is attached to the tone arm, and the voice vibration picked up by the pickup cartridge is transmitted via the cantilever. Then, the voice vibration is converted into an electric signal by the power generation element attached to the cantilever, and the voice is reproduced by the audio device.

Pickup cartridges are roughly classified into amplitude-proportional type and speed-proportional type. The speed-proportional pickup cartridge mainly transmits vibration to the coil and converts the speed displacement of the coil into an electric signal. This method requires the coil to be housed in the gap of the magnetic circuit, and there are restrictions on the shape. Amplitude proportional pickup cartridges mainly include crystal cartridges that detect vibration using Rochelle salt. This is suitable for mass production, but its frequency characteristics are insufficient. As an amplitude-proportional type, there is also a condenser type pickup cartridge that measures the position and displacement of the electrodes, which has high sound quality, but the method of increasing the sensitivity and improving the SN ratio is to narrow the distance between the electrodes. Although it is necessary to widen the polar area, there is a limit to the above method because it affects physical vibration.

For the above reasons, as a method not found in Patent Document 1, the vibration picked up by the stylus is transmitted to the sound conduit via an elastic body and picked up as sound pressure using a microphone. So to speak, a sound pressure conversion type pickup cartridge cartridge was devised. Since this method uses a condenser microphone, it has many things in common with the above-mentioned condenser type pickup cartridge. The difference is that the sound conduit can be used to set the sensitivity regardless of the distance between the poles for detection and the pole area.

By the way, before the invention of the electric pickup cartridge as described above, there was a gramophone. The gramophone has a mechanism to transmit the vibration picked up by the needle to the diaphragm of the sound box and convert it into sound pressure. The combination of this gramophone and a microphone is the origin of the idea of the sound pressure conversion type pickup cartridge.

Initially, the sound pressure conversion type pickup cartridge was merely a combination of a gramophone and a microphone, but in Patent Document 1, the frequency characteristics and sensitivity are improved by airtightly connecting to the microphone using a sound conduit, and the sound conduit is used. Is arranged in multiple dimensions to enable stereo pickup.

The present invention further improves the sound pressure conversion type pickup cartridge of Patent Document 1, and has a structure for picking up multidimensional vibration with a sound conduit arranged in a single dimension, enabling high performance and further picking up. It is possible to increase the variation of and improve the productivity.

JP-A-2019-125407

Aie Publishing Co., Ltd. Monthly Radio Technology February 2020 Issue No. 955 P110-114

In the form of Patent Document 1, it is composed of a cartridge base member attached to the tone arm and a pickup element attached to the analog record side with the cartridge base member attached.

The pickup element sends the vibration as pressure to the sound conduit installed at an angle of 45 degrees upward from the vertical direction, and picks up this pressure vibration with the microphone provided at the outlet of the sound conduit. The pickup element must be placed at the intersection of the center lines in the extending direction, resulting in high manufacturing cost and difficulty in manufacturing. (See Patent Document 1 (paragraph number 0024, FIG. 1, FIG. 3)).

In view of the above reasons, the present invention reconsiders the shape of the pickup element, the arrangement of the sound conduit, and the support method of the pickup element, and aims to improve the performance, increase the variation of the pickup, and improve the productivity. Is.

One aspect of the pickup cartridge of the present invention is provided on a cartridge base member attached to the tone arm and a surface facing the analog record with the cartridge base member attached to the tone arm, and vibration is generated from the analog record. Of the sound conduit and the sound conduit provided in the cartridge base member, the pickup element having a pick-up element and the pickup element has a vibration vane for transmitting the picked up vibration, and the vibration vane has a vibration vane for transmitting the vibration. An elastic member that closes the first opening provided on the side where the pickup element is provided, supports the pickup element, and transmits the vibration of the vibration blade to the sound conduit, and the pickup element of the sound conduit. It has a microphone provided so as to close the second opening provided opposite to the side on which the is provided.

In the present invention, the grounding end support portion and the sound conduit opening are installed in a single dimension, and the manufacturing process is expected to be simplified. Furthermore, the inspection work is performed in the state before incorporating the cantilever and the stylus, so that the work loss is reduced. It can be suppressed. In addition, since multidimensional vibration can be detected from a plurality of sound conduit openings arranged in a single dimension, the variation of the pickup increases. Furthermore, structural restrictions are reduced and sound quality is expected to improve.

It is a side view explaining the appearance of the pickup cartridge 1 of Embodiment 1 and the pickup cartridge 2 of Embodiment 2 which concerns on this invention. It is an enlarged side view for demonstrating the structure of the pickup element 1-12 of Embodiment 1 which concerns on this invention. It is an enlarged side view for demonstrating the structure of the pickup element 2-12 of Embodiment 2 which concerns on this invention. It is an exploded view for demonstrating the structure of the pickup element 2-12 of Embodiment 2 which concerns on this invention. It is a figure explaining the arrangement of the sound conduit 41 of the pickup element 1-12 of Embodiment 1 and the pickup element 2-12 of Embodiment 2 and the phase of a signal output by a vibration direction which concerns on this invention. It is a figure explaining the structure of the grounding end and the grounding end support part of the said pickup element 12. It is a figure explaining the post-stage circuit of the pickup cartridge 1 of Embodiment 1 which concerns on this invention. It is a figure explaining the post-stage circuit of the pickup cartridge 2 of Embodiment 2 which concerns on this invention. It is a figure explaining the terminal assignment of the pickup cartridge 1 of Embodiment 1 and the pickup cartridge 2 of Embodiment 2 which concerns on this invention. It is a figure explaining the vibrating blade 12-24 of the pickup element 1-12 of the pickup element 1-12 which concerns on this invention, the enclosure 10-2a for vibrating blade, and the jig 10-2b for assembling.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description and drawings have been omitted or simplified as appropriate for the sake of clarity. In each drawing, the same elements are designated by the same reference numerals, and duplicate explanations are omitted as necessary.

As the embodiment for carrying out the invention, the pickup cartridge 1 of the first embodiment using two microphones 14 and the pickup cartridge 2 of the second embodiment using four microphones 14 will be mainly described as a vibration detection method.

First, FIG. 1 shows a diagram illustrating the appearance of the pickup cartridge 1 of the first embodiment and the pickup cartridge 2 of the second embodiment. The pickup cartridge 1 of the first embodiment and the pickup cartridge 2 of the second embodiment have cartridge base members 10-1 and 10-2, a terminal support member 11, a pickup element 12, an elastic member 13, a microphone 14, a wiring 15, and a cartridge terminal. 16. The cartridge base member 10-1, which consists of fixing pins 10-4, is attached to a tone arm (not shown) provided on a turntable for rotating an analog record. With the cartridge base member 10-1 attached to the tone arm, the pickup element 12 provided on the surface facing the analog record picks up vibration from the sound groove of the analog record, guides the vibration to the elastic member 13, and makes sound. It is converted into pressure and sent to the microphone 14. The output signal from the microphone 14 is sent to the cartridge terminal 16. In FIG. 1, since the pickup cartridge is viewed from the right side, one microphone 14 and two wirings 15 and two cartridge terminals 16 are shown. However, since the pickup cartridge 1 has the same one on the left side, it is actually used. The microphone 14 is provided with two microphones, and the wiring 15 and the cartridge terminal 16 are provided with four. Further, the pickup cartridge 2 is provided with four microphones 14 and six cartridge terminals 16. The pickup cartridge 2 is described in detail in FIGS. 3 and 4. The wiring 15 will be described later, but since it differs depending on the microphone 14 to be selected, the number of wires is described as an example. The difference between the pickup cartridge 1 of the first embodiment and the pickup cartridge 2 of the second embodiment is mainly the pickup element 12, and since there is no difference in appearance and the description is duplicated, the first embodiment and the second embodiment are described. The external view is common to FIG.

It is seen from the right side surface direction of the pickup element 1-12 which concerns on Embodiment 1 shown in FIG. The pickup element 1-12 is composed of a stylus 21, a cantilever 22, a vibration blade 24, and a grounding end 23. The stylus 21 is grounded in the sound groove of an analog record, picks up voice vibration, and the vibration is guided by the cantilever 22, and the pickup element The grounding end 12-23 of the 12 is grounded with the grounding end support portion 10-23 of the cartridge base member 10-2 and vibrates as a fulcrum, so that sound pressure can be sent to the sound conduit opening 41. Further, the vibrating blades 12-24 have a shape of being wrapped in the elastic member 13, and the connected pickup element 12 is held. Since FIG. 2 is also a view seen from the right side as in FIG. 1, only one side is shown, and in reality, the sound conduit 41 and the microphone 14 are provided.

It is seen from the right side surface direction of the pickup element 2-12 which concerns on Embodiment 2 shown in FIG. Similar to FIG. 2, the pickup element 2-12 according to the second embodiment includes a stylus 21, a cantilever 22, a vibration blade 24, and a grounding end 23, and operates in the same manner as the pickup element 1-12 according to the first embodiment. Similarly, since FIG. 3 is a view viewed from the right side, only one side is shown, and in reality, the sound conduit 41 and four microphones 14 are provided.

FIG. 4 is an oblique exploded view for explaining the positional relationship between the vibration blade 24, the elastic body 13, the sound conduit 41, and the microphone 14 of the pickup element 2-12 according to the second embodiment shown in FIG. 4 in an easy-to-understand manner. The pickup element 2-12 according to the second embodiment is provided with a sound conduit 41 and a microphone 14 for each of four sets. In the pickup element 1-12 according to the first embodiment, two sound conduits 41 and two microphones 14 are provided. As for the pickup element 1-12 according to the first embodiment, the description of the exploded view is omitted because there are many overlapping explanations. The arrangement of each sound conduit 41 is also shown in FIG.

The sound conduit 41 according to the embodiment will be described. The sound conduit 41 is a through hole, and the elastic member 13 receives the vibration of the vibration blade 24, and the elastic member 13 airtightly connected to the sound conduit 41 converts the vibration into pressure, and the vibration blade of the sound conduit 41. It feeds into the first opening on the side. A microphone 14 is provided in the second opening on the opposite side of the sound conduit 41, and can be picked up as sound pressure. The arrangement of the sound conduit 41 is as shown in FIG. 5, and two or four sound conduits 41 are provided on the surface of the grounding end support portion 10-23 in the direction of 45 degrees from the grounding end support portion 10-23. Be done. The arrangement of the sound conduit 41 shown in FIG. 5 is an example, and depending on the size of the microphone 14 used, the housing of the microphone 14 may interfere, and in that case, the arrangement can be changed each time. The two or four sound conduits 41 are airtightly connected, but the plurality of sound conduits 41 are individually sealed and do not share pressure with each other. The diameter of the sound conduit 41 is set by the diameter of the diaphragm of the microphone 14 and the sensitivity of the microphone 14. The sound conduit 41 is, for example, a cylindrical hole, but a space provided with a mechanism for airtightly connecting the vibration blade 24 and the microphone 14 and transmitting pressure is considered to be the sound conduit 41. The microphone 14 is hermetically fixed to the second opening of the sound conduit 41 with a high-hardness adhesive. It seems that some microphones have a shape in which the port (sound collecting hole) of the microphone 14 plays the role of a sound conduit 41. In this case, the same applies even if the port of the microphone 14 is directly blocked by the elastic member 13. In any case, if the structure is such that the diaphragm of the microphone 14 and the elastic member 13 do not come into direct contact with each other, it is considered that the space between the microphone 14 and the elastic member 13 plays the role of the sound conduit 41. That is, it is considered that the elastic member 13 and the microphone 14 are fluidly coupled. The fluid may be another gas instead of air, and it is also possible to improve the performance by using a gas other than air. Although it is theoretically possible to use a liquid, it is not realistic at present due to the specifications of the microphone 14. If the sound conduit 41 is not sealed or coupled and is picked up in an open space, frequency characteristics and sensitivity cannot be expected. The setting of the sound conduit 41 will be described in detail later.

The vibration blade 24 according to the embodiment will be described. The vibrating blade 24 has a role of determining the direction of vibration transmitted from the cantilever 22. The vibrating blade 24 vibrates with the ground contact end 23 as a vibration fulcrum, and sends pressure to the sound conduit 41 via the elastic member 13. The shape is like a cantilever with wings or petals, and the central part has a cylindrical overhang in the direction of the cantilever to firmly fix it to the cantilever, and the grounding end in the direction opposite to the cantilever. There is a dent. The pickup element 1-12 according to the embodiment has two blades, and the pickup element 2-12 according to the embodiment has four blades. The length, area, and shape of the blades differ depending on the microphone 14, and various possibilities can be considered. For example, it can be shaped like a sword guard by connecting four blades. That is, the shape is a part having a rising surface from the cylindrical cylinder of the cantilever 22, and the one that can change the direction of vibration and apply pressure to the sound conduit 41 can be defined as a vibration blade. The vibrating blade 24 has a structure that is wrapped in an elastic member 13, and also has a role of supporting the cantilever 22 and the stylus 21 that are adhesively fixed to the tip of the vibrating blade 24.

The microphone 14 according to the embodiment will be described. MEMS (Micro Electro Mechanical Systems): Among devices that integrate machine element parts at high density by semiconductor process technology, microphones made using the above-mentioned technology are called MEMS microphones, and the size is very 3 mm x 2 mm. small. Further, the MEMS microphone is a condenser microphone, and generally detects the position difference between the fixed electrode having an electret layer and the diaphragm. The microphone 14 described herein refers to this MEMS microphone. In the embodiment of the present invention, the MEMS microphone operates at a sound pressure of around SPL130 dB. Although it is a small diaphragm, the sensitivity can be set high, and a higher output than the conventional condenser type pickup cartridge can be produced by the MEMS microphone. (SPL = sound pressure level)

The elastic member 13 according to the embodiment will be described. The elastic member 13 has a role of sealing the opening of the sound conduit 41, converting vibration into pressure and transmitting it, and a role of wrapping the vibration blade 24 and supporting the entire pickup element 12, and also damping a certain amount of vibration to be unique. It also has the effect of suppressing vibration. A paste-like or liquid silicone rubber is poured into the enclosure 10-2a for a vibrating blade, which is an enclosure, the first opening of the sound conduit 41 is sealed, and the vibrating blade 24 is fixed. Further, the enclosure 10-2a for vibration blades is provided with an opening for inserting a jig in order to improve the accuracy of the manufacturing process. Therefore, it is difficult to express the shape, but in FIG. 4, a hatch is hung at the place where the silicone rubber is poured. The material is not limited to silicon rubber as long as the elastic member 13 has appropriate elasticity, wraps and holds the vibrating blade, seals the sound conduit 41, and can transmit pressure. The vibrating blade enclosure 10-2a will be described in detail in paragraph No. 0041, in the manufacturing process.

As described in the problem to be solved by the invention, in the form of Patent Document 1, the cantilever of the pickup element must be arranged at the intersection of the center lines in the extending direction from the openings of the left and right sound conduits 41. Mass production involves a difficult assembly process and causes product loss.

As shown in FIGS. 2 to 4, in the pickup cartridge 1 of the first embodiment and the pickup cartridge 2 of the second embodiment, the grounded end support portion 10-23 and the sound conduit are grounded at the grounded end 12-23 of the pickup element 12. By arranging the opening 41 on a flat surface, the assembly process can be simplified, the work accuracy can be improved, and the inspection work can be made more efficient.

The pickup cartridge 1 of the first embodiment and the pickup cartridge 2 of the second embodiment are divided into a cartridge base member 10-1 and a 10-2, in order to facilitate the arrangement of parts in the production process. The cartridge base members 10-1 and 10-2 are fixed by fixing pins 10-4. The cartridge base member 10-2 is provided with a grounding end support portion 10-23 that is grounded and stabilized with the grounding end 12-23 of the pickup element 12.

Next, the grounding end support portion 10-23 shown in FIG. 6, which shows the grounding end 12-23 and the grounding end support portion 10-23 according to the embodiment, is a spike-shaped protrusion, a ball bearing, or an elastic member. Receive at 13 (elastic body grounding). In addition, not limited to the form given here, if the grounding end 12-23 and the grounding end support portion 10-23 are in contact with each other and have a mechanism for controlling vibration as a fulcrum, the grounding end 12-23 and the grounding end support portion 10-23 and the grounding end support portion 10-23 are in contact with each other. It can be seen as the grounding end support portion 10-23. The ground contact end 12-23 according to the embodiment is a common part with the vibration blade 24, and is wrapped in the elastic member 13. As shown in paragraph No. 0025, the elastic member 13 is poured with a silicone rubber-based adhesive and cured. The pickup element 12 is held by wrapping the vibrating blades 12-24. In the pickup element 1-12 according to the first embodiment, the noise component and the signal component cannot be separated from each other. Therefore, the method of receiving the pickup element 12 only by the elastic member 13 causes a problem due to a large amount of noise. This is the shape selected by the pickup element 2-12 according to the second embodiment.

The extraction of the signal of the pickup element 1-12 according to the first embodiment will be described. The pickup element 1-12 according to the first embodiment moves with the grounding end support portion 10-23 as a fulcrum, and controls the phase and direction of vibration. Two microphones 14-a and 14 are in the second opening on the side opposite to the pickup element 1-12 side of the two sound conduits 41-a and 41-b of the pickup element 1-12 according to the first embodiment. -B is used, and as shown in the circuit diagram of FIG. 7, a stereo output can be taken out by Rch non-inverting Lch inversion, and a monaural output can be taken out by Rch + Lch differential output. When using a MEMS microphone equipped with a balanced output, the Lch can take out the-output and the Rch can take out the + output, so the interface is non-inverting amplification on both the left and right sides. Further, the output taken out from the neutral point of 14-a and 14-b becomes a longitudinal vibration component. Since the signal level of the vertical vibration output is -6 dB of the horizontal vibration, it is necessary to adjust it with an amplifier.

The microphone mounting board arranged behind the microphone 14 is not always necessary for carrying out the invention, and although the description in the drawings is omitted, it is mounted on the board from the viewpoint of improving productivity. It is more reliable to assemble the microphone 14 with. The MEMS microphone has a bottom port and a top port, and since the bottom port has a sound collecting hole on the mounting surface, the orientation of the base to be mounted is on the sound conduit 41 side, but the second opening of the sound conduit 41 The orientation of the substrate is not particularly important in the present invention as long as the shape is ensured.

In FIG. 4, the direction of the vibration mode of the cantilever 12-22 according to the embodiment of the present invention is also shown. The definitions of the two-dimensional vibration and the three-dimensional vibration described in the embodiment of the present invention will be described. The four vibration modes of stereo ST-Rch and ST-Lch, longitudinal vibration, and lateral vibration are referred to as two-dimensional vibration, and those to which Z-axis vibration is added are referred to as three-dimensional vibration.

The signal extraction of the pickup element 2-12 according to the second embodiment will be described. In the pickup element 2-12 according to the second embodiment, four microphones 14 are used for the four sound conduits 41, and 14-a and 14-d are used as 14-c and 14-b as shown in FIG. Stereo playback is performed by outputting each differentially.

In the form of grounding the elastic body of the pickup element 2-12 according to the second embodiment, the vibration in the Lch, that is, the X-axis direction and the vibration in the Rch, that is, the Y-axis direction are picked up, and the vibration in the Z-axis direction is picked up. Since vibration in the Z-axis direction is not required for analog record playback (music playback), the grounding end support portion 10-23 is received by a spike or ball bearing to suppress vibration in the Z-axis direction, and vibration is applied to the X-axis and Y-axis. Although it is necessary to narrow down, in the form of the pickup cartridge 2 of the second embodiment using the sound conduit 41 and four microphones 14, the common mode is used by using two diagonal microphones 14 to form two differential output circuits. In the pickup cartridge 2 of the second embodiment, there is no problem even in the form of grounding the elastic body.

In the pickup cartridge 2 according to the second embodiment, as shown in the circuit diagram of FIG. 8, the X-axis and the Y-axis have a diagonal microphone as a differential output, and the Z-axis is a neutral point of the differential output of the X-axis and the Y-axis. By amplifying the signal extracted from the above, a three-axis signal can be obtained. Since the output level of Z-axis vibration is also -6 dB on the X-axis and Y-axis, it is necessary to adjust it with an amplifier.

Of the outputs of the three axes, the vibration in the Z-axis direction is not necessary for music reproduction and is rather harmful. Specifically, it includes eccentricity of analog records, mechanical noise, wow and flutter, howling components, and the like. By outputting only the noise component as an application in the Z-axis direction, it can be effectively used for canceling the noise component in the subsequent circuit.

Next, the channel phase will be shown.

FIG. 5 shows the phase characteristics of the channels. In the pickup element 1-12 according to the first embodiment, the vibration of the right wall surface of the sound groove of the analog record is input to the right sound conduit 41-b, and the vibration of the left wall surface is input to the left sound conduit 41-a. To. In the form of Patent Document 1, the sound conduit 41 is arranged at an angle of 45 degrees upward with respect to the analog record board. In this case, Lch is in the normal phase and Rch is in the reverse phase, but in the pickup cartridge 1 of the first embodiment, the vibrating blades 12-24 protrude at an angle of 45 degrees downward facing the analog record board, and there. The first opening of the sound conduit 41 is arranged at an angle of 90 degrees from. That is, the phase is opposite to the form in Patent Document 1, that is, Lch is the opposite phase and Rch is the normal phase. (See Patent Document 1 (Fig. 7))

FIG. 5 also shows the phase characteristics of the pickup element 2-12 according to the second embodiment using the four microphones. The vibration of the right wall surface is input to the right sound conduit 41-b, and the opposite phase is input to the diagonal sound conduit 41-c. Further, the vibration of the left wall surface is input to the left sound conduit 41-a, and the opposite phase thereof is input to the diagonal sound conduit 41-d.

Next, the assembly and production process will be shown.

First, the vibration blade enclosure 10-2a according to the embodiment will be described. The vibration blade enclosure 10-2a is a portion of the cartridge base member 10-2 that protrudes from the surface of the cartridge base member 10-2 facing the pickup element 12 so as to surround the vibration blade 24 and the first opening of the sound conduit 41. The pickup element 12 The side surface is open and has a shape to which the vibrating blades 12-24 can be assembled. Further, the vibration blade enclosure 10-2a is provided with an opening for inserting the positioning jig 10-2b, 10-2c, in order to accurately assemble the vibration blades 12-24. The assembly process of the pickup element 1-12 according to the first embodiment is shown in FIG. 10. The 10-2d, which is the insertion portion of the positioning jig 10-2b, is inserted into the opening 10-2c of the vibration blade enclosure 10-2a. After that, a silicone rubber-based adhesive is applied, and the vibrating blades 12-24 including the grounding end 12-23 are incorporated. The grounding end support portion 10-23 also serves as a positioning guide, and accurate positioning is possible by the positioning jig 10-2b. After removing the positioning jig 10-2b, the hole is re-bonded to silicon. Fill with agent. At this time, measurements such as left and right level checks are possible in an unassembled state. In the case of mass production, the characteristics will be stable if silicone rubber is poured into the enclosure for vibration blades 10-2a and then degassed in a decompression chamber. The enclosure for vibrating blades prevents the cured silicone rubber from being unintentionally deformed, and also serves as a frame for filling a paste-like or liquid silicone rubber during assembly. There are two insertion portions for the positioning jig, and the process is one. In the second embodiment, there are two more sound conduits 41, another positioning jig 10-2b is required, and the number of steps is 2. In addition, since it will be duplicated, the description will be omitted.

The process can be assembled by assembly line. After that, it is attached to the cartridge base member 10-1 to perform wiring work, and the stylus 21 and the cantilever 22 are attached to complete the process.

The cartridge base member 10-1 may be any material such as metal, resin, wood, stone, and coral, and it is possible to stick to the material as long as it is a hobby product. In addition, the terminal support member 11 uses an insulating material. The stylus 21 of the pickup element 12 is diamond, and the cantilever 22 can be manufactured of gemstones such as sapphire and ruby, or boron, zirconia, aluminum pipe, and the like.

Next, frequency characteristics and signal processing will be shown.

Regarding signal processing of frequency characteristics, Patent Document 1 describes that it was found in an experiment that equalizing is not necessary, but it was confirmed that some irritating is required to accurately flatten the frequency characteristics. Was done. This took time because the characteristics of the microphone, the RIAA characteristics of the analog record, and the acoustic characteristics of the sound conduit 41 were closely intertwined and difficult to identify. (See Patent Document 1 (paragraph number 0049))

Regarding the frequency characteristics of the pickup cartridge 1 of the first embodiment and the pickup cartridge 2 of the second embodiment according to the present invention, the characteristic element of the microphone 14 is large, which is greatly influenced by the selection of the microphone 14, but also the microphone 14 It can also be solved by selecting. Regarding the acoustic characteristics of the sound conduit 41, the sound conduit 41 has a characteristic of pushing down the frequency peak of the microphone 14 as compared with the open space because it is a closed space, but the sound conduit 41 itself is a space of about 1 mm and is a sound wave in the audible band. Shorter than long. For the above reasons, the acoustic peak of the sound conduit 41 itself is considered to be in the high frequency range of 100 kHz or more, and the analog record reproduction can be ignored. That is, it can be flattened by the equalizing circuit of the pickup cartridge having the conventional amplitude proportional characteristic. Moreover, since it has higher sensitivity than the conventional condenser type pickup cartridge, it is possible to equalize with the minimum deterioration of sound quality. (Refer to Non-Patent Document 1 (p.113-114) for amplitude proportional characteristics).

The RIAA characteristic refers to the characteristic of the equalizing curve (RIAA curve) applied when cutting a record. Normally, when cutting an analog record, the speed is proportional because an electromagnetic coil is used. Therefore, if it is left as it is, the amplitude width of the low frequency band becomes too large and interferes with the adjacent sound groove. As a means to solve this, a general analog record is cut by applying equalizing to lower the low range and raise the high range. As mentioned above, since the RIAA characteristics are known techniques, detailed description thereof will be omitted.

The amplitude proportional characteristic refers to a characteristic obtained when an analog record of RIAA characteristic is reproduced by an amplitude proportional pickup cartridge. When playing an analog record with RIAA characteristics, if it is a speed-proportional pickup cartridge, it will be restored by performing the equalizing opposite to that at the time of cutting. In the case of an amplitude-proportional pickup cartridge, a different equalizing is required. The width is smaller than the speed-proportional equalizing, and the amplitude-proportional type is more advantageous in terms of sound quality. Since the amplitude proportional type is a known technique, detailed description thereof will be omitted.

All the circuit diagrams in the present specification are principle circuits, and only the phase processing is described, and the power supply circuit and the equalizing circuit are omitted. Equalizing is a general circuit as described above, and the microphone power supply is set by the selected microphone.

Description of selection of microphone 14 and setting of sound conduit 41

Regarding the selection of the microphone 14 and the setting of the sound conduit 41, when the MEMS microphone is used in this embodiment, the maximum SPL of the microphone becomes a problem. A microphone having a small maximum allowable load SPL is distorted from around SPL110 dB, but the maximum output SPL of the pickup cartridge according to the embodiment is 150 dB, so that the microphone is distorted as it is. Therefore, the area of the first opening of the sound conduit 41 is made smaller than that of the microphone diaphragm, and the SPL is adjusted. This mechanism reduces the SPL, but it does not waste energy, but converts the force into an effective value, like a transmission in an automobile. As the amplitude is reduced, the energy oscillates with a margin, so that the frequency characteristics are improved. (See Patent Document 1 (paragraph number 0029-0031, FIG. 4)) (see Non-Patent Document 1 (p.111-112)).

It is advisable to select a microphone 14 that can be used by applying a sound pressure of about SPL130 dB. There are some MEMS microphones with a built-in amplifier and some without a built-in amplifier, but the microphone without a built-in amplifier does not distort even if a higher sound pressure is applied by receiving the interface circuit with high resistance. Was confirmed in the experiment. In order to achieve high sensitivity with the conventional condenser type pickup cartridge described in the background technology, there are two options, either to reduce the distance between the poles or to increase the pole area, and if they go too far, they will cause physical vibration. It is thought to have an impact. In the pickup cartridge according to the embodiment, when SPL130 dB is applied to a microphone having a general sensitivity of −42 dB / SPL94 dB, the output voltage is around −6 dB, and it can be sent to the line amplifier with almost unity gain. High sensitivity is a great advantage because it also improves the signal-to-noise ratio. It is assumed that the interface circuit is individually set according to the selected microphone, and the circuit shown in the present specification is an example.

Description of output terminal

FIG. 9 shows the output terminal 16 of the pickup cartridge 1 according to the first embodiment. Normally, the record player has four wirings in the tone arm, but the pickup cartridge 1 according to the first embodiment requires two signal lines, and the remaining two are excluding the signal lines. That is, the microphone 14 power line and the microphone 14 GND line must be common to Lch and Rch. This is the same as the preceding Patent Document 1. (See Patent Document 1 (paragraph number 0042, FIG. 6))

Regarding the output terminal 16 of the pickup cartridge 1 according to the first embodiment, in the embodiment of Patent Document 1, the negative electrode terminal of Lch is applied to the GND and the negative electrode terminal of Rch is applied to the power supply terminal of the microphone 14. In the pickup cartridge 1 pertaining to 1, the negative electrode terminal of Lch is the microphone 14 power supply, and the negative electrode terminal of Rch is applied to the microphone 14 GND. Since the negative electrode terminal is green, it is assigned to the terminal opposite to that of Patent Document 1 in order to eliminate intuitive miswiring. (See Patent Document 1 (paragraph number 0042, FIG. 6))

Regarding the pickup cartridge 2 according to the second embodiment, the number of lines used can be reduced by superimposing a power source, but when a general-purpose circuit is used, at least six lines are required, and a dedicated tone arm or a dedicated tone arm or , Can only be used for dedicated record players. Especially when archiving old analog records into digital data, it has excellent noise characteristics, and high-quality sound can be obtained by preparing a dedicated machine in advance. Further, since the studio equipment has many balanced inputs, the pickup cartridge 2 according to the second embodiment can be considered for such an application.

When used in a studio device, it is effective to generate a power source using an interface using a microphone amplifier and a phantom power source of the microphone amplifier in the form of Patent Document 1. In the case of using the balanced output MEMS microphone of the pickup cartridge 2 according to the second embodiment or the pickup cartridge 1 according to the first embodiment, balanced transmission is possible. (See Patent Document 1 (paragraph number 0036, FIG. 7))

The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit.

1 Pickup cartridge 1
2 Pickup cartridge 2
10-1 Cartridge base member 10-2 Assembling member of cartridge base member 10-2a Enclosure for vibration blade for mounting pickup element 12 of cartridge base member 10-2 10 Jig for positioning vibration blade of pickup element 12 10 -2c Jig insertion opening of the enclosure for vibration blades for mounting the pickup element 12 10-2d Jig insertion part for positioning the vibration blades of the pickup element 12 10-4 Mounting pin for cartridge base member 11 Terminal support member 12 Pickup element 12-24 Vibration blade of pickup element 12-23 Grounding end of pickup element (vibration fulcrum)
10-23 Grounding end support portion (vibration fulcrum) of the pickup element 12 provided on the cartridge base member 10-2.
13 Elastic member 14-a Microphone Lch-
14-b Mike Rch +
14-c Mike Rch-
14-d microphone Lch +
15 Wiring 16 Cartridge terminal 21 Stylus 22 Cantilever 41-a Sound conduit Lch-
41-b Sound conduit Rch +
41-c Sound conduit Rch-
41-d sound conduit Lch +
T1 Left channel positive terminal T2 Right channel positive terminal T3 Microphone power terminal T4 Microphone GND terminal T5 Left channel negative terminal T6 Right channel negative terminal

Claims (6)

The cartridge base member attached to the tone arm and a pickup element provided on the surface of the cartridge base member facing the analog record in a state of being attached to the tone arm and picking up vibration from the analog record. The pickup element has a vibration blade that transmits the picked up vibration, and is provided on the side of the sound conduit and the sound conduit provided on the cartridge base member to which the vibration blade transmits the vibration, on which the pickup element is provided. An elastic member that closes the first opening and supports the pickup element and transmits the vibration of the vibration blade to the sound conduit is provided opposite to the side of the sound conduit where the pickup element is provided. A pickup cartridge having a microphone provided so as to close the second opening. The cartridge base member has a grounding end provided at an end of the pickup element on the side opposite to the stylus on the side in contact with the analog record, and the grounding end of the pickup element is the cartridge base member. The pickup cartridge according to claim 1, wherein the pickup element is supported by the grounding end support portion and vibrates with the grounding end in contact with the grounding end support portion as a center point. The cartridge base member is an enclosure for vibration blades provided so as to surround the first opening of the sound conduit provided on the side where the vibration blades of the cartridge base member are provided and the vibration blades of the pickup element. The pickup cartridge according to claim 1 or 2, wherein the enclosure for vibration blades has an opening for inserting a jig for positioning. The pickup cartridge according to any one of claims 1 and 3, wherein the microphone is a MEMS microphone. Two sound conduits are provided on the surface of the cartridge base member facing the pickup element, two microphones are provided in the second openings of the two sound conduits, and the outputs of the two microphones are provided. Detect the potential and pick up the vibration, or detect the potential difference between the outputs of the two microphones and pick up the vibration, or detect the potential of the neutral point of the outputs of the two microphones and pick up the vibration. , The pickup cartridge according to any one of claims 1 and 4. Four of the sound conduits are provided on the surface of the cartridge base member facing the pickup element, four of the microphones are provided in the four second openings of the four sound conduits, and the outputs of the four microphones are provided. Detects potential and picks up vibration, or detects the potential difference between the outputs of two diagonally arranged microphones out of the four microphones and picks up vibration, or outputs of all four microphones. The pickup cartridge according to any one of claims 1 and 4, which detects the potential of the neutral point and picks up the vibration.

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