JP2000268301A - Record player - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a needle skip phenomenon and allow even a beginner without skillfulness to play satisfactory DJ performance by positioning a rotating axial core of an arm axis on a straight line perpendicular to another straight line that passes rotation axis of a turn-table in the vicinity of the midpoint in an effective width of a record groove. SOLUTION: A beginning point R, a midpoint Q and an end point of a record groove 3' are determined on a record center line B in the radial direction that passes at a rotating axis core C of a turn-table 2. In addition, a tone arm 5 is positioned so that the tangential direction of the record groove 3' and the axial line direction of an arm axis 6 coincide with each other at the midpoint Q when viewed in a plane. Suppression of a needle skip phenomenon can be realized at a remarkable rate within a slope in the range of a central effective width a3, a4 measured from a point a3 to a point a4 on the record center axis, that are obtained by dividing an effective width a1, a2 of the record groove 3' on the record center line B, passing the rotating axis core C, approximately equally into four portions in the radial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a record player used for, for example, a disc jockey (hereinafter simply abbreviated as DJ), and in particular, to directly rotate and reversely rotate a record plate by a finger operation of an operator which is a kind of DJ performance. The present invention relates to a record player adapted to a so-called scratch performance operation for outputting sound.

[0002]

2. Description of the Related Art FIG. 1 is an operation diagram showing a performance operation state of a scratch performance using a conventionally known record player. Conventionally, the record player 1 has been used as a means for reproducing information from a recorded record board. However, in recent years, as a DJ performance mode, a scratch performance has been performed in which artificially new sound information is created via the cartridge 9 by directly and artificially performing a forward / reverse rotation operation on the record plate 3 with a fingertip. ing. In this case, the sound information of the record player is mixed with sound information from other attached sound sources, and used as a means for creating a new sound source world. That is, the record player 1 is used as if it were a single musical instrument.

FIGS. 2A and 2B show a conventional HiF.
FIG. 7 is an operation explanatory diagram when the i-audio record player 1 is used as such a scratch performance. FIG. 3A shows a forward rotation operation of the record plate 3 placed on the turntable 2, and FIG. 3B shows a reverse rotation operation thereof. In these figures, each cartridge 9
The direction of the stylus pressure received by the stylus 10 is indicated by a vector. The tone arm 5 includes an arm shaft 6 and a cartridge 9.
And formed.

Since the record player 1 widely used by DJs is originally developed for HiFi audio, the record player 1 is designed to have the best sound quality when used in the normal rotation shown in FIG. ing. Therefore, the arm shaft 6 of the tone arm 5 is held rotatably in a horizontal direction by a vertical rotation axis (fulcrum) P provided on the pivot portion 8, and the arm shaft 6 is curved in an S-shape. . That is, an offset angle α (generally 21.4 °) is provided between the axial direction 6 ′ of the arm shaft 6 and the axial direction 9 ′ of the cartridge 9, and the cartridge 9 is bent inward, so that a tracking error occurs. (Tracking error) is compensated. Further, the arm shaft 6 is extended to the fulcrum P side, and the needle pressure adjuster 7 is
Is provided so that reproduction is performed in a state where optimal stylus pressure is obtained.

[0005]

However, in the case of the DJ's scratch performance, both the number of rotations and the direction of rotation of the record change arbitrarily as shown in FIGS.
At this time, the force received by the needle tip 10 of the cartridge 9 becomes a tangential force F during normal rotation as shown in FIG. 4A, and a tangential force F during reverse rotation as shown in FIG. '. The magnitude of each of the forces F and F ′ is
Component force F ₂ in the X-axis direction which is a straight line connecting
F ′ ₂ and component forces F ₁ and F ′ ₁ in the Y-axis direction perpendicular thereto.

At the time of forward rotation, as shown in FIG. 2A, a needle pressure F1 in the inner diameter direction of the record plate 3 is constantly applied to the needle point 10 during tracking. The needle pressure F _'1 of the outer diameter side direction during reverse rotation are opposite at all is applied. Therefore, when the record sheet 3 positive and reverse rotation during scratch performance, force F ₁ and F _'1 of the inner diameter side and outer diameter side direction is applied to the repeated needlepoint 10. When the forces F ₁ and F ′ ₁ become so large as to exceed a certain frictional force and jump out of the record groove, the needle tip 10 jumps out of the groove and a so-called “needle jump phenomenon” occurs. At this time, the output sound is disturbed, which causes discomfort to the audience.

[0007] For this reason, despite the fact that the number of DJs who wish to perform is increasing in recent years, it is quite necessary to change the record plate 3 between normal rotation and reverse rotation at high speed while preventing the needle jump. It will be a performance technique that requires skill. Therefore, there is a problem that the number of performers does not increase even though there are many performers. Naturally, this has also been a cause of limiting the spread of audio accessories used with the record player 1.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and when the rotation direction of a record plate is suddenly changed between forward rotation and reverse rotation by a scratch performance operation, the needle point of a cartridge is changed. To provide a record player that prevents needle jumping by minimizing the inward and outward component forces received as much as possible, and that can be used well by inexperienced players without being limited to skilled players. It is.

[0009]

SUMMARY OF THE INVENTION According to the present invention, there is provided a record player for a disc jockey which is suitable for a scratch performance operation in which a sound is output by directly rotating a record plate in a forward or reverse direction by an operator's finger operation. , A turntable that is driven to rotate about a rotation axis C, and a turntable that is supported rotatably in a horizontal direction about a rotation axis P located outside the turntable. An arm shaft positioned on a straight line connecting P and a needle that follows the record groove of the record plate; and a cartridge that is held at the rotating end of the arm shaft and detects a sound signal by the needle that follows the record groove of the record plate. ,
And the rotation axis P of the arm axis is positioned on a straight line orthogonal to a straight line passing through the rotation axis C of the turntable near the middle of the effective width a ₁ a ₂ of the record groove. Achieved by record players.

According to the present invention, in order to suppress the needle jump when the record plate is rotated forward and backward by a finger operation, the turn is made so as to suppress the inward and outward component forces applied to the needlepoint of the cartridge as much as possible. This defines the positional relationship between the record groove on the table and the fulcrum P of the arm axis. Therefore, in principle, the most preferred embodiment is that the start point R and the end point S of the record groove on the straight line B extending radially from the rotation axis C of the turntable, and the rotation center (rotation axis) of the tone arm, that is, What is necessary is just to make an isosceles triangle with the fulcrum P and the fulcrum P as vertices. If the straight line PQ connecting the intersection Q and the fulcrum P is located on a straight line passing through the intersection Q and orthogonal to the straight line B or on a parallel line close to this straight line, the fulcrum P
May be arranged adjacent to or separated from the turntable.

With the sliding sheet interposed between the record plate and the turntable, the turntable can be rotated in the forward direction at a constant rotational speed, and the record plate can be reversed with the fingertip. At this time, the record plate is slid on the slide sheet, or the record plate and the slide sheet are slid on the turntable. Note that both the record board and the turntable may be reversed with a fingertip.

The rotation axis P of the arm axis is orthogonal to a straight line B passing through the rotation axis C of the turntable, and divides the effective width a ₁ a ₂ of the record groove together with the intermediate point Q in the radial direction into approximately four equal parts. If they are located on a straight line passing between the points a ₃ and a ₄ , a sufficient effect can be obtained.

The rotation axis P of the arm shaft may be determined as follows. In other words, the first radius having the radius R ₀ as the radius from the rotation axis C of the turntable to the intermediate point Q of the effective width a ₁ a ₂ .
A straight line B passing through an intersection Q of the virtual circle W and a second virtual circle D having a diameter _equal to the distance D0 between the rotation axes C and P of the turntable and the arm axis and passing through the rotation axis C of the turntable. This rotation axis P is determined on a straight line orthogonal to

It is most preferable that the starting point R and the ending point S of the record groove on the straight line B and the rotation axis P be the rotation axis P.
Is to be an isosceles triangle with the vertex as the vertex. It is preferable that the rotation axis P is as far away from the intersection Q as possible. That is, the arm shaft is made sufficiently long. By doing so, the tracking error at the start point R and the end point S of the record groove can be reduced. It is convenient to adjust the needle pressure if the arm shaft extends toward the rotation axis P and a needle pressure adjusting device is provided in this extended portion.

If the horizontal rotation axis Pv that enables the arm shaft to rotate in the vertical direction is set at a position higher than the upper surface of the record plate, the needle pressure at the time of reverse rotation of the record plate becomes positive as described later. Can be increased from the time of rotation,
The effect of preventing needle jump at the time of reverse rotation is increased. The needle pressure at the time of the reverse rotation increases as the distance from the needle tip to the rotation axis Pv decreases, in other words, as the length of the arm axis decreases. On the other hand, it is desirable that the rotation axis P that enables the horizontal rotation described above is as far as possible from the turntable. Therefore, in order to satisfy these requirements, the horizontal rotation axis Pv that enables the vertical rotation can be displaced toward the cartridge side from the vertical rotation axis P that enables the horizontal rotation. I just need.

The needle pressure adjusting device may be a weight whose center of gravity is located below the vertical axis Pv of rotation. In this case, the needle point and the weight (center of gravity) located on both sides of the rotation axis Pv are both located below the rotation axis Pv, so that the balance can be obtained in a balance-like shape. . Therefore, the side force applied to the needle tip acts to vibrate the weight in the left-right direction (the direction perpendicular to the arm axis), but this vibration can be suppressed by the weight of the weight. As a result, the side force generated at the tip of the needle at the time of forward / reverse change is suppressed, and the effect of preventing jumping of the needle is further increased.

[0017]

FIG. 3 is an explanatory view showing the arrangement and operation of the turntable 2 and tone arm 5 of the record player 1 according to the present invention. 3A shows a state in which the tone arm 5 is at the starting point R of the record groove 3 ', FIG. 3B shows a state in which the tone arm 5 is at the substantial middle point Q of the record groove, and FIG. The state at the end point S of the groove is shown. In these figures, the force acting on the needle tip 10 when the turntable 2 rotates forward (indicated by a solid arrow) is indicated by a solid line, and the force acting on the needle tip 10 when the turntable 2 is rotated in a reverse direction (indicated by a dotted arrow) is indicated by a broken line. Is displayed in vector.

In the record player 1 of this embodiment, the functions of the turntable 2, the tone arm 5, the stylus pressure adjuster 7, the cartridge 9, the needle point 10 and the like are almost the same as those of the HiFi audio player. However, there are characteristic differences in the structure.

Compared to HiFi audio,
The first difference of the record player 1 of the present invention lies in the structure of the tone arm 5 and the relative positional relationship between the tone arm 5 and the turntable 2, as is apparent from FIGS. The second difference is that a sliding sheet or a sliding mat 2 ′ having a small coefficient of friction is arranged between the turntable 2 and the record plate 3. Conventionally, a fixed mat made of a rubber material having a large coefficient of friction that does not cause slippage between them is laid, whereas the record player 1 for DJs is to positively and reversely rotate the record plate 3 by finger operation. .

The present invention defines the relative positional relationship between the former structure of the tone arm 5 and the turntable 1. That is, the tone arm 5 shown in each drawing of FIG.
The arm shaft 6 is rotatably supported in a horizontal direction about a fulcrum (rotary shaft center) P provided at the center. This arm axis 6
Extends above the record groove 3 ', and a cartridge 9 is fixed to one end (rotating end) thereof. Further, the other end of the arm shaft 6 extends from the fulcrum P, and a needle pressure regulator 7 composed of a weight for adjusting the needle pressure of the needle tip 10 of the cartridge 9 is provided on this extended portion.

Here, the arm shaft 6 is straight, without being bent into an S-shape as in the prior art. Further, unlike the case of FIG. 2, the offset angle α between the axial direction 6 ′ of the arm shaft 6 and the axial direction 9 ′ of the cartridge 9 is zero in plan view. Therefore, the axial direction 9 'of the cartridge 9 coincides with the axial direction 6' of the arm shaft 6, and the tone arm 5 has a straight straight structure in plan view. Further, the arm shaft 6 is in a pipe shape and has sufficiently high rigidity. For example, aluminum pipe and brass pipe
By having a heavy structure, transmission of unnecessary vibrations is suppressed,
The howling resistance can be improved.

At the time of forward rotation of the record plate 3, FIG.
Force at the position of the start point R of the record groove 3 'to tip 10, as shown in (frictional force) f _R is applied tangentially at the R point. The tangential has an angular difference theta ₁ between the axial direction i.e. X-axis direction of the arm shaft 6. This force _{f R1,} and X-axis direction of the component force _{f R2,} this inner component force _{f R1} perpendicular direction i.e. Y-axis direction is generated. As shown in FIG. 3 (B), when the needlepoint 10 is positioned at the substantial midpoint Q of the effective width of the record groove 3 ', the force f _Q occurs. Since the fulcrum P of the arm shaft 6 is arranged on a straight line in the tangential direction of the groove 3 ', the component force in the Y-axis direction perpendicular to the arm shaft 6 is zero. Further, as shown in FIG. 3 (C), the needle tip 10 has a groove 3 '.
When positioned at the end point S of the force f _S is applied tangentially. Resulting negative angular difference theta ₂ between the X-axis direction of the arm shaft 6, the outer component force f _S1 of the Y-axis direction perpendicular to the X-axis direction of the component force f _S2 occurs.

When the record plate 3 rotates in the reverse direction, FIG.
As shown in FIGS. 3A, 3B, and 3C, the direction and magnitude of the force applied to the needle tip 10 of the cartridge 9 and the respective component forces are completely opposite to those in the above-described normal rotation. become,
The vectors are indicated by broken lines in each figure. As is clear from these figures, the component forces in the Y-axis direction perpendicular to the arm axis 6 are f _R1 and f _S1 indicated by solid lines during normal rotation, and f ′ _R1 and f indicated by broken lines during reverse rotation. ' _S1 , which appear in opposite directions. However, the magnitude of each of these component forces is reduced to half or less as compared with the case where a conventional HiFi audio tone arm (see FIG. 2) is used.

That is, in the record player 1 of the present invention, the angle difference between the tangential direction of the record groove 3 'and the axial direction of the arm shaft 6 is θ ₁ or θ ₂ which is significantly smaller than the conventional θ _0.
Can be suppressed. Particularly, around the center position Q of the substantial effective width of the record groove 3 ', this angle difference becomes substantially zero. Therefore, it is possible to almost completely prevent the inward and outward component forces acting on the tone arm 5 itself during the forward rotation and the reverse rotation from increasing. That is, each of the vector forces f _R1 , f ′ _R1 , f ′ _S1 , f ′ _S1 becomes sufficiently small. Therefore, each vector force is as shown in FIG.
The vector F ₁ and F ′ _{1 in} the inward and outward directions received by the arm shaft 6 of the conventional tone arm 5 shown in FIG. Therefore, it is possible to extremely effectively prevent the needle jump phenomenon.

FIG. 4 is an enlarged view for explaining the positional relationship between the tone arm 5 and the turntable 2 in more detail. In the present invention, the starting point R, the intermediate point Q, and the ending point S of the record groove 3 ′ are determined on the radial record center line B passing through the rotation axis C of the turntable 2. The tone arm 5 is positioned such that the tangential direction of the record groove 3 'and the axial direction of the arm shaft 6 coincide with each other at the intermediate point Q in plan view. Therefore, the record center line B is orthogonal to the axial direction of the arm shaft 6 at the intermediate point Q. This intermediate point Q means that the turntable 2 and the virtual circle (second imaginary circle) of the distance D ₀ is the diameter between the rotational axis C and P of the tone arm 5 on the circumference of the D .

That is, the intermediate point Q means a half point (L ₁ = L ₂ = L _0/2 ) of the distance a ₁ a ₂ of the effective width L ₀ of the record groove 3 ′. Shaft core C
The radius R ₀ from to the center portion of the effective width is an amount uniquely determined. Intersection of a first virtual circle W having a radius equal to the distance R ₀ from the rotation axis C of the turntable 2 and a second virtual circle D having a diameter equal to the distance D ₀ between the rotation axes C and P described above. Q becomes an intermediate point Q. Therefore, if the arm shaft 6 of the tone arm 5 is arranged on a straight line PQ connected to the fulcrum P of the pivot portion 8 of the tone arm 5 or on an extension thereof, the tangent of the record groove 3 'near the center of the record groove 3'. The angle difference between the direction and the axial direction of the arm shaft 6 can always be suppressed to substantially zero. This is shown in FIG.
At the intermediate point Q and around the intermediate point Q, the inward and outward component forces applied to the distal end of the arm shaft 6 also become substantially zero.

The start point R and end point S of the record groove 3 '
Then, the tip ends of the arm shafts 6 of the tone arms 5 receive slight component forces in directions opposite to each other. To further reduce the magnitude of this component force, as shown in FIG.
May be sufficiently separated from the position of the intermediate point Q of the groove. That is, the position of the fulcrum P is defined as P ₁ <P ₂ <
It may be far arranged as P _3.

In the record player 1 of this embodiment, when selecting the relative position of the tone arm 5 with respect to the turntable 2, the angle between the tangential direction at the intermediate point Q of the record groove 3 'and the axial direction of the tone arm 5 is determined. An example in which the difference is zero has been disclosed. However, the applicant has determined that the midpoint Q of the record groove 3 '
The occurrence state of the needle jump phenomenon when the tone arm 5 was disposed at a position where the above-described straight line PQ was shifted in parallel with being eccentric inward and outward from the above was examined.

As a result, as shown in FIG. 4, the effective width a ₁ of the record groove 3 ′ on the record center line B passing through the rotation axis C.
It is possible to suppress the needle jump phenomenon at a considerable rate in the area of the central effective width a ₃ a ₄ from the points a _{3 to} a ₄ on the record center line obtained by dividing the space between the points a ₂ into approximately four in the radial direction. Confirmation was obtained. That is, parallel lines P passing through the point _{a 3} '
'In the area of the parallel line P "Q" from passing through the point a _4, the position of the fulcrum P to move the pivot portion 8 of the tone arm 5 parallel line B'B parallel to the record center line B' Q moves on The experiment was performed. As a result, if the fulcrum P is in the region from P 'to P ", the straight type arm shaft 6 is set in parallel with the straight line PQ, so that the needle jump can be performed considerably effectively for the operation of the scratch performance. It was found that this phenomenon could be prevented.

The length of the arm shaft 6 of the tone arm 5 may be sufficiently long as long as it is on the straight line PQ or an extension thereof as shown in FIG. Conversely, the position of the needle 10 may be slightly displaced on the extension line on the Q side. For example, the embodiment of FIG. 3 discloses an example in which the needle tip 10 of the cartridge 9 is slightly displaced on the extension on the side of the intersection Q on the straight line PQ connecting the intersection Q and the fulcrum P in FIG. Therefore, any changes within the scope that can be easily created by those skilled in the art based on the technical concept described in the claims are included in the scope of the present right.

[0031]

FIG. 6 is a diagram for explaining another embodiment, and FIG. 7 is a diagram for explaining a comparative example. In the embodiments of FIGS. 3 to 5 described above, the position of the vertical rotation axis P that enables the arm shaft 6 to rotate in the horizontal direction has been described. However, the actual tone arm 5 also rotates vertically. In this embodiment, a horizontal rotation axis P that enables this vertical rotation is used.
By appropriately setting the position of v, it is possible to further enhance the effects of the embodiments of FIGS. That is, the height of the rotation axis Pv is set higher than the needle tip 10.

In FIG. 6, the load applied to the needle tip 10, that is, the load applied to the record plate 3 when the record plate 3 is at rest is defined as mg. The pivot portion 8 of the arm shaft 6 is provided with a rotation axis P that enables the arm axis 6 to rotate in the horizontal direction and a rotation axis Pv that enables the arm axis 6 to rotate in the vertical direction.

In this embodiment, the rotation axis Pv is deviated more toward the cartridge 9 than P. The rotational axis Pv height of the needle tip 10 is displaced upward by l ₁ than the height of the upper surface of the record sheet 3 other words.

[0034] If the record plate 3 positive and reverse rotation in this case, positive friction force F _F, negative frictional force F _R exerted horizontally needlepoint 10. They are the same size but in opposite directions. These forces F _F, because the direction of F _R are excursion by l ₁ with respect to the rotation axis Pv, the rotational axis P to the arm shaft 6
v the rotational force or torque _T F centered, to generate a _{T R.} Here, T _F = F _F · l ₁ and T _R = F _R · l ₁ .

The torques T _F and T _R apply a vertical force F _F · l ₁ / L and F _R · l ₁ / L to the needle tip 10. Here, L is the distance from the needle tip 10 to the rotation axis Pv. _{F F = mg-F F ·} l 1 at the time of forward rotation in this order needlepoint 10
/ L force is applied downward. Similarly, at the time of reverse rotation, the needle tip 10
, A force of f _R = mg + F _R · l ₁ / L is applied downward.

[0036] Since usually the needle pressure adjuster as needle pressure f _F is the proper value at the time of forward rotation (weight) is set, the needle pressure f _R of the reverse rotation rather than needle pressure f _F of normal rotation (F _R + F _F ) l ₁ /
L increases. Therefore haritobi during reverse rotation will be is prevented, the proper needle pressure f _F which is set at the time of forward rotation. Also by setting the rotational axis Pv at the same height as the tip 10, the torque _T F, since _{T R} becomes zero _{both, f} F = m
g, f _R = mg, and the stylus pressure during forward / reverse rotation can be made the same, which is more preferable.

Here, the effect of this embodiment will be compared with a comparative example shown in FIG. In the one shown in FIG.
Of only l ₂ is positioned lower than the needle tip 10 of the rotational axis Pv for allowing the vertical pivot. In opposite direction to that torque T _F at the time of reverse _rotation, the direction of T _R shown in FIG. 6 in this case. Therefore, the stylus pressure is f _F = m during forward rotation.
g + F _F · l ₂ / L, f _R = mg−F _R · l ₂ at reverse rotation
/ L. Needle pressure during the reverse rotation in the case of setting the needle pressure during forward rotation to a proper value - decreases by _{(F F + F R) l} 2 / L. Therefore, it can be seen that the needle pressure at the time of reverse rotation decreases, and the needle jumps easily occur.

[0038]

FIG. 8 is a view for explaining another embodiment. 8A is a side view, FIG. 8B is a schematic view thereof,
(C) is a front view of the arm shaft 6 as viewed from the cartridge side. In this embodiment, a weight 7A is provided on an extension of the arm shaft 6 on the side of the rotation axis Pv. Here the rotation axis P
v is disposed in a higher position by l ₁ than needlepoint 10 as in the embodiment shown in FIG. 6. Further, the weight 7A is deviated below the rotation axis Pv. In this embodiment, the weight 7A is set at the same height as the needle tip 10.

With such an arrangement, it is possible to balance the balance in a balance shape (a diaper shape) as shown in FIG. That is, the needle pressure f applied to the needle tip 10 and the weight 7
A is lower than the rotation axis Pv. In this case, if the inside force f _i or the outside force f ₀ acts on the needle tip 10 as shown in FIG. 8C, these forces f _i and f ₀ are applied in the direction in which the arm shaft 6 is twisted. Become. However, the presence of the weight 7A suppresses such vibration of the arm shaft 6 in the torsional direction. Therefore, twisting due to the inner component force and the outer component force described with reference to FIG. 3 can be suppressed, and needle jump can be prevented. That is, by combining the embodiment shown in FIGS. 3 to 5 and the embodiment shown in FIG. 6 with the embodiment shown in FIG. 8, it is possible to more reliably prevent the needle jump.

[0040]

In the present invention, even if often rapidly changing the direction of rotation in the normal rotation or reverse rotation of the record sheet by scratching puff _{o-performance} playing form of DJ with record player, record player itself advance the needle Since the structure that suppresses the phenomenon of jumping is considered, even a beginner who does not require skill as in the past can achieve satisfactory DJ performance. For this reason, the DJ performance population can be expanded.

[Brief description of the drawings]

FIG. 1 is an operation explanatory view showing an implementation state of a DJ performance using a conventional HiFi audio record player.

FIG. 2 is a diagram illustrating the operation of a conventional record player.

FIG. 3 is a configuration explanatory view showing a record player according to the first embodiment of the present invention;

FIG. 4 is an explanatory diagram of an arrangement of a turntable and a tone arm in the first embodiment.

FIG. 5 is a conceptual configuration diagram showing another embodiment of the present invention.

FIG. 6 is a diagram illustrating another embodiment.

FIG. 7 shows a comparative example.

FIG. 8 is a diagram illustrating another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Record player 2 Turntable 3 Record board 4 Rotation axis 5 Tone arm 6 Arm axis 7 Needle pressure controller 7A Weight 8 Pivot 9 Cartridge 10 Needle or needle point C Rotation axis of turntable P Support point (horizontal of arm axis) Pv) Rotation axis that enables vertical rotation of the arm axis

Claims (11)

[Claims] 1. A disc jockey record player suitable for a scratch performance operation in which a record board is directly rotated forward and backward by a finger operation of an operator to output a sound, wherein the record player is driven to rotate around a rotation axis C. And a needle that is supported rotatably in the horizontal direction about a rotation axis P located outside the turntable and that follows the rotation axis P and a record groove of the record plate in plan view. An arm shaft positioned on a straight line connecting the arm shaft, and a cartridge that is held at a rotating end of the arm shaft and detects a sound signal by a needle that follows a record groove of a record plate. , Effective width a ₁ a _{2 of} the record groove
A record player characterized by being positioned on a straight line orthogonal to a straight line passing through the rotation axis C of the turntable near the center of the turntable. 2. The record player according to claim 1, further comprising a slip sheet interposed between the record plate and the turntable, the coefficient of friction of at least one surface being small, and facilitating reverse rotation of the record plate. 3. The intermediate axis Q of claim 1, wherein the rotation axis P of the arm axis is orthogonal to a straight line B passing through the rotation axis C of the turntable and the effective width a ₁ a ₂ of the record groove.
Record player located on a straight line passing through. 4. The method of claim 1 or 2, the rotation axis P of the arm shaft, midpoint effective width a ₁ a ₂ of orthogonal and record groove on a straight line B passing through the rotation axis C of the turntable Q
And two points a ₃ and a _{4 that} divide approximately four in the radial direction
Record player located on a straight line passing between The rotational axis P of 5. arm axis, the first virtual circle of the turntable from the rotational axis C of the distance R ₀ substantially to the intermediate point Q between the effective width a ₁ a ₂ a record groove as a radius W and
Rotary shaft cores C and P of turntable and arm shaft
2. The record player according to claim 1, wherein the record player is located on a straight line that passes through an intersection Q with a second virtual circle D having a diameter _equal to a distance D0 of the turntable and that is orthogonal to a straight line B passing through a rotation axis C of the turntable. 6. A start point R and an end point S of a record groove on a straight line B passing through a rotation axis C of the turntable, and the rotation axis P of the arm axis form an isosceles triangle having the rotation axis P as a vertex. The record player according to any one of claims 1 to 3, wherein 7. A record player according to claim 1, wherein the position of the rotation axis P of the arm shaft is located at a position sufficiently distant from the intersection Q. 8. A record player according to claim 1, wherein the arm shaft is extended toward the rotation axis P, and a stylus pressure adjusting device for adjusting the stylus pressure of the stylus is provided at the extension. 9. The record player according to claim 1, wherein the rotation axis Pv enabling the arm shaft to rotate in the vertical direction is positioned higher than the upper surface of the record plate. 10. The record according to claim 9, wherein the rotation axis Pv that allows the arm shaft to rotate in the vertical direction is more deviated to the cartridge side than the rotation axis P that allows the arm axis to rotate in the horizontal direction. Player. 11. A needle pressure adjusting weight whose center of gravity is located below the vertical axis of rotation Pv at an extended portion of the arm axis that extends further away from the cartridge than the horizontal axis of rotation P. The record player according to claim 9, wherein the record player is mounted.