JPS6230164Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a lifting device for a tone arm of a record player.

A conventional automatic record player in which the tone arm is automatically raised and lowered by an arm lifter has already been proposed.

By the way, when the arm lifter is used to automatically raise and lower the tone arm, if the power is turned off or the time switch is turned off, the tone arm cannot be recorded. It is necessary to rotate the cartridge above the record to separate the cartridge's sound needle from the record.

Taking these points into consideration, this idea was designed so that when the power is cut off, the tone arm automatically rotates upward and the tone needle moves away from the record. This is designed to ensure smooth operation.

This device will now be described with reference to the drawings. Reference numeral 1 denotes a base plate (see Fig. 10) which serves as a fixed portion. As shown in Fig. 10, a rotating shaft 3 is rotatably attached to this base plate 1 via a bearing 2, and a tone arm 5 which rotates vertically around a pivot 4 is attached to the upper end of the rotating shaft 3. Thus, as is well known in the art, this tone arm rotates horizontally around the rotating shaft 3 and vertically around the pivot 4. A cartridge (not shown) is attached to the tip of this tone arm.

A shutter plate 7 forming a part of the size sensor 6 is attached to the lower end of the rotation shaft 3. This shutter plate 7 is attached in a plane perpendicular to the axis of the rotating shaft 3. Also attached to this shutter plate 7 is a horizontal drive coil 9 that constitutes a movable portion of a horizontal drive linear motor 8 of the tone arm 5. Although the means for attaching the coil 9 to the shutter plate 7 is not shown, it can be constructed as desired. Further, the coil 9 is constructed so as not to make any contact with the yoke 10b.

The fixed portion of this motor 8 is constructed as described below. In other words, a pair of horizontal drive magnetic yokes 10a and 10b form an arc around the rotation axis 3.
are mounted facing each other at a predetermined distance by assembly bosses (which may be made of magnetic circuit material) 11 at both ends thereof,
Similarly, a magnet 12 having an arc shape centered on the rotating shaft 3 is adhered to the lower surface of one of the yokes, for example 10a, that is, the surface facing the yoke 10b using a suitable adhesive. As shown in FIG. 2, this magnet is magnetized in its thickness direction, thereby creating a DC magnetic field between the pair of yokes 10a and 10b. Although these yokes 10a and 10b are not shown, they are fixed to a suitable fixing part such as a boss 11 to the substrate 1. Therefore, when supplying current in one direction to the coil 9, the shutter plate 7 rotates clockwise around the shaft 3,
When supplying current in the opposite direction, use the shutter plate 7.
rotates counterclockwise, and the tone arm 5 rotates horizontally accordingly.

In this example, a detection device 16 for detecting the rotation speed of the tone arm in the horizontal direction is provided on the opposite side of the rotation shaft 3 from the above-mentioned motor 8. This device 16 can have exactly the same configuration as the motor 8 described above, so a detailed explanation will be omitted. 13a and 13b are arc-shaped magnetic yokes; 14 is an assembly boss for fixing the pair of yokes to a fixed part; 15 is an arc-shaped assembly boss attached to the lower surface of the yoke 13a, that is, the surface facing the yoke 13b; This magnet is also magnetized in the thickness direction in the same way as described above. Reference numeral 17 is a coil similar to the above-mentioned coil 9, and this coil 17 is attached to the above-mentioned shutter plate 7 using a predetermined attachment means. As a result, a voltage proportional to the horizontal rotation speed of the shutter plate 7, that is, the tone arm 5, is obtained from the coil 17, and this is fed back to the circuit (not shown) to prevent the motor 8 from moving suddenly. That's what I do.

Next, the other size sensor main body 18 constituting the size sensor 6 will be explained. This is the fifth
As is clear from the figure, husband plates 19a and 19b are attached above and below the shutter plate 7, and the plate 19
A plurality of light emitting elements 20 are attached to the plate 19b, and a plurality of light receiving elements 21 are attached to the plate 19b facing them. In this example, elements 20 and 21
shows the case where three pieces are provided respectively, and the drawings are shown with suffixes a, b, and c. Therefore, the light from the light emitting element 20a is transmitted to the light receiving element 2.
The light is received at 1a. The same applies to other elements.

By the way, the shutter plate 7 is provided with means for blocking or passing these lights, that is, a slit. In this example, the slit is composed of a first slit 22 and a second slit 23. Of course, these slits 22 and 23 are provided along an arcuate locus centered on the rotation shaft 3 with respect to the shutter plate. An example of the slits 22 and 23 is shown in detail in FIG. 3A. Further, the respective arrangement positions of the above-mentioned light emitting element 20 and light receiving element 21 are also shown in detail in FIG. In addition, in FIG. 3, only the light receiving element 21 is shown, and the element receiving light by the slit is shown by a solid line, and the element not receiving light, that is, the light is blocked, is shown by a dotted line. There is.

Hereinafter, the turning on and off of the light receiving elements by the shutter plate will be briefly explained using FIGS. 3A to 3F, with the element receiving light being 1 and the element being blocked by the shutter plate being 0.

First, FIG. 3A shows a state in which the tone arm is placed on a so-called armrest, and in this case, the element 21a is 0, and the elements 21b and 21c are each 1. Although the circuit is not shown, when the start button is pressed, the shutter plate 7 is rotated clockwise in the figure by the motor 8 mentioned above. Then, the state shown in FIG. 3B is reached, and the three elements 21a, 21b, and 21c each become 1. This state is a so-called lead-in state, and in this state, the above-described rotation of the rotating plate 7 continues.

With this rotation, when the state shown in FIG. 3C is reached, the elements 21a and 21b each become 1, and the element 21c
becomes 0. In this state, the tone arm 5 is in a rotational position corresponding to a 30 cm record.

When the shutter plate 7 further rotates, the element 21a becomes 1 and the elements 21b and 21c become 0, respectively, as shown in FIG. 3D. In this state, tone arm 5 is 25 cm.
The rotation position corresponds to that of a record.

As the shutter plate 7 further rotates, the third
The state shown in Figure E is reached. That is, the element 21a becomes 1, the element 21b becomes 0, and the element 21c becomes 1. In this state, the tone arm 5 is in a rotational position corresponding to a 17 cm record disc.

When the shutter plate 7 further rotates, the state shown in FIG. 3F is obtained. That is, the elements 21a and 21b each have a value of 0, and the element 21c has a value of 1. This state is a preparation state for arm return, but in this state, the shutter plate 7
continues to rotate.

Finally, as shown in FIG. 3G, only when the respective elements 21a, 21b, and 21c are all 0, the tone arm 5 enters the arm return state and is rotated back to above the armrest. be.

Therefore, for example, by manual operation, 30 cm from the outside or
By selecting the size of 25cm or 17cm, the shutter plate 7 can be adjusted to C, D or E in Figure 3, respectively.
At this point, the tone arm stops rotating, and from that point the tone arm drops and performance begins. Of course, each of these sizes is not manually selected, but is automatically selected based on conventional detection means that automatically detects the size of the record placed on the turntable. Figure 3 C or D or E
The shutter plate 7, that is, the tone arm 5, can be rotated in the horizontal direction until the state shown in FIG.

Such a size sensor main body 18 is configured such that the sensor position can be adjusted by a sensor position adjustment device 24.

That is, the size sensor main body 18 is mounted on a movable plate 25, and the movable plate 25 is configured to be able to rotate about the above-mentioned rotation axis 3 with respect to a fixed part, for example, the substrate 1. be.
In the embodiment shown in FIG. 4, a protrusion 26 is further formed integrally with the lower surface of the substrate 1, and a movable plate 25 is slidably attached to the lower surface of the protrusion 26.

As is clear from FIGS. 1 and 6, the movable plate 25 is provided with three long holes 27a, 27b, and 27c, as well as an adjustment hole 28 having a semicircular shape at the front and a rectangular shape at the rear. has been done. The elongated holes 27a, 27b, and 27c are each formed in an arc shape centered on the rotation axis 3 of the tone arm 5 described above, and the symmetrical axis of the hole 28 is on a line passing through the rotation axis 3 described above.

On the other hand, as shown in FIG.
6 has a guide 2 that engages with the elongated holes 27a and 27b.
8a and 28b are provided, and an elongated hole 27
The screw 29 is passed through the part c, and this is the protrusion 2.
is screwed into a screw hole (not shown) formed in 6,
It is designed to tighten the movable plate 25.

Furthermore, a cylindrical adjustment knob 30 as shown in FIG. 8 is provided. 31 is the center hole. On the upper surface of this knob 30, an eccentric cam 32 centered on the center hole 31 is provided integrally with the knob 30.
A stopper 33 is provided integrally with the cam 32, and is formed at the shortest distance from the shaft hole 31 of the cam 32. Then, the hole 28 is adjusted so that the above-mentioned cam 32 is just engaged in the rectangular portion 28a of the position adjustment hole 28 of the above-mentioned movable plate 25.
The size of a is selected, and the size of the hole 28b is also selected so that the stopper 33 just fits inside the semicircular portion 28b of the hole 28.

In this manner, with the cam 32 engaged with the hole 28a, the screw 36 is screwed into the screw hole 37 of the protrusion 26 from the bottom surface of the knob 30, so that the knob 30 is rotatably attached. There is. 35 is a sleeve. Note that 34 is a protrusion formed integrally with the knob 30, and this protrusion 34 makes it easier to rotate the knob 30. Therefore, by rotating this knob 30 clockwise or counterclockwise with the screw 29 loosened, the cam 32 can be moved into the hole 28a.
In order to push this to the left or right while always being in contact with the left and right side surfaces of the
It slides along the loci of 27b and 27c. This is because the slit 2 formed in the size sensor body 18 and the shutter plate 7 explained in FIG.
2 and 23 can be finely adjusted along a circular locus centered on the rotation axis 3. Once the adjustment position is determined in this way, the movable plate 25 can be fixed to the fixed part, that is, the substrate 1, by tightening the screws 29.

Next, we will mainly discuss the device for vertically rotating the tone arm 5 about the pivot 4.
This will be explained using figures. 37 is the arm lifter, and the push rod case 3 is connected to the board 1.
8 is installed, and push rod 3 is installed inside it.
9 is penetrated. Silicone oil is interposed on the contact surface between the push rod case 38 and the push rod 39, making it a so-called viscous material, so that the push rod 39 slides gently against the push rod case 38. is being done. Reference numeral 52 denotes a lifting plate for the tone arm 5 attached to the upper end of the push rod 39.
As shown in FIG. 1, this elevating plate 52 is generally formed in an arc shape with the rotating shaft 3 as the center. A small diameter portion 39a having a predetermined length W is formed at a portion of the lower end of the push rod 39, as shown in FIG.

On the other hand, a seesaw lever 41 is provided which rotates around a fulcrum 40 (in this example, a cylindrical shaft). In this example, the shaft 40 is fixed to a receiving portion 42 attached to the lower surface of the substrate 1 so as to protrude downward. An electromagnetic drive device 43 for vertically driving the tone arm 5 is attached to one end of the seesaw lever 41 . This device 43 is shown in FIGS.
As is clear from the figure, one piece of each of a pair of U-shaped cores 54a and 54b is connected and attached to one end of the seesaw lever 41, magnets 44a and 44b are attached to the other piece of each, and one piece of the U-shaped core 54a and 54b is attached to the other piece of the A solenoid coil 45 is attached to the lower surface of the coil 45, and the connecting body portion of the pair of U-shaped cores 54a and 54b is configured to be able to move freely within the coil 45. Therefore, when a unidirectional current is supplied to the coil 45, the core is configured to move upward within the coil 45 to overcome the weight of the magnets 44a, 44b and the cores 54a, 54b. There is.

The other end of such seesaw lever 41, that is, the tenth
In the figure, the right end engages with the lower end of the push rod 39 of the arm lifter 37 mentioned above. That is, as shown in FIG. 1, a notch 46 is formed at the other end of the seesaw lever 41, and this notch 46 engages in the small diameter portion 39a at the lower end of the push rod 39 as shown in FIG. Furthermore, a spring 47 is wound around this small diameter portion.
7, the other end of the seesaw lever 41 is attached to the lower end of the push rod 39 of the arm lifter 37 in elastic pressure contact. Therefore, the other end of the seesaw lever 41 and the lower end of the push rod 39 of the arm lifter 37 are mechanically connected without any play.

The fulcrum of the seesaw lever 41, that is, the means for attaching it to the shaft 40 is constructed as shown in FIG. That is, both ends of the seesaw lever 41 in the longitudinal direction are bent upward, and this bent portion 49
A triangular window hole 48 is formed in the window hole 48, and the above-mentioned shaft 40 loosely passes through the triangular window hole 48.

Further, the seesaw lever 41 is biased in one direction by a spring 50, so that the shaft 40 is supported at two points (indicated by points 51a and 51b in FIG. 11) against the triangular window hole 48. It has become a state. Therefore, the lever 41 is in a bearing state with respect to the shaft 40 without any play.

In addition, in the case of such bearing means, a circular hole is provided which fits exactly into the cylindrical or cylindrical shaft, and the bearing is normally carried out in a state where both of these are engaged. In fact, since the upper hole must be formed slightly larger, in this case even a slight backlash will occur.

However, with this device, such backlash does not occur at all.

In this configuration, as shown in FIG. 10, the distance from the fulcrum 40 to the magnets 44a and 44b is L, the distance from the fulcrum 40 to the arm lifter 37 is l, and the arm lifter 3 of the tone arm 5 is
The pressing force when the push rod 39 is lowered due to its own weight on the push rod case 38 is taken into consideration as the adhesion force against the push rod 39 due to the silicone oil or viscosity in the push rod case 38, and this is defined as f, and the magnets 44a, 44b and other magnetic yokes 54a, 54b, etc. When the force due to the weight of is F, magnet 44 is set so that FL≧fl
a, 44b, other weights or distances L (or l), etc. are selected. In this case, if a spring 50 is installed on the seesaw lever 41 as shown in FIG. 10, the component force of this spring 50 in the vertical direction (the force that rotates the seesaw lever around the fulcrum 40) is also taken into consideration. Of course, this will happen. By selecting FL≧fl in this way, when the coil 45 is not energized, the seesaw lever 41 rotates counterclockwise and the arm lifter 37 is raised. Furthermore, from conventional experience, the above-mentioned f is f≈100gr.

Furthermore, a detection switch device 53 is formed on the upper surface of the seesaw lever 41. That is, one contact point 53a is formed on the upper surface of the lever 41, and an opposing contact point 53b is formed at the tip of a fixed portion, that is, a protrusion formed on the lower surface of the base plate 1, and the seesaw lever 41 is rotated counterclockwise. In the state shown in FIG. 10, the contacts 53a and 53b are brought into contact with each other, that is, turned on. By turning on the switch device 53, current is supplied to the horizontal motor coil 9. In short, this current is selected to a value that is sufficient to cancel the inside force. Of course, the circuit is not shown in the drawings, but it goes without saying that current for driving the tone arm 5 in the horizontal direction is supplied to this coil 9, and in this example, this coil 9 is used to drive the inside force. This shows a case where cancellation is performed.

According to this device explained above, the shutter plate 7
A horizontal drive coil 9 is attached to the horizontal drive coil 9, and the shutter plate 7 also serves as a drive unit for horizontal rotation of the tone arm 5. There is no need to separately configure the rotating part, reducing the number of parts.
Moreover, it has the feature of being miniaturized as a whole. It also has features such as the component structure can be simplified, assembly is easy, and space is not required.

Further, according to this device, the size sensor main body 18 for the shutter plate 7 is attached to a movable plate 25, and this movable plate 25 is further attached to a fixed part so as to be slidable, and as shown in FIG. With the tightening screw 29 shown in the figure loosened, turn the knob 3.
By rotating the movable plate 25, the movable plate 25 can be finely slid clockwise or counterclockwise about the shaft 3. Therefore, the drop position of the tone arm 5 relative to the record can be easily and finely set by this adjustment device.

Furthermore, in this device, a seesaw lever 41 is provided, and an electromagnetic drive device 43 is provided at one end of the seesaw lever 41.
Therefore, in the performance state, by supplying current to the coil 45, the seesaw lever 41 is rotated clockwise (in FIG. 10; the same applies hereinafter) about the shaft 40, thereby lowering the arm lifter 37.
The tone arm 5 can be brought into contact with a record at a predetermined drop position and played. In this case, if the power is cut off during the performance due to a power outage or the use of a timer, the seesaw lever 41 will rotate around the shaft 40 because the relationship FL≧fl has been selected as described above. The tone arm 5 is rotated clockwise, and the arm lifter 37 rises to push the tone arm 5 upward. That is, the stylus is moved away from the record. This has the feature that it is possible to automatically avoid keeping the stylus tip in contact with the record for a long period of time. Note that when rotating the seesaw lever 41 clockwise by supplying current to the coil 45, the torque FL on the left side of the fulcrum 40 (FL
= Kfl), it is possible to choose K≒2.

Moreover, in this case, the seesole lever 41 is supported without play on the fulcrum 40, that is, the shaft, and the other end of the seesole lever 41 is elastically connected to the lower end of the push rod 39 of the arm lifter 37 via a spring 47. Therefore, for example, when a current is supplied to the coil 45 and the cores 54a and 54b are attracted upward, the seesaw lever 41 moves toward the shaft 4.
The arm lifter 37 can be rotated with no play relative to 0, and since the seesaw lever 41 and the push rod 39 are connected without any play, the arm lifter 37 can be pushed down extremely smoothly. Of course, the same holds true for the reverse operation. By increasing or attenuating the current in a gentle curve using a time constant circuit or the like without causing a sudden change in the current at the moment when the current is turned on or off to the coil 45, the seesaw lever can be further improved. The impact on the tone arm 41 can be alleviated, and the tone arm 5 can therefore move more slowly, allowing for vertical movement with good feeling.

Furthermore, in the past, in order to cancel the inside force, a mechanical force was always applied to the tone arm 5 to rotate outward, but with this device, a switch device is applied to the seesaw lever 41. 53, a current suitable for canceling the inside force is later supplied to the horizontal drive coil 9 at the time when the tone arm 5 is almost dropped onto the record disc. In other words, the canceller current is supplied only while the record is being played, and the canceller current is supplied to the coil 9 when it is not needed.
Since no current is supplied to cancel the inside force, it is possible to easily and smoothly move the tone arm 5 in the horizontal direction during lead-in and return. Since it does not supply electricity, it is useful for reducing power consumption.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing an example of this device;
FIG. 2 is a developed side view of the horizontal drive linear motor 8, FIG. 3 is a plan view showing an example of the size sensor 6, and FIG. 4 is a perspective view from below showing an example of the sensor position adjustment device. Figure 5 is a cross-sectional view of a part of the device, Figure 6 is a plan view showing an example of the movable plate, Figure 7 is a cross-sectional view of a part of the sensor position adjustment device, and Figure 8 is a knob that can be used for this. FIG. 9 is a circuit diagram for an example of an inside force scan cell, FIG. 10 is a sectional view showing a part of FIG. 1, and FIGS. 11 and 12 are respectively diagrams. 10 is an enlarged side view of a portion of FIG. 10. FIG. 5 is a tone arm, 3 is its rotation axis, 8 is a linear motor for horizontal drive of the tone arm, 7 is a shutter plate, 12 is a magnet, 18 is a size sensor body, 4
1 is a seesaw lever, 40 is its fulcrum, 44a and 44b are magnets, and 45 is a vertical drive coil.

Claims (1)

[Claims for Utility Model Registration] 1. A device comprising a seesaw lever that rotates around a fulcrum, an electromagnetic drive device comprising a magnet and a coil provided at one end of the seesaw lever, and an arm lifter engaged with the other end of the seesaw lever. However, when the coil of the electromagnetic drive device is not energized,
In the tone arm lifting device in which the arm lifter is raised by a moment determined by the distance between the electromagnetic drive device and the fulcrum of the seesaw lever, the fulcrum of the seesaw lever has a window hole having a substantially triangular shape. The supporting part is attached to the seesaw lever or the fixing part, and a cylindrical or cylindrical shaft that can pass through the window hole with a margin is attached to the fixing part or the seesaw lever, and the shaft is attached to the seesaw lever. A tone arm elevating device comprising a spring that biases the seesaw lever in a predetermined direction so as to rotate while contacting two sides of the hole. 2. The above utility model registration wherein the other end of the seesaw lever is engaged with the lower end of the shaft of the arm lifter in a state where it is pressed by a spring that is wound around the shaft and one end of which is in contact with the shaft. A tone arm lifting device according to claim 1.