JPS5822825B2 - player device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a player device equipped with a sensor for detecting sound grooves and silent grooves of a record.

In an automatic performance player, in order to control the cartridge arm and drop the cartridge arm to the beginning of a desired song, a sensor that detects the presence or absence of a tone groove or a silent groove is absolutely necessary.

This sensor is equipped with an LED as a light emitting part and a phototransistor (PT) as a light receiving part.The light from the LED is irradiated onto the record surface, and the reflected light is received by the PT and converted into an electrical signal. , a common method is to detect silent grooves.

It goes without saying that it is most desirable for the sensor to be located at the tip of the stylus in order to lower the record stylus to the position of the desired song. It is structurally unreasonable to attach it to this position.

Therefore, the next best option would be to mount the sensor at least on the tracing trajectory of the record stylus, slightly to the side of the stylus, but in this case, a means to compensate for the difference in position between the sensor and the stylus tip would be required. .

What is more problematic is a position like this (near the needle)
In order to attach a sensor to a cartridge, the sensor must be attached to the cartridge shell, and the number of terminals at the electrical connection between the cartridge and the arm increases, which limits the number of cartridges that can be used and makes it less compatible with commercially available cartridges. It is something that can happen.

Therefore, in order to solve this problem, the present invention aims to provide a player device that is provided with a sensor arm that is provided with a sensor separately from a main arm that includes a cartridge.

In addition, there is a method for establishing a one-to-one correspondence between the two arms (main arm, sensor arm), which is a problem in such a player device, for example, by determining the detection positions of the two arms, that is, on the record. This provides a means for making the detection counts on the same circumference match as much as possible between the two arms.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a top view of a player device which is an embodiment of the present invention;
FIG. 2 is a side view (partial) of the same.

In the figure, 1 is the player board, 2 is the main arm, and 3
is a cartridge (stylus), 4 is a turntable and record disc, and PM is a phono motor.

The above are the main components of a conventional player.

5 is a sensor arm, and a sensor 6, which is a combination of LED and PT, is attached to the tip of this arm.

This arm is connected by a shaft 7 to a motor 8 mounted on the underside of the board and a gear 9.

Therefore, when voltage is applied to the motor 8, the sensor 6 sweeps over the record in an arcuate locus shown in FIG.

Similarly, the main arm 2 can also be controlled horizontally through a motor 10 and a gear 11.

Of course, a so-called arm lifter operation is required before and after horizontal movement, but this is omitted since it is not directly relevant to this explanation.

Shutters 12 and 13 are attached to the shaft of each arm, each having fine slits, and the shutters 12 and 13 rotate as the shaft rotates.

Each of the shutters 12 and 13 has a finely slit cut into it, and pulse sensors 14 and 15 are placed between the shutters 12 and 13.
is installed, and this pulse sensor 14. IS has an LED light emitting section on the top and a PT light receiving section on the bottom, facing each other, and emits a pulse every time the light is blocked by the shutters 12 and 13.

Here, there is a counter that counts the pulses obtained by the pulse sensor 15 as the main arm 2 is rotated toward the center of the record disc 4, and a counter that counts the pulses obtained by the pulse sensor 15 as the main arm 2 is rotated toward the center of the record disc 4. There is a counter that counts the pulses received.

Note that in the case where the sensor arm 5 is rotated first and the main arm 2 is rotated after the rotation is completed, the counters for the pulse sensors 14 and 15 may of course be the same.

The shutters 12 and 130 slits are carved so that the count number when the cartridge 3 is brought to a certain groove on the record disc 4 is the same as the count number when the sensor 6 is brought to the same groove. Make it.

By the way, when performing automatic performance using a device equipped with such a main arm 2 and sensor arm 5, the following process can be considered, for example.

First, turn on the switch and store the desired song number in the circuit or microprocessor.

Next, when the start button is pressed, the sensor arm 5 first sweeps over the record to near the center of the turntable.

At this time, the sensor 6 monitors the presence or absence of the silent groove, and at the same time the pulse sensor 1 detects the light pulses associated with the shutter rotation.
4 is detected and counted using a separate counter.

The circuit element sequentially stores the count number when the silent groove output of the sensor 6 is outputted in the memory.

For example, it is stored as shown in Table 1.

Next, main arm 2 starts moving.

The pulse sensor 15 counts the pulses obtained during the movement, and if this count is set as N2, the movement is stopped at an appropriate point and the performance is started by referring to the count number N2 stored by the sweep of the pulse sensor 14.

For example, when the second song is specified, N1 is '0183'.
It is simple in terms of circuit configuration to start playing when the signal reaches ``0250'' and end the performance when the signal reaches ``0250''.

In this case, the count number Nl is when the sensor 6 and the cartridge 3 are placed on the same circumference of the record.

It is necessary that N2 match.

In particular, the grooves on records are extremely thin, so it takes N1.00 to lower the cartridge to the desired song. A strict match of N2 is required.

However, counting methods that match the two would be extremely difficult and complicated using other methods.

In FIG. 3, the axial center P of the main arm 2 and the axial center Q of the sensor arm 5 are point symmetrical with respect to the center 0 of the turntable, and the lengths of the needle tips A and P, AP and the sensor C
Only when the lengths σ and Q are equal and the reference lines PA and QC match, the angles ZAPB and ZCQD made with respect to the circumferences B and D on which the record is located match.

However, in reality, due to the structure and performance of record players, P and Q cannot always be point symmetrical with respect to O.
Furthermore, it is often not possible to make the QC the same length as the AP.

If P and Q are not at the symmetrical point and AP = QC, then the angles /APB and ZCQD made with respect to B and D on the same circumference do not match, of course, but the relationship is expressed by a simple relational expression of addition, subtraction, multiplication, and division. Mutual conversion is not possible without using complex relational expressions that include sin and cos.

The greatest feature of the present invention is that by counting the rotation angles of both arms using slits, the rotation angles of both arms and the number of counts can be exactly matched without the troublesome conversion described above.

A specific example is the shutter 13 attached to the main arm 2.
The slits are equally spaced slits of %0 (the extension lines of each slit intersect on the axis of the main arm 2.

). and ZC for ZAPB at each angle
The QD is determined by calculation or actual measurement, and an original version of the slit of the shutter 12 is made based on this angle.

Based on this original plate, precise slits can be created using photographic technology, and the correspondence (for example, rotation angle) of both arms can be easily matched.

This matching allows the counts by the counter to match when the main arm 2 and sensor arm 5 are placed on the same circumference of the record, and the interrelationship of the counts can be made to have a specific relationship. can do.

In this way, the correspondence between the positional information obtained by the sweep of the sensor arm 5 (positional information corresponding to the silent groove, the sound groove, etc.) and the positional information obtained by the sweep of the main arm 2 can be realized.

As described above, according to the player device of the present invention, an arm separate from the arm provided with the cartridge is provided independently;
The slits provided in the light shielding body that are linked to the movement of these arms are formed so that when both arms are brought to the same circumference of the record, the positional information obtained in relation to the slits will match or have a specific relationship. Therefore, it is possible to control the arm equipped with the cartridge based on the position information obtained in relation to another arm, which is extremely useful for controlling the player device. The arm equipped with the cartridge has a slight effect on the sound quality, but this can be avoided by interlocking the light shielding plate with the arm, which reduces the negative impact on performance and improves cartridge compatibility. .

[Brief explanation of drawings]

FIG. 1 shows a top view of an embodiment of the player device of the present invention, FIG. 2 shows a cross-sectional view of the same, and FIG. 3 shows an explanatory diagram illustrating the operation of the same. 2: Main arm, 3: Cartridge, 5: Sensor arm, 6: Sensor, 8: Sensor arm 1 drive motor, 10: Main arm, drive motor, 12.13: Shutter, 14, 15: Pulse sensor/sensor.

Claims (1)

[Scope of Claims] 1. A main arm equipped with a cartridge; a sensor arm provided independently of the main arm, capable of moving over a record disc, and equipped with a sensor for detecting silent grooves on the record disc; a first pulse sensor that outputs pulses in accordance with the movement of the main arm when it moves toward the center of the record; and a first counter that counts the pulses and obtains position information of the main arm. a second pulse sensor that detects pulses as the sensor arm moves toward the center of the record; a second counter that counts pulses output from the second pulse sensor; a memory for storing the number of count pulses of the second counter as position information of the silent groove when detecting the silent groove on the record; Then, the main arm is moved toward the center of the record until the position information of the main arm of the first counter matches the position information of the silent groove in the memory. By the way, the player device that started playing.