JPH0239003B2 - JIDOSENKYOKUPUREEYANOKYOKUNOSHUTANKENSHUTSUSOCHI - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is an automatic system that detects the gaps between songs on a record with an optical sensor by using the fact that the reflectance of light is different from that of the sound grooves, and plays any song. Regarding the music selection player.

Conventional configuration and its problems Conventionally, in automatic music selection players, before starting automatic music selection performance, an optical sensor moves over the record, detects an interval between songs, stores the inter-music position in a storage device, and automatically selects a song. When you start playing a selected song, the pick-up is moved to the inter-song position stored in the storage device, then lowered to find the beginning of the song, and when the pick-up moves to the next inter-song position stored in the storage device,
It was designed to assume that the end of a song was reached, raise the pick-up, and move on to the next song to be played. However, in general, some records have eccentric grooves and center holes (hereinafter referred to as eccentric records), so if you casually lower the pick-up at the first detected inter-track position, the inter-track position will be on the record. Problems arise in that it is shifted due to rotation and cannot be lowered to the correct position between songs, and the end of a song cannot be detected correctly.

Therefore, Japanese Patent Application No. 57-126961 (Japanese Patent Application No. 59-126155)
(Refer to the publication), the optical sensor is activated near the interval between songs when the automatic song selection starts. After the optical sensor detects the interval between songs, when the detection point is exactly under the tip of the pick-up needle, the needle is activated. It has been proposed to time the descent of the pick-up so that it will land on the ground. By using this method, the tip of the pick-up can be correctly lowered to the inter-track position even on an eccentric record, but when the pick-up moves inward by the amount of eccentricity and reaches the next inter-track position stored in the storage device, The pick-up increases because it is considered to be the end of the song. That is, eccentric records have the disadvantage that the end portion of the song cannot be played because it is erroneously detected that the end of the song has been played before the end of the song has been played.

OBJECTS OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned drawbacks and to make it possible to correctly play until the end of a song even with an eccentric record.

Composition of the Invention The present invention comprises a pickup, an optical sensor that moves in conjunction with the pickup, a position detection means for detecting the position of the pickup, a storage device for storing inter-musical positions, and a pickup until the end of a song when automatically selecting and playing a song. A device for detecting the end of a song in an automatic music selection player, which is equipped with a logical means for generating a signal to end the performance when played, corrects the playing distance when playing an eccentric record so that the vicinity of the end of the song is not missed. This allows the player to play until the end of the song correctly.

DESCRIPTION OF EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an embodiment of an automatic music selection player using the present invention. In the figure, 1 is a turntable on which a record is placed and played with a pickup 2. The pick-up 2 is mounted so that it can be raised and lowered by a lift 3 that rotates around a bearing 4. The lift 3 is driven by a plunger (not shown), the bearing 4 is coated with high viscosity oil, and the pickup 2 is configured to slowly rise and fall.

On the other hand, the pick-up 2 has pulleys 6a to 6.
d. A rope 5 is attached through a drum 8 that is integrated with the worm gear 7, and when the motor 9 rotates, the worm 10, the worm gear 7, the drum 8,
The pick-up 2 is configured to be moved by transmitting power to the rope 5. Also, on rope 5,
An optical sensor 11 that moves in conjunction with the pick-up 2 is attached. Reference numeral 12 designates a micro switch for determining the reference position of the pick-up 2, which is turned on when the pick-up is located at the outermost circumference of the record, and turned off at other positions. Further, 13 is a photo interrupter which, in cooperation with a slit plate 14 attached to the shaft of the motor 9, generates a number of pulses corresponding to the amount of movement when the motor 9 rotates and the pickup 2 and the sensor 11 move. It constitutes a position detecting means.

FIG. 2 is a block diagram of the control circuit of the automatic music selection player of the present invention. As shown in the figure, the outputs of the microswitch 12 and photointerrupter 13 are input to a microcomputer 15. Also, optical sensor 1
The output of 1 is input to the microcomputer 15 via the filter amplifier 16. The microcomputer 15 includes a storage memory and an arithmetic circuit, and its output is applied to the motor 9 via a control circuit 17 for the motor 9, and to a plunger 19 for raising and lowering the lift 3 via a plunger drive circuit 18.

Next, the operation of this automatic music selection player will be explained.
First, with the turntable 1 stopped, the optical sensor 11 moves on the record from a reference position where the switch 12 is turned on to the innermost circumference while detecting the intervals between songs. FIG. 3 shows the output of the optical sensor at that time.

The distance from the reference position until the inter-song pulse is input to the microcomputer 15 is detected as a digital quantity by counting the pulses input from the photo interrupter 13, _l1 , _l2 , _l3 , _l4 , This is stored in the memory within the microcomputer 15.

FIG. 4 is an explanatory diagram when an eccentric record disc is used. For example, in the case where only the second song is played, the optical sensor moves from the reference position until it finds the first song interval and then stops.
If an eccentric record disc is used, even if the song interval 20 comes under the optical sensor 11, the pick-up stylus tip 2a will not necessarily be at the song interval 20 position. Therefore, if the pickup 2 is lowered carelessly, it will not be lowered correctly to the song interval 20.
Since the turntable 11 is rotating, the timing is set so that when the turntable rotates by the angle difference α between the sensor 11 and the stylus 2a of the pick-up 2, or 360°+α, the stylus 2a of the pick-up falls onto the record. If they are lowered at the same time, since the song space 20 has been moved to the song space 20', they will descend exactly to the song space 20'.

Next, in the conventional system, the signal for ending the performance of the song is generated by a tracking control means (not shown) after the pickup 2 descends, and the motor 9 is rotated so that the pickup 2 follows the sound groove. , it was generated when the pick-up 2 moved by l ₂ −l ₁ , but as shown in FIG. (up to the maximum point inside the eccentricity), the pick-up 2 moves by x. In the conventional method, the width of the song would be shortened by x, making it impossible to play near the end of the song.

In the present invention, after the tip 2a of the pick-up reaches the track interval 20' at a distance of l ₂ - l ₁ , the motor 9 is rotated by the tracking control means (not shown) so that the pick-up 2 follows the sound groove. Then, the microcomputer is configured to detect the distance traveled in a certain period of time (approximately 1.8 seconds) by a position detection means composed of a slit plate 14 and a photo interrupter 13, and to end the performance when the pickup 2 has moved by the sum of the distance. 1
In this way, the performance can be correctly played to the end and then terminated.

Also, if you add up the distance that the pick-up moves within a certain amount of time, in many cases the pick-up will move between songs even when playing a record with no eccentricity, since one revolution is sent at a large pitch between songs. This results in the inconvenience of adding up the distance between the songs, and conversely causing the possibility of playing the beginning of the next song. Therefore, a fixed value (approximately 0.3mm), and if the result is positive, add it to l ₂ - l ₁ and get 0.
If it is below, the eccentricity is sufficiently small, so if we use a logic that does not add anything, we can reduce the possibility of playing the beginning of the next song.

Effects of the Invention As described above, according to the song end detection device of the present invention, even when playing an eccentric record with an automatic song selection player, the playback does not end in the middle of the song, and the song can be played correctly. You can play until the end.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of an automatic music selection player according to the present invention, FIG. 2 is a block diagram of its control circuit, and FIG. FIG. 4 is an output waveform diagram when the optical sensor moves over the record, and is an explanatory diagram of the operation when an eccentric record is used. 1... Turntable, 2... Pickup,
2a...Pickup needle tip, 3...Lift, 4
...Bearing, 5...Rope, 6a-6d...Pulley, 7...Worm gear, 8...Drum, 9...
Motor, 10... Worm, 11... Optical sensor,
12... Switch, 13... Photo interrupter, 14... Slit plate, 15... Microcomputer, 1
6...Filter amplifier, 17...Motor control circuit, 18...Plunger control circuit, 19...Plunger, 20, 20'...Between records.

Claims (1)

[Claims] 1. A pickup that moves on the record, an optical sensor that moves on the record in conjunction with the pickup, a position detection means that detects the position of the pickup, and a pickup that moves on the record before automatically selecting a song. a storage device for storing a signal corresponding to a position between songs outputted from the position detecting means when moving on the record and detecting a gap between songs; When the pick-up reaches the position between songs, it stops moving and lowers the pick-up stylus between the songs. Almost 1 board
If the distance traveled by the pick-up during the rotation time is equal to or greater than a certain value, the distance calculated by subtracting the certain value and adding it to the song width obtained by calculating the result from the contents stored in the storage device, or the certain value If the pick-up is smaller than the width of the song, the end of the song is determined to be the end of the song when the pick-up moves by the song width, and a logic means outputs a signal to raise the pick-up.