JPS6122402A - Muting controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a muting control device that can detect when the stylus has passed between songs while playing a record, close muting, and cut off audio signals. It is something.

Conventional configurations and their problems In recent years, as audio devices have become more multifunctional, music selection functions have been added to record and chord players, and there has been an increasing demand for lower prices.

A conventional muting control device will be explained below.

FIG. 1 shows a block diagram of a conventional muting control device, in which 1 is a motor, 2a and 2b are deceleration worm gears, 3 is a rope, 4 is an arm base, 5 is a pickup arm, 6 is a cartridge, 7 is a reflected light sensor installed near the cartridge, 8 is a control unit such as a microcomputer, 9 is a pulse generator that generates pulses according to the rotation of motor 1, and 1o is used to open and close muting. This is a muting circuit that can be used.

The operation of the conventional muting control device configured as described above will be described below.

First, the motor 41 rotates and is decelerated by the gears 2a and 2b, and the arm base 4 is moved in parallel by the rope 3.
While proceeding from the outer circumference to the inner circumference, a reflected light sensor 7 installed near the cartridge 6 detects a gap between songs based on the difference in reflectance. When the reflected light sensor 7 is moving over the sound groove of a record, that is, a place where the feed pitch is small and the reflectance is low, the reflected light signal output is small, and the reflectance is relatively large due to the large feed pitch between songs. When the reflected light sensor 7 is moving over a place, its signal output is large.

The controller 8 stores the number of pulses output between songs by the pulse generators such as the shutter disk 9C and the photointerrupters 9a and 9b in accordance with the rotation of the motor 1. When playing a record, the motor 1 is controlled so that the arm base 4 moves inward following the sound groove of the record, but when the reflected light sensor 7 detects the song interval and the needle falls onto the record, The pulses output by the pulse generating section 9 are input to the control section 8, and the control section 8 compares them with the number of pulses stored in advance. At the moment when the needle traces the sound groove and the number of pulses matches at the end of the performance song, the control section 8 determines that the cartridge 6 has reached the interval between songs on the record, and the muting circuit 10
close to cut off the audio signal.

However, with the above configuration, since the actual distance traveled on the record depends only on the number of pulses stored in advance, the drop position may shift due to eccentricity of the record or inadequate adjustment of the drop position. However, if the needle falls before or after a song, the muting cannot be accurately closed between songs, resulting in the end of the song being played and the beginning of the next song. was.

Purpose of the Invention The present invention solves the above-mentioned conventional problems, and provides muting control that can reliably detect passage between songs regardless of the needle's falling position and close the muting row based on the detection result. The purpose is to provide equipment.

Structure of the Invention The present invention includes a pickup arm, an arm drive unit that moves the pickup arm in the radial direction of a record, a pulse generator that generates pulses as the pickup arm moves, and
The pickup arm is equipped with a speed detection circuit that detects the moving speed of the pickup arm while the record is being played, and a reflected light sensor that is installed near the pickup arm and detects the intervals between songs on the record, so that the pickup arm follows the grooves of the record. The arm is moved, and the speed detection circuit starts detection from before the track gap on the record optically detected by the reflected light sensor, and the pickup arm passes through the track gap on the record based on the detection signal. This is a muting control device that can detect when the pickup arm is moving at a certain speed or higher and close the muting circuit and cut off the audio signal. Regardless, it is possible to reliably detect passage between songs and close the muting circuit.

DESCRIPTION OF THE EMBODIMENT FIG. 2 shows a block diagram of a muting control device in an embodiment of the present invention. In Figure 2, 1
.about.1o are the same as those in FIG. 1, so their explanation will be omitted. 11
is a speed detection circuit that detects when the arm base 4 reaches a certain speed or higher based on a pulse signal from the pulse generator 9.

The process up to the detection of the song interval by the reflected light sensor 7 is the same as the conventional example, and will therefore be omitted.

During the performance of a record, the speed detection circuit 11 starts detecting the moving speed of the pickup arm 5 by the output pulse from the pulse generator 9 before the song interval detected by the reflected light sensor 7. When the stylus is tracing a normal sound groove, the period of the output pulse from the pulse generator 9 is long, for example, about one pulse per revolution of the record, but when tracing a rough part between songs. The period becomes shorter. Therefore, the speed detection circuit 11 can be set to generate a detection signal only when the period of the output pulse from the pulse generator 9 is short.

Based on the detection signal, the control section 8 knows that the cartridge 6 is passing between songs on the record, and can close the muting circuit 10 and cut off the audio signal.

As described above, according to this embodiment, the speed detection circuit 11 is set to generate a detection signal only when the period of the pulse output from the pulse generator 9 as the pickup arm 6 moves is short. For example, from the detection signal, the control unit 8 can know that the cartridge 6 is passing between tracks on the record, and can close the muting, thereby preventing the drop position from shifting due to eccentricity of the record or improper drop position adjustment. Even if this occurs, the muting can be accurately closed between the next songs, and the problems of running out of the performance song and starting the next song can be solved.

Effects of the Invention The present invention is equipped with a speed detection circuit that detects when the moving speed of the pickup arm exceeds a certain speed while playing a record. If the speed detection circuit is set to generate a detection signal only when the speed detection circuit is moving, the detection signal can be used to determine that the cartridge is passing between songs on the record, and the muting circuit can be closed. Therefore, even if the drop position shifts due to eccentricity of the record or incorrect drop position adjustment, it is possible to reliably detect the passage between songs and close the muting, resulting in the end of the song being played or the request 9 of the next song. It is possible to realize an excellent muting control device that can solve the problems.

[Brief explanation of drawings]

Figure 1 is a block diagram of a conventional muting control device.
FIG. 2 is a block diagram of one embodiment of the present invention. 1... Motor, 2... Reduction gear, 3...
...Rope, 4...Arm base, 5...Pickup arm, 6...Cartridge, 7...
・Reflected light sensor, 8...Control unit, 9...
- Pulse generation section, 1o...muting circuit, 11...speed detection circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
figure

Claims (1)

[Claims] A pickup arm, an arm drive unit that moves the pickup arm in the radial direction of the record, a pulse generator that generates pulses as the pickup arm moves, and a speed that detects the speed of movement of the pickup arm while the record is being played. It is equipped with a detection circuit, a reflected light sensor installed near the pickup arm to detect the interval between songs on a record, and a muting circuit controlled by the output of the speed detection circuit. The pickup arm is moved to follow the groove, and the speed detection circuit starts detecting the moving speed of the pickup arm from the front of the track interval on the record optically detected by the reflected light sensor. It detects that the moving speed has exceeded a predetermined speed, uses the detection signal to detect that the pickup arm has passed between songs on the record, and closes the muting circuit.
A muting control device characterized by cutting off an audio signal.