JPS641841B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field The present invention relates to improvement of a record player, and in particular, the present invention relates to an improvement of a record player. The aim is to enable the use of (b) Background of the Technology A fully automatic record player with automatic music selection is known that uses a cartridge equipped with a sensor configured by a photocoupler that combines a light emitting diode and a phototransistor. The sensor is provided to detect silent grooves between songs on a record by projecting light (infrared rays) generated from a light emitting diode onto the record and receiving the reflected light with a phototransistor. On a record, the reflectance is small in the sound grooves and large in the silent grooves, so it is possible to detect the silent grooves by detecting the current flowing through the phototransistor according to the reflected light, and also to calculate the number of silent grooves. By counting, it is possible to selectively play an arbitrary number of songs. The sensor is also normally used to determine the stop position of the tone arm during auto-start. In other words, when auto-starting, push the start button to operate the start circuit and move the tone arm over the record, but at this time the phototransistor of the sensor detects the strong reflection of light from the edge of the record. As a result, the tone arm is stopped above the introduction groove of the record. Therefore, when you press the start button when using a cartridge without a sensor, the tone arm does not stop above the lead-in groove of the record, but moves to the center of the record, and then returns to the rest position using the auto-return mechanism. It was causing an abnormal movement of returning. (C) Summary of the Invention The present invention has been made in view of the above-mentioned points, and controls the inhibit circuit using a signal generated when using a cartridge equipped with a sensor, so that the start circuit operates normally, and also enables the start circuit to operate normally. When using a cartridge with a sensor, the inhibit circuit is activated and the start circuit is deactivated, so that when a cartridge with a sensor is used, the record player is turned into a fully automatic player with automatic music selection. When using a cartridge without a sensor, the record player is intended to operate as a semi-automatic player. (d) Embodiment FIG. 1 is a circuit diagram showing an embodiment of the present invention.
1 is a sensor consisting of a light emitting diode 2 and a photodiode 3 disposed inside the cartridge; 4;
5 is a resistor that becomes a current path for the current flowing through the light emitting diode 2 when the cartridge is coupled to the tone arm; 5 is a first transistor 6 and a second transistor 7 that are turned on and off according to the voltage across the resistor 4; Prohibition circuit, 8 is the start circuit of the record player, 9 is also the repeat circuit, 10
Reference numeral 11 indicates a start switch for operating the start circuit, 11 indicates a repeat switch for operating the repeat circuit 9, and 12 indicates a control signal of "H" or "L" depending on the current flowing through the phototransistor 3. In the control circuit that generates the signal, the output terminal of the inhibition circuit 5 is connected to the input terminals of the start circuit 8 and the repeat circuit 9. If the cartridge with sensor is connected to the tone arm, the power supply voltage (+B) is supplied from the terminal 13a to the terminal 13b, and the current flows to the light emitting diode 2 via the terminals 14b and 14a and the resistor 4. flows. Therefore, the light emitting diode 2 emits light and projects the light onto the record player. At that time, the voltage across the resistor 4 becomes a predetermined value, the first transistor 6 is turned on, and the second transistor 6 is turned on.
Since the transistor 7 is turned off, the inhibit circuit 5 does not affect the start circuit 8 and the repeat circuit 9. Therefore, if the start switch 10 is closed in this state, a positive voltage is applied from the power supply to the input of the start circuit 8 via the start switch 10,
The start circuit 8 starts operating. When the start circuit 8 starts operating, the turntable rotates, and the tone arm rises at the rest position and rotates horizontally. While the tone arm passes over the top of the record player, there is little reflected light, so
The current flowing through the phototransistor 3 is small, and the output of the control circuit 12 is at "L". As the tone arm continues to rotate horizontally and reaches the edge of the record, the reflected light increases and the phototransistor 3
The current flowing through becomes large and the output of the control circuit 12 becomes "H". Therefore, in response to the generation of the output "H", the stop circuit is activated to stop the horizontal rotation of the tone arm, and then the tone arm is lowered to start playing. Furthermore, if the repeat switch 11 is closed, the tone arm will rise at the rest position and rotate horizontally, similar to when the start switch 10 is closed.
It descends in the lead-in groove of the record, and the performance begins.
Thereafter, the tone arm rises in the lead-out groove of the record, rotates horizontally in the opposite direction to above the lead-in groove, and then descends again to perform a repeat performance. Therefore, when a sensor-equipped cartridge is used, the record player operates normally as a fully automatic record player with automatic music selection. Next, the case of using a cartridge without a sensor will be explained. The sensorless cartridge has only four connection pins 16, 17, 18 and 19 for left and right stereo signals, which are arranged in standardized positions, as shown in FIG. (Naturally, the sensor-equipped cartridge also has four such connection pins, but
It is omitted in FIG. ) Therefore, when a cartridge without a sensor is connected to the tone arm, the terminals 13a, 14a and 15a in FIG. 1 are in an open state, and the base voltage of the first transistor 6 of the inhibiting circuit 5 becomes zero. Therefore, the first transistor 6 is turned off and the second transistor 7 is turned on, and the input terminals of the start circuit 8 and the repeat circuit 9 are grounded by the collector-emitter path of the second transistor 7. Therefore, even if the start switch 10 or the repeat switch 11 is pressed, the start circuit 8 or the repeat circuit 9 will not operate, thereby preventing abnormal operation of the tone arm. In the embodiment shown in FIG. 1, since the start circuit 8 and the repeat circuit 9 are operated by a positive signal, the input ends of the start circuit 8 and the repeat circuit 9 are grounded by the inhibit circuit 5 . However, if the start circuit 8 and the repeat circuit 9 are of a type that operates by grounding the input terminal, for example, the collector of the first transistor 6 is stopped by the start circuit. When connected to the circuit 8 and the repeat circuit 9 and using a cartridge without a sensor, inhibition can be effected by turning off the first transistor 6 and applying a positive voltage. (e) Effects As described above, according to the present invention, it is possible to switch the record player between an automatic music selection fully automatic record player and a semi-automatic record player by simply replacing the cartridge. This is an excellent device that provides the advantage that the cartridge without the sensor can be used easily, and that the tone arm does not operate abnormally when using the cartridge without the sensor.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a plan view showing the connection pin arrangement of a cartridge without a sensor. Explanation of the main drawing numbers: 1 ...Sensor, 5 ...Prohibition circuit, 8...Start circuit, 10...Start switch.

Claims (1)

[Claims] 1. A start circuit for automatically starting a performance upon operation of a start button in a record player having a tone arm configured to connect a cartridge with a sensor and a cartridge without a sensor, and a start circuit for making the start circuit inoperable. When the cartridge with the sensor is connected to the tone arm, the start circuit is brought into a normal operating state, and when the cartridge without the sensor is connected to the tone arm, A record player characterized in that the start circuit is made inoperable by activating the prohibition circuit.