JP2544441Y2 - Small playback equipment - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] In this invention, a switch is switched in conjunction with a volume control volume of headphones so that a headphone output and a line-out output can be shared by one mini jack. A small playback device.

[Technical background of the invention]

2. Description of the Related Art Conventionally, a block diagram relating to an output terminal of a small-sized reproduction device is usually as shown in FIG.
In the figure, reference numeral 1 denotes a line amplifier for amplifying a reproduction signal. The output terminal of the line amplifier 1 is connected to a line output pin jack 5 via resistors R1 and R2.

The connection point between the resistors R1 and R2 is grounded via a variable volume for volume control. The movable terminal of the variable volume 4 is connected to the input terminal of the headphone amplifier 2. The output terminal of the line amplifier 2 is connected to a stereo mini jack 3 via a resistor R3.

 Next, the operation will be described.

The reproduced signal of the small signal from the terminal a is amplified by the line amplifier 1 and guided to the line output pin jack 5 as an appropriate reproduced output via the resistors R1 and R2.

Further, the headphone output is selected to an appropriate reproduction output by the variable volume 4 and amplified by the headphone amplifier 2, impedance-matched by the resistor R3, guided to the stereo mini jack 3, and supplied to headphones (not shown). You.

[Problems of background technology]

As shown in FIG. 2, a conventional small-sized reproducing apparatus is equipped with a line output pin jack 5 and a stereo mini jack 3.

There are also small devices equipped with two separate mini jacks for line output and headphone.

Small-sized playback devices often use headphones because they listen while moving, but it is natural and convenient to provide an output terminal with a different purpose depending on the usage condition.

However, as the miniaturization of the equipment progresses, the two output terminals become large and take up space, which hinders the miniaturization of the equipment.

[Purpose of the invention]

This invention has been made in order to eliminate the above-mentioned conventional drawbacks, and has as its object to provide a small-sized reproduction device in which a headphone output and a line-out output can be shared by one mini jack, and the size can be reduced. I do.

[Outline of the invention]

In the compact reproducing apparatus of the present invention, the reproduced signal is amplified by the first amplifier, the volume of the output signal of the first amplifier is adjusted by the variable volume, and the output according to the variable volume is amplified by the second amplifier. In addition, two or more output terminals are switched by a switch in conjunction with the variable volume.

[Example of the invention]

Hereinafter, an embodiment of the small-sized reproduction device of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of one embodiment. In FIG. 1, the same parts as those in FIG.

The reproduction signal introduced to the terminal b is amplified by the line amplifier 1. The output terminal of the line amplifier 1 is connected to the fixed terminal d of the volume interlock switch 7 via the resistors R4 and R5. The movable terminal of the volume interlock switch 7 is connected to the stereo mini jack 3.

The connection point between the resistors R4 and R5 is connected to the collector of the transistor 8. The emitter of the transistor 8 is grounded, and the base is connected to the terminal c via a resistor R7.

The connection point between the resistors R4 and R5 is grounded via a variable volume switch 6. The movable terminal of the variable volume switch 6 is linked with the movable terminal of the above-described volume interlock switch 7.

This switch does not show the switch of the variable volume 6. The movable terminal of the variable volume switch 6 is connected to the input terminal of the headphone amplifier 2, and the output terminal of the headphone amplifier 2 is connected to the fixed terminal e of the volume interlock switch 7 via the resistor R6.

Note that signals of other channels are also introduced into the stereo mini jack 3.

In addition, when the volume of the variable volume switch 6 is minimized, the volume interlock switch 7 is closed to the fixed terminal d side, and when the volume is rotated in the maximum direction even slightly more than the minimum, the volume interlock switch 7 is switched to the fixed terminal. The switch is configured to fall to the e side.

Next, the operation of the small-sized reproduction device of the present invention configured as described above will be described.

The reproduction signal of the small signal from the terminal b is amplified by the line amplifier 1, reaches an appropriate output level via the resistors R4 and R5, and is output to the fixed terminal d of the volume interlock switch 7.

If the variable volume with switch 6 at this time is in the minimum state, the movable signal of the volume interlocking switch 7 is on the fixed terminal d side, and the reproduced signal is output to the stereo mini jack 3 through the resistor R5. You. This output can be connected to another external amplifier to listen to the sound.

When the variable volume with switch is rotated in the maximum direction even slightly from the minimum state, the volume interlock switch 7
Is switched to the fixed terminal e side, the line-out output is cut off, and no sound is output.

At this time, the reproduced signal passed through the resistor R4 is subjected to appropriate volume adjustment by the variable volume switch 6 and the reproduced signal is amplified by the headphone amplifier 2 and impedance-matched by the resistance of the variable volume switch 6 to adjust the volume. Via the fixed terminal e of the interlock switch 7,
Headphone output to stereo mini jack 3.

Further, the transistor 8 applies a voltage to the resistor R7 to attenuate the level so that noise such as switching of equipment does not occur.

In the embodiment shown in FIG. 1, the portion corresponding to the switch of the variable volume with switch, that is, the fixed terminal of the volume interlocking switch 7 is directly mechanically switched, but even if the fixed terminal is electronically switched. The same effect can be obtained.

The same effect can be obtained with a small-sized playback device even if the playback device is a tape recorder or a compact disc player.

[Effect of the invention]

As described above, according to the compact playback device of the present invention, the switch is switched in conjunction with the volume for adjusting the volume of the headphones, so the variable volume with switch is used only when the variable volume with switch is used. When the variable volume with a switch is minimized, the line-out output can be heard, and further, there is an advantage that connection to the outside requires only one stereo mini jack.

Therefore, the headphone output and the line out output are 1
This is shared by multiple minijacks.

In addition, the use of a single stereo mini jack reduces costs and is effective for miniaturization of the equipment. In addition, even if the output is for a different purpose such as a line-out or a headphone with a switch, the output is optimal for each. Since the format is switched by the volume interlocking switch, the output setting of the device and the design of the conditions are facilitated.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the small-sized reproducing device of the present invention, and FIG. 2 is a block diagram of a conventional small-sized reproducing device. 1 ... line amplifier 2 ... headphone amplifier 3 ... stereo mini jack 6 ... variable volume with switch 7 ... volume interlock switch 8 ... transistor

Claims (1)

(57) [Scope of request for utility model registration] A first amplifier for amplifying a reproduction signal; a variable volume switch with a switch for controlling a volume of a signal output from the first amplifier; and the first amplifier corresponding to a value of the variable volume with a switch. A second amplifier for amplifying the signal output of the first amplifier, and a stereo minijack for switching and outputting two or more signals such as the output of the first amplifier or the second amplifier in conjunction with the variable volume with switch. Small reproduction equipment.