JPH0145130B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic music selection device for a record player.

Conventionally, there have been devices of this type as shown in FIGS. 1 to 3. In FIG. 1, 1 is a silent groove detector, and the silent groove detector is an LED (light emitting element).
It is composed of a photodiode (light receiving element) 1a and a photodiode (light receiving element) 1b, and detects silent grooves on a moving record in conjunction with a tone arm, which will be described later. This silent groove detector 1 is connected to an arm control circuit 2. Further, 3 is an automatic music selection switch, which is used to start automating the music selection operation for conventional general use, 4 is a play stop switch, and 5 is a music selection switch, and these switches 3, 4, and 5 are Each is connected to the arm control circuit 2 described above.
The motor 6 and the arm vertical control member 7 are driven by the control signal of the arm control circuit 2, respectively.
The tone arm 8 is configured to move and move up and down. The tone arm 8 includes a cartridge 10 having a needle 9 at its tip, and is configured to move in conjunction with the silent groove detector described above. Further, numeral 11 is a record disc, and the record disc is composed of a sound groove 12 and a silent groove 13 as shown in FIG. The output of the above cartridge 10 is
Output terminal 1 via FET14 (mute element)
The FET 14 is selectively activated by the arm up/down switch 16. This arm up/down switch 16 is opened/closed by an arm up/down control member 7 as shown in FIG.

Next, the operation will be explained. After switching from manual operation to automatic song selection with the automatic song selection switch 3, when you press the song selection switch 5 to play a specific song,
A motor 6 is driven by a control signal from an arm control circuit 2, and simultaneously moves a tone arm 8 and a silent groove detector 1. When the tone arm 8 and the silent groove detector 1 begin to move in the upper space of the record 11, the silent groove detector 1 first optically detects the silent groove 13 at the beginning of the selected song. When this silent groove detection signal is applied to the arm control circuit 2, the motor 6 is stopped, and then the arm vertical control member 7 shown in FIG. 3 is lowered to lower the tone arm 8.

In this way, the needle 9 is lowered into the sound groove 12, and musical performance begins. By the way, if the silent groove 13 is wide, it is possible to accurately lower the needle 9 into the silent area, but in actual records, the silent groove 13 is narrow, and it is difficult to lower the needle 9 into this narrow range. . For this reason, various efforts have been made to align the detection position of the silent groove (for example, the point x shown in FIG. 2) with the point of descent of the needle 9.

For example, the stop position can be corrected by reducing the distance between the silent groove detector 1 and the needle 9, or by adjusting the arm feed stop position so that after detecting the silent groove, the arm feed stops after being fed the distance between the silent groove detector 1 and the needle 9. However, since the needle 9 has a vertical mechanism, there is a limit to the accuracy of the movable parts and shaft, and therefore the feed control etc. cannot be ideally performed. Even if the stylus is placed at the tip of the long arm, there will be a large error in the position of the stylus, and in some cases, the stylus may be placed in the sound groove 12 before or after the silent groove 13, causing trouble for the user. It had the disadvantage of causing discomfort. Furthermore, some records have a silent groove that is as wide as several sound grooves, but some have a width of around one, which has the disadvantage of making the conditions even worse and making them unusable. Ta. The eccentricity of the record was also a cause of this problem.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and even if there is an error between the lowering position of the stylus tip and the silent groove detection position x, the selected music can be heard from the beginning. The purpose is to provide a device that can reproduce accurately.

An embodiment of the present invention will be described below with reference to FIGS. 4 and 5. In the drawings, the same reference numerals as in FIGS. 1 to 3 indicate the same parts. In Figure 4,
The output signal of the cartridge 10 is branched, and one is outputted to a terminal 15 via a FET (mute element) 14 as in the conventional art. The other one is connected to the level detection circuit 17, the AND gate 18, and the flip-flop 19 in sequence.
is connected to the above FET14. On the other hand, one terminal 20a of the arm up/down switch 20, which is opened and closed by the same arm up/down control member 7 as shown in FIG. and the other side is directly connected to the reset R terminal of the flip-flop 19. Also, the other terminal 20b is AND
Connect to gate 18. The level detection circuit 17 described above is connected to a band amplifier 22 for expanding signal components.
It is composed of a rectifying circuit 23 which takes an AC input as a DC output, a comparator 24 which compares the output level of the silent groove 13 and the output level of the sound groove 12, and outputs zero when it is a sound groove signal, and a resistor R.

Next, the operation will be explained. Initially, flip-flop 19 is in a reset state, so FET 14 is open and no output appears at terminal 15. When the music selection switch 5 is pressed in this state, the motor 6 is driven by the control signal from the arm control circuit 2, and the tone arm 8 and silent groove detector 1 are moved. When the silent groove detector 1 optically detects the silent groove 13 at the beginning of the selected song, the detection signal is input to the arm control circuit 2, and the drive of the motor 6 is stopped. The stop position of the motor 6 can be determined by reducing the correction amount of the conventionally used arm stop position correction means (not shown), and as shown in FIG. Adjust so that the needle 9 descends to the silent groove located at or to the sound groove located in front of this silent groove.

Thereafter, the arm vertical control member 7 is lowered, and the tone arm 8 is lowered within the range indicated by the arrow B described above.

For example, if we explain the operation assuming that the needle 9 has descended to the Y point of the sound groove 12, a playback output signal (sound groove signal) other than the selected song is detected from the cartridge 10, but this playback output signal is It is blocked by the FET 14 that is connected to the terminal 15 and does not appear on the terminal 15. On the other hand, when this same reproduced output signal is input to the level detection circuit 17, it is amplified by the band amplifier 22, converted to direct current by the rectifier circuit 23, further reversed in polarity by the comparator 24, and passed through the resistor R.
It is input to the AND gate 18 (zero potential). At this time, the arm up/down switch 20 has been switched from the terminal 20a to the terminal 20b, so the positive voltage of the DC power supply E is applied to the AND gate 18 at the same time.
Since the output of AND gate 18 is zero, flip-flop 19 remains in the same reset state as it was initially. Therefore, even if the cartridge 10 detects a playback output signal, there is no input to the gate of the FET 14 and the open circuit state of the FET 14 is maintained, and unnecessary playback output signals other than the selected song do not appear at the terminal 15. Not played. In this way, while the needle 9 is in a sound groove that does not require reproduction, it is muted by the FET 14, but as the needle 9 moves further into the silent groove region, a substantially zero reproduction output signal is detected. , is amplified and rectified by the above-mentioned band amplifier 22 and rectifier circuit 23, is further compared and inverted (becomes a positive voltage) by comparator 24, and is passed through resistor R.
Input to AND gate 18. On the other hand, since a positive voltage is input to the AND gate 18 from the terminal 20b of the arm up/down switch 20, both input sides of the AND gate 18 become positive voltages, and the AND gate 18
A positive voltage is output from S of flip-flop 19.
(SET) terminal. As a result, a positive voltage is output from the output terminal Q of the flip-flop 19 and applied to the gate of the FET 14 mentioned above.
The FET 14 becomes closed, and the reproduced output signal from the cartridge 10 appears at the terminal 15. Only when the needle 9 moves to the silent groove 13 as described above can the sound of the record be played back. When the needle 9 further moves to the sound groove area of the selected song, the playback output signal (sound groove signal) of the selected song is detected by the cartridge 10 and sent to the AND gate via the level detection circuit 17. 18 (zero potential). Therefore,
Although the output of the AND gate 18 becomes zero and the set input to the flip-flop 19 disappears, the Q output of the flip-flop 19 is maintained by the memory function of the flip-flop 19, and the closed state of the FET 14 is maintained.

In the explanation so far, the needle 9 is located at the sound groove 12, for example, at Y.
We have explained the operation when the needle descends to the point 9.
To explain the operation when the needle 9 descends to a silent groove, for example, point X, the moment the needle 9 descends to point
The voltage is amplified, rectified, compared and inverted, and appears as a positive voltage at point a on the output side of the level detection circuit 17.
Immediately after switching the arm up/down switch 20, since the capacitor C of the delay circuit 21 is charged, a current flows through the transistor T, so that the point a is shot and becomes zero potential. However, this operation occurs only at the moment when the needle 9 falls to point Since a positive voltage is also applied to the AND gate 18 from
The output side of the gate 18 becomes a positive potential, and the S terminal of the flip-flop 19 also becomes a positive potential. Therefore, the Q terminal also becomes a positive potential, a positive voltage is applied to the gate of the FET 14, and an output appears at the terminal 15. By the delay circuit 21, even after the arm up/down switch 20 switches from the terminal 20a to the terminal 20b, the output side of the level detection circuit 17 is shot, the output of the AND gate 18 is set to zero, and the reset state of the flip-flop 19 is maintained. Ru. Therefore, by setting or adjusting the delay circuit 21, the needle 9 can be set in the silent groove,
For example, when descending to point X, for a certain period of time, FET
14 can be maintained in an open state to mute the reproduced output signal of the silent groove region.

As the arm stop position correction means described in the above embodiment, the distance between the silent groove detector 1 and the needle 9 may be slightly increased, or in the case of a time constant circuit, the time constant may be lowered or the pulse motor may be In the case of a rotary encoder, a linear encoder, or the like that corrects the stop position by counting the pulses associated with the stop operation and detecting the amount of movement, it is sufficient to reduce the fixed amount of the pulses.

Furthermore, in the above embodiment, C as a delay element,
Although an R element is used, if a microcomputer or the like is used in this device, a similar configuration can be made with a delay operation using microcomputer (clock) processing. Furthermore, instead of the flip-flop 19, a memory element having a similar function can be used.

Furthermore, the band amplifier 2 described in the above embodiment
Instead of 2, if you have a playback system that creates a playback equalizer and extracts its output, you can omit the band amplifier by simply removing unnecessary signals as long as the rectifier circuit and comparator of this device can be directly controlled.

As described above, the present invention includes a first means (comprised of an arm control circuit, etc.) for moving a cartridge in a substantially radial direction of a record; a second means (consisting of a silent groove detector, etc.) for moving the cartridge in the vertical direction, a third means (consisting of an arm vertical control member, etc.) for moving the cartridge in the vertical direction, and a fourth means for muting the playback signal from the cartridge. In an automatic music selection device for a record player, which includes means (consisting of FET, etc.), the playback signal from the cartridge is bypassed, and the level of the playback signal is amplified, rectified, compared and inverted to generate a binary signal. The output side of the level detection circuit is connected to the input side of the circuit, the other terminal of an arm up/down switch that is connected to a power source and opened/closed by moving the arm up and down, and the output side of the level detection circuit.
an AND gate; and a flip-flop, in which the output side of the AND gate is connected to the S terminal, one terminal of the arm up/down switch is connected to the R terminal, and the gate of the fourth means is connected to the Q terminal. It is characterized by the following. Therefore, when the cartridge is in the non-playing position, for example, when the needle 9 is at point Y in FIG.
The flip-flop maintains the reset state and mutes the playback signal by inactivating the fourth means (consisting of FET, etc.), and when the cartridge is in the playing position, for example, when the needle 9 is at point X in FIG. , and in the tone groove of the selected song, the flip-flop changes to the set state, and the muting of the reproduced signal is canceled by the operation of the fourth means (consisting of FET or the like). Therefore, according to the present invention, even if there is an error in the lowering position of the needle 9, the beginning of the song will not be played back, or conversely, the end of the song will not be played back, and the song selection can be improved. You can accurately play back a song from the beginning.

[Brief explanation of drawings]

Figures 1 to 3 show a conventional device, with Figure 1 being a block diagram, Figure 2 being a front view, and Figure 3 being a front view.
The figure is a side view. 4 and 5 show one embodiment of the present invention, with FIG. 4 being a block diagram and FIG. 5 being a front view. 1: Silent groove detector, 2: Arm control circuit, 7:
Arm vertical control member, 10: Cartridge, 1
1: Record, 13: Silent groove, 14: FET,
17: Level detection circuit, 19: Flip-flop.

Claims (1)

[Claims] 1: a first means for moving the cartridge approximately in the radial direction of the record; a second means that is moved together with the cartridge and detects a silent groove on the record; and a third means for moving the cartridge in the vertical direction. and a fourth means for muting a playback signal from the cartridge, an automatic music selection device for a record player comprising:
A level detection circuit that bypasses the playback signal from the cartridge and amplifies, rectifies, compares and inverts the level of the playback signal to generate a binary signal, and an arm up/down switch that is connected to the power supply and opens and closes by moving the arm up and down. The other terminal of the AND gate and the output side of the level detection circuit are connected to the input side, the output side of the AND gate is connected to the S terminal, and one terminal of the arm up/down switch is connected to the R terminal. An automatic music selection device for a record player, characterized in that a flip-flop is provided in which the gate of the fourth means is connected to the Q terminal.