GB2254475A - Sound reproducer and/or loudspeaker system - Google Patents

Abstract

A sound reproducing system (eg a Karaoke) comprises space detecting means (67) for detecting a space between pieces of sound information by sensing either a non-signal state or a low-level state of said reproduced signal; counting means (66) for executing either subtraction or addition with respect to a given initial count value each time said space detecting means (67) detects a space between pieces of sound information; count setting means (61) for changing the count of said counting means (66) to set a desired count value; space stop means (40) for suspending power supply to the driving motor (M) when the count of said counting means (66) coincides with the set count value; and space stop cancelling means (68) for cancelling the space stop state and shifting the system to a playback state. <IMAGE>

Description

"SOUND REPRODUCER AND/OR LOUDSPEAKER SYSTEM" The present invention relates to a sound reproducer and/or loudspeaker system and, although the invention is not so restricted, it relates more particularly to a portable recorded orchestral accompaniment system having a sound reproducer, a speaker and a microphone, which are accommodated in a casing together as one unit. The present invention further relates to a multifunctional sound reproducer suitable for a portable recorded orchestral accompaniment system, e.g. for use in "karaoke".

One type of known sound reproducer, e.g. cassette player, has a cue review function that enables recognition of the space between a pair of adjacently recorded pieces of music in the fast forward playback mode and an automatic music sensor function that stops automatically the cassette motion when the desired space between two pieces of music is reached.

Furthermore, a compact, lightweight, portable recorded orchestral accompaniment system having a sound reproducer, a speaker and a microphone, which are accommodated in a casing together as one unit, has been developed and put on sale. It is desirable to arrange that this type of recorded orchestral accompaniment system has satisfactory cue review and automatic music sensor functions for the convenience of users.

Since singers or users of a recorded orchestral accompaniment system need to select a desired one from a plurality of pieces of music recorded on a magnetic tape or the like, installation type recorded orchestral accompaniment systems are generally not desired to have merely a simple automatic music sensor function that enables sound reproduction from the start of the accessed piece of music but rather to have a multi-functional system incorporating a selective automatic music sensor function that permits the user to select a desired one from a plurality of pieces of recorded music and reproduce the selected piece from the start thereof. However, portable recorded orchestral accompaniment systems have to be small in overall size and low in both cost and power consumption.

Therefore, to realize a multifunctional system and to meet these demands have generally been considered to be contradictory to each other.

The selective automatic music sensor function that can be incorporated in known sound reproducers is designed so that when a designated piece of music is made ready for playback upon completion of a music selecting operation, a playback operation starts automatically regardless of the user's will. Therefore, if such a sound reproducer is employed to perform a recorded orchestral accompaniment in a "karaoke" performance, there is a possibility that playback of the selected piece of music may start before the user is ready to sing. Accordingly, it has heretofore been necessary for the user to constantly take note of the music selecting operation of the reproducer in order to recognize the timing of the completion of the music selecting operation.If the user is not ready to sing when the music selecting operation is completed, he or she must put the reproducer into pause mode or must conduct some other necessary operation. In particular, portable recorded orchestral accompaniment systems, for which the singer performs various operations including the music selecting operation in person, involve the problem that when the singer cancels his or her performance because the preparations therefor are incomplete, it is troublesome to carry out operations for suspending and resuming the system.

In addition, if the tape comes to an end before the completion of the music selecting operation, the travel of the tape is forcedly stopped, so that not only is unnecessary tension or stress applied to the tape and mechanical system, but also wear is accelerated of a slip mechanism, if such is provided to reduce the tape load. Moreover, electric power is wasted. Although an auto-stop mechanism that senses the end of a tape and cancels the driving state may be provided, the auto-stop mechanism that is used in low-cost sound reproducer or portable recorded orchestral accompaniment systems is designed to operate only in the playback mode and not in the fast forward or rewind mode because these systems are required to be produced at low cost.More specifically, the low-cost and light-weight autostop mechanism starts to operate in response to the operation of a mechanical tape tension sensing means that is united with a playback head of a tape deck and hence the tape tension sensing means cannot function in the fast forward or rewind mode. Means are available to cancel a fast forward or rewind operation by electrically detecting the end of a tape, but such means are unsuitable for low-cost portable systems because they involve a rise in the cost of the tape deck, an increase in the overall weight and a rise in the power consumption.

According to the present invention there is provided a sound reproducer and/or loudspeaker system comprising accommodating means for accommodating a recording medium; a driving motor for driving the recording medium; sound generating means that converts a reproduced signal from the recording medium into sound; space detecting means for detecting a space between pieces of sound information adjacently recorded on the recording medium by sensing either a non-signal state or a low-level state of said reproduced signal; counting means for executing either subtraction or addition with respect to a given initial count value each time said space detecting means detects a space between pieces of sound information adjacently recorded on the recording medium; count setting means for changing the count of said counting means to set a desired count value; space stop means for suspending power supply to the driving motor when the count of said counting means coincides with the set count value; and space stop cancelling means for cancelling the space stop state and shifting the system to a playback state.

In its preferred form, the present invention provides a portable sound reproducer and loudspeaker system having a selective automatic music sensor function suitable for the performance of recorded orchestral accompaniment with a minimal increase in the cost and a minimal rise in the power consumption and that enables such a selective automatic music sensor function to be added to a low cost, portable sound reproducer and/or loudspeaker system without any problem.

Thus in its preferred form, the present invention provides a portable sound reproducer and/or loudspeaker system having a casing body accommodating a reproducer that takes out a reproduced signal from a recording medium and a sound generating means that converts the signal into sound, a grip connected to the back of the casing body and extending substantially parallel to the casing body, and a sound input means attached to the top of either the casing body or the grip as an integral part thereof, in which the reproduced signal and a signal input to the sound input means are mixed together, amplified and output from the sound generating means, there being means for detecting a space between pieces of sound information adjacently recorded on the recording medium by sensing either a non-signal state or low-level state of the reproduced signal; counting means for executing either subtraction or addition with respect to a given initial count value each time the space detecting means detects a space between pieces of sound information adjacently recorded on the recording medium; count setting means for changing the count of the counting means to set a desired count value; space stop means for suspending power supply to a driving motor when the count of the counting means coincides with the set count value; and space stop cancelling means for cancelling the space stop state and shifting the system to a playback state.

The space stop cancelling means preferably comprises a mechanical system of the reproducer that starts in response to an external operation, which is, for example, performed by depressing a button by the user. The system preferably has an alarm sound generating means that outputs a sound generating signal to the sound generating means when a space stop state is established.

In addition, the system may be provided with a forced stop judging means as an auto-stop means which actuates the alarm sound generating means upon detection of an overload state of the driving motor not only during a space detecting operation but also during other tape transport operations.

The system may be further provided with a means for displaying the count of the counting means and a flash signal generating means that delivers a flash signal to the count display means and interrupts the sound generating signal from the alarm sound generating means during the space detecting operation.

These means provide advantageous effects, particularly when a display member of the count display means is provided on the top of the casing body at at least a position to the left or right of the position where the sound input means is installed.

By virtue of the above-described arrangement, the counting means holds either an initial set value or a count value set through the count setting means, and each time the space detecting means detects a space during a space detecting operation, i.e., a music selecting operation in the case of a recorded orchestral accompaniment system, the counting means increments or decrements the count. When the count coincides with the set value, the driving motor is suspended by the space stop means, thus completing the music selecting operation. This space stop state is maintained until the user starts the space stop cancelling means.

Accordingly, it is possible for the user to start playback of the designated piece of music at any desired time of his or her own free will. When the space stop cancelling means is realized by using a mechanical system of the reproducer, the cancellation of the stop state and operations needed to make the system ready to start playback can be effected without consuming electric power. It is therefore possible to save energy consumed in the portable sound reproducer and/or loudspeaker system and extend the lifetime of batteries incorporated therein.

If the said alarm sound generating means is provided, when a space stop state is established, the sound generating means generates an alarm sound on the basis of a sound generating signal, so that the user recognizes the completion of the music selecting operation by the alarm sound. It is therefore unnecessary for the user to watch the music selecting operation by, for example, checking the tape travel condition.

When the recording medium, for example, a magnetic tape, comes to an end during the music selecting operation, the forced stop judging means detects the forced stop state and generates a forced stop detecting signal. The alarm sound generating means is actuated on the basis of the forced stop detecting signal, and the sound generating means generates an alarm sound. The forced stop judging means functions also in the fast forward and rewind modes of tape transport operation, as a matter of course. Accordingly, if the user cuts off the power supply to the driving motor in response to the alarm sound, it is unnecessary to provide a mechanical or electrical automatic cancelling means,and it is possible to reduce the overall weight of the system, lower the costs and minimize the power consumption.

If the count display means and the flash signal generating means are provided in the above-described arrangement, during the music selecting operation the current count can be displayed in the flashing mode on the basis of a flash signal output from the flash signal generating means. It is therefore possible to inform the user that the music selecting operation is in progress, and it is also possible to generate the alarm sound as an intermittent sound by modulating the sound generating signal on the basis of the flash signal.If the display member of the count display means is provided on the top of the casing at at least a position to the left or right of the position where the sound input means is installed, the user can readily recognize the music selection display in a natural singing position (i.e. in a position in which the user brings his or her mouth close to the sound input means).

The invention is illustrated, merely by way of example, in the accompanying drawings, in which like reference numerals denote like elements, and in which: Figure 1 is a front view showing the external appearance of one embodiment of a portable recorded orchestral accompaniment system with a selective automatic music sensor circuit according to the present invention; Figure 2 is a plan view showing the external appearance of the embodiment; Figure 3 is a side view showing the external appearance of the embodiment as seen from the right-hand side of Figure 1; Figure 4 is a side view showing the external appearance of the embodiment as seen from the left-hand side of Figure 1; Figure 5 is a rear view showing the external appearance of the embodiment;; Figure 6 is a fragmentary sectional view of a left-hand half form of a casing body forming part of the embodiment, showing the structure of a microphone part and its vicinity; Figure 7 is a conceptual circuit diagram showing the arrangement of a reproduction circuit system in the embodiment; Figure 8 is a block diagram showing the arrangement of a selective automatic music sensor circuit in the embodiment; Figure 9 is a conceptual circuit diagram exemplarily showing various parts of the selective automatic music sensor circuit in the embodiment; Figure 10 is an exploded perspective view of a tape deck in the embodiment; and Figures 11 to 16 are schematic plan views of a mechanical system for illustrating lock and unlock operations accompanying the operation of each button on the tape deck.

One embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

Figures 1 to 5 show the external arrangement of one embodiment of the portable recorded orchestral accompaniment system with a selective automatic music sensor circuit according to the present invention. The system, which is suitable for use in a "karaoke" performance, is a compact unit device with a height of, for example, about 280 mm, a width of about 100 mm and a depth of about 150 mm. The device comprises a vertically elongate, substantially rectangular parallelepiped-shaped casing body 12 provided at the front, a cylindrical grip 14 (Figure 3) that is united with the casing body 12 at the back of the latter through an upper joint portion 10a and a lower joint portion 10b, and a microphone part 16 supported by a microphone support part 17 extending upwardly from the upper end of the grip 14, the microphone part 16 including a microphone 150 (Figure 7).

The casing body 12 comprises a pair of upper and lower portions, that is, a sound medium accommodating portion 120 for accommodating a tape cassette and a speaker accommodating portion 130. The left side, as seen in Figure 3, of the sound medium accommodating portion 120 is provided with a stop button 120a for suspending a magnetic tape feed operation and opening a reproduction circuit power supply switch; a fast forward button 120b for high-speed forward feed of a magnetic tape; a rewind button 120c for effecting a high-speed rewinding operation; a playback button 120d for reproducing sound signals recorded on a magnetic tape; and a start button 120e for starting playback after the completion of a music selecting operation. The front surface of the sound medium accommodating portion 120 is covered with a cover 121 that is hinged at the righthand side thereof, as seen in Figure 3.

The speaker accommodating portion 130 has a meshshaped cover 134 attached over the output surface of a speaker 73 (Figure 7) accommodated therein. The left side, as seen in Figure 3, of the speaker accommodating portion 130 is provided with an echo control rotary disc 130a for controlling echoes (reverberations) of sound taken in through the microphone 150, and a tape/microphone sound volume control rotary disc 130b for controlling the balance between the volume of sound taken in through the microphone 150 and the volume of reproduced sound. The right side, as seen in Figure 4, of the speaker accommodating portion 130 is provided with a vocal/instrumental control rotary disc 130c for controlling the balance between vocal and instrumental signals in the case of playing back a multiplex tape.

These rotary discs each have a surface area sufficiently larger than an adult's fingertip, and each disc has a hemispherical projection m and a hemispherical recess n, which are formed on the surface thereof, so that the disc can be rotated easily with one finger.

Below the vocal/instrumental control rotary disc 130c there is provided a vocal eliminating button 130d for reducing the vocal volume but increasing the instrumental volume instead in the case of playing back an ordinary tape containing vocal tunes other than multiplex tapes. A jack 130e is an input jack for an AC adapter that is employed when an external power supply is used, and a jack 130f is an input jack for connecting a cord when an external microphone is employed, for example, when a couple of users sing a duet.

The bottom of the speaker accommodating portion 130 is provided with a pair of elastic legs or projections 132a and 132b at the left and right end portions, respectively, as seen in Figure 1. The legs 132a and 132b, together with another elastic leg or projection 132c (Figure 3) attached to the bottom of the grip 14, are arranged in a triangular configuration to improve the standing stability of the apparatus, prevent its slipping, and relieve shocks thereto.

A through space 15 is defined between the grip 14 and the casing body 12. Several vertically spaced corrugations 14a are formed on the surface of the upper part of the front surface of the grip 14, which faces the through space 15, so that when the user grasps the grip 14, the balls of the user's fingers fit into the furrows of the corrugations 14a to thereby prevent slippage of the user's hand on the grip 14. In addition, a battery accommodating opening 14b is formed in the lower part of the rear side of the grip 14 so that dry batteries 14c are accommodated inside the grip 14.

The battery accommodating position thus contributes toward realizing a compact system and, at the same time, contributes to improvement in the standing stability because of a favourable weight balance with the casing body 12.

A control part 18 (Figure 4) is formed on the rear side of the grip 14 at a position which is substantially at the same height as the upper joint portion 10a and where the user can actuate a control dial and buttons with the thumb of his or her hand grasping the grip 14.

The flat surface of the control part 18 is provided with a volume dial 18a for controlling the sound volume, a vocal auxiliary button 18b adapted to output vocal sound when depressed, and a music selection button 18c (Figure 5) for designating a desired piece of music during a music selecting operation based on the automatic music sensor function, the volume dial 18a, the vocal auxiliary button 18b and the music selection button 18c being disposed in series from below in the mentioned order. It should be noted that the microphone support part 17, which has a cylindrical configuration with substantially the same diameter as that of the grip 14, extends upwardly from the upper end of the control part 18. The microphone support part 17 is formed with a bellows-shaped skin 17a (Figure 1).

The casing body 12, comprises a front form la, a right-hand half form lb and a left-hand half form lc, which are moulded out of a rigid resin material and fitted to each other, as shown in Figures 2 and 5.

Figure 6 is an enlarged view of the portions of the left-hand half form lc that define the microphone part 16 and the microphone support part 17. The left-hand half form lc has a skin portion B projecting beyond a joint portion A thereof so as to engage with the righthand half form lb that has a joint portion A projecting beyond a skin portion B thereof. The microphone part 16 has an upper microphone casing portion 160, which has a fitting hole 160a formed in the centre of the top thereof, and the microphone 150 which is inserted into the fitting hole 160a.The surface of the microphone casing portion 160 is formed with five parallel elongate holes 160b to avoid interference with vibration of the pressure-receiving surface of the microphone 150 based on sound waves and also prevent howling caused by the transfer of vibration from the body. It should be noted that reference numeral 160c denotes a tapped hole used to align and connect the right- and left-hand half forms lb and lc with each other. The microphone casing portion 160 is covered with a windshield sponge 16a made of a foamed resin material (urethane foam) with a relatively low foam density to prevent direct application of excessively high sound pressure to the microphone 150.Thus, in this embodiment, the microphone casing portion 160 is formed by moulding as an integral part of the casing, so that the number of parts to be produced is reduced. In addition, since the constituent elements can be assembled together as one unit by fitting the three casing forms la, lb and lc after all the elements, including the microphone 150, wiring, the batteries 14c, etc., have been attached to either the right-hand half form lb or the left-hand half form lc, the assembly is facilitated, and the production cost can be lowered.

A bellows-shaped skin 17a is formed on the lower portion of the microphone support part 17. The bellowsshaped skin 17a comprises a skin portion B having three U-shaped bent portions 170a, 170b and 170c, which project outwardly from a joint portion A that is reduced a little in diameter.

In contrast to the other skin portions B, which have a thickness of 2.5 mm, the bellows-shaped skin 17a is reduced in thickness to 1.5 mm to absorb and reduce vibration propagated from the body in this portion. In addition, a sound insulating wall 171 is formed above the bellows-shaped skin 17a to intercept sound waves propagated inside the microphone support part 17. If necessary, a sound absorbing member may be attached to each of the upper and lower surfaces of the sound insulating wall 171. Thus, the amount of sound wave and vibration fed back to the microphone 150 is reduced by the above-described structure of the microphone support part 17, thereby preventing howling.

In this embodiment, the casing body 12 is convexly bent forwardly with respect to the direction in which the grip 14 extends, so that the front surface of the sound medium accommodating portion 120 faces upwardly, while the front surface of the speaker accommodating portion 130 faces downwardly. More specifically, as shown in Figure 3, the front surface of the sound medium accommodating portion 120 faces upwardly at about 15 degrees to the direction of extension of the grip 14, while the front surface of the speaker accommodating portion 130, that is, the output surface of the speaker, faces downwardly at about 20 degrees to the direction of extension of the grip 14. The angle of the front surface of the speaker accommodating portion 130 to the grip 14 is set so that the output direction of the speaker will not be upward when the grip 14 is grasped by the user when singing.The angle of the front surface of the speaker accommodating portion 130 is effective for preventing howling because the output direction of the speaker deviates substantially from the centre direction of the directivity of the microphone 150. On the other hand, the angle of the sound medium accommodating portion 120 is effective for eliminating forward projection of the apparatus and reducing the overall size. In addition, since the casing body 12 is curved as a whole, it is possible to ensure a sufficiently large through space 15 for the user to grasp the grip 14 even when the distance between the upper end of the sound medium accommodating portion 120 and the grip 14 is reduced in order to meet the demand for a reduction in the overall size to realize a compact system.Moreover, it is possible to minimize the height of the casing body 12, that is, the overall height of the apparatus, which is determined to be a given numerical value by the dimensions of a sound medium used and the diameter of the speaker.

The direction of extension of the grip 14 is set so that the apparatus is about 5 degrees inclined rearwardly from the vertical direction when it is placed in a standing position. By so doing, the centre of gravity is shifted rearwardly to maintain the weight balance with the casing body 12, which has a relatively heavy weight, thereby further improving the standing stability.

In this embodiment, a 7-segment LED display 140 is attached to the top of the casing body 12 at a position to the left, as seen in Figure 3, of the microphone part 16 to display the condition of music selection effected by a selective automatic music sensor circuit (described later). The LED display 140 is accommodated in a space that is defined between a cut portion of the front form la and a cut portion of the left-hand half form lc. Since no bore is provided in the casing but a space defined between the two cut portions is used to accommodate the LED display 140, it is only necessary to prepare a pair of male and female mould members for moulding the casing from a resin material, and no slide mould is needed. Accordingly, the production cost of the moulding tools can be reduced.

Since the LED display 140 is provided at a forward position closer to the microphone part 16, the user can view the display 140 in a natural singing position.

Further, since the position of the LED display 140 is set to the left of the microphone part 16, even when the user is not in a singing position (for example, when the user holds the apparatus in such a way that the microphone part 16 is moved away from the user's mouth and the direction of extension of the grip 14 approaches the vertical), the display 140 can be readily viewed by a right-handed user who is grasping the grip 14 with his or her right hand. It should be noted that the position of the LED display 140 may be set to the right of the microphone part 16 (this is better for left-handed persons).In any case, by disposing the LED display 140 at a position to either the left or right of the microphone part 16, it is possible for the user to confirm the condition of music selection easily without assuming an unnatural position, for example, looking down at the LED display 140 from above the apparatus, because the display 140 is not hidden by the microphone part 16 or the microphone support part 17. It should be noted that the LED display 140 may be replaced with another display device, for example, a liquid crystal display (LCD).

Figure 7 shows a basic circuit configuration of a reproduction circuit 70 employed in a tape deck that is incorporated in the rear end portion of the sound medium accommodating part 120.

The reproduction circuit 70 has a vocal reproduction magnetic head 70a and an instrumental reproduction magnetic head 70b for playing back a multiplex tape. Very weak vocal and instrumental signals reproduced by these heads 70a and 70b are amplified in respective preamplifiers 71a and 71b, and the amplified signals are mixed together through resistors Ral, Ra2 and Rbl, Rb2. The resultant signal is passed through a variable resistor Rv0 controlled with the above-described volume dial 18a and then amplified in an output amplifier 72 before being delivered to a speaker 73. In this circuit, a vocal auxiliary switch S5 is normally closed, and it is opened when the vocal auxiliary button 18b (Figure 3) is depressed to supply the reproduced vocal signal to the speaker 73.A variable resistor Rp is provided to determine an output ratio of the reproduced vocal and instrumental signals when the vocal auxiliary switch S5 is closed. Normally, the variable resistor Rp is controlled with the vocal/instrumental control rotary disc 130c (Figure 4) so that the reproduced vocal signal is very weak relative to the reproduced instrumental signal. When the vocal auxiliary switch S5 is opened, the ground potential that has been supplied through each divided resistance of the variable resistor Rp is cut off, disabling the variable resistor Rb. As a result, the reproduced vocal signal is outputted with almost the same level as that of the reproduced instrumental signal. Accordingly, if the singer forgets the words, he or she depresses the vocal auxiliary button 18b, whereby the reproduced vocal signal can be supplied to the speaker 73 in place of the singer's voice.

It should be noted that the vocal signal input through the condenser microphone 150 attached to the microphone part 16 is amplified in a preamplifier 81, passed through a variable resistor Rvl and a resistor Rm, mixed with the reproduced vocal and instrumental signals in the output part of the reproduction circuit 70, and then outputted together from the speaker 73.

In the meantime, the reproduced vocal and instrumental signals amplified in the preamplifiers 71a and 71b are mixed together through respective resistors Ra3 and Rb3 and supplied through a capacitor C to a space detecting circuit 67 that constitutes a part of the selective automatic music sensor circuit to detect a space between a pair of adjacently recorded pieces of music. The selective automatic music sensor circuit in this embodiment will be explained below with reference to the block diagram of Figure 8.

The selective automatic music sensor circuit comprises a switch judging circuit 10, a low-frequency oscillating circuit 20, a high frequency oscillating circuit 30, a forced stop judging circuit 40, a motor driving circuit 50, an auto-set circuit 61, a logical circuit 62, an LED driving circuit 63, an LED display 64, a set pulse generating circuit 65, an up-down counter 66, a space detecting circuit 67, and a space stop circuit 68.

The switch judging circuit 10 delivers a music selection mode signal a of H or L level in accordance with the on-off position of a leaf switch S1 that opens and closes in response to the playback button 120d (PLAY), that of a leaf switch S2 that operates in response to the fast forward button 120b (FF) and that of a leaf switch S3 that operates in response to the rewind button 120c (REW).

The operation of the switch judging circuit 10 is shown in Table 1 below.

TABLE 1

SI S1 (PLAY) | S2 (FF) | S3 (REW) Music selection mode signal ON OFF OFF L ON ON OFF t ON OFF ON H OFF ON OFF L OFF OFF ON L The low-frequency oscillating circuit 20 delivers a flash signal f of frequency 2.5 HZ to both the highfrequency oscillating circuit 30 and the LED display 64 when the music selection mode signal a is at H level or when a forced stop signal e is supplied thereto.The high-frequency oscillating circuit 30 delivers an alarm signal g of frequency 1.67 kHz to the speaker 73 when it is supplied with a stop detecting signal d from the motor driving circuit 50 or a forced stop signal e from the forced stop judging circuit 40. The forced stop judging circuit 40 detects from the motor driving circuit 50 a state where an electronic governor motor 51 is forcedly stopped by force applied thereto because of a tape end or by other external force, and delivers a forced stop signal e to the low- and high-frequency oscillating circuits 20 and 30. The motor driving circuit 50 is brought into a driving state when the power supply is turned on, and stops the feed of current to the electronic governor motor 51 in response to a space stop signal b from the space stop circuit 68.The auto-set circuit 61 initializes the logical circuit 62 and the up-down counter 66 when the music selection mode signal a shifts to H level, and sets the count of the up-down counter 66 to 1. The logical circuit 62 converts the output signal from the up-down counter 66, corresponding to the count thereof, and delivers the converted signal to the LED driving circuit 63. The LED driving circuit 63 delivers a display signal to the LED display 64 to instruct the latter to display the count of the up-down counter 66. The set pulse generating circuit 65 delivers a select music setting signal to the up-down counter 66 each time the music selection button S4 is depressed.The up-down counter 66 increments the count by one and stores the current count each time it receives a select music setting signal from the set pulse generating circuit 65, and the up-down counter 66 decrements the count by one and stores the current count each time it receives a space detecting signal from the space detecting circuit 67. The space stop circuit 68 delivers a space stop signal b to the motor driving circuit 50 when the music selection mode signal a is at H level and, at the same time,the count of the up-down counter 66 is zero.

The operation of the selective automatic music sensor circuit will be explained below on the basis of the circuit configuration described above.

First, when the playback button 120d alone is depressed, the whole circuit is supplied with electric power, so that the motor driving circuit 50 rotates the electronic governor motor 51 for driving the reels of a compact tape cassette, and the reproduced signal from the reproduction circuit 70 playing back the tape cassette is delivered to the speaker 73 to output reproduced sound. Since in this state the space detecting circuit 67 is also supplied with power, it detects the input condition of the reproduced signal, and when a non-signal state or a low-level state continues for 0.15 sec, the space detecting circuit 67 outputs a space detecting signal to the up-down counter 66 to decrement the count by one.

In this state, only the leaf switch S1 that operates in response to the playback button 120d is in an "on" state, so that the music selection mode signal a outputted from the switch judging circuit 10 is maintained at L level.

If in this state, either the fast forward button 120b or the rewind button 120c is depressed in addition to the playback button 120d, the tape starts fast forward or rewind travel on the basis of the mechanical system. Since at this time either the leaf switch S2 or S3 turns on in addition to the leaf switch S1, the music selection mode signal a from the switch judging circuit 10 shifts to H level, causing the system to start a music selecting operation.

At this time, the auto-set circuit 61, receiving the music selection mode signal a of high level, sets the logical circuit 62 and the up-down counter 66 to their initial states, so that the count "1" is set on the up-down counter 66 as its initial value. The count "1" is introduced into the logical circuit 62 and displayed on the 7-segment LED display 64 by the LED driving circuit 63. The arrangement is such that in response to depression of the music selection button S4 the set pulse generating circuit 65 delivers a select music setting signal to the up-down counter 66, thereby incrementing the count of the up-down counter 66 by one at a time, and thus permitting the user to set any desired value corresponding to a song which he or she desires to sing.

The music selection mode signal a is also inputted to the low-frequency oscillating circuit 20 to deliver the flash output f to the LED display 64 to display the count in the flashing mode.

During the music selecting operation, the count of the up-down counter 66 is decremented by one each time a space between a pair of adjacently recorded pieces of music is detected by the space detecting circuit 67, and when the count reaches zero, the space stop circuit 68, into which the music selection mode signal a of H level has been introduced, delivers a space stop signal b to the motor driving circuit 50. At this time, the motor driving circuit 50 stops the motor 51 and delivers a stop detecting signal d to forcibly raise the input potential of the high-frequency oscillating circuit 30, causing it to oscillate. The output g from the highfrequency oscillating circuit 30 is modulated by the flash signal f from the low-frequency oscillating circuit 20 and then delivered to the speaker 73, thus outputting intermittent sound from the speaker 73.

During the generation of the intermittent sound, the travel of the tape is suspended with the detected space set at the playback head position. If the start button 120e is depressed in this state, the fast forward button FF or the rewind button REW, which has been in a depressed position, is released and the system is restored to a normal playback state to start reproduction of the designated piece of music.

The following is a description of an operation that takes place when the travel of the tape is forcedly stopped because the tape comes to an end or owing to other mechanical interference before the music selecting operation is completed in the above-described music selection mode. In such a case, a large load stress is applied to the motor 51, resulting in an increase in the motor driving current. The forced stop judging circuit 40 detects the increase in the driving current and outputs a forced stop signal e, which raises the input potentials of both the low- and high-frequency oscillating circuits 20 and 30, thus causing the speaker 73 to generate intermittent sound.

Figure 9 is a conceptual view exemplarily showing the arrangements of the principal circuits shown in Figure 8, that is, the switch judging circuit 10, the low-frequency oscillating circuit 20, the high-frequency oscillating circuit 30, the motor stop judging circuit 40 and the motor driving circuit 50.

Between a power supply voltage of 6 V and the ground potential, a parallel circuit of the leaf switches S2 and S3 and the leaf switch S1 are connected in series, so that the music selection mode signal a shifts to H level only when the leaf switch S1 and either the leaf switch S2 or S3 are closed. The music selection switch S4 is connected to these switches and arranged to supply the ground potential to the set pulse generating circuit 65 to generate a select music setting signal when only the leaf switch S1 or only the leaf switch S2 or S3 is closed. When the leaf switch S1 and either the leaf switch S2 or S3 are closed, the ground side potential of the music selection switch S4 rises, so that no select music setting signal can be generated any longer.

When the music selection mode signal a shifts to H level, an H-level potential is supplied to the auto-set circuit 61 to initialize the up-down counter 66, as stated above. In addition, the input potential of the low-frequency oscillating circuit 20 rises, so that a flash signal f of frequency 2.5 Hz is generated to instruct the LED display 64 to flash.

Upon completion of selection of music in this state, an H-level space stop signal b is delivered from a driver circuit 68a, and an L-level signal is applied to the base of a transistor V1 through a NAND gate G3, thus cutting off the transistor V1. In consequence, the gate potential of a transistor V3 rises, so that the transistor V3 is also cut off, and the motor 51 stops.

In this state, a stop detecting signal d that is transmitted through a resistor R1 and a diode D3 is at high potential, so that the high-frequency oscillating circuit 30 oscillates at about 1.67 kHz. At this time, the flash signal f from the low-frequency oscillating circuit 20 is being inputted to the high-frequency oscillating circuit 30 through a diode. Therefore, as the potential of the flash signal f lowers, the input potential of the high-frequency oscillating circuit 30 also lowers to stop the oscillation. Thus, the oscillating condition of the high-frequency oscillating circuit 30 is interrupted exactly at the period of the flash signal f. Accordingly, the alarm signal g outputted from the high-frequency oscillating circuit 30 is modulated at a period of 2.5 Hz, and the speaker 73 generates intermittent sound.

When the motor 51 is forcedly stopped because the tape comes to an end during the music selecting operation, an overload is applied to the motor 51, causing an increase in the motor driving current. In this embodiment, the tape take-up torque during the fast forward or rewind operation is 2 to 6 gcm, and the motor driving current at that time is about 100 mA. In contrast, when an overload is applied to the motor 51 because the travel of tape is forcedly stopped, the motor driving current increases rapidly to about 400 to 500 mA.

Accordingly, the voltage drop across a resistor R2, which is set to 1.8Q, exceeds 0.6 V, so that a transistor V2 turns on. As a result, the forced stop signal e rises to a high potential, causing increases in the input potentials of both the low- and high-frequency oscillating circuits 20 and 30 through diodes D4 and D3.

Accordingly, in this case also, intermittent sound is outputted from the speaker 73 in the same way as in the case of the completion of the music selecting operation described above. In the music selection mode, the input potential of the low-frequency oscillating circuit 20 has already been raised to high level by the music selection mode signal a; therefore, it is not necessary to supply a high potential thereto through the diode D4.

However, by doing so, intermittent sound is generated also in the fast forward mode or the rewind mode, in which the music selection mode signal a is at L level.

With the selective automatic music sensor circuit, when the end of the designated piece of music is detected, a space stop state is established and this state is maintained, and at the same time, the user is informed of the completion of the music selecting operation with intermittent sound. Thereafter, when the user actuates the start button 120e on the basis of the mechanical system (described later), a playback operation is started. Accordingly, the user can recognize the completion of the music selection precisely by the sense of hearing. Moreover, since playback is not started until the start button 120e (described later) is depressed, the user need not intentionally consider the progress of the music selecting operation, and he or she can start playback at any desired time.

In addition, since the circuit configuration is such that when the tape comes to an end during the music selecting operation in the fast forward or rewind mode, the user is informed of this condition with intermittent sound, no mechanical or electrical tape travel cancelling means is needed, and it is possible to reduce the overall size of the reproducer or lower the power consumption while reducing the load applied to the tape and preventing wear of a slip mechanism provided on the tape reel. The LED display 64 displays the number of pieces of music present before the designated one, and the numerical figure flashes during the music selecting operation. Therefore, the user can recognize clearly that the music selecting operation is in progress by the sense of sight, too.Since the low-frequency oscillating circuit 20 for the flashing display also functions as a modulating means for forming intermittent sound from the alarm sound output from the highfrequency oscillating circuit 30, the circuit configuration can be simplified. Thus, the arrangement, together with the above described circuit configuration, enables the cost of the reproducer to be lowered.

Finally, the mechanical system of a tape deck that relates to the selective automatic music sensor circuit will be explained. Figure 10 is an exploded perspective view of a tape deck in this embodiment, and Figures 11 to 16 are schematic plan views for illustrating lock and unlock operations accompanying the operation of each of the buttons on the tape deck.

The tape deck 400 has the stop button 120a, the fast forward button 120b, the rewind button 120c, the playback button 120d and the start button 120e, which are secured to respective engagement members 440, 433, 419, 405 and 428.

Among the buttons, the fast forward button 120b, the rewind button 120c and the playback button 120d have projections S, T and R which are provided on the respective back surfaces by an integral moulding process so that the projections S, T and R press the respective contacts of the leaf switches S2, S3 and S1, which are attached to the bottom of the front end portion of a board 401 made of a resin material. In general, switches whose contacts are closed in an "off" state involve instability factors, for example, a maloperation that may be invited by separation of the contacts due to the vibration of the reproducere or the like.In contrast, the leaf switches S1, S2 and S3 are arranged such that the respective terminals are open when the playback button 120d, the fast forward button 120b and the rewind button 120c are in an "off" state, thereby eliminating instability factors attributable to undesirable separation of the contacts.

The tape deck 400 is formed by mounting necessary constituent elements on the obverse and reverse sides of the resin board 401, as shown in Figure 10. On the obverse side of the resin board 401 are provided reel shafts 402 projecting to fit into reel holes, respectively, of a tape cassette. In addition, a play lever 404 is mounted on the obverse side of the resin board 401 in such a manner as to be slidable in directions Y+ and Y- on the board 401, the play lever 404 being equipped with a head assembly 403 incorporating the vocal reproduction magnetic head 70a and the instrumental reproduction magnetic head 70b.

The play lever 404 has an engagement member 405 for contact by the reverse side of the playback button 120d.

In addition, a coil spring 406 is stretched between the play lever 404 and the resin board 401 to bias the play lever 404 in the direction Y+ by the resilient force therefrom when the play lever 404 is moved in the direction Y-.

On the reverse side of the resin board 401 are mounted a lower slide plate 407 and an upper slide plate 408, as shown in Figure 11. The lower slide plate 407 is slidable in directions X+ and X-. When moved in the direction X+, the lower slide plate 407 is biased in the direction X- by resilient force from a torsion spring 407a. The upper slide plate 408 is slidable in the directions X+ and X- over the lower slide plate 407.

When moved in the direction X+, the upper slide plate 408 is biased in the direction X- by resilient force from a coil spring 408a.

The operation of the mechanical system that accompanies the operation of the selective automatic music sensor circuit will be explained below. First, when the playback button 120d is depressed, the contacts of the leaf switch S1, shown in Figure 10, are closed, and the play lever 404 (shown by the one-dot chain line in Figure 12) is pushed to move in the direction Y-.

The play lever 404 has a projection 409 extending to the reverse side of the resin board 401 through a throughhole provided therein. The projection 409 pushes a slide plate 410 (shown by the two-dot chain line in Figure 12) in the direction Y-, so that a projection 411 of the slide plate 410 closes a leaf switch 412 that functions as a power switch. When the leaf switch 412 is closed, the power supply voltage is supplied to the motor and the circuit system. At the same time, another projection 413 of the play lever 404 that also extends through the resin board 401 presses a slant surface of a pawl-like portion 414 of the lower slide plate 407, causing the lower slide plate 407 to move in the direction X+ together with the upper slide plate 408 against the resilient force from the torsion spring 407a.As a result, the projection 413 engages with the pawl-like portion 414 to lock the play lever 404.

If the rewind button 120c, shown in Figure 10, is depressed in this playback mode, the contacts of the leaf switch S3 are closed to start a music selecting operation. In addition, a rewind lever 415 that is engageable with the rewind button 120c is pushed to move in the direction Y- against the resilient force from a torsion spring 416, as shown in Figure 13. In consequence, a slant surface of a pawl-like portion 417 of the rewind lever 415 pushes a projection 418 of the upper slide plate 408, causing the upper slide plate 408 to move in the direction X+ relative to the lower slide plate 407 against the resilient force from the coil spring 408a. As a result, the pawl-like portion 417 and the projection 418 engage with each other to lock the rewind lever 415.

After the music selecting operation is started in this way, the motor drive is stopped at the space immediately before the designated piece of music on the basis of the operation of the above-described circuit system.

According to a known space stop method, when a space stop signal is detected, this signal is converted into a mechanical driving force through an electromagnetic plunger or the like, and a release lever (described later) or the like is moved with this driving force to unlock the play lever 404 and the rewind lever 415, thereby stopping the motor. However, when the electromagnetic plunger is started, a current of several amperes is generated instantaneously, so that a large amount of electrical power is consumed.

There is another known method in which the rewind state is locked electrically. This method, however, also involves the problem that the power consumption is high.

In contrast to these known methods, this embodiment employs a method in which the drive of the motor is stopped upon the generation of a space stop signal with the rewind state being locked mechanically, and the user is informed of the stopping of the motor drive. It is therefore possible to save the power otherwise consumed to cancel the rewind state. In the portable sound reproducer, that is, the portable recorded orchestral accompaniment system, of this embodiment, the battery power can be used only for the speaker output and the playback operation. Therefore, even lightweight batteries can be used for a relatively long time without replacement.

When an alarm sound is outputted upon establishment of a space stop state, if the singer depresses the start button 120e, shown in Figure 10, a start lever 420, shown in Figure 13, is pushed in the direction Y- against the resilient force from the torsion spring 407a, so that a projection 421 of the start lever 420 pushes a slant portion 422 of an opening in the upper slide plate 408, causing the upper slide plate 408 to move in the direction X+. In consequence, the projection 418 of the upper slide plate 408 disengages from the pawl-like portion 417 of the rewind lever 415. As a result, the rewind lever 415 is unlocked and returned in the direction Y+ by the resilient force from the torsion spring 416, as shown in Figure 14. As the rewind button 120c returns in the direction Y+, the leaf switch S3 also returns to the open state.

When the leaf switch S3 opens, the music selection mode signal a returns to L level, so that the space stop state of the motor driving circuit 50 is cancelled, and the motor starts rotating to return to the playback mode. Thus, since playback is started simply by depressing the start button 120e in the space stop state, operability is very good and the user can start singing at any desired time after his or her preparations are completed.

When the fast forward button 120b, shown in Figure 10, is depressed in the playback mode also, an operation similar to that in the case where the rewind button 120c is depressed (described above) takes place. That is, the leaf switch S2 is closed to start a music selecting operation. In addition, as shown in Figure 16, the fast forward lever 430 is pushed to move in the direction Yagainst the torsion spring 416, so that a slant portion of a pawl-like portion 431 of the fast forward lever 430 pushes a projection 432 of the upper slide plate 408 in the direction X+. As a result, the fast forward lever 430 is locked by the engagement between the pawl-like portion 431 and the projection 432.

When the start button 120e is depressed after the system has shifted to the space stop state, the start lever 420 is pushed to move in the direction Y-, as shown in Figure 15, so that the projection 421 of the start lever 420 pushes the opening slant portion 422, causing the upper slide plate 408 to move in the direction X+. As a result, the projection 432 disengages from the pawl-like portion 431, thus unlocking the fast forward lever 430.

In the embodiment described above, the portable sound reproducer and/or loudspeaker system is provided with a selective automatic music sensor circuit and further has a space stop means that temporarily suspends the power supply to the driving motor immediately before the designated piece of music, and a space stop cancelling means that cancels the space stop state and starts a playback operation. Accordingly, the user can start singing at any desired time after his or her preparations are completed, and the necessity for the user to have regard for the progress of the music selecting operation is lessened. If the space stop cancelling means is realized by using the mechanical system of the reproducer, no electrical drive is needed for cancellation of the space stop state and for the mechanical system.Accordingly, it is possible to add the selective automatic music sensor circuit function without involving an increase in the power consumption of the system.

If the alarm sound generating means is provided, when a space stop state is established, the sound generating means generates an alarm sound on the basis of a sound generating signal, and the user recognizes the completion of the music selecting operation by the alarm sound. It is therefore unnecessary for the user to watch the music selecting operation by, for example, checking the tape travel condition.

When the travel of a recording medium, e.g. a magnetic tape, is forcedly stopped during the music selecting operation because the tape comes to an end or from some other cause, not to mention during a highspeed operation of the tape, the forced stop judging means detects the forced stop and generates a forced stop detecting signal. The alarm sound generating means is actuated on the basis of the forced stop detecting signal, and the sound generating means generates an alarm sound. Accordingly, if the user cancels the drive state of the reproducer in response to the alarm sound, it is possible to prevent application of load on the tape and wear of the mechanical system and to avoid waste of electric power, and there is no need for a mechanical or electrical automatic cancelling means.

Thus, it is possible to reduce the overall weight of the system, lower the cost and minimize the power consumption.

If the count display means and the flash signal generating means are provided in the above-described arrangement, during a music selecting operation a flash signal output from the flash signal generating means is delivered to the count display means to display the count in the flashing mode, and the sound generating signal is interrupted by the flash signal, thereby enabling the alarm sound to be generated as intermittent sound. In other words, if the flash signal generating means is adapted to fulfil both the display flashing function and the sound generating signal modulating function, it is possible to inform the user that a music selecting operation is in progress by the flashing display and also intensify the attention calling capability of the alarm sound while simplifying the circuit configuration and lowering the power consumption.

When employed in a portable sound reproducer and/or loudspeaker system, the selective automatic music sensor circuit enables a multiplicity of functions to be added to the system while meeting the demands for the system to be reduced in power consumption, overall weight and costs. In this case, if a display member for music selection is provided on the top of the casing body at a position to either the left or right of the position where the sound input means is installed, the user can readily recognize the music selection display in a natural singing position (i.e. in a position in which the user brings his or her mouth close to the sound input means).

Although the present invention has been described through specific terms, it should be noted that the described embodiment is not necessarily exclusive and that various changes and modifications may be imparted thereto without departing from the scope of the invention which is limited solely by the appended claims.

Claims (14)

1. A sound reproducer and/or loudspeaker system comprising accommodation means for accommodating a recording medium; a driving motor for driving the recording medium; sound generating means that converts a reproduced signal from the recording medium into sound; space detecting means for detecting a space between pieces of sound information adjacently recorded on the recording medium by sensing either a non-signal state or a low-level state of said reproduced signal; counting means for executing either subtraction or addition with respect to a given initial count value each time said space detecting means detects a space between pieces of sound information adjacently recorded on the recording medium; count setting means for changing the count of said counting means to set a desired count value; space stop means for suspending power supply to the driving motor when the count or said counting means coincides with the set count value; and space stop cancelling means for cancelling the space stop state and shifting the system to a playback state.

2. A sound reproducer and/or loudspeaker system according to claim 1, wherein said space stop cancelling means is a mechanical system of said reproducer that starts in response to an external operation.

3. A sound reproducer and/or loudspeaker system according to claim 1 or 2, further comprising alarm sound generating means for outputting a sound generating signal to said sound generating means on the basis of said space stop state.

4. A sound reproducer and/or loudspeaker system according to claim 3, further comprising forced stop judging means for actuating said alarm sound generating means upon detection of an overload state of said driving motor.

5. A sound reproducer and/or loudspeaker system according to any preceding claim, further comprising count display means for displaying the count of said counting means.

6. A sound reproducer and/or loudspeaker system according to claim 5, further comprising flash signal generating means for delivering a flash signal to said count display means and interrupting the sound generating signal from said alarm sound generating means during the space detecting operation of said space detecting means.

7. A sound reproducer and/or loudspeaker system as claimed in any preceding claim, in which there is a sound input means and means for mixing together the said reproduced signal and a signal from said sound input means.

8. A sound reproducer and/or loudspeaker system as claimed in any preceding claim, in which the system is a portable system having a casing body within which are mounted the said accommodation means, the driving motor, the sound generating means, the space detecting means, the counting means, the count setting means, the space stop means and the space stop cancelling means.

9. A sound reproducer and/or loudspeaker as claimed in claim 8, in which the casing body is provided at its back with a grip which extends substantially parallel to the casing body.

10. A sound reproducer and/or loudspeaker as claimed in claim 8 or 9 when dependent upon claim 7 in which the sound input means is attached to the top of either said casing body or said grip.

11. A sound reproducer and/or loudspeaker system as claimed in any of claims 8-10 when dependent upon claim 5, wherein said count display means has a display member provided on the top of said casing body at at least a position to the left or right of the said input means.

12. A sound reproducer and/or loudspeaker system substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

13. Any novel integer or step, or combination of integers or steps, hereinbefore described and/or as shown in the accompanying drawings, irrespective of whether the present claim is within the scope of, or relates to the same or a different invention from that of, the preceding claims.

14. A portable sound reproducer and/or loudspeaker system having a casing body accommodating a reproducer that takes out a reproduced signal from a recording medium and a sound generating means that converts said signal into sound, a grip connected to said casing body and extending substantially parallel to said casing body, and a sound input means attached to the top of either said casing body or said grip as an integral part thereof, in which said reproduced signal and a signal input to said sound input means are mixed together, amplified and output from said sound generating means, wherein the improvement comprises: means for detecting a space between a pair of pieces of sound information adjacently recorded on the recording medium by sensing either a non-signal state or low-level state of said reproduced signal; counting means for executing either subtraction or addition with respect to a given initial count value each time said space detecting means detects a space between a pair of pieces of sound information adjacently recorded on the recording medium; count setting means for changing the count of said counting means to set a desired count value; space stop means for suspending power supply to a driving motor when the count of said counting means coincides with the set count value; and space stop cancelling means for cancelling the space stop state and shifting the system to a playback state.