JPH057787Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a receiving device installed in an automobile or the like.

BACKGROUND ART Conventionally, an extendable antenna means has been provided on the body of an automobile, and a signal from the antenna means is applied to a radio receiver to receive radio broadcasts.

Problems to be Solved by the Invention In such prior art, the radio receiver is energized even during the expansion and contraction movement of the antenna, and therefore the antenna element and the synthetic resin housing housing it are Due to static electricity generated by the contact between the tubes, various noises were audible from the radio receiver's speakers.

An object of the present invention is to provide a receiving device for an automobile that prevents noise from the receiving means from becoming acoustic when the antenna means is driven to extend or contract.

Means for Solving the Problems The present invention has an extendable and retractable antenna means mounted on an automobile and two input terminals, and corresponds to the direction in which a ground potential and a high or low level potential are applied to each terminal. a drive means that is capable of rotating in the forward and reverse directions and drives the antenna means to expand and contract; a cutoff means for cutting off power supply to the drive means; a reception means for receiving a signal from the antenna means; detecting the application of a high or low level potential to both terminals of the drive means; When the high or low level potential is applied, the receiving means is disabled and a mute signal is applied to the receiving means via a lead wire to prevent the receiving means from making the received signal audible. A receiver for a vehicle is characterized in that it includes means.

Effect According to the present invention, the antenna means mounted on the rear trunk of a car or the like is configured to be expandable and retractable. A drive means realized by a DC motor or the like is provided in association with the antenna means. The driving means has two input terminals and can rotate in both forward and reverse directions depending on the direction in which a ground potential and a high or low level potential are applied to each terminal.
For example, if one terminal is set to ground potential and the other terminal is set to high level potential,
rotating in a positive direction to extend the antenna means;
On the other hand, when one terminal is set to a high level potential and the other terminal is set to a ground potential, the antenna means rotates in the opposite direction and the antenna means is contracted.

Further, a blocking means is provided adjacent to the antenna means. This cutoff means is realized by a limit switch or the like, and is interposed between the power source and the input terminal of the drive means. This cutoff means cuts off the power supply to the drive means when it detects that the antenna means has been extended to the upper end when the antenna means is extended, and cuts off the power supply to the drive means when it detects that the antenna means has been reduced to the lower end when it is contracted. Cut off.

Therefore, it is possible to accurately detect that the antenna means has actually expanded or contracted by a predetermined amount, and the power supply is immediately cut off upon detection. Therefore, even when the antenna means does not extend and retract smoothly when the voltage of the battery, which is the power source, is low or low or in cold weather, the antenna means must be reliably extended and contracted until it is extended or contracted. I can do it. Further, when the battery voltage is high, the power supply is cut off immediately after the expansion/contraction operation is completed, so that the driving means is not overloaded, thereby reliably preventing damage to the driving means.

A received signal from the antenna means is input to a receiving means such as a radio receiver via a coaxial cable or the like. The receiving means can demodulate the received signal and make it audible using a speaker or the like.

The potential of the input terminals of the driving means is detected by blocking means, and when the high or low level potential is applied to these terminals, the blocking means mututes to the receiving means via a lead wire. give a signal. When the mute signal is input, the receiving means suppresses the level of the acoustic signal obtained by demodulating the received signal, thereby preventing it from becoming audible.

Therefore, during the expansion and contraction of the antenna means, the receiving means is disabled and the reception signal is prevented from becoming audible, thereby making noise generated by the expansion and contraction of the antenna means audible. You can comfortably receive radio broadcasts, etc.

Further, the blocking means only detects the high or low level potential, and therefore, the high or low level potential is connected to a single lead wire as a mute signal output in response to the detection result. can be applied to the receiving means via the receiver. That is, the ground potential is the same as that of the vehicle body, and only one lead wire can be routed between the blocking means and the receiving means. This makes it possible to comfortably receive radio broadcasts as described above with the minimum necessary lead wires.

Embodiment FIG. 1 is a block diagram showing the electrical configuration of a receiving device 1 according to an embodiment of the present invention, and FIG. 2 is a sectional view of the vicinity of the antenna 2. The antenna element 4 of the antenna 2 attached to the car body 3 of the automobile is
It is driven to expand and contract by the motor 5 and protrudes outward from the vehicle body 3 or is housed within the vehicle body 3. The antenna element 4 is formed into a telescopic shape of a plurality of concentric cylinders having slightly different outer diameters, and is housed in a contracted state in a synthetic resin housing tube 6. The expansion and contraction of the antenna element 4 is performed via a drive member 7 whose one end is fixed to the base end of the cylinder with the smallest diameter constituting the element 4, that is, the cylinder that is placed at the tip most when it is expanded. It is done. The driving member 7 is a longitudinal body that is flexible and does not expand or contract in the longitudinal direction, and is inserted through the plurality of cylinders that constitute the antenna element 4, and has a large number of teeth 7a in the longitudinal direction. is formed,
A take-up reel 8 fixed to the output shaft of the motor 5 meshes with the teeth 7a to take up or unwind the antenna element 4 to extend and retract it. A detection switch 9 for detecting the expansion and contraction movement of the antenna element 4 is provided near the base end of the storage tube 6 .

The radio waves received by the antenna element 4 are applied to a front end circuit 11 and tuned, detected by a detection circuit 12, demodulated into a radio broadcast acoustic signal, and applied to a volume adjustment circuit 13. The sound signal whose volume has been adjusted by the volume adjustment circuit 13 passes through a resistor 15, is amplified by an amplifier circuit 17 from a line 16, and is turned into sound by a speaker 18. In this way, the radio broadcast can be received while the antenna element 4 is maintained at a length suitable for the radio broadcast to be received.

Even during the expansion and contraction operation of the antenna element 4, the front end circuit 11 and the amplifier circuit 17
etc. are powered on and ready to receive radio broadcasts. When the antenna element 4 is driven to expand and contract in this state, the antenna element 4 comes into sliding contact with the storage tube 6, which generates electrostatic noise and other noises that are harsh on the ears. To solve these problems, the present invention provides a muting circuit 20 in conjunction with the resistor 15. In the switching transistor 21 constituting the muting circuit 20, its collector is connected to the resistor 15 and the line 16 of the amplifier circuit 17, and its emitter is grounded.

The power of the storage battery 22 is supplied by a two-circuit interlocking switch 23.
The power is supplied from one contact 24 to the front end circuit 11, the amplifier circuit 17, etc., and these are energized. The other contact 25 of the two-circuit interlocking switch 23 is connected to a relay coil 27 of a relay 26 . This relay 26 has two relay switches 28 and 29. One relay switch 28 has a common contact 30 and individual contacts 31, 32, the individual contact 31 is connected to the individual contact 34 of the detection switch 9, and the individual contact 32 is connected to one terminal 5a of the motor 5. Ru. A common contact 35 of the detection switch 9, which is a cut-off means, is connected to the other terminal 5b of the motor 5, and an individual contact 36 is connected to an individual contact 37 of the other relay switch 29. The individual contacts 32 of the relay switch 28 and the individual contacts 38 of the relay switch 29 are connected to one terminal 5a of the motor 5, and are also connected to the base of the transistor 21 via a lead wire 50 from a diode 39, which is a blocking means. be done. The common contact 35 of the detection switch 9 is also connected to the base of the transistor 21 via the lead 50 from the blocking means diode 40. Relay switch 29
The common contact 41 of is grounded.

The switching mode of the movable contact 42 of the detection switch 9 is changed when the antenna element 4 reaches the upper limit position or the lower limit position. That is, for example, when the common contact 35 and the individual contacts 34 are electrically connected and the antenna element 4 is extended to the upper limit position and reaches its maximum length, the switching mode changes and the common contact 35 and the individual contacts 36 are electrically connected. is conductive and held as it is.

In order to receive radio broadcasting with the receiving device 1 having such a configuration, the two-circuit interlocking switch 23 is manually operated with the antenna element 4 housed in the housing tube 6, and the contacts 24 and 25 are closed. Conduct. As a result, the front end circuit 11, the amplifier circuit 17, etc. are energized via one contact 24, and become ready to receive radio broadcasts. Also, the relay coil 27 of the relay 26 is energized via the other contact 25, and the relay switch 28 is activated.
The common contact 30 of the relay switch 29 is electrically connected to the individual contact 31, and the common contact 41 of the relay switch 29 is electrically connected to the individual contact 38. On the other hand, since the antenna element 4 is at the lower limit position, the common contact 35 of the detection switch 9 is electrically connected to the individual contact 34. Therefore, storage battery 2
2 is supplied to the contacts 30, 3 of the relay switch 28.
1 - Contacts 34, 35 of detection switch 9 - Motor 5
- flows through contacts 38 and 41 of relay switch 29 in order, energizing motor 5 and extending antenna element 4;

At this time, the potential of the common contact 35 of the detection switch 9 becomes high level, and a mute signal is output from the diode 40 via the lead wire 50, making the transistor 21 of the muting circuit 20 conductive. As a result, the signal received by the antenna element 4 is bypassed by the transistor 21 and is not applied to the amplifier circuit 17, so that the noise generated by the expansion of the antenna element 4 is transmitted from the speaker 18 to the audible signal. be prevented from becoming

When the extended antenna element 4 reaches the upper limit position, the switching mode of the detection switch 9 is changed, the common contact 35 is brought into conduction with the individual contact 36, the individual contact 34 is cut off, and the power energization of the motor 5 is stopped. At the same time, the transistor 21 is cut off, and the received signal received by the antenna 2 is converted into sound from the speaker 18.

To end radio broadcast reception, manually operate the two-circuit interlocking switch 23 and close the contacts 24 and 25.
cut off. With this, the front end circuit 1
1, the amplifier circuit 17, etc. are deenergized. Also, the relay 26 is demagnetized, the common contact 30 of the relay switch 28 is brought into conduction with the individual contact 32, and the common contact 41 of the relay switch 29 is brought into conduction with the individual contact 37. On the other hand, the common contact 35 of the detection switch 9 is electrically connected to the individual contacts 36. Therefore, storage battery 2
2 is supplied to the contacts 30, 3 of the relay switch 28.
2-Motor 5-Detection switch 9 contacts 35, 36
- The current flows through the contacts 37 and 41 of the relay switch 29 in this order, and the motor 5 is energized to rotate in the opposite direction to that when the antenna element 4 is extended, thereby retracting the antenna element 4. At this time, the potential of the contact 32 of the relay switch 28 becomes high level, and a muting signal is output from the diode 39 via the lead wire 50, and the muting circuit 20
The transistor 21 is made conductive. As a result, the signal received by the antenna element 4 is bypassed by the transistor 21, and the signal received by the antenna element 4 is bypassed by the amplifier circuit 17.
Therefore, when the front end circuit 11, the amplifier circuit 17, etc. are maintained powered by smoothing capacitor discharge etc. and radio broadcast reception is continued, the antenna element is reduced. This prevents the noise generated by the noise from being turned into sound by the speaker 18.

When the reduced antenna element 4 reaches the lower limit position, the switching mode of the detection switch 9 is changed, the common contact 35 is brought into conduction with the individual contact 34, the individual contact 36 is cut off, and the power energization of the motor 5 is stopped. At the same time, the transistor 21 is cut off. In this way, the noise generated when the antenna element 4 expands and contracts is prevented from becoming audible from the speaker 18, and radio broadcasts can be comfortably received.

Further, a detection switch 9 is provided adjacent to the antenna element 4, and this detection switch 9 allows
the antenna element 4 extends to an upper limit position;
Alternatively, when it is detected that the antenna element 4 has been contracted to the lower limit position, power energization of the motor 5 is stopped. can be reliably expanded and contracted to a predetermined upper limit position or lower limit position. Furthermore, when the upper limit position or the lower limit position is reached, the power energization of the motor 5 is immediately stopped, thereby preventing the motor 5 from being overloaded and preventing damage to the motor 5. be able to.

FIG. 3 is a block diagram showing the electrical configuration of a receiving device 51 according to another embodiment of the present invention, and FIG. 4 is a sectional view of the vicinity of the antenna 52. This embodiment is similar to the previous embodiment and corresponding parts are provided with the same reference numerals. In this embodiment, in order to detect expansion and contraction of the antenna element 4, detection switches 53 and 54 are provided near both ends of the housing tube 6 in the axial direction, respectively. First contact 5 of detection switch 53
The second contact 56 is closed when the antenna element 4 extends and reaches the upper limit position, and is conductive otherwise.The second contact 56 is conductive when the antenna element 4 reaches the upper limit position, and is otherwise conductive. It is shut off when . The first contact 57 of the detection switch 54 is cut off when the antenna element 4 contracts and reaches the lower limit position, and is conductive at other times, and the second contact 58 is closed when the antenna element 4 contracts and reaches the lower limit position.
It becomes conductive when reaches the lower limit position, and is cut off at other times. A first contact 55 of the detection switch 53 is interposed between the individual contact 31 of the relay switch 28 and the motor 5, and a second contact 56 is interposed between the storage battery 22 and the diode 39.
A first contact 57 of the detection switch 54 is interposed between the individual contact 37 of the relay switch 29 and the motor 5, and a second contact 58 is interposed between the storage battery 22 and the diode 40. Diode 39, 40
The output of the inverting buffer 59 is inverted and applied to the base of the transistor 21. Connection points 60 and 61 between second contacts 56 and 58 of detection switches 53 and 54 and diodes 39 and 40 are grounded via resistors 62 and 63, respectively.

In order to receive radio broadcasting with the receiving device 51 having such a configuration, the two-circuit interlocking switch 23 is manually operated with the antenna element 4 housed in the housing tube 6, and the contacts 24 and 25 are made conductive. do. As a result, the front end circuit 11, the amplifier circuit 17, etc. are energized via the contact 24, and become ready to receive radio broadcasts. Also, the relay coil 2 of the relay 26 is connected via the contact 25.
7 is energized, and the common contact 3 of the relay switch 28
0 is electrically connected to the individual contact 31, and the relay switch 29
The common contact 41 is electrically connected to the individual contact 38 . On the other hand, since the antenna element 4 is at the lower limit position, the first contact 55 of the detection switch 53 is conductive. Therefore, the power of the storage battery 22 is transferred from the contacts 30 and 31 of the relay switch 28 to the detection switch 53.
- first contact 55 - motor 5 - relay switch 29
contacts 38 and 41 in this order, energizing the motor 5 and extending the antenna element 4.

At this time, the second contact 56 of the detection switch 53 is disconnected, and the second contact 56 of the detection switch 53, which was conducting, is
The second contact 58 is also cut off, and the potentials at the connection points 60 and 61 both become low level, and the diodes 39 and
The output of the inverting buffer 59 becomes high level through the inverting buffer 40, thereby making the transistor 21 of the muting circuit 20 conductive. As a result, the signal received by the antenna 2 is bypassed by the transistor 21 and is not applied to the amplifier circuit 17, so that the noise generated by the extension of the antenna element 4 is audible from the speaker 18. be prevented from being done.

When the extended antenna element 4 reaches the upper limit position, the first contact 55 of the detection switch 53 is cut off, power energization of the motor 5 is stopped, and the first contact 57 of the detection switch 54 is made conductive.
Further, the second contact 56 of the detection switch 53 becomes conductive, the potential at the connection point 60 becomes high level, the output of the inverting buffer 59 becomes low level, the transistor 21 is cut off, and the signal received by the antenna element 4 is The sound is generated from the speaker 18.

To end the reception of radio broadcasting, the two-circuit interlocking switch 23 is manually operated to cut off the contacts 24 and 25. As a result, the front end circuit 11
And the amplifier circuit 17 etc. are deenergized. Also, the relay 26 is demagnetized, the common contact 30 of the relay switch 28 is brought into conduction with the individual contact 32, and the common contact 41 of the relay switch 29 is brought into conduction with the individual contact 37.
On the other hand, the first contact 57 of the detection switch 54 is conductive. Therefore, the electric power of the storage battery 22 is transmitted through the contacts 30 and 32 of the relay switch 28 - the motor 5 - the first contact 57 of the detection switch 54 - the relay switch 2
9 contacts 37 and 41, the motor 5 is energized with power so that the direction of rotation is opposite to that when the antenna element 4 is extended, and the antenna element 4 is contracted.

At this time, the second contact 58 of the detection switch 54 is cut off, and the detection switch 53, which is conducting,
The second contact 56 is also cut off, and the potentials at the connection points 60 and 61 both become low level, and the diodes 39 and
The output of the inverting buffer 59 becomes high level through the inverting buffer 40, thereby making the transistor 21 of the muting circuit 20 conductive. As a result, the signal received by the antenna element 4 is bypassed by the transistor 21 and is not given to the amplifier circuit 17, so that the front end circuit 11, the amplifier circuit 17, etc. maintains power energization and prevents noise generated by the reduction of the antenna element 4 from being audible from the speaker 18 as radio broadcast reception continues.

When the reduced antenna element 4 reaches the lower limit position, the first contact 57 of the detection switch 54 is cut off, power energization of the motor 5 is stopped, and the first contact 55 of the detection switch 53 is made conductive.
Further, the second contact 58 of the detection switch 54 becomes conductive, the potential at the connection point 61 becomes high level, the output of the inverting buffer 59 becomes low level, and the transistor 21 is cut off. In this way, the noise generated when the antenna element 4 expands and contracts is not turned into sound by the speaker 18, and radio broadcasts can be comfortably received.

Fig. 5 is a block diagram showing the electrical configuration of a receiver 71 according to another embodiment of the present invention. This embodiment is similar to the embodiment shown in Fig. 1, and the same reference numerals are used for corresponding parts. In this embodiment, the outputs of the diodes 39 and 40 are applied to a processing circuit 72, which controls the conduction/cutoff operation of the transistor 21 of the muting circuit 20. This processing circuit 72 also controls the volume control circuit 13 which is realized by an electronic volume or the like.

FIG. 61 is a diagram showing the conduction/cutoff operation of the transistor 21 of the muting circuit 20.
FIG. 2 is a diagram showing the output level of the low frequency amplifier circuit 17. At time t1, two-circuit interlocking switch 2
3 becomes conductive, the extension of the antenna element 4 is started by the rotational drive of the motor 5 as described above, the potential at the connection point 35 of the detection switch 9 becomes high level, and the processing circuit 72 receives this mute signal. is received through the diode 40, the transistor 21 of the muting circuit 20 is turned on to perform a muting operation, and the output of the volume adjustment circuit 13 is controlled so as to be minimized.

When the antenna element 4 reaches the upper limit point at time t2, the switching mode of the detection switch 9 changes and the mute signal is no longer input to the processing circuit 72. As a result, the processing circuit 72 shuts off the transistor 21 to cancel the muting operation, and gradually increases the output of the volume adjustment circuit 13 to a preset value as time passes. When the output of the volume adjustment circuit 13 recovers to the preset value at time t3, the speaker 18
The radio broadcast is converted into sound at an appropriate volume.

When reception of the radio broadcast ends and the two-circuit interlocking switch 23 is cut off at time t4, the antenna element 4 starts to be reduced by the reverse rotation drive of the motor 5, and the potential of the contact 32 of the relay switch 28 becomes high. The processing circuit 72 receives this mute signal via the diode 39, conducts the transistor 21, performs a muting operation, and controls the output of the volume adjustment circuit 13 to the minimum level.

When the antenna element 4 reaches the lower limit position at time t5, the switching mode of the detection switch 9 changes, and the mute signal is no longer input to the processing circuit 72. At this time, the front end circuit 11, the low frequency amplifier circuit 17, etc. are already deenergized.

In this way, the noise generated when the antenna element 4 expands and contracts will not be audible from the speaker 18, and loud sound will not be suddenly emitted from the speaker 18 after the muting operation is completed, allowing comfortable radio broadcasting. can be received.

Effects As described above, according to the present invention, while the antenna means is expanding and contracting, the receiving means is disabled.
Therefore, it is possible to comfortably receive radio broadcasts, etc., without noise generated by the expansion and contraction operations of the antenna becoming audible.

Further, according to the present invention, since the mute signal is transmitted by detecting the application of a high or low level potential to both terminals of the driving means, the mute signal can be represented by the high or low level potential,
Therefore, by using a single lead wire for the mute signal, it is possible to reliably prevent noise from becoming audible without unnecessarily increasing the number of lead wires.

Furthermore, since a cutoff means is provided adjacent to the antenna means for cutting off the power supply to the driving means when it is detected that the antenna means is extended to the upper end or contracted to the lower end, the actual expansion and contraction operation of the antenna means is detected. and it is possible to detect that the antenna means has expanded or contracted by an accurate predetermined amount. Therefore, reliable expansion and contraction can be achieved without being affected by battery voltage, temperature, etc., and overloading of the driving means can be reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the electrical configuration of a receiving device 1 according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the vicinity of the antenna 2, and FIG. 3 is a block diagram of a receiving device 51 according to another embodiment of the present invention. 4 is a sectional view of the vicinity of the antenna 52, FIG. 5 is a block diagram showing the electrical configuration of a receiving device 71 according to still another embodiment of the present invention, and FIG. FIG. 7 is a waveform diagram for explaining the operation of the receiving device 71 shown in the figure. 1, 51, 71... Receiving device, 2, 52... Antenna, 3... Vehicle body, 4... Antenna element, 5... Motor, 6... Storage cylinder, 7... Drive member, 8... Winding up Reel, 9, 53, 54...Detection switch, 11...Front end circuit, 12...
...detection circuit, 13 ... volume adjustment circuit, 17 ... low frequency amplification circuit, 18 ... speaker, 20 ... mutating circuit, 21 ... transistor, 22 ...
...Storage battery, 23...Two-circuit interlocking switch, 26...
...Relay, 39, 40...Diode, 50...
Lead wire, 59... Inversion buffer, 72... Processing circuit.

Claims (1)

[Claims for Utility Model Registration] An extendable and retractable antenna means mounted on an automobile and having two input terminals, which can be forward or reverse depending on the direction of application of a ground potential and a high or low level potential to each terminal. a drive means that is capable of rotating in a direction and drives the antenna means to expand and contract; a receiving means for receiving a signal from the antenna means; detecting the application of a high or low level potential to both terminals of the driving means; blocking means for disabling the receiving means and applying a mute signal to the receiving means via a lead wire for preventing the receiving means from making the received signal audible when a level potential is applied; An automobile receiving device characterized by the following.