JPH05122015A - Acoustic device - Google Patents

Abstract

PURPOSE:To make it possible to perform a preset/memory/scan for only channels from which more than a prescribed level receiving sensitivity can be obtained by providing a skip means skipping channels from which only less than a prescribed level receiving sensitivity can be obtained and moving to the next channels. CONSTITUTION:Sound output is performed for one of the output of reception frequency amplified by an intermediate frequency amplifier 15 by a speaker 20 via a detection circuit 18 and an audio amplifier 19. The other output is detected by a detection circuit 16, DC voltage is taken out according to an IF signal and the taken-out DC voltage is compared with reference value voltage Vref at a comparator 17. When the taken-out audio signal part has only receiving sensitivity of less than a prescribed level, a high level output signal is transmitted from the comparator 17 to a microcomputer 11. Thus, the microcomputer 11 skips a channel to be being received and starts a scan at the next channel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio device, and more particularly to a preset memory scan (hereinafter referred to as P.SCAN).
The audio device in which the tuner and the tape player are integrated with each other.

[0002]

2. Description of the Related Art Conventionally, electronically tuned car radios have been developed by P. SC
It has a function called AN. P. What is SCAN?
Channels for 5 to 6 stations are usually provided in the memory for each band (frequency band), and a function of sequentially receiving broadcast stations preset and written in the channels from the channel 1 for a predetermined time Is. Conventional P.I. In the SCAN function, once P. When SCAN is started, unless there is a stop operation from the user side on the way,
Make sure that all channels start from P. 1 in order.
It was SCAN.

[0003]

[Problems to be Solved by the Invention] The SCAN function has the following problems. (1) When the number of receivable broadcasting stations is less than the number of broadcasting stations (number of channels) that can be set in the memory. In this case, P. When the SCAN is operated, as described above, all the channels are P.S. Since SCAN is performed, channels for which broadcasting stations are not written are also P.S. It will be SCAN. Therefore, the user can confirm that the unwritten channel of the broadcasting station is P.P. During SCAN, I was heard a broadcast where I could only hear noise. (2) When the reception sensitivity of some broadcasting stations stored in the channel becomes low due to long-distance movement in a car. In this case, P. When SCAN is operated, the channel (broadcasting station) whose reception sensitivity is low becomes P.S. During SCAN, as in (1), the user is still heard a broadcast that hears very little noise. The present invention has been made in view of the above-mentioned problems, and the P.P. An object is to provide an audio device that performs SCAN.

[0004]

In order to achieve the above-mentioned object, an audio device according to the present invention is a P.I. In an audio device having a SCAN function and a search function, a normal P.S.P. It is characterized in that it has a skip means for performing a SCAN operation and skipping a channel for which a receiving sensitivity lower than a predetermined level is obtained and shifting to the next channel.

[0005]

According to the above configuration, the P. In an audio device having a SCAN function and a search function, a normal P.S.P. For a channel for which the SCAN operation is performed and the reception sensitivity is less than a predetermined level, there is a skip means for skipping the channel and moving to the next channel. SCA
During N, the user will not be made to hear a broadcast in which almost no noise is heard. For example, in an audio device in which five channels are prepared in the memory, P.P. When performing the SCAN, if the receiving sensitivity of the fourth and fifth channels is low, or if no receivable broadcasting station is written in the fourth and fifth channels, in the audio device according to the present invention, The first to third channels are P.S. SCANed, but the 4th and 5th channels are skipped without being received. Needless to say, the number of the skipped channel is not limited to the fourth or fifth number as in the above example, and an arbitrary numerical value from 1 to 5 can be taken according to the reception sensitivity level.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an audio device according to the present invention will be described below with reference to the drawings. FIG. 1A is a block diagram schematically showing the configuration of the audio device according to the present embodiment, and FIG. 1B shows an embodiment of a circuit for determining the level of reception sensitivity.

In FIG. 1A, the microcomputer 11 includes a memory 12, P. The SCAN switch 13 is connected, and CH in the memory 12 indicates a channel, and the numerical values 1 to n indicate channel numbers. A control signal line 21 is connected from the microcomputer 11 to the front end 14, and a signal line 22 is connected from the front end 14 to the microcomputer 11.
Are connected.

The antenna 10 is connected to the input side of the front end 14 and the IF amplifier 15 (intermediate frequency amplifier) is connected to the output side. The output line of the IF amplifier 15 is branched into two, and the detection circuit 18, the audio amplifier 19, and the speaker 20 are sequentially connected to one output line, and the detection circuit 16 is connected to the other output line. The output line of the detection circuit 16 is connected to the negative terminal of the comparator 17. The reference value voltage V _ref is connected to the positive terminal of the comparator 17,
The output line 7 is connected to the microcomputer 11.

P. When the SCAN switch 13 is pressed and an ON signal is transmitted to the microcomputer 11, the microcomputer 11 immediately outputs the P.S. The SCAN mode is entered, and the channels in the memory 12 are sequentially set from P.N. Start SCAN. In order to synchronize with each broadcast station and broadcast radio waves preset in each channel,
The tuning voltage is transmitted from the microcomputer 11 to the front end 14 via the control signal line 21, and the local oscillation frequency corresponding to the difference between the reception (tuning) frequency and the intermediate frequency is transmitted from the front end 14 via the signal line 22. It is transmitted to the computer 11. In this way, the frequency of the receiving broadcast station is converted into the intermediate frequency by the front end 14 and input to the IF amplifier 15 (intermediate frequency amplifier).

One output of the reception frequency (broadcasting station) amplified by the IF amplifier 15 is output as sound from a speaker 20 via a detection circuit 18 and an audio amplifier 19. The other output is detected by the detection circuit 16 to extract a DC voltage corresponding to the IF signal, and the extracted DC voltage is output to the minus side terminal of the comparator 17 and is connected to the plus side terminal. It is compared with the value voltage V _ref . If the audio signal component detected and extracted by the detection circuit 16 has a certain electric field strength (reception sensitivity) of a predetermined level or more, the low-level output signal from the comparator 17 has an electric field strength (reception sensitivity) of less than the predetermined level. ), The high-level output signal is transmitted from the comparator 17 to the microcomputer 11.

When the low-level output signal is transmitted from the comparator 17 to the microcomputer 11, this means that the receiving sensitivity of the broadcasting station to be received is higher than a predetermined level. Is P. SCAN is performed and voice output is performed for a fixed time (scan time). When the high-level output signal is transmitted from the comparator 17 to the microcomputer 11, this means that the receiving sensitivity of the broadcasting station to be received is less than a predetermined level, and as described later,
The channel currently being received by the microcomputer 11 is skipped, and the P.S.
SCAN is started.

FIG. 1B is a circuit configuration diagram schematically showing an example of the comparator 17, which is a portion for making a level determination of the receiving sensitivity and outputting an SD (station detector) signal to the microcomputer 11. In addition, SD
The signal is also a search stop signal.

The comparator 17 of this embodiment comprises a search sensitivity adjusting resistor 17a, a bias circuit 17b and a transistor 17c. As described above, the detection circuit 1
The DC voltage (electric field strength signal) detected and extracted in 6 according to the IF signal is adjusted and divided by the search sensitivity adjusting resistor 17a and further divided by the buffer circuit 17b and input to the base of the transistor 17c. To be done. If the signal voltage input to the base of the transistor 17c is higher than the base-emitter threshold voltage V _{BE of the} transistor 17c, the transistor 17c is turned on, and if the signal voltage is lower than the threshold voltage V _BE , the transistor 17c. Turn off. When the transistor 17c is off, a high level SD signal is output from the collector of the transistor 17c, and when it is on, a low level SD signal is output to the microcomputer 11.

As described above, when the transistor 17c is turned on, the potential of the collector is lowered, and a low-level SD signal is output to the microcomputer 11, this means that the receiving sensitivity of the receiving channel is above a predetermined level. Since this means that the channel is P. SCA
Then, the sound is output for a certain period of time. On the other hand, when the transistor 17c is turned off and a high-level SD signal is transmitted from the collector to the microcomputer 11, this means that the receiving sensitivity of the receiving channel is below a certain level, and therefore the microcomputer 1
1 skips the reception channel and transmits P.1 of the next channel. Start SCAN. The predetermined level is set by the search sensitivity adjusting resistor 17a.

As described above, in the audio device of this embodiment, it is possible to reliably judge whether the receiving sensitivity of the receiving channel is above a predetermined level or not, depending on the presence or absence of the SD signal, so that the receiving sensitivity is high. Channels below a certain level are always skipped. Therefore, P. SC
It is possible to prevent the user from listening to a broadcast during the AN in which almost no noise is heard.

FIG. 2 shows a P.I. of the microcomputer 11 relating to the audio device of the present embodiment. It is a flowchart which shows a SCAN function. First, P. It is determined whether the SCAN switch is turned on (step 1). P. Since the SCAN switch is a type of switch that returns to the original even if it is pressed,
Even if it is determined to be “N” in step 1, the P. May be in SCAN. In order to judge this, if "N" is judged in step 1, the process jumps to step 6. In step 6, P. If it is determined whether the SCAN is in progress, and if "N" is also determined in step 6, in this case, If not in SCAN, P. Since the SCAN switch is not in the operated state, P. The SCAN process is not performed, and the process returns to step 1 after performing other processes.

P. If the SCAN switch is turned on and it is determined to be "Y" in step 1, the process proceeds to step 2 and P.S. S
It is determined whether it is in CAN. If "Y" is determined in step 2, P. P.S. Since the SCAN switch has been turned on, the judgment result is Step 12.
, The receiving channel is fixed, and P. The SCAN mode ends (step 13). P. After the SCAN mode ends, other processing (step 15) is executed, and the process returns to step 1.

If "N" is determined in step 2,
From now on P. You must be prepared to start SCAN. In the audio device of the present embodiment, the P.O. When SCAN mode ends, P. Since it is restored to the state before entering the SCAN mode, first, the current state, for example, during reproduction by a tape player, receiving a specific channel, all-off state, etc. is stored in the memory (step 3). ). Then, P. In order to remember that you are in SCAN,
P. The SCAN flag is set in memory (step 4). Then, the channel number is set to 1 (step 5), and P. SCAN will be started.

P. When performing SCAN, first, a timer for determining the elapse of a certain time (scan time) is set (step 10). Next, whether the reception sensitivity of the reception channel is higher than a predetermined level, that is, S
It is determined whether the D (station detector) signal is at high level or low level (step 1).
1). The SD signal can be obtained, for example, by detecting the output of the IF amplifier 15 and comparing the detected signal level with a predetermined level.

If the SD signal is at a low level, this means that the receiving sensitivity of the receiving channel is above a certain level, and therefore the other processing (step 15), step 1 and step 6 are performed. Via step 7
Then, it is determined whether or not the fixed time set in step 10 has elapsed. If the fixed time has not elapsed, the processing is performed in a loop of step 7-step 15-step 1-step 6-step 7 until the fixed time has elapsed. During this period, the reception of the reception channel is continued and the sound of the reception broadcasting station is being output. In the process of the loop, the P. If the SCAN switch is turned on and it is determined to be "Y" in step 1, the determination result goes to step 12, and the reception channel is fixed and the P.S. The SCAN mode ends (step 13).

In the process of the loop, the P. SCAN
If a certain period of time has passed without the switch being turned on and it is determined to be "Y" in step 7, this means that the P.P. Since it indicates that SCAN has ended, P.S. The channel number is incremented by 1 to perform SCAN (step 8).

Further, if the SD signal is judged to be at the high level in step 11, it means that the receiving sensitivity of the receiving channel is below a certain level, and thus the channel number is also incremented by one. (Step 8) The reception channel is skipped.

Then, it is determined whether or not the number of the channel added 1 in step 8 becomes (n + 1).
It is judged by. If the channel number is less than (n + 1), this means that all channels are still P. SCA
Since it indicates that the channels are not exhausted, the channel having the number added to 1 in step 8 is P.N. SCAN. That is, a timer for judging the elapse of a certain time is set (step 10), and then the SD signal level is judged (step 11). Then, as described above, if the SD signal is at the high level, the process proceeds to step 8 and the channel number of the receiving channel is incremented by 1. If the SD signal is at a low level, the P.S. SCAN processing is performed. Also in this route, as in the case of the above loop, the P. When the SCAN switch is turned on and it is determined to be "Y" in step 1, the processing route shifts from step 1 to step 12, the reception channel is fixed, and P.
The SCAN mode ends (step 13).

In the above processing route, P. If the SCAN switch is not turned on for a certain period of time (step 7), the channel number is incremented by 1 (step 8), and the incremented channel number becomes (n + 1), all the data stored in the memory is prepared. The channel of P. Since it has been SCANed, P. The SCAN mode ends (step 14), and the initial state set in step 3 is restored (step 16).

As described above, the P.I. In the SCAN function, the level of the SD signal is determined to determine whether the receiving sensitivity (electric field strength) of the receiving channel is high or low. It is always skipped without SCAN. Therefore, as in the conventional case, the P. It is possible to reliably prevent the audio output of a broadcast almost equal to noise during the SCAN for a certain period of time.

[0026]

As described above in detail, in the audio device according to the present invention, the P.I. In an audio device having a SCAN function and a search function, a normal P.S.P. SCA
For the channel for which the N operation is performed and the reception sensitivity is less than a certain predetermined level, there is a skip means for skipping the channel and moving to the next channel. A channel for which only receiving sensitivity is obtained is P.P. It is possible to surely skip without SCAN. Therefore,
P. It is possible to prevent the user from listening to a broadcast during SCAN in which almost no noise is heard in a channel with low reception sensitivity.

[Brief description of drawings]

1A and 1B show an embodiment of an audio device according to the present invention, FIG. 1A is a block diagram schematically showing the configuration of the audio device according to the embodiment, and FIG. It is a block diagram which showed an example of a comparator circuit.

FIG. 2 is a diagram illustrating a P.I. of an audio device according to an embodiment. It is a flowchart which shows a SCAN function.

[Explanation of sign]

11 Microcomputer 12 Memory 13 Preset Memory Scan (P.SCAN) Switch 17 Comparator (Reception Sensitivity Level Judgment Circuit)

Claims (1)

[Claims] 1. An audio device having a preset memory scan function and a search function, wherein a normal preset memory scan operation is performed only on a channel for which a reception sensitivity of a predetermined level or higher is obtained, and a reception sensitivity of a level lower than a predetermined level. An audio device characterized by having skip means for skipping the channel obtained only and shifting to the next channel.