JPH0458204B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a receiving station presetting device for a tuner.

BACKGROUND TECHNOLOGY In the case of a tuner that can freely select preset channels, a received signal is detected in advance by using a reception station search function by frequency sweep such as scan or seek, and the sweep is temporarily stopped and the frequency corresponding to the reception frequency at that time is detected. One method is to store the signal in memory and start sweeping again to detect the received signal. In this method, if there is a limit to the memory capacity, that is, the number of storage areas, the memory capacity may be exceeded before sweeping over all the frequencies of the reception band, and therefore the remaining When there is a broadcasting station with a higher electric field strength in a frequency band, there is a drawback that preset selection cannot be performed for reception of this broadcasting station.

Summary of the Invention [Object of the Invention] The present invention has been made to eliminate the drawbacks of the conventional ones. It is an object of the present invention to provide a receiving station presetting device for a tuner that can preset in the order of magnitude or frequency.

[Summary of the Invention] A receiving station presetting device according to the present invention is a receiving station presetting device for a tuner capable of automatic channel selection, which selects a station by calling a pre-stored signal indicating a receiving station from a memory. , a frequency sweep means for sweeping the reception frequency to achieve reception within the reception frequency band; and a level signal representing the reception signal level and reception frequency, respectively, when a reception signal of a predetermined level or higher is obtained during this sweep period. and a signal generating means for generating a pair of frequency signals, and a storage means for storing the pairs of the level signal and the frequency signal in order of magnitude of the level signal, respectively, the number of the level signals to be stored by the storage means exceeds the capacity of the storage means, the storage means compares the stored level signal group with the current level signal currently generated by the signal generation means and selects a storage level smaller than this current level. By shifting the maximum level signal in the signal group and the level signals following it one rank at a time, and then placing the current level signal at the rank immediately before the maximum level signal, It is characterized in that a level signal group and a frequency signal pair group including a level signal and a frequency signal pair corresponding thereto are arranged and stored in the order of high and low received signal levels.

Embodiments Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram showing an embodiment of the present invention, in which an antenna reception signal is converted into an IF (intermediate frequency) signal at a front end 1 and input to an IF amplifier 2. As shown in FIG. The output of the IF amplifier 2 is detected by a detector 3 and demodulated into an audio signal. The tuning frequency of an RF tuning circuit (not shown) and the oscillation frequency of a local oscillator in the front end 1 are controlled by the output of a PLL (phase locked loop) circuit 4, and the tuner is configured using a so-called PLL synthesizer system. ing.

In this example, a command device 5 is provided to issue a preset memory operation command, and the command output activates a sweep controller 6 to enable reception from the minimum frequency to the maximum frequency of the reception band. ,
A control signal to the PLL 4 (designating a signal for controlling the division ratio of a programmable divider in the PLL) is automatically varied to sweep the reception frequency.

The IF carrier level in the IF amplifier 2 is detected by the level detector 7, and a carrier level detection signal is derived only when a carrier higher than a preset audible threshold level exists. This detection signal is digitized by an A/D (analog-digital signal) converter 8 and written to a memory 10 that stores an Ls signal (level signal corresponding to the IF carrier level) via a memory R/W controller 9. . A frequency signal (referred to as an fs signal) indicating the reception frequency at this time is written from the sweep controller 6 to the fs memory 11 via the controller 9.

A memory number counter 12 is provided, which sequentially counts the number of writes to the memories 10 and 11, and when the number of writes reaches the memory capacity, generates a predetermined signal and sends this signal to the salt calculation processor 13. Send out. In this arithmetic processor 13, when the number of memory writes exceeds the memory capacity, the current data from the A/D converter 8 is
The Ls signal is compared with the Ls signal of the current memory content that was previously input and stored, and if the current Ls signal is smaller than the minimum value, no change is made to the memory content; conversely, if it is larger than the minimum value, If so, the minimum value Ls
Remove the signal from memory and instead use this current Ls
It has the function of writing signals to memory. memory 11
, the current fs signal at that time is the minimum level signal.
It is replaced with the fs signal stored corresponding to Ls.

FIG. 2 is a flowchart showing the operations of blocks 9 to 13 in FIG. In response to a command signal from the command unit 5, the counter 12 is reset to "0" and the sweep is started from the minimum frequency of the receiving band (corresponding to A and B in the figure). In step C, it is determined whether the maximum frequency has been reached, and if it has not reached the maximum frequency, the receiving state is entered. In this receiving state D, the audio output is muted to eliminate inter-office noise, but this is not particularly shown.

At E, it is determined whether the number of writes to the memory has reached the memory capacity (5 in this example). This is done by the output of the counter 12. If the memory capacity has not reached 5, proceed to F, and both Ls and fs signals are sent to each memory 1.
0 and 11, respectively. In this case, as shown in G, the memory contents of Ls and fs in each memory 10 and 11 are rearranged in descending order of IF carrier level. This operation is called a sorting operation based on the Ls level, and is performed by the arithmetic processor 13. At step H, the contents of the counter 12 are incremented by 1, and the process goes to step C again to repeat the above operations.

When the number of writes exceeds the memory capacity, the process moves to step I, and the subsequent Ls signal is compared with the Ls signal of the current memory contents, and if it is smaller, the process returns to step C. On the other hand, if the current Ls signal is larger than at least one of the Ls signals of the current memory contents, the current Ls signal is shifted to J.
It is determined whether the signal is larger than any of the Ls signals in the memory contents. Here, the current Ls signal
LsN, and the Ls signals in the memory contents are sequentially Ls1, Ls2, Ls3, Ls4, and Ls5 from largest to largest. If it is determined that Ls2>LsN>Ls3 in step J, then Ls3→Ls4, Ls4→Ls5, Ls
5→Remove from memory. Then, LsN is written to the empty Ls3 location in the memory and defined as a new Ls3, but the memory 11 for fs
Similar shifts and substitutions are made in . These are steps K and L, and I to L are performed by the arithmetic processor 13. After that, return to step C again.

When the reception frequency sweep reaches the maximum frequency, it advances to M and is arranged in memory in order of reception level.
It is determined whether or not the Ls and fs data are arranged in frequency order (lowest frequency order) (sorting operation by fs) (based on an external command), and if so, N is used to perform the sorting operation. Otherwise, the program will simply terminate.

By sorting by fs, the memory contents are arranged in order of high and low frequencies, and it is easy to ensure that the order of preset numbers is always in the order of high and low frequencies.

It is clear that blocks 9 to 13 in FIG. 1 can be easily realized by a so-called microcomputer or the like.

Figure 3 shows the frequency within a given reception band in a certain area.
FIG. 3 is a diagram showing an example of an IF carrier level, and the specific operation of the preset device of the present invention will be explained using this example. When the sweep is started from the lowest frequency fmin, the receiving station a whose frequency is higher than the audible attenuation point VT is first received, and its Ls and fs signals are stored as Ls1 and fs1, respectively. Next, receiving station b is received, and similarly Ls
2 and fs2 are stored in memory, but a level comparison is made between Ls1 and Ls2, and since Ls2 is larger, station b is defined as Ls1 and fs1, station a is defined as Ls2 and fs2, and they are sequentially stored. Since station c is below the VT level, it is ignored, and the next stations d to f are stored in memory in order of level.

When receiving station g, the memory capacity limit has been reached, so the data of station a, which has the minimum value of the current memory contents, is removed from the memory and a new station g is stored. The same applies to station h. If the above operation is Ls sort, each channel CH ₁ to _{CH 5} of the memory has
They are stored sequentially as d, g, h, e, and b. For fs sorting, each channel CH ₁ to _{CH 5}
are stored sequentially as b, d, e, g, and h.

Effects of the Invention As described above, according to the present invention, all the preset memories of the receiving station can be freely performed and can be preset within the memory capacity in descending order of electric field strength. It is possible to easily receive broadcasting stations with large electric field strengths. In particular, since the reception area of an on-vehicle tuner constantly moves, using the preset device of the present invention will automatically store a preset memory of an optimal group of receiving stations, thereby eliminating all the complexity of preset operations. Become. In addition, since the received station information is stored in memory in the order of high and low levels, the receiver can easily select stations with high sensitivity and in the order of received levels, and furthermore, the operation of displaying the channel selection is also facilitated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the embodiment of the present invention, and FIG. 3 is an electric field distribution of a broadcasting station to explain the specific operation of the present invention. It is a figure which shows the example of a state. Explanation of symbols of main parts, 4...PLL, 6...
Sweep controller, 7... Level detector, 10, 11...
...Memory, 12...Memory number counter, 13...
Arithmetic processor.

Claims (1)

[Scope of Claims] 1. A receiving station presetting device in a tuner capable of automatic tuning, in which a pre-stored signal indicative of a receiving station is recalled from a memory to select a station, which Frequency sweeping means sweeps the reception frequency to perform reception, and when a reception signal of a predetermined level or higher is obtained during this sweep period, generates a level signal and a frequency signal pair representing the reception signal level and its reception frequency, respectively. and storage means for storing pairs of the level signal and frequency signal in order of magnitude of the level signal, and the number of the level signals to be stored in the storage means is determined by the capacity of the storage means. , the storage means compares the stored level signal group with the current level signal currently generated by the signal generation means and determines the maximum level among the stored level signal groups that is smaller than the current level signal. The current level signal and the level signal following it are shifted backward by one rank, and then the current level signal is placed in the rank immediately before the highest level signal. A preset device characterized in that a level signal and a group of frequency signal pairs including corresponding frequency signal pairs are arranged and stored in the order of high and low received signal levels. 2. The preset device according to claim 1, wherein the storage means rearranges the already stored level signals and frequency pairs in order of high and low frequencies in accordance with a command.