JPH0269678A - Spectrum analyzer instrument - Google Patents

Abstract

PURPOSE:To display spectra of divided bands, the number of which is larger than the number of BPFs, in a miniaturized and inexpensive way by interpolating each signal level of components of frequencies which are different from the center frequency of each BPF. CONSTITUTION:A switching circuit 3 operates at the timing from a microcomputer 10 for arithmetic process and supplies outputs of M channels from BPFs 2A-2M to the computer 10 by M/2 bands by selectively switching the outputs. The computer 10 A/D-converts each signal level into level data for bar graphs. Then the computer 10 linearly interpolates each signal level of N kinds of frequency components, the frequencies of which are different from the center frequency of each BPF, based on the level data of the M bands by means of an interpolation processing section 15 and writes the level data of each frequency component of the (M+N) bands in a memory 16. Successively, the computer 10 displays (M+N) spectra in a displaying section 30. Therefore, spectra of divided bands, the number of which is larger than the number of BPFs, can be displayed in a miniaturized and inexpensive way.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a spectrum analyzer device installed in an audio system or the like.

B. Invention 1 Existing Summary The present invention is a spectrum analyzer device installed in an audio system, etc.
For each signal level of M types of frequency components obtained by band-pass filters, each signal level of N types of frequency bands different from each of the above-mentioned center frequencies is interpolated, and (
By displaying the signal levels of M+N) types of frequency components, it is possible to display a spectrum in which the number of divided bands is greater than the number of band-pass filters.

C. Conventional Technology In general, a spectrum analyzer device installed in an audio system, etc. analyzes an input signal into m types of frequency components and displays the spectrum using m band passes that divide the frequency band of a human signal into m parts. A filter is required, and each signal level of each filter output from the above band-pass filter is detected by an m-channel level detection circuit,
The signal level of the m types of frequency components is displayed, for example, as a bar bluff, on the display means in accordance with the detection output of each channel by the level detection circuit. Conventionally, functions such as a display control circuit for controlling the above-mentioned display means and the above-mentioned level detection circuit have been provided.
There is also a microcomputer dedicated to a spectrum analyzer that analyzes the frequency components into different types and displays a seven-band spectrum.

A spectrum analyzer device that analyzes wavenumber components and displays a spectrum requires m bandpass filters that divide the frequency band of an input signal into m. Normally, in a spectrum analyzer device installed in an audio system, there is no need to increase the accuracy of each band to that extent even when the number of hands is increased, but as the number of bands increases, the number of bandpass filters increases. There is a need,
Problems include an increase in the installation space and manufacturing cost of the bandpass filter.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional circumstances, the present invention aims to reduce the size and cost of a multi-hand spectrum analyzer device installed in an audio system, etc. The present invention provides a spectrum analyzer device with a new configuration that can display a spectrum with a large number of signals.

D. Problems to be Solved by the Invention By the way, as mentioned above, the spectrum analyzer device according to the present invention has three main problems, each with m types of input signals. M band-pass filters having different frequencies, level detection means for detecting the signal level of each filter output from the band-pass filter for a human signal, and N types of frequency components different from each center frequency of the band-pass filter. interpolation processing means for interpolating each signal level based on the level detection output from the level detection means to form signal level data of (M+N) types of frequency components; and the signal level data obtained by the interpolation processing means. display means for displaying signal levels of (M+N) types of frequency components according to the filter outputs of the M bandpass filters, and the display means displays signals of (M+N) types of frequency components in response to filter outputs from the M band-pass filters. It is characterized by level display.

F Function In the spectrum analyzer device according to the present invention, the level of the level detection means that detects each signal level of M types of frequency components in a human signal as the signal level of each filter output from M band pass filters with different center frequencies. Based on the detection output, the interpolation processing means interpolates each signal level of N types of frequency components different from each center frequency of the band pass filter to obtain signal level data of (M + N) types of frequency components. and display means,
The signal levels of (M+N) types of frequency components are displayed in accordance with the signal level data.

G. Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In the embodiment described below, the present invention is applied to a spectrum analyzer device built into a so-called audio visual (AV) amplifier, and the display on the front panel (100) of the amplifier as shown in FIG. The section (30) displays a spectrum of 22 bands.

The configuration of the spectrum analyzer device of this embodiment is shown in the block diagram of FIG. 1. Input signals are supplied from a signal input terminal (1), and the frequency bands of the input signals are different from each other. M (M=12) 12 band pass filters (2A), (2B
)...(2M) and the above bandpass filter (2A)
, (2B)...(2M) is inputted via a switch circuit (3) to a microcomputer (10) for arithmetic processing, and based on the arithmetic processing output from this microcomputer (10). The display above (
It is composed of a display microcomputer (20) that controls the operation of the drive section (25) (30).

The switching operation of the switch circuit (3) is controlled by a timing signal given from the arithmetic processing microcomputer (10), and the switching operation is controlled by the above-mentioned 12 band-pass filters (2A), (2B)...(2M). Each filter output (CI, ), (CH2)...(C
H + □) is selected and the filter output (C)l I )...(C116) / (CH
7) ... (CIll2) is supplied to the microcomputer (10) for the above-mentioned arithmetic processing.

Also, a microcomputer (10) for the above calculation processing.
has a built-in 6-channel analog/digital (A/D) conversion processor (II), and connects the switch circuit (3) from the bandpass filters (2A), (2B)...(2M). Filter output (CI
ll)...(Cl16) / (Cl1□)...(
CIll2) is converted to each signal level by the A/D conversion processing section (
11), the filter outputs (Cll l) 1 (C1l z) by the band pass filters (2A), (2B)...(2M) are digitized in units of 6 bands.
...(CL□) is detected, and the detection data of each signal level is written into the memory (12). In addition, a microcomputer (
10) includes a conversion processing unit (13) that converts each detection data written in the memory (12) into level data suitable for displaying the average level by, for example, a bar graph on the display unit (30). , this conversion processing unit (13
) is written into the memory (14). Furthermore, the microcomputer (10) for the above-mentioned arithmetic processing has the above-mentioned memory (1).
4) The above filter output (CH+) written in.

Based on level data for 12 bands corresponding to each signal level of (CH2)...(CH1□), what is the center frequency of each of the band communication filters (2A), (2B)...(2M)? It is equipped with an interpolation processing section (15) that interpolates each signal level of N (=10) different frequency components by linear interpolation processing, for example. The level data of each frequency component is written into the memory (16).

Furthermore, the display microcomputer (20)
Bar graph display data corresponding to the level data of each frequency component for the 22 bands formed by the arithmetic processing microcomputer (10) is read from a font memory (not shown), and the display section (30) is driven. Department (
25).

As shown in the schematic diagram of FIG. 3, the display section (30) has a bar graph level display area (LD) for 22 bands.
, ), (LD2)..., (LD!□),
By providing the bar graph display data for the 22 bands from the display microcomputer (20) to the driving section (25), the average signal level of each frequency component for the 22 bands is displayed as a bar graph, Displays a 22-band spectrum.

In addition, in the spectrum analyzer device of this embodiment, the bar graph level display area (
Each center frequency (r+
), (rz), . . . (f2□) are set as shown in Table 1.

and the bar graph level display area (LDI).

Each odd-numbered center frequency (f, ), (f3)...(h+) assigned to (LD:l)...(LDt,) is the above-mentioned 12 bandpass filters (2A), (2B )
...(2M) each center frequency.

Further, in the spectrum analyzer device of this embodiment, the display microcomputer (20) has a display control button (40) disposed on the front panel (100).
) When the control data is accepted, the display mode changes from the average value display mode, which displays the spectrum of 22 bands by bar graph display of the average signal level shown in Fig. 3 above, to the average value display mode shown in Fig. 4. As such, the peak value of each frequency component of 22 bands (PKl), (PKz)
... (PK!
The operating state is switched to the peak value display mode displayed in z□).

In addition, the microcomputer (lO
), the conversion processing unit (I3)
The processing by the interpolation processor (15) is exchanged with the processing by the interpolation processing unit (15), firstly, level data for 22 bands is formed by interpolation processing based on the level data for 12 bands, and later, level data for 22 bands is formed suitable for display. It is also possible to convert the data into level data.

H Effects of the Invention In the spectrum analyzer device according to the present invention, level detection means detects each signal level of M types of frequency components in an input signal as the signal level of each filter output from M bandpass filters having different center frequencies. Based on the level detection output, the interpolation processing means performs interpolation calculation on each signal level of N types of frequency components different from each center frequency of the band pass filter to obtain signal level data of (M+N) types of frequency components. Therefore, the display means displays the signal levels of (M + N) types of frequency components according to the signal level data, and the number of divided bands is larger than the number of band-pass filters (M). (M+N) spectrum display can be performed.

Therefore, by applying the present invention, it is possible to reduce the size and cost of a multiband spectrum analyzer device provided in an audio system or the like.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a spectrum analyzer device according to the present invention, FIG. 2 is a front view showing the front panel of an amplifier incorporating the spectrum analyzer device to which the present invention is applied, and FIGS. 3 and 4 are FIG. 4 is a schematic diagram showing an example of a display state of a display section of the spectrum analyzer device. (1)・・・・・・・・・・・・Signal input terminal (
2A) ~ (2M)... Recording amplifier (3).
・・・・・・・・・・・・・・・Switch circuit (10)
, (20)・・・・・・Microcomputer (11)・・・・・・・・・・・・D/A converter (
15)・・・・・・・・・・・・Interpolation processing unit (30
)・・・・・・・・・・・・Display section Figure 3

Claims (1)

[Claims] M band-pass filters each having a different center frequency; level detection means for detecting the signal level of each filter output from the band-pass filter with respect to an input signal; and M band-pass filters each having a different center frequency; interpolation processing means for performing interpolation calculation on each signal level of N different frequency components based on the level detection output by the level detection means to form signal level data of (M+N) types of frequency components; and the interpolation processing means display means for displaying the signal levels of (M+N) types of frequency components according to the signal level data obtained by the display means; A spectrum analyzer device characterized by displaying signal levels of M+N) types of frequency components.