JPH057116A - Equalizer - Google Patents

Abstract

PURPOSE:To confirm the equalizer characteristic visually by displaying the frequency characteristic imparted from a signal transmission circuit onto a display device for a signal level for only a prescribed time in response to the operation of an operation key. CONSTITUTION:When one of preset keys on a display panel 2 corresponding to an equalizer characteristic respectively is depressed while the display panel 2 displays a signal level, the content of a preset memory in a RAM 23 of a microcomputer 20 is read and written in an output data memory in the RAM 23. In this case, an analog switch 13 is controlled by a control data written in the preset memory and a relevant equalization characteristic is imparted to an audio signal. Simultaneously, the content of the display output memory in the RAM 23 is rewritten to display the equalization characteristic onto the display section of the display panel 2 for a prescribed time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphic equalizer suitable for car audio equipment such as car stereos.

[0002]

2. Description of the Related Art In-vehicle audio equipment in which an AM / FM radio, a tape recorder, etc. are integrated is known as a so-called car stereo, and has become an indispensable accessory in the modern automobile civilization. In addition, the demand for Hi-Fi conversion for audio equipment also extends to car stereos, and as devices with excellent acoustic characteristics are being used, the correction of acoustic characteristics in automobiles and the change of frequency characteristics by a program will occur. With regard to correction, too, careful consideration has been required, and as a result, car stereos are also equipped with graphic equalizers.

This graphic equalizer (hereinafter, GE
(Q) divides the frequency band of the audio signal into a number of frequency bands, that is, channels, and changes the level characteristic for each channel so that the frequency characteristic over all bands can be changed arbitrarily. In many cases, a combination of a simulated inductor with an operational amplifier and a bridge amplifier is adopted, and the above requirement can be met by providing this GEQ in a car stereo.

By the way, in this GEQ, since a large number of variable resistors or switches for adjustment are provided corresponding to the above-mentioned channels, it requires a great deal of skill in its operation, and it is still cumbersome and troublesome. It is a simple operation. Therefore, it is not only a great psychological burden for the user to repeatedly operate the GEQ in accordance with the change of the program, but also for the car stereo such as a car stereo, in terms of safety of car operation. Therefore, there is a fear that it will be extremely unfavorable.

Therefore, in order to solve such a problem, data corresponding to various frequency characteristics to be obtained by GEQ is previously set in a memory or the like,
A so-called presettable GEQ is known in which an arbitrary frequency characteristic can be given only by the operation of selecting one of preset data when necessary. This presettable GEQ (hereinafter PGEQ
According to the above), since it can be easily and safely operated by providing it on a car stereo, etc. and can provide the required equalization characteristics, it can fully demonstrate the functions of an audio device equipped with GEQ. It is possible to fully enhance the performance and quality of stereos.

[0006]

[Problems to be Solved by the Invention] However, on the other hand,
In such a conventional PGEQ, since the equalization characteristic is given by the control data read from the memory, the frequency characteristic which is currently given immediately from the position of the operation key on the operation panel surface as in the normal GEQ is determined. It is not possible to know whether or not such characteristics are present, and, of course, what is the operating state and operating characteristics of the audio signal source that is the source of the audio signal to be input to the signal transmission circuit? There was a drawback in knowing that you couldn't do anything at all.

The object of the present invention is, except for the above-mentioned drawbacks of the prior art, what frequency characteristic is currently given to an audio signal, regardless of the position of the operation key on the operation panel surface. An object of the present invention is to provide an equalizer device which can be immediately known and at the time of writing a control data, an equalizing characteristic according to the control data is automatically displayed.

[0008]

In order to achieve this object, the present invention provides a two-dimensional display device which shows the control data supplied to the signal transmission circuit and the signal level of each band obtained at the output of the signal transmission circuit. In the PGEQ which can be switched and displayed by means of the display device, when the operation key is operated while the display device is displaying the signal level of each band, the display device displays the frequency characteristic given by the signal transmission circuit. The display is made only for a predetermined time.

[0009]

[Function] When new control data is written to the memory, its frequency characteristic is always displayed automatically, and it is possible to check it with the eyes, preventing the wrong characteristic from being given. can do.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of an equalizer device according to the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment in which the present invention is embodied by microcomputer (microcomputer) control. 1 is a GEQ unit, 2 is a control unit, and 3 is a level detection unit. In the GEQ unit 1, 10 and 11 are R channel and L channel audio signal input terminals, 12 is a bridge amplifier, 13 is an analog switch, 14 is a simulated inductor, 15 is a mute circuit, and 16 and 17 are R.
It is an audio signal output terminal of channel and L channel.

In the control unit 2, 20 is a microcomputer, 21
Is a central processor unit (CPU), and 22 is a read-only memory (RO) for storing programs.
M), 23 are random access memories (RAM), 2
4 is an input / output device (I / O), 25 is a switch part of the PGEQ operation panel, 26 is a display part of the operation panel, 27
Is a data latch. The level detector 3 will be described later.

Next, the operation will be described. The bridge amplifier 12 constitutes a GEQ signal transmission circuit and has independent signal transmission circuits for the R channel and L channel signals, respectively, and is connected to the simulated inductor 14 by the analog switch 13 to provide a large number of all audio signal bands. Frequency channels, for example, divided into five types of channels, and the signal passage amount for each channel is controlled according to the switching state of the analog switch 13,
Arbitrary frequency characteristics are given.

The mute circuit 15 is an analog switch 13.
Is provided to eliminate a transitional change in the audio signal output that occurs when the equalizing characteristic given by the bridge amplifier 12 changes stepwise. Therefore, the audio signals supplied from the input terminals 10 and 11 are subjected to a predetermined equalizing process according to the switching state of the analog switch 13 and output terminals 16 and 17.
To be operated as a GEQ.

Next, the operation of supplying the control data A to the analog switch 13 will be described. The switch section 25 of the operation panel is configured as shown in FIG.
a to 25e are slide encoders, 25f is a memory key, 25g to 25k are preset keys, 25l (l is 1
It's an El.) Is a f-feature / level key. The slide encoders 25a to 25e are for adjusting the amount of attenuation or gain for each of the five types of frequency channels,
Nine kinds of control data are generated in 4 bits according to the slide position, and the control data at this time is adapted to correspond to the output level.

The memory key 25f is a switch used when the control data representing the output level for each frequency channel set by the slide encoders 25a to 25e is stored in a predetermined address of the RAM 23 of the microcomputer 20. The data stored at this time requires an output level of 4 bits for each of the 5 channels, resulting in a total of 20 bits.

The preset keys 25g to 25k are RAM2
The address No. 3 is designated, and the control data is read from that address, and when the memory key 25f is pressed, the control data set by the slide encoders 25a to 25e is written to the corresponding address of the RAM 23. Work. Here, the f special / level key 25l is for switching the display contents, which will be described in detail later. All of these keys 25f to 25l are of the so-called touch switch type.

The display unit 26 comprises a matrix display 26a shown in FIG. 2 and indicator lights 26f to 26l provided in the respective keys 25f to 25l, of which the matrix display 26a is (5.times.9). Individual dot-like display elements 26a
It is a display device capable of two-dimensional display in which (1) is arranged in a matrix. The data latch 27 is the I / O2 of the microcomputer 20.
The data written via 4 is held and supplied to the analog switch 13 and the mute circuit 13.

The RAM 23 of the microcomputer 20 is provided with the following four types of memory areas.

(1) Current data memory A memory for storing the control data output from the slide encoders 25a to 25e according to the current operation position. (2) Output data memory Memory that stores the control data currently output to the data latch.

(3) Preset memory A memory for storing five types of independent control data corresponding to the preset keys 25g to 25k. (4) Display output memory Matrix display 26a and respective display lamps 26f-2
Memory to store display data for 6l.

Therefore, now, the slide encoder 25a
25e are operated, the contents of the current data memory are rewritten accordingly. At this time, the memory key 25
When neither f nor the preset keys 25g to 25k are operated, the contents of the present data memory are directly supplied to the output data memory.

As a result, these slide encoders 2
In response to the operations of 5a to 25e, the control data from them are directly transmitted to the analog switch 1 via the data latch 27.
3, the equalizing characteristic for the audio signal can be directly and arbitrarily controlled.

Further, at this time, the contents of the output data memory are given to the display output memory, whereby the display element 26a (1) of the display 26a, as shown in FIG. 3, is attenuated by each frequency channel ( Or, one display element is turned on in response to each of the gains) to display what the currently applied frequency characteristics are. Next, when the memory key 25f is pressed in this state, the indicator lamp 26f lights up for about 5 seconds, indicating that the memory is available during that time.

Then, following this, the preset key 25
When any one of the keys g to 25k is pressed, any one of the indicator lights 26g to 26k of the pressed key is turned on, and the contents of the current memory are written in the corresponding preset memory. And at the same time, memory key 2
The 5f indicator light 26f goes out, indicating that the memory is no longer available. If the preset keys 25g to 25k are not pressed within 5 seconds after the memory key 25f is pressed, the indicator lamp 26f is turned off. Also, these preset keys 25g-25
Only two or more of the k indicator lights 26g to 26k are turned on at the same time, and when two or more preset keys 25g to 25k are pressed at the same time, only the indicator light of the key that has been pressed to the end is turned on. ing.

When any one of the preset keys 25g to 25k is pressed and one of the corresponding indicator lamps 26g to 26k is lit in this manner, at this time, the contents of the preset memory corresponding to the key are read out to output the output data. Since the analog switch 13 is controlled by the control data written in the preset memory at this time, the equalizing characteristic corresponding to the analog switch 13 is given to the audio signal. At the same time, the contents of the display output memory are also overwritten with the contents of the output data memory, so that at this time, the equalizing characteristics given by the preset keys 25g to 25k are displayed on the display 26a.

On the other hand, the indicator light 26f of the memory key 25f
When is not lit, that is, without pressing this key, or after 5 seconds or more have elapsed, press the preset key 25g.
When any one of ~ 25k is pressed, the contents of the corresponding preset memory are directly given to the output data memory regardless of the state of the slide encoders 25a-25e, that is, the contents of the current data memory. The analog switch 13 is controlled by the control data stored in advance, that is, the preset data, and the corresponding equalizing characteristic is given, and it is displayed by the display 26a. For writing these preset data, the slide encoders 25a to 25e and the memory key 25f, and the corresponding preset keys 25g to 2g
What can be done by the operation of 5k is as described above.

The slide encoder 25a is operated when the indicator lamps 26g to 26k of any one of the preset keys 25g to 25k are lit, that is, when the equalizing characteristic is set by the preset data.
When any one of ˜25e is operated, the control state by the preset data is reset and the contents of the current data memory are written in the output data memory. You will be able to make adjustments to give.

The above-mentioned operations are all performed by the program written in the ROM of the microcomputer 20, and the CPU 21 of the microcomputer 20 executes I / O.
Input and output of the input data to and from the switch unit 25, the display unit 26, and the data latch 27 via 24 are performed in accordance with a predetermined procedure, and further, writing of data to the RAM 23 and reading of data from it are necessary. Carry out processing.

Therefore, according to this embodiment, the frequency characteristics by the GEQ equipped in the car stereo or the like can be arbitrarily adjusted by the slide encoders 25a to 25e, and the five types of equalization set in advance can be performed by this. The characteristics can be arbitrarily selected by one-touch operation of the preset keys 25f to 25k, and the matrix display 26a shows the characteristics of the frequency characteristics currently given to the audio signal as shown in FIG. Since it is displayed, it is possible to always grasp the operating state sufficiently.

By the way, in the above-mentioned embodiment, the level detector 3 is provided, which allows the matrix display 26 to operate.
With a, the level of the output audio signal can be independently displayed for each channel of the GEQ. Therefore, this point will be described below. In FIG. 1, 30 is an adder circuit, 31 is a bridge amplifier,
32 is an analog switch, 33 is a simulated inductor, and 34 is an analog-digital converter (A / D).

The adder circuit 30 synthesizes the R channel and L channel audio signals obtained at the output of the bridge amplifier 12 into a signal of 1 channel, and the bridge amplifier 3
Supply to one input.

Bridge amplifier 31, analog switch 3
2, the simulated inductor 33 may be the same as the bridge amplifier 12, the analog switch 13, and the simulated inductor 14, respectively, and when the analog switch 32 is controlled by the control data B from the data latch 27 of the control unit 2, each channel of the GEQ is controlled. , Which operates so as to be sequentially switched as five types of band pass filters having the pass band in the frequency band of the analog switch 32 as shown in FIG.
32a of the simulated inductor 33 are sequentially and substantially periodically switched, so that the inductors 33a to 33 of the simulated inductor 33 are switched.
One of e is selectively switched to be connected to the bridge amplifier 31. As a result, when it is connected to the inductor 33a, only the signal of the 60 Hz component of the audio signal IN is taken out to the output L _A. 250H when the inductor 33b is connected.
z component, and 1 kHz in inductor 33c,
Inductor 33d has 3.5 kHz, inductor 33e
Then, 10 kHz is taken out to the output L _A , respectively.

Therefore, at the output L _A , an analog signal representing the level of each channel of the audio signal from the adder circuit 30 appears successively and cyclically.
The A / D 34 receives the analog signal of the output L _A as an input and converts it into 4-bit digital level data L _D.

Therefore, the switch section 2 of the operation panel is now
When you press the f special / level key 25l provided in 5,
The signal from this key 25l is read by the microcomputer 20 through the I / O 24, and first the indicator lamp 26l of the display memory is read.
The contents corresponding to the above are rewritten and the indicator lamp 26l is turned on to indicate that the display mode of the display 26a has changed from the frequency characteristic display mode (the display mode shown in FIG. 3) until then to the level display mode. .. At the same time, the display operation program is switched by the input from the f special / level key 25l, the microcomputer 20 sends the control data B to the analog switch 32 via the data latch 27, and sequentially outputs the audio signals of the respective channels to the A / D 34. To the RAM 2 and input the digital level data L _D
Write to 3 display output data memory.

As a result, the display elements 26a (1) corresponding to the respective channels of the matrix display 26a are sequentially turned on in the form of a bar graph in the number corresponding to the level of the audio signal of that channel, as shown in FIG. Operates to display the level of each channel dynamically. Therefore, according to this embodiment, the output level for each frequency band of the audio signal can be displayed by operating the f special / level key 25l as necessary, and the operating state of the car stereo can be displayed in various ways. It is possible to obtain a good usability by grasping the information.

In this embodiment, when the f special / level key 25l is first pressed, the indicator light 26l is turned on to enter the level display mode, and when the indicator light 26l is next turned on, this display is made. The light 26l is extinguished and the mode is switched to the frequency characteristic display mode. Furthermore, when the memory key 25f is pressed and when the preset key 25g.
When any one of 25k is pressed, the frequency characteristic display mode is automatically changed for about 5 seconds thereafter, and during that period, the input by the f special / level key 25l is not accepted. As a result, new control data is obtained. When writing to the preset memory and when the GEQ equalize characteristic is set by the preset control data, the frequency characteristic can always be checked with eyes to prevent giving the wrong characteristic. You can

Needless to say, in such a device using a microcomputer, initialization is required to start the program operation from a predetermined operation each time the power is turned on. If the memory contents are random, preset key 2
The equalization characteristic given when pressing 5g to 25k becomes random, and an unpleasant sound may be reproduced from the car stereo or the like when the power switch is turned on. Further, if the preset data disappears each time the power is turned off, it is necessary to repeat the memory operation each time, which is complicated.

Therefore, in the above embodiment, the RAM 23 is of a power back-up type by means of battery so that the data of the RAM 23 can be saved regardless of the ON / OFF of the power source of the car stereo or the like, whereby the power switch is turned off. The next time you turn it on, the preset key 2
By pressing 5g to 25k, the preset data is immediately given, and the required equalizing characteristic can be given with one touch while checking the display 26a.

In the above embodiment, the power supply back-up method of the RAM 23 is used, and the state of the preset keys 25g to 25k immediately before the power supply is turned off is determined by the RAM 23.
Stored in a predetermined memory area of the RAM 23, and the contents of the predetermined memory area of the RAM 23 are determined by the program at the time of the initialization operation when the power switch is turned on next. Before that, it was made to be the same as when the power was turned off.

As a result, the state immediately before the power is turned off is determined by the slide encoders 25a to 25e.
When the equalization characteristic of is being given, that is, when the contents of the data memory are currently being read to the output data memory, the operation will be started in that state also when the power is turned on next time, and the power switch One of preset keys 25g-25k when is turned off
When the indicator lamps are lit and the equalizing characteristics are given by the contents of the preset memory corresponding to them, the indicator lamps of the preset key will light when the power is turned on again. The equalization characteristic is given by the contents of the set memory to start the operation, and the operation becomes extremely easy, and
The high-quality mood of the device can be sufficiently enhanced.

Further, in the above embodiment, the microcomputer 2
The ROM 22 of 0 or a ROM different from the ROM 22 is provided, and standard preset data is stored in the ROM 22 and stored in the preset memory area of the RAM 23 in the initialization operation program when the power is turned on. The control data is examined, and if it is meaningless data, a program for reading the standard control data stored in the ROM and writing it in the preset memory area of the RAM 23 may be added. Good.

According to this, when the user turns on the power switch for the first time after shipment from the factory or when the power is turned on for some reason such as a failure of the backup power supply, the RAM 2 is turned on.
In any case when the control data stored in the preset memory area of 3 is destroyed, the equalizing characteristic can always be kept in a predetermined state and the abnormal sound is prevented from being reproduced. You can

Next, such an audio signal input to the PGEQ is usually supplied from the car stereo tape deck and further supplied from the FM-AM tuner or the like. Therefore, as an embodiment of the present invention, the display mode by the matrix display 26a of the display unit 26 is switched not only to the frequency characteristic display mode and the level display mode described above, but also to the tape deck operation display mode and the tuner operation display mode. You may use it. FIG. 6 shows an embodiment thereof, in which 40 is a tape deck, 41 is a tuner, 42 and 43 are analog-digital converters (A / D), and others are the same as the embodiment of FIG.

Various data representing the operating state or operating state of the tape deck 40, such as volume (VOL), balance (BAL), sound quality (BASS, TRE), fader
The data D such as (FADER) is left as it is, and the signal level L _RL is supplied to the microcomputer 20 via the A / D 42.
Incorporated by I / O24. The same applies to the tuner 41, the data T representing the tuning frequency remains unchanged, and the signal level L _S is introduced into the microcomputer 20 via the A / D 43.

FIG. 7 shows an embodiment of the switch section 25 and the display section 26. The switch section 25 has a deck display key 25m and a tuner display key 25n in addition to the f special / level key 25l.
On the other hand, in the display unit 26, on the other hand, the matrix display 26a is formed by a two-dimensional display unit having 8 × 9 display elements 26a (1), and further, the indicator lights 26m and 26n of the keys 25m and 25n, and It consists of an illumination part for identifying the display content, and this illumination part is the EQ display part 26a (2).
, A deck display portion 26a (3), a tuner display portion 26a (4), and tuner tuning frequency display portions 26a (5), 26a (6).

Therefore, when the deck display key 25m is pressed, it is read by the program of the microcomputer 20 and the program for the display unit 26 is switched to the deck display, so that the indicator lamp 26m is turned on and at the same time the deck display portion is displayed. 26a (3) is illuminated. The key 25
When neither m nor 25n is pressed, the EQ display portion 26a (2) is illuminated. Then, at this time, as shown in FIG.
OL, BAL, BASS, TRE, etc. are display elements 26a.
It is displayed according to the vertical lighting position of (1), and at the same time, the signal levels L and R of the left channel and the right channel are displayed in a bar graph shape.

When the tuner display key 25n is pressed, the indicator light 26n is turned on and the tuner display portion 26a (4) is illuminated, and the tuning frequency is changed according to the operating state of the tuner 41 as shown in FIG. Display part 26
One of a (5) and 26a (6) is illuminated, the tuning frequency is displayed by the lighting position of one display element 26a (1) in the horizontal direction, and the level of the received signal is in the horizontal bar graph. It will be displayed in a shape. When the f special / level key 25l is pressed, the EQ display portion 26a (2) is illuminated, and at this time, the GEQ equalization characteristic and the level display are alternately switched each time the key 25l is pressed. Is the same as in the embodiment of FIG.

Therefore, according to this embodiment, in the car stereo with a tuner, all the operating states and operating states can be known by the display unit 26, and the operation is always simple and always accurate. be able to. In the above embodiment, the control data for the GEQ is set by the slide encoders 25a to 25e. Instead of this, an encoder that is automatically operated by the up / down keys may be used. You can

As the matrix display 26a, any one such as a light emitting diode, a liquid crystal, a fluorescent display tube may be used, and in some cases, a cathode ray tube may be used.

[0050]

As described above, according to the present invention,
Even in PQEQ, which uses the preset control data in the memory to set the required equalization characteristics with one touch, the set equalization characteristics are immediately displayed, and when new control data is written to the memory, the Since the frequency response will be displayed automatically, you can easily check it with your eyes.
It is possible to surely prevent incorrect characteristics from being given, and except for the drawbacks of the prior art, accurate operation can always be easily obtained. Therefore, it is possible to obtain a high-grade PGEQ with excellent usability. Car stereo etc. can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an equalizer device according to the present invention.

FIG. 2 is a front view showing an example of an operation panel according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a frequency characteristic display mode according to an embodiment of the present invention.

FIG. 4 is a block diagram showing an example of a level detection unit according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a level display mode according to an embodiment of the present invention.

FIG. 6 is a block diagram showing another embodiment of the present invention.

FIG. 7 is a front view showing an example of a display unit according to another embodiment of the present invention.

FIG. 8 is an explanatory diagram of a display mode according to another embodiment of the present invention.

FIG. 9 is an explanatory diagram of a display mode according to another embodiment of the present invention.

[Explanation of symbols]

 1 Graphic equalizer section 2 Control section 3 Level detection section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukihiko Urikawa 1-7 Yukiya Otsuka-cho, Ota-ku, Tokyo Alpine Electronics, Inc.

Claims (1)

Claim: What is claimed is: 1. A signal transmission circuit capable of controlling frequency characteristics over substantially the entire audio signal frequency band by electrical control data, and memory means capable of writing and reading the control data. And operation input means for generating the control data including operation keys for writing the frequency characteristic given to the signal transmission circuit to the memory means and for controlling writing and reading of the control data to and from the memory means. In the graph equalizer device that has the
The display device is provided with a display device capable of two-dimensional display and level detection means for dividing the signal obtained at the output of the signal transmission circuit into a plurality of frequency bands and independently detecting the signal level of each band. An equalizer characterized in that, when the operation key is operated while displaying the signal level of each band, the frequency characteristic given by the signal transmission circuit is displayed by the display device for a predetermined time. apparatus.