JPH0681128U - Equalizer device - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To improve the operability of the equalizer device. [Structure] In order for the user to read the desired frequency characteristic data, first of all, an update corresponding to the desired frequency band
Operate the down key 25. When the signal by this key operation is input to the microcomputer 5, the display unit 23 is switched from the level display to the EQ display, and the frequency characteristic data stored until then is displayed. When the display unit 23 is switched to the EQ display, desired up / down keys 25 can be sequentially operated while confirming the characteristic data on the display unit 23. Then, after the operation of the up / down key 25 is completed and the desired frequency characteristic data is read, when a predetermined time, for example, 3 seconds has passed, the display unit 23 is switched from the EQ display to the level display, and the music being reproduced is reproduced. Show level. Thereby, the frequency characteristic data desired by the user can be set.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a graphic equalizer suitable for car audio equipment such as car stereos.

[0002]

[Prior art]

 In-car audio equipment that integrates AM / FM radio, tape recorder, etc. 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 has spread to car stereos, and as equipment with excellent acoustic characteristics has come to be used, it is necessary to correct the acoustic characteristics in the car and change the frequency by a program. With respect to the correction of characteristics, careful consideration has also been required, and as a result, car stereos are also equipped with graphic equalizers.

This graphic equalizer (hereinafter referred to as GEQ) divides the frequency band of an audio signal into a number of frequency bands, that is, channels, changes the frequency characteristic for each channel, and sets the frequency characteristic over all bands to an arbitrary value. In general, operational amplifiers that use a combination of simulated inductors and bridge amplifiers are often adopted. By installing this GEQ in a car stereo, the above requirements can be met. You can By the way, since this GEQ is provided with a large number of variable resistors or switches for adjusting the frequency characteristics corresponding to each of the above-mentioned channels, it requires a considerable amount of skill in its operation, and is still cumbersome and troublesome. It is a simple operation.

Therefore, when the program is changed, the repeated GEQ operation according to the change does not only impose a considerable psychological burden on the user, but also, especially as an in-vehicle device such as a car stereo, a vehicle operation is performed. There was a risk that it would be extremely unfavorable from the viewpoint of safety.

Therefore, in order to solve such a problem, data corresponding to various frequency characteristics to be obtained by GEQ is set in a memory in advance and one of preset data is selected when necessary. A so-called presettable GEQ capable of giving an arbitrary frequency characteristic only by performing the operation is proposed as, for example, Japanese Patent Application No. 56-118276.

According to the presettable GEQ (hereinafter, referred to as PGEQ), the GEQ can be installed in a car stereo or the like and can be operated easily and safely to always give a required equalization characteristic accurately. It is possible to fully demonstrate the functions of an audio device equipped with a car, and to fully enhance the performance and luxury of car stereos.

Therefore, a method of providing a ROM (Read Only Memory) on the PGEQ and setting control data giving standard equalizing characteristics at the manufacturing stage of a car stereo or the like has been considered.

However, as is well known, the sound reproduction characteristic of an audio device such as a car stereo greatly depends on the sound characteristic of the space itself, such as the passenger compartment of an automobile, in which the sound or the like should be reproduced from the device. Moreover, these characteristics have changed greatly depending on the vehicle type and usage.

Therefore, in the method in which the ROM or the like is used to give a predetermined equalizing characteristic at the time of manufacturing as described above, a predetermined sound reproduction characteristic is actually used when the vehicle is used as a car stereo or the like in the passenger compartment of an automobile. There was a drawback that only different characteristics could be obtained.

Therefore, in order to eliminate this drawback, a method has been considered in which a user can write control data having an arbitrary equalizing characteristic in a memory different from the ROM of the PGEQ as described above.

However, even in such a PGEQ, the preset operation of the control data has many man-hours, is complicated, and is inconvenient.

This is because the GEQ display panel displays the equalization characteristic (hereinafter referred to as EQ display) and the output display level of the audio signal in GEQ (hereinafter referred to as level display). Conventionally, a switch for switching between the EQ display and the level display is arranged. For example, voice, music, etc. are being reproduced, and the PGEQ display panel displays the level. At this time, when the user wants to write a new equalization characteristic, first, the switch is used to switch the display panel to the EQ display, and then the up / down key or the preset memory key is used to obtain the desired equalization characteristic. To write the desired equalization characteristics to the memory and then display the level again with the switch. I had to switch.

[0013]

[Problems to be solved by the device]

 Therefore, as described above, when presetting new control data, it is necessary to switch the display panel to the EQ display once, reset the level display again after the preset operation, which is also inconvenient. There was a drawback.

[0014]

[Means for Solving the Problems]

 SUMMARY OF THE INVENTION In the present invention, the above-mentioned problem is solved by the present invention: a signal transmission circuit whose frequency characteristic over almost the entire audio signal frequency band can be controlled by electrical control data, and a memory means capable of writing and reading the control data. An input operation section equipped with a preset key for reading out control data necessary for setting frequency characteristics in the signal transmission circuit from the memory means, and an up / down key for adjusting a gain in a desired frequency band. An equalizer device having a display section for selectively displaying the output level of the audio signal and the frequency characteristic set in the signal transmission circuit, wherein the preset key is displayed while the display section is displaying the output level of the audio signal. Is set in the signal transmission circuit on the basis of the control data read from the memory means. The possible frequency characteristics are displayed on the display unit for a predetermined time, and the output level of the audio signal is displayed on the display unit for a predetermined time after the up / down key is operated while the frequency characteristics are being displayed on the display unit. This is solved by providing a control unit that operates.

[0015]

[Action]

 When the preset key is operated while the display unit is displaying the output level of the audio signal, the control unit displays the frequency characteristic that can be set in the signal transmission circuit on the display unit for a predetermined time based on the control data read from the memory means. In addition to displaying, the output level of the audio signal is displayed on the display unit when a predetermined time has elapsed after the up / down key was operated while the frequency characteristic was being displayed on the display unit.

[0016]

【Example】

 Embodiments of an automatic equalizer device according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention under the control of a microcomputer (microcomputer), 1 is a bridge amplifier, 2 is an analog switch, 3 is a simulated inductor, 4 is a 4-bit data latch, 5 is a microcomputer, 6 is a keyboard device configured with key matrix, 7 is a decoder, 8 is a display device, 9 is a segment driver, 10 is a digit driver, 11 is a band pass filter, 12 is an analog switch, and 13 is an A / D (analog). Digital converter), 14, 15 are muting circuits, 16 is a pink noise generator, 17 is a microphone, 18 is a head amplifier, 19 is a line amplifier, and 20 is an auto equalizer latch.

The bridge amplifier 1 is coupled to the n simulated inductors 3 through the n analog switches 2, and the audio signal frequency band is coupled to a large number of channels, for example, n kinds of simulated inductors 3. The signal frequency band is divided into a large number of channels, for example, n types of channels, the attenuation amount (or gain) of each channel is controlled according to the switching state of the n analog switches 2, and the audio from the input terminal IN is input. The signal is given an arbitrary frequency characteristic and transmitted to the output terminal OUT. Therefore, by supplying predetermined control data to the analog switch 2, it operates as a GEQ.

The microcomputer 5 includes a CPU (central processor unit), a ROM for storing programs, a RAM (random access memory) for storing data, and an I / O (input / output device). The processing is performed by a predetermined program according to the input data from the keyboard device 6 in which the key matrix is configured, and the control data input from the keyboard device 6 is written into, for example, a 4-bit data latch 4 and stored in the RAM. Writing to a predetermined memory area, writing of control data read from a predetermined memory area of RAM to data latch 4, etc., and switching control of analog switch 2 by control data from data latch 4 I do. Therefore, by operating the keyboard device 6, data corresponding to various frequency characteristics to be obtained as a GEQ is set in a memory or the like in advance, and one of preset data is selected when necessary. It is possible to configure a presettable GEQ (hereinafter referred to as PGEQ) capable of giving the frequency characteristic of.

The display device 8 is a device capable of two-dimensional display, such as a matrix display device. The display data is given from the microcomputer 5 via the segment driver 9 and the digit driver 10, and the analog switch via the data latch 4. The display corresponding to the control data given in No. 2 is performed, and the frequency characteristic currently given by the GEQ is displayed. Therefore, even when the preset control data is selected by the keyboard device 6 and the equalize characteristic is given thereby, the equalize characteristic can be directly grasped directly and visually and the control can be correctly performed. become.

The n band-pass filters 11 have pass characteristics corresponding to n types of GEQ channels, respectively, and are sequentially and periodically switched by the analog switch 12, and equalized to the output of the bridge amplifier 1. The signal of each channel of the audio signal that appears is sequentially selected and supplied to the A / D 13, converted into a digital signal by the A / D 13 and input to the microcomputer 5.

Therefore, the microcomputer 5 detects the signal level of each channel of the output audio signal and selectively supplies it to the display device 8 as display data by input from the keyboard device. As a result, it is supplied to the display device 8 as display data. As a result, the display device 8 is switched to the above-mentioned frequency characteristic display mode by the input from the keyboard device 6, and when the output signal level display mode is switched, the level of the output signal for each channel is changed. The operation status can be grasped in real time by displaying them side by side in a bar graph.

In the above operation state, the operation signals for the data latch 4, the segment driver 9, and the analog switch 12 are supplied from the microcomputer 5 via the decoder 7, and at the same time, to the keyboard device 6. A signal is supplied from the decoder 7, and the lighting control of the indicator lamps indicating the operation states of various keys is also performed. The segment driver 9 is for selecting a display element in the vertical direction of the display device 8, and the digit driver 10 is for selecting a display element in the horizontal direction.

The above is a description of the normal operation of the PGEQ, and the operation of the automatic equalizer device according to the present invention will be described below. The muting circuits 14 and 15 operate by a signal from an auto equalizer switch (not shown) arranged in the keyboard device 6, and the muting circuits 14 and 15 are turned on during the normal PEGQ operation described above. However, when the auto equalizer switch of the keyboard device 6 is turned on and the automatic preset operation mode is selected, the muting circuits 14 and 15 are turned on and the audio signal transmission path is cut off, and at the same time pink noise is generated. The device 16 is driven. The pink noise generator 16 generates a test signal including all frequency components having substantially equal levels over almost the entire audio signal frequency band. The microphone 17 is installed in a car cabin or the like, which is a listening room where an audio device such as a car stereo equipped with this PGEQ is installed, and is exposed to a sound field formed by a speaker of the audio device to generate a voice signal. Detect.

Therefore, it is assumed that the keyboard device 6 is now operated and switching to the automatic preset operation mode is input. As a result, the auto equalizer latch 21 is held and an auto equalizer mode command is input to the microcomputer 5 to switch the operation program. Then, first, data is supplied to the data latch 4 and the muting circuits 14 and 15 are turned on to cut off audio signals and the like. When this auto equalizer mode command is output, the display device 8 is in the level display. As a result, the signal of the pink noise generator 16 is supplied from the output terminal OUT to the power amplifier of the audio equipment such as a car stereo through the line amplifier 19, and the pink noise signal drives the speaker to generate the sound field in the listening room. After being formed, it is detected by the microphone 17 and becomes an electric signal, which is supplied to the input of the band pass filter 11 via the head amplifier 18. Then, the bandpass filter 11 divides the pink noise signal into frequency bands.

At the same time, the microcomputer 5 supplies data to the data latch 4 to control the analog switch 2 so that the characteristics of the bridge amplifier 1 become flat in the entire band, for example, gain in each channel. Is set to zero (or the attenuation is zero).

Therefore, at this stage, the level of each frequency of the signal appearing at the output of the bridge amplifier 1 is the same as that of a listening room such as a passenger compartment of an automobile in which a sound field is formed by an audio device such as a car stereo. It represents the overall frequency characteristics including acoustic characteristics.

Next, the microcomputer 5 supplies data to the analog switch 12 via the decoder 7, sequentially selects n bandpass filters 11, and outputs the signal extracted from the output of the head amplifier 18 via the A / D 13. , The signal level of each channel is detected, the control data given to the analog switch 2 is determined according to the detection result, and the frequency characteristic of the signal appearing at the output of the bridge amplifier 1 is a predetermined characteristic, for example, A nearly flat characteristic should be obtained within the audio signal frequency band.

Therefore, for this reason, the microcomputer 5 supplies data to the analog switch 12, selects a bandpass filter 11 of a reference frequency channel, for example, a channel of 800 Hz from n, and outputs a signal of this channel. When the level of this signal reaches 0 dB level, in other words, when the best tuning is performed, the levels of all other frequency bands are read to the microcomputer 5 when the level of this signal is taken in via the A / D 13. , Frequency characteristics are generated by a predetermined calculation.

This is because the microcomputer 5 sequentially supplies data to the analog switch 12 and sequentially selects filters other than the 800 Hz band-pass filter 11 that has become the reference channel, and is input via the A / D 13 each time. The signal level is compared with the reference value, and the difference is logarithmically converted and inversely corrected. (For channels with a signal level higher than the reference value, the amount of attenuation is given according to the difference, and channels with a To the analog switch 2 via the data latch 4. Note that the data may be written in a predetermined memory area of the RAM as needed.

After the new frequency characteristic data is created in this way, a signal for releasing the auto equalizer latch 21 from the microcomputer 5 and the muting circuits 14, 15 are turned off to restore the audio signal and the like. And a signal for stopping the pink noise generator 16 is issued.

Therefore, after that, it will operate as a normal PEGQ, and by operating the up / down switch for each channel provided in the keyboard device 6, as a normal GEQ and preset. It can be used as PGEQ by selectively reading the control data stored in memory by the key.

Next, the operation of the PGEQ will be described with reference to FIGS. 2 and 3. FIG. 2 is a diagram showing an operation panel of the PGEQ, in which 22 is a casing, 23 is an EQ display and a level display. The display unit 23 corresponds to the display device 8. 24 is a sensor, and the sensor 24 corresponds to the microphone 17. 25 is a plurality of up / down switches for adjusting the level of each frequency obtained by dividing the audio frequency band into a number of channels, 26 is a switch, and the switch 26 is an automatic preset as an automatic equalizer. It is for switching to the mode. Reference numeral 27 denotes a memory key. Each memory key 27 has different predetermined frequency characteristic data stored in it and is used for reading out each memory. A memory enable key 28 is for writing desired frequency characteristic data. Reference numeral 29 is a preset memory key, and when the preset memory key 29 is turned on, for example, when the memory key 27a of the memory keys 27 is turned on, the frequency characteristic stored in the memory key 27a is stored. The data is read.

The above-mentioned up / down key 25, the switch 26, the memory 27, the memory enable key 28, and the preset memory key 29 constitute the keyboard device 6.

In the present embodiment, the six memory keys 27 can read out two kinds of memories corresponding to ON / OFF of the preset memory keys 29. Therefore, the preset memory keys 29 can be read. In combination with and, 12 kinds of memories can be read out by the 6 memory keys 27.

Next, a procedure for the user to read desired frequency characteristic data will be described. The flowchart of this procedure is shown in FIG. Now, assuming that music is being reproduced, the display unit 23 is a level display that displays the level of music reproduction. In this state, the user first operates the up / down key 25 corresponding to the desired frequency band as the first step in order to read the desired frequency characteristic data. When the signal by this key operation is input to the microcomputer 5 (see FIG. 1), as a second step, the display unit 23 is switched from the level display to the EQ display, and the frequency characteristic data stored until then is displayed. It Then, when the display section 23 is switched to the EQ display, desired up / down keys 25 can be sequentially operated while confirming the characteristic data on the display section 23 as the next third step. As a fourth step, while the up / down key 25 is being operated, the timer inside the microcomputer 5 is reset every time, for example, 0.5 seconds.

Then, after the operation of the up / down key 25 is completed and the desired frequency characteristic data is read, if a predetermined time of, for example, 3 seconds has passed in the next step, the display unit 23 displays the EQ as the next step. The display is switched to the level display and the music level being played is displayed. As a result, the frequency characteristic data desired by the user can be set.

The flowchart of FIG. 3B is a chart when the preset memory key 29 is operated. The difference from FIG. 3A is that it is up / down in the third step of FIG. 3A. Instead of operating the key 25, in this chart, the memory corresponding to the operated preset memory key 29 is called. The other steps are the same as those in the chart of FIG. 3 (a). Even during this operation, when the preset memory key 29 is operated, the display unit 23 once switches to the EQ display and this time is displayed. It is held for the set predetermined time, and if there is another key input within the predetermined time, the EQ display on the display unit is extended, and then the level display is returned again.

As described above, in the automatic equalizer device of the present invention, when the frequency characteristic data is newly set in the state where the display section is performing the level display, the update for setting the frequency characteristic data is performed.・ When the down key 25 is operated, the display section automatically switches from the level display to the EQ display. Similarly, when the switch 26 for the automatic equalizer and the preset memory key 29 are operated, the display section is also changed. In No. 23, the level display is interrupted and replaced with the EQ display, and after a predetermined time, the level display is automatically restored.

[0039]

[Effect of device]

 As described above, according to the present invention, a signal transmission circuit whose frequency characteristics over almost the entire audio signal frequency band can be controlled by electrical control data, and a memory means capable of writing and reading the control data, Input operation section provided with a preset key for reading out control data necessary for setting frequency characteristics from the memory means to the signal transmission circuit, and an up / down key for adjusting gain in a desired frequency band. And an equalizer device having a display section for selectively displaying an output level of the audio signal and a frequency characteristic set in the signal transmission circuit, wherein the preset section is displayed while the display section is displaying the output level of the audio signal. When the key is operated, the frequency that can be set in the signal transmission circuit based on the control data read from the memory means. A control for displaying a number characteristic on the display unit for a predetermined time and displaying an output level of an audio signal on the display unit for a predetermined time after the UP / DOWN key is operated while the frequency characteristic is being displayed on the display unit. Since the unit is provided, the operability of the equalizer device, in which the adjustment of the frequency characteristic is frequently performed depending on the genre of music listened to, is further improved. Further, since it is possible to omit the display switching dedicated key, it is possible to save space on the operation surface of the device and reduce the cost, and also to obtain a more suitable equalizer device especially when it is used for a vehicle.

[Brief description of drawings]

FIG. 1 is a block diagram of an equalizer device of the present invention.

FIG. 2 is a diagram showing an operation panel of the equalizer device.

3A and 3B are flowcharts showing an operation procedure of the equalizer device.

[Explanation of symbols]

 1 bridge amplifier 2 analog switch 3 simulated inductor 4 data latch 5 microcomputer (microcomputer) 6 keyboard device 8 display device 11 bandpass filter 12 analog switch 13 A / D (analog-digital converter) 14 muting circuit 15 muting circuit 16 Pink noise generator 17 Microphone 19 Line amplifier 21 Auto equalizer latch 23 Display

[Procedure amendment]

[Submission date] April 27, 1994

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a block diagram of an equalizer device of the present invention.

FIG. 2 is a diagram showing an operation panel of the equalizer device.

3A and 3B are flowcharts showing an operation procedure of the equalizer device.

[Explanation of symbols] 1 bridge amplifier 2 analog switch 3 simulated inductor 4 data latch 5 microcomputer (microcomputer) 6 keyboard device 8 display device 11 bandpass filter 12 analog switch 13 A / D (analog-digital converter) 14 muting Circuit 15 Muting circuit 16 Pink noise generator 17 Microphone 19 Line amplifier 21 Auto equalizer latch 23 Display

[Procedure 3]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

Claims (1)

[Scope of utility model registration request] 1. A signal transmission circuit capable of controlling frequency characteristics over substantially the entire audio signal frequency band by electrical control data, memory means capable of writing and reading the control data, and the signal from the memory means. An input operation section having a preset key for reading out control data necessary for setting frequency characteristics in the transmission circuit, an up / down key for adjusting gain in a desired frequency band, and an output level of an audio signal In an equalizer device having a display section for selectively displaying the frequency characteristic set in the signal transmission circuit, the memory means when the preset key is operated while the display section is displaying an output level of an audio signal. Predetermined frequency characteristics that can be set in the signal transmission circuit based on the control data read from And a control unit for displaying the output level of the audio signal on the display unit when a predetermined time elapses after the up / down key is operated while the frequency characteristic is being displayed on the display unit. Equalizer device characterized by.