JPH026447B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a graphic equalizer for in-vehicle audio equipment such as a car stereo.

Car audio equipment that integrates an AM/FM radio, tape recorder, etc. is known as a car stereo, and has become an almost indispensable accessory in the modern automobile civilization.

In addition, the demand for high-fidelity audio equipment extends to car stereos, and as devices with superior acoustic characteristics come into use, it is becoming increasingly important to correct the acoustic characteristics in cars and adjust the frequency characteristics by programming. Correction also requires careful consideration, which is why car stereos are now being equipped with graphic equalizers.

This graphical equalizer (hereinafter referred to as GEQ) divides the frequency band of an audio signal into multiple frequency bands, or channels, and changes the frequency characteristics for each channel, making it possible to arbitrarily change the frequency characteristics across all bands. Generally, a combination of a simulated inductor using an operational amplifier and a bridge amplifier is used.
The above requirements can be met by providing a GEQ in a car stereo.

By the way, conventional GEQs are equipped with a large number of variable resistors or switches for adjustment, corresponding to the channels mentioned above, so operating them requires considerable skill and is still quite troublesome. This has become a cumbersome operation.

Therefore, not only does it put a considerable psychological burden on the user to repeatedly operate the GEQ when changing programs, but it also puts a heavy burden on the user, especially when used as an in-vehicle device such as a car stereo. There was a risk that it would become extremely undesirable from a safety standpoint.

It is an object of the present invention to be able to easily set any frequency characteristic, to store data corresponding to this frequency characteristic in advance in memory, and to read out and set the stored frequency characteristic simply by operating a preset key. It is an object of the present invention to provide an equalizer device that can be used in a 2-speaker system and a 4-speaker system, and can also be applied to a 2-speaker system and a 4-speaker system.

To achieve this object, the equalizer device of the present invention includes a signal transmission circuit whose frequency characteristics over almost the entire audio signal frequency band can be controlled by electrical control data, and control data for the signal transmission circuit. a plurality of push button keys respectively provided for each frequency band for raising and lowering the level of each divided frequency band; and a preset data input means for presetting the data. , a memory means capable of presetting and reading the data, a display means displaying the frequency characteristics provided by the signal transmission circuit by indicating a setting level for each frequency band, and It is provided with a switching means for switching between outputting the output as it is or outputting the output in multiple frequency divisions, and a display for displaying the switching state of the switching means, and when the output is divided into a plurality of parts by the switching means, Each of the push button keys is characterized in that it can control the level of any one of a plurality of divided outputs.

Embodiments of the equalizer device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a system block diagram showing an embodiment of the present invention, in which 1L and 1R are amplifiers, 2 is a control circuit, 3 is a reactance circuit, 4 is a data input device that also serves as a frequency display, 5 is a memory, and 6 is a system block diagram showing an embodiment of the present invention. is a preset data input device, 7 is a display device, and 8 is a preset data input device.
L, 8R are low pass filters (LPE), 9L, 9
R is a power amplifier, 10L, 10R are rear speakers, 11L, 11R are high pass filters (HPF), 12L, 12R are power amplifiers, 1
3L, 13R are front (front) speakers, 14
L and 14R are 2-speaker system-4-speaker system changeover switches.

Audio signals from a car stereo tape deck, radio, etc. are supplied to the left channel and right channel inputs, and are given arbitrary frequency characteristics and output through amplifiers 1L and 1R that make up the GEQ's transmission circuit.

Suppose now that the changeover switches 14L and 14R have been switched to the contact a side. Then, the signals appearing at the outputs of the amplifiers 1L and 1R are applied as they are to the power amplifiers 9L and 9R, and are power amplified and supplied to the speakers 10L and 10R.
Normal two-channel sound reproduction is performed.

Further, when the changeover switches 14L and 14R are switched to the contact b side, each amplifier 1L and 1
The signal from R is applied to power amplifiers 9L and 9R via LPF8L and 8R, and is also applied to HPF1
Power amplifier 12L, 12R via 1L, 11R
is also applied.

Therefore, among the audio signals supplied to the inputs from the rear speakers 10L and 10R, LPF8L and
The low frequency part that passed through 8R is reproduced, and HPF11L, 11 is output from front speakers 13L, 13R.
The high frequency part that passed through R will be reproduced,
Sound reproduction will be performed giving a pseudo four channel effect.

Now, the amplifier 1L that constitutes the transmission circuit of GEQ,
A reactance circuit 3 consisting of a large number of reactance elements is supplied to 1R via a control circuit 2, and the amount of passage of the entire audio signal band is controlled for each of the many channels, so that arbitrary frequency characteristics can be given. There is. This control circuit 2 consists of a plurality of sets of resistance circuit networks and electronic switches, and the electronic switches are selectively controlled by control data given from the data input device 4, and any reactance element in the reactance circuit 3 is controlled to a predetermined value. It is connected to amplifiers 1L and 1R through a resistor network, and operates to provide arbitrary frequency characteristics. At this time, as mentioned above, the amplifiers 1L and 1R
A bridge amplifier using an operational amplifier or the like is mainly used, and a simulated inductor also using an operational amplifier is mainly used as the reactance element of the reactance circuit 3.

The data input device 4 is designed to obtain data that gives the characteristics of an arbitrary frequency section using a plurality of multi-contact switches, and normally there are five switches for up and down for each channel. It consists of push button keys and lamps such as LEDs, and by operating each key, data that provides the necessary frequency characteristics is generated. The preset data input device 6 is a keyboard switch consisting of a memory key and several preset keys (numeric keys).When one of the memory keys and one of the preset keys is pressed at the same time, a write signal WE is generated and the preset key is pressed. The data given from the data input device 4 at that time is stored at the corresponding address in the memory 5, and when only the preset key is pressed next, the data is read from that address in the memory 5.

Therefore, if the push button key of the data input device 4 is operated and the associated multi-contact switch is moved, the data that was latched until then will be erased and the data generated by the push button key of the data input device 4 will be generated instead. The control data is latched and
It is then given to the control circuit 2.

Further, when a preset key of the preset data input device 6 is pressed, the control data recorded at the corresponding address is read out from the memory 5, and at the same time, a display signal is given to the data input device 4, and the control data is read out from the memory 5. data input signals are now given to the control circuit 2.
At this time, the data input device 4 simultaneously displays a frequency indicating the content of the data input signal applied to the control circuit 2.

Therefore, by operating the data input device 4, for example, the required frequency characteristics can be set using the five push buttons for up and down for each channel, just as in the conventional GEQ. Furthermore, by simply selecting a preset key on the preset data input device 6,
By selecting one of the data preset in advance using the data input device 4, the corresponding frequency characteristic is given with a single touch, and
The frequency characteristics given by GEQ can be visually observed.

In addition, the display device 7 includes changeover switches 14L, 14
The display device 7 can be incorporated into the data input device 4 as shown in FIG. 4, and one embodiment is shown in FIG. 2. ing. In the figure, 7
7b and 7e are red light emitting elements, and 7c and 7d are green light emitting elements. The light emitting elements 7b to 7e may be of any type, such as LEDs or liquid crystals of corresponding colors. These light emitting elements 7b-7
FIG. 3 shows an embodiment of the drive circuit for the drive circuit. In the figure, 14-1 is a switch that operates in conjunction with changeover switches 14L and 14R.

Therefore, when the car stereo is switched to the two-speaker system, the red light-emitting element 7b and the green light-emitting element 7c are lit, but when the car stereo is switched to the four-speaker system, all the light-emitting elements 7b to 7 are lit.
e lights up.

FIG. 4 shows an embodiment of the operation panel surface of the equalizer device according to the present invention, in which 4a to 4e are push button keys for increasing the left channel frequency characteristics, 4a' to 4e' are push button keys for decreasing the left channel frequency characteristics, and 4f.
~4j are push button keys for increasing the right channel frequency characteristics, 4f'~4j' are push button keys for decreasing the right channel frequency characteristics, 4L is a red display frame, 4L' is a green display frame, 4R is a green display frame, 4R ' is a red display frame, 4k is a plurality of display lamps corresponding to each channel, 6a is a memory key, and 6b is a plurality of preset keys.

Here, the push button keys 4a to 4j and 4a' to 4j' are input push button keys of the data input device 4 in FIG.
By pressing buttons a to 4j and 4a' to 4j', the frequency characteristics are moved up or down one step at a time, and the set position of the frequency characteristic is displayed. Also, memory key 6a,
Preset key 6b is a keyboard switch provided on the preset data input device.

If the operation of the car stereo is now switched to a two-speaker system, only the red light emitting element 7b and the green light emitting element 7c are lit.

Therefore, at this time, the operation keys 4a to 4e, 4a' to 4 surrounded by the red display frame 4L
e' corresponds to all of the frequency characteristics of the left channel, and operation keys 4f to 4j and 4f' to 4j' surrounded by the green display frame 4R correspond to all of the frequency characteristics of the right channel. This can be immediately recognized by the operator.

Further, when the operation of the car stereo has been switched to the four-speaker system, in addition to the red and green light emitting elements 7b and 7c, the green light emitting element 7d and the red light emitting element 7e are also turned on.

Therefore, at this time, the red display frame 4L is indicated by lighting the red light emitting element 7b, and the display frame 4L is indicated by lighting the green light emitting element 7d.
The push button keys 4d, 4d', 4e, and 4e' present in the area surrounded by the green display frame 4L' are instructed to correspond to the signal reproduced from the front speakers. . Similarly, the green display frame 4R is designated by lighting the green light emitting element 7c, and the display frame 4R is designated by lighting the red light emitting element 7e.
The red display frame 4L' in R is the push button key 4i, 4i', 4 corresponding to the front speaker of the right channel.
j, 4j'.

Therefore, at this time, the characteristics of the rear speakers in each left and right channel are determined by the push button keys 4a to 4.
c, 4a' to 4c', 4f to 4h, and 4f' to 4h', the characteristics of the front speakers are determined by the push button keys 4d,
4d', 4e, 4e' and 4i, 4i', 4j, 4j' accurately indicate to the operator what adjustments to make, respectively.

On the other hand, as described above, when any one of the preset keys 6b is pressed, the corresponding address data is given to the memory 5, and control data is written to or read from that address. is input to the data input device 4 as display data, and the display data is displayed by the lighting position of the display lamp 4k. Therefore, when the control data from the data input device 4 is written into the memory 5 by the preset key 6b of the preset data input device 6, and when the control data is read from the memory 5 and written into the data input device 4, When the data is transmitted, the display lamps 4k corresponding to the operated preset keys 6b are lit until the data input device 4 or preset data input device 6 is operated again, and the lighting position indicates the current state.
The state of the frequency characteristics given by GEQ is displayed, allowing you to perform operations such as presetting control data accurately.

In addition, in the above embodiment, the red light emitting element 7b
Red instruction frames 4L and 4R' are provided corresponding to and 7e, and green instruction frames 4R and 4L' are provided corresponding to green light emitting elements 7c and 7d, respectively, and operation instructions are given by the correspondence of these colors. However, the embodiments of the present invention are not limited to this, and the light emitting elements 7b to 7e and the indicator frames 4L, 4L', 4R, 4
The color, position, shape, etc. of R' can be determined arbitrarily; for example, the colors of the light emitting elements 7b to 7e may all be different, and the colors of the indicator frame 4L, etc. may also be all different correspondingly. Good too.

As explained above, according to the present invention, an equalizer device includes a signal transmission circuit whose frequency characteristics over almost the entire audio signal frequency band can be controlled by electrical control data, and a signal transmission circuit for controlling the signal transmission circuit. a plurality of pushbutton keys provided for each frequency band to raise and lower the level of each divided frequency band, and a preset data input for presetting the data. means, memory means capable of presetting and reading the data, display means for displaying the frequency characteristics provided by the signal transmission circuit by indicating the set level for each frequency band, and the signal transfer means. A switching means for switching between outputting the output of the circuit as it is or dividing the output into multiple frequencies, and a display for displaying the switching state of the switching means, and when the output is divided into a plurality of parts by the switching means, the plurality of frequencies are output. Each of the push-button keys can control the level of any one of the divided multiple outputs, so you can easily set any frequency characteristic using the multiple push-button keys, and once you have set the desired frequency characteristics. Frequency characteristics can be stored in memory and recalled with a single touch when necessary, and the set frequency characteristics can be visually confirmed.Furthermore, when switching between 2-speaker system and 4-speaker system, each system can be easily identified. In addition, in the 2-speaker system, multiple push buttons each adjust the frequency characteristics of the audio signals output from the rear speakers, while in the 4-speaker system, the frequency characteristics of each audio signal output from the front and rear speakers can be adjusted. It is possible to provide an equalizer device that can be adjusted to have separate characteristics for each, and that can be used to switch between a two-speaker system and a four-speaker system without increasing the number of push buttons or the like.

[Brief explanation of drawings]

The drawings all relate to the present invention; FIG. 1 is a block diagram showing an embodiment of an equalizer device, FIG. 2 is a front view showing an embodiment of a display device, and FIG. 3 is a diagram showing an example of a drive circuit for the display device. FIG. 4 is a front view showing an embodiment of the equalizer device according to the present invention. 1L, 1R, 9L, 9R, 12L, 12R: Amplifier, 2: Control circuit, 4: Data input device, 5:
Memory, 6: Preset data input device, 7: Display device, 8L, 8R: Low pass filter, 11
L, 11R: High pass filter, 14L, 14
R: Changeover switch, 4a to 4J, 4a' to 4j': Push button key, 4k: Display lamp, 6a: Memory key,
6b: Preset key.

Claims (1)

[Claims] 1. A signal transmission circuit whose frequency characteristics over almost the entire audio signal frequency band can be controlled by electrical control data, means for generating control data for the signal transmission circuit, and levels for each divided frequency band. a plurality of push button keys respectively provided for each frequency band for raising and lowering the data; preset data input means for presetting the data; and memory means capable of presetting and reading the data. ,
A display means for displaying the frequency characteristics given by the signal transmission circuit by indicating a setting level for each frequency band, and a display means for displaying the frequency characteristics given by the signal transmission circuit by indicating a setting level for each frequency band, and a display means for indicating whether the output of the signal transmission circuit is to be output as is or to be divided into multiple frequencies and output. It is provided with a switching means for switching and a display for displaying the switching state of the switching means, and when the output is divided into a plurality of outputs by the switching means, each of the plurality of push button keys can be used to select one of the plurality of divided outputs. An equalizer device characterized in that two levels can be controlled.