JPH0413625Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial technical field] This invention relates to a level display device that is used in audio equipment such as tape recorders and displays the levels of multiple frequency bands on the same level indicator. .

[Conventional technology]

As a level display device for an input signal, a digital level display device using a light emitting element such as a fluorescent display tube (FL) or a light emitting diode (LED) as a display segment is often used.

The configuration of such a conventional level display device is
As shown in the figure.

In Figure 1, an input signal such as an audio signal is
After being amplified by amplifier 1, level indicator 3
The signal is supplied to a drive circuit 2 that drives the.

The drive circuit 2 then selectively lights up a plurality of display segments constituting the level indicator 3 in accordance with the level of the supplied input signal to display the level.

The block diagram in Figure 1 is for one channel (L
Although the electric circuit for the R channel is shown, similar electric circuits may be provided for other channels (R channel) as needed.

FIG. 2 is a front view showing an example of the arrangement of a plurality of display segments constituting the level indicator.

In FIG. 2, the level indicator 3 is composed of a plurality of display segments 3A to 3N, such as light emitting diodes.

[The problem that the idea aims to solve]

However, since the conventional level display device is configured as described above, in order to drive the plurality of display segments 3A to 3N constituting the level display 3 according to the level of the entire frequency band of the input signal, the tape When adjusting the recording level of the recorder, the frequency component of the signal driving the maximum level is unknown, making it extremely difficult to adjust the recording level.

This invention was made in order to eliminate the above-mentioned inconvenience, and it is possible to display the entire frequency band level of the input signal and the specific frequency band level of the input signal on the same level display without increasing the number of display segments. A level indicator capable of displaying in two colors is provided.

[Means to solve the problem]

In order to achieve the above object, the level display device according to this invention has a first drive circuit to which an input signal is directly supplied, and a second drive circuit to which an input signal is supplied via a filter circuit having frequency characteristics. a level indicator formed by arranging a plurality of display segments each having two light emitting elements each of which is independently controlled to flash and emit light in a different color; It was constructed with a lighting control circuit that controls the light emitting state of the two light emitting elements of the display segment.

[Effect]

The lighting control circuit of the level display device in this invention uses a display signal that controls the light emitting state of two light emitting elements constituting a plurality of display segments constituting the level display according to the outputs of the first and second drive circuits. output and cause the level indicator to display two different levels.

〔Example〕

Hereinafter, an embodiment of this invention will be described based on the drawings.

FIG. 3 is a block diagram showing the structure of one channel (L channel) of a level display device according to an embodiment of the present invention.

In FIG. 3, 11 is an amplifier that amplifies an input signal such as an audio signal, and 12 is a first drive circuit to which the input signal amplified by the amplifier 11 is supplied. It outputs an output (first drive signal) that turns on and off a plurality of display segments constituting a level indicator 16, which will be described later, according to the level of the signal.

Reference numeral 13 denotes a filter circuit, which allows frequency components of the input signal supplied from the amplifier 11 having a predetermined frequency or higher to pass therethrough.

14 indicates a second drive circuit, and filter circuit 1
turning on a plurality of display segments constituting the level indicator 16 according to the level of the input signal via the
It outputs an output (second drive signal) for turning off.

Reference numeral 15 denotes a lighting control circuit, which selectively lights a plurality of display segments constituting the level indicator 16 in accordance with the supplied first and second drive signals.

Reference numeral 16 denotes a level indicator that displays the level based on the lighting signal from the lighting control circuit 15.

FIG. 4 is an explanatory diagram showing an example of the arrangement of a plurality of display segments constituting a level display device used in the level display device of this invention.

In FIG. 4, 16A to 16N indicate display segments constituting the level indicator 16, respectively.

FIG. 5 is a circuit diagram showing a specific configuration of a single display segment constituting the level display of the level display device of this invention and a lighting control circuit for driving the single display segment.

In FIG. 5, the lighting control circuit 15 is a NAND
Consists of a circuit 15A and a NOT circuit 15B,
The first drive signal of the first drive circuit 12 and the output (display signal) of the NOT circuit 15B are supplied to the two input terminals of the NAND circuit 15A, respectively.
The second drive signal of the second drive circuit 14 is supplied to the input terminal of the circuit 15B.

The single display segment 16A includes a first light emitting diode 16a as a light emitting element that emits green light to display levels of all frequency bands.
and a second light emitting diode 16b as the other light emitting element that emits red light to display the level of the high frequency band, and the first light emitting diode 16
The cathode of a is connected to the NAND circuit 15 via a resistor.
A second light emitting diode 1 is connected to the output end of A.
The cathode of 6b is connected to NOT circuit 15 via a resistor.
It is connected to the output terminal of B.

Next, the operation of the level display device configured as described above will be explained.

First, the input signal amplified by the amplifier 11 is
The first drive circuit 12 turns on the plurality of display segments 16A to 16N constituting the level indicator 16 according to the level of the input signal supplied.
A first drive signal for turning off is output to the lighting control circuit 15.

In addition, since the filter circuit 13 passes only the high frequency band component of the input signal supplied to the second drive circuit 14, the second drive circuit 14 adjusts the level according to the level of the input signal supplied from the filter circuit 13. A second drive signal for turning on and off the plurality of display segments 16A to 16N constituting the display 16 is output to the lighting control circuit 15.

The second drive signal supplied to the lighting control circuit 15 is supplied to the second light emitting diode 16b of the display segment 16A constituting the level indicator 16 via the NOT circuit 15B.
When the display signal of the circuit 15B is at the "L" level, the second light emitting diode 16b lights up in red.

Further, the first drive signal supplied to the lighting control circuit 15 is combined with the display signal of the NOT circuit 15B.
Since it is supplied to the first light emitting diode 16a of the display segment 16A constituting the level indicator 16 via the NAND circuit 15A, the NAND circuit 1
When the 5A display signal is at the "L" level, the first light emitting diode 16a lights up in green.

Therefore, when both the first drive signal and the second drive signal are at "L" level, both the first and second light emitting diodes 16a and 16b are turned off.

When the first drive signal is at "H" level and the second drive signal is at "L" level, only the first light emitting diode 16a lights up in green.

Further, when the first drive signal is at "H" level or "L" level and the second drive signal is at "H" level, only the second light emitting diode 16b lights up in red.

In this way, it is possible to selectively light up the same display segments 16A to 16N in different colors depending on the frequency components of the input signal, and as shown in FIG. 4, an example of the display pattern is a diagonal pattern. The display segment with the mesh pattern is green and the first light emitting diode 16a is lit, and the display segment with the mesh pattern is red and the second light emitting diode 16b is lit.

Note that in the above embodiment, the filter circuit 13
Although the circuit has been described as having a high-pass filter function, it is also possible to use filter circuits with different functions depending on the purpose.

In addition, by providing such a level display device in a tape recorder, providing an oscillator that generates two frequencies inside the tape recorder, and simultaneously recording and playing back signals of two frequencies, it is possible to improve the performance of magnetic tape recording and playback systems. Since the frequency characteristics can be visually known, by applying this method to the equalizer adjustment of a tape recorder, the adjustment can be easily performed.

[Effect of idea]

As described above, according to this invention, the first drive circuit to which an input signal is directly supplied, and the second drive circuit to which an input signal is supplied via a filter circuit having frequency characteristics, blink independently. is controlled, and a level indicator is formed by arranging a plurality of display segments each having two light emitting elements that emit light in different colors; Since it is constructed with a lighting control circuit that controls the light emitting state of the element, the entire frequency band level of the input signal and the specific frequency band level of the input signal can be displayed in two different colors on the same level display without increasing the number of display segments. can be displayed.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of a conventional level display device, Fig. 2 is a front view showing an example of the arrangement of a plurality of display segments constituting the level indicator, and Fig. 3 is an embodiment of the present invention. Block diagram showing the configuration of one channel of the level display device, No. 4
The figure is an explanatory diagram showing an example of the arrangement of a plurality of display segments constituting a level display, and FIG. 5 shows a single display segment constituting the level display and a lighting control circuit that drives the single display segment. FIG. 2 is a circuit diagram showing a specific configuration. 12...First drive circuit, 13...Filter circuit, 14...Second drive circuit, 15...Lighting control circuit, 15A...NAND circuit, 15B...NOT
Circuit, 16...Level indicator, 16A to 16N...
...Display segment, 16a...first light emitting diode, 16b...second light emitting diode.

Claims (1)

[Claims for Utility Model Registration] A first drive circuit to which an input signal is directly supplied;
a second drive circuit to which the input signal is supplied via a filter circuit having frequency characteristics; and a plurality of display segments each having two light emitting elements that are independently controlled to blink and emit light in different colors. A level display device comprising: a level display device comprising: a level display device; and a lighting control circuit that controls the light emission state of the two light emitting elements of the display segment according to the outputs of the first and second drive circuits. .