JP2005198356A - Display controller for displaying gain setting value by hue - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display controller that enables a user to identify a gain setting value by having only to view a displayed color at a glance and can optionally set a range of the gain setting value for varying the hue of a hue variable display device. <P>SOLUTION: An electronic volume 1 receives a music signal, adjusts the gain by a sound volume setting level and outputs to an amplifier 2. A CPU 4a outputs the sound volume setting level to the electronic volume 1 depending on an output of a rotary encoder 5. The CPU 4a generates a hue control signal to change the hue of three color light emitting diodes 10 depending on the sound volume setting level by referring a ROM table 4b. The CPU 4a captures the sound volume setting level when an upper limit setting switch 8 is operated and stores it as an upper limit x<SB>high</SB>of the sound volume setting level to change the hue between 'purple' and 'red'. The hue can stepwise be varies from the sound volume setting level of 0 to the upper limit x<SB>high</SB>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a display control device for displaying a gain setting value such as a sound volume setting level by hue in an amplifier circuit such as an audio amplifier.

In recent years, in an audio amplifier circuit such as an audio amplifier, an electronic volume is often used and a volume setting level is adjusted by voltage control. Since there is no mechanical sliding part, the electronic volume has advantages such as no secular change and easy remote control.
However, in the electronic volume, for example, a rotary encoder that gives a rotation amount and a rotation direction is used as a setting operator. Therefore, the volume setting level is not known from the rotation angle itself. Even when an up button or a down button is used as an operator, the volume setting level cannot be determined only from the number of pressing operations. Therefore, the volume setting level cannot be determined unless it is judged by looking at the number display device or by actually hearing the sound.

For example, when the power of the audio amplifier is turned on, the electronic volume retains the volume setting level when the power is last turned off. However, some users turn off the power after reducing the volume setting level to the minimum, while other users turn off the power while listening at the high volume setting level. Since this is due to the habits and habits of each user, it cannot be generally stated.
Therefore, if the current volume setting level is not known after the power is turned on and before the music signal is played, there is a risk that playback will be inadvertently started at a high volume.

In order to display the volume setting level, the attenuation level is displayed numerically on the panel of the audio amplifier with a light emitting diode (LED), a fluorescent display tube, or a liquid crystal display (LCD). May be displayed. In this case, it can be visually recognized if it is close, but since the display space is small, it is difficult to discriminate from a little away.
On the other hand, in the mechanical volume, although the setting level is known by the rotation angle of a small sign provided on the volume knob, the sign is difficult to distinguish from a remote place, and the numeric display on the panel is also difficult to distinguish.
Thus, recently, there has been a demand for a display form that improves the point where the volume setting level is difficult for the user to understand and makes it possible to understand the volume setting level at a glance.

  The present invention has been made in view of the above-described circumstances, and it is possible to identify a gain setting value such as a volume setting level only by looking at a display hue of a variable hue display, and change a hue of the variable hue display. An object of the present invention is to provide a display control device for displaying a gain setting value by hue, in which the range of the gain setting value to be set can be arbitrarily set.

The present invention according to claim 1, in the display control device for displaying the gain setting value by hue, has a display hue control means, an input upper limit value setting means, and a color table storage means, The color table storage means stores red, green, and blue data for changing the hue of the hue variable display corresponding to the color table number, and the display hue control means includes a variable gain control device. A gain setting value is input, the color table number is determined according to the gain setting value and a predetermined upper limit value, and the red, green and blue colors are stored from the color table storage means using the determined color table number. When the gain setting value is within the predetermined upper limit value or less by reading the data, the hue of the variable hue display is set to the predetermined first hue and the predetermined hue according to the magnitude of the gain setting value. of The hue of the variable hue display is changed to the predetermined second hue when the gain setting value exceeds the predetermined upper limit value. The input upper limit value setting means arbitrarily sets the predetermined upper limit value of the gain setting value by a user's operation.
Therefore, the user can arbitrarily set an upper limit value of the gain setting value that changes the hue of the variable hue display between the predetermined first hue and the predetermined second hue.
In practice, the variable gain control device is often used with a gain setting value smaller than the maximum gain setting value. Even in such a case, if the user sets the upper limit value in actual use of the gain setting value as the predetermined upper limit value using the input upper limit value setting means, the current gain setting value becomes the upper limit in actual use. The range up to the value can be known at a glance by changing the hue of the variable hue display between the predetermined first hue and the predetermined second hue.
Further, when the current gain setting value is increased, the upper limit value in actual use can be known by the hue of the hue variable display unit becoming the predetermined second hue.
For example, when the input upper limit value setting unit detects that the input upper limit setting operator has been operated, the input upper limit value setting unit inputs the gain setting value of the variable gain control device and holds this as a predetermined upper limit value. If so, it can be easily realized.

According to a second aspect of the present invention, a display control device for displaying a gain setting value by hue includes display hue control means and input upper limit value setting means, and the display hue control means includes variable gain control. When a gain setting value is input from the apparatus and the gain setting value is in a range equal to or less than a predetermined upper limit value, the hue of the variable hue display device is changed to a predetermined first hue according to the magnitude of the gain setting value. A hue control signal that changes between a predetermined second hue and sets the hue of the variable hue display to the predetermined second hue when the gain setting value exceeds the predetermined upper limit value. The input upper limit value setting means outputs the gain setting value input from the variable gain control device when it is detected that the input upper limit setting operator has been operated by a user's operation. Of the gain setting value It is intended to arbitrarily set by holding the serial predetermined upper limit value.
3. The display control apparatus for displaying a gain setting value by hue according to claim 1 or 2, wherein the predetermined first hue is purple or blue, and the predetermined second hue is red. it can. Therefore, since the hue change matches human safety and sensitivity to danger, the gain setting value can be intuitively recognized. In particular, if the predetermined first hue is purple, the hue display capability of the variable hue display can be utilized to the maximum.

According to the present invention, the user can identify the gain setting value such as the sound volume setting level only by looking at the display color of the variable hue display.
In addition, there is an effect that the user can arbitrarily set the range of the gain setting value that changes the hue of the hue variable display. As a result, the user can also know from the hue of the hue variable display that the current gain setting value is in the practical use range.
Since the color display area of the variable hue display may be small, the display space can be relatively small.
Changing the hue of the variable hue display from “purple” or “blue” to “red” according to the magnitude of the gain setting value will result in a hue change that matches human safety and sensitivity to danger. Therefore, the user can intuitively recognize the gain setting value.
In particular, if the color is changed from “purple”, the hue display capability of the hue variable display can be utilized to the maximum.
Even when the gain setting value is displayed numerically on a color fluorescent display tube, a color liquid crystal display device, etc., the user can set the gain from a remote location by using the hue variable display and the display control device of the present invention in combination. The value can be visually recognized.

FIG. 1 is a block diagram of a display control apparatus for displaying a gain setting value by hue according to the present invention when applied to an audio amplifier using an electronic volume.
In the figure, reference numeral 1 denotes an electronic volume, which inputs an audio signal such as a music signal, variably adjusts the volume setting level, in other words, the attenuation of the electronic volume, and outputs it to the amplifier 2. The amplifier 2 amplifies the output signal of the electronic volume and sounds a speaker. The adjustment of the attenuation is generally a gain adjustment. In the illustrated example, the overall gain of the audio amplifier including the amplifier 2 is adjusted.

Reference numeral 4 denotes a one-chip microcomputer. The specific internal configuration is not shown, and only a CPU (Central Processing Unit) 4a and a ROM (Read Only Memory) table 4b are shown.
Reference numeral 5 denotes a rotary encoder which is rotated by a volume knob 5a and outputs a rotation direction and a rotation amount to the CPU 4a. The CPU 4a holds the current value of the volume setting level, and updates the current value by increasing / decreasing it according to the rotation amount. The direction of increase / decrease is determined by the rotation direction of the rotary encoder 5.

6 is a remote controller, and 7 is a light receiving unit. The remote controller 6 transmits a control signal output by appropriately pressing a plurality of buttons by the user to the light receiving unit 7 using infrared rays.
The light receiving unit 7 outputs this control signal to the CPU 4a. The remote controller 6 can execute the same function as the rotary encoder 5 described above by pressing a button. Moreover, the function of the upper limit setting switch 8 described later can also be executed.
8 is an upper limit setting switch, and 9 is a PWM (pulse width modulation) control LED driver circuit.
Reference numeral 10 denotes a three-color light emitting diode, in which three LED chips of red, green and blue are enclosed in one package. 11 _R , 11 _G , 11 _B are load current limiting resistors for the LED chips of the three-color light emitting diode.

The CPU 4 a holds the volume setting level according to the output of the rotary encoder 5 and outputs it to the electronic volume 1. At the same time, a hue control signal for changing the hue of the three-color light emitting diode 10 according to the volume setting level is created with reference to the ROM table 4 b and output to the PWM control LED driver circuit 9.
The PWM control LED driver circuit 9 uses the drive current for each of the red, green, and blue LED chips of the three-color light emitting diode 10 as a PWM control signal, and the on period for one period of the PWM control signal in accordance with the hue control signal described above. By controlling the ratio, the luminance ratio of each LED chip is controlled to control the hue of the mixed color.

Therefore, the CPU 4a controls the volume setting level of the electronic volume 1, and controls the hue of the three-color light emitting diode according to the volume setting level.
When the range in which the hue is changed is determined between the predetermined first hue and the predetermined second hue, the first and second hues can be arbitrarily determined.
However, in order to adapt to human sense and easily recognize intuitively, select “purple” or “blue” as the first hue when the volume setting level is low, and increase the volume when the volume level is high. Since there is a risk of sounding, it is preferable to select “red” as the second hue, select “green” for the normal volume level, and “yellow” for the volume setting level that requires a little attention. Thus, since the selection of the hue matches the human safety and the sensitivity to danger, the volume setting level can be intuitively recognized.
In the following description, a case where the first hue is “purple” and the second hue is “red” will be described.

Here, the hue display has a problem in actual use.
Taking an electronic volume as an example, attenuation amounts 0 dB to -79 dB, -∞ dB (mute) are changed in 66 steps. In the range where the amount of attenuation is large, it is partially changed by several dB in one step, but in most other regions, it is changed by 1 dB in one step.
Assume that the hues from “purple” to “red” are allocated in proportion to the maximum number of steps and in proportion to the number of steps from −∞ dB. However, if the electronic volume 1 is used up to an attenuation of 0 dB (the maximum value of the audio amplifier gain), the hue becomes “red”, which is dangerous. However, there are almost no such usage patterns.
Therefore, it cannot be accurately known from the hue at that time that the current volume setting level is a dangerous upper limit value in actual use.

Another problem is that the hue display capability cannot be fully utilized. That is, the practically used range (practical use range) in the audio amplifier is about −32 dB to −18 dB, and is set to −∞ dB when the volume is reduced.
In the exemplified electronic volume, the practical use range is about 50% to 70% of the total number of steps as the number of steps from −∞. Therefore, if the 0 to 12-level color table number y, which will be described later with reference to FIG. 2, is used, it is “green” to “yellow-orange” in the practical use range, and “blue” only when the volume is reduced. ”And“ purple ”.
On the other hand, in the case of using an analog volume (mechanical volume) whose resistance value changes with an A curve characteristic, the practical use range described above is 20% to 40% of the maximum rotation angle. Therefore, if the hue from “purple” to “red” is made to correspond to the maximum rotation angle and the hue is allocated in proportion to the rotation angle, only the vicinity of “blue” is used in the actual usage range. become.

Therefore, the input upper limit value of the volume setting level is set so that the three-color light emitting diode 10 can be known by the predetermined second hue that the volume setting level has reached the upper limit value in actual use. To do.
The user rotates the volume knob 5a to set the current value of the volume setting level to the volume setting level that is the upper limit value in actual use, and operates the upper limit value setting switch 8 at this time. The CPU 4a takes in the current value of the volume setting level when the upper limit value setting switch 8 is operated, and holds it as the upper limit value of the volume setting level when changing the hue between “purple” and “red”. To do.

FIG. 2 is an explanatory diagram of a first example showing the relationship between the volume setting level and the hue of the three-color light emitting diode 10.
In the figure, the horizontal axis represents the volume setting level x, where the minimum volume setting level is 0, the maximum volume setting level is x _max , and the upper limit value of the volume setting level for changing the hue is x _high . As the volume setting level, the gain is indicated by a linear scale.
Instead of this, the gain (attenuation amount) may be expressed as a dB value on a logarithmic scale. At this time, the minimum volume setting level 0 corresponds to −∞ dB in the illustrated electronic volume, and the adjacent attenuation amount is −79 dB.
The vertical axis indicates the hue of the three-color light emitting diode 10 by the color table number y (0 ≦ y ≦ n). In the illustrated example, a case where n = 12 is shown.

In the example shown in the figure, when y = 12, “red” is set, and when the hue is temporarily realized with monochromatic light, the hue is gradually changed to the short wavelength side according to the wavelength of the monochromatic light, and y = 0. The time is "purple". In this figure, the hue is expressed in a pseudo manner using hatching.
Further, corresponding to y, numerical values representing output values of R (red), G (green), and B (blue) are shown. These numerical values are stored in the ROM table 4b shown in FIG. 1, and are read out by the CPU 4a in accordance with the current volume setting level and the upper limit value x _high for changing the hue, and output to the PWM control LED driver circuit 9. To do.
Note that the output values of R, G, and B for each color table number y stored in the ROM table 4b may be different depending on whether the volume setting level is expressed by a linear scale or a logarithmic scale.

In the figure, when the volume setting level x is gradually increased from 0, the color table number y changes from y = 0 “purple” to a staircase in the volume setting level range indicated by (1) up to x _high. y = 12 “red”.
In the figure, black circles include the value of x at this time, and white circles indicate that the value of x at this time is not included.
In the volume setting level range indicated by (2) where the volume setting level x is from x _high to x _max , y = 12 “red” is fixed and the hue does not change.

The user sets an upper limit value x _high of the volume setting level in advance using the upper limit value setting switch 8. When the user increases the volume setting level, the hue changes from “purple”, and when the user reaches the upper limit value of the normally used volume setting level, the hue changes to “red”.
As a result, the volume setting level is in the range of the upper limit value x _high or less, and the hue of the three-color light emitting diode 10 changes between the first hue “purple” and the second hue “red”. You can know more.
Further, it is possible to know that the upper limit value x _high of the volume setting level normally used by the user is reached by the second hue “red”.

The relationship between the volume setting level x and the color table number y described above can be expressed by a mathematical expression as follows. This equation may be used when the CPU 4a performs an operation by executing a program.
y = floor {(n / x _high ) · x} (0 ≦ x ≦ x _high )
y = n (x _high <x ≦ _xmax )
Here, “floor” is a function that truncates the numbers after the decimal point in {}.
There is also a method of directly controlling the RGB output values by the value of x _high . However, as described above, by determining the color table number y according to the volume setting level x, the value of the upper limit value x _high can be obtained without changing the output values of R, G, B in each color table number y. The relationship between the volume setting level x and the hue can be changed according to.

Since the change in hue is not continuous but stepwise, the method of providing steps up to the upper limit value x _high of the volume setting level for changing the hue is not unique and is not limited to the case shown in the figure.
In FIG. 2, in the range of (1), the volume setting level is divided into n = 12 equally spaced sections, the first section is set to y = 0, the twelfth section is set to y = 11, and the upper limit value x _High is changed to y = 12.
Instead, in the range of (1), the volume setting level is divided into n + 1 = 13 sections. In the first section and the thirteenth section, the width of the volume setting level is the other half, and the first section The section may be y = 0 and the thirteenth section may be y = 12.
Alternatively, in the range (1), the volume setting level may be divided into n + 1 = 13 equally spaced sections, the first section may be y = 0, and the thirteenth section may be y = 12.

In the above description, only the upper limit value x _high of the volume setting level for changing the hue can be arbitrarily set by the user. On the other hand, the lower limit value x _low of the volume setting level for changing the hue of the three-color light emitting diode may be arbitrarily set.
FIG. 3 is an explanatory diagram of a second example showing the relationship between the sound volume setting level and the hue of the three-color light emitting diode.
In the figure, the horizontal axis is the same volume setting level x as in FIG. 2, the minimum volume setting level is 0, the maximum volume setting level is x _max , the lower limit value of the volume setting level to change the hue is x _low , and the hue is changed Let x _{high be} the upper limit of the volume setting level to be activated.
The vertical axis is the same as in FIG. 2, and the hue of the three-color light emitting diode 10 is indicated by a color table number y (0 ≦ y ≦ n). Although the output values of the hues R, G, and B corresponding to y are not shown, they may be determined according to the total number of colors to be displayed. When n = 12, the numerical values shown in FIG. Use it.

In the figure, the color table number is fixed to y = 0 “purple” and the hue does not change in the volume setting level range indicated by (3) where the volume setting level x is less than the lower limit value x _low .
When the volume setting level x exceeds the lower limit value x _low and enters the range of the volume setting level shown in (1), the color table number y is stepped from y = 0 “purple” when it is less than the lower limit value x _low. It changes stepwise until y = n “red” at the upper limit x _high .
In the range of the volume setting level indicated by (2) where the volume setting level x exceeds the upper limit value x _high and is not more than the maximum value x _max , y = 12 “red” is fixed and the hue does not change.

The user captures and holds the upper limit value x _high using the upper limit value setting switch 8 shown in FIG. 1, and similarly uses a lower limit value setting switch (not shown) to lower the volume setting level lower limit value x _low. Capture and hold.
If the volume setting level is lowered within the normal use range of the user, the hue will turn “purple” if the lower limit of the normal volume setting level is exceeded, and if the volume setting level is raised, it will be used normally. When the upper limit of the volume setting level is reached, the hue becomes “red”.
As a result, the volume setting level is in the range of the lower limit value x _low or more and the upper limit value x _high or less, indicating that the hue of the three-color light emitting diode 10 is the first hue “purple” and the second hue “red”. You can know by changing between.
In addition, the user can know that the lower limit value x _low of the volume setting level normally used by the user has become the first hue “purple”, and has reached the upper limit value x _high of the volume setting level. Can be known by becoming the second hue “red”.

The relationship between the volume setting level x and the color table number y described above can be expressed by mathematical formulas as follows, and this formula is used when the CPU 4a executes the program.
y = 0 (0 ≦ x <x _low )
y = floor {(n−1) / (x _high −x _low ) · (x−x _low )} + 1
(X _low ≤ x ≤ x _high )
y = n (x _high <x ≦ x _max )

Also in the second example, since the hue change is not continuous but stepwise, the way of providing the steps from the lower limit value x _low to the upper limit value x _high of the volume setting level for changing the hue is unambiguous. However, the present invention is not limited to the illustrated case.
In FIG. 3, in the range of (1), the volume setting level is divided into n equally spaced sections, the first section is set to y = 1, the nth section is set to y = (n−1), and the upper limit is set. The value x _high is changed to y = n.
Instead, in the range of (1), the volume setting level is divided into (n + 1) sections. In the first section and the (n + 1) section, the width of the volume setting level is the other half, The first interval may be y = 0, and the (n + 1) th interval may be y = n.
Alternatively, in the range (1), the sound volume setting level may be divided into (n + 1) equally spaced sections, and the first section may be y = 0 and the (n + 1) th section may be y = n.

FIG. 4 is a block diagram when the display control device for displaying the gain setting value according to the hue of the present invention is applied to an audio amplifier using a mechanical volume.
In the figure, parts similar to those in FIG. Reference numeral 21 denotes a mechanical volume, which is a variable resistor having a sliding contact. Reference numeral 22 also denotes a mechanical volume, and the mechanical volume 21 and the mechanical volume 22 are double volumes that rotate in conjunction with each other. The one-chip microcomputer 23 includes a PWM control signal generator 23c in addition to the CPU 23a and the ROM table 23b. This is realized by the one-chip microcomputer 23 executing the program with the function of the PWM control LED driver circuit 9 shown in FIG. 25 _R , 25 _G and 25 _B are drive transistors for supplying drive power to the LED chips of the three-color light emitting diode 10. Each base electrode receives a drive signal in which the output values of R, G, B are controlled from the PWM control signal generator 23c via the base current limiting resistors 24 _R , 24 _G , 24 _B , and each collector electrode Each LED chip of the three-color light-emitting diode 10 is connected to.

The volume setting level of the mechanical volume 21 cannot be output to the one-chip microcomputer 4 as it is. Therefore, the power supply voltage VCC is applied to the mechanical volume 22 interlocked with the mechanical volume 21, and a divided voltage corresponding to the rotation angle is obtained from the sliding contact. This divided voltage becomes a voltage value proportional to the volume setting level, and is output to the A / D conversion input terminal of the one-chip microcomputer 23. The CPU 23a performs A / D conversion on this voltage value, and processes it, for example, as a linear scale volume setting level.
The method for setting the upper limit value is the same as that shown in FIG.

The mechanical volumes 21 and 22 have various relationships between the rotation angle and the resistance value depending on the resistance value curve. Therefore, for example, when the hue is to be changed corresponding to the rotation angle while using the mechanical volumes 21 and 22 having the A curve characteristic, the R value for each color table number y stored in the ROM table 4b. , G, B output values need to be changed.
Alternatively, if the mechanical volume 21 has an A curve characteristic and the mechanical volume 22 has a B curve characteristic (linear characteristic), a divided voltage proportional to the rotation angle can be obtained, so that the ROM table 4b is not particularly changed. The color table number y corresponding to the rotation angle can be obtained.

In the above description, the one-chip microcomputers 4 and 23 are used, but a general-purpose CPU may be used.
In this case, a CPU, ROM, and RAM are connected to the bus line, and the CPU executes a program stored in the ROM using the RAM as a working area. The table storing the output values of the hues R, G, and B corresponding to the color table number y may be stored in a non-rewritable ROM, but if stored in the flash memory, the color table is stored. It becomes rewritable.

Next, a specific example in which the volume knob 5a and the three-color light emitting diode 10 are arranged on the front panel of the audio amplifier will be described with reference to FIGS.
Although an electronic volume is described as a premise, a mechanical volume may be used.
FIG. 5 is a panel layout diagram of a first specific example using one three-color light emitting diode 10.
The package shape of the three-color light emitting diode 10 is various, and is often mounted with a decorative cover and a lens. However, these are omitted here, and the package shape of the three-color light emitting diode 10 is also shown as a circle.

  In FIG. 5A, a three-color light emitting diode 10 is provided adjacent to the volume knob 5a. In FIG. 5B, the three-color light emitting diode 10 is embedded in the volume knob 5a so as to emit light at the center. In either case, when the volume knob 5a is rotated, it changes between “purple” and “red” in the input range of the volume setting level where the hue changes. If the input range is less than the lower limit or exceeds the upper limit, the hue is fixed to “purple” or “red”, respectively, even if the volume setting level itself can be changed.

FIG. 6 is a panel layout diagram of a second specific example using three three-color light emitting diodes 10.
In this specific example, the correspondence between the rotation direction of the volume knob 5a and the increase / decrease direction of the volume setting level is also known.
In the figure, 10 _L is the lower left three-color light emitting diode, 10 _C is the upper center three color light emitting diode, and 10 _R is the lower right three color light emitting diode, which are arranged around the volume knob 4a.

Further, an annular indicator cover 31 is provided so as to cover the three-color light emitting diodes 10 _L , 10 _C and 10 _R. The annular indicator cover 31 has a translucent milky white color, and has a function of scattering adjacent light emission colors by scattering transmitted light.
The current volume setting level is displayed in the hue of the three-color light emitting diode 10 _{C at} the center. Further, the hues of the lower left three-color light emitting diode 10 _L and the lower right three color light emitting diode 10 _R are made to differ in accordance with the rotation direction in which the volume setting level increases. In addition, the current sound volume setting level is roughly indicated for the three-color light emitting diodes 10 _R , 10 _C , and 10 _{R as} a whole.

In FIG. 6A, the three-color light emitting diode 10 _{c in the} upper center is y = 9 “yellow” corresponding to the current volume setting level. Since the rotation direction in which the volume setting level increases is clockwise, the lower left three-color light emitting diode 10 _L has y = 7 “green”, and the lower right three color light emitting diode 10 _R has y = 11 “orange”. It is.
In FIG. 6B, the three-color light emitting diode 10 _{c in the} upper center is y = 7 “green” corresponding to the current volume setting level. The lower left three-color light emitting diode 10 _L has y = 5 “green-blue” and the lower right three-color light emitting diode 10 _R has y = 9 “yellow” in accordance with the rotation direction in which the volume setting level increases.
The annular indicator cover 31 is not always necessary. However, since the light emission colors are mixed between the adjacent three-color light emitting diodes, the hue of the entire annular indicator cover 31 appears to gradually change along the rotation direction in which the volume setting level increases.

FIG. 6C shows a first example of assigning color table numbers to the three-color light emitting diodes.
y _L , y _C and y _R are color table numbers set in the three-color light emitting diodes 10 _L , 10 _C and 10 _R , respectively. Since the relationship between the volume setting level x and y _C is the same as the relationship between the volume setting level x and y in FIGS. 2 and 3, illustration of the relationship with the volume setting level x is omitted.
In FIG. 6 (c), as shown in FIGS. 6 (a) and 6 (b), a difference of 2 is provided for the color table numbers set in the three-color light emitting diodes 10 _L , 10 _C , and 10 _R , respectively. Yes.

FIG. 6D shows a second example of assigning color table numbers to the three-color light emitting diodes.
A difference of 1 is provided for the color table numbers set in the three-color light emitting diodes 10 _L , 10 _C and 10 _R.
However, in both cases of FIG. 6C and FIG. 6D, when the three-color light emitting diode 10 _{c at} the center is y = 0 “purple” or y = 12 “red”, the color table number In some cases, it is not possible to make a difference between y _L , y _C and y _R. However, since all three do not become purple or red, the direction of increase / decrease in the volume setting level is known.
In the case of FIG. 6C, when the three-color light emitting diode 10 _{c at} the center is y _C = 11 and y _C = 1, the color table number difference is 1 or 2.

By the way, in the annular indicator cover 31 shown in FIG. 6, the lower part of the annular indicator cover 41 between the lower left three-color light emitting diode 10 _L and the lower right three color light emitting diode 10 _R becomes an intermediate color. The direction of increase / decrease of the setting level becomes difficult to understand, and it looks strange.
FIG. 7 is a panel layout diagram of third and fourth specific examples using three three-color light emitting diodes and a fifth specific example using five three-color light emitting diodes.
The indicator cover 41 shown in FIG. 7A is obtained by removing the lower part of the annular indicator cover 41 and forming a “Landolt ring” in the visual acuity table.
On the other hand, the indicator cover 42 shown in FIG. 7B is formed by forming light shielding partitions 42a and 42b on the left and right sides of the lower part in the annular indicator cover 41 material. The light shielding partitions 42a and 42b prevent light from being emitted from the lower portion of the indicator cover 42.

FIG. 7C shows the third specific example shown in FIG. 7A in which five three-color light emitting diodes are used to enhance the expressive power of intermediate colors.
10 _CL is the upper left three-color light emitting diode, and in the example shown, the color table number y = 8 “yellowish green”, 10 _CR is the upper right three color light emitting diode, and the color table number y = 10 “yellow orange”. Flashes on.
On the premise of the second specific example shown in FIG. 6 and the fourth specific example shown in FIG. 7B, the number of the three-color light emitting diodes may be five.

Finally, a process for displaying the volume setting level by the hue using the microcomputer will be described.
FIG. 8 is a flowchart illustrating an example of processing for displaying the volume setting level by hue.
This flowchart incorporates display processing by hue into the entire processing loop of the system. However, display processing by hue may be performed by interrupt processing, or may be performed individually by multitask processing.
In S51, it is determined whether or not the upper limit setting switch has been pressed. If it has been pressed, the process proceeds to S52, and if not, the process proceeds to S53.
In S52, the current volume setting level is stored as upper limit value setting data, and the process proceeds to S53.

In S53, it is determined whether or not another operator has been operated. If operated, the process proceeds to S54, and if not, the process proceeds to S55.
In S54, the process according to other operators is performed and the process proceeds to S55. In step S53, the rotation direction and angle of the rotary encoder are detected, the operation of the upper limit setting switch 8 is detected, and the like.
When the sound volume setting level is input by remote control operation, pressing of the up / down button and pressing of the upper limit value setting button are detected.
There are other keys such as a numeric keypad, but the explanation is omitted.
A panel display process is performed in S55, and other processes are performed in S56.

S61 to S66 are detailed flowcharts of the panel display process S55.
In S61, the power light emitting diode that displays power on is turned on. In S62, the current volume setting level is acquired. In S63, the color table number y is calculated based on the current volume setting level and the upper limit value setting data, and the R, G, B data is obtained by referring to the ROM tables 4b and 23b according to the color table number y. take in.
In S64, the red LED chip is driven by the red PWM control according to the R data. In S65, the green LED chip is driven by the green PWM control in accordance with the G data. In S66, according to the B data. Then, the blue LED chip is driven by the blue PWM control, and the process returns to S56.

The flowchart described above starts processing when the power is turned on and repeats the loop until the power is turned off.
In addition, when a user purchases an audio amplifier for the first time and turns on the power, a special registration mode processing flow may be started to perform a range setting operation such as an upper limit setting. That is, when the factory-set upper limit value data is displayed and the user wants to change the upper limit value, the volume setting level is changed by rotating the volume knob to change the upper limit value setting switch 8. To turn on.
Further, a plurality of factory sets may be provided and selected according to the sensitivity of the user. Such factory set selection may be performed during the system steady process flow of FIG.

In the above description, the case where the audio amplifier for inputting a music signal or the like is used for displaying the volume setting level has been described. However, the present invention is not limited to preamplifiers, pre-main amplifiers, and mini-component amplifiers, and can be used to display gain setting values of audio amplifying circuits such as AV (audiovisual) amplifiers, radio receivers, and television receivers.
In addition, it can be generally used to display a gain setting value when an arbitrary input signal is amplified. Attenuation includes the case where an arbitrary input signal is attenuated, as expressed as a negative gain in the decibel expression.

In addition, although the three-color light emitting diode is used as the hue variable display, it may be displayed in a variable hue from red to orange to green by using a two-color light emitting diode of green and red.
In addition, the LED is not limited to one LED chip having different emission colors, but light from each light emitting diode package may be mixed outside to change the hue.
Furthermore, in a color display device such as a color fluorescent display tube, a color liquid crystal display, or a CRT (Cathode Ray Tube), the present invention may be applied when the volume setting level is displayed in hue.

FIG. 3 is a block configuration diagram when the display control device of the present invention is applied to an audio amplifier using an electronic volume. It is explanatory drawing of the 1st example which shows the relationship between a volume setting level and the hue of a 3 color light emitting diode. It is explanatory drawing of the 2nd example which shows the relationship between a volume setting level and the hue of a 3 color light emitting diode. It is a block block diagram at the time of applying the display control apparatus of this invention to the audio amplifier using a mechanical volume. FIG. 3 is a panel layout diagram of a first specific example using one three-color light emitting diode. FIG. 6 is a panel layout diagram of a second specific example using three three-color light emitting diodes. FIG. 6 is a panel layout diagram of second and third specific examples using three three-color light emitting diodes and a fourth specific example using five three-color light emitting diodes. It is a flowchart which shows an example of the process which displays a volume setting level with a hue.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electronic volume, 2 ... Amplifier, 3 ... Speaker, 4, 23 ... One-chip microcomputer, 4a, 23a ... CPU, 4b, 23b ... ROM table, 5 ... Rotary encoder, 5a ... Volume knob, 6 ... Remote controller, 7 ... Light receiving unit, 8 ... Upper limit setting switch, 10, 10 _L , 10 _C , 10 _R , 10 _CL , 10 _CR ... Three-color light emitting diode, 21, 22 ... Mechanical volume, 31 ... Ring indicator cover, 41, 42 ... Indicator cover, 42a, 42b ... Light-shielding partition.

Claims (2)

Display hue control means, input upper limit setting means, color table storage means,
The color table storage means stores red, green and blue data for changing the hue of the hue variable display corresponding to the color table number,
The display hue control means receives a gain setting value from a variable gain control device, determines the color table number according to the gain setting value and a predetermined upper limit value, and uses the determined color table number to determine the color table number. By reading the red, green and blue data from the color table storage means, when the gain setting value is in the range below the predetermined upper limit value, the hue variable display according to the magnitude of the gain setting value The hue of the display unit is changed between a predetermined first hue and a predetermined second hue, and when the gain setting value exceeds the predetermined upper limit value, the hue of the variable hue display unit is changed to the predetermined hue. To output the red, green, and blue data in the second hue of
The input upper limit value setting means arbitrarily sets the predetermined upper limit value of the gain setting value by a user operation.
A display control device for displaying a gain setting value with a hue characterized by the above. Display hue control means, input upper limit value setting means,
The display hue control means receives a gain setting value from a variable gain control device, and when the gain setting value is within a predetermined upper limit value or less, the hue variable display according to the magnitude of the gain setting value When the gain setting value exceeds the predetermined upper limit value, the hue of the variable hue display unit is changed to the predetermined hue. A hue control signal for outputting the second hue;
The input upper limit value setting means determines the gain setting value input from the variable gain control device when the input upper limit setting operator is operated by a user's operation as the predetermined gain setting value. It is arbitrarily set by holding as the upper limit value of
A display control device for displaying a gain setting value with a hue characterized by the above.

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