Level meter displaying method and level meter apparatus

1. A level meter displaying method of displaying a level meter on a display of a device to which a sound signal is input, the level meter comprising a Volume Unit (VU) meter used in an audio equipment, the method comprising:

a displaying step of displaying on the display a scale image obtained according to a single nonlinear function which nonlinearly varies with a signal level of the sound signal, the function being defined for the whole display range of the signal level such that as the signal level becomes lower, a gradient as a rate of change of an indicator angle or indicator position of the level meter increases, the scale image comprising an unequally-spaced scale calibrated at positions varying with a plurality of pre-determined signal levels based on the function;

a converting step of converting the signal level of the sound signal into an indicator angle or indicator position of the level meter according to the function; and

a level image displaying step of displaying on the display a level image corresponding to the indicator angle or indicator position obtained in said converting step,

wherein the function is an nth order function determined by not less than n+1 points of the signal level of the sound signal and the indicator angle or the indicator position, wherein n is a natural number of not less than 2.

2. A level meter displaying method according to claim 1 , comprising a setting step of setting a right angle with respect to a horizontal position of the level meter for an average signal level of the sound signal.

3. A level meter displaying method according to claim 2 , wherein said setting step comprises setting respective predetermined angles with respect to the horizontal position of the level meter for a maximum signal level and a minimum signal level of the sound signal.

4. A level meter displaying method according to claim 3 , wherein the function is a nonlinear function which generates a curve passing through three points consisting of the maximum signal level, the average signal level, and the minimum signal level of the sound signal.

5. A level meter displaying method according to claim 4 , wherein the nonlinear function is a function comprising two straight lines, and a curve which is obtained by interpolating the two straight lines.

6. A level meter apparatus comprising:

a display section that displays a level meter, the level meter comprising a Volume Unit (VU) meter used in an audio equipment;

an input section to which a sound signal is externally input;

a scale display section that displays on said display section a scale image obtained according to a single nonlinear function which nonlinearly varies with a signal level of the sound signal, the function being defined for the whole display range of the signal level such that as the signal level becomes lower, a gradient as a rate of change of an indicator angle or indicator position of the level meter increases, the scale image comprising an unequally-spaced scale calibrated at positions varying with a plurality of pre-determined signal levels based on the function;

a converting section that converts the signal level of the sound signal into an indicator angle or indicator position of the level meter according to the function; and

a level image display section that displays on said display section a level image corresponding to the indicator angle or indicator position obtained by said converting section,

wherein the function is an nth order function determined by not less than n+1 points of the signal level of the sound signal and the indicator angle or the indicator position, wherein n is a natural number of not less than 2.

7. A level meter apparatus according to claim 6 , comprising a setting section that sets a right angle with respect to a horizontal position of the level meter for an average signal level of the sound signal.

8. A level meter apparatus according to claim 7 , wherein said setting section sets setting respective predetermined angles with respect to the horizontal position of the level meter for a maximum signal level and a minimum signal level of the sound signal.

9. A level meter apparatus according to claim 8 , wherein the function is a nonlinear function which generates a curve passing through three points consisting of the maximum signal level, the average signal level, and the minimum signal level of the sound signal.

10. A level meter apparatus according to claim 9 , wherein the nonlinear function is a function comprising two straight lines, and a curve which is obtained by interpolating the two straight lines.

11. A method for converting sound signal inputs into different indicator angles of a level meter that displays a Volume Unit (VU) meter image representative of the converted indicator angles, the method comprising:

setting at least three sound signal levels comprising a minimum signal level, an average signal level and a maximal signal level, each sound signal level corresponding to a unique pre-defined indicator angle to be displayed on the VU meter;

determining a single nonlinear quadratic function based on the three sound signals and their corresponding indicator angles;

displaying on the VU meter a scale panel image obtained according to the function, the scale panel image having unequally-spaced character strings calibrated at positions indicating various signal levels;

receiving a sound signal input and converting the input into an indicator angle according to the function; and

displaying on the VU meter an indicator image corresponding to the indicator angle indicative of a level of the input sound signal.