Description:
BACKGROUND OF THE INVENTION
This invention relates to an electronic musical instrument and more particularly to an electronic musical instrument provided with a plurality of tone volume setters for presetting the amplitude levels of musical tone signals of respective tone color voices.
Generally, in an electronic musical instrument, a plurality of musical tone signals bearing different tone color voices are mixed on the basis of amplitude levels chosen by a player. To this end, the electronic musical instrument is provided with a plurality of tone volume setters for presetting the amplitude levels of musical tone signals of respective particular tone colors, thereby determining the tone color of the out-coming musical signals. During performance, the player selects any one or ones of the amplitude level presetting devices to decide the voice he wants. Further, the player can control the amplitude levels of musical tone signals given forth during performance by operating tone levers provided on the control panel of an electronic musical instrument, without relying on the aforesaid presetting devices.
The above-mentioned amplitude level presetting devices, except for the selection switches thereof, are generally received in a drawer provided in an electronic musical instrument. Unless, therefore, the drawer is pulled out, the amplitude level setting states or preset states of musical tone signals in the presetting devices can not be recognized. In this case, recognition of such conditions can only be confirmed by the movement of the movable elements of the tone volume setters of the presetting devices. However, the withdrawal of the drawer obstructs performance.
SUMMARY OF THE INVENTION
It is accordingly the object of this invention to provide an electronic musical instrument, which, where one of the amplitude level presetting devices is selected by a player, enables him easily to observe by the eye, even during performance, the state in which the selected presetting device presets the amplitude levels of respective tone color signals.
An electronic musical instrument according to this invention comprises a plurality of devices interlocking with the tone volume setters of the presetting devices for presetting the amplitude levels of respective tone color signals so as to deliver control voltages representing the preset amplitude levels and indicating means responsive to the voltage. Thus, control voltages representing the amplitude level set state or preset state of respective tone color signals in a presetting device selected through a selection switch are impressed on the corresponding indicating means to display the preset state.
According to an embodiment of this invention, each of indicating means includes, for example, a single indicator such as a lamp or a light-emission diode, which gives forth such degree of illumination as responsive to the magnitude of output voltage from the voltage deliverer. According to another embodiment of the invention, each of indicator means includes a plurality of indicators such as lamps or light-emission diodes. In this case, there are further provided a plurality of voltage level detectors having different threshold voltage levels so as to distinguish the magnitude of output voltage from the voltage deliverer. There are lighted a sufficient number of indicators to represent the magnitude of output voltage from the deliverer. In this case, any preset amplitude level of respective tone color signals is indicated by the number of the indicators which are lighted on. Each of the indicating means may be disposed adjacent to the tone lever provided on the control panel of an electronic musical instrument for manually controlling the amplitude level of the associated musical tone signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 presents the circuit arrangement of an electronic musical instrument according to an embodiment of this invention which is provided with a plurality of devices for indicating the preset amplitude levels of respective tone color signals;
FIG. 2 indicates a modification of the indicating means used in the embodiment of FIG. 1;
FIG. 3 shows the relative position of the numerous indicators of FIG. 2 for displaying the preset state as well as the manually control led state of the amplitude level; and
FIG. 4 is a concrete circuit diagram of a voltage level detector used in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For convenience of description, musical tones generated in an electronic musical instrument according to the embodiment of FIG. 1 are supposed to have such tone colors or voices as are derived from three natural musical instruments, for example, a flute, a string instrument and an oboe. As in the prior art electronic musical instrument, tone signals from tone generators 11 are supplied to tone coloring filters 13, 14 and 15 through a keyboard section including keyboards and keyers. Connected to the output sides of the tone coloring filters 13, 14 and 15 are a plurality (three in this embodiment) of amplitude level presetting devices 16a, 16b and 16c. The presetting device 16a has tone volume presetters 17Fa, 18Sa and 19Oa supplied with output signals from the tone coloring filters 13, 14 and 15 respectively. Similarly, the presetting devices 16b and 16c have a group of tone volume presetters 17Fb, 18Sb and 19Ob and a group of tone volume presetters 17Fc, 18Sc and 19Oc respectively. The tone volume presetters define the amplitude levels of respective tone color signals when the movable elements thereof are removed. Output signals from the tone volume presetters of any of the presetting devices 16a, 16b and 16c are combined and selectively conducted to a utilization circuit including an amplifier 21 and loudspeaker 22 through a switch 20 for selecting one of the presetting devices. The tone volume presetters 17Fa, 18Sa and 19Oa of the presetting device 16a are mechanically coupled with the corresponding variable resistors 23Fa, 24Sa and 25Oa which represent the amplitude levels of musical tone signals preset by the tone volume presetters. The movable elements of the tone volume presetters and the corresponding variable resistors are gang-operated, and the variable resistors are connected at one end to a D.C. source (+V) and the other to ground. Accordingly, control voltage having a magnitude representing the set position of the tone volume presetter is drawn out from the movable element of the corresponding variable resistor. As in the presetting device 16a, the tone volume presetters 17Fb, 18Sb and 19Ob of the presetting device 16b are mechanically coupled to the corresponding variable resistors 23Fb, 24Sb and 25Ob, and the tone volume presetters 17Fc, 18Sc and 19Oc of the presetting device 16c to the corresponding variable resistors 23Fc, 24Sc and 25Oc. Output signals from the variable resistors 23Fa, 23Fb and 23Fc for representing the set levels of a musical tone signal from the flute filter 13 preset by the tone volume presetters 17Fa, 17Fb and 17Fc are selectively conducted to an indicator 27F consisting of, for example, a lamp or a light-emission diode through a switch 26F interlocking with the selection switch 20 of the presetting devices 16a, 16b and 16c. Similarly, output signals from the variable resistors 24Sa, 24Sb and 24Sc representing the preset amplitude levels of a musical tone signal from the string filter 14 preset by the tone volume presetters 18Sa, 18Sb and 18Sc are selectively supplied to an indicator 27S through a switch 26S interlocking with the selection switch 20. Output signals from the variable resistors 25Oa, 25Ob and 25Oc representing the preset amplitude levels of a musical tone signal from the oboe filter 15 are selectively transmitted to an indicator 27O through a switch 26O interlocking with the selection switch 20.
As seen from the foregoing description, when one presetting device is selected by the selection switch 20, then the indicators 27F, 27S and 27O are lighted with such brightness as indicates the preset amplitude levels of the respective tone color signals associated with the selected presetting device which are being derived for performance. Since the indicators 27F, 27S and 27O and the selection switch 20 are mounted on the control panel of an electronic musical instrument, a player can easily recognize during performance the amplitude level of the respective tone color signals preset by the selected presetting device simply by looking at the brightness with which the indicators are lighted.
An electronic musical instrument is so designed as to enable a player to control during performance the amplitude level of musical tone signals by manually operating tone levers mounted on the control panel of the instrument, as well as by the above-mentioned presetting devices. To this end, the electronic musical instrument is further provided with tone volume setters 28F, 28S and 28O, output signals from which are supplied in a mixed state to the amplifier 21 through the selection switch 20. The movable elements of the tone volume setters 28F, 28S and 28O are projectively provided on the control panel so as to be operated from above. In this case, the indicators may be positioned adjacent to the tone levers for manual control.
FIG. 2 indicates a modification of the indicating means used in the embodiment of FIG. 1. According to this modification, an output signal from the switch 26F is supplied to voltage level detectors 31Fa, 31Fb, 31Fc and 31Fd whose threshold levels vary in succession. Indicators 27Fa, 27Fb, 27Fc and 27Fd are connected to the outputs of the voltage level detectors 31Fa, 31Fb, 31Fc and 31Fd respectively. Thus, control voltage is supplied to any of the voltage level detectors which happens to have a lower threshold voltage than the magnitude of the control voltage to render the voltage level detector conducting, thereby impressing the power source voltage on the indicator connected to the voltage level detector so as to light it. Namely, there are lighted a sufficient number of indicators to show the amplitude level of musical tone signals preset by any of the presetting devices. Voltage level detectors 31Sa, 31Sb, 31Sc and 31Sd and indicators 27Sa, 27Sb, 27Sc and 27Sd are connected, as shown in FIG. 2, to the output side of the switch 26S. Voltage level detectors 31Oa, 31Ob, 31Oc and 31Od and indicators 27Oa, 27Ob, 27Oc and 27Od are connected to the output side of the switch 26O.
A voltage level detection circuit may be arranged as indicated in FIG. 4. Numerals Tr1 and Tr2 denote transistors constituting a Schmitt trigger circuit, whose threshold voltage is determined by a variable resistor VR. Where control voltage impressed on the base of the transistor Tr1 has a higher level than the threshold voltage level, then the transistor Tr1 is rendered conducting, causing the other transistor Tr2 to be non-conducting. When the transistor Tr2 thus is rendered nonconductive, a third transistor Tr3 is turned on to impress power source voltage on an indicator for its lighting through the collector-emitter path of the transistor Tr3.
FIG. 3 illustrates a plurality of indicators 27Fa, 27Fb, 27Fc and 27Fd for displaying the preset amplitude level of musical tone signals from the flute tone coloring filter 13 arranged on the control panel 34 adjacent to a tone lever 33 for manually controlling the amplitude level of the musical tone signal from the flute tone coloring filter 13. The arrows indicated in FIG. 3 show the direction in which the tone lever 33 is manually moved through a slit 35 by a player.
If the selection switches 20, 26F, 26S and 26O consist of electronic switches or relays, their switchover operation can be easily effected by a player, for example, through a push button.