JPS5837759A - Electronic desk top calculator with melody - Google Patents

Abstract

PURPOSE:To keep musical scale to a prescribed frequency while a key is depressed, by storing a musical scale setting ROM output to a latch during the depression of the key and switchingly controlling an oscillating frequency of an oscillation circuit through the detection of this latched output. CONSTITUTION:In an electronic desk top calculator with melody, a phenomenon that a musical scale is changed through the change from a high frequency during operation into a low frequency of post processings on the way if a key is kept depressed, is prevented. When the key is depressed, an output IC1 of ROM for musical scale setting is outputted and a tone scale frequency corresponding to entry keys is set. This output IC1 is stored in a latch circuit I1. The output of the I1 is detected at a detection circuit 9 and an oscillation circuit 3 is oscillated in a high frequency. While the tone is given, an output of a NOR circuit NR4 of the circuit 9 goes to ''0'', and even if an operation display switching signal goes to ''1'', the output of an AND circuit AG remains ''0'' and the oscillation frequency of the oscillator 3 remains to the high frequency, then the musical scale can be kept to a prescribed frequency during the depression of the key.

Description

[Detailed description of the invention] The present invention relates to an electronic desktop calculator with a melody.

In recent years, electronic desktop calculators (hereinafter simply referred to as calculators) that can play melodies have been on the market. Most of these calculators use numeric keys (n to figure) and decimal point keys, and the scale assigned to each key is sounded by a piezoelectric pad.For example, the key opening is low. Tsu (L, a), 1
11 is assigned as low B (B1), ■ is assigned as C (Do), IID is assigned as Re (re), and DH is assigned as high (re), and the melody can be played by pressing each key.

By the way, these scales are not absolute scales, and the scales (frequency) vary depending on the reference clock of the calculator, but the difference between each scale is constant.

Furthermore, the length of a note is determined by the length of time a key is pressed, and if you want to play a long note, you must hold down that key for a long time.

On the other hand, for calculators themselves, the mainstream is a frequency switching system that reduces power consumption by switching to a high frequency during calculations and then switching to a low frequency when displaying to reduce power consumption. Therefore, when considering numbers on a conventional calculator, as shown in Figure 1, the number processing is processed at high frequency, and the post-processing is processed and displayed at low frequency. During processing, the post-processing routine continues until the key is released in order to distinguish it from the next key. If the thumb and key are held down and the fc key is held down, low frequency display will be performed during post-processing. For example, when playing a long note on a conventional calculator with a melody, it is set to 11 by pressing a certain numeric key, but the scale is set before the calculation result and during calculation due to the calculation speed. If you set it to a high frequency and hold down the key, it will change to the low frequency of the post-processing (displaying) midway through, causing the scale to go out of order.
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The present wA was made to eliminate the above-mentioned drawbacks, and includes a latch means that holds the scale setting ROM output while the key is pressed, and a latch means that detects the output of this latch means and waits for the scale specification period. By providing a means for detecting this, and controlling the oscillation frequency of the oscillation circuit by switching the oscillation frequency of the oscillation circuit based on the detection output of this detection means, the melody can be created so that the scale can be maintained at a constant frequency while the key is pressed, eliminating any deviations in the scale. The purpose is to provide an electronic desktop calculator.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Fig. 2 shows the basic number 70- of the electronic desk calculator with melody of the present invention, which operates at a low frequency when the number key is pressed during the key wait in step S1 and the preprocessing in step Ss. , during the calculation which is the numeric value setting process in step 8I, it operates at a high frequency, and at this point a good tone scale is set corresponding to the current numeric value key. This produces a p sound and steps ε
The process moves to post-processing 2, but if the middle key is still pressed here, the process returns to the scale setting process in step S4, which is processed using high frequency, and the scale is set using high frequency again, Stella fB,
through the high frequency post-processing 1 and also the high frequency step 8I
The operation of setting the scale KjI is repeated. Therefore, steps 84e8g are repeated while the key is pressed, and when the key is released, the control operation shifts from step Ss post-processing 1 to step S. which is low frequency post-processing 2.

In Figure 0, which shows the main circuit that realizes the basic operation described above in Figure wJ3, 11 to 1 are clocked inverters CI.
I IC1, and NOR circuit NR.

This latch circuit 11-1 is a latch circuit composed of
Each company uses the output IC1 to ICF of a ROM (read-only memory) for setting scales (not shown) as a sound start signal φ1 and an innotator! This star signal φ1, which is taken in in synchronization with the inverted start signal φ1 inverted at step 1, is a signal that is output when a sound starts to be played in the flow, and is a signal that is sequentially output when a new sound starts. These latch circuits 11 to 1 receive a signal SR and a signal hc at the end of the sound.

The latch operation is controlled by the NAND circuit NA, which inputs p. 2 is the basic clock generation circuit, resistor RI
IB dew, capacitance C1 in I4-ta l-In and transmission r
-) It is composed of an oscillator 3 formed by TG whose oscillation frequency can be switched, and a flip-frog which receives the output of this oscillator 3 and forms a basic clock XT. Reference numeral 6 denotes a frequency dividing circuit that divides the basic clock XT from the generation circuit 2 to obtain the frequency f of a predetermined scale.
Output l0=f ~ Corresponding to IC7, 7 flip-flops 61 to 61 with reset priority, and this Arilag Flora! Reset NOR circuits NR connected to the reset terminals 61 to 61, respectively, and these seven lip-flops 6.
A NOR circuit NR inputs each output of 1 to 6 TE, and the output of this NOR circuit NR is inputted to generate the basic clock X! The flip-flop 1 is provided with a flip-flop 1 which operates at a frequency f, and a flip-flop 1 which inputs the output of the flip-flop 1 to obtain the predetermined scale frequency f. Note that the outputs of the respective latch circuits 11 to 11 and the output signal of the 7 lip-frog 1 are supplied to each of the reset NOR circuits NRI.

t, - are detection circuits having a NOR circuit NR4 which receives the outputs of the latch circuits 11 to 1 and detects the key for which a scale is set (the key is pressed), and 10 is a frequency switching circuit. , an AND gate AG which inputs the output signal of the NOR circuit NR, and a calculation/display switching signal for switching between calculation and display, and an inverter which inverts the output of the AND gate AG! I have a life.

The transmission dart τG of the oscillator 3 is turned on by the oscillation frequency switching signal from the O switching circuit 10, and the oscillator 3
The oscillation frequency of is determined from the frequency set by the constant J+C1 by the constant R1*R*C1! It is set to switch to the set frequency.

Next, the circuit operation of the calculator with melody will be briefly explained. Now, when a certain key is pressed, the corresponding scale setting RO
The output of M, for example ICf, is output, and the scale frequency corresponding to the numeric key is set based on the output ICJK of this scale setting ROM. The output ICI of this ROM is stored in the latch circuit 11 in response to the sound start signal φ1.

This latch circuit 1*Id, the output ICJ of the stored ROM
is held until the start signal φ1 of the next new tone is output or until the end signal SR of that tone is output. In this case, the output of the NOR circuit NR4 of the detection circuit 9 is F when the scale is set.
Since it is at the i''o' level, the AND p − of the switching circuit 10
) The output of A G will be @01. Therefore, oscillation@3 is oscillating at a high frequency. The high JliilIIL basic clock XT generated from the flip-flop 4 is sent to the frequency divider circuit 5.
The frequency is divided by the scale corresponding to the output ICI of the ROM,
Obtain the scale frequency f corresponding to the number key.

Here, when setting the scale, one of the outputs of this scale setting ROM is always specified as 11 levels, so while the tone is sounding, the output of the NOR circuit NR4C of the detection circuit 9 is ""0. #0# level, even if the arithmetic display switching signal becomes @1# level, the output of AND GOTO G remains at 10# level, and the oscillation frequency remains high. Signal 1 indicating the end of the sound when the pressed key is released
When 1 becomes "1#" or when the next key is pressed and the new sound start signal φ becomes 1#, latch circuit 1
! The output ICI of the 7'j ROM is cleared, and the NOR circuit NRA Om output becomes the level B@s'. Therefore, the ANDr−)AG of the switching circuit 10 is “
Its output is "1" level calculation display switching signal.
# The output signal of this switching circuit 10C) turns on the TG of the oscillator 3, switches the oscillation frequency of this oscillator SO from the high frequency tλ to the low frequency, and performs post-processing.

In this way, with the above-mentioned calculator with melody, when the key is pressed at t, when the tsume p scale is specified, that state is detected and the high frequency t is output without changing the frequency even during post-processing.
By keeping it at -i, you can keep lSI& at a constant frequency, so even if you keep pressing the key for a long time, the scale will be out of order.

As explained above, according to the present invention, the latch means holds the output of the scale setting ROM that sets the scale corresponding to the L1 number key while the number key is pressed, and the output of this latch means. The oscillation frequency of the oscillation circuit is controlled by switching the oscillation frequency of the oscillation circuit based on the detection output of this detection means, so as long as the key is pressed, the scale is kept at a constant frequency and the scale is played. It is possible to provide an electronic desktop calculator with a melody that can eliminate the confusion.

[Brief explanation of the drawing]

The first @ is the conventional melody (number 70 on the calculator - cheat,
FIG. 2 is an Ill flow chart of a calculator with a melody according to the present invention. FIG. 3 is a block diagram of a mourning S circuit showing an embodiment of a calculator with a melody according to the present invention. 1...Latch circuit, 2...Basic clock generation circuit,
3... Departure! 4, 6, 1.8...Flip frog, 5...Branch circuit, 9...Detection circuit, 10...
・Frequency switching circuit.

Claims (1)

[Claims] In an electronic desktop calculator with a melody that changes the oscillation frequency of the oscillation circuit to generate the notes of the scale corresponding to the number keys, while the front number key is pressed, the scale corresponding to the number key is played. a latch means for holding the output of the scale setting circuit to be set; a division means for dividing the oscillation output of the oscillation circuit by the output of the latch means to obtain a frequency signal of the scale corresponding to the pressed key; and a means for switching the oscillation frequency of the oscillation circuit according to the detection output of the detection means, and the scale is kept constant while the key is pressed. An electronic desktop calculator with a melody that maintains the frequency.