JPH0786858B2 - Electronic computer - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic computer, and more particularly to improvement of display of a fraction in an electronic computer such as an electronic desk calculator.

(Prior Art) FIG. 5 shows a schematic plan view of an example of a conventional electronic desk calculator (hereinafter referred to as “calculator”). The calculator shown in FIG. 5 has a liquid crystal display (LCD) 51, a fraction input key 52, a numeral key 53 for inputting a numerical value, and an [=] key 54. The LCD 51 includes a main display portion 51a, a fraction display portion 51b including a numerator display portion 51c and a denominator display portion 51d. When displaying fractions, the numerator and denominator of the fraction are displayed in the numerator display section 51c.
And the denominator display section 51d. When displaying a mixed number, the integer part of the mixed number is further displayed on the main display unit 51a.
Is displayed in.

When inputting a fraction with the calculator shown in Fig. 5, the numeric key 53
Input the numerator using, and press the fraction input key 52 to confirm the numerator. Next, when the denominator is input and the [=] key 54 or the like is pressed, the input fraction is confirmed and, if possible, converted into a divisor and a mixed fraction. When entering a mixed number, enter the integer part of the mixed number using the numeric keys 53 prior to entering the numerator described above, and then enter the fraction input key 52.
Use to confirm.

FIG. 6 shows an operation example for inputting a fraction and a display result accompanying it.

(Problems to be Solved by the Invention) As can be seen from columns B and D of FIG. 6, in the conventional calculator, the numerator and denominator are displayed right justified in the same manner as the integer part in the display of mixed fractions. Was there. Therefore, the integer part and the fractional part of the displayed mixed number are separated from each other, which causes a problem that it is not easy for the operator to recognize the displayed mixed number.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electronic computer capable of displaying a mixed number that is easy for an operator to recognize.

(Means for Solving the Problems) The electronic computer of the present invention has a first display unit capable of displaying an integer part of a mixed number and a second display unit capable of displaying a numerator having a fractional digit. And a display device having a third display unit capable of displaying a denominator of a fraction of a plurality of digits, and at least one of a numerator and a denominator of a fraction to be displayed, of the second display unit and the third display unit. And a means for displaying at a position closest to the first display unit among the corresponding display units in the inside thereof, thereby achieving the above object.

(Examples) The present invention will be described below with reference to Examples.

FIG. 1 shows the appearance of an embodiment of the present invention. Although the present embodiment is a scientific calculator capable of executing calculation of various kinds of functions, regarding the keys, only the keys related to the input and display of fractions will be described below. In this embodiment, a liquid crystal display (LCD) 1 and a keyboard 2 are provided. LCD1
Includes a main display portion 1a for displaying numbers and the like, and a fraction display portion 1b for displaying fractions and the like. In the display of the improper fraction, the numerator is displayed in the numerator display part 1c in the upper part of the fraction display part 1b, and the denominator is displayed in the denominator display part 1d in the lower part of the fraction display part 1b. In displaying the mixed number, the integer part of the mixed number is further displayed on the main display unit 1a. The fraction display section 1b is
As shown in the figure, it is most preferable to be arranged on the right side of the main display portion 1a because it is close to the usual mixed number notation format.

The keyboard 2 is the second function key for selecting the function of the [ab / c] key 2a, [ab / c] key 2a, etc. used when inputting a fraction and converting between improper fractions and mixed fractions. 2b, 0-9
A numeric key 2c for inputting the numerical value of, a key 2d for executing four arithmetic operations, and a [=] key 2e are provided.

A procedure for inputting a fraction in this embodiment will be described. To enter an improper fraction, enter the numerator using the numeric key 2c,
Press the [ab / c] key 2a to confirm the molecule. Next, enter the denominator using the numeric key 2c, and the four arithmetic operation keys 2d,
When the [=] key 2e or the like is pressed, the entered fraction is confirmed. When entering a mixed number, first enter the integer part of the mixed number using the numeric key 2c, confirm the integer part with the [ab / c] key 2a, and then temporarily enter the fractional part of the mixed number. Enter the number in the same way as you enter the fraction. Arithmetic operation key 2d, [=] key
When determining the input fraction by 2e, etc., conversion to a divisor and / or mixed fraction is performed if possible. Improper fraction
Conversion between mixed numbers is performed by pressing the second function key 2b and then the [ab / c] key 2a.

FIG. 2 shows a block diagram of this embodiment. The CPU 21 is connected to a ROM 22 that stores programs and constants, a RAM 23 that stores control data and numerical data, and a key matrix 26 that detects key input using the keyboard 2. The LCD 1 is connected to the CPU 21 via an LCD drive circuit 24 that controls the drive of the LCD 1.

FIG. 3 shows an algorithm of a process for displaying a fraction when the arithmetic key 2d, the [=] key 2e, etc. are pressed when the fraction is input. In FIG. 3, X, Y, and A are variables for storing the number of digits of the denominator after reduction, a variable for storing the number of digits of the numerator after reduction, and the fraction display portion 1b can be displayed. This is a variable for storing the maximum number of digits. Storage locations are allocated in RAM 23 for these variables.

First, the number of digits of the denominator and the number of digits of the numerator of the fraction after the calculation, the reduction, etc. are calculated and substituted into X and Y, respectively (step S1). Further, in step S1, the maximum number of digits that can be displayed on the fraction display unit 1b is obtained and substituted into A. Next, in step S2, X is compared with Y. If X is greater than Y, the process proceeds to step S3, and if X is less than or equal to Y, the process proceeds to step S4.

In step S3, subtract the number of denominator digits X from the maximum number of digits A,
Assign the result to the variable LAP. In step S4, the digit number Y of the numerator is subtracted from the maximum digit number A, and the result is substituted into the variable LAP. By the processing of step S2 and step S3 or S4,
The result obtained by subtracting the larger of the digit number X of the denominator and the digit number Y of the numerator from the maximum digit number A is obtained in the variable LAP. Step S5
Then, the denominator and the numerator are displayed in the denominator display unit 1d (Fig. 1) and the numerator display unit 1c (Fig. 1), respectively, by shifting the denominator and the numerator to the upper digit direction, that is, leftward.

The algorithm of FIG. 3 may be applied only to the display of mixed fractions, or may be applied to both the display of mixed fractions and the display of improper fractions.

FIG. 4 shows an operation example and a display result of this embodiment. The fraction input as shown in the column A of FIG. 4 is confirmed by pressing the [=] key 2e as shown in the column B of FIG. 4, and at this time, it is converted into a divisor and a mixed fraction. Is done. or,
The fractional part of the mixed fraction, according to the algorithm of FIG.
The fraction display portion 1b is displayed left-justified so as to be closest to the main display portion 1a. Column C in FIG. 4 shows the procedure for inputting the mixed fraction. When the inputted mixed fraction is confirmed by pressing the [=] key 2e as shown in the column D of FIG. 4, the fractional part is displayed left justified. Incidentally, in the column D of FIG. 4, the fractional part is also reduced.

In the above-mentioned embodiment, as can be seen from the flowchart of FIG. 3, the numerator and the denominator are displayed by being shifted by the same number of digits, so that the displayed numerator and the denominator are aligned at their right ends. This is not essential to the present invention, and the smaller number of digits of the numerator and denominator may be displaced to the left further than the other so that the right ends of the numerator and denominator are aligned.

(Effects of the Invention) According to the present invention, since the fractional part and the integer part of the mixed fraction are displayed without being separated from each other, the operator can easily recognize the mixed fraction displayed, and the electronic computer with improved operability is provided. Provided.

[Brief description of drawings]

FIG. 1 is a schematic plan view of an embodiment of the present invention, FIG. 2 is a block diagram of the embodiment, FIG. 3 is a flow chart showing an algorithm for displaying fractions in the embodiment, and FIG. FIG. 5 is a plan view of an example of a conventional electronic computer, and FIG. 6 is a diagram showing an operation example and display result of the electronic computer of FIG. 1 ... Liquid crystal display (LCD), 1a ... Main display section, 1b ... Fraction display section, 1c ... Numerator display section, 1d ... Denominator display section, 2 ... Keyboard, 21 ... CPU, 22 ... ROM, 23 ... RAM, 24 … LCD drive circuit, 26
… Key matrix.

Claims (1)

[Claims] 1. A first display unit capable of displaying an integer part of a mixed fraction, a second display unit capable of displaying a numerator of a multi-digit fraction, and a denominator of a multi-digit fraction. And a display device having a third display unit capable of displaying at least one of a numerator and a denominator of a fraction to be displayed in the corresponding display unit of the second display unit and the third display unit. And a means for displaying at a position closest to the display unit of 1.