Digital display system of floating point representation

Claim 2

A digital display system capable of displaying a decimal number composed of up to M-digits, wherein M is an integer, which comprises: means for storing the position of a decimal point included in a signal representative of a decimal number fed from an external electrical device; means for visually representing a symbol X 10n, wherein n is an integer, which corresponds to the multiplication by the use of n-th power of the base 10; and means for determining whether the content stored in said storing means exceeds the value of said integer n, said determining means including means for generating a signal to said representing means only when said content stored in said storing means exceeds the value of said integer n whereby an overflow condition occurs, means to thereby bring said representing means into an operative position by said signal from said generating means and means for concurrently moving the decimal point n-placeS to the left with respect to the position of the decimal point stored in said storing means, resulting in the condition that the effective figures of said number can be read off with the decimal point located n-places to the left.

Claim 3

A digital display system as claimed in claim 1, wherein said representing means includes an index lamp bearing said symbol which can be illuminated upon receipt of the signal from said determining means.

Claim 4

A digital display system as claimed in claim 1, wherein said representing means includes said symbol located to the right of the decimal number thus displayed.

Claim 5

A digital display system as claimed in claim 1, wherein said storing means comprises a pair of series connected counters each capable of generating an output when the number counted thereby attains the value of n.

Claim 6

A digital display system as claimed in claim 1, wherein said storing means comprises a shift register having at least ( 1 + log2n ) bits.

Claim 7

A digital display system comprising: means for displaying a decimal number composed of up to M-digits, wherein M is an integer; means for visually representing a symbol X 10n , wherein n is an integer; a register having a least ( 1 + log2n ) stages for storing a signal representative of a decimal number; a discriminator adapted to receive an output signal from one of said stages of said register which stores the most significant bit of a binary coded number of the decimal point for determining whether the number represented by said output signal from said register exceeds the value n, said discriminator being capable of generating a signal to said representing means only when said number represented by said output signal actually exceeds over the value of n, that is, the overflow condition occurs, to thereby bring said representing means into an operative position by said signal from said discriminator; and a decimal point positioning means adapted to receive output signals representative of binary coded digits which are fed from the stages of the register which stores significant bits of a binary coded number of the decimal point positioned to the right of the most significant bit, for determining the position of the decimal point to be displayed in response to a binary combination of said binary digits represented by said output signals.

Claim 8

A digital display system comprising: means for displaying a decimal number composed of up to M-digits, wherein M is an integer; means for visually representing a symbol X 10n , wherein n is an integer; a register having a least ( 1 + log2n ) stages for storing a signal representative of a decimal number; a discriminator adapted to receive an output signal from one of said stages of said register which stores the most significant bit of a binary coded number of the decimal point for determining whether the number represented by said output signal from said register exceeds the value n, said discriminator being capable of generating a signal to said representing means only when said number represented by said output signal actually exceeds over the value of n, that is, the overflow condition occurs, to thereby bring said representing means into an operative position by said signal from said discriminator; and a decimal point positioning means adapted to receive output signals representative of binary coded digits which are fed from the stages of the register which stores significant bits of a binary coded number of the decimal point positioned to the right of the most significant bit, for determining the position of the decimal point to be displayed in response to a binary combination of said binary digits represented by said output signals.

Claim 9

A digital display system comprising: means for displaying a decimal number composed of up to M-digits, wherein M is an integer; means for visually representing a symbol X 10n wherein n is an integer; a register having (1 + log2n) stages for storing a signal representative of a decimal number fed from an external device, said signal including the position of the decimal point included in said decimal number, an OR circuit arranged so as to receive an output signal from each of said stages of the register other than the stage thereof corresponding to the most significant bit of a binary coded number of the decimal point; a first AND circuit having a pair of input terminals connected with said stage of the register corresponding to the most significant bit and with an output terminal of said OR circuit, an inverter connected with said first AND circuit for inverting the output of said first AND circuit; a second AND circuit having a pair of input terminals connected to the output terminal of said inverter and to the stage of the register corresponding to the most significant bit; a discriminator adapted to receive an output signal from said first AND circuit for determining whether the number represented by said output signal from said first AND circuit exceeds the value of said integer n, said discriminator being capable of generating a signal to said representing means only when said number represented by said output signal actually exceeds the value of said integer n, that is, the overflow condition occurs, to thereby bring said representing means into an operative position by said signal from said discriminator; and a decimal point positioning means adapted to receive an output signal from said second AND circuit and output signals representative of binary coded digits which are fed from the other stages of the register except for that corresponding to the most significant bit, for determining the position of the decimal point to be displayed in response to a binary combination of said binary digits represented by said output signals.

Claim 10

A digital display system comprising: means for displaying a decimal number composed of up to M-digits, wherein M is an integer; means for visually representing a symbol X 10n wherein n is an integer; a register having (1 + log2n) stages for storing a signal representative of a decimal number fed from an external device, said signal including the position of the decimal point included in said decimal number, an OR circuit arranged so as to receive an output signal from each of said stages of the register other than the stage thereof corresponding to the most significant bit of a binary coded number of the decimal point; a first AND circuit having a pair of input terminals connected with said stage of the register corresponding to the most significant bit and with an output terminal of said OR circuit, an inverter connected with said first AND circuit for inverting the output of said first AND circuit; a second AND circuit having a pair of input terminals connected to the output terminal of said inverter and to the stage of the register corresponding to the most significant bit; a discriminator adapted to receive an output signal from said first AND circuit for determining whether the number represented by said output signal from said first AND circuit exceeds the value of said integer n, said discriminator being capable of generating a signal to said representing means only when said number represented by said output signal actually exceeds the value of said integer n, that is, the overflow condition occurs, to thereby bring said representing means into an operative position by said signal from said discriminator; and a decimal point positioning means adapted to receive an output signal from said second AND circuit and output signals representative of binary coded digits which are fed from the other stages of the register except for that corresponding to the most significant bit, for determining the position of the decimal point to be displayed in response to a binary combination of said binary digits represented by said output signals.

Claim 11

A display system comprising: first means for providing a display of a decimal number; and second means, responsive to a first signal corresponding to said decimal number, for supplying first and second indication signals to said first means, said first and second indication signals respectively corresponding to a predetermined number of decimal digits of said decimal number for displaying said predetermined number of decimal digits and a representation of a factor corresponding to an integral power of 10, said factor, when multiplied by said predetermined number of digits, providing an indication representing said decimal number according to a predetermined number of significant digits and the same number of digits of which said decimal number is composed for displaying said factor.

Claim 12

A display system comprising: first means for providing a display of a decimal number; and second means, responsive to a first signal corresponding to said decimal number, for supplying first and second indication signals to said first means, said first and second indication signals respectively corresponding to a predetermined number of decimal digits of said decimal number for displaying said predetermined number of decimal digits and a representation of a factor corresponding to an integral power of 10, said factor, when multiplied by said predetermined number of digits, providing an indication representing said decimal number according to a predetermined number of significant digits and the same number of digits of which said decimal number is composed for displaying said factor.

Claim 13

A display system according to claim 8, wherein said second means includes means , responsive to a signal representative of the position of the decimal point with respect to the most significant digit of said decimal number for comparing said representative signal with a stored number, and upon the number of digits representing said decimal point corresponding to said representative signal exceeding said stored number, for generating said second indication signal to be supplied to said first means.

Claim 14

A display system according to claim 8, wherein said second means further includes means, responsive to a signal representative of the number of significant digits of said decimal number, for storing said number of digits and, upon the number of digits stored exceeding a predetermined number, for generating a first output signal therefrom, and further including means, responsive to said first output signal of said storing means and the number of significant digits stored therein for subtracting therein said predetermined number of digits from said number of significant digits and for providing a second output signal representative of the difference.

Claim 15

A display system according to claim 10, wherein said second means further includes means, coupled to the output of said subtracting means and to a numerical display provided in said first means, for providing a decimal point indication superimposed on said first indication signal corresponding to the difference between said number of significant digits and said predetermined number of digits.

Claim 16

A display system according to claim 11, wherein said first means comprises first and second display windows, the first of which comprises a number of numerical display indicators corresponding to said predetermined number and said second display comprises a numerical indicator for indicating a factor of an integral power of 10, said first and second indication signals being supplied to the indicators of said first and second display windows, respectively.

Claim 17

A display system according to claim 12, wherein said second means further includes means, responsive to the first output signal provided by said storing means, for comparing said first output signal with a predetermined number, and upon the number of significant digits represented by said first output signal exceeding said stored number for generating said second indication signal to be supplied to the numerical indicator of said second display window.

Claim 18

A display system according to claim 13, wherein said decimal indicator superimposing means comprises a decimaL point positioning circuit, responsive to the output of said storing means, said storing means being fed with the output of said subtracting means, for supplying to said decimal point positioning circuit the difference signal therefrom.

Claim 19

A display system according to claim 14, wherein said second means further includes means, responsive to a series of digital signals representing a decimal number in binary form for decoding said decimal number into decimal form and providing driving signals to the numerical indicators of said first display window.

Claim 20

A display system according to claim 15, wherein said comparing means comprises a discriminator circuit and a flip-flop circuit connected between the output of said storing means and said second numerical indicator.

Claim 21

A display system according to claim 8, wherein said second means further includes means, responsive to a signal representative of the number of significant digits of said decimal number, for storing said representative signal and for generating a digital output representative of the position of the decimal point of said decimal number with respect to the most significant digit thereof.

Claim 22

A display system according to claim 17, wherein said second means further includes means, responsive to the output of said storing means and being coupled to a numerical display provided in said first means, for superimposing a decimal point indication signal on said first indication signal supplied to said first means.

Claim 23

A display system according to claim 18, wherein said first means comprises first and second display windows, the first of which includes a number of numerical display indicators corresponding to said predetermined number and said second display window comprises a numerical indicator for indicating a factor of an integral power of 10, said first and second indication signals being supplied to the indicators of said first and second display windows, respectively.

Claim 24

A display system according to claim 19, wherein said second means further includes means, responsive to the output provided by said storing means for comparing the output of said storing means with a predetermined number, and upon the number of digits between the most significant digits and the decimal point represented by the output signal of said storing means exceeding said storage number for generating said second indication signal to be supplied to the numerical indicator of said second display window.

Claim 25

A display system according to claim 19, wherein said storing means comprises a shift register for providing a plurality of digital signals therefrom corresponding to a digital indication of the position of said decimal point with respect to the most significant digits of said decimal number and wherein said second means further includes means, coupled to the output of said comparing means, and to a numerical display provided in said first means, for providing a decimal point indication superimposed on said first indication signal corresponding to the position of said decimal point with respect to the most significant digit of said decimal number.

Claim 26

A display system according to claim 21, wherein the output of the first stage of said shift register is connected to said comparing means.

Claim 27

A display system according to claim 22, wherein said second means further includes means, responsive to a series of digital signals representing said decimal number in binary form for decoding said decimal number into decimal form and for providing driving signals to the numerical indicators of said first display window and wherein said comparing means comprises a discriminator circuit and a flip-flop circuit connected between the output of said shift register and said second numerical indicator.

Claim 28

A display system according to claim 21, further including first and second AND gates, each having a common input connected to the first stage of said shift register within said storage means, a second output of said First AND gate being coupled to each of the outputs of the remaining stages of said shift register within said storing means, the output of said first AND gate providing said second indication signal and being coupled to the other input of said second AND gate through an inverter circuit, the output of said second AND gate being connected to said decimal point position circuit.

Claim 29

A display system according to claim 21, wherein said arithmetic calculator unit comprises first and second circulating shift registers, each receiving said digital input signals representative of said decimal number and coupled at the respective outputs thereof to a full adder circuit, the output of which is coupled to the input of said storing means, further including first and second AND gates, each having a common input connected to the first stage of said shift register within said storage means, a second output of said first AND gate being coupled to each of the outputs of the remaining stages of said shift register within said storing means, the output of said first AND gate providing said second indication signal and being coupled to the other input of said second AND gate through an inverter circuit, the output of said second AND gate being connected to said decimal point position circuit.

Claim 30

A display system according to claim 17, further including an arithmetic calculator unit, responsive to digital input signals representative of a decimal number, for supplying said signal representative of the number of significant digits of said decimal number and the position of said decimal point with respect to the most significant digit to said storing means.

Claim 31

A display system according to claim 26, wherein said arithmetic calculator unit comprises said first and second circulating shift registers, each receiving said digital input signals representative of said decimal number and coupled at the respective outputs thereof to a full adder circuit, the output of which is coupled to the input of said storing means.

Claim 32

A display system according to claim 27, wherein the output of said shift register of said storing means is fed back to the input thereof in parallel with the output of said full adder circuit and the digital signals representative of said decimal number.