Electronic calculator

Claim 2

Electronic apparatus comprising: input means for entering numerical data and operational instructions; memory means for storing the numerical data; processing means for processing the numerical data stored in said memory means in response to said operational instructions; display means for providing a visual display of the processed numerical data; selecting means settable to a first state and a second state such that the display of numerical data processed in said processing means is enabled when said selecting means is in the first state; and means responsive to the second state of said selecting means for disabling the display of the processed numerical data.

Claim 3

Electronic apparatus according the claim 1 further comprising comparator means for comparing the processed numerical data with predetermined numerical data entered by said input means.

Claim 4

Electronic apparatus according to claim 2, wherein said comparator means includes means for producing a coincidence signal when coincidence exists between the processed numerical data and the predetermined data, and wherein said apparatus further comprises control circuitry responsive to the second state of said selecting means and to the coincidence signal for providing a display indication on said display means.

Claim 5

An electronic calculator comprising: input means for entering numerical data and operational instructions; memory means for storing the numeral data; processing means for processing the numerical data stored in said memory means in response to said operational instructions; display means for providing a visual display of the processed numerical data; means for selectively disabling the display of processed numerical data; and means for indicating that said display of processed numerical data is disabled.

Claim 6

An electronic calculator comprising: input means for entering numerical data and operational instructions; memory means for storing the numeral data; processing means for processing the numerical data stored in said memory means in response to said operational instructions; display means for providing a visual display of the processed numerical data; means for selectively disabling the display of processed numerical data; and means for indicating that said display of processed numerical data is disabled.

Claim 7

An electronic calculator according to claim 4, further comprising means for comparing the processed numerical data with predetermined numerical data entered by said input means, and for subsequently enabling the display of said data when coincidence exists between said processed and predetermined data.

Claim 8

An electric calculator comprising: an input keyboard containing numeral keys for the input of numerical data into said calculator, function keys for the input of operation commands into said calculator and instruction keys for ordering the execution of instructions; registers for storing the numerical data; a display unit for indicating numerical data; a processing circuit for processing the numerical data stored in said registers according to the operation specified by said function keys; circuit means connected to said display unit for selectively disabling the display of the processed numerical data; means for indicating that said display of the processed numerical data is disabled; a comparing circuit for comparing, in response to the instruction given by said instruction keys, the processed numerical data with predetermined numerical data supplied through said keyboard; and an enabling circuit means connected to said display unit for enabling said display unit to display the processed numerical data when the comparison performed by said comparing circuit detects coincidence between the processed and predetermined data.

Claim 9

An electric calculator comprising: an input keyboard containing numeral keys for the input of numerical data into said calculator, function keys for the input of operation commands into said calculator and instruction keys for ordering the execution of instructions; registers for storing the numerical data; a display unit for indicating numerical data; a processing circuit for processing the numerical data stored in said registers according to the operation specified by said function keys; circuit means connected to said display unit for selectively disabling the display of the processed numerical data; means for indicating that said display of the processed numerical data is disabled; a comparing circuit for comparing, in response to the instruction given by said instruction keys, the processed numerical data with predetermined numerical data supplied through said keyboard; and an enabling circuit means connected to said display unit for enabling said display unit to display the processed numerical data when the comparison performed by said comparing circuit detects coincidence between the processed and predetermined data.

Claim 10

An electronic calculator according to claim 6, further comprising a circuit connected to said comparing circuit for erasing the processed data, when non-coincidence is detected by the comparing circuit.

Claim 11

An electronic calculator comprising: input means for entering numerical information and operational instructions; arithmetic operating means connected to said input means for performing arithmetic operations on the numerical information to produce result information in response to the operational instructions; display means for displaying the result information; a memory for storing result information; means for selecting between first and second operational modes; first control means responsive to a selection of the first mode for controlling said arithmetic operating means to supply the result information to said display means; second control means responsive to a selection of the second mode for controlling said arithmetic operating means to store result information in said memory; third control means also responsive to a selection of the second mode for controlling said arithmetic operating means to perform arithmetic operations to compare the result information in the memory with numerical information subsequently entered by said numerical information input means; and fourth control means responsive to a comparison result from the arithmetic operating means controlled by said third control means for supplying or inhibiting the supply of said result to said display means.

Claim 12

An electronic calculator comprising: input means for entering numerical information and operational instructions; arithmetic operating means connected to said input means for performing arithmetic operations on the numerical information to produce result information in response to the operational instructions; display means for displaying the result information; a memory for storing result information; means for selecting between first and second operational modes; first control means responsive to a selection of the first mode for controlling said arithmetic operating means to supply the result information to said display means; second control means responsive to a selection of the second mode for controlling said arithmetic operating means to store result information in said memory; third control means also responsive to a selection of the second mode for controlling said arithmetic operating means to perform arithmetic operations to compare the result information in the memory with numerical information subsequently entered by said numerical information input means; and fourth control means responsive to a comparison result from the arithmetic operating means controlled by said third control means for supplying or inhibiting the supply of said result to said display means.

Claim 13

Electronic apparatus comprising: input means for entering numerical data and operational instructions; arithmetic operating means connected to said input means for performing arithmetic operations on the numerical information to produce result information in response to the operational instructions; a memory connected to said operating means for storing the result information; first control means for controlling said operating means to perform arithmetic operations on numerical information including first and second operands and to supply result information from said arithmetic operating means to said memory; second control means for controlling said operating means to perform arithmetic operations to compare the result information with numerical information subsequently entered by said numerical input means; third control means connected to said arithmetic operating means and being responsive to a comparison result from said operating means, controlled by said second control means, for supplying or inhibiting the supply of said comparison result as an output signal of said arithmetic operating means; and display means responsive to either of said third control means and said input means for displaying the result information and comparison result information.

Claim 14

Electronic apparatus comprising: input means for entering numerical data and operational instructions; arithmetic operating means connected to said input means for performing arithmetic operations on the numerical information to produce result information in response to the operational instructions; a memory connected to said operating means for storing the result information; first control means for controlling said operating means to perform arithmetic operations on numerical information including first and second operands and to supply result information from said arithmetic operating means to said memory; second control means for controlling said operating means to perform arithmetic operations to compare the result information with numerical information subsequently entered by said numerical input means; third control means connected to said arithmetic operating means and being responsive to a comparison result from said operating means, controlled by said second control means, for supplying or inhibiting the supply of said comparison result as an output signal of said arithmetic operating means; and display means responsive to either of said third control means and said input means for displaying the result information and comparison result information.

Claim 15

Electronic apparatus according to claim 9, further comprising fourth control means connected to said display means for controlling said display means to display a symbol representative of no-coincidence together with the numerical information received by the numerical input means when no coincidence occurs between the numerical information entered by the numerical input means and the result information stored in said memory.

Claim 16

Electronic apparatus according to claim 10, further comprising fifth control means responsive to renewed numerical information entered by the numerical input means for clearing the display of the symbol and the result information stored in said memory.

Claim 17

Electronic apparatus according to claim 9, further comprising means connected to said display means for causing said display means to display a symbol representative of coincidence together with the result information stored in said memory when coincidence occurs between the numerical information received by the numerical input means and the result information stored in said memory.