Electronic cash register capable of calculating sales tax

A method for calculating a sales tax imposed upon a total mount of sales based on a predetermined sales tax collection schedule in an electronic cash register which performs a registering operation and provides an electrical signal output representative of said taxable total amount of sales, and which schedule comprises a series of imposable tax values and respectively corresponding ranges of taxable sales amounts including therein a portion comprising a pattern of widths of successive said ranges for corresponding, successive said tax values, said method comprising the steps of

• storing said pattern of widths of said successive ranges and respectively corresponding tax values throughout said portion of said collection schedule,
• deducting from said total amount of sales the largest possible integral number of full cycles of the taxable amount of the repeatedly occurring pattern of said portion, as stored,
• indexing a first imposable tax corresponding to said total amount of sales, as deducted, by referring to said stored pattern of said widths of said ranges for the corresponding tax values throughout said portion of repeatedly occurring patterns of said collection schedule,
• multiplying the imposable tax amount for a full cycle of the repeated pattern of said portion by said largest possible integral number of full cycles of the repeated pattern for providing a second corresponding sales tax imposable upon said integral number of full cycles of the taxable amount for the repeated pattern in said portion, and adding said first and second imposable tax amounts for providing as an output the total amount of sales tax imposed upon said taxable total amount of sales.

An electronic cash register for performing a registering operation for providing a total amount of sales and for calculating a sales tax imposed upon said total amount of sales based upon a predetermined sales tax collection schedule which comprises a series of imposable tax values for respectively corresponding ranges of the taxable sales amounts and includes therein a portion comprising a pattern of widths of successive said ranges for successively increasing, respectively corresponding tax values occurring repeatedly in successive cycles and in a regular fashion for increasing tax values, said electronic cash register comprising:

• keying input means for manual entry of numerical information,
• means for manually selecting an operation mode of said cash register, said cash register having a schedule information entering mode, a registering mode, and an imposable sales tax calculating mode,
• storage means having locations for storing at least data concerning said pattern of widths of said successive ranges and the respectively corresponding tax values thereof, throughout said portion of said collection schedule,
• means responsive to an output from said operation mode selecting means representative of the selection of said schedule information entering mode and an output from said keying input means representative of said data to be stored, in accordance with manual entry on said keying input means of that data as numerical information, for storing said data in said storage means,
• means responsive to an output from said operation mode selection means representative of the selection of said registering mode and an output from said keying input means representative of an amount of sales for each commodity, in accordance with manual entry of the amount of sales on said keying input means as numerical information, for calculating said total amount of sales,
• means responsive to an output from said operation mode selection means representative of selection of said imposable sales tax calculating mode, for reading said data from said storage means,
• means responsive to an output from said means for calculating said total amount of sales and an output from said means for reading said data, for calculating said sales tax imposed on said total amount of sales, based on said predetermined sales tax collection schedule, said sales tax calculating means comprising
• means responsive to an output from said storage means and the output representative of said total amount of sales for deducting the largest possible integral number of full cycles of the taxable amount of the repeatedly occurring pattern of said portion from said total amount of sales,
• means responsive to an output from said storage means and an output from said deducting means for determining a first imposable tax corresponding to the remainder of said total amount of sales after said deducting therefrom by said deducting means,
• means responsive to an output from said storage means and an output from said deducting means for multiplying the imposable tax amount for a full cycle of the repeated pattern of said portion by said largest possible integer number of full cycles of the repeated pattern for providing a second corresponding sales tax imposable upon said integer number of full cycles of the taxable amount for the repeated pattern in said portion, and
• means responsive to an output from said determining means and an output from said multiplying means for adding said first and second imposable tax amounts and providing as an output the total amount of sales tax imposed upon said taxable total amount of sales.