Fare Computer

The present invention relates generally to an electronic fare computer, usable, for example, in a taxi, for calculating the fare for use of the taxi, displaying the fare as it accrues and displaying a visual representation of substantially each charge contributing to the accrued fare. The invention is particularly suited for use in locations in which the taxi fare is based on zones of travel rather than on total miles travelled. The fare computer might also be utilized in other situations in which a charge is based on the number of zones through which travel occurs rather than on mileage, as for example could be done in carrying freight. The fare computer of the invention is particularly adapted for accepting data indicative of a zone containing the point of origin for hired travel and a zone containing the point of destination, displaying visual representations of such zone or zones to the passenger, and computing and displaying the fare. The invention also relates to a method of calculating and displaying each charge contributing to the accrued fare so that the passenger can immediately know the accrued fare and the manner of calculation thereof.

Fare meters adapted to register a plurality of charges which contribute to the total calculated fare have been of great value to taxi operators and others for automatically calculating such fare. U.S. Pat. No. 3,983,378 discloses a fare measurer including means for counting electrical impulses proportional to either the speed of the vehicle or the time during which the vehicle remains motionless, i.e. waiting time. The pulses indicative of distance travelled or waiting time are transmitted to a binary multiplier wherein the taxi operator selects a multiplication factor by means of several banks of binary switches to determine the fare in accordance with lawful tariffs in the locality. Additional binary switches are provided to enable the fare measurer to register secondary charges such as the number of passengers, baggage handled, elapsed waiting time or special fare rates depending upon, for example, location or time of day. The fare is then automatically calculated and the total fare displayed to the operator by a digital display.

U.S. Pat. No. 3,843,874 shows a taxi meter having pushbuttons for registering the costs of additional services and charges such as the handling of trunks or the paying of bridge and tunnel tolls. Each pressing of a pushbutton increments a fare display be a preselected amount. The patent suggests that where each pressing of the button registers a further charge of ten cents, a 50 cent bridge toll would require five such depressions to provide a visual record of the additional amount to be collected from the passenger at the conclusion of the trip.

The fare measurer of U.S. Pat. No. 3,843,874 further suggests the use of pushbuttons to enable selection of one of four particular tariff schedules, one of which might depend upon the number of zones through which the taxi passes. Nevertheless, the patent discloses the determination of the fare based on the number of impulses counted from a pulse generator operating in response to the distance travelled; the pushbuttons merely select the desired one of a plurality of frequency divider outputs. The operator adds the fare calculated from the selected tariff schedule to the additional services cost to arrive at a total fare charged to the customer.

These types of electronic faremeters automatically perform the calculation of the fare in response to the charges entered therein by the operator and then merely display numerical representations of the fare derived from the charges. Such units display only information relating to cumulative totals such as the total fare or subtotals of the fare resulting from, for example, the distance travelled or the number of bags and trunks carried during the hired travel. Thus, the passenger is often unable to ascertain which and how many charges were added to arrive at the total fare. Indeed, in some situations, not even the total fare is in view of the passenger and thus the passenger is not made aware of it until the destination is reached.

Prior art taximeters are further seen to lack particular adaptation to fare calculation for hired travel within a zone tariff schedule locality wherein the fare meter receives data indicative of a zone containing the origin of the travel and a zone containing the destination of the travel. To be completely effective such a zone-adapted fare meter must also be quickly and simply adaptable to calculate fares based on alternative tariff schedules.

The fare computer of the present invention overcomes the shortcomings of taximeters known to prior art. The invention relates to an electronic fare computer for calculating and displaying accrued fares, and particularly for generating visual displays representing substantially each charge contributing to the accrued fare during the hired travel and the total fare at the end of the travel. Throughout the hired travel, the current accrued fare is displayed along with such visual representations in such a way as to show the passenger the manner in which the total fare is calculated. The fare computer of the present invention is particularly suited for zoned tariff localities wherein a primary, or possibly the only, charge contributing to the total fare is calculated from the number of zones crossed during the hired travel. Alternatively, the fare computer is adaptable to operation on a pure hourly basis or even a distance/time tariff basis, depending upon locality and terms of the hire.

The fare computer of the present invention is completely adapted to be operated within a vehicle such as a taxi from the vehicle's power supply. The fare computer is preferably an entirely electronic solid state, integrated unit to calculate and display a visual representation of substantially each charge contributing to the fare. It permits fare computations with any of a plurality of pre-programmed tariff bases as authorized by the laws or regulations of a given locality and adjacent or surrounding localities. Means are provided to prevent the erroneous entry of fare charge data, and the present fare computer further includes means for preventing fraudulent calculation of a fare.

Alternatively, the fare computer of the present invention is suitable for rate calculations applicable in the trucking or like long distance transportation industries.

The fare computer includes operator actuated input means for registering or accepting a selected tariff schedule such as a zone tariff schedule or an hourly rate schedule. In the ZONE TARIFF MODE, the operator input means further accepts or registers primary charge data representative of the zone containing the origin of the hired travel and the zone containing the destination of the hired travel, as well as secondary charge data representative of all other contributory charges such as the number of suitcases, the number of trunks, the number of pets, rush hour surcharges and elapsed waiting time. In an HOURLY RATE MODE, corresponding to, for example, limousine or sight-seeing service, the fare computer accepts primary charge data representative of the time under hire and limited secondary charge data.

A processing circuit receives the selected tariff schedule and fare charge data and computes an accrued fare therefrom. The processing circuit communicates with a first memory for permanently storing a predetermined compilation of data and a second memory for temporarily storing data transmitted thereto by the processing circuit. In the preferred embodiment, the compilation stored in the first memory includes an operating program for the processing circuit and rate tables containing values for each fare charge received by the processing circuit for calculation of the accrued fare rate. Thus, the tariff schedule and fare charge data are received from the taxi operator by the operator-actuated input and are transmitted to the processing circuit. The fare charge data are then used by the processing circuit to calculate the accrued fare from permanently stored values for the particular tariff and the contributing fare charges selectively entered by the operator.

The inventive apparatus also comprises a display scanner/controller connected to the processing circuit for controlling a digital display and sensing input data conditions at the operator input. The display scanner/controller includes a display sensing element for sensing inputs and a multiplexing element for selectively providing appropriate visual displays.

These and other aspects and advantages of the present invention are more apparent from the following detailed description and claims, particularly when considered in conjunction with the accompanying drawings in which like parts bear like reference numerals. In the drawings:

FIG. 1 is a plan view of a fare computer in accordance with a preferred embodiment of the present invention and particularly shows the displays and the input controls; and

FIG. 2 is a block diagram of the circuitry of a fare computer in accordance with a preferred embodiment of the present invention.

FIGS. 1 and 2 illustrate a preferred embodiment of the present invention. Fare computer 10 is packaged in a housing 12 having a front display/control panel 14. All controls and displays for the fare computer are arrayed to be available at panel 14.

Display/control panel 14 includes at its central portion a map 16 showing the locality of primary operation divided into a plurality of zones, collectively indicated by reference number 18 and individually denoted by the numbers 1, 2, 3, 4 and 5 respectively. Zones 18 may, for example, have border lines 20 corresponding to city streets as shown in FIG. 1. Alternatively, zones 18 may be defined according to any law or regulation governing tariffs in the locality. As illustrated by map 16, each individual zone 1, 2, 3, 4, or 5 can be further divided into subzones generally noted by reference number 22 and individually denoted by the zone number followed by a letter A through H. Thus, each zone 18 shown on map 16 is divided into several subzones 22, each of which is provided with a particular designator, such as subzone 1A or 3E.

Map 16 also includes in one-to-one correspondence with each subzone 22, a light emitting diode or LED 24. LEDs 24, as will be discussed infra, are activated by means of a series of zone select controls 26 and a series of subzone select controls 28. As seen from FIG. 1, controls 26 and 28 may conveniently be embodied in the form of pushbutton switches or keys. Depression of a desired zone select control 26 and a subzone select control 28 actuates the LED 24 in the particular corresponding subzone 22 on map 16, thereby identifying that subzone to the viewer.

In the preferred embodiment, zone select controls 26 are labeled "1", "2", "3", "4" and "5" and include five pushbuttons or keys corresponding to each of the five zones 18 designated 1, 2, 3, 4 and 5 on map 16. Likewise, subzone select controls 28 are labeled "A"; "B"; "C"; "D"; "E"; "F"; "G"; "H" to correspond with the defined subzones 22. Thus, in the preferred embodiment, the point of origin for a hired travel is indicated by first depressing the zone key 26 and then the subzone key 28 corresponding with the subzone of origin to activate the LED 24 indicating that particular subzone 22 on map 16. Next the zone key 26 and subzone key 28 indicating the subzone of the intended destination are depressed, activating the LED 24 indicating that subzone on map 16. These LEDs then provide a visual display of the points of origin and destination to the passenger. Preferably, the LED indicating the origin subzone is continuously activated while the LED corresponding to the destination subzone is intermittently activated, i.e. blinking on and off, so that the passenger can easily distinguish the respective subzones containing the origin and the destination of the hired travel. If the origin and destination are within the same subzone, then a single LED 24 is activated, and it can be either continuously or intermittently activated.

Those skilled in the art will appreciate that both the zone selecting controls 26 and the subzone selecting controls 28 may comprise illuminating switches which illuminate upon depression, either continuously or intermittently as appropriate, to indicate to the passenger the origin and destination indications which have been entered into fare computer 10. In such an embodiment, map 16 and LEDs 24 could be omitted from display/control panel 14, if desired.

Reset control 30, also shown as a key or a pushbutton switch in FIG. 1, is provided to extinguish all activated LEDs 24 on map 16 at the conclusion of the hired travel or, for example, after an inadvertent entry of origin or destination data. Following activation of the reset control 30, fare computer 10 is reset and thus is prepared for entry of new fare data.

Accrued fare display 32 is a four-digit display, preferably made up of four seven segment display elements, for displaying the fare, as it accrues, to both the operator and the passenger. As is evident, display 32 may comprise a LED, LCD or like seven segment display element. Upon completion of the hired travel, fare display 32 presents the total fare. In the ZONE TARIFF MODE of operation, fare display 32 initially displays a primary fare charge determined from the number of zones to be crossed in travelling from the origin point, the zone of which is indicated by a continuously lit LED 24 on map 16, to the destination point, the zone of which is indicated by the blinking LED 24. This component of the total fare is calculated as prescribed by law or regulation to depend on the number of zones to be traversed during the hired travel and is displayed after the origin and destination zones have been entered via pushbuttons 26 and 28. The derived primary fare charge is displayed as a dollar amount at fare display 32 for the benefit of the passenger and the operator.

Alternatively, if the hired vehicle is to be operated in a locality having a tariff schedule other than the zone schedule detailed above, for example a time/distance fare schedule, fare computer 109 may be adapted in ways well known to those skilled in the art to include switching means (not shown) for causing fare display 32 to display the fare as it accrues according to distance travelled during the hire. Such an embodiment of the present invention would further display the fare as accruing according to the elapsed time that the hired vehicle remains motionless or proceeds below a predetermined speed. Thus, fare computer 10 may operate in the manner of conventional electronic fare meters by conventional pulse-counting techniques.

Secondary charge select controls 34, 36, 38, 40, 42, 44, and 46, also shown in FIG. 1 as pushbutton switches, bear respectively the legends "NO. PASS" (number of passengers); "P. SERV" (personal services); "BAGS"; "SUIT CASES"; "TRUNKS"; "STOPS"; and "PETS". Controls 34, 36, 38, 40, 42, 44, and 46 are respectively associated with corresponding seven segment display elements 48, 50, 52, 54, 56, 58, and 60. Each seven segment display 48-60 may be an LED, LCD or like display for providing a digital representation thereon. In the preferred embodiment, each of the displays 48-60 is operated independently of the remaining displays. Each time one of the controls 34-46 is depressed, the corresponding one of the display elements 48-60 is incremented to indicate the associated secondary charge units added to the accrued fare. Thus, for example, where the operator charges for carrying three suit cases, control 40 labeled "SUIT CASES" is depressed three times to successively increment element 54 immediately adjacent control 40 to display the digit "3", indicating that an appropriate charge for three suitcases has been added to the accrued fare appearing at fare display 32. Likewise, if the passenger requests that a number of stops be made during the hired travel, the operator depresses "STOPS" control key 44 the corresponding number of times to increment the display at element 58 to reflect the number of stops made and to add the charges therefor to the accrued fare presented at display 32. Personal services control 36 might be operated to register a secondary fare charge, for example, whenever a request by the passenger requires the vehicle operator to leave the confines of the hired vehicle.

Remaining secondary charge controls 64, 66, 68 and 70 also shown as comprising push buttons or keys bear the legends "TEL." (telephone); "WAIT" (waiting time); "HR." (hourly rate); and "ELAPSED TIME". Controls 64, 66, 68 and 70 are associated respectively with LEDs 65, 67, 69, and 71. Operation of any of the controls 64-68 activates the associated LED 65-71 and adjusts the accrued fare displayed at display 32. If the taxi is picking up the passenger at a designated location in response to a telephone call to the taxi dispatcher, for which an additional charge is made, TEL control 64 is depressed to activate LED 65 and add the additional charge to the accrued fare shown on display 32. In the preferred embodiment telephone control key 64 may be depressed only once during any one hired trip, since the taxi is responding to a single telephone call. Alternatively, if it is the operator's experience that more than one telephone call is sometimes involved, it is a relatively simple matter to those skilled in the art to adapt fare computer 10 to admitting data for more than one call.

"WAITING TIME" control 66 causes fare charges to accrue while the vehicle is under hire by the passenger but temporarily remains stationary. Accrual of the fare is shown by periodic increases in the fare displayed at digital display 32. Digital clock display 72 is made up of four commonly controlled seven segment elements. Clock 72 normally shows the time of day, but by depressing "ELAPSED TIME" control 70 may be made alternatively to display the time elapsed since "WAITING TIME" control key 66 was depressed. Manipulation of "ELAPSED TIME" control 70 causes clock 72 to display the elapsed waiting time until a subsequent depression of control 70 returns the display of clock 72 to that of the time of day. Alternatively, clock 72 can display the elapsed waiting time so long as "ELAPSED TIME" control 70 is held in its depressed position, with clock 72 returning to the display of the time of day when control 70 is released.

As should be evident to one skilled in the art, any additional secondary fare charges authorized by law may be included, along with the associated controls and indicators at display/control panel 14.

Depression of HR. RATE key 68 places fare computer 10 in an HOURLY RATE MODE which disables zone select controls 26, subzone select controls 28, LEDS 24 and controls 34, 38-46, 64 and 66. In the HOURLY RATE MODE, fare computer 10 calculates the fare strictly on the basis of a primary fare charge depending upon the time elapsed while the vehicle is under hire and any secondary fare charges arising from personal services performed by the operator during the hire. In this way fare computer 10 is adapted to calculate, for example, the fare for limousine or sight-seeing services.

In the HOURLY RATE MODE, depression of "ELAPSED TIME" control 70 causes clock 72 to display the elapsed time during which the vehicle has been hired at an hourly rate. All the while, fare display 32 presents the fare as accrued according to the time during which the vehicle has been under hire plus any accrued secondary charges. Thus the passenger is presented with the elapsed time under hire and the fare charge for that time, so that the hourly rate can be simply calculated from the accrued fare divided by the time elapsed. Subsequent depression of control 70 likewise returns clock 72 to displaying the time of day.

Subsequent depression of "HOURLY RATE" control 68 terminates the HOURLY RATE MODE and returns fare computer 10 to operation in the ZONE TARIFF MODE. At any time clock 72 is made to display elapsed time either while waiting in the ZONE TARIFF MODE or the in HOURLY RATE MODE, an elapsed time display indicator 71 is activated.

LED indicators 76, 78, 80, 82, 84, 86 and 88 indicate the day of the week, Sunday through Saturday, and are automatically activated on the appropriate day. A system clock for the preferred fare computer 10 operates on an annual cycle and thus provides an indication of the day of the week at LEDs 76-88 and in addition displays the date at date display 90 in the form of paired digital displays 92, 94 and 96 indicating, respectively, the month, day and year. If fare computer 10 is programmed to recognize holidays, when different fare rates might be in effect, LED indicator 74 can be energized on such holidays. PM indicator 98, which can be an LED, is activated to indicate that the time displayed on clock 72 is afternoon and is extinguished during morning hours. Also, rush hour indicator 100 is provided to apprise the passenger that a rush hour fare, such as a surcharge to the accrued fare, is in effect and has been added to the fare presented at fare display 32.

With reference to FIG. 2, fare computer 10 includes a processing circuit 200 including a microprocessor 202 and an input/output (I/O) unit or interface unit 204. I/O unit 204 interfaces between processor 202 and system clock 206. As further discussed infra, processing circuit 200 reads and is synchronized over bus 207 by real time and system clock 206. Processing circuit 200 also includes an internal clock (not shown) for synchronizing communication between processing circuit 200 and the remaining elements of fare computer 10. Clock 206 receives primary power from the vehicle battery 208 through power supply filter 210. Backup or secondary power is provided in the event of failure of battery 208 by a backup power source (not shown) which is preferably included with filter 210. Such a back-up source could comprise a 3 volt Lithium battery. Clock 206, which may be sensitive to wide variances in temperature occurring when, for example, the vehicle is unoperated for extended periods, is preferably shielded by encapsulation within a power resistor (not shown) to maintain clock 206 above 32.degree. F. In cold weather the power resistor-heater is connected to receive power from vehicle battery 208 or an auxiliary power source (not shown) within filter 210 in any way known to those skilled in the art.

Processing circuit 200, which includes a stored programmed control, is also connected via bus 212 to external memory unit 214 and to display scanner/controller 216. Processing circuit 200 selects from memory 214 or display scanner/controller 216 through address selector 218. As a further apparent from FIG. 2, address selector 218 is made to select particularly from between read only memory (ROM) 220 and random access memory (RAM) 222, both within external memory unit 214. Processing circuit 200 communicates with memories 220 and 222 either directly over bus 112 or indirectly through demultiplexor 224.

ROM 220 permanently and unalterably stores the main programs used by processing circuit 200 for calculating fares. ROM 220 permanently stores, for example in a look up table, a value for each particular fare charge corresponding to a hired travel from any subzone 22, constituting the point of origin, to any subzone 22, constituting the point of destination, for all such subzones 22 depicted on map 16. Microprocessor 202 merely looks up the appropriate value for such primary fare charge in ROM 220 whenever the subzones 22 containing the origin and the destination of hired travel are provided by means of selecting controls 26 and 28. ROM 220 likewise permanently stores representations or values for each secondary charge resulting from the depression of control keys 34-46, and each charge accruing as a result of operation of control keys 64-68. Thus, since fare computer 10 relies exclusively on ROM 220 for all fare rate data, as well as for the programs calculating the total fare, fare commputer 10 is protected from tampering to fraudulently alter the rates. Unauthorized tampering with the fare rates is prevented as ROM 220, by definition, is only readable by processing circuit 200. Thus, changing of fare rates or schedules can be effected only by authorized substitution of ROM 220 with a like unit having applicable new rates permanently stored therein.

RAM 222 stores on a temporary basis all fare charge data received by fare computer 10 during a hired travel. RAM 222 further stores the instantaneous accrued fare during the hired travel.

Communicating with memories 220 and 222, as well as with processing circuit 200 over bus system 212, scanner/controller 216 includes display scanner 226 and display multiplexer 228. In response to signals from processing circuit 200, display scanner/controller 216 drives the various displays of display board 230 corresponding to display/control panel 14. By means of display scanner 226, scanner/controller 216 also receives hired travel data from any of the control keys mounted on board 230.

In the preferred form, display scanner 226 includes internal random access memory (not shown) for temporarily storing fare charge data entered at display/control panel 14. Scanner 226 is programmable to have a particular scan rate such as 100 KHz to perform full scans of all control keys approximately every 10 microseconds. Upon scanning and storing entered fare charge data, scanner 226 provides a signal indicative of a change in state corresponding to entry of any fare charge data at control/display panel 14. Scanner 226 is responsive to system clock 206 for timing but executes programmed scan cycles independent of processing circuit 200. Thus, for instance, zone select keys 1, 2, 3, 4, and 5 are scanned first by scanner 226, followed by scanning of subzone select kyes A, B, C, D, E, F, G AND H to receive hired travel data for application into the internal memory of scanner 226.

An obvious alternative to the preferred scanner 226 would be a device for interrupting processor 202 upon sensing the entry of tariff schedule or fare charge data at panel 14. In such an embodiment, a processor 202 then would execute a specified interrupt routine to receive the data from such scanning device.

To effect calculation of the appropriate fare on fare computer 10, the vehicle operator selects from either the ZONE TARIFF MODE, by simply entering origination point data at zone and subzone select controls 26 and 28, or the HOURLY RATE MODE, by depressing "HOURLY RATE" control key 68. When fare computer 10 is operated in the ZONE TARIFF MODE, the driver first receives information regarding the destination of the hired travel from the passenger. Origin and destination data pertaining to the particular zones 18 and subzones 22 are entered at display/control panel 14. Note that the origin and destination data do not indicate the exact location of origin and destination but only the selected subzones. Thus, the fare is made up of a primary contributing charge, depending upon the number of zones traversed during the hired travel, plus secondary charges designated by the various control keys 34-70.

Those skilled in the art will appreciate that fare computer 10 need not be limited to the particular zone and subzone arrangement depicted by map 16. Indeed, ROM 220 may be made to store any zone and subzone arrangement. Thus, fare computer 10 is adaptable to localities having a greater or a lesser number of zones and/or subzones, or simply zones with no subzones, all independent of the area thereof. Thus, by way of example, when the vehicle is hired anywhere within subzone 3E on map 16, the vehicle operator enters data providing the origin of the hired travel by first depressing the zone select control 26 labeled "3", then depressing the subzone select key 28 labeled "E". Display scanner 226, performing continuous scanning of all input controls of panel 14, senses operation of the appropriate zone and subzone select keys 26, 28 and internally stores data representative of subzone "3E". Microprocessor 202 periodically executes supervisory interrogations of scanner 226 for any changes in state indicated thereby. Such a change in state is effected when the origin data, "3E", is sensed and stored by scanner 226. Microprocessor 202 responds to the change in state indicated by scanner 226 by executing a directed interrogation of the internal memory (not shown) of scanner 226 in order to determine the particular zone and subzone data entered at panel 14. At the same time, microprocessor 202 enables RAM 222 by means of address selector 218 so that the origin data can be received by both microprocessor 202 and RAM 222 over bus 212. Having received the data from scanner 226, processor 202 first terminates the write cycle for storing this data in RAM 222 and next interrogates ROM 220 for the address of the LED 24 corresponding to subzone 3E. Upon receipt of the appropriate address, microprocessor 202 transmits the same over bus 212 to display multiplexor 228 to activate the LED 24 within subzone "3E" on may 16.

In the same way, after the operator has been told the desired destination by the hiring passenger, the operator determines the subzone 22 containing the destination, for instance subzone "1B", and enters that subzone indication at panel 14 by successive depression of the zone select key 26 labeled "1" and the subzone select key 28 labeled "B". Display scanner 216 likewise transmits the appropriate signals to processing circuit 200 over bus 212, during direct interrogation by processor 202. Processor 202 in turn, reads from ROM 220 to find the address of the LED 24 corresponding to subzone "1B" and provides such to scanner/controller 216. RAM 222 also receives such destination data for subsequent use in determining the fare charge for travel from subzone "3E" to subzone "1B".

It will also be understood by those skilled in the art that scanner/controller 216 may independently cause activation of origin and destination designating LEDs 24 either prior to or concurrent with transmitting the corresponding origin or destination data over bus 212 to processing circuit 200. Alternatively, display/control panel 14 could comprise conventional switching circuits for automatically activating an appropriate LED 24 upon operation of zone and subzone select controls 26 and 28. The origin and destination data would likewise be sensed upon the next subsequent scan by scanner 226 for transmittal over bus 212 upon interrogation by processing circuit 200.

Fare computer 10, in the preferred form, includes a built-in error protection feature should the operator inadvertently enter, for example, a nonexistent subzone for either an origin or destination point. When such erroneous data is entered at display/control panel 14, processing circuit 200 executes an error indicating routine stored in ROM 220 to cause each LED 24 on map 16 to blink intermittently until the operator resets fare computer 10 by operating "RESET" control 30.

Normal operation continues with processor 202 interrogating RAM 222 to read the stored origin and destination data. Processor 202 receives the data and performs a "look-up" routine to locate the primary fare charge for travelling from subzone "3E" to subzone "1B" in the permanently stored rate tables of ROM 220. Processor 202 retrieves the proper value from ROM 220 and transmits signals representative of such charge over bus 212 to display multiplexer 228 for activation of digital fare display 32. While transmitting the primary fare value data over bus 212, processor 202 also executes a write cycle to cause RAM 222 to receive and temporarily store the accrued fare data. Multiplexer 228 causes fare display 32 to display that primary charge contributing to the total fare which corresponds to a hired travel between the selected subzones "3E" and "1B". The fare charge is displayed at fare charge display 32 to the passenger and to the operator.

To continue the exemplary explanation of the operation of fare computer 10, suppose that two passengers having a number of suitcases, a dog, and a trunk board the hired vehicle to travel from subzone "3E" to subzone "1B". Once the fare charge corresponding to travel from origin "3E" to destination "1B" is shown by fare display 32, the operator adjusts the fare to account for secondary charges corresponding to an extra passenger, a pet, and the particular types of luggage carried. Thus, for the second passenger, the operator depresses control key 34 labelled "NO. PASS." to increment element 48 of matrix 62 to show the number "2" corresponding to the second passenger. The signal generated by depression of control key 34 is sensed by scanner 226, and data indicative thereof is transmitted to processor 202 as previously described. Processor 202 interrogates ROM 220 for signals representative of the value corresponding to a secondary fare charge for the second passenger. Processor 202 receives the data from ROM 220, and performs an addition of the secondary charge corresponding to a second passenger and the subzone-to-subzone primary charge to arrive at an accrued fare charge accounting for the second passenger. Processor 202 then effects storage of the newly calculated accrued fare in RAM 222 and display of that fare by means of multiplexer 228 and display 32.

In the same way, processing circuit 200 receives secondary charge data indicative of the dog and the number of suitcases and trunks carried aboard, in the order that such data is entered at control keys 46, 40 and 42 respectively. Processing circuit 200 accordingly causes appropriate incrementation of each of display elements 60, 54 and 56 and executes successive addition sequences while communicating with external memory 214 to arrive at a total fare for the travel. The fare is then displayed at fare display 32.

Likewise, depression of the remaining fare charge control keys 36, 38, and 44 increments each corresponding element 50, 52, and 58. These corresponding elements are each initially blank and do not display a one as dose element 48 prior to entry of further fare charge data. Alternatively, all of display elements 50-60 may be made to display a zero prior to the entry of any fare charge data.

For operation during rush hour, fare computer 10 indicates that rush hour rates are in effect by means of LED 86. In the preferred operation of fare computer 10, processor 202 is programmed to interrogate ROM 220 for a rush hour surcharge during predetermined daily periods of unusually heavy traffic. Then during rush hours, display 32 is made to show the appropriate surcharge before any further fare charge data are entered to apprise the passenger of the exact portion of the total fare contributed by the rush hour surcharge.

When "WAITING TIME" control key 66 is depressed, as when the hired vehicle arrives at an origin point but must remain stationary until the passenger boards the vehicle, processor 202 begins to count pulses from system clock 206. Upon counting a preselected number of such clock pulses, processor 202 effects addition of a preselected value stored in ROM 220 to the fare charge displayed at display 32. A counter (not shown) within processor 202 resets and repeats the cycle to increase the fare by further waiting time charges as necessary. All the while, processing circuit 200 causes activation of LED 67 to remind the passenger that fare computer 10 has been calculating a waiting time fare charge.

In the preferred fare computer 10, microprocessor 202 is programmed to have a preselected maximum allowable waiting time after which fare increases attributed to "waiting time" are no longer calculated. Another feature of the preferred form is a preset period between consecutive operations of WAITING TIME control 66 before processor 202 will cause increases in the fare corresponding to depression of control key 66. This preset period may be set at, for example, three minutes or any time which, while not unduly burdening the operator, is likely to prevent subsequent activation of the "WAITING TIME" control before the next hiring of the vehicle to ensure against defrauding the next passenger.

Where the vehicle is hired for limousine or like service at strictly hourly rates, fare computer 10 is placed in the HOURLY RATE MODE. In this mode, processing circuit 200 disables function control keys 34, 38-46 and 64-68 in any known way as by disabling the scanning functions of scanner/controller 216 with respect to those keys or by programmed instructions causing processor 202 to disregard all signals representative of operation of those controls. In the HOURLY RATE MODE, the primary fare charge is calculated by processor 202 as a function of the elapsed time in that mode multiplied by the particular hourly rate value stored in ROM 220. Up to nine secondary charges for "personal services" may be added to the accrued hourly fare by means of "P. SERV" control key 36. When "P. SERV." control key 36 is depressed, a corresponding display element 50 is incremented to identify the number of personal services performed by the driver during the hire. Personal services data is received by processor 202 from scanner/controller 216, so that corresponding secondary fare charges can be added to the time-accrued fare by processor 202 and in turn displayed at fare display 32.

The preferred embodiment of the fare computer as shown in FIG. 2 may be implemented using an Intel 8085 single package microprocessor as processor 202. The 8085 microprocessor preferably is provided with a four MHz crystal serving as an internal clock, while real time and system clock 206 preferably comprises a 32.768 KHz real-time clock. An assembly language program, suitable for permanent storage into ROM 220, for controlling the operation of the 8085 microprocessor in calculating the accrued fares and in displaying all fare charges is as follows: ##SPC1##

Although the present invention has been described primarily with reference to a preferred embodiment, rearrangement and modifications may be made by one skilled in the art within the scope of the invention.