Time Logging Apparatus

The present invention relates generally to time keeping apparatus, and more specifically to apparatus requiring minimum operator attention for monitoring, displaying and facilitating the making of a written record of time chargeable to a plurality of accounts.

The keeping of time chargeable to individual accounts or tasks of interest has long been a necessary but burdensome chore. Time records are important for a variety of purposes, of which one of the more obvious is providing a basis for billing for professional services. In the context of a modern, professional office, the time keeping chore has become increasingly important because of increasing pressure to maximize the amount of billable time. This objective requires keeping accurate time records, of which one facet involves recording small amounts of time involved in the telephone consultations and other brief tasks for a client, patient or customer. Contributing to the burden of keeping time records is the fact that a day's activities frequently involve services for a significant number of clients, patients or customers, and that the total services for any single client during a day's time may be scattered throughout the day.

Many time record keeping aids have been devised and are known. These range very simple devices for facilitating manual monitoring and recording of only the most basic data, to very elaborate computerized systems permitting the monitoring, entry, manipulation, storage and retrieval of a vast amount of data directly or indirectly related to the time keeping task.

Regardless of the type of time keeping device or system, it is generally necessary to manually enter one or more catagories of information or data. At best, such manual processes require some attention and effort, and are a distraction from the primary duties of the professional. As a result, the entry of time keeping data tends to be postponed or neglected, and data inaccurately entered or data on significant blocks of time entirely omitted. Further, neglect, inaccuracies and omissions tend to increase directly with the complexity of the required entries and entry format. However, it is also true that more complete time records generally require more extensive entry of data.

In order to avoid many of the problems associated with previously known time record keeping aids, the applicant has devised a unique compact microprocessor based time logging system having substantial capabilities, and characterized by an exceptionally simple data entry and retrieval format. Function instructions and account information are entered with a maximum of two key actuations on a simple and understandable keyboard. Accordingly, minimum attention and effort are required, thus encouraging prompt and accurate time keeping practices.

Time logging apparatus in accordance with the present invention basically comprises memory means for storing counts of clock signals respectively corresponding to periods of time chargeable to each of a plurality of accounts, each account having an account switch associated therewith. Microprocessor means operating under program control responds to a single actuation of an account switch by causing subsequent clock signals to be accumulated only for the account associated with that switch. Display means is provided for displaying a time interval corresponding to the count in the memory means for a selected account, the display means being activated by the microprocessor means in response to sequential actuation of a first function key and an account key. Additional storage means may be provided for accumulating of clock signals at an accelerated rate, and, in response to sequential actuation of a second function key and an account key, to add its stored count to the count for the selected account. Further, the microprocessor means may be programmed to cause the additional memory means to accumulate a count at a rate which increases with time, and to provide for optional display modes whereby fractional hours of time are displayed in minutes or in hundredths of an hour.

FIG. 1 is a pictorial view of a time logging device in accordance with the applicant's invention;

FIG. 2 is a block diagram of the principal functional elements of the applicant's time logging apparatus;

FIGS. 3A and 3B together comprise a schematic diagram of a particular embodiment of the time logging apparatus of FIGS. 1 and 2;

FIG. 4 is a block diagram showing the organization of principal microprocessor routines performed in the time logging apparatus of FIGS. 1-3;

FIGS. 5A-5I are flow diagrams for the routines identified in FIG. 4; and

FIG. 6 is a flow diagram for one of the subroutines utilized in the routine of FIG. 5A.

In the pictorial view of FIG. 1, reference numeral 10 identifies a cabinet which supports and/or houses the various components making up time logging apparatus in accordance with the applicant's invention. The principal external features comprise a keyboard input panel generally identified by reference numeral 11, a plurality of indicator lamps generally identified by reference numeral 12, a numerical display generally identified by reference numeral 13, a removable card 14, and on-off switch 15 and a display mode switch 16. Keyboard 11 includes a plurality of primary account keys, each associated and aligned with a separate one of indicator lamps 12, the indicator lamps and associated account keys being numbered to identify separate accounts. Keyboard 11 also includes six labeled function keys.

The top face of cabinet 10 may be designed with a slot (not shown) located as indicated by reference numeral 17 for permitting card 14 to be inserted and removed. Card 14 includes a plurality of blank spaces for accommodating a written record of account names and time chargeable to each account. Card 14 is arranged so that when it is in place, each blank space thereon is aligned with a separate primary account key and associated indicator lamp.

The six function keys, whose purpose will hereinafter be described in detail, are labeled "TOTAL", "IDLE", "READ", "CLEAR", "ADD", and "START-STOP". Display mode switch 16 permits selection of either of two display formats, whereby a time interval is displayed in either hours and minutes or hours and hundreds of an hours.

The following is a brief description of external operation of the applicant's time logging apparatus. The embodiment shown in FIG. 1 is designed to facilitate the monitoring and recording of time chargeable to any of ten separate accounts. Initially, a card 14 is inserted through a slot at 17 into a holder in the top face of cabinet 10. The names of up to 10 accounts may be noted in the spaces provided on card 14. The time logging apparatus is set in operation by positioning switch 15 in its ON position. Thereafter, until switch 15 is turned OFF, all time is charged to one of the primary accounts or to an idle account. From the time switch 15 is turned ON, and until one of the primary account switches is depressed, time is charged to the idle account. The time in any account remains until cleared, and is not altered by turning switch 15 OFF.

To start charging time to a primary account, the account key associated with the selected account is momentarily depressed. The account to which time is being charged is indicated by illumination of the indicator lamp associated with that account. The active account may be changed simply by momentarily depressing the key associated with a newly selected account, at which time its indicator lamp will illuminate and time thereafter will be charged to that account. There may be time intervals which are not chargeable to any of the primary accounts. Charging of time to a primary account can be interrupted by momentarily depressing the START-STOP key, which causes time thereafter to be charged to the idle account. Depressing of the START-STOP key a second time returns charging of time to the primary account previously being charged.

The READ function key is used to display the time in a selected primary account. The display function is accomplished by depressing the READ key and, within four seconds, depressing the account key for the selected account. As long as the account key is depressed and for four seconds thereafter the associated indicator lamp will flash and the desired account total will be displayed. The TOTAL function key is used to display the sum of the times in all primary accounts. Time in the idle account is displayed by depressing the IDLE key.

The CLEAR function key is used to clear the times from any selected account or all accounts. The clearing function is accomplished by depressing the CLEAR key and within four seconds, depressing a selected primary or IDLE account key or the TOTAL key.

The ADD function is used to add time to any selected primary account. When the ADD key is depressed, the display counts up from 0 at a rate which increases with time. Counting commences at an initial rate, and the counting rate increases as long as the ADD key is continuously actuated, except that the counting rate will not exceed a predetermined maximum rate. After the ADD key is released, the last number displayed will be held in the display for four seconds unless either the ADD key or a primary account key is depressed. If the ADD key is again depressed within the four second interval, the display will start counting up from its present value, again at a rate which commences with the initial rate and increases with time. If a primary account key is depressed within the four second interval, the time on the display will be added to the time already in the selected account. As long as the account key is depressed, and for four seconds thereafter, the associated indicator lamp flashes and the added time is displayed.

As is apparent from the foregoing operational description, the applicant's time logging apparatus is exceptionally simple to understand and operate. Further, it offers considerable functional flexibility and provides most generally needed time keeping information in an exceptionally understandable format. These and other benefits are achieved through the use of microprocessor based apparatus whose general structure will be described in connection with FIG. 2.

In FIG. 2, reference numeral 20 identifies a conventional primary source of alternating electric current, such as conventional 60 cycle per second current from a public utility. The voltage provided by source 20 is reduced and isolation accomplished by means of a transformer 21 whose output is furnished to a power supply 22 and a clock 23. In addition to transmitting power from primary source 20, power supply 22 may also contain a battery and associated circuitry for supplying back-up power to prevent loss of data in the event of failure of the primary source. Clock 23 utilizes the fixed frequency characteristic of source 20 to establish a time reference for the time logging apparatus. The time reference from clock 23 and signals from an input panel or keyboard 24 are received by a multiplexer 25 which transmits timing, function and account selection inputs to a microprocessor 26 operating under program control.

The program for microprocessor 26 is contained in a read only memory portion of a memory means 27. Memory means 27 also includes a random access memory portion controlled by microprocessor 26 for storing and supplying time data for each of the plurality of primary accounts and the time to be added to any account through operation of the ADD key. Upon actuation of appropriate function and/or account keys, microprocessor 26 supplies signals to a decoder/latch 28 which causes the time in a selected account or the time accumulated through operation of the ADD key to be displayed on a display 29. For purposes of FIG. 2, display 29 also includes a plurality of account indicator lamps which are driven by decoder 28.

The internal circuitry of the time logging apparatus of FIGS. 1 and 2 is shown in detail in FIGS. 3A and 3B. Reference numeral 30 identifies a source of 60 cycle per second alternating current, such as commonly available from a public utility. The current from source 30 is supplied through a primary winding 31 of a transformer whose secondary winding 32 is connected to ground through a center tap 33. The opposite ends of secondary winding 32 are connected to the anodes of a pair of diodes 34 and 35 arranged to achieve half-wave rectification.

The cathodes of diodes 33 and 34 are connected to the inputs of a pair of commercially available voltage regulators 36 and 37, such as those identified by National Semiconductor Corporation numbers LM341P-5 and LM309K respectively. Voltage regulator 36 supplies electrical power at five volts through a conductor 38 to a random access memory (RAM) and an associated decoder as will be described hereinafter, and also functions to maintain a charge in a battery 39 which is connected between ground and the output terminal of the voltage regulator through a resistor 40. A capacitor 41 is connected across series connected battery 39 and resistor 40. A diode 42 is connected across resistor 40. Voltage regulator 36, battery 39 and the associated circuitry cooperate to ensure continuous voltage on conductor 38 sufficient to prevent the loss of data in the event of failure of source 30 for up to several hours. Reference numerals 43 and 44 identify filter capacitors associated with voltage regulator 37 which supplies operating power for all components except the previously mentioned RAM and decoder.

The time logging apparatus is based on a microprocessor which, in the event of a power failure, must be shut down in an orderly manner. Impending power failure is sensed by circuitry 45, including a zener diode voltage reference 46 and Schmidt trigger circuit 47. The output signal of Schmidt trigger circuit 47 is supplied to the microprocessor through a conductor 49, and is utilized as will be described hereinafter.

A timing signal is derived from the alternating voltage at one end of secondary winding 32 by means of a commercially available timer chip 50 and associated input circuitry 51. One suitable timing device is a Signetics, Inc. 555 Timer which produces a positive going pulse of about fourteen milliseconds duration every sixteen milliseconds. The output signal of timer 50 is supplied to a pair of interconnected NAND gates 53 and 54 which produce a one microsecond negative going pulse every sixteen milliseconds. The latter signal is utilized to set a flip-flop 55 whose output signal appears on a conductor 56. The output signal of flip-flop 55 is set low every sixteen milliseconds, and reset at the same frequency by a strobe signal on a conductor 57.

Reference numerals 60, 61 and 62 identify commercially available eight input multiplexers which accept timing signals from flip flop 55 and input signals from a plurality of switches 52. Suitable multiplexers are manufactured by Motorola, Inc., and designated at Type SN57151. With reference to FIG. 1, switches 52 correspond to the keyboard keys, ON-OFF switch 15 and display mode switch 16. The key switches may be momentary contact switches. One side of each switch is connected to ground, and the other side is connected to a separate data input terminal on one of multiplexers 60-62. Each data input terminal is connected to the output terminal of voltage regulator 37 through a resistor. Accordingly, the multiplexer input terminals are maintained at a high voltage state except when the switches are closed.

The input switch identified by reference numeral 58 corresponds to ON-OFF switch 15. An indicator lamp 59, which may correspond to the lower dot illustrated on display 13 in FIG. 1, is connected between voltage regulator 37 and one side of switch 58. Accordingly, lamp 59 (lower dot in display 13) is lit when switch 58 is closed to turn the time logging apparatus ON.

Multiplexers 60-62 each have a data output terminal labeled "Z". They also each have a strobe terminal labeled "S" and address terminals labeled "ADR" for receiving an address which determines from which input terminal data will be transmitted to the output terminal. The data output terminals are connected through NOR gates 63-65, each having two inputs, a three input NOR gate 66 and a flip-flop 67 to a SENSE terminal of a microprocessor 70. For purposes of the following description, microprocessor 70 is assumed to be a Signetics 2650 Microprocessor which has PAUSE, RESET, CLOCK, address bus (ADR), data bus (DBUS) and read/write (R/W) terminals, in addition to the SENSE terminal.

Interconnected NOR gates 63-66 effectively serve to permit additional addressing so that at any one time only data from a single desired input terminal is passed to microprocessor 70. Three multiplexers and four NOR gates are shown for achieving the multiplexing function only to illustrate one satisfactory implementation. A single multiplexer having more data input and address terminals could be used equally as well.

One input of each of NOR gates 63-65 and the strobe terminal on each of multiplexers 60-62 is supplied with a strobe signal. Specifically, the strobe signal for multiplexer 60 and NOR gate 63 is supplied on a conductor 71. The strobe signal for multiplexer 61 and NOR gate 64 is supplied on a conductor 72. The strobe signal for multiplexer 62 and NOR gate 65 is supplied on a conductor 73. Thus, the strobe signals on conductors 71-73 provide for selectively enabling the multiplexers and, in part, determine which one of switches 52 is permitted to control the state of the signal supplied to the SENSE terminal of microprocessor 70 at any one time. NOR gate 66 provides for interconnecting the output terminals of NOR gate 63-65. Flip-flop 67, which is supplied with a strobe signal on conductor 74, provides for synchronizing the input data, i.e., keeping the signal at the SENSE terminal in its proper state until it can be accepted by microprocessor 70.

The signal on conductor 49 is supplied to the PAUSE terminal of microprocessor 70 through a pair of series connected inverters 75 and 76. Inverters 75 and 76 function to introduce a short delay into the signal on conductor 49 generated by an impending failure of the primary power source. The delayed signal is further inverted by means of an inverter 77 and an associated resistor-diode-capacitor network and supplied to the RESET terminal of microprocessor 70. The signals supplied to the PAUSE and RESET terminals through inverters 75-77 cause operation of microprocessor 70 to be shut down in an orderly manner in the event of failure of the primary power source.

A clock signal for microprocessor 70 is produced by an inverter 78 and an associated resistor-capacitor network comprising a resistor 79 connected between the output and input terminals of the inverter and a capacitor 80 connected between the input terminal and ground. In one satisfactory embodiment, the resistance and capacitance values were chosen to achieve oscillation at a frequency between 600,000 and 700,000 cycles per second. However, the applicant's time logging apparatus is capable of satisfactory operation over a substantially wider range of clock frequencies.

Microprocessor 70 is programmed as will hereinafter be described to generate addresses and maniplate data as required. Address words are supplied over an address bus 82 to multiplexers 60-62, a read only memory (ROM) 84, a random access memory (RAM) 86, a decoder 88, a display driver 90 and a LED driver/latch 92. ROM 84 and RAM 86 are connected to data terminals of microprocessor 70 through a data bus 94. ROM 84 contains the program for microprocessor 70, and, in response to an address on bus 82, supplies a corresponding instruction to the microprocessor over bus 94. A single block labeled ROM is shown for simplicity. However, the ROM may actually be implemented with several identical coordinately addressed ROM chips. Strobe signals supplied over conductors represented by line 95 selectively enable the appropriate chip.

Similarly, in response to an address on bus 82, and strobe signals on conductors represented by line 96, RAM 86 which may be implemented with several RAM chips, stores data from or supplies data to microprocessor 70 over data bus 94. Storing of data in RAM 86 is effected by means of a write signal supplied to the RAM from microprocessor 70 through an inverter 97 and a conductor 98. RAM 86 obtains its power from voltage regulator 36 and/or battery 39 to prevent the loss of stored data in the event of failure of the primary power source. The voltage at the enabling terminal of the RAM is also prevented from unintentionally dropping by connecting the enabling terminal to conductor 38 through a resistor 99.

Decoder 88 is utilized to supply the strobe signals on conductors 57, 71-74, 95 and 96, in addition to supplying strobe signals to display driver 90 and LED driver/latch 92 over conductors 100 and 101 respectively. The strobe signals are generated in response to address words provided by microprocessor 70. Decoder 88 may be implemented with several decoder chips, such as SN74LS138 data selectors/multiplexers manufactured by Texas Instruments, Inc. Power for the decoder is supplied by voltage regulator 36 and/or battery 39 to further insure against loss of data stored in RAM 86.

Display driver 90 responds to address words on address bus 82 and strobe signals on conductor 100 by appropriately activating a four digit display assembly 102. Microprocessor 70 is programmed so that the address words result in displaying of numerals which represent time intervals in accordance with the account and function keys which have been actuated.

Certain output terminals of LED driver/latch 92 are connected to a plurality of indicator lamps 103 corresponding to indicator lamps 12 in FIG. 1. Microprocessor 70 is programmed to supply address words which cause driver/latch 92 to illuminate indicator lamps 103 for those accounts having activity associated therewith at any time. Driver/latch 92 may be implemented with 74LS259 chips manufactured by Texas Instruments, Inc.

Two additional output terminals of driver/latch 92 are connected to circuitry, including transistors 104, 105 and 106, which provides for illuminating an indicator lamp 107 corresponding to the upper dot shown in display 13 in FIG. 1. Lamp 107 is lit when the display mode for displaying time in hours and minutes is selected. Functioning of lamp 107 is coordinated with functioning of display assembly 102 so that when the lamp is lit the proper set of numerals is displayed on the display assembly.

A general organization of the principal routines which microprocessor 70 is programmed to perform is diagrammed in FIG. 4. FIGS. 5A-5I comprise a flow diagram for the principal routines. A program listing of the complete microprocessor program is given Appendix A. The listing contains headings to identify the various sets of instructions corresponding to the routines identified in FIGS. 4 and 5.

Certain blocks in the flow diagrams of FIG. 5A-5I are labeled subroutines. Appendix B contains program listings for the subroutines. FIG. 6 is a flow diagram for subroutine OX, the longest of the subroutines.

As set forth in detail hereinbefore, the applicant has provided improved microprocessor based time logging apparatus. The apparatus is compact, structurally simple, and characterized by an exceptionally simple data entry and retrieval format. In spite of its structural and functional simplicity, the apparatus offers considerable operational flexibility and time data manipulation capability. Although only a single embodiment is shown and described in detail, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the applicant's contemplation and teaching. Accordingly, the coverage sought for the present invention is not limited to the particular embodiment shown, but only by the terms of the appended claims.