WO1985001805A1

WO1985001805A1 - Automated muslim timepiece

Info

Publication number: WO1985001805A1
Application number: PCT/US1984/001612
Authority: WO
Inventors: Nassar Ahmed Ismail; Mahmoud F. Abdel-Rahman; Moustafa Elshafei Ahmed
Original assignee: Nassar Ahmed Ismail; Abdel Rahman Mahmoud F; Moustafa Elshafei Ahmed
Priority date: 1983-10-11
Filing date: 1984-10-10
Publication date: 1985-04-25
Also published as: EP0158674A1

Abstract

A timepiece which keeps traditional western time and which also calculates and presents Muslim obligatory prayer times. In one embodiment the timepiece contains a timing source, a liquid crystal display for displaying traditional western time and individual Muslim obligatory prayer times, and computers for calculating, updating and presenting these times. The timepiece also calculates and displays the direction to Mecca in Saudi Arabia.

Description

AUTOMATED MUSLIM TIMEPIECE

BACKGROUND OF THE INVENTION

This invention relates to timepieces and particularly to an automated Muslim timepiece.

There are approximately 1,000 million people world-wide who practice the Muslim (Islamic) religion in one form or another. A fundamental tenant of the Muslim religion is the obligation to pray five times a day and to face Kabba, a place in the City of Mecca, Saudi Arabia, while praying. Not only must the Muslim pray five times a day but the prayers must be said during particular periods of the day. The five obligatory periods for prayers are: morning twilight (FAJR) to sunrise (SHURUQ), noon (ZϋHR) to mid- afternoon (ASR), midafternoon (ASR) to sunset (MAGHREB), sunset (MAGHREB) to evening twilight (ISHA), and evening twilight (ISHA) to morning twilight (FAJR), all as determined at the geographic location of the person praying. The optimum time for prayer is at the beginning of each prayer period. The time for prayer at any given location is, therefore, determined by the position of the sun with respect to that particular location. The position of the sun in the sky in turn varies with the time of the day,^* longtitude^", latitude, and time of the year.

In those countries with heavy Muslim populations the Muslim usually knows the'start of particular prayer periods by the traditional call for prayers, the "AZHAN". The Azhan is a specific chant and is usually sounded over loud speakers from Mosques. Mosques are numerous and wide spread enough in the Muslim world that most of the Muslim population can hear the call for prayers , the Azhan, at prayer times. The direction to Kabba (Mecca) in relation to each Mosque is known. There are also. available today yearly Muslim prayer calendars which have all the prayer times for a particular year in a given city or country. The make up of the calendar varies from place to place and from year to year.

The present methods of determining prayer times have limitations. Those Muslims not near enough to Mosques to hear the Azhan, especially those living outside traditional Muslim countries, can not determine obligatory prayer times unless a Muslim prayer calendar Is available for their particular location. For the Muslim traveler determination of prayer times is especially difficult because of the geographic dependence of obligatory prayer times. Another problem for the Muslim traveling or living outside of a traditional Muslim area is the Muslim's dependence on the Arabic date for determination of fasting periods and holydays. This is not readily available.

SUMMARY OF THE INVENTION

The present invention overcomes these difficulties by providing a means for determining prayer times which is not dependent on a Muslim's. ability to hear the Azhan called from a Mosque nor his access to a prayer calendar. The present invention comprises a timepiece keeping time in the traditional western fashion but which also has the ability to keep Muslim obligatory prayer times as well as indicate the direction to Kabba (Mecca). The invention has this ability regardless of the physical location of the timepiece. Another feature of the invention is its ability to calculate and display the Arabic date.

Time of day, date, geographic location, i.e., longtitude and latitude, are initially set in the timepiece by means of simple push button switches. The -timepiece then calculates and displays the Muslim obligatory prayer times for one entire day at that particular location and automatically updates and changes the times for subsequent days. Direction to Mecca and Arabic date are also calculated and may be optionally displayed. The process continues indefinitely until one of the initial variables, such as location, is changed. With a change in a variable, - the entire process begins over again.

Accordingly, an object of this invention is to provide an automated Muslim timepiece.

Another object of this invention is to provide a timepiece with mea-ns for keeping and presenting traditional western time, and. which also has the ability to keep and present Muslim obligatory prayer times.

Another object of this invention is to provide a timepiece with the means for determining the direction to Mecca from any given geographic location. Another object of this. nvention is to provide a timepiece with the means fcr determining the current Arabic date.

Another object of this invention is to provide a timepiece with the means for sounding the Azhan.

A more specific object of this invention is to provide a traditional timepiece which includes the means to calculate and display 2-luslim obligatory prayer times for any given location, the direction to Mecca for any given location, and the Muslim (Arabic) ^* day, month and year.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 is a plan view of the display face of a timepiece according to the invention;

FIGURE 2 is a plan view of the entire face plate of the timepiece showing the manual input switches;

FIGURE 3 is a block circuit diagram of a timepiece according to the invention;

FIGURE 4 is a plan view of the display face of the timepiece showing a traditional western time display along with a display of Muslim prayer times;

FIGURE 5 is a plan view of the display face of the timepiece showing the Arabic date; '

FIGURE 6 is a plan view of the display face of the timepiece showing a longtitude display; FIGURE 7 is a plan view of the display face of the timepiece showing a time at v/hich the shadow o an object is at a specific angle (90° or 180°); and

FIGURE 8 is a flow chart of the interrupt service routine.

DETAILED DESCRIPTION

The electronic circuitry of FIG. 3 includes a quartz crystal 63 oscillating at a fixed frequency and feeding an oscillator circuit 62. From the oscillator circuit 62 a series of pulses at a fixed frequency is fed to the frequency divider and setter circuit 61. The -frequency divider and setter circuit 61 adjusts the frequency of the pulse train through frequency division and forms two pulse trains. The first pulse train 77 is fed into the timer circuitry 60 which contains counter and decoder circuitry. The second pulse train 76 forms the master clock for the remaining circuitry of FIG. 3 and is fed to the control and timing circuit 66.

There are two outputs from the timer circuit- 60. The first output 73 is the counter and decoder output representing various binary digits of traditional western time. This is fed to the main bus 53, which contains data, address and control lines, and to the input/output (I/O) multiplexer 46'. The I/O multiplexer 46 determines^' where the binary data is to be sent. In this case, the output from the I/O multiplexer 46 is passed along the bi-directional I/O bus 75 to the LCD Multiplexer 38 which addresses various LCD panel 40 segments. The LCD multiplexer 38 in turn feeds the LCD driver circuit 39 which drives the addressed segments of the LCD panel 40. The LCD panel 40 lights the various elements of the display face 1 of FIG. 1.

The particular elements of the LCD panel 1 of FIG. 1 which would be directly affected by this first output 73 from the timer- circuit 60 would be the day indicators 8, 9, 10, 11, 12, 13 and 14; the hour 24 and 25, minute 22 and 23, and second 20 and 21 indicators.

The second output 74 from the timer circuit 60 consists of periodic interrupts 65 fed to the control and timing circuit 66 approximately every 0.01 seconds and having the basic purpose of causing all circuits - to update displays and sounding the buzzer or loud speaker 45.

When power is initially supplied to the timepiece, a trigger pulse 64 resets the control and timing circuit 66 and starts the execution of the main program residing in read only memory (ROM) 55 at 56. The control and timing circuit 66 provides all the signals for program execution and data transactions among the various blocks of FIG. 3, e.g., reading and writing from read/write memory (RAM) 48, updating the LCD display 40, or sounding the buzzer or loud speaker 45.

The control an'd timing circuit 66 feeds into the conditional branch logic 67 which in turn is tied into the instruction register and decoder 68. The instruction register and decoder 68 is bi-directionally connected to the main bus 53 and provides input to the arithmetic logic unit (ALU) 69. The ALU 69 also receives input from the accumulator (ACC) 71 and temporary register 72 both of which are connected to the main bus 53.

The flag circuitry 70 is used for arithmetic and logic operations and is connected to the main bus 53, ALU.69 and conditional branch logic 67.

The ROM 55 is driven by the program counter (PC) 54 which in turn is driven across the main bus 53 by the control and timing circuit 66. The ROM 55 consists of a program memory section 56 containing the main program, interrupt service routine, control program and calculator subroutine, of a constants table section 57, of an audio generator section 58, and of a character generator section 59.

The RAM 48 is accessed via a RAM data multiplexer 80, connected by a data bus 52 to the main bus 53, and via a RAM address register and decoder 47. The RAM 48 is made up of a data storage section 49 for program variables, a memory stack section 50 for program nesting, and a registers section 51 for data manipulation. The RAM 48 also contains a copy of what the display panel 1 of FIG. 1 should look like. It also contains in its data storage section -49 the parameters entered into the input buffer 37 at points

31, 32, 33, 34, and 35 through the external switches shown in FIG. 2 as switches SI 31, S2 32, S3 33, S4 34 and S5-35. -The initial parameters- such as time, date, longtitude and latitude are manually entered into the input^* buffer 37 of FIG. 3 from the sv/itch inputs 31,

32, 33, 34 and 35. Following initializatior of the timepiece.the main program, through the control and timing circuit 66, will read the input buffer 37. If any of the switch settings at 31, 32, 33, 34 or 35 are different than those stored in the RAM data storage section 49, the main program will branch into a. particular branch for servicing that switch.

The main program is interrupt driven and upon receiving an interrupt will call in the interrupt service routine. The interrupt 65 comes from the timer circuit 60 and is passed to the main program via the control and timing circuit 66.

The interrupt service routine, through the control and timing circuit 66, will read the input buffer 37. If there has been no change in switch settings, the program will check to see if the time of day is midnight. If so, it will call the calculator program to determine the next day's prayer times ^'and will update the obligatory prayer periods shown on FIG. 1 as 2, 3, 4, 5, 6 and 7.

The inerrupt service routine is called by a signal 65 co ing from the timer circuit 60 every 0.01 seconds. A counter in the RAM data storage section 49 is incremented (or decremented) upon each call. Every 100 calls (equivalent to a one second period) the interrupt service routine updates the seconds. The minutes are updated every 60 seconds; the hours updated every 60 minutes; and so on for days, day of the week, year, etc., as shown in the flow chart in FIG. 8.

OMPI The interrupt service routine can easily be modified so that segements of the LCD panel 40 can be pulsed at particular times, especially at prayer times.

The calculator program residing in the ROM program memory section 56 calculates prayer times, direction to Kabba and also the Arabic equivalent to the present western date. -Since prayer times at a particular geographic location are dependent on the position of the sun, the calculations are based on spherical geometry. This is also the basis for^' calculating the direction to Kabba (Mecca) from a particular location.

The Arabic year consists of 12 months. The first month is 30 days and the second is 29 days, alternating between 30 days and 29 days through the remainder of the year. Once the initial Arabic date and its corresponding western date are known and inputted into the input buffer 37 by means of the switches 31 through 35, then it is a simple task to calculate one date from the other. _ -

Since any day is 24 hours long, an event, e.g., sunrise at 6:00 A.M., can be expressed in mathematical' terms. For example, 6:00 A.M. on March 10, 1983 can be expressed as 69 + 6/24 days. Where 69 stands for the 69th day in the year. Since sunrise varies with longtitude, an even more precise expression ^"would be 69 + ( 6 + λ )/24 days, where is an adjustment factor for longtitude. Knowing the time of phenomenon, e.g., sunrise, along with its relationship with the motion of the sun, one can obtain an accurate value for the sun's mean anomoly and the sun's true longtitude.

The sun's night ascension and sun's declination can be obtained from the spherical geometry of the earth and the sun. The sun's local hour angle can be obtained by knowing the sun's zenith distance at the phenomenon (e.g., the sun's zenith distance at sunrise and sunset is generally given by most nautical almanacs as 90° 50') and the latitude of the observer. Local mean time of phenomenon can then be obtained and hence, a universal time can be obtained.

The time of phenomenon at the observer can be calculated from the universal time and the known difference in time between the observer and Greenwich Mean Time. Since the time difference between Greenwich Mean Time, longtitude, latitude, date and time are initially inputted through the input buffer 37, and since the calculator program contains the relationships between the motion of the sun and the time of phenomenon, the times of sunrise, sunset, morning twilight and evening twilight can be found. Noon time is found by using the standard "Equation of Time" found in most astronomy text books.

Fo Muslims, sunrise, sunset and noon times are calculated as above. Twilights, however, are slightly different. Calculations made in several Muslim countries regarding prayer times were used to obtain a common sun's zenith distance for Muslim twilights and it was found through extensive com^*, -ter simulation that the sun's zenith distance for such times varies in most places from 106° to 110°.

Also, the beginning of ASR (midafternoon) time is defined as the time at which the shadow of an object perpendicular to the earth's surface is larger than the shadow of the same object at noon time by N times the length of the object. Two main Islamic schools differ in the value of N; some set N=l, and some set N=2. For any value of N, spherical geometry can define the sun's zenith distance at such N value.

Using the above methods the calculator program can obtain the time of any prayer period for the next twenty years with an accuracy of ± 2 minutes. The twilight times may be set for one or more countries according to the sun's zenith distance used in their current prayer calendars. Since the times of prayers used all over the world are in hours and minutes, then these calculations can be considered exact and valid with a high degree of accuracy for the following two decades.

Using spherical geometry the direction and distance to Kabba can be calculated if the longtitude and latitude of the observer and of Mecca are known. In this embodiment the longtitude and latitude of Mecca are set in the calculator subroutine and the longtitude and latitude of the observer are entered into the input buffer 37 by means of the switches 31 through 35. In other embodiments where the direction and distance between two geographic points may be desired, both sets of longtitude and latitude would be entered into the input buffer 37 by means of switches 31 through 35.

The control program will call in the calculator program when time, date and/or geographic location parameters in the input buffer 37 are changed. It will also do so at midnight of each day.

The- conditional branch logic unit 67, instruction register and decoder 68, ALU 69, ACC 71, temporary register 72 and flags circuitry 70 are used primarily by the calculator program to solve equations.

The ROM constants table 57 is used to provide values for constants in the calculator program equations such as π^* .

The timepiece has the ability to sound the Azhan through the loudspeaker 45 on FIG. 3 and at 16 on FIG. 1. Since the Azhan is.-a chant, the digital representation for that chant is held in the ROM audio generator 58 and is called by the control program when the alarm switch S3 33 on FIG. 2 is set for it through the input buffer 37 of FIG. 3.

A conventional alarm buzzer 45 is also provided as can be seen in FIG. 3 and at 15 of FIG. 1. ^" It too is called by the control program when the alarm switch S3 33 of FIG. 2 is properly set for it through the input buffer 37 ^'of FIG. 3.

The ROM character generator 59 contains binary time representations which may be called by the control program, stored in the RAM 48 and/or passed to the LCD panel 40. Also shown in FIG. 3 is the electronic circuit for lighting the timepiece's dial light 41 by means of switch 6 36. This switch is normally in the open position. The power source 42 and circuit ground 43 is also shown in FIG. 3.

FIG. 4 shows a typical time -display in the western « tradition where hours 24 and 25, minutes 22 and 23, and seconds 20 and 21 are displayed. A.M. or P.M. is indicated by a single letter at 18. Day of the week is indicated with an underline under the appropriate day as indicated at 11. Prayer times would be shown at 2, 3, 4, 5, 6 and 7.

FIG. 5 shows a display representing the Arabic date. To prevent confusion a crescent 27 is displayed at the same time. Day is indicated at 24 and 25, month at 22, and year at 20 and 21.

FIG. 6 shows a typical degrees display. In this example longtitude is displayed. Degrees are displayed at 24, 25 and 26. Minutes of degrees are displayed at 22 and 23. If the degree display is for longtitude or latitude, it is so indicated at 20 and 21 by a "LO" for longtitude and a "LA" for latitude. To prevent confusion DEG 9 is displayed when degrees are being displayed. A plus or minus sign 28 is also presented. For longtitudes the Greenwich meridian is considered to be 0°. Longtitudes west of this "would be designated with a "+" 28 and those east "-" 28. For latitudes the Equator is considered 0°. Latitudes north are "+" 28 and those south are "-" 28. FIG. 6 could also be a Kibla degree display. Kibla means the direction to Kabba in the City of Mecca, Saudi Arabia. When a Kibla degree display is being shown, 20 and 21 are blanck. The Kibla display shows the angle between Mecca and the north in degrees and minutes. A positive sign 28 indicates anti-clockwise from the north and a negative sign 28 means clo.ckwise.

FIG. 7 shows a Kibla time display. If the special symbol 30 is not displayed, then this is a display showing the time at which the sun's shadow will coincide with the Kibla (Mecca direction). If the special symbol 30 is displayed, the display shows the time at which the Kibla is 90° clockwise from the shadow. A 20 or P 20 will indicate A.M. or P.M. respectively.

FIG. 1 shows the display face 1 of a timepiece 81 shown in FIG. 2 according to the invention with all elements shown and identified. The display face 1 is electronically driven by the -^'LCD panel circuit 40 and loud speaker and buzzer circuits 45 of FIG. 3.

This invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiment disclosed is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims.

OMPI

Claims

We claim:

1. An automated muslim timepiece comprising: a timing source; an optical display; a prayer computer for calculating muslim prayer times; a time computer coupling said timing source to said optical time display and to said prayer computer; and means for coupling said prayer computer to said optical display.

2. A device according to claim 1 wherein: the time computer comprises a frequency divider and setter means connected to a timer means connected by means of display decoder and driver circuits to said -optical display and by means of a control and timing circuit to said prayer compute:

3. A device according to claim 2 wherein: the timing source is a crystal oscillator.

4. A device according to claim 3 wherein: the prayer computer comprises a means for performing arithmetic^' and logic functions, means for storing and executing programs, and means for addressing elements in said optical display.

rOREXi

O PI

5. A device according to ^*_.laim 4 further comprising: a means for entering control signals to said time computer.

6. A device according to claim 5 further comprising: a means for entering control signals to said prayer computer.

7. A device according to^' claim 6 further comprising: a means for calculating muslim prayer times.

8. A device according to claim 7 further comprising: a means for- calculating the direction to the city of Mecca, Saudi Arabia, from any given longtitude and latitude.

9. A device according to claim 8 further comprising: a means for calculating an Arabic date from western time parameters.

10*. A device according to claim 9 further comprising: a means for calculating the distance between any two^* points in the world through the input of the longtitude and latitude of these two geographic points into the timepiece.

11. A device according to claim 10 further comprising: a means of measuring the distance between Kibla and any other place in the world.

12. A device according to claim 11 further comprising: a means of calculating the direction of shortest distance between two geographic points.

13. A device according to claim 12 wherein: the optical display is a liquid crystal display.

14. A device according to claim 13 wherein: the liquid crystal display contains elements for displaying a plurality of muslim prayer times.

15. A device according to claim 14 wherein: the liquid crystal display contains elements for displaying the Arabic date.

16. A device according to claim 15 wherein: the liquid crystal display contains elements for displaying longti.tude and latitude.

17. A device according to claim 16 wherein: the liquid crystal display contains elements for displaying the Kibla direction.

18 ^'A device according to claim 17 wherein: the liquid crystal display contains elements .for displaying the Kibla time.

19. A device according to claim 18 wherein: the liquid crystal display contains elements for displaying time in a western format.

OMPI ?.0. A device according to claim 19 further comprising: a means for pulsating the liquid crystal display before or after the beginning of each muslim prayer period.

21. A device according to claim 20 further comprising: a means for pulsating individual muslim prayer time display elements as a particular prayer time occurs.

22. A device according to claim 21 further comprising: a means for sounding an alarm before or after the beginning of each m.uslim prayer time.

23. A device according to claim 22 further comprising: a means for sounding the Azhan in part or in whole before or after the beginning of each prayer time.

24. A device according to claim 23 wherein: the liquid crystal display contains elements for displaying time in a non-western format.

25. A device in accordance with claim 1 wherein: the optical display is an analog display. - .

OMPI.