JP4039098B2 - Direction indicator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an azimuth indicating device that indicates an azimuth based on time and a sun position.
[0002]
[Prior art]
Conventionally, many portable electronic devices having an orientation instruction function have been developed. For example, a wristwatch for outdoor sports is equipped with an orientation sensor and displays the orientation graphically. An azimuth sensor is a sensor that determines the azimuth by detecting the earth's magnetic field, and is composed of two orthogonal coils and a magnetoresistive element (MR element) whose resistance value changes according to the magnitude of magnetism. Things are known.
[0003]
[Problems to be solved by the invention]
In an electronic device using the above direction sensor, it is necessary to adopt an analog display function in order to accurately indicate the determined direction. In addition, the direction sensor to be used needs to have a size and a thickness that are not affected by a radio wave or a magnetic field generated by the electronic device itself and that do not hinder the portable device. From the above viewpoint, an electronic device using an orientation sensor tends to be relatively expensive. In addition, accurate orientation display is difficult for a wristwatch or the like having a simple digital display screen that displays only the date and time.
[0004]
An object of the present invention is to determine an azimuth by a simpler method without using an azimuth sensor in an azimuth indicating device, and to display the indication.
[0005]
[Means for Solving the Problems]
  The invention according to claim 1 is provided with a display screen, and an azimuth indicating device in which an azimuth mark and a plurality of solar direction indicator marks arranged on a closed curve are marked on the surface.In placeThere is a timekeeping hand that measures timeA switching input means for switching between a stage and a case where the orbit of the sun passes the south side and a case where the sun trajectory passes the north side;Time measured by the time measuring meansAnd switching instruction by the switching input meansBased on this, the deciding factor that determines the direction of the sun relative to the direction indicated by the direction markStepped,thisBased on the direction of the sun determined by the determining means, a display control unit that displays on the display screen a suggestion mark that suggests at least one of the plurality of solar direction index marks.SteppedIt is characterized by providing.
[0006]
  According to the first aspect of the present invention, the orientation mark and the solar direction indicator mark are marked on the surface. The suggestion mark indicates the position of the device by suggesting at least one of the solar direction indicator marks. Therefore, if the calculated sun direction is indicated by the suggestion mark, the user can recognize the direction by directing the position of the suggested sun direction index mark toward the actual sun. That is, as long as the suggestion mark can be displayed, the direction can be indicated without requiring a graphical display. In addition, by a simple method of calculating the direction of the sun based on the time, the general direction can be indicated without using a special sensor.Moreover, it can be indicated whether the solar orbit passes the south side or the north side.
[0007]
  The invention according to claim 2 is an azimuth indicating device provided with a display screen, wherein the azimuth mark and a plurality of solar direction indicator marks arranged on a closed curve are marked on the surface, and a time measuring means for measuring time, latitude And a storage means for storing the date, a determination means for determining whether the solar orbit passes through the south side or the north side based on the latitude and date stored by the storage means, and a time measured by the time measuring means And a determination means for determining the direction of the sun with respect to the azimuth indicated by the azimuth mark based on the determination result of the determination means, and the plurality of solar direction indicator marks based on the direction of the sun determined by the determination means. Display control means for displaying a suggestion mark suggesting at least one of the sun direction indicator marks on the display screen.
[0008]
  According to the second aspect of the present invention, the orientation mark and the solar direction indicator mark are marked on the surface. The suggestion mark indicates the position of the device by suggesting at least one of the solar direction indicator marks. Therefore, if the calculated sun direction is indicated by the suggestion mark, the user can recognize the direction by directing the position of the suggested sun direction index mark toward the actual sun. That is, as long as the suggestion mark can be displayed, the direction can be indicated without requiring a graphical display. In addition, by a simple method of calculating the direction of the sun based on the time, the general direction can be indicated without using a special sensor.Moreover, it can be indicated whether the solar orbit passes the south side or the north side.
[0009]
  And claims3As in the invention described in claim2In the azimuth indicating device according to claim 1, the determination means further determines whether or not the sun passes near the zenith.AndWhen the determination means determines that the sun passes near the zenith, a warning hand warns that correct orientation measurement cannot be performed.StepFurther, it may be further provided.
[0010]
  This claim3According to the invention described in (1), when the sun passes near the zenith, a warning is given that correct orientation measurement cannot be performed. Therefore, erroneous measurement by the user can be prevented.
[0011]
  By the way, even in an area that adopts the same standard time, in an area that is east and west away from the position of the meridian of the standard time, an error is generated between the actual position of the sun and the time by the difference in longitude. Therefore, the claim4As in the invention described in claim 1,3In the azimuth indicating device according to any one of the above, a longitude input hand for inputting longitudeStepFurther, the determining means corrects the direction of the sun to be determined based on the difference between the longitude input by the longitude input means and the longitude of the standard time meridian.To doIt is good. Thus, by correcting the error, a more accurate azimuth can be indicated.
[0012]
  And claims5As in the invention described in claim 1,4In the azimuth indicating device according to any one of the above, the solar direction indicator mark and the suggestion mark are characters or symbols indicating an angle with respect to a position of the azimuth mark, and the determining means is based on time, The angle of the sun with respect to the orientation of the orientation mark may be calculated.
[0013]
  This claim5According to the invention described in, the direction of the sun is indicated by the angle. Therefore, the user can match the direction of the azimuth indicating device and the actual sun more accurately and easily.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
The first embodiment will be described below with reference to FIGS.
FIG. 1 is a front view of a portable timepiece 1 according to the first embodiment. Referring to FIG. 1, a portable timepiece 1 includes a liquid crystal display screen 2 that displays date and time, a bezel 3 that covers the edge of the liquid crystal display screen 2, and a switch 4a for a user to input various instructions. To 4f.
[0015]
FIG. 2 is a front view of the liquid crystal display screen 2. According to the figure, the liquid crystal display screen 2 includes a liquid crystal cell group 20 for displaying hours, minutes, and seconds, and a liquid crystal cell group 21 for displaying hours, minutes, and seconds in the lower stage. ing. The control system of the portable timepiece 1 determines whether or not each liquid crystal cell is turned on according to various processing results, and displays various information on the liquid crystal display screen 2. In the first embodiment, not only the time and date are displayed on the liquid crystal display screen 2, but also the direction is designated in response to the switch input.
[0016]
On the surface of the bezel 3, as shown in FIG. 1, mark marks (N, E, S, W) indicating four directions are imprinted clockwise at intervals of 90 degrees on a concentric circle. Furthermore, on the inner concentric circle, an angle scale is engraved at intervals of 5 degrees with the position of the azimuth “N” being 0 degrees, and numbers indicating angles (0, 10, 20, 30 ... 350) at intervals of 10 degrees. Each mark is stamped clockwise.
[0017]
The switches 4a to 4f are used when the user adjusts the time or instructs the switching of the display mode. That is, the user presses the switches 4a to 4f and inputs various instructions while watching the information displayed on the liquid crystal display screen 2. The display mode includes a clock mode that displays at least the time and date, and an orientation instruction mode that displays the orientation. That is, the control system of the portable timepiece 1 displays the time and date when the clock mode is selected by switch input, and displays the direction to indicate the direction when the direction instruction mode is selected.
[0018]
Now, one of the features of the portable timepiece 1 in the first embodiment is that the direction is accurately indicated even on the liquid crystal display screen 2 having a limited display form (that is, a digital display function) as shown in FIG. It is to be.
[0019]
FIG. 3 is a schematic diagram of a celestial sphere centered on an arbitrary ground point (measurement point) 30 in the northern hemisphere. As shown in the figure, if a solar orbit 31 is projected onto a horizontal plane including the measurement point 30, the sun moves on the projected orbit 32 from the east to the south through the west. In the first embodiment, the angle θ formed by the north direction 33 centering on the measurement point 30 and the sun direction 34 seen at that time is calculated and displayed on the liquid crystal display screen 2. More precisely, the angle of the sun (hereinafter referred to as the solar direction angle (Dir)) with the north direction 33 as the reference 0 ° is calculated.
[0020]
FIG. 4 is a diagram showing an example in which the sun direction angle is displayed on the liquid crystal display screen 2. The user rotates the portable timepiece 1 based on the angle (coordinate system) engraved on the bezel 3 so that the sun direction angle displayed on the liquid crystal display screen 2 matches the direction in which the actual sun can be seen. Let On the bezel 3, north (N) and angle 0 are stamped at the same position. Therefore, if the orientation of the portable watch 1 is adjusted to the sun direction based on the angle (coordinate system) stamped on the bezel 3, the bearing (N, E, S, W) stamped on the bezel 3 and the orientation on the earth Will match.
[0021]
In the first embodiment, the solar direction angle is calculated by a simple method based on the current time.
[0022]
However, the direction in which the sun can be seen varies depending on whether the point is the southern hemisphere or the northern hemisphere, even if the region has the same time (or the region with the same longitude). FIG. 5 schematically shows a cross section including the center 41 of the earth 40. For example, the solar orbit is visible on the south side at the point a in the northern hemisphere, and the solar orbit is located on the north side at the point b in the southern hemisphere. appear.
[0023]
Therefore, the portable timepiece 1 according to the first embodiment switches between two types of solar direction angles when the sun passes through the north side and when the sun passes through the south side in response to a switch input by the user. indicate. When the user selects the north side, as shown in FIG. 6 (a), the sun direction angle when the sun looks south is displayed, and when the south side is selected, FIG. 6 (b) shows. As shown, the sun direction angle when the sun looks north is displayed.
[0024]
The internal configuration of the portable timepiece 1 according to the first embodiment will be described below. FIG. 7 is a diagram illustrating an example of the internal configuration of the portable timepiece 1. According to the figure, the portable timepiece 1 includes a CPU 10, a ROM 11, a RAM 12, a display drive circuit 13, a display unit 14, an oscillation frequency dividing circuit 15, a time / date counting circuit 16, a switch unit 17, Is mainly provided.
[0025]
The CPU 10 reads a predetermined program from the ROM 11 based on an instruction input via the switch unit 17 and temporarily stores it in the RAM 12, executes various processes based on the program, and centrally controls each unit of the portable timepiece 1. . That is, the CPU 10 executes various processes based on the read predetermined program, stores the processing results in the work memory in the RAM 12, and causes the display unit 14 to display the process results.
[0026]
Further, the CPU 10 stores in the ROM 11 a process for calculating and displaying the sun direction angle (solar position display process) and a process for setting whether the solar orbit is north side or south side in response to the switch input (switch process). Execute according to the stored program.
[0027]
The ROM 11 is a read-only semiconductor memory and stores a basic program executed by the portable timepiece 1. Specifically, a date / time display program for displaying the date / time, a mode switching program for switching various modes in response to switch inputs, and character / numeric data for displaying various characters and numbers on the liquid crystal display screen 2 Remember. The ROM 11 stores a sun position display program 110 for the CPU 10 to execute the sun position display process and a north-south switching program 111 for executing the switch process.
[0028]
The ROM 11 may be an erasable / writable storage medium such as a flash memory, and may be configured to store a processing result by the CPU 10. Alternatively, an external communication unit may be further provided so that an externally input program or data can be taken in and stored, and the program can be realized by the CPU 10. In other words, the solar position display program 110 and the north-south switching program 111 may be externally captured and stored, and processed by the CPU 10.
[0029]
The RAM 12 is a storage medium for temporarily storing data. The RAM 12 is a work storage area for temporarily storing a program expansion area for expanding a program executed by the CPU 10, data input from the switch unit 17, various processing results of the CPU 10, and the like. Area, etc. The RAM 12 has a solar orbit storage area 120 for storing the direction of the solar orbit (north or south) set by the switch process. However, when a flash memory is used as the ROM 11, the direction of the solar orbit may be stored in the flash memory.
[0030]
The display unit 14 includes the liquid crystal display screen 2 shown in FIG. 1 and is a functional unit that displays the date and time, the sun direction angle, and the like. The display drive circuit 13 is a circuit for controlling whether or not each liquid crystal cell of the liquid crystal display screen 2 is lit in response to a display signal input from the CPU 10.
[0031]
The oscillation frequency dividing circuit 15 has an oscillator and distributes a basic pulse and its frequency-divided signal to each part. The time / date counting circuit 16 increments and decrements a register that stores seconds, minutes, hours, days, days of the week, months, years, and the like, and the corresponding register in response to an electric signal input from the oscillation frequency dividing circuit 15. A circuit, and a circuit for reading and updating the register information in response to an instruction signal input from the CPU 10.
[0032]
The switch unit 17 is a functional unit corresponding to the switches 4a to 4f of the portable timepiece 1 shown in FIG. 1, and when the switch 4a to 4f is pressed by the user, signals based on the switches 4a to 4f are sent to the CPU 10. Output.
[0033]
Then, the solar position display process which CPU10 performs is demonstrated. FIG. 8 is a flowchart illustrating the sun position display process.
When an instruction to switch to the direction instruction mode is input from the switch unit 17, the CPU 10 acquires the current time from the time / date counting circuit 16 (step S1). Then, the sun direction angle is calculated based on the current time input from the time / date counting circuit 16. Although the sun's direction is different depending on whether the solar orbit is on the south side or the north side when viewed from the measurement point, the solar direction angle (Dir) is calculated assuming that the orbit is on the south side. Step S2).
[0034]
In the first embodiment, the solar direction angle (Dir) is calculated by the following calculation formula by a simple method.
Dir = current time × 15 (1)
This is based on the assumption that the sun is on the east side (90 ° position on the bezel 3) at 6:00 am with respect to the measurement point and moves to the west side (180 ° position on the bezel 3) over approximately 12 hours. This is the calculation method. In other words, it is a method of deriving the solar direction angle from the current time using the fact that the sun moves 15 ° per hour. For example, if the current time is 7:40 am, convert "minutes" to "hour" units,
Dir = (7+ (40/60)) × 15 (2)
Calculate as Or if the current time is 15:16,
Dir = (15+ (16/60)) × 15 (3)
Calculate as
[0035]
When the sun direction angle (Dir) is calculated, the CPU 10 reads the direction stored in the solar orbit storage area 120 of the RAM 12 and determines whether the orbit is on the south side (step S3). When the orbit passes the south side, the sun direction angle (Dir) calculated in step S2 is displayed as it is on the liquid crystal display screen 2 (step S7).
[0036]
On the other hand, if it is determined in step S3 that the sun passes the north side, the solar direction angle value (Dir) calculated assuming the south side is converted into a sun direction angle when the sun passes the north side. To do.
[0037]
Hereinafter, the conversion method will be described. In the northern hemisphere, the sun moves from the east through the south to the west, and in the southern hemisphere, it moves from the east to the north through the west. In terms of the angle on the bezel 3, in the northern hemisphere, it moves clockwise from 90 ° to 180 ° to 270 °. On the other hand, in the southern hemisphere, it moves counterclockwise from 90 ° through 0 ° to 270 °. That is, on the south side and the north side, the sun moves symmetrically about the line segment connecting east and west (EW).
[0038]
Therefore, in the first embodiment, when the sun passes through the north side, the angle is displayed counterclockwise (counterclockwise) with respect to the position of south “S”. Specifically, the angle is converted to an angle based on the position of 180 ° by the following equation (step S4).
Dir = 180−Dir (4)
Here, the value of (Dir) on the right side is a value calculated by Equation (1) assuming the solar orbit on the south side.
[0039]
Note that the solar direction angle (Dir) converted by the equation (4) may be negative. Therefore, the CPU 10 determines whether or not Dir is negative (step S5). When Dir is a value equal to or greater than 0 (Dir ≧ 0), the Dir value is displayed on the liquid crystal display screen 2 as it is (step S7). On the other hand, if Dir is negative (Dir <0), it is converted to a positive number by the following equation (step S6).
Dir = Dir + 360 (5)
Here, the value of (Dir) on the right side is the solar direction angle calculated by Equation (4) in Step S4. When the CPU 10 converts (Dir) to a positive number according to the equation (5), the CPU 10 displays the value on the liquid crystal display screen 2 (step S7), and ends this processing.
[0040]
In this way, by displaying the solar direction angle corresponding to the orbit of the sun, it is possible to correctly indicate the azimuth even if the user exists in either the northern hemisphere or the southern hemisphere.
[0041]
Next, switch processing executed by the CPU 10 will be described. FIG. 9 is a flowchart for explaining the switch process.
When any of the switches 4a to 4f is pressed, the CPU 10 interrupts the process being executed and starts the switch process. First, the CPU 10 determines whether or not the input switch is a north-south switching switch (step S10). At this time, when a switch other than the switch for north-south switching is input, the process proceeds to another switch process. On the other hand, if the switch input is an instruction to switch between north and south, it is determined whether or not the instruction indicates the north side (step S11).
[0042]
If the determination on the north side is made in step S11, the fact that it is on the north side is stored in the solar orbit storage area 120 of the RAM 12 (step S12). On the other hand, when the determination on the south side is made, the fact that it is on the south side is stored in the solar orbit storage area 120 of the RAM 12 (step S13). Then, this process ends.
[0043]
According to such processing, the user can easily set whether the solar orbit is south or north by switch input.
[0044]
As described above, according to the first embodiment, even in a portable timepiece having a limited display screen, that is, a display screen that enables only digital display, the direction of the sun can be displayed more accurately and the direction can be set. It becomes possible to instruct. In addition, it is possible to accurately indicate the direction regardless of whether the user exists on the north or south on the earth.
[0045]
[Second Embodiment]
Next, a second embodiment will be described with reference to FIGS.
The second embodiment is an embodiment in which the orientation of the solar orbit is automatically calculated using the portable timepiece 1 described in the first embodiment. Therefore, the description of the points common to the first embodiment is omitted, the same functions and configurations are denoted by the same reference numerals, and differences will be mainly described.
[0046]
FIG. 10A is a schematic diagram showing the positional relationship between the sun and the earth in spring equinox and autumn equinox. According to the figure, the sun in the middle passes through the zenith at point A on the equator. On the other hand, at the point B at north latitude ω, the sun at mid-time (south / central time) tilts southward from the zenith by the amount of latitude ω.
[0047]
FIG. 10B is a schematic diagram showing the positional relationship between the sun and the earth during the winter solstice. According to the figure, the sun at midline passes through the zenith at point C on the southern return line (south latitude φ = 23.4 °). At this time, the midday sun at point A on the equator tilts south from the zenith by the angle φ. On the other hand, at the point B at the north latitude ω, the sun at the midline tilts further south from the zenith by the latitude ω than the angle φ.
[0048]
FIG. 11 is a table showing the solar altitude at the midpoint at each measurement point. In this table, the zenith is 0 °, the north direction is +, and the south direction is-. According to the table, in the area of latitude 0.0, that is, the area on the equator, the solar altitude is 0.0 °, that is, the sun passes near the zenith at the time of spring equinox and autumn equinox, and in the summer solstice in a direction inclined 23.4 ° north from the zenith. The sun passes, and in the winter solstice the sun passes 23.4 ° from the zenith to the south.
[0049]
In areas other than the equator, the sun passes through the altitude obtained by subtracting the latitude value from the solar altitude at the equator.
Solar altitude = Solar altitude above the equator-Latitude (6)
For example, in an area with a latitude of 15.0, the solar altitude is -15.0 ° during spring and autumn, 8.4 ° during the summer solstice, and 38.4 ° during the winter solstice.
[0050]
Using the above principle, in the second embodiment, the solar altitude is calculated, and it is automatically determined whether the solar orbit is on the south side or the north side.
[0051]
The portable timepiece 1 according to the second embodiment stores a trajectory determination program 112 for executing the trajectory determination process described below in the ROM 11 (FIG. 12A), and the trajectory determination related to the CPU 10 is performed. A trajectory determination process described later is executed according to the program 112. The RAM 12 according to the second embodiment includes a latitude storage area 121 for storing latitude (FIG. 12B), and the CPU 10 responds to an input signal from the switch unit 17 and calculates a latitude value. It is determined and stored in the latitude storage area 121 in the RAM 12. When the ROM 11 is realized by a flash memory, the latitude value may be stored and held in the flash memory.
[0052]
Hereinafter, the trajectory determination process will be described with reference to the flowchart shown in FIG.
CPU10 will acquire a date from the time date counting circuit 16, if the instruction | indication which switches to the azimuth | direction instruction mode is input from the switch part 17 (step S20). Then, based on the date input from the time date counting circuit 16, the solar altitude at the mid-centre on the equator (the angle at which the vertex position is 0 °: Ang) is calculated (step S21).
[0053]
There are various methods for calculating the mid-day solar altitude on the equator. For example, it is calculated as follows. The total number of days from the day of the winter solstice, that is, the day when the sun passes on the southern return line, is n.
Ang = −23.4 + (46.8 / 183) × n (1 ≦ n ≦ 183) (7)
Ang = 23.4− (46.8 / 183) × (n−183) (184 ≦ n ≦ 365) (8)
Calculated by However, “365” may be changed to “364” in a leap year.
[0054]
When the solar altitude (Ang) on the equator is calculated, the CPU 10 reads the latitude value from the latitude storage area 121 of the RAM 12 and calculates the solar altitude (LocAng) at the midpoint at the measurement point (step S22). The mid-point solar altitude (LocAng) at the measurement point is determined based on the following equation. That is,
LocAng = Ang-Latitude (9)
The latitude is + for the northern hemisphere and-for the southern hemisphere.
[0055]
When the midpoint solar altitude (LocAng) at the measurement point is calculated, the CPU 10 determines whether (LocAng) is positive (step S23). If it is positive (LocAng> 0), the fact that it is the north side is stored in the solar orbit storage area 120 of the RAM 12 (step S24). On the other hand, if it is negative (LocAng <0), the fact that it is the south side is stored in the solar orbit storage area 120 of the RAM 12 (step S25). When the above process ends, the process proceeds to the sun position display process (see FIG. 8) (step S26), and this process ends.
[0056]
According to the above, based on the date and the latitude of the measurement point, the mid-day solar altitude at the measurement point is calculated, and the solar orbit is automatically determined to be the south side or the north side. Therefore, even when the user exists in an area between the north return line and the south return line, it is possible to accurately indicate the direction without causing the user to determine the direction of the solar orbit. .
[0057]
In the second embodiment, the mid-day solar altitude (LocAng) may be located near the zenith (LocAng = 0). In this case, it is not possible to determine whether the orbit of the sun is on the south side or the north side, and since the sun passes overhead, the user cannot rotate the portable timepiece 1 according to the direction of the sun. Therefore, when the mid-day solar altitude is located near the zenith, a warning may be given that the direction cannot be indicated.
[0058]
FIG. 14 is a flowchart for explaining the “trajectory determination process 2” including a step of executing a warning. In the figure, the processing in steps S20 to S25 is the same as the trajectory determination processing described with reference to FIG.
[0059]
When the CPU 10 finishes the process of setting whether the solar orbit is on the south side or the north side in step S24 or step S25, the CPU 10 determines whether or not the mid-point solar altitude at the measurement point is near the zenith (step T1). Specifically, for example, it is determined whether or not the mid-day solar altitude (LocAng) satisfies the determination range (−γ ≦ LocAng ≦ γ), and if so, the sun cannot be correctly displayed as being near the zenith. (Step T2). The warning may be performed by displaying on the liquid crystal display screen 2 that the direction cannot be instructed, or may be performed by generating a beep sound with a simple speaker (not shown). On the other hand, when it determines with the sun not being near the zenith in step T1, it transfers to a solar position display process (step S26), and complete | finishes this process.
[0060]
In this way, when the sun passes near the zenith, it is possible to prevent an erroneous measurement by the user by giving a warning. Even when the warning is given as described above, only the east and west directions can be discriminated unless the sun is in the middle of the south, so only the east or west direction is displayed in this case. You may make it do.
[0061]
[Third Embodiment]
Next, a third embodiment will be described with reference to FIGS.
The third embodiment is an embodiment in the case where the calculated solar direction angle (Dir) value is corrected according to the area using the portable timepiece 1 described in the first embodiment. Therefore, the description of the points common to the first embodiment is omitted, the same functions and configurations are denoted by the same reference numerals, and differences will be mainly described.
[0062]
As described in the first embodiment, when the solar direction angle is calculated using the current time, since the solar direction angle is a value on the standard time meridian, the difference in longitude in an area other than the standard time meridian Even at the same time, the direction of the sun is off. For example, in Japan, the standard time meridian is the position of Akashi City (135 degrees longitude), and the direction of the sun is slightly different from Tokyo at 140 degrees longitude.
[0063]
Therefore, in the third embodiment, the angle difference of the solar direction angle is corrected based on the longitude at the measurement point and the longitude of the standard time meridian. The angle difference can be calculated by the following equation.
Angle difference = Longitude of measurement point-Longitude of meridian of standard time (10)
Note that the longitude of the standard time meridian may be determined based on the time difference from Greenwich mean time (GMT). For example, since Japan is GMT + 9.0, the longitude of the standard time meridian can be calculated by 9.0 × 15. That is, equation (10) is
Angle difference = longitude of measurement point−GMT time difference × 15 (11)
Any expression can be used.
[0064]
Now, if the angle difference calculated by Formula (10) or Formula (11) is added to the sun direction angle calculated based on the standard time (current time), a more correct value (Dir) can be determined. That is,
Dir = (hour + minute / 60) x 15 + (angle difference)
= (Hour + minute / 60) x 15 + (measurement longitude-time difference x 15) (12)
Can be determined.
[0065]
In the third embodiment using the above principle, the solar direction angle calculated using the standard time is corrected. Hereinafter, the sun position display process including the correction process is referred to as a sun position display process 2.
[0066]
Note that the portable timepiece 1 according to the third embodiment stores a sun position correction program 113 for the CPU 10 to execute the sun position display process 2 in the ROM 11 (FIG. 15A). Further, the RAM 12 in the third embodiment has a longitude storage area 122 for storing longitude input from the switch unit 17 and a time difference storage area 123 for storing GMT time difference input from the switch unit 17. (FIG. 15B). That is, the CPU 10 stores the longitude in the longitude storage area 122 of the RAM 12 when the longitude is input from the switch unit 17, and stores the GMT time difference in the time difference storage area 123 when the GMT time difference is input. Remember. However, when the ROM 11 is realized by a flash memory, the longitude and GMT time difference at the measurement point may be stored and held in the flash memory.
[0067]
Next, the solar position display process 2 executed by the CPU 10 in the third embodiment will be described using the flowchart shown in FIG. In the figure, the processes of steps S1 to S2 and steps S3 to S7 are the same as the solar position display process described with reference to FIG.
[0068]
When the solar direction angle (Dir) is calculated in step S2 assuming the south orbit, the CPU 10 calculates the longitude stored in the longitude storage area 122 of the RAM 12 and the GMT time difference stored in the time difference storage area 123. And is substituted into equation (11) to calculate the angle difference (step P1). Then, the sun direction angle (Dir) is corrected by adding the angle difference calculated in Step P1 to the sun direction angle (Dir) calculated in Step S2 (Step P2). When the correction for the sun direction is completed, the process proceeds to step S3, and the same process as the solar position display process described with reference to FIG. 8 in the first embodiment is performed.
[0069]
As described above, by correcting the solar direction based on the longitude of the standard time meridian and the longitude of the measurement point, it is possible to accurately indicate the azimuth even in the longitude region away from the position of the standard time meridian.
[0070]
The implementation of the present invention is not limited to that described in the first to third embodiments, and various modifications can be made. For example, in the first to third embodiments, it has been described that an angle is displayed as an index indicating the direction of the sun, but it is not necessary to limit the angle.
[0071]
For example, as shown in FIG. 17, numbers 1 to 4 are imprinted clockwise on the bezel 3 under the four directions (N, E, S, W), and the sun is used using the numbers 1 to 4 The direction may be indicated. In this case, for example, “12” is displayed when the sun is in a 45 ° direction, and “441” is displayed when the sun is 280 °. It doesn't matter. In this way, it is possible to indicate the direction by imprinting characters or symbols other than angles on the bezel 3 and displaying the characters and symbols in combination.
[0072]
Further, in the first to third embodiments, the character mark indicating the azimuth, the angle scale, and the number mark indicating the angle are formed by engraving on the bezel, but may be formed directly on the case, glass, dial, or parting out Of course, it may be formed on a plate, and the formation method is not limited to engraving but may be other methods such as printing.
[0073]
In the first to third embodiments, the portable timepiece 1 has been described as an example of the azimuth indicating device. However, the present invention is not limited to this, and any electronic device having a timekeeping function may be used, for example, a PDA (Personal Digital Assistant) or a cellular phone may execute the various functions described in the first to third embodiments.
[0074]
【The invention's effect】
  According to the azimuth indicating device according to the first aspect, the direction of the sun is determined based on the time, and the solar position index mark marked on the case is suggested based on the determination. The user can grasp the azimuth by rotating the case so that the positional relationship of the suggested solar position index mark matches the actual sun. Therefore, as long as the suggestion mark for suggesting the solar position index mark can be displayed, the direction can be indicated on a simple display screen. Further, since the direction of the sun is calculated based on the time, the direction can be instructed without using a sensor or the like.In response to the switching instruction, the solar trajectory switches between north and south to determine the sun direction. Therefore, even when the direction of the sun is calculated based on the time, the direction can always be accurately indicated.
[0076]
  Claim2According to the azimuth indicating device described in the above, it is determined whether the solar orbit is south or north based on the latitude and date. That is, since the sun's orbit is automatically determined, it is possible to always instruct the direction accurately without relying on the user input.
[0077]
  Claim3According to the azimuth indicating device described in 1), when the sun passes near the zenith, a warning is given that the azimuth measurement cannot be performed correctly, so that erroneous measurement can be prevented.
[0078]
  Claim4According to the azimuth indicating device described in the above, the sun direction is corrected based on the difference between the input longitude and the longitude of the standard time meridian. Therefore, the direction can be indicated more accurately even in an area distant from the standard meridian position east and west.
[0079]
  Claim5According to the azimuth indicating device described in the above, the angle of the sun is suggested by the angle. Therefore, it is possible to instruct the direction in a form that makes it easier for the user to determine the direction.
[Brief description of the drawings]
FIG. 1 is a front view of a portable timepiece.
FIG. 2 is a front view of a liquid crystal display screen.
FIG. 3 is a schematic diagram of a celestial sphere centered on a measurement point.
FIG. 4 is a front view of a bezel and a liquid crystal display screen.
FIG. 5 is a diagram for explaining the difference in the appearance of the solar orbit between the northern and southern hemispheres.
FIG. 6 is a diagram showing an example in which a solar direction angle is displayed. (A) shows the case of the northern hemisphere, and (b) shows the case of the southern hemisphere.
FIG. 7 is a diagram illustrating an example of an internal configuration of a portable timepiece.
FIG. 8 is a flowchart illustrating solar position display processing.
FIG. 9 is a flowchart illustrating switch processing.
FIG. 10 (a) is a schematic diagram showing the positional relationship between the sun and the earth during the spring equinox. (B) is a schematic diagram showing the positional relationship between the sun and the earth during the winter solstice.
FIG. 11 is a solar altitude table at mid-time.
FIG. 12A is a diagram illustrating an example of contents stored in a ROM according to the second embodiment;
(B) is a figure which shows an example of the storage content of RAM in 2nd Embodiment.
FIG. 13 is a flowchart illustrating trajectory determination processing.
FIG. 14 is a flowchart for explaining trajectory determination processing 2;
FIG. 15A is a diagram illustrating an example of contents stored in a ROM according to the third embodiment;
(B) is a figure which shows an example of the storage content of RAM in 3rd Embodiment.
FIG. 16 is a flowchart illustrating solar position display processing 2;
FIG. 17 is a front view of a portable timepiece showing a modification of a mark engraved on the bezel.
[Explanation of symbols]
1 Mobile watch
2 LCD screen
3 Bezel
4a-4f switch
10 CPU
11 ROM
12 RAM
13 Display drive circuit
14 Display section
15 Oscillation frequency divider
16 Time and date counting circuit
17 Switch part

Claims (5)

An azimuth indicating device comprising a display screen, wherein a azimuth mark and a plurality of solar direction indicator marks arranged on a closed curve are marked on the surface,
A time measuring means for measuring time;
A switching input means for switching between a case where the solar orbit passes the south side and a case where the sun trajectory passes the north side;
Determining means for determining the direction of the sun relative to the azimuth indicated by the azimuth mark based on the time measured by the time measuring means and the switching instruction by the switching input means ;
Based on the direction of the sun determined by the determining means, display control means for displaying on the display screen an indication mark suggesting at least one solar direction index marks of the plurality of solar direction index marks,
An azimuth indicating device comprising: An azimuth indicating device having a display screen, wherein a azimuth mark and a plurality of solar direction indicator marks arranged on a closed curve are marked on the surface,
A time measuring means for measuring time;
Storage means for storing latitude and date;
Determining means for determining whether the solar trajectory passes through the south side or the north side based on the latitude and date stored by the storage means;
Determining means for determining the direction of the sun relative to the azimuth indicated by the azimuth mark based on the time measured by the time measuring means and the determination result of the determining means;
Based on the direction of the sun determined by the determining means, display control means for displaying on the display screen a suggestion mark that suggests at least one solar direction index mark among the plurality of solar direction index marks;
An azimuth indicating device comprising: In the direction indicating device according to claim 2,
The determination means further determines whether or not the sun passes near the zenith,
An azimuth indicating apparatus further comprising warning means for warning that the azimuth cannot be measured correctly when the determining means determines that the sun passes near the zenith. In the azimuth | direction direction apparatus in any one of Claim 1 to 3,
A longitude input means for inputting longitude;
The azimuth indicating device characterized in that the determining means corrects the direction of the sun to be determined based on a difference between the longitude input by the longitude input means and the longitude of the standard time meridian. In the direction indicating device according to any one of claims 1 to 4,
The solar direction indicator mark and the suggestion mark are characters or symbols indicating an angle with respect to the position of the orientation mark,
The deciding means calculates an angle of the sun with respect to the azimuth of the azimuth mark based on time.

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