Patent Application
20090161120
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2007-331355, filed on Dec. 25, 2007, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a hand position detecting device and method which detects the rotational positions of seconds, center and hour hands.
2. Description of the Related Art
In the past, a hand position detecting device which detects the rotational positions of hands of a timepiece is known, as disclosed by Japanese Published Unexamined Application 2000-162336. This device comprises a first drive system in which a first drive motor transmits its rotation to a seconds wheel which in turn causes a seconds hand to sweep around a dial, a second drive system in which a second drive motor transmits its rotations to the center and hour wheels to cause the seconds and hour hands, respectively, to sweep around the dial. This device also includes a photosensor which, when the seconds, center and hour wheels of the first and second drive systems are rotated after pointing to the same direction on the same axis, optically detects, with the aid of a light emission element and a photo detection element included in the photosensor, a first, a second and a third light-passing apertures provided in the seconds, center and hour wheels, respectively, such that the respective rotational positions of the seconds, center and hour wheels and hence the seconds, center and hour hands are determined based on detected signals from the photosensor.
However, in this apparatus, the moving positions of the seconds, center and hour hands are only determined. Thus, when it is determined that these hands move around the dial correctly, they are required to continue to do so normally. However, when the positions of the seconds, minute and hour hands cannot be detected, such detection tends to be repeatedly many times, thereby consuming a significant amount of battery power.
It is therefore an object of the present invention to provide a hand position detecting apparatus and method for stopping the detection of the hand positions when the seconds, center and hour hand positions cannot be detected, thereby preventing useless power consumption.
In one aspect, the present invention provides a hand position detecting device having a plurality of hand wheels each with a corresponding hand, each hand wheel having at least one light-passing aperture therein, the device comprising:
an optical detection unit configured to detect passage of light through a plurality of light-passing apertures in the plurality of hand wheels, each aperture included in the at least one aperture in a respective one of the hand wheels;
a position detecting unit configured to optically detect the respective positions of the hand wheels on the basis of a transmitted state of light detected by the optical detection unit; and an optical detection controlling unit configured to count the number of times the position detecting unit has successively failed to detect the positions of the hand wheels, determine if the counted number of times is equal to, or has exceeded, a predetermined number of times, and stop, if so, the position detecting unit from detecting the hand wheel positions for a time period ranging from when the position detection controlling unit has determined that the position detecting unit has successively failed to detect the positions of the hands the predetermined number of times to a predetermined time.
In another aspect, the present invention provides a hand position detecting device having a plurality of hand wheels each with a corresponding hand, each hand wheel having at least one light-passing aperture therein, the device comprising: an optical detection unit configured to detect passage of light through a plurality of light-passing apertures in the plurality of hand wheels, each aperture included in the at least one aperture in a respective one of the hand wheels; a position detecting unit configured to optically detect the respective positions of the hand wheels on the basis of a transmitted state of light detected by the optical detection unit; a position detection error reporting unit responsive to the position detecting unit failing to detect the positions of the hand wheels, configured to report to a user a hand position detection error indicating that the position detecting unit has failed to detect the positions of the hand wheels; and an optical detection controlling unit configured to determine if the position detecting unit has failed to detect the positions of the hand wheels successively a predetermined number of times, and configured to stop the position detecting unit from detecting the respective hand wheel positions for a time period ranging from when the optical detection controlling unit has determined that the position detecting unit has failed to detect the positions of the hands successively the predetermined number of times to a predetermined time.
In a further aspect, the present invention provides a hand position detecting device having a plurality of hand wheels each with a corresponding hand, each hand wheel having at least one light-passing aperture therein, the device comprising: an optical detection unit configured to detect passage of light through a plurality of light-passing apertures in the plurality of hand wheels, each aperture included in the at least one aperture in a respective one of the hand wheels; a position detecting unit configured to optically detect the respective positions of the hand wheels on the basis of a transmitted state of light detected by the optical detection unit; an optical detection controlling unit configured to determine if a position detection error indicating that the position detecting unit has failed to detect the respective positions of the hand wheels is produced successively a predetermined number of times, and configured to stop, if so, the position detecting unit from detecting the respective positions of the hand wheels for a time period ranging from when the optical detection controlling unit has determined that the position detection error has been produced successively the predetermined number of times to a predetermined time; and an operation unit configured to operably select one of a normal hand rotating mode in which the hands are rotated normally and an error display mode in which the contents of the hand position detection error are displayed.
In accordance with the invention, when the position detecting unit has failed to detect the positions of the hand wheels successively the predetermined number of times, the optical detection controlling unit stops the position detecting unit from detecting the position detection until the predetermined time. That is, the detection of the hand wheel positions is not required to be repeated unnecessarily many times and useless consumption of the battery power is prevented.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the present invention and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the present invention in which:
Referring to
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
The pinion 22d of the rotor 22 of the second driving system 12 rotates 180 degrees or one step per pulse. The intermediate wheel 23 rotates 30 degrees per pulse (or per step of the rotor 22c rotation), thereby making one rotation with 12 pulses (in 12 steps of the rotor 22c rotation). The third wheel 24 rotates 4 degrees per pulse (or per step of the rotor 22c rotation). The center wheel 25 rotates one degree per pulse (or per step of the rotor 22c rotation), and makes one rotation with 360 pulses (in 360 steps of the rotor 22c rotation). The minute wheel 26 rotates ⅓ degrees per pulse (per step of the rotor 22c rotation). The hour wheel 27 rotates 1/12 degrees per pulse (per step of the rotor 22c rotation) and hence makes one rotation with 4320 pulses (in 4320 steps of the rotor 22c rotation).
As shown in
As shown in
As shown in
As shown in
The second light blocking area 21e is longer by an angular extent of approximately the angle of the circular aperture 21a as viewed from the center of the seconds wheel 20 than the first light blocking area 21d. That is, the second light blocking area 21e extends through an angular extent of approximately 4 times the angle of the circular aperture 21a as viewed from the center of the seconds wheel 20, or through a net angular extent of approximately 48 degrees from the center of the circular aperture 21a (or the reference or 0-degree position) to an approximately 60 degree or 50 seconds position in the clockwise direction. As shown in
The first light blocking area 21d is diametrically opposed to part of the arcuate aperture 21c. The second light blocking area 21e is diametrically opposed to part of the arcuate aperture 21b. As described above, the third blocking area 21f is diametrically opposed to the circular aperture 21a. Thus, when the seconds wheel 20 rotates clockwise 180 degrees (or half rotation) from the state in which any one of the first-third light blocking areas 21d-21f blocks the detection position P in the detection unit 13 where the light emission element 31 faces the photo detection element 32, any of the circular and arcuate apertures 21a, 21b and 21c is arranged to align wholly or partially with the detection position P necessarily. In the description, when the rotating directions of the seconds, center and hour wheels 20, 25 and 27 are not specified, they should be rotated clockwise around their respective rotational axes, as shown by arrows in the respective FIGS. 5 and 10A-15F, and at this time the rotating direction of the intermediate wheel 23 should be counterclockwise.
While the seconds wheel 20 rotates around a center axis thereof 2 steps, 12 degrees or 2 seconds at a time until it rotates 60 steps, 360 degrees or 60 seconds in total, the detection unit 13 tries to detect light or apertures at intervals of 2 seconds, thereby producing a detected pattern shown in
When the seconds wheel 20 is between an 8 seconds or 48 degree position and a 28 seconds or 168 degree position, the detection unit 13 detects light or the arcuate aperture 21b continuously. When the seconds wheel 20 is at a 30 seconds or 180 degree position, the third light blocking area 21f blocks the detection position P, and hence the detection unit 13 cannot detect apertures. When the seconds wheel 20 is between a 32 seconds or 182 degree position and a 50 seconds or 300 degree position, the detection unit 13 detects light or the arcuate aperture 21b continuously. When the seconds wheel 20 is between at a 52 seconds or 312 degree position and a 58 seconds or 348 degree position, the light blocking area 21e blocks the detection position P, and hence four non-detection events occur successively to the detection unit 13.
As shown by a solid line in
As shown in
As shown in
The intermediate, center and hour wheels 23, 25 and 27 of the second driving system 12 rotate 30, 1 and 1/12 degrees, respectively, in one step or one half rotation of the rotor 22c. Thus, as shown in
The seconds wheel 20 of the first driving system 11 rotates 6 degrees (or a half rotation of the rotor 17c) per step. Each time the seconds wheel 20 rotates 60 steps or seconds, its aperture 21a aligns with the detection position P. Thus, as shown in
Description will be made of preconditions for detecting the driving positions of the seconds, center and hour hands 2, 3 and 4 with the detection unit 13. When the seconds, center and hour hands 2, 3 and 4 point to the same 12 o'clock direction (in
Since the light from the light emission element 31 is blocked when any of those apertures is offset or away from the detection position P, no light from the light emission element 31 is received by the photo detection element 32.
By reversing 180 degrees the rotation of the respective rotors 17c and 22c of the first and second stepping motors 17 and 22, the respective seconds, center and hour hands 2, 3 and 4 are rotated one step. To this end, pulses of opposite polarities are applied alternately to each of the stepping motors 17 and 22 at every step, thereby rotating the rotors 17c and 22c. Thus, even when pulses of the same polarity are applied successively to a respective one of the stepping motors 17 and 22, the respective rotors 17c and 22c do not rotate and remain stopped.
In the first stepping motor 17 of the first driving system 11, unless the seconds wheel 20 rotates 2 steps, its circular aperture 21a does not completely move away from the detection position P due to a relationship between the size of the aperture 21a and a moving quantity per step of the seconds wheel 20 rotation. Thus, with the seconds wheel 20, it is effective that the detection unit 13 tries to detect light at every 2 steps (or seconds) of the seconds wheel 20 rotation. With the second driving system 12, it is effective that the detection unit 13 tries to detect light at every step.
Then, referring to
The reference position in the seconds wheel 20 can be obtained by detecting the reference or 00 seconds position in the seconds wheel 20 shown in
First, when the seconds wheel 20 rotates clockwise 2 steps from the state of
Then, as shown in
As shown
Then, as shown in
Similarly, as shown in
As described above, in the state of
As will be known from the above, the detection unit 13 cannot detect light in both the states of
More particularly, each time the seconds wheel 20 rotates 2 steps or seconds, the detection unit 13 tries to detect light. When four successive non-detection events occur and the detection unit 13 detects light in next 2 steps of the seconds wheel rotation, the aperture 21a aligns with the detection position P. Thus, it will be seen that the reference or 00-second position in the seconds wheel 20 has aligned with the detection position P. If the number of non-detection events is counted from the state of
Then, referring to
Both the reference or 0-o'clock and 00-minute positions in the center and hour wheels 25 and 27 can be obtained by detecting the reference positions in them shown in
When the center wheel 25 is rotated clockwise one step or degree in
Then, when the center wheel 25 rotates clockwise one step at a time and hence 6 steps or degrees in total, the intermediate wheel 23 rotates 180 degrees clockwise, its aperture 30 rotates counterclockwise 180 degrees away from the detection position P, and thus the intermediate wheel 23 continues to cover the detection position P, as shown in
Then, when the center wheel 25 rotates clockwise one step at a time until 12 steps or degrees in total are reached, the intermediate wheel 23 rotates 360 degrees and its aperture 30 aligns with the detection position P, as shown in
When the center wheel 25 rotates 360 steps or makes one rotation clockwise from the state of
Then, when the center wheel 25 rotates further one hour (or 11 hours in all), the apertures 28 and 30 in the center and intermediate wheels 25 and 23 align with the detection position P, as shown in
When the center wheel 25 rotates further for one hour (or 12 hours in all), the apertures 28 and 30 in the center and intermediate wheels 25 and 23 align with the detection position P, as shown in
As described above, since a rotational quantity of the center wheel 25 for one step is very small or one degree, it is not enough for the rotational amount per step of the center wheel 25 to cause the aperture 28 to move completely away from the detection position P, and the reference position in the center wheel 25 can not be detected accurately. The intermediate wheel 23 rotates 30 degrees per step. Thus, even when the rotational amount per step of the center wheel 25 rotation is small, the rotational amount of the intermediate wheel 23 is large enough to cover the detection position P.
As shown in
Each time the center wheel makes one rotation in 360 steps, thereby returning to the detection point P, the aperture 28 and 30 in the in the center and intermediate wheels 25 and 23 and a relevant one of the apertures 29 in the hour wheel 27 (aside from the blocking area 29a at the 11 o'clock position in the hour wheel 27) align with the detection position P. Thus, each time the center wheel 25 makes one rotation or 360 steps, the aperture 28 at the reference, 0 degree or 00 minute position in the center wheel 25 coincides with the detection position P.
When the center wheel 25 rotates 360 steps or one rotation at a time after the reference or 0 degree position in the center wheel 25 is detected, the hour wheel 27 rotates 30 degrees at a time. Thus, even if the detection unit 13 does not detect light each time the center wheel 25 rotates one step, the rotational position of the hour wheel 27 can be detected if the detection unit 13 tries to detect light only when the center wheel 25 makes one rotation. At this time, even if the detection unit 13 tries to detect light by rotating the center wheel 25 by 360 steps at a time from the state of
When the center wheel 25 is further rotated by 360 degrees from this “11-o'clock 00-minute position”, the aperture 29 at the reference or 0-o'clock position in the hour wheel 27 aligns with the detection position P and the detection unit 13 can detect light. That aperture 29 in the hour wheel 27 at this time is at the reference or 0-o'clock 00-minute position. Thus, each time the center wheel 25 rotates by 360 degrees or makes one rotation from the state in which the detection unit 13 can detect light, the detection unit 13 tries to detect light. Then, when the position in the hour wheel 25 (
Referring to
First, referring to
If at this time the state of
When the detection unit 13 cannot detect light, the seconds wheel 20 is rotated further 2 steps, thereby causing the detection unit 13 to try to detect light. As shown in
Subsequently, the detection unit 12 tries to detect light each time the seconds wheel 20 is rotated by 2 steps. As shown
If the detection unit 13 can detect light in next 2 steps, it can be said that the aperture 21a in the seconds wheel 20 has aligned with the detection position P. Thus, it will be seen that the position of the aperture 21a is its reference or 00-seconds position, as shown in
Then, referring to
At this time, when the seconds wheel 20 is rotated by 2 steps at a time, thereby causing the detection unit 13 to detect light each time, the state changes from that of
The basic seconds wheel position detecting method is that if the detection unit 13 tries to detect light, it encounters four non-detection events successively and then detects light in next 2 steps, the position of the aperture in the seconds wheel 20 at this time is a reference position in the seconds wheel 20. In view of this method, in the state of
Thus, if the detection unit 13 cannot detect light successively five times each time the seconds wheel 20 rotates 2 steps, it will be seen that either the aperture 28 in the center wheels 25 or any of the apertures 29 in hour wheel 27 is offset from the detection position P. In this state, it is unknown if the aperture 21 in the seconds wheel 10 aligns wholly or partially with the detection position P.
Since it is seen at this point that either the apertures 28 in the center wheels 25 or any of the apertures 29 in the hour wheel 27 is offset from the detection position P, a trial will be made of a basic process for detecting the reference positions in the center and hour wheel 25 and 27. To this end, the seconds wheel 20 is rotated one step at a time, thereby causing the detection unit 13 to detect light. Therefore, when the state of the center and hour wheels 25 and 27 changes from that of
Thus, it is seen that the reference or 00-minute position in the center wheel 25 has aligned with the detection position P. At this time, it is unknown at which rotational positions the seconds and hour wheels 20 and 27 are. In this case, the detection unit 13 can detect light. Thus, a basic seconds hand position detecting process for detecting the reference position in the seconds wheel 20 is tried by moving the seconds wheel 20 to the position of
Then, when the center wheel 25 is rotated 360 degrees or one rotation at a time, the respective apertures 29 in the hour wheel 27 align sequentially with the detection position P. The detection unit 13 can detect light. Thus, when the center wheel 25 is further rotated 360 degrees from the state (or 11 o'clock position) where the detection unit 13 cannot detect light, the reference or 0-o'clock position in the hour wheel 27 aligns with the detection position P. Thus, the respective reference positions in all the seconds, center and hour wheels 20, 25 and 27 are at the 0-o'clock 00-minute 00-second position which aligns with the detection position P.
Then, referring to
Therefore, the basic hand position detection for the seconds wheel 20 will be further performed. The conditions for detecting the reference position in the seconds wheel are that the detection unit 13 tries to detect light each time the seconds wheel 20 rotates 2 steps at a time, encounters four successive non-detection events, and then detects light successfully in next 2 steps. Thus, as shown in
In this state, it is determined that the aperture 28 in the seconds wheel 25 is offset from the detection position P and then a basic position detecting process for detecting the reference positions in the center and hour wheels 25 and 27 is tried by rotating the center wheel 25 one step at a time. As shown in
If the seconds wheel 20 is rotated 180 degrees or a half rotation when the aperture 21 in the seconds wheel 20 aligns neither wholly nor partially with the detection position P, it is assumed that the aperture 21 necessarily aligns wholly or partially with detection position P, as shown in
Referring to
Then, when the seconds wheel 20 rotates further one step (or in all 2 steps or 12 degrees) to come to a 2 seconds position, the aperture 21a in the seconds wheel 20 moves completely away from the detection position P and the first light blocking area 21d covers the detection position P, as shown in
Further, the seconds wheel 20 rotates one step at a time and the detection unit 13 tries to detect light at every 2 steps. At this time, the first light blocking area 21d of the seconds wheel 20 continuously covers the detection unit 13, as shown at 4 and 6 seconds positions in
Then, when the seconds wheel 20 rotates further 2 steps from this state, and as shown at an 8 seconds position in
Then, when the seconds wheel 20 rotates by further 2 steps or 10 seconds elapses, the arcuate aperture 21b in the seconds wheel 20 aligns partially with the detection position P and the detection unit 13 can detect light, as shown in
Then, referring to
The circuit further comprises a power supply 40 which includes a solar panel 9 (
Then, referring to
When this process starts, the counted number of non-detection events which the detection unit 13 has encountered so far is cleared, thereby resetting a non-detection flag bit to 0 (step S1). Then, the seconds wheel 20 is rotated 2 steps or 12 degrees (step S2). Further, the light emission element 31 of the detection unit 13 is caused to emit light (step S3) and then it is determined if the photo detection element 32 has received light from the light emission element 31 or if the detection unit 13 has detected light (step S4).
When any one of the apertures 21a, 21b and 21c in the seconds wheel 20 aligns wholly or partially with the detection position P, it is determined that the photo detection element 32 has received light from the light emission element 31 and that the detection unit 13 has detected light. Then, control returns to the step S1 and then repeats the above operations of steps S1-S4 until one of the light blocking areas 21d-21f in the seconds wheel 20 blocks or covers the detection position P.
When the seconds wheel 20 rotates 2 steps at a time until any of the apertures 21a, 21b and 21c in the seconds wheel 20 is offset from the detection position P and one of the light blocking areas 21d-21f in the seconds wheel 20 covers the detection position P, the photo detection element 32 receives no light from the light emission element 31. This state is counted up as one non-detection event, thereby setting the non-detection flag bit to “1” (step S5). Then, it is determined if four non-detection events have occurred successively to the detection unit 13 (step S6).
This is because when the detection unit 13 detects light as shown in
Similarly, since in the state of
Then, the seconds wheel 20 is rotated 2 steps (step S7), the light emission element 31 is caused to emit light (step S8), and then it is determined if the photo detection unit 32 has received light from the light emission element 31 (step S9). If so, it can be said that the aperture 21a in the seconds wheel 20 has aligned with the detection position P. Thus, it is determined that the reference or 00 seconds position in the seconds wheel 20 has been detected. Then, a hand position correction process is performed, thereby returning the seconds, center and hour hands 2, 3, and 4 to the current time (step S10). Thus, the watch is returned to its normal hand rotating operation, thereby terminating this process.
In the step S9, assume that the respective apertures 28 and 30 in the center and intermediate wheel 25 and 23 and a relevant one of the apertures 29 in the hour wheel 27 have aligned with the detection position P and are at a stop there. Thus, the detection unit 13 necessarily detects light. However, if the respective apertures 28, 29 and 30 in the center, hour and intermediate wheel 25, 27 and 23 are offset or away from the detection position P, the detection unit 13 detects no light.
Referring to
When this process starts, the center wheel 25 is rotated clockwise one step or degree (step S12), the light emission element 31 is caused to emit light (step S13), and then it is determined if the photo detection element 32 has received light from the light emission element 31 (step S14). If not, the control repeats the steps S12-S14 until the seconds wheel 25 is rotated 360 degrees or one hour (step S15).
Unless the detection unit 13 detects light even when the center wheel 25 rotates 360 degrees (or one hour), it is determined that the aperture 21 in the seconds wheel 20 is away from the detection position P. Thus, the seconds wheel 20 is rotated 30 steps (or 180 degrees), thereby causing the aperture 21 in the seconds wheel 20 to align wholly or partially with the detection position P (step S16). Then, the steps S12-S15 are repeated until the seconds wheel 25 is rotated 360 degrees again from this state.
When the detection unit 13 detects light in the step S14, it is determined that the reference position in the center wheel 25 has aligned with the detection position P. At this time, however it is necessary to confirm if this determination is correct. Assume that as shown in
To avoid this situation, the center wheel 25 is returned 20 steps counterclockwise from its rotational position where the detection unit 13 detected light in the step S14, or 14 degrees or more necessary for the aperture 28 in the center wheel 25 to move substantially completely away from the detection position P (step S17). Then, the center wheel 25 is fast rotated clockwise (step S18). This eliminates any possible backlash between the center and intermediate wheels 25 and 23 and places the center wheel 25 at a position where the center wheel 25 has been returned 14 steps from the position of the center wheel 25 where the detection unit 13 detected light.
That is, when the center wheel 25 is returned 14 steps counterclockwise from the detection position P, the aperture 28 in the center wheel 25 should be completely away from the detection position. Then, the center wheel 25 is again rotated clockwise one step at a time from the position where the center wheel 25 has been returned (step S19); the light emission element 31 of the detection unit 13 is caused to emit light (step S20); and then it is determined if the photo detection element 32 of the detection unit 13 has received the light from the light emission element 13, and hence if the detection unit 13 has detected light (step S21).
Unless the detection unit 13 detects light in the step S21, the steps S19-S21 are repeated until the center wheel 25 is rotated 14 steps (step S22). At this time, the detection unit 13 should detect light necessarily in the step S21. Otherwise, a hand position detection error is reported with a stop position of the seconds hand 2 or buzzer sound (step S23). If the detection unit 13 detects light in the step S21, it is determined that the position of the aperture 28 in the center wheel 25 where the detection unit 13 detected light this time is the reference or 00 minute position in the center wheel 25 (step S24). Then, this process is terminated.
Then, referring to
When this process starts, the center wheel 25, where its aperture 28 has aligned with the detection position P, is rotated 360 degrees, thereby rotating the hour wheel 27 by 30 degrees (step S25). The light emission element 31 of the detection unit 13 is then caused to emit light (step S26), and then it is determined if the photo detection element 32 has received light from the light emission element 31. That is, it is determined if one of the apertures 29 in the hour wheel 27 has aligned with the detection position P and the detection unit 13 has detected light (step S27).
At this time, the hour wheel 27 has 11 circular apertures 29 therein provided at angular intervals of 30 degrees along the circumference thereof with the fourth light blocking area 29a at the 11 o'clock position. Thus, when the center wheel 25 rotates 360 degrees and the hour wheel 27 rotates 30 degrees, a relevant one of the apertures 29 in the hour wheel 27 aligns with the detection position P and the detection unit 13 detects light. Thus, when the center wheel 25 makes a complete rotation a required number of times, the apertures 29 in the hour wheel 27 align sequentially with the detection position P, and the detection unit 13 detects light accordingly, as shown in
As shown in
As shown in
Referring to
When this three-hand position detecting process starts, the seconds hand position detecting process of
At this time, none of the rotational positions in the seconds, center and hour wheels 20, 25 and 27 is known. When the photo detection element 32 receives light from the photoemission element 31 and the detection unit 13 detects light, the control returns to the step S31 to repeat the steps S31-S34 until one of the light blocking areas 21d-21f of the seconds wheel 20 covers the detection position P.
When the detection unit 13 detects light in the step S34, a relevant one of the apertures 21a, 21b and 21c in the seconds wheel 20; the apertures 28 and 30 in the center and intermediate wheels 25 and 23, respectively; and a relevant one of the apertures 29 in the hour wheel 27 have all aligned accidentally with the detection position P. At this time, the reference or 00 minute position in the center wheel 25 has aligned with the detection position P, but the rotational positions of the seconds and hour wheels 20 and 27 are unknown. Thus, first, the rotational position of the seconds wheel 20 is detected. To this end, the steps S31-S34 are repeated until any one of the light blocking areas 21d-21f in the seconds wheel 20 covers the detection position P, thereby disabling the detection unit 13 from detecting light.
When one of the light blocking areas 21d-21f in the seconds wheel 20 covers the detection position P, thereby disabling the detection unit 13 from detecting light in the step S34, this non-detection event having occurred to the detection unit 13 is counted by the counter and the non-detection flag bit is set to 1 (step S35). Then, it is determined if four non-detection events have occurred successively (step 36). Then, the steps S32-S36 are repeated until in the step S36 four non-detection events occur successively to the detection unit 13 due to the light blocking area 21e in the seconds wheel 20 covering the detection position P. When the four non-detection events occur successively to the detection unit 13, the seconds wheel 20 is rotated 2 steps (step S37), and the light emission element 31 is caused to emit light (step S38). Then, it is determined if the photo detection element 32 has received light from the light emission element 31, and hence if the detection unit 13 has detected light (step S39).
If the detection unit 13 has detected light in the step S39, it is determined that the reference or 00 minute position in the center wheel 25 has aligned with the detection position P, and that the aperture 28 in the center wheel 25, a relevant one of the apertures 29 in the hour wheel 27, and the aperture 21a in the seconds wheel 20 have aligned with the detection position P. Thus, it is determined that the respective reference positions in the seconds and center wheels 20 and 25 are at the 00-minute 00 seconds position. Then, the control passes to a step S80 for a hour hand position detecting process.
When in the step S39 the detection unit 13 detects no light, five non-detection events have occurred successively to the detection unit 13 even when the circular aperture 21a in the seconds wheel 20 has aligned with the detection position P, as shown in
As shown in
When the detection unit 13 has detected light in the step S43, it will be seen that one of the apertures 21a, 21b and 21c in the seconds wheel 20; the apertures 28 and 30 in the center and intermediate wheels 25 and 23, respectively; and a relevant one of the apertures 29 in the hour wheel 27 have all aligned wholly or partially with the detection position P. It will also be seen that before the center wheel 25 started to be rotated in the step S41, the apertures in the center and hour wheels 25 and 27 has been offset from the detection position P. Since it is assumed that the detection unit 13 has now detected light, it is determined that the reference or 00-minute position in the center wheel 25 has aligned with the detection position P. Then the control passes to the step S71 to perform a center hand position confirming process to confirm if this determination is correct.
If the detection unit 13 detects no light even when the center wheel 25 is rotated 360 degrees in the step S44, it is determined that as shown in
When in the step S47 the detection unit 13 has detected light, it will be seen that a relevant one of the apertures 21a, 21b and 21c in the seconds wheel 20; the apertures 28 and 30 in the center and intermediate wheels 25 and 23, respectively; and a relevant one of the apertures 29 in the hour wheel 27 have aligned wholly or partially with the detection position P, and that before the seconds wheel 20 started to be rotated in the step S45, the seconds wheel 20 has been offset from the detection position P. Also in this case, since it is assumed that in the step S47 the detection unit 13 has detected light, it is determined that the reference or 00 minute position in the center wheel 25 has aligned with the detection position P and then the control passes to a center hand position confirming process in the step S71.
However, if the detection unit 13 detects no light in the step S47 even when the seconds wheel 20 is rotated 30 steps or 180 degrees in the step S45, it is determined that as shown in
Then, the light emission element 31 is caused to emit light (step S49), and then it is determined if the photo detection element 32 has received light from the light emission element 31, and hence if the detection unit 13 has detected light (step S50). If not, the center wheel 25 is rotated one step at a time, and then it is determined if the center wheel 25 has rotated 360 degrees (step S51). If not, the steps S48-S51 are repeated until the center wheel 25 makes one rotation.
When the detection unit 13 detects light in the step S50, it will be seen that a relevant one of the apertures 21a, 21b and 21c in the seconds wheel 20; the apertures 28 and 30 in the center and intermediate wheels 25 and 23, respectively; and a relevant one of the apertures 29 in the hour wheel 27 have all aligned wholly or partially with the detection position P, and that before the center wheel 25 started to rotate in the step S50, the aperture in the center wheel 25 had been offset from the detection position P. Since it is assumed that the detection unit 13 has now detected light in the step S50, it is determined that the reference or 00 minute position in the center wheel 25 has aligned with the detection position P. Then, the control passes to the step S71 for the center hand position confirming process.
If the detection unit 13 detects no light in the step S50 even when the center wheel 25 is rotated 360 degrees in the step S51, then it is determined that any of the apertures 29 in the hour wheel 27 is offset from the detection position P and that the light blocking area 29a in the hour wheel 27 covers the detection position P even when a relevant one of the apertures 21a, 21b and 21c in the seconds wheel 20; and the apertures 28 and 30 in the center and intermediate wheels 25 and 23, respectively, align wholly or partially with the detection position P, as shown in
At this time, it is not seen that any of the apertures 21a, 21b and 21c in the second wheel 20 has aligned wholly or partially with the detection position P. Thus, the seconds wheel 20 is rotated 30 steps or 180 degrees (step S52), and the light emission element 31 is caused to emit light (step S53). Then, it is determined if the photo detection element 32 has received light, and hence if the detection unit 13 has detected light (step S54).
When the detection unit 13 has detected light at this time, it will be seen that a relevant one of the apertures 21a, 21b and 21c of the seconds wheel 20; the apertures 21 and 28 in the seconds and center wheels 20 and 25, respectively; a relevant one of the apertures 29 in the hour wheel 27; and the aperture 30 in the intermediate wheel 23 have all aligned wholly or partially with the detection position P. It will also be seen that the light blocking area 29a of the hour wheel 27 does not cover the detection position P, and that before the seconds wheel 20 started to be rotated in the step S52, the aperture 21 in the seconds wheel 20 has been offset from the detection position P. Also, since it is assumed that the detection unit 13 has detected light, it is determined that at this time the reference or 00 minute position in the center wheel 25 has aligned with the detection position P. Then, the control passes to the step S71 for the center hand position confirming process.
When the detection unit 13 does not detect light in the step S54, it is determined that the fourth light blocking are 29a of the hour wheel 27 has blocked the detection position P, as shown in
When the detection unit 13 has detected light in the step S57, a relevant one of the apertures 21a, 21b and 21c of the seconds wheel 20; the apertures 28 in the center wheel 25; a relevant one of the apertures 29 in the hour wheel 27; and the aperture 30 in the intermediate wheel 23 have aligned all wholly or partially with the detection position P. Thus, the light blocking area 29a of the hour wheel 27 does not block the detection position P and before the center wheel 25 started to be rotated in the step S55, the aperture 28 in the center wheel 25 has been offset from the detection position P. Since it is now assumed that in the step S57 the detection unit 13 has detected light, it is determined that the reference or 00 minute position in the center wheel 25 has aligned with the detection position P. Then, the control passes to the step S71 for the center hand position confirming process.
If the detection unit 13 has detected no light in the step S57 even when the center wheel 25 is rotated 360 degrees in the step S58, it is conjectured that the light blocking area 29 of the hour wheel 27 has blocked the detection position P and hence that the hour wheel 27 is at the 11 o'clock position. In order to confirm if this conjecture is correct, the seconds wheel 20 is rotated 30 steps or 180 degrees (step S59); the light emission element 31 is caused to emit light (step S60); and then it is determined if the photo detection element 32 has received light from the light emission element 31 and hence if the detection unit 13 has detected light (step S61).
If at this time the detection unit 13 has detected light, a relevant one of the apertures 21a, 21b and 21c of the seconds wheel 20; the aperture 28 in the center wheel 25, a relevant one of apertures 29 in the hour wheel 27, and the aperture 30 in the intermediate wheel 23 have all aligned wholly or partially with the detection position P. Thus, it will be seen that the 11 o'clock position of the hour wheel 27 is not at the detection position P and that before the seconds wheel 20 started to be rotated in the step S59 the aperture in the seconds wheel 20 had been offset from the detection position P. Also, since it is now assumed that the detection unit 13 has detected light, it is determined that the reference or 00 minute position in the center wheel 25 has aligned with the detection position P. Then, the control passes to the step S70 for the center hand position confirming process.
When in the step S61 the detection unit 13 detects no light, it is determined that the light blocking area 29a of the hour wheel 27 has blocked the detection position P. Thus, the center wheel 25 is rotated one step (step S62). Then, the light emission element 31 is caused to emit light (step S63) and it is determined if the photo detection element 32 has received light from the light emission element 31 and hence if the detection unit 13 has detected light (step S64).
If at this time the detection unit 13 detects no light, the center wheel 25 is rotated one step at a time and then it is determined if the center wheel 25 has rotated 360 degrees (step S65). If not, the steps S62-S64 are repeated until the center wheel 25 rotates 360 degrees. If the detection unit 13 detects no light even when the steps S62-S64 are repeated, a hand position detection error is reported with a stop position of the seconds hand 2 or buzzer sound (step S66). When in the step S64 the detection unit 13 detects light, it is determined that the reference or 0 o'clock and 00 minute positions in the hour and center wheels 27 and 25, respectively, have aligned with the detection position P. Then, the control passes to the step S71 for the center hand position confirming process.
As shown in
That is, the center wheel 25 has been returned 14 steps or 12 degrees or more necessary for the aperture 28 in the center wheel 25 to move away substantially completely from the detection position P. Then, the center wheel 25 is again rotated clockwise one step from its position where the center wheel 25 has been returned (step S73). Then, the light emission element 31 is caused to emit light (step S74) and it is determined if the photo detection element 32 has received light from the light emission element 31 and hence if the detection unit 13 has detected light (step S75).
Unless the detection unit 13 detects light in the step S75, the steps S73-S75 are repeated until the center wheel 25 is rotated by 14 steps (step S76). In the step S75 the detection unit 13 should necessarily detects light. However, otherwise, a hand position detection error is reported with a stop position of the seconds hand 2 or buzzer sound (step S77). If in the step S75 the detection unit 13 detects light, it is determined that the position of the aperture 28 in the center wheel 25 which has aligned at this time with the detection position P is the reference or 00 minute position in the center wheel 25 (step S78).
Also in this case, it is unclear if the reference position in the seconds wheel 20 has aligned with the detection position P. Thus, the control returns to the step S31 for the second hand position detecting process to perform the steps S31-S39, thereby rotating the seconds wheel 20 so that its reference position aligns with the 00-minute 00-seconds position or the detection position P. Then, the control passes to a step S80 for the hour hand position detecting process shown in
At this time, when the detection unit 13 detects light each time the hour wheel 27 rotates 30 degrees, the respective apertures 29 in the hour wheel 27 sequentially align with the detection position P and the hour wheel 27 comes to its related hour position. Thus, the control returns to the step S80 to repeat the steps S80-S82 until the light blocking area 29a at the 11 o'clock position in the hour wheel 27 covers the detection position P. Unless the detection unit 13 detect light, it is determined that the light blocking area 29a of the hour wheel 27 has blocked the detection position P and that the 11 o'clock position of the hour wheel 27 has aligned the 11 o'clock position with the detection position P.
In order to confirm if this determination is correct, the center wheel 25 is again rotated 360 degrees, thereby rotating the hour wheel 27 30 degrees (step S83). Then, the light emission element 31 is caused to emit light (step S84). It is then determined if the photo detection element 32 has received light from the light emission element 31 and hence if the detection unit 13 has detected light (step S85). If so, it is determined that the reference positions in all the seconds, center and hour wheels 20, 25 and 27 are at the 0-o'clock 00-minute 00-seconds position which has aligned wholly or partially with the detection position P. Thus, the seconds, center and hour hands 2, 3 and 4 are set to the exact current time (step S86) and then switched over to the normal driving operation, thereby terminating this process. In the step S85, the detection unit 13 should necessarily detect light. Otherwise, a hand position detection error is reported with a stop position of the seconds hand 2 or buzzer sound (step S87).
Then, referring to
If this process is performed at every hour on the hour, it would coincide with generation of a time/alarm signal or other various operations expected to be performed. Thus, this process is preferably performed several minutes before each of 1-12 o'clock hours. In this case, the hour wheel 27 rotates one degree per 12 minutes. Thus, even when this process is performed 10 minutes or so offset from every hour on the hour, the aperture 29 does not completely move away from the detection position P. Therefore, the detection unit can detect light.
When the detection unit 13 detects light in the process, the hour hand 4 is regarded as being set correctly. Then, it is confirmed if the seconds hand 2 and 3 are set correctly. In this case, this process can be confirmed only when the center hand 3 is fast or slow by less than 60 minutes from the related starting time. When 10 seconds elapses from the related starting time, the center wheel 25 is rotated one step and thus the intermediate wheel 23 rotates 30 degrees, thereby blocking the detection position P. Thus, it is necessary to confirm in 10 seconds from the related starting time if the seconds hand 2 is fast or slow.
To this end, the hand position confirming process starts at the 55th minute of every hour excluding 11 and 22 o'clock hours. Then, the light emission element 31 is caused to emit light (step S90). Then, it is determined if the photo detection element 32 has received light from the light emission element 31 and hence if the detection unit 13 has detected light (step S91). If not, it is determined that at least one of the seconds, center and hour hands 2, 3 and 4 is fast or slow and then the control passes to the three-hand position detecting process.
If the detection unit 13 detects light, it is determined that one of the apertures 21a, 21b and 21c in the seconds wheel 20 has aligned wholly or partially with the detection position P. Then, the counted number of non-detection events having occurred to the detection unit 13 and counted so far is cleared, thereby resetting the non-detection flag bit to zero (step S92). Then, the seconds wheel 20 rotates one step or 6 degrees in the normal manner, thereby causing the seconds hand 2 to rotate around the dial in the normal manner (step S93). Then, it is determined if the seconds wheel 20 has rotated 2 steps or 12 degrees (step S94). When the seconds wheel 20 rotates only one step or 6 degrees, the circular aperture 21a in the seconds wheel 20 does not completely move away from the detection position P. Thus, the detection 13 tries to detect light each time the seconds wheel 20 rotates 2 steps.
Unless in the step S94 the seconds wheel 20 rotates 2 steps, the seconds hand 2 is caused to rotate around the dial one step (or 6 degrees) at a time in the normal manner until the seconds wheel 20 rotates 2 steps, whereupon it is determined at which of 2, 4, 6 and 8 seconds positions the light emission element 31 is (step S95). In this case, since the first stepping motor 17 cannot operate correctly due to external factors such as external magnetic field, it can occur that the seconds hand 2 is not at any of the 2, 4, 6 and 8 seconds positions. In this case, a hand position detection error is reported with a stop position of the seconds hand 2 and/or buzzer sound (step S96).
If it is determined in the step S95 that the seconds hand 2 is at one of the 2, 4, 6 and 8 seconds positions, the light emission element 31 of the detection 13 is caused to emit light without being influenced by external factors such as external magnetic field (step S97). Then, it is determined if the photo detection element 32 has received light from the light emission element 31 and hence if the detection unit 13 has detected light (S98). When at this time the detection unit 13 detects light, a relevant one of the apertures 21a, 21b and 21c in the seconds wheel 20 has aligned wholly or partially with the detection position P. Hence, it is determined that the seconds wheel 20 was not set exactly before the step S93 and then the control passes to the three-hand position detecting process.
When in the step S98 the detection unit 13 detects no light, it is determined that as shown in
If in the step S100 three non-detection events have occurred successively when 6 seconds elapses from the 55th minute of every hour, which brings about, for example, a change in the state from
When the seconds wheel 20 rotates 2 steps, the light emission element 31 is caused to emit light (step S103). Then, it is determined if the photo detection element 32 has received light from the light emission element 31 and hence if the detection unit 13 has detected light when 8 seconds elapses from the 55th minute of every hour (step S104). If not, it is determined that the light blocking area 21e of the seconds wheel 20 has blocked the detection position P and hence that the seconds wheel 20 is not at its correct rotational position. Thus, the control passes to the three-hand position detecting process. As shown in
Next, referring to
More particularly, this error processing starts, the hand position confirming process involving the steps S90-S104 is performed (step S110). Then, the control can pass to the three-hand position detection process at the respective steps S91, S98 and S104 to determine if a hand position detection error has occurred in the three-hand position detection process and the hand position confirming process (step S111). If not, an error counter (not shown) is cleared to zero (step S112) and then the hand position confirming process is performed at the 55th minute of every hour on the hour as usual (step S113).
When it is determined in the step S111 that a hand position detection error has occurred, the error counter counts this error event as one (step S114) and then determines if such errors have occurred successively a predetermined number of times (in this embodiment, three times) so far (step S115). If not, the control returns to the step S110 to repeat the steps S110 to S115 until hand position detection errors occur successively three times.
When it is determined in the step S115 that the hand position detection errors have occurred successively three times, the contents of those errors are stored in the RAM 37 and then the hand position detection process including the hand position confirming process involving the steps S90-S104 of
Next, referring to
Error No. 0: This indicates that the hands are detected at their correct positions and that the seconds hand 2 is stopped at a 55 seconds position.
Error No. 1: In the center hand position confirming process of
Error No. 2: In a section E2, the steps S31-S36 are performed to confirm that the number of places, where no light is detected successively four times when the seconds hand 2 makes a rotation in 60 steps, 2 steps at a time, is one in the three-hand position detection process of
Error No. 3: In a section E3, each time the center hand 3 is rotated 360 degrees, the steps S80-S85 are performed to confirm optical detection of a respective one of the 11 apertures 29 provided at angular intervals of 30 degrees along the periphery of the hour wheel 27 in the three-hand position detection process of
Error No. 4: This error occurs in a section E6 when no light is detected in the step S39 of
Error No. 5: In a section E7, the steps S93-S98 are performed to confirm if the seconds hand 2 has been rotated 2 steps in the hand position confirming process which is performed at the 55th minute of every hour in the normal hand rotating operation of
Error No. 6: This error occurs when light has been detected successively 11 times and then not in a next trial in the steps S52-S66 in a period E5 of the three-hand position detection process of
Error No. 8: This error can occur after at least one light detection has been performed successfully in the three-hand position detecting process of
Error No. D: This error occurs when no light is detected because any of the light emission element 31 and the photo detection element 32 of the detection unit 13 is broken, thereby making light detection impossible. In this case, the seconds hand 2 is stopped at a 39 seconds position. Error No. E: This error occurs when no light can be detected because the CPU 35 of the wristwatch is broken or some electric parts are badly soldered on the circuit board. In this case, the seconds hand 2 is stopped at a 42 seconds position. The above-mentioned errors Nos. D and E occur in the circuit system.
As described above, the hand position detecting device comprises the detection unit 13 for detecting passage of light through the plurality of apertures 21, 28, 29 and 30 provided in the seconds, center, hour and intermediate wheels 20, 25, 27 and 30, respectively, the wheels 20, 25 and 30 having the hands 2, 3 and 4, respectively; the position detecting unit (CPU 35, steps S31-S86) for detecting the respective positions of the hand wheels on the basis of a transmitted state of light detected by the detection unit 13; and the position detection controlling unit (CPU 35, S110-S117) for stopping the position detecting unit from detecting the hand wheel positions until a predetermined time when the position detecting unit has failed to detect the positions of the hand wheels successively the predetermined number of times. Thus, when the respective positions cannot be detected, useless consumption of battery power is prevented which would otherwise occur.
Assume that hand position detection errors in which the position detection unit (CPU 35) cannot detect the respective positions of the seconds hand 2, center hand 3 and hour hand 4 occur successively a predetermined number of (3) times (steps S31-S86). In this case, the position detection controlling unit (CPU 35) stops the position detection unit from detecting the respective positions of the seconds hand 2, center hand 3 and hour hand 4 until the predetermined time, for example, the 55th minute of the next 10 o'clock hour (steps S110-S117). This prevents unnecessary repetition of detection of the positions of these hands 2, 3 and 4 which would otherwise be performed, and hence useless consumption of battery power.
In this case, the position detection error reporting unit (CPU 35, S66, S77, S87 and S96) is responsive to the position detecting unit (CPU 35, S31-S86) failing to detect the respective positions of the seconds, center and hour hands 2, 3 and 4 to report a hand position detection error with indication of a stop position of the seconds hand 2 or buzzer sound. Thus, when a position detection error occurs, the error can be reported rapidly.
This hand position detection device comprises the plurality of push-button switches SW which compose an operation unit to be operated to select one of the normal hand rotating mode in which the seconds, center and hour hands 2, 3 and 4 are normally rotated around the dial and the error display mode in which the contents of a hand position detection error occurring are displayed. Thus, when, for example, the three predetermined ones of the plurality of push-button switches SW are depressed simultaneously in the normal hand rotating mode, the error display mode is selected, thereby displaying the contents of the hand position detection error. In this error display mode, the contents of the error are indicated by the stop position of the seconds hand 2. Thus, the contents of the error can be seen easily and hence hand position adjustment or repair can be performed easily and rapidly.
The hand position detection device comprises the seconds wheel 20 with the aperture 21, the center wheel 25 with the aperture 28, and the hour wheel 27 with the 11 apertures 29 provided at the corresponding 1-11 o'clock positions excluding at a specified o'clock position along the periphery thereof. Thus, the position detection unit (CPU 35) detects the respective positions of the seconds, center and hour hands 2, 3 and 4 several minutes before every hour on the hour or at the 55th minute of every hour on the hour, thereby achieving good detection (steps S31-S86). If the hand position detection unit detects the respective positions of these hands 2, 3 and 4 at every hour on the hour, this processing would coincide with generation of a time signal and/or an alarm which are expected to be performed, thereby decreasing the battery power which would influence the position detection adversely.
In this hand position detection device, the position detection controlling unit (CPU 35) stops the detection of the respective positions of the second, center and hour hands 2, 3 and 4 (steps S110-S116) for a time period ranging from when the last of the predetermined number of (in this embodiment, 3) successive errors has occurred to several minutes before the specified next 11 o'clock hour, or more particularly, the 55th minute of the specified next 10 o'clock hour. Thus, when the positions of the seconds, center and hour hands 2, 3 and 4 cannot be detected, they are not required to be detected at the 55th minute of every hour. Since the detection of the positions of the seconds, center and hour hands 2, 3 and 4 is normally performed at the 55th minute of every hour, it is stopped for a maximum of about 12 hours, thereby preventing useless consumption of battery power, which would otherwise occur.
(Modification)
In the above embodiment, the center hand position detecting unit is illustrated as configured such that the center wheel 25 is rotated one step at a time in a predetermined direction to a position where the aperture 28 in the center wheel 25 aligns with the aperture 30 in the intermediate wheel 23, thereby causing the detection unit 13 to detect light passing through the aligning apertures 28 and 30 in the center and intermediate wheels 25 and 23; then the center wheel 25 is returned 20 steps from the position of the aperture 28 in the center wheel 25 where the detection unit 13 detected light; then the center wheel 25 is fast rotated 6 steps in the predetermined direction from the position where the center wheel 25 is returned; the center wheel 25 is rotated one step at a time in the predetermined direction from the position where the center wheel 25 was returned 14 steps finally, thereby causing the detection unit 13 to try to detect light; and when the detection unit 13 detects light again at the same position of the aperture 28 in the center wheel 25 where the detection unit 13 detected light, this position is determined as the reference position in the center wheel 25. Alternatively, the center hand position detecting unit may be constituted as a modification which performs a center hand position detecting process, for example, shown in
As shown in
If the detection unit 13 detects no light even when the center wheel 25 rotates 360 degrees for one hour, it is determined that any of the apertures 21a, 21b and 21c in the seconds wheel 20 has aligned neither wholly nor partially with the detection position P. Thus, the seconds wheel 20 is further rotated 30 steps or 180 degrees, thereby causing a relevant one of the apertures 21a, 21b and 21c in the seconds wheel 20 to align wholly or partially with the detection position P (step S126). Then, the control returns to the step S120, thereby clearing the counter which has counted the number of steps of the center wheel 25 counted so far to 0. Then, the step S121-S125 are repeated until the center wheel 25 rotates 360 degrees or one hour by rotating one step at a time.
When the detection unit 13 detects light in the step S124, it is determined that the reference or 00 minute position in the center wheel 25 has aligned with the detection position P, and then the number of steps of the center wheel 25 counted so far is recorded in the RAM 37. Then, it is determined if the number of steps counted is within a predetermined number of (12) steps (S≦12) (step S127). That is, when the center wheel 25 rotates 12 steps, its aperture 28 is substantially completely away from the detection position P, but the detection unit 13 can detect light due to possible manufacturing errors involving, for example, the assembly of the wristwatch.
Thus, if the number of steps the center wheel 25 has been rotated so far when the detection unit 13 detected light in the step S127 is equal to or within 12, it is necessary to confirm if the determination that the reference position in the center wheel 25 has aligned with the detection position P is correct. To this end, the center wheel 25 is returned counterclockwise 12 steps or degrees or more from the position of the aperture 28 in the center wheel 25 where the detection unit 13 detected light in the step S127 (step S128), thereby moving the aperture 28 in the center wheel 25 substantially completely away from the detection position P. The center wheel 25 is again rotated clockwise one step from the position to which the center wheel 25 has been returned (step S129). Then, the light emission element 31 is caused to emit light (step S130), and then it is determined if the photo detection unit 32 has received light from the light emission element 31 and hence if the detection unit 13 has detected light (step S131).
Unless in the step S131 the detection unit 13 detects light, the steps S128-S131 are repeated until the center wheel 25 rotates 12 steps or more (step S132). When the center wheel 25 rotates 12 steps in the step S132, the detection unit 13 should necessarily detect light in the step S131. Otherwise, a hand position detection error is reported with indication of a stop position of the seconds hand 2 or buzzer sound (step S133). If the detection unit 13 detects light in the step S131, it is determined that the position of the aperture 28 in the center wheel 25 at this time is the reference or 00-minute position in the center wheel 25 (step S134), thereby terminating this process.
When it is determined in the step S127 that the center wheel 25 has been rotated the predetermined number of (12) steps or more, the apertures 30 and 28 in the intermediate and center wheels 23 and 25 have aligned with the detection position P after the intermediate wheel 23 has made one rotation or more and the aperture 28 in the center wheel 25 has been rotated 12 degrees or more. Thus, it can be said that the center and intermediate wheels 25 and 23 have encountered the states of
As described above, the modification of the hand position detecting device includes the CPU 35 which composes counting means which counts the number of steps each of which the center wheel 25 rotates at a time (step S122); the RAM 37 which composes a storage which stores the number of steps, each of which the center wheel 25 has been rotated at a time until the detection unit 13 detects light; and the CPU 35 which also composes resetting means which resets the counter when the detection unit 13 detects no light even when the center wheel 25 makes one rotation (step S120). Thus, when the seconds wheel 20 blocks or covers the detection position P and the detection unit 13 optically detects no aperture 28 in the seconds wheel 25, the resetting means resets and clears the number of steps counted so far so as to allow to correctly count the number of steps each of which the center wheel 25 has been rotated at a time. Thus, it can be determined if the counted number of steps stored indicates the predetermined number of steps.
In this modification, further, the CPU 35 which also composes the center position determining means which determines the position of the aperture in the center wheel 25, where the detection unit 13 detected light, as the reference position in the center wheel 25 (step S127), by omitting the respective processings to be performed in the center hand returning means and the center hand position determining means, when the number of steps stored in the RAM 37, each of which steps the center wheel 25 has been rotated at a time, is a predetermined number of (12) step or more. Thus, when it is determined that the number of steps stored in the RAM 37 is a predetermined number of (12) steps or more, the apertures 30 and 28 in the intermediate and center wheels 23 and 25 have aligned with the detection potion P after the intermediate wheel 23 has made one rotation or more and the aperture 28 in the center wheel 25 has been rotated 12 degrees or more. Thus, even if the processes for confirming the center wheel 25, or more particularly the respective processes to be performed by the center hand returning means and the center hand position confirming means (steps S128-S135), are omitted, the reference position in the center wheel 25 is specified accurately.
(First Modification of the Seconds Wheel)
While in the embodiment the seconds wheel 20 is illustrated as having arcuate light-passing apertures 21b and 21c, the seconds wheel 20 may be constructed as shown in a first modification in
In this case, the arcuate aperture 40a adjacent to the circular aperture 21a in the counterclockwise direction extends from approximately 48 degrees to approximately 96 degrees counterclockwise relative to center of the circular aperture 21a, or through a net angular extent of approximately 60 degrees which is 5 times an angle of the circular aperture 21a as viewed from the center of the seconds wheel 20. The arcuate aperture 40b also extends from approximately 120 degrees to approximately 168 degrees counterclockwise relative to the circular aperture 21a, or through a net angular extent of approximately 60 degrees which is 5 times the angle of the circular aperture 21a as viewed from the center of the seconds wheel 20. A fifth light blocking area 42 in the seconds wheel 20 is provided between the arcuate apertures 40a and 40b so as to be diametrically opposed to a part of the arcuate aperture 41a in the seconds wheel 20.
The arcuate aperture 41a adjacent to the circular aperture 21a in the clockwise direction extends from approximately 60 degrees to approximately 96 degrees clockwise relative to the aperture 21a, or through a net angular extent of approximately 48 degrees which is 4 times the angle of the circular aperture 21a as viewed from the center of the seconds wheel 20. The arcuate aperture 41b extends from approximately 120 degrees to approximately 168 degrees clockwise relative to the circular aperture 21a along the periphery of the seconds wheel 20, or through a net angular extent of approximately 60 degrees which is approximately 5 times the angle of the circular aperture 21a as viewed from the center of the seconds wheel 20. A sixth light blocking area 43 is provided between the arcuate apertures 41a and 41b in the seconds wheel 20 so as to be substantially diametrically opposed to the arcuate aperture 40a in the seconds wheel 20.
A first light blocking area 21d is provided between the circular aperture 21a and the arcuate aperture 40a. A second light blocking area 21e is provided between the circular aperture 21a and the arcuate aperture 41a. A third light blocking area 21f is provided between the arcuate apertures 40b and 41b so as to be diametrically opposed to the circular aperture 21a in the seconds wheel 20.
Also in this case, the first light blocking area 21d is provided so as to extend through approximately 48 degrees counterclockwise relative to the circular aperture 21a, or through a net angular extent of approximately 36 degrees which is approximately 3 times the angle of the circular aperture 21a, as viewed from the center of the seconds wheel 20. The first light blocking area 21d also is diametrically opposed to part of the arcuate aperture 41b in the seconds wheel 20. The second light blocking area 21e extends through approximately 60 degrees clockwise relative to the circular aperture 21a, or through a net angular extent of approximately 48 degrees which is approximately 4 times the angle of the circular aperture 21a, as viewed from the center of the seconds wheel 20. The second light blocking area 21e also is diametrically opposed to the arcuate aperture 40b in the seconds wheel 20. Each of the light blocking areas 21f, 42 and 43 is substantially the same size as the circular aperture 21a. The light blocking area 21f is diametrically opposed to the circular aperture 21a in the seconds wheel 20; the light blocking area 42 is diametrically opposed to part of the arcuate aperture 41a; and the light blocking area 43 is diametrically opposed to part of the arcuate aperture 40a.
The arrangement is such that when the seconds wheel 20 rotates 30 steps or 180 degrees from a state in which a relevant one of the light blocking areas 21d, 21f, 42 and 43 has covered the detection position P, a relevant one of the circular aperture 21a and the arcuate apertures 40a, 40b, 41a and 41b aligns wholly or partially with the detection position P. Thus, this modification produces similar advantages to those produced by the previous embodiment. In addition, the light blocking area 42 is provided between the arcuate apertures 40a and 40b and the light blocking area 43 between the arcuate apertures 41a and 41b. Thus, the mechanical strength of the seconds wheel 20 is improved compared to the previous embodiment.
(Second Modification of the Seconds Wheel)
In the above embodiment and the first modification of the seconds wheel 20, the first light blocking area 21d, which indicates a separation between the arcuate aperture 21b and the circular aperture 21a, is illustrated as extending through approximately 48 degrees relative to the circular aperture 21a, or through a net angular extent of approximately 36 degrees which is approximately 3 times the angle of the circular aperture 21a as viewed from the center of the seconds wheel 20. The second light blocking area 21e, which indicates a separation between the circular aperture 21a and the arcuate aperture 21c, is illustrated as extending through approximately 60 degrees relative to the circular aperture 21a, or through a net angular extent of approximately 48 degrees which is approximately 4 times the angle of the circular aperture 21a, as viewed from the center of the seconds wheel 20.
Alternatively, a second modification of the seconds wheel 20 as shown in
Like the first modification, the second modification has the arcuate aperture 21b which is divided into shorter arcuate apertures 40a and 40b with a fifth light blocking area 42 in between. The aperture 40a extends from approximately 36 degrees to approximately 96 degrees counterclockwise relative to the circular aperture 21a, or longer toward the circular aperture 21a by an net angular extent of the angle of the circular aperture 21a as viewed from the center of the seconds wheel 20 than the arcuate aperture 40a in the first modification.
Like the first modification, the second modification has the arcuate aperture 21c which is divided into shorter arcuate apertures 41a and 41b with a fourth light blocking area 43 in between. The aperture 41a adjacent to the circular aperture 21a extends from approximately 264 degrees to approximately 312 degrees counterclockwise relative to the circular aperture 21a, or longer toward the circular aperture 21a by a net angular extent of the angle of the circular aperture 21a, as viewed from the center of the seconds wheel 20, than the arcuate aperture 41a in the first modification.
Also in this case, the first light blocking area 21d between the arcuate aperture 21b and the circular hole 21a is diametrically opposed to part of the arcuate aperture 41b in the seconds wheel 20. The second light blocking area 21e between the arcuate aperture 21c and the circular hole 21a is diametrically opposed to the arcuate aperture 40b in the seconds wheel 20. In addition, the arcuate aperture 21f is diametrically opposed to the circular aperture 21a in the seconds wheel 20; the arcuate aperture 42 is diametrically opposed to the arcuate aperture 41a in the seconds wheel 20; and the arcuate aperture 43 is diametrically opposed to the circular aperture 41a in the seconds wheel 20.
This modification is fabricated such that when the seconds wheel 20 rotates 30 steps or 180 degrees, from the state in which one of the light blocking areas 21d, 21f, 42 and 43 has aligned wholly or partially with the detection position P of the detection unit 13, a relevant one of the circular aperture 21a and the arcuate apertures 40a, 40b, 41a and 41b aligns wholly or partially with the detection position P. Thus, this modification also produces advantages similar to those produced by the embodiment and first modification as well as the following additional advantages.
As described above, the first light blocking area 21d between the arcuate aperture 21b and the circular aperture 21a is provided so as to extend through approximately 36 degrees relative to the circular aperture 21a, or through a net angular extent of approximately 24 degrees which is approximately twice the angle of the circular aperture 21a, as viewed from the center of the seconds wheel 20. Thus, assume that when the seconds wheel 20 rotates one step or 6 degrees at a time in the normal manner and the seconds hand 2 rotates around the dial. In this case, when the seconds wheel 20 rotates four steps or 24 degrees, the first light blocking area 21d passes through the detection position P. When the seconds wheel 20 is rotated further two steps or 6 seconds, the arcuate aperture 40a aligns partially with the detection position P. Thus, the rotational position of the seconds wheel 20 can be confirmed in 6 seconds after the first light blocking area 21d has passed the detection position P. Therefore, when the watch hands should be set within 60 minutes from the related o'clock hour, it is confirmed more quickly in this modification than in the above-mentioned embodiment if the seconds hand 2 is set correctly in the normal rotating operation.
The light blocking area 21e between the arcuate aperture 21c and the circular aperture 21a is provided so as to extend through approximately 48 degrees relative to the circular aperture 21a, or through a net angular extent of approximately 36 degrees which is approximately three times the angle of the circular aperture 21a, as viewed from the center of the seconds wheel 20. Assume that the number of successive non-detection events the detection unit 13 has encountered due to the second blocking area 21e blocking the detection position P is counted by rotating the seconds wheel 20 two steps or 12 degrees at a time. When light passing through the circular aperture 21a is detected by the detection unit 13 after three successive non-detection events are counted, the position of that aperture in the seconds wheel 20 is determined as its reference or 00-second position. Thus, the reference position of the seconds hand 2 is detected more quickly than in the embodiment.
In the above embodiment, its modification and the modifications of the seconds wheel, it is illustrated that the optical detection controlling means stops the detection of the positions of the hands 2, 3 and 4 only for the time period ranging from when the third or last one of the three successive hand position detection errors has occurred to several minutes before the specified next 11 o'clock hour, or more particularly the 55th minute of the specified next 10 o'clock hour. However, the present invention is not limited to this particular case. For example, arrangement may be such that the position detection controlling means stops the detection of the positions of the hands 2, 3 and 4 only for the time period ranging from when the third or last one of the three successive hand position detection errors has occurred to the end of a time zone in the daytime or nighttime where the user has decided not to use of the wristwatch; for example, 10:00 p.m.-06:00 a.m. for which people are presumed to sleep, thereby greatly reducing useless consumption of battery power which would otherwise occur.
While in the embodiment, its modification and the modifications of the seconds wheel 20 the time when the hand positions are detected in the normal hand rotating operation is illustrated as being the 55th minute of every hour on the hour, it is not necessarily required to be so. It may be several minutes, for example between 55 and 59 minutes, before every hour on the hour. While in the embodiment, its modification and the modifications of the seconds wheel 20 the apertures 21a, 28 and 29 provided in the seconds, center and hour wheels 20, 25 and 27 are illustrated as circular, they may be of another form: for example, square, trapezoidal or polygonal.
While in the above embodiment, its modification and the modifications of the seconds wheel the hand-type wristwatches according to the present invention are illustrated, the invention is applicable to other hand-type timepieces such as travelers' clocks or watches, alarm clocks, table or desk clocks, wall clocks, etc.
Various modifications and changes may be made thereunto without departing from the broad spirit and scope of this invention. The above-described embodiments are intended to illustrate the present invention, not to limit the scope of the present invention. The scope of the present invention is shown by the attached claims rather than the embodiments. Various modifications made within the meaning of an equivalent of the claims of the invention and within the claims are to be regarded to be in the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-331355 | Dec 2007 | JP | national |
