Patent Application
20090296533
This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2008-139127, filed May 28, 2008, 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 a hand position control method which detects rotational positions of seconds, center and hour hands.
2. Description of the Related Art
Conventionally, a hand position detecting device which detects the rotational positions of hands of a timepiece is known, as disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2000-162336.
The hand position detecting 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 center and hour hands, respectively, to sweep around the dial. The hand position detecting device also comprises a photosensor including a light emission element and a photo detection element. The photosensor optically detects a first, a second and a third light-passing apertures provided respectively in the seconds, center and hour wheels with the aid of the light emission element and the photo detection element when the seconds, center and hour wheels of the first and second drive systems rotate after pointing to the same direct on on the same axis. The hand position detecting device detects respective rotational positions of the seconds, center and hour wheels based on detected signals from the photosensor and hence rotational positions of the seconds, center and hour hands are determined.
However, the conventional hand detecting device only determines the rotational positions of the seconds, center and hour hands. Thus, when it is determined that these hands rotate around the dial correctly, normal rotations are continued. However, when the hand detecting device is left in darkness for long periods, detection of the hands is repeated many times, thereby consuming a significant amount of battery power.
According to an embodiment of the present invention, a hand position detecting device comprises:
an optical detection unit configured to detect whether or not light passes through light-passing apertures provided in hand wheels having hands;
a hand position detecting unit configured to detect positions of the hands based on passage or non-passage of light detected by the optical detection unit;
a darkness detector configured to detect whether or not the hand position detecting device is in darkness;
a dark state determining unit configured to determine, when the darkness detector detects that the hand position detecting device is in darkness, whether or not the hand position detecting device has been in darkness for a predetermined time period; and
a hand rotation controlling unit configured to, when the dark state determining section determines that the hand position detecting device has been in darkness for the predetermined time period, rotate at least one of the hands to a reference position, stop the one of the hands, and control the hand position detection unit to detect positions of remaining hands at predetermined time intervals.
According to another embodiment of the present invention, a hand position control method used in a hand position detecting device, comprises:
detecting whether or not light passes through light-passing apertures provided in hand wheels having hands;
detecting positions of the hands based on detected passage or non-passage of light;
detecting whether or not the hand position detecting device is in darkness;
determining whether or not the hand position detecting device has been in darkness for a predetermined time period when it is detected that the hand position detecting device is in darkness; and
when it is determined that the hand position detecting device has been in darkness for the predetermined time period, rotating at least one of the hands to a reference position, stopping the one of the hands, and controlling positions of remaining hands to be detected at predetermined time intervals.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the general description given above and the detailed description of the 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
As shown in
The pinion 22d of the rotor 22c in the second driving system 12 rotates 180 degrees or one step per pulse. The intermediate wheel 23 rotates 30 degrees per pulse (per step of the rotor 22c rotation), thereby rotating 360 degrees by 12 pulses (12 steps of the rotor 22c rotation). The third wheel 24 rotates four degrees per pulse (per step of the rotor 22c rotation). The center wheel 25, i.e., the second wheel rotates one degree per pulse (per step of the rotor 22c rotation), thereby rotating 360 degrees by 360 pulses (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 rotates 360 degrees by 4320 pulses (4320 steps of the rotor 22c rotation).
A hand position detecting device of the wristwatch 1 optically detects positions of the first to fourth light-passing apertures 21, 28, 29 and 30 provided in the seconds wheel 20, center wheel 25, hour wheel 27 and intermediate wheel 23 by a detection unit 13 to determine rotational positions of the seconds wheel 20, center wheel 25, hour wheel 27, and intermediate wheel 23. The detection unit 13, as shown in
Therefore, when one of the first to fourth light-passing apertures 21, 28, 29 and 30 of the seconds wheel 20 center wheel 25, hour wheel 27 and intermediate wheel 23 overlap together, the photo detection element 32 detects light from the light emission element 31. Thus, the rotational positions of the seconds wheel 20, center wheel 25, and hour wheel 27 are detected. As shown in
As shown in
As shown in
The second light blocking area 21e is formed between 0-degree position and 60-degree position (50-second position) from the center of the circular aperture 21a (0-degree position) in the clockwise direction. Substantially, the second light blocking area 21e has a width corresponding to 48 degrees that is four times longer than the diameter of the circular aperture 21a (corresponding to 12 degrees), namely, longer than the first light blocking area 21d by the diameter of the circular aperture 21a. The third light blocking area 21f is formed in the almost same size as the circular aperture 21a between the first and second arcuate apertures 21b and 21c and opposed to the circular aperture 21a on the same diameter.
The first light blocking area 21d is diametrically opposed to a part of the second arcuate aperture 21c. The second light blocking area 21e is diametrically opposed to a part of the first arcuate aperture 21b. The third blocking area 21f is diametrically opposed to the circular aperture 21a. Thus, whenever the seconds wheel 20 rotates 180 degrees (half rotation) from the state in which any one of the first to third light blocking areas 21d to 21f blocks a detection position P of the detection unit 13 where the light emission element 31 faces the photo detection element 32, any of the circular and the first and second arcuate apertures 21a, 21b and 21c comes to the detection position P.
The seconds wheel 20 rotates by six degrees (one step) at a time (one second). When the detection unit 13 makes light detection at intervals of two seconds until the seconds wheel 20 rotates 60 steps (360 degrees) in 60 seconds, the pattern shown in
When the rotation of the seconds wheel 20 is between eight seconds (48 degrees) and 28 seconds (168 degrees), the detection unit 13 continuously detects light through the first arcuate aperture 21b. When the seconds wheel 20 rotates 30 seconds (180 degrees), the third light blocking area 21f blocks the detection position P, and the detection unit 13 cannot detect light. From 32seconds (192 degrees) to 50 seconds (300 degrees), the detection unit 13 continuously detects light through the second arcuate aperture 21c. From 52 seconds (312 degrees) to 58 seconds (348 degrees), the second light blocking area 21e blocks the detection position P, and the detection unit 13 fails in light detection successively four times.
As shown by a solid line in
As shown in
As shown in
In the second driving system 12, the intermediate wheel 23, center wheel 25 and hour wheel 27 respectively rotate 30 degrees, one degree, and 1/12 degrees per step (half rotation of the rotor 22c). Thus, as shown in
The seconds wheel 20 of the first driving system 11 rotates six degrees per step (half rotation of the rotor 17c). Every time the seconds wheel 20 rotates 60 steps (60 seconds), the circular aperture 21a of the first light-passing aperture 21 comes to the detection position P. Therefore, as shown in
Hereinafter, description will be made on preconditions for detecting the rotational positions of the seconds, center and hour hands 2, 3 and 4 by the detection unit 13. When the circular aperture 21a, the second light-passing aperture 28 and one of the third light-passing apertures 29 are aligned together at twelve o'clock position (in the uppermost position of the wheels 20, 25 and 27 in
When the light-passing apertures 21a and 28 to 30 are aligned together at the detection position P, the photo detection element 32 receives light from the light emission element 31. When any of the light-passing apertures 21a and 28 to 30 is offset or away from the detection position P, the light from the light emission element 31 is blocked. Therefore, the photo detection element 32 cannot detect the light.
When rotations of the rotors 17c and 22c of the first and second stepping motors 17 and 22 are reversed 180 degrees, the first and second stepping motors 17 and 22 rotate the hands by one step. If pulses of opposite polarities are output at every step, the rotors 17c and 22c rotate. Thus, even when pulses of the same polarity are applied successively to the stepping motors 17 and 22, the rotors 17c and 22c do not rotate and remain stopped.
For example, in the case where the seconds hand 2 is shifted by one step due to an external factor such as a shock, even when a pulse to rotate the seconds hand 2 is output, the seconds hand 2 does not rotate at that time point, and then, the seconds hand 2 rotates when the subsequent pulse is output. The first stepping motor 17 of the first driving system 11 requires execution of position detection for the seconds wheel 20 at every two steps. Unless the seconds wheel 20 rotates two steps, the circular aperture 21a is not completely away from the detection position P due to a relationship between the size of the circular aperture 21a and a moving quantity per step of the seconds wheel 20. Thus, execution of the position detection at every two steps (every two seconds) is effective. With the second driving system 12, it is effective that the detection is executed at every step.
Then, referring to
Hereinafter, description on the center, hour and intermediate wheels 25, 27 and 23 of the second driving system 12 will be omitted for the sake of simplicity.
The reference position of the seconds wheel 20 can be obtained by detecting the reference position (00-second position) of the seconds wheel 20 shown in
The seconds wheel 20 rotates by two steps in the clockwise direction from the state of
Then, as shown in
When the seconds wheel 20 rotates further two steps and the rotational angle thereof comes to 180 degree as shown
Until the rotational angle of the seconds wheel 20 becomes 300 degrees as shown in
Until the rotational angle of the seconds wheel 20 becomes 348 degrees, a part of the second light blocking area 21e covers the detection position P as shown in
As described above, in the state of
The detection unit 13 fails in light detection in the states of
That is, the detection unit 13 makes the position detection each time the seconds wheel 20 rotates two steps (two seconds). A position, where the detection unit 13 succeeds in light detection after four times of successive detection failure, is determined to be the reference position (00-second position). If detection failure starting from the state of
Next, referring to
Hereinafter, description of the seconds wheel 20 in the first driving system 11 will be omitted for the sake of simplicity.
The reference position (0-o'clock 00-minute position) of the center and hour wheels 25 and 27 can be obtained by detecting the reference position P shown in
When the center wheel 25 rotates one step (one degree) from the state shown in
Then, when the center wheel 25 rotates six steps (six degrees) in total, the rotation angle of the intermediate wheel 23 becomes 180 degrees and the fourth light-passing aperture 30 is moved 180 degrees away from the detection position P as shown in
Then, when the center wheel 25 rotates 12 steps (12 degrees) in total, the rotation angle of the intermediate wheel 23 becomes 360 degrees and the fourth light-passing aperture 30 comes to the detection position P, as shown in
When the center wheel 25 is rotates 360 steps (one rotation) in total, the second and fourth light-passing apertures 28 and 30 in the center and intermediate wheel 25 and 23 are aligned together at the detection position P, as shown in
Then, when the center wheel 25 rotates further one hour (11 hours in total), the second and forth light-passing apertures 28 and 30 are aligned together at the detection position P, as shown in
When the center wheel 25 rotates further one hour (12 hours in total), the second and fourth apertures 28 and 30 are aligned at the detection position P, as shown in
As described above, since the rotational angle of the center wheel 25 per step is quite small, i.e., one degree, one step of the rotation of the center wheel 25 is not enough to move the second light-passing aperture 28 completely away from the detection position P. Therefore, the reference position of the center wheel 25 may not be detected accurately. However, the intermediate wheel 23 rotates 30 degrees per step and this rotational angle per step is large enough to cover the detection position P even if the rotational angle of the center wheel 25 per step is small.
As shown in
Each time the center wheel rotates 360 degrees (one rotation) in 360 steps, the second and fourth light-passing apertures 28 and 30 and any of the third light-passing apertures 29 (aside from the fourth light blocking area 29a at 11-o'clock position) come to the detection point P, and the detection unit 13 can detect light passing through the apertures. That is, the detection unit 13 can detect light at a “00-minute position” or the reference position (0-degree position), to which the center wheel 25 returns every time the center wheel 25 rotates 360 degrees (360 steps) regardless of the rotational position of the hour wheel 27 (except 11-o'clock position).
After the reference position (0-degree position) of the center wheel 25 is detected, the center wheel 25 rotates 360 steps (one rotation) at a time, and the hour wheel 27 rotates 30 degrees at a time. Thus, light detection by the detection unit 13 is not required to be executed at each step of the rotation of the center wheel 25. The detection unit 13 may perform light detection only when the center wheel 25 rotates 360 degrees to detect the rotational position of the hour wheel 27. In the case where the center wheel 25 rotates 360 steps at a time from the state of
When the center wheel 25 rotates further 360 degrees from the “11-o'clock 00-minute” position, the reference circular aperture which is one of the third light-passing apertures 29 in the hour wheel 27 comes to the detection position P and the detection unit 13 can detect light passing through the reference aperture. This position of the center and hour wheels 25 and 27 is determined as the reference position, i.e., “0-o'clock 00-minute” position. Thus, the detection unit 13 performs light detection each time the center wheel 25 rotates 360 degrees (one rotation) after the state in which light detection by the detection unit 13 is possible. After the detection unit 13 fails in detecting light (state in
Referring to
The three-hand position detection operation comprises a combination of the operation to detect the position of the seconds wheel 20 and the operation to detect the position of the center and hour wheels 25 and 27. The three-hand position detection operation can he applied to the following three cases wherein the detecting condition is not satisfied. In the first case, the first light passing apertures 21 in the seconds wheel 20 are out of the detection position P. In the second case, the second light-passing aperture 28 in the center wheel 25 and/or any of the third light-passing apertures 29 in the hour wheel 27 are out of the detection position P. In the third case, the first light-passing apertures 21 are out of the detection position P and the second light-passing aperture 28 and/or the third light-passing apertures 29 are out of the detection position P.
First, referring to
It is assumed that the state of the seconds wheel 20 is unknown and that the center wheel 25 and the hour wheel 27 are set at the reference position (0-o'clock 00-minute position). The basic operation to detect the reference position of the seconds hand 20 is performed firstly. That is, as described above, the second wheel 20 rotates two steps, and the detection unit 13 performs light detection at every two steps of the rotation.
When the seconds wheel 20 rotates two steps and the state shown in
When the seconds wheel 20 rotates further two steps as shown in
Subsequently, the detection unit 13 tries to detect light every time the seconds wheel 20 rotates two steps. As shown
Two steps later, the detection unit 13 detects light and it is determined that the seconds wheel 20 is located at the reference position (00-second position). As shown in
Then, referring to
Even in the case where one of the first light-passing apertures 21 in the seconds wheel 20 is located at the detection position P, when the light-passing apertures in the center and hour wheels 25 and 27 are out of the detection position P, the detection unit 13 fails in detecting light. Therefore, firstly, the basic operation to detect the reference position of the seconds wheel 20 is performed.
The detection unit 13 performs light detection every time the seconds wheel 20 rotates two steps. When the detection result changes from the state shown in
Basically, the reference position of the seconds wheel 20 is detected when the light detection is successful two steps after four times of continuous detection failure, as described above. However, as shown in
As a result, the detection unit 13 fails 1n light detection successively five times. The five times of continuous detection failure is not assumed in the operation to detect the reference position of the seconds wheel 20. Accordingly, it can be recognized that the second light-passing aperture 28 in the center wheel 25 is away from the detection position P and/or the third light-passing apertures 29 in the hour wheel 27 are away from the detection position P. In this state, it is uncertain whether or not one of the first light-passing apertures 21 is aligned with the detection position P.
However, it can be recognized that the second light-passing aperture 28 is away from the detection position P and/or the third light-passing apertures 29 are away from the detection position P; accordingly the basic operation to detect the reference position of the center and hour wheels 25 and 27 is performed. The detection unit 13 performs light detection every time the center wheel 25 rotates one step. When the state of the center and hour wheels 25 and 27 changes from that of
As a result, it can he understood that the center wheel 25 is set at the reference position (00-minute position). However, positions at which the seconds and hour wheels 20 and 27 are set are unknown. As the detection unit 13 can detect light passing through the apertures, the basic operation to detect the reference position of the seconds wheel 20 is performed. The seconds wheel 20 is moved to the reference position (00-minute position) as shown in
Then, the center wheel 25 rotates 360 degrees (one rotation) at a time. Every time the center wheel 25 rotates 360 degrees, the third light-passing apertures 29 in the hour wheel 27 come to the detection position P in turn, and the detection unit 13 detects light passing through the apertures 29. 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 hour wheel 27 is set at the reference position (0-o'clock position). All of the seconds, center and hour wheels 20, 25 and 27 are disposed at the reference position (0-o'clock 00-minute 00-second position).
Next, referring to
In this case, rotational positions of the seconds, center and hour wheels 20, 25 and 27 are unknown. Thus, the basic operation to detect the reference position of the seconds wheel 20 is firstly performed. That is, starting from the state shown in
Therefore, the basic operation to detect the reference position of the seconds wheel 20 is further performed. Basically, to detect the reference position of the seconds wheel 20, the seconds wheel 20 rotates two steps and the detection unit 13 performs light detection at every two steps, and when the light detection is successful two steps after four times of continuous detection failure, the reference position of the seconds wheel 20 is detected, as described above. As shown in
Here, the second light-passing aperture 28 in the seconds wheel 25 is considered being away from the detection position P. The basic operation to detect the reference position of the center and hour wheels 25 and 27 is performed. The center wheel 25 rotates one step at a time and the detection unit 13 performs light detection at every step. When the detection unit 13 fails in detecting light in the case where the center wheel 25 rotates 360 degrees from the state shown in
In the case where the first light-passing apertures 21 in the seconds wheel 20 are away from the detection position P, when the seconds wheel 20 rotates 180 degrees (half rotation), one of the first light-passing apertures 21 surely comes to the detection position P as shown in
Referring to
The basic hand-position confirming operation includes confirming whether the seconds hand 2 is correctly located every hour on the hour excluding 11 o'clock and 23 o'clock and it is required to confirm deviation of the seconds hand 2 within 10 seconds. This is because, when ten seconds has elapsed from the hour, the center wheel 25 rotates one step (one degree) by the second stepping motor 22 of the second driving system 12, and as a result, the intermediate wheel 23 rotates 30 degrees to block the detection position P of the detection unit 13.
In
When the seconds wheel 20 rotates further one step (two steps or 12 degrees in total) and comes to a position of 2 seconds (2-second position) shown in
The seconds wheel 20 is further rotated by one step at a time and the detection unit 13 tries to detect light at every two steps. The first light blocking area 21d of the seconds wheel 20 continuously covers the detection position P of the detection unit 13 at a 4-second position shown in
When the seconds wheel 20 rotates further two steps, a part of the first arcuate aperture 21b in the seconds wheel 20 covers the detection position P at an 8-second position shown in
Thereafter, when the seconds wheel 20 rotates further two steps and ten seconds has elapsed, a part of the first arcuate aperture 21b in the seconds wheel 20 covers the detection position P through which the light from the light emission element 31 can pass as shown in
Next, referring to
The circuit configuration comprises a CPU 35 which controls the whole circuit, a read only memory (ROM) 36 which stores predetermined programs, a random access memory (RAM) 37 which stores data to be processed, an oscillator 38 which generates a pulse signal to operate the CPU 35, a frequency divider 39 which converts a frequency of the pulse occurred by the oscillator 38 to an appropriate frequency to operate the CPU 35, a watch movement 8 which rotates the seconds, center and hour hands 2, 3 and 4 around the dial, and the detection unit 13 which comprises the light emission element 31 and the photo detection element 32 which receives light from the light emission element 31.
The circuit configuration further comprises a power supply 40 which includes a battery to supply power, an antenna 41 which receives the standard radio waves, a wave detector 42 which detects the received standard radio waves, an illuminator 43 which illuminates time indications, a driver 44 which drives the illuminator 43, a speaker 45 which emanates sound, a buzzer circuit 46 which drives the speaker 45, the solar panel 9 which determines whether or not the wristwatch 1 is in darkness, and push-button switches SWs.
Next, referring to
The basic seconds hand position detecting process detects the reference position (00-second position) of the seconds wheel 20 where the circular aperture 21a of the first light-passing apertures 21 in the seconds wheel 20 is aligned with the detection position P, as shown in
When the seconds hand position detecting process is started, the number of times of detection failure that is previously counted is cleared and a non-detection flag is to “0” (step S1). The seconds wheel 20 rotates two steps (12 degrees) (step S2). The light emission element 31 of the detection unit 13 is caused to emit light (step S3) and it is determined whether or not the light from the light emission element 31 is received by the photo detection element 32, namely, whether the detection unit 13 succeeds or fails in detecting the light (step S4).
When one of the circular aperture 21a, first arcuate aperture 21b and second arcuate aperture 21c in the seconds wheel 20 covers the detection position P, the photo detection element 32 receives the light from the light emission element 31 through the aperture and it is determined that the detection unit 13 succeeds in light detection. Then, the flow returns to step S1 and the above processing of steps S1 to S4 is repeated until one of the light blocking areas 21d to 21f in the seconds wheel 20 blocks or covers the detection position P.
As the seconds wheel 20 rotates by two steps at a time, when the apertures 21a, 21b and 21c in the seconds wheel 20 are offset from the detection position P and one of the light blocking areas 21d to 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. That is, the detection unit 13 fails in detecting light, and the non-detection flag is set to “1” and the number of times of detection failure is incremented by one (step S5). Then, it is determined whether or not the detection unit 13 fails in detecting light successively four times (step S6).
As described above, when the detection unit 13 detects light after four times of detection failure as shown in
In the state shown in
Thereafter, the seconds wheel 20 rotates further two steps (step S7), and the light emission element 31 emits light (step S8). It is determined whether or not the light from the light emission element 31 is received by the photo detection element 32 (step S9). If yes, it is determined that the circular aperture 21a in the seconds wheel 20 is located at the detection position P and the seconds wheel 20 is positioned at the reference position (00-second position). Then, a hand position correction is performed and the positions of the seconds, center and hour hands 2, 3, and 4 are returned to the current time (step S10). Thereafter, operation of the wristwatch 1 is returned to its normal hand rotating operation, and the process is terminated.
In step S9, it is assumed that the second and fourth light-passing apertures 28 and 30 and relevant one of the third light-passing apertures 29 are aligned together and stopped at the detection position P. Thus, the detection unit 13 necessarily can detect light. However, if any of the apertures 28, 29 and 30 is offset or away from the detection position P, the detection unit 13 detects no light and a center hand position detecting process (see
Referring to
The center hand position detecting process detects the reference position (00-minute position) of the center wheel 25 where the second and fourth light-passing apertures 28 and 30 in the center and intermediate wheels 25 and 23 are aligned together at the detection position 2, as shown in
When the center hand position detecting process is started, the center wheel 25 rotates clockwise one step or one degree (step S12), the light emission element 31 emits light (step S13), and it is determined whether or not the light from the light emission element 31 is received by the photo detection element 32 (step S14). If no, processing of steps S12 to S14 is repeated until the seconds wheel 25 rotates 360 degrees (one rotation; one hour) (step S15).
Even after the center wheel 25 rotates 360 degrees (one hour), when the detection unit 13 fails in detecting light, it is determined that the first light-passing apertures 21 in the seconds wheel 20 are away from the detection position P. Thus, the seconds wheel 20 rotates 30 steps (180 degrees), to locate one of the first light-passing apertures 21 at the detection position P (step S16). Then, the processing of steps S12 to S15 is repeated until the seconds wheel 25 rotates further 360 degrees.
When the detection unit 13 succeeds in detecting light in step S14, it is determined that the center wheel 25 is set at the reference position (00-minute position). However, it is necessary to confirm whether this determination is correct or not. For example, when the intermediate wheel 23 rotates 360 degrees and returned to the reference position and the center wheel 25 rotates 12 steps to move the second light-passing aperture 28 away 12 degrees from the detection position P as shown in
The center wheel 25 is returned 20 steps counterclockwise from the rotational position where the light passing through the apertures is detected by the detection unit 13 in step S14 (step S17), that is, the center wheel 25 is returned more than 14 degrees for the second light-passing aperture 28 to be moved almost completely away from the detection position P. Then, the center wheel 25 fast rotates six steps in the clockwise direction (step S18). Therefore, any possible backlash between the center and intermediate wheels 25 and 23 is eliminated, and the center wheel 25 is reversed by 14 steps from a position where the successful light detection is brought about.
It is assumed that, when the center wheel 25 is returned 14 steps counterclockwise from the reference position, the second light-passing aperture 28 in the center wheel 25 is completely away from the detection position P of the detection unit 13. The center wheel 25 again rotates clockwise one step from the returned position (step S19). The light emission element 31 of the detection unit 13 emits light (step S20). Then, it is determined whether or not the light from the Light emission element 31 is received by the photo detection element 32, namely, whether the detection unit 13 succeeds or fails in light detection (step S21).
When the detection unit 13 detects no light, the processing of steps S19 to S21 is repeated until the center wheel 25 rotates 14 steps (step S22). It is naturally assumed that the detection unit 13 detects light in step S21 within 14 steps. However, if the detection unit fails in detecting light over 14 steps, a hand position detection error is reported by means of a stop position of the seconds hand 2 or buzzer sound (step S23). When the detection unit 13 detects light in step S21, the position of the center wheel 25 is determined to be the reference position (00-minute position) (step S24). Then, this process is terminated.
Next, referring to
The hour hand position detecting process involves detecting the reference position of the hour wheel 27 (0-o'clock position). As shown in
When the hour hand position detecting process is started, the center wheel 25 which is set at the reference position (i.e., the second light-passing aperture 28 is positioned at the detection position P) rotates 360 degrees and the hour wheel 27 rotates 30 degrees (step S25). The light emission element 31 of the detection unit 13 emits light (step S26). It is determined whether or not the light from the light emission element 31 is detected by the photo detection element 32 and it is determined whether or not one of the third light-passing apertures 29 in the hour wheel 27 comes to the detection position P to allow the detection unit 13 detecting the light (step S27).
The hour wheel 27 includes the third light-passing apertures 29, which includes eleven circular apertures which are spaced at angular intervals of 30 degrees, and the fourth light blocking area 29a at the 11-o'clock position. When the center wheel 25 rotates 360 degrees and the hour wheel 27 rotates 30 degrees, the third light-passing apertures 29, in turn, come to the detection position P except the fourth light blocking area 29a as shown in
As shown in
In step S30, the reference circular aperture of the third light-passing apertures 29 in the hour wheel 27 is naturally set at the detection position P as shown in
Referring to
The three-hand position detecting process is executed when the positions of the seconds, center and hour hands 2, 3 and 4 are unknown. The three-hand position detecting process is a combination of the above-described seconds hand position detecting process and hour and center hand position detecting process.
At the time of starting the three-hand position detecting process, because none of the positions of the seconds, center and hour hands 2, 3 and 4 is known, the seconds hand position detecting process of
At this time, none of the rotational positions of 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 succeeds in light detection, the flow returns to step S31 and the processing of steps S31 to S34 is repeated until one of the first to third light blocking areas 21d to 21f of the seconds wheel 20 covers the detection position P.
When the detection unit 13 succeeds in detecting light in step S34, one of the light-passing aperture 21a, the second light-passing aperture 28, one of the light-passing apertures 29 and light-passing aperture 30 are happens to be aligned together at the detection position P. It can be considered that the center wheel 25 is set at the reference position (00-minute position); however, the rotational positions of the seconds and hour wheels 20 and 27 are unknown. First, the rotational position of the seconds wheel 20 will be detected; therefore, the processing of steps S31 to S34 is repeated until one of the first to third light blocking areas 21d to 21f in the seconds wheel 20 covers the detection position P and disables the detection unit 13 from detecting light.
When one of the first to third light blocking areas 21d to 21f in the seconds wheel 20 comes to the detection position P and the detection unit 13 fails in detecting light in step S34, counting the number of times of detection failure is started and the non-detection flag bit is set to “1” (step S35). Then, it is determined whether or not the detection unit 13 fails in detecting light successively four times (step 36).
The processing of steps S32 to S36 is repeated until the second light blocking area 21e in the seconds wheel 20 covers the detection position P and the number of times of detection failure in the detection unit 13 arrives at four times. When the detection unit 13 fails in detecting light successively four times, the seconds wheel 20 is rotated two steps (step S37), and the light emission element 31 is caused to emit light (step S38). Then, it is determined whether or not the light from the light emission element 31 is received by the photo detection element 32, that is, whether the detection unit 13 succeeds or fails in light detection (step S39).
When the detection unit 13 succeeds in light detection in step S39, it is determined that the center wheel 25 is located at the reference position (00-minute position) and the second light-passing aperture 28, one of the third light-passing apertures 29, and the circular aperture 21a are aligned together at the detection position P. Therefore, it is determined that the seconds wheel 20 and the center wheel 25 are set at the reference position (00-second 00-minute position), and then the flow goes to step S80 in the hour hand position detecting process to be described later.
When the detection unit 13 detects no light in step S39, the number of times of detection failure becomes five even though the circular aperture 21a in the seconds wheel 20 is positioned at the detection position P as shown in
As shown in
When the detection unit 13 succeeds in detecting light in step S43, it is understood that one of the first light-passing apertures 21, the second and fourth light-passing apertures 28 and 30, and one of the third light-passing apertures 29 are aligned together at the detection position P. It is also understood that, before step S41, the apertures in the center and hour wheels 25 and 27 have been offset from the detection position P. Thus, it is determined that the center wheel 25 is set at the reference position (00-minute position), and the flow goes to step S71 of the center hand position detecting process to confirm whether this determination is correct or not.
However, even though the center wheel 25 rotates 360 degrees, when the detection unit 13 detects no light in step S43, it is considered that the first light-passing apertures 21 are out of the detection position P as shown in
When the detection unit 13 succeeds in detecting light in step S47, it is understood that one of the first light-passing apertures 21, the second and fourth light-passing apertures 28 and 30, and one of the third light-passing apertures 29 are aligned together at the detection position P, and that, before step S45, the first, light-passing apertures 21 in the seconds wheel 20 have been away from the detection position P. It is determined that the center wheel 25 is set at the reference position (00-minute position), and then, the flow passes to step S71 of the center hand position confirming process.
After the seconds wheel 20 rotates 30 steps (180 degrees) in step S45, when the detection unit 13 detects no light in step S47, it is determined, as shown in
The light emission element 31 is caused to emit light (step S49), and it is determined whether or not the light from the light emission element 31 is received by the photo detection element 32, and hence whether or not the detection unit 13 succeeds in detecting light (step S50). If not, the center wheel 25 is rotated one step (step S48), and it is determined whether or not the center wheel 25 rotates 360 degrees (step S51). If not, the processing of steps S48 to S51 is repeated until the center wheel 25 rotates 360 degrees (one rotation).
When the detection unit 13 detects light in step S50, it is recognized that one of the first light-passing apertures 21 in the seconds wheel 20, the second and fourth light-passing apertures 28 and 30 in the center and intermediate wheels 25 and 23, and one of the third light-passing apertures 29 in the hour wheel 27 are aligned together at the detection position P. Also it is seen that, before step S50, the second light-passing aperture 28 in the center wheel 25 has been offset from the detection position P. It is determined that the center wheel 25 is set at the reference position (00-minute position). Then, the flow goes to step S71 of the center hand position confirming process.
After the center wheel 25 rotates 360 degrees, when the detection unit 13 detects no light in step S50, it is determined that the third light-passing apertures 29 in the hour wheel 27 are away from the detection position P and that the fourth light blocking area 29a in the hour wheel 27 covers the detection position P even though one of the first light-passing apertures 21, and the second and fourth light-passing apertures 28 and 30 are aligned together at the detection position P, as shown in
It cannot be known whether any of the first light-passing apertures 21 in the second wheel 20 is located at the detection position P or not. Thus, the seconds wheel 20 rotates 30 steps (180 degrees) (step S52), and the light emission element 31 is caused to emit light (step S53). It is determined whether or not the light from the light emission element 31 is received by the photo detection element 32, that is, whether or not the detection unit 13 succeeds in detecting light (step S54).
When the detection unit 13 succeeds in light detection, one of the first light-passing apertures 21, the second and fourth light-passing aperture 28 and 30, and one of the third light-passing apertures 29 are aligned together at the detection position P. The fourth light blocking area 29a of the hour wheel 27 does not cover the detection position P. It can be seen that, before step S52, the first light-passing apertures 21 in the seconds wheel 20 have been offset from the detection position P. It is determined that the center wheel 25 is set at the reference position (00-minute position), and then, the flow goes to step S71 of the center hand position detecting process.
When the detection unit 13 detects no light in step S54, it is determined that the fourth light blocking are 29a of the hour wheel 27 covers the detection position P as shown in
When the detection unit 13 succeeds in detecting light in step S57, one of the first light-passing apertures 21, the second and fourth light-passing apertures 28 and 30, and one of the third light-passing apertures 29 are aligned together at the detection position P. In addition, the light blocking area 29a of the hour wheel 27 does not block the detection position P. It is determined that, before step S55, the second light-passing aperture 28 in the center wheel 25 has been away from the detection position P. It is determined that the center wheel 25 is now set at the reference position (00-minute position). Then, the flow goes to step S71 of the center hand position confirming process.
After the center wheel 25 rotates 360 degrees (step S58), when the detection unit 13 detects no light in step S57, it is assumed that the detection position P is blocked by the fourth light blocking area 29a in the hour wheel 27, and that the hour wheel 27 is set at the 11-o'clock position. In order to confirm whether this assumption is correct or not, the seconds wheel 20 rotates 30 steps (180 degrees) (step S59) and the light emission element 31 is caused to emit light (step S60). It is determined whether or not the light from the light emission element 31 is received by the photo detection element 32, that is, whether the detection unit 13 succeeds or fails in light detection (step S61).
When the detection unit 13 succeeds in detecting light, one of the first light-passing apertures 21 in the seconds wheel 20, the second and fourth light-passing apertures 28 and 30 in the center and intermediate wheels 25 and 23, and one of the third light-passing apertures 29 in the hour wheel 27 are aligned together at the detection position P. Thus, it is determined, before step S59, that the hour wheel 27 has not been set at the 11-o'clock position and the first light-passing apertures 21 have been away from the detection position P. It is determined that the center wheel 25 is set at the reference position (00-minute position). Then the flow goes to step S71 of the center hand position confirming process.
When the detection unit 13 detects no light in step S61, the fourth light blocking area 29a in the hour wheel 27 blocks the detection position P. The center wheel 25 rotates one step (step S62), and the light emission element 31 is caused to emit light (step S63). It is determined whether or not the light from the light emission element 31 is received by the photo detection element 32, that is, whether or not the detection unit 13 succeeds in light detection (step S64).
When the detection unit 13 detects no light in step S64, the center wheel 25 is rotated one step and it is determined whether or not the center wheel 25 rotates 360 degrees in total (step S65). If not, the processing of steps S62 to S64 is repeated until the center wheel 25 rotates 360 degrees. After the processing of steps S62 to S64 is repeated, when the detection unit 13 detects no light in step S64, a hand position detection error is reported by means of a stop position of the seconds hand 2 or buzzer sound (step S66). When the detection unit. 13 detects light in step S64, it is determined that the hour wheel 27 is positioned at the reference position (0-o'clock position) and the center wheel 25 is positioned at the reference position (00-minute position). Then, the flow goes to the step S71 for the center hand position confirming process.
As shown in
That is, the center wheel 25 is returned 14 steps which are more than 12 degrees that is necessary for the second-light passing 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 (step S73), and the light emission element 31 is caused to emit light (step S74). It is determined whether or not the light from the light emission element 31 is received by the photo detection element 32, that is, whether or not the detection unit 13 succeeds in light (step S75).
When the detection unit 13 detects no light in step S75, the processing of steps S73 to S75 is repeated until the center wheel 25 rotates 14 steps (step S76). The detection unit 13 is assumed necessarily to detect light in step S75. However, if the detection unit 13 fails in light detection, a hand position detection error is reported by means of a stop position of the seconds hand 2 or buzzer sound (step S77). When the detection unit 13 detects light in step S75, the position at the time of the light detection is determined to be the reference position (00-minute position) of the center wheel 25 (step S78).
Since it is unclear whether seconds wheel 20 is set at the reference position (00-second position) or not, the flow returns to step S31 of the seconds hand position detecting process to perform the processing of steps S31 to S39. The seconds wheel 20 rotates to the reference position (0-minute 00-second position). Then, the flow goes to step S80 of the hour hand position detecting process shown in
When the detection unit 13 detects light every time the hour wheel 27 rotates 30 degrees, it is determined that the third light-passing apertures 29 in the hour wheel 27 successively comes to the detection position P and the hour wheel 27 is successively positioned at exact hour positions. Thus, the flow returns to step S80 and the processing of steps S80 to S82 is repeated until the fourth light blocking area 29a at the 11-o'clock position in the hour wheel 27 covers the detection position P. When the detection unit 13 detects no light, it is determined that the fourth light blocking area 29a in the hour wheel 27 covers the detection position P and that the hour wheel 27 is set at the 11-o'clock position.
In order to confirm whether this determination is correct or not, the center wheel 25 is again rotated 360 degrees and the hour wheel 27 is rotated 30 degrees (step S33). Then, the light emission clement 31 emits light (step S84). It is then determined whether or not the light from the light emission element 31 is received by the photo detection element 32, that is, whether or not the detection unit 13 succeeds in light detection (step S85).
When the detection unit 13 detects light, the seconds, center and hour wheel 20, 25 and 27 are set at the reference position (0-o'clock 00-minute 00-second position). The seconds, center and hour hands 2, 3 and 4 are set to indicate the exact current time (step S86) and then the normal driving operation is started. Thus, this process is terminated. It is assumed that the detection unit 13 necessarily detects light in step S85; however, when the detection unit 13 fails in light detection, a hand position detection error is reported by means of a stop position of the seconds hand 2 or buzzer sound (step S87).
Then, referring to
In the hand position confirming process, the detection unit 13 makes light detection at every 55 minutes past the hour, excluding ten fifty-five a.m. and ten fifty-five p.m.
The hand position confirming process may be executed at every hour on the hour; however, execution of the process may coincide with generation of a time/alarm signal or other various operations to be performed. Thus, it is preferable that the hand position confirming process is executed several minutes before the hour. The hour wheel 27 rotates one degree per 12 minutes; therefore, even when the execution of the process is made 10 minutes or so offset from the hour, one of the third light-passing apertures 29 is not completely moved away from the detection position P to allow the detection unit to detect light.
When the detection unit 13 detects light in the process at every 55 minutes past the hour, the hour hand 4 is regarded as being set correctly. Then, it is confirmed whether or not the seconds and center hands 2 and 3 are set correctly, and a difference in the position of the center hand 3 less than 60 minutes can be confirmed. When 10 seconds elapses from the start of the process, the center wheel 25 is rotated one step and thus the intermediate wheel 23 is rotated 30 degrees, thereby blocking the detection position P. It is necessary to confirm the difference in the position of the seconds hand 2 in ten seconds from the start of the process.
The hand position confirming process starts at every hour 55 minutes past the hour excluding 11 o'clock and 22 o'clock. The light emission element 31 is caused to emit light (step S90). Then, it is determined whether or not the light from the light emission element 31 is received by the photo detection element 32, that is, whether or not the detection unit 13 succeeds in light detection (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 flow goes to the above-described three-hand position detecting process.
When the detection unit 13 succeeds in detecting light, it is determined that one of the first light-passing apertures 21 in the seconds wheel 20 is positioned at the detection position P. The number of times of detection failure counted previously is cleared and the non-detection flag is set to “0” (step S92). Then, the seconds wheel 20 is normally rotated one step (six degrees) and the seconds hand 2 is normally rotates around the dial (step S93). It is determined whether or not the seconds wheel 20 rotates two steps (12 degrees) in total (step S94). Even when the seconds wheel 20 rotates only one step or six degrees, the circular aperture 21a in the seconds wheel 20 is not completely moved away from the detection position P; therefore, the detection unit 13 makes light detection each time the seconds wheel 20 rotates two steps.
When it is determined that the seconds wheel 20 does not rotates two steps in step S94, the seconds hand is normally rotated by one step (six degrees) at a time. Every time the seconds wheel 20 rotates two steps, it is determined whether or not the seconds hand 2 is set at any of positions of 2, 4, 6 and 8 seconds (step S95). Since the first stepping motor 17 may not operate correctly due to external factors such as external magnetic field, the seconds hand 2 may not indicate any of the positions of 2, 4, 6 and 8 seconds. In such a case, a hand position detection error is reported by means of a stop position of the seconds hand 2 and/or buzzer sound (step S96).
When it is determined in step S95 that the seconds hand 2 indicates one of the positions of 2, 4, 6 and 8 seconds without being influenced by the external factors, the light emission element 31 of the detection 13 emits light (step S97). It is determined whether or not the light from the light emission element 31 is received by the photo detection element 32, that is, whether or not detection unit 13 succeeds in light detection (step S98). When the detection unit 13 detects light, one of the first light-passing apertures 21, i.e., the circular aperture 21a, first arcuate aperture 21b and second arcuate aperture 21c in the seconds wheel 20 is located at the detection position P. Hence it is determined that, before step S93, the seconds wheel 20 has not been set exactly. The flow goes to the three-hand position detecting process.
When the detection unit 13 detects no light in step S96, it is determined that one of the first to third light blocking areas 21d to 21f of the seconds wheel 20 covers the detection position P as shown in
When it is determined that three times of detection failure are successively occurred six seconds after 55 minutes past the hour as shown by a change from
When the seconds wheel 20 rotates two steps, the light emission element 31 is caused to emit light (step S103). It is determined whether or not the light from the light emission element 31 is received by the photo detection element 32, that is, whether or not the detection unit 13 succeeds in light detection at eight seconds after 55 minutes past the hour (step S104). When the detection unit 13 detects no light, it is determined that the second light blocking area 21e covers the detection position P and that the seconds wheel 20 is not set at the correct rotational position. Thus, the flow goes to the three-hand position detecting process. When the detection unit 13 detects light in step S104, a part of the first arcuate aperture 21b in the seconds wheel 20 covers the detection position P as shown in
Next, referring to
According to the hard position confirming process, the flow goes to the three-hand position detecting process from steps S91, S98 and S104. When a hand position detection error is occurred in the hand position confirming process or in the three-hand position detecting process, hand position detection is stopped until ten fifty-five a.m. or ten fifty-five p.m.
When the error processing is started, the hand position confirming process of steps S90 to S104 is performed (step S110). Then, the flow goes to the three-hand position detection process from step S91, S98 or S104 and it is determined whether or not a hand position detection error is occurred in the three-hand position detection process or the hand position confirming process (step S111). If not, an error counter (not shown) is cleared to be zero (step S112) and then the hand position confirming process is normally performed at every 5 minutes before the hour (step S113).
When it is determined in step S111 that a hand position detection error is occurred, a value of the error counter is incremented (step S114). It is determined whether or not the number of successive errors counted by the error counter comes to a predetermined number (in this embodiment, successive three errors) (step S115). If not, the flow returns to step S110 and the above processing is repeated until three hand position detection errors are successively occurred.
When it is determined in step S115 that the hand position detection errors are occurred successively three times, the contents of the errors are stored in the RAM 37 and then the hand position confirming process involving steps S90 to S104 of
Next, referring to
When three of push-button switches SWs (see
Error No. 0 indicates that the hands are detected at their correct positions. The seconds hand 2 is stopped at a 55 seconds position.
Error No. 1 indicates that the center hand 3 is erroneously determined as being at a correct position 12 steps before its proper position in the center hand position confirming process of
Error No. 2 indicates that the steps S31 to S36 are performed in a section E2 of
Error No. 3 indicates that each time the center hand a rotates 360 degrees, the steps S80 to S85 are performed in a section E3 of
Error No. 4 occurs in a section E6 of
Error No. 5 indicates that the steps S93 to S98 are performed in a section E7 of
Error No. 6 occurs when light is detected successively 11 times and then not in a next trial in the steps S52 to S66 in a period E5 of the three-hand position detection process of
Error No. 7 occurs when no light is detected in the three-hand position detection process of
Error No. 8 occurs after at least one light detection is performed successfully in the three-hand position detecting process of
Error No. D 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. The seconds hand 2 is stopped at a 39 seconds position.
Error No. E 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. The seconds hangs 2 is stopped at a 42 seconds position. The above-mentioned errors Nos. D and E are errors due to the circuit system.
Next, referring to
When the hand controlling process is started, it is determined whether or not the solar panel 9 is detecting external light and generating electricity to determine whether the wristwatch 1 is in darkness or not (step S120). When the solar panel 9 is detecting external light and the wristwatch 1 is not in darkness, it is determined that the wristwatch 1 is in use and normal hand rotating operation is performed (step S121).
When the solar panel 9 is not detecting the external light and it is determined that the wristwatch 1 is in darkness, it is determined whether or not the current time is in a time zone between ten p.m. and five fifty a.m. (step S122). When the current time is not included in the time zone, it is determined that the wristwatch 1 is in use and normal hand rotating operation is performed (step S121). When the current time is included in the time zone, it is determined whether or not the solar panel 9 is detecting external light and generating electricity at predetermined time intervals e.g., at every ten minutes, to determine whether or not the wristwatch 1 has been in darkness for a predetermined time period, for example, about 61-70 minutes (step S123).
When the wristwatch 1 has not been in darkness for the predetermined time period, it is determined that the wristwatch 1 is in use and the normal hand rotating operation is performed (step S121). When the wristwatch 1 has been in darkness for the predetermined time period, it is then determined that the wristwatch 1 is not in use and in a sleep state (step S124). In the sleep state, only the seconds hand 2 rotates to the reference position (00-second position) and stopped, and the center and hour hands 3 and 4 rotate normally. Then, it is determined whether or not the solar panel 9 has never detected external light for 6 or 7 days and the wristwatch has been in darkness (step S125).
When the solar panel 9 has detected external light once or more in the 6 or 7 days and the wristwatch 1 has not always been in darkness, it is determined that the wristwatch is set in the sleep state. The flow returns to step S124 and processing of steps S124 and S125 is repeated. When the solar panel has not detected external light for 6 or 7 days and the wristwatch 1 has always been in darkness, it is determined that the wristwatch 1 has not been used for a long time. Thus, it is determined that the wristwatch 1 is in a complete sleep state in which rotation of the hands is stopped until use of the wristwatch 1 is started (step S126). In the complete sleep state, the seconds, center and hour hands 2, 3 and 4 rotate to the reference position (0-o'clock 00-minute 00-second position) and stopped.
Next, referring to
When the hand position detecting process is started, it is determined whether or not it is five minutes before the hour (step S130). When it is not five minutes before the hour, the hand position detecting process is not executed and the flow is terminated. When it is five minutes before the hour, it is determined whether or not the wristwatch 1 is in the complete sleep state in which the wristwatch 1 has been in darkness for a long time (step S131).
When the wristwatch 1 is in the complete sleep state, the hand position detecting process is not executed and the flow is terminated. When the wristwatch 1 is not in the complete sleep state, it is further determined whether or not the wristwatch 1 is in the sleep state in which the wristwatch 1 has been in darkness for about 61 to 70 minutes in the time zone between ten p.m. and five fifty a.m. (step S132). When it is determined in step S132 hat the wristwatch 1 is not in the sleep state, the wristwatch 1 is considered to be in the normal hand rotating operation. Then, the hard position detecting operation of
When it is determined in step S132 that the wristwatch 1 is in the sleep state, the seconds hand 2 is rotated to the reference position (00-second position) and stopped (step S134). Then, when it is five minutes before the hour, the hand position detecting is performed by rotating the center and hour hands 3 and 4 (step S135). In step S135, since the seconds hand 2 is stopped at the reference position (00-second position), the hand posit on detection is performed be rotating only the center and hour hands 3 and 4. When the hands are positioned correctly, the flow is terminated. When the hands cannot be positioned correctly, a full correction operation is executed, and then, the flow is terminated.
Next, referring to
When the error processing is started, it is determined whether or not the current time is five minutes before the hour (step S140). When it is not five minutes before the hour, the hand position detection is not performed and the flow is terminated. When it is five minutes before the hour, it is determined whether it is predetermined time or the wristwatch 1 has been in darkness for predetermined days (step S141).
That is, in step S141, it is determined whether or not it is the predetermined time, i.e., ten fifty-five a.m. or p.m. or it is determined whether or not the wristwatch 1 has beer in darkness for predetermined days, i.e., three or seven days. When it is ten fifty-five a.m. or p.m. or when the wristwatch 1 has been in darkness for three or seven days, an error counter A is cleared (step S142). Then, it is determined whether or not the wristwatch 1 has been in darkness for a log period and in the complete sleep state (step S143). When it is determined in step S141 that it is not ten fifty-five a.m. or p.m. and the wristwatch 1 has not been in darkness for three or seven days, the flow goes to step S143 to determine whether or not the wristwatch 1 is in the complete sleep state.
When it is determined that the solar panel 9 has not received external light for about six or seven days and the wristwatch 1 has been in darkness for a long period, it is determined that the wristwatch 1 is not in use and in the complete sleep state in step S143. The seconds, center and hour hands 2, 3 and 4 rotate to the reference position (0-o'lock 00-minute 50-second position) and stopped. Then, the flow is terminated. When it is determined that he solar panel 9 has received external light in six or seven days, it is determined that the wristwatch 1 is not in the complete sleep state in step S143. Then, it is determined whether or not the wristwatch 1 is in the sleep state (step S144).
In step S144, it is determined at every ten minutes, in the time zone between ten p.m. and five fifty a.m., whether or not the solar panel 9 has received external light for about 61 to 70 minutes. If the solar panel has received external light, it is determined that the wristwatch 1 is in use, the normal hand position detecting operation shown in
In step S146, when the value of the error counter is equal to or larger than the predetermined number of times, the seconds, center and hour hands 2, 3 and 4 rotate to the reference position and stopped, and the flow is terminated without executing the hand position detecting process. When it is determined that the value of the error counter A is smaller than the predetermined number of times, the seconds, center and hour hands rotate, and the hand position detecting process (
The hand position detecting device includes the solar panel 9 and the push-button switches SWs which trigger cancellation of the sleep and complete sleep states. When the solar panel 9 receives external light to generate electricity, it is determined that the wristwatch 1 is not left in darkness, and the sleep or complete sleep state is cancelled. When the push-button switches SWs are operated, it is determined that the wristwatch 1 is in use and the sleep or complete sleep state is cancelled.
As described, according to the hand position detecting device of the hand type wristwatch 1, the solar panel 9 which functions as darkness detector, allows making determination whether or not the wristwatch 1 is in darkness. When the wristwatch 1 has been in darkness for a predetermined time period, e.g., 61 to 70 minutes, a dark state determining section (CPU 35; steps S100 to S124) determines that the wristwatch 1 is not in use and set in the sleep state. In the sleep state, a hand rotation controlling section (CPU 35; steps S124 to S135) rotates at least seconds hand 2 from the seconds, center and hours hands 2, 3 and 4 to the reference position (00-second position) and stops the seconds hand 2. A hand position detecting section (CPU 35; steps S35 to S81) detects positions of the center and hour hands 3 and 4. Therefore, when the wristwatch 1 is not in use, the hand position detection is simplified and battery drain can be prevented.
In the state where the seconds hand 2 is stopped at the reference position (00-second position) under the control of the hand rotation controlling section (CPU 35; steps S124 to S135), the hand position detecting section (CPU 35; steps S35 to S87) detects the positions of the center and hour hands 3 and 4 at five minutes before the hour, and even in the sleep state in which the wristwatch 1 is not in use, the center and hour hands 3 and 4 can be rotated correctly. Therefore, when the sleep state is cancelled, the seconds hand 2 is immediately rotated to a position of the current time to correctly indicate the current time.
The hard position detecting device includes a detection stopping section (CPU 35; steps S140- to S149). The detection stopping section stops the hand position detection by the hand position detecting section until a predetermined time point, e.g., ten fifty-five a.m. or ten fifty-five p.m. or stops the detection for a predetermined time period, e.g., three or seven days, when the hand position detecting section cannot detect the positions of the seconds, center and hour hands 2, 3 and 4 successively a predetermined number of times, e.g., three times, in the state where the seconds hand 2 is stopped at the reference position under the control of the hand rotation controller (CPU 33; steps S124 to S135). Therefore, detection of the hand positions is not repeated unnecessarily when the hand position cannot be detected and battery drain can be prevented.
The hand position detecting device includes a hand rotation stopping section (CPU 35; steps S140 to S149). After the dark state determining section determines that the wristwatch 1 is in darkness, when the dark state has been continued for a few days, e.g., six or seven days, it is determined that the wristwatch 1 is not in use. Thus, the hand rotation stopping section rotates the seconds, center and hour hands 2, 3 and 4 to the reference position (0-o'clock 00-minute 00-second position) and stops the hands. Therefore, battery drain can he prevented in the case where the wristwatch 1 is not used for a long period.
The solar panel 9 and the push-button switches SWs trigger releasing stoppage of the hands. When the seconds hand 2 is stopped under the control of the hand rotation controlling section (CPU 35; steps S124 to S135), the stoppage of the seconds hand 2 is released in response to the trigger. When the seconds, center and hour hands 2, 3 and 4 are stopped under the control of tho hand rotation stopping section (CPU 35; steps S140 to S149), the stoppage of the seconds, center and hour hands 2, 3 and 4 is released in response to the trigger. Thus, the stoppage of the hands can he readily released when starting usage of the wristwatch 1.
For example, when a user wears the wristwatch 1 and carries the wristwatch 1 to a place where external light can be received, the solar panel 9 receives the external light and generates electricity. It is determined that the wristwatch 1 is in use, and the stoppage of the seconds, center and hour hands 2, 3 and 4 is immediately released to rotate the hands. When the push-button switches SWs are operated, it is determined that the wristwatch 1 is in use. The stoppage of the seconds, center and hour hands 2, 3 and 41 is immediately released to rotate the hands.
First Modification
In the above embodiment, the center hand position detecting process is executed as follows. That is, the center hand 25 rotates by one step at a time; one of the second light-passing apertures 28 and one of the fourth light-passing apertures 30 are aligned together at the detection position P and the detection unit 13 succeeds in light detection; the center hand 25 is reversed 20 steps from the position where the detection unit 13 succeeds in light detection; the center wheel 25 is fast rotated six steps from the reversed position, that is, the center wheel 25 is reversed 14 steps from the position where the detection unit 13 succeeds in light detection; then, the center wheel 25 is again rotated by one step at a time; and the reference position is determined when the detection unit 13 first succeeds in light detection. However, the invention is not limited to the embodiment. For example, the center hand position detecting process shown in
As shown in
Even after the center wheel 25 rotates 360 degrees (one hour), when the detection unit 13 detects no light, it is determined that the first light-passing apertures 21 are out of the detection position P. The seconds hand 20 is rotated 30 steps (180 degrees) to set one of the first light-passing apertures 21 at the detection position P (step S156). Then, the flow returns to step S150 and the counter S is cleared to be “0”. Then, the processing of steps S151 to S155 is repeated.
When the detection unit 13 succeeds in detecting light in step S154, it is determined that the center wheel 25 is positioned at the reference position (00-minute position), and the value of the counter S is stored in the RAM 17. Then, it is determined whether or not the stored value of the counter S is equal to or smaller than a predetermined number of steps, e.g., 12 steps (S≦12) (step S157). That is, when the center wheel 25 rotates 12 steps, the second light-passing aperture 28 is supposed to be completely away from the detection position P. However, the detection unit 13 may erroneously detects light due to a manufacturing error occurred during assembly.
Therefore, when the value of the counter S, i.e., the number of steps which the center wheel 25 has rotated is equal to or smaller than 12 steps when the detection unit 13 detects light at step S154, it is required to confirm whether or not the center wheel 25 is correctly set at the reference position. Thus, the center wheel 25 is reversed 12 steps (12 degrees) or more from the position where the detection unit 13 succeeds in light detection in step S154 (step S158) to move the second light-passing aperture 28 almost completely away from the detection position P. The center wheel 25 is rotated again one step (step S159), and the light emission element 31 emits light (step S160). It is determined whether or not the light from the light emission element 31 is received by the photo detection element 32, namely, whether or not the detection unit succeeds in light detection (step S161).
If not, the processing of steps S158 to S161 is repeated until the center wheel 25 rotates 12 steps or more (step S162). It is assumed that the detection unit 13 necessarily detects light in step S161 until the center wheel rotates 12 steps. However, if the detection unit 13 fails in detecting light, a hand position detection error is reported by means of a stop position of the seconds hand 2 or buzzer sound (step S163). When the detection unit 13 succeeds in detecting light in step S161, it is determined the center wheel 25 is set at the reference position (00-minute position) (step S164), and the process is terminated.
When it is determined in step S157 that the number of rotated steps of the center wheel 25 is larger than the predetermined number of steps, i.e., 12 steps, it is understood that the second and fourth light-passing apertures 28 and 30 are aligned together at the detection position P after the center wheel 23 rotates 360 degrees or more and the second light-passing aperture 28 rotates 12 degrees or more. Therefore, the state of the center wheel 25 is changed from that of
As described, according to the first modification, the hand position detecting device includes a counting section (CPU 35; step S152) to count the number of rotated steps of the center wheel 25, a memory (RAM 27) to store the number of steps counted by the counting section when the detection unit 13 detects light passing through the apertures, and a resetting section (CPU 35; step S150) to reset the number of steps counted by the counting section when the detection unit 13 detects no light even after the center wheel 25 rotates 360 degrees. When the detection unit 13 detects no light since the seconds wheel 20 blocks the detection position P, the counted number of steps is cleared and reset by the resetting section. Therefore, the counting section can count the number of rotated steps of the center wheel 25 correctly. The counted number of steps is stored in the memory; therefore, it can be determined whether or not the stored number of steps is equal to the predetermined number of steps.
When the number of steps stored in the memory 37 is larger than the predetermined number of steps (12 steps) the processing of reversing the center wheel 25 and confirming the center hand position is omitted, and a center hand position determining section (CPU 35; step S157) determines that the position where the detection unit 13 succeeds in light detection is the reference position. Therefore, when it is determined that the number of rotated steps of the center wheel 25 is larger than the predetermined number of steps, i.e., 12 steps, it is understood that the second and fourth light passing apertures 28 and 30 are aligned together at the detection position P after the center wheel 23 rotates 360 degrees or more and the second light-passing aperture 28 rotates 12 degrees or more. Thus, even when the processing of returning the center wheel 25 and confirming the center hand position (steps S158 to S163) is omitted, the reference position of the center wheel 25 can be determined correctly.
Second Modification
In the above embodiment, the first light-passing apertures 21 in the seconds wheel 20 include the first and second arcuate apertures 21b and 21c. However, the invention is not limited to the embodiment. The apertures may be configured as shown in
According to the second modification, the first arcuate aperture 21b is divided into two arcuate apertures 240a and 240b, and the second arcuate aperture 21c is divided into two arcuate apertures 241a and 241b.
The arcuate aperture 240a which is next to the circular aperture 21a is formed between 48 and 96 degrees from the center of the circular aperture 21a. The arcuate aperture 240a has a width corresponding to 60 degrees that is five times longer than the diameter of the circular aperture 21a. The arcuate aperture 240b is formed between 120 and 168 degrees from the center of the circular aperture 21a. The arcuate aperture 240b has a width corresponding to 60 degrees that is five times longer than the diameter of the circular aperture 21a. A fifth light blocking area 242 is formed between the arcuate apertures 240a and 240b. The fifth light blocking area 242 is diametrically opposed to a part of the arcuate aperture 241a.
The arcuate aperture 241a which is next to the circular aperture 21a is formed between 60 and 96 degrees from the center of the circular aperture 21a. The arcuate aperture 241a has a width corresponding to 48 degrees that is four times longer than the diameter of the circular aperture 21a. The arcuate aperture 241b is formed between 120 degrees and 168 degrees from the center of the circular aperture 21a. The arcuate aperture 240b has a width corresponding to 60 degrees that is five times longer than the diameter of the circular aperture 21a. A sixth light blocking area 243 is formed between the arcuate apertures 241a and 241b. The sixth light blocking area 243 is diametrically opposed to a part of the arcuate aperture 240a.
In the same manner as the embodiment, the arcuate aperture 240a is spaced from the circular aperture 21a by the first light blocking area 21d. The arcuate aperture 241a is also spaced from the circular aperture 21a by the second light blocking area 21e. The third light blocking area 21f is formed between the arcuate apertures 240b and 241b and diametrically opposed to the circular aperture 21a.
The first light blocking area 21d is formed between 0 and 48 degrees from the center of the circular aperture 21a. The first light blocking area 21d has a width corresponding to 36 degrees that is three times longer than the diameter of the circular aperture 21a. The first light blocking area 21d is diametrically opposed to the arcuate aperture 241b. The second light blocking area 21e is formed between 0 and 60 degrees from the center of the circular aperture 21a. The second light blocking area 21e has a width corresponding to 48 degrees that is four times longer than the diameter of the circular aperture 21a. The second light blocking area 21e is diametrically opposed to the arcuate aperture 240b. The third, fifth and sixth light blocking areas 21f, 242 and 243 have the almost same size as the circular aperture 21a. The third, fifth and sixth light blocking areas 21f, 242 and 243 are diametrically opposed to the circular aperture 21a and arcuate apertures 241a and 240b.
According to thus configured seconds wheel 20, in the case where one of the first to third, fifth and sixth light blocking areas 21d to 21f, 242 and 243 is positioned at the detection position P of the detection unit 13, when the seconds wheel 20 rotates 30 steps (180 degrees), one of the circular aperture 21a and the arcuate apertures 240a, 240b, 241a and 241b is necessarily located to the detection position P, similarly to the above described embodiment. In addition, the first arcuate aperture 21b is divided by the fifth light blocking area 242 into the arcuate apertures 240a and 240b, and the second arcuate aperture 21c is divided by the sixth light blocking area 243 into the arcuate apertures 241a and 241b. Therefore, strength of the seconds wheel 20 is improved in comparison with the above embodiment.
Third Modification
In the above described embodiment and the second modification, the first light blocking area 21d is formed between the circular aperture 21a and the first arcuate aperture 21b (or arcuate aperture 240a) and has the width that is three times longer than the diameter of the circular aperture 21a, and the second light blocking area 21e is formed between the circular aperture 21a and the second arcuate aperture 21c (or arcuate aperture 241a) and has the width that is four times longer than the diameter of the circular aperture 21a. The invention is not limited to the above configuration. The apertures may be configured as shown in
According to the third modification, the first light blocking area 21d is formed between 0 and 36 degrees from the center of the center of the circular aperture 21a. The first light flocking area 21d has a width corresponding to 24 degrees that is two times longer than the diameter of the circular aperture 21a. The second light blocking area 21e is formed between 0 and 48 degrees from the center of the circular aperture 21a. The second light blocking area 21e has a width corresponding to 36 degrees that is three times longer than the diameter of the circular aperture 21a.
Similarly to the second modification, the first arcuate aperture 21b is divided into two arcuate apertures 240a and 240b. The fifth light blocking area 242 is formed between the arcuate apertures 240a and 240b. The arcuate aperture 240a which is next to the circular aperture 21a is formed between 36 and 96 degrees from the center of the circular aperture 21a. The arcuate aperture 240a has a width that is expended toward the circular aperture 21a by the diameter of the circular aperture 21a in comparison with the second modification.
Similarly to the second modification, the second arcuate aperture 21c is divided into two arcuate apertures 241a and 241b. The sixth light blocking area 243 is formed between the arcuate apertures 241a and 241b. The arcuate aperture 241a which is next to the circular aperture 21a is formed between 264 and 312 degrees from the center of the circular aperture 21a. The arcuate aperture 241a has a width that is expended toward the first circular aperture by the diameter of the circular aperture 21a in comparison with the second modification.
The first light blocking area 21d is diametrically opposed to the arcuate aperture 241b. The second light blocking area 21e is diametrically opposed to the arcuate aperture 240b. The third, fifth and sixth light blocking areas 21f, 242 and 243 are diametrically opposed to the circular aperture 21a and the arcuate apertures 241a and 240a, respectively.
According to thus configured seconds wheel 20, in the case where one of the first to third, fifth and sixth light blocking areas 21d to 21f, 242 and 243 is positioned at the detection position P of the detection unit 13, when the seconds wheel 20 rotates 30 steps (180 degrees), one of the circular aperture 21a and the arcuate apertures 240a, 240b, 241a and 241b is necessarily located at the detection position P, similarly to the above described embodiment and the second modification.
In addition, since the first light blocking area 21d has the width that is two times longer than the diameter of the circular aperture 21a and the seconds wheel 20 rotates by one step (six degrees) at a time, when the seconds wheel 20 rotates four steps (24 degrees), the first light blocking area 21d passes over the detection position P. Then, when the seconds wheel 20 rotates further two steps (six seconds in total); a part of the arcuate aperture 40a comes to the detection position P. Thus, the rotational position of the seconds wheel 20 can be detected in six seconds. Therefore, when deviation of the position of the seconds hand is within one hour, it can be confirmed in a shorter period of time whether the position of the seconds hand 2 is correctly set or not.
In addition, the second light blocking area 21e has the width that is three times longer than the diameter of the circular aperture 21a. When counting the number of times of detection failure due to the second light blocking area 21e, when the detection unit 13 detects the circular aperture 21a after the number of times of detection failure comes to three, the position where the detection unit detects light is determined to be the reference position (00-second position) of the seconds wheel 20. Therefore, the reference position of the seconds wheel 20 can be detected in a shorter period of time in comparison with above embodiment, and detection speed is improved.
In the above embodiment, and first to third modifications, the hand position detection for the seconds, center and hour hands 2, 3 and 4 is stopped from the time point when three hand position detection errors are successively detected to a few minute before the specific time point (ten fifty-five). However, the invention is not limited to the above configuration. The hand position detection for the second, center and hour hands 2, 3 and 4 may be stopped from the time point when a predetermined numbers of hand position detection errors (i.e., three errors) are successively detected to a time point when the wristwatch 1 is set in the sleep state in which the wristwatch 1 is not used for a long period. Such configuration can prevent large consumption of the battery.
In the above embodiment and modifications, the hand-position detecting process is executed every five minutes before the hour. However, execution of the process is not limited to five minutes before the hour. The process may be executed 1-10 minutes before the hour.
In the above embodiment and modifications, the circular aperture 21a, second and third light-passing apertures 28 and 29 are formed in a circular shape. However, the shape of the apertures is not limited to the circular shape. The apertures may be formed in a square, trapezoidal or polygonal shape.
In the above embodiment and modifications, the hand position detection device is applied to the hand type wristwatch 1. However, the hand position detection device may be employed by various types of hand type timepiece such as a travel watch, alarm watch, standing clock, and wall clock.
While the description above refers to particular embodiments and modifications of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention. The presently disclosed embodiments and modifications are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. For example, the present invention can be practiced as a computer readable recording medium in which a program for allowing the computer to function as predetermined means, allowing the computer to realize a predetermined function, or allowing the computer to conduct predetermined means.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-139127 | May 2008 | JP | national |
