JP7499604B2 - Electronic clock - Google Patents

Description

The present invention relates to an electronic watch.

Patent Document 1 discloses an electronic watch that includes a number of resistors corresponding to the ranks of the power generation capacity of a solar panel, and is equipped with technology that determines the rank (power generation level) of the power generation capacity by sequentially switching the switches corresponding to those resistors on and off.
Patent Document 2 discloses an electronic timepiece equipped with technology that detects the amount of power generated by a solar panel through user operation and causes a hand to indicate a position on a power generation level display section that corresponds to the power generation level.

JP 2015-177556 A JP 2015-175602 A

Here, in the electronic watches disclosed in Patent Documents 1 and 2, even when the same amount of light is incident, the amount of power generated by the solar panel varies depending on the transmittance of the dial placed on the light-receiving side of the solar panel and the material and shape of the solar cell. For example, the amount of power generated is relatively small in electronic watches that use black dials with low transmittance. Therefore, in electronic watches that can display the power generation level, it may become difficult to indicate a high power generation level, or it may not indicate a high power generation level at all. This narrows the range of movement of the pointer indicating the power generation level, making it difficult for the user to recognize changes in the power generation level.

The object of the present invention is to provide an electronic watch that improves the visibility of changes in power generation level by preventing the range of movement of the hands from becoming narrower.

The invention disclosed in this application has various aspects to solve the above problems, and the most representative aspects are outlined below.

(1) An electronic watch having a solar panel that generates power by receiving external light, a power generation level determination unit that determines the power generation level of the solar panel, a power generation level display, a pointer that moves to a position on the power generation level display according to the power generation level, and a setting unit that sets the power generation level corresponding to the upper limit position within the range from the lower limit position to the upper limit position of the pointer that points to the power generation level display.

(2) In the electronic watch of (1), the setting unit sets the power generation level corresponding to the upper limit position according to the expected power generation amount.

(3) In (2), the estimated power generation amount is an estimated power generation amount according to the transmittance of the dial. An electronic watch.

(4) In (2), the expected power generation amount is the amount of power generation expected according to the characteristics of the solar panel. An electronic watch.

(5) An electronic watch according to any one of (1) to (4), comprising a plurality of detection resistors, a connection control unit that sequentially switches the electrical connection state between the solar panel and a connection target resistor that is a part of the plurality of detection resistors, and the power generation level determination unit determines the power generation level based on a detection voltage detected when the solar panel is electrically connected to at least one of the connection target resistors.

(6) In (5), the number of the plurality of detection resistors is greater than the number of power generation levels.

(7) An electronic watch according to (1), comprising at least one capacitor electrically connected to the solar panel, and a counting unit that counts at least one of a charge time and a discharge time of the capacitor that is charged with an electric charge supplied from the solar panel irradiated with a predetermined amount of light, and the setting unit sets a power generation level corresponding to the upper limit position based on at least one of the charge time and the discharge time counted by the counting unit.

(8) In the electronic watch of (7), the counting unit counts at least one of a first count value until the charge amount of the capacitor becomes equal to or greater than a first threshold value and a second count value until the charge amount of the capacitor becomes equal to or less than a second threshold value when the electronic watch is in use, and the power generation level determining unit determines the power generation level of the solar panel based on at least one of the first count value and the second count value.

(9) In (7) or (8), an electronic watch has two or more of the capacitors, the two or more capacitors being connected in parallel.

(10) In (9), an electronic watch has a connection control unit that switches the connection state between the two or more capacitors and the solar panel so that one of the two or more capacitors is charged while the other capacitor is discharged.

(11) In (9) or (10), an electronic watch has a switch that can switch the two or more capacitors into a series connection.

(12) In any one of (7) to (11), an electronic watch has a plurality of discharge resistors electrically connected to the capacitor, and a switch capable of switching the connection state between the capacitor and the plurality of discharge resistors.

(13) In (12), the electronic watch has the plurality of discharge resistors each having a different resistance value.

(14) In any one of (1) to (13), the upper limit position is a position indicating 30 seconds.

(15) In any one of (1) to (14), the setting unit sets the power generation level corresponding to a position other than the upper limit position based on the power generation level corresponding to the upper limit position set by the setting unit. An electronic watch.

(16) An electronic watch according to any one of (1) to (15), having a memory unit that stores each of the power generation levels in association with the position of the hands.

According to aspects (1) to (16) of the present invention, it is possible to provide an electronic watch that improves the visibility of changes in power generation level by preventing the range of movement of the hands from becoming narrower.

FIG. 1 is a plan view showing an electronic timepiece according to a first embodiment. 1 is a block diagram showing an outline of the system configuration of an electronic timepiece according to a first embodiment. FIG. 4 is a plan view showing an example of a display mode of a power generation level in the first embodiment. FIG. 2 is a circuit diagram showing a control circuit in the first embodiment. FIG. 4 is a diagram illustrating an example of a table stored in a storage unit of the first embodiment. FIG. 4 is a diagram illustrating an example of a table stored in a storage unit of the first embodiment. 5 is a flowchart showing an operation of a control circuit in the first embodiment. FIG. 11 is a block diagram showing an outline of the system configuration of an electronic timepiece according to a second embodiment. FIG. 11 is a circuit diagram showing a control circuit according to a second embodiment. FIG. 11 is a circuit diagram showing a control circuit according to a second embodiment. FIG. 11 is a circuit diagram showing a control circuit according to a second embodiment. 11 is a graph showing the change in the charge amount of a capacitor during the process of setting the power generation level corresponding to the upper limit position. 11 is a graph showing a change in the charge amount of a capacitor during a power generation level determination process. 13 is a flowchart of a process for setting a power generation level corresponding to an upper limit position in a second embodiment. 10 is a flowchart showing a power generation level determination process in the second embodiment. FIG. 13 is a circuit diagram showing a control circuit in a first modified example of the second embodiment. FIG. 13 is a circuit diagram showing a control circuit in a second modified example of the second embodiment. FIG. 13 is a circuit diagram showing a control circuit according to a third embodiment.

Each embodiment of the present invention will be described in detail below with reference to the drawings.

Figure 1 is a plan view showing an electronic timepiece according to a first embodiment. Figure 1 shows a case 10 which is the exterior case of the electronic timepiece 1, a dial 14 arranged within the case 10, and an hour hand 15, minute hand 16, and second hand 17 which indicate the time. The dial 14 also has hour characters 19 at predetermined positions. Band fixing parts 11 for fixing the band extend from the sides of the case 10 on the 12 o'clock and 6 o'clock sides. Additionally, a button 12 and a crown 13 which are operating parts that allow the user to perform various operations are arranged on the side of the case 10 on the 3 o'clock side. The various functions of the electronic timepiece 1 are executed by the user operating the operating parts.

The dial 14 also has a small window 14a. A date wheel is disposed on the back side of the dial 14, and the date displayed on the date wheel can be seen from the outside through the small window 14a. In FIG. 1, the number "7", indicating the "7th", is shown as being seen through the small window 14a. The small window 14a may be a through hole or may be made of a transparent material. In this embodiment, the small window 14a is disposed at the 3 o'clock position, and also functions as an hour character 19.

Although not shown in FIG. 1, in the first embodiment, a solar panel 30 (see FIG. 2 described later) that generates electricity by receiving light is disposed on the back side of the dial 14. The solar panel 30 is preferably attached to a movement (not shown) housed in the case 10. The movement is a unit in which the drive mechanism 70 (see FIG. 2 described later) and a watch circuit board on which a control circuit 40 (see FIG. 2 described later) that is responsible for the timekeeping function are mounted are integrally assembled to a frame called the base plate.

The solar panel 30 generates electricity from the light that passes through the dial 14. For this reason, the dial 14 is made of a material that transmits light to a certain extent.

The electronic watch 1 may be a radio-controlled watch that has the function of receiving standard radio waves or satellite signals containing time information from GPS (Global Positioning System) satellites and the like to correct the internal time, or it may be a radio-controlled watch that transmits and receives data to and from external devices using Bluetooth (registered trademark), Wi-Fi (registered trademark), or NFC.

As shown in FIG. 1, the dial 14 may be provided with a small window 14c in which an auxiliary hand 14b is placed. The auxiliary hand 14b may display various information such as the radio reception status, the time zone, and the remaining charge of the secondary battery 60 (see FIG. 2, described below). Note that multiple auxiliary hands 14b and small windows 14c may be provided on the dial 14 depending on the functions of the electronic watch 1.

Note that the design of the electronic watch 1 shown in FIG. 1 is just one example. In addition to what is shown here, for example, the case 10 may be rectangular instead of round, and the presence, number, and placement of the buttons 12 and crown 13 are optional.

Figure 2 is a block diagram showing an outline of the system configuration of the electronic watch according to the first embodiment. In addition to the configuration shown in Figure 1, the electronic watch 1 includes a solar panel 30, a control circuit 40, a secondary battery 60, and a drive mechanism 70.

The control circuit 40 includes a memory unit 41, a setting unit 42, a connection control unit 43, a power generation level determination unit 44, and a detection resistor circuit 45. The control circuit 40 is a microcomputer with built-in memory, and controls the operation of various circuits included in the electronic watch 1 according to the programs stored in the memory.

The storage unit 41 constitutes part of the memory described above, and may store various tables, etc., that are used when performing the power generation level determination process described below.

The setting unit 42 sets the power generation level corresponding to the upper limit position of the second hand 17 within the range from the lower limit position to the upper limit position. The connection control unit 43 sequentially switches the electrical connection state between the solar panel 30 and the connection target resistor. The power generation level determination unit 44 determines the power generation level of the solar panel 30 based on the detection voltage detected when the solar panel 30 and the connection target resistor are electrically connected. Details of the setting unit 42, connection control unit 43, power generation level determination unit 44, and detection resistor circuit 45 will be described later.

The secondary battery 60 may be, for example, a lithium ion battery. The drive mechanism 70 includes various gears and drives the hands such as the hour hand 15, minute hand 16, and second hand 17.

As shown in FIG. 2, the solar panel 30 is configured to be connectable to the secondary battery 60 via the switch 29. When the switch 29 electrically connects the solar panel 30 and the secondary battery 60 in response to a command from the control circuit 40, the power generated by the solar panel 30 is supplied to the secondary battery 60. On the other hand, as shown in FIG. 2, when the switch 29 cuts off the electrical connection between the solar panel 30 and the secondary battery 60 in response to a command from the control circuit 40, no power is supplied to the secondary battery 60 even if the solar panel 30 generates power.

Now, referring to FIG. 3, we will explain the display mode of the power generation level of the solar panel 30 in the electronic watch 1 according to the first embodiment. FIG. 3 is a plan view showing an example of the display mode of the power generation level in the first embodiment. In FIG. 3, the second hand 17 is shown indicating power generation level 2 (10-second position). The second hand 17 is also shown by a dashed line when indicating another power generation level. Note that the power generation level indicates the magnitude of the power generation amount of the solar panel 30.

In the electronic watch 1 according to the first embodiment, as shown in FIG. 3, the second hand 17 moves to indicate the current power generation level. Here, the hour 19 pointed to by the second hand 17 functions as a power generation level indicator. FIG. 3 shows the second hand 17 moving to positions indicating 0, 5, 10, 15, 20, 25, and 30 seconds, in ascending order of power generation level. By adopting such a configuration, the user can visually recognize whether the electronic watch 1 is in an environment where it is easy to receive light, that is, whether the solar panel 30 is in an environment where it is easy to generate power. In addition, by indicating the power generation level using the second hand 17, visibility can be improved compared to a configuration in which the power generation level is indicated by the auxiliary hand 14b or the like. Note that the power generation level is indicated by the second hand 17 when the electronic watch 1 is switched from a time display mode to a power generation level display mode, for example, by the user operating the button 12 or the crown 13.

As shown in FIG. 3, the visible surface of the dial 14 is provided with a band-shaped display 50 that overlaps with and extends along the movement path of the second hand 17. The band-shaped display 50 functions as a power generation level display. The band-shaped display 50 becomes thicker from the 0 second side to the 30 second side (from the 12 o'clock side to the 6 o'clock side), and is arranged to indicate that the power generation level on the 0 second side, which is the lower limit, is low and the power generation level on the 30 second side, which is the upper limit, is high. By adopting such a configuration, the user can easily visually recognize whether or not the solar panel 30 is in an environment that is conducive to power generation.

In the first embodiment, the hour digits 19 and the band display 50 are used as examples of power generation level indicators that have the function of displaying the power generation level by being pointed to by the second hand 17, but at least one power generation level indicator is sufficient.

Next, we will explain the power generation level determination process when the electronic watch 1 is in use. The power generation level determination process may be performed periodically, for example, every two seconds, or may be performed in response to the user's operation of the button 12 or the crown 13.

The current I that the solar panel 30 outputs as a result of power generation varies depending on the amount of light that the solar panel 30 receives. In other words, the greater the amount of light that the solar panel 30 receives, the greater the current I that the solar panel 30 outputs.

The power generation level determination unit 44 obtains the detection voltage (I x R) detected when the current I flows through the detection resistor R. The connection control unit 43 then connects the detection resistors R, each having a different resistance value, in order from the largest resistance value, and the power generation level determination unit 44 detects whether the detection voltage is greater than a predetermined threshold value. By connecting the detection resistors R in order from the largest resistance value, a large detection voltage (I x R) can be detected even when the current value is small (even in an environment with a small amount of power generation). This makes it clear whether the detection voltage is greater than the predetermined threshold value, and the power generation level can be easily determined.

Here, even when the same amount of light is incident on the electronic watch 1, individual differences and the like can cause variation in the amount of power generated by the solar panel 30. Examples of individual differences in electronic watches 1 include differences in the transmittance of the dial 14, differences in the material and shape of the solar panel 30, and differences in the number and shape of the solar cells that make up the solar panel.

For example, an electronic watch 1 that uses a dial 14 with low transmittance will have a smaller amount of power generation. This may make it difficult to indicate a high power generation level, or may not indicate a high power generation level at all. If it does not indicate a high power generation level, the range of motion of the second hand 17 will be narrowed, making it difficult for the user to recognize changes in the amount of power generation.

In the first embodiment, therefore, a configuration is adopted in which the power generation level corresponding to the upper limit position of the second hand 17 is set within the range from the lower limit position to the upper limit position according to the expected power generation amount. In the first embodiment, the lower limit position of the second hand 17 is set to the position indicating 0 seconds, and the upper limit position of the second hand 17 is set to the position indicating 30 seconds. In other words, the movable range of the second hand 17 when displaying the power generation level is set to between the 0 second position and the 30 second position. Also, in the first embodiment, the power generation level is divided into seven levels: 0, 1, 2, 3, 4, 5, and 6.

Figure 4 is a circuit diagram showing the control circuit in the first embodiment. Note that, although Figure 4 shows an example in which the detection resistance circuit 45 is incorporated in the same board as the control circuit 40, this is not limiting, and the detection resistance circuit 45 may be provided separately. Figure 5 is a diagram showing an example of a table stored in the memory unit of this embodiment.

The detection resistor circuit 45 includes detection resistors R1 to R30 connected in parallel and each having a different resistance value. In this specification, unless there is a need to distinguish between them, they will simply be called "detection resistors R". In the first embodiment, the resistance value of the detection resistor R1 is the largest, and the resistance value of the detection resistor R30 is the smallest. Then, multiple detection resistors R2 to R29 are arranged in a row so that the resistance value decreases from the detection resistor R1 to the detection resistor R30. Note that in FIG. 4, the detection resistor R and the like are omitted as appropriate to avoid cluttering the drawing. Note that the number of detection resistors R should be at least greater than the number of power generation levels.

As shown in FIG. 4, switches SW1 to SW30 are connected to the detection resistors R1 to R30, respectively. Similarly, switches SW1 to SW30 will be simply referred to as "switches SW" unless there is a need to distinguish between them. One end of each switch SW is connected to the detection resistor R, and the other end is grounded.

In the first embodiment, the setting unit 42 selects some of the 30 detection resistors R as the connection target resistors according to the expected power generation amount. Specifically, the power generation level is divided into seven stages, and six connection target resistors Rt1 to Rt6 are selected from the 30 detection resistors R1 to R30 according to the expected power generation amount. In this specification, unless there is a particular need to distinguish between them, they will be simply called "connection target resistors Rt". Furthermore, the switches corresponding to the connection target resistors Rt1 to Rt6 will be called connection target switches SWt1 to SWt6, respectively. Similarly, unless there is a particular need to distinguish between them, they will be simply called "connection target switches SWt".

In the first embodiment, the expected power generation amount is the expected power generation amount when a predetermined amount of light is incident depending on the transmittance of the dial 14, the material and shape of the solar panel 30, and other individual differences of the electronic watch 1. For example, if the dial 14 is a black dial with low transmittance, the expected power generation amount is small, and if the dial 14 is a white dial with high transmittance, the expected power generation amount is large.

In the first embodiment, as an example, a case where the dial 14 is a black dial with low transmittance, or a case where the dial 14 is a white dial with high transmittance will be described.

Figures 5 and 6 are diagrams showing examples of tables stored in the storage unit of the first embodiment. Specifically, Figure 5 shows a table used when the expected power generation amount is large (when the dial 14 is a white dial with a high transmittance), and Figure 6 shows a table used when the expected power generation amount is small (when the dial 14 is a black dial with a low transmittance).

Figure 5(a) is a table showing an example of a resistor to be connected that is used when the expected power generation amount is large in the first embodiment. Figure 5(b) is a table showing an example of the relationship between the detected voltage, power generation level, and second hand position when the table shown in Figure 5(a) is used.

Figure 6(a) is a table showing an example of a resistor to be connected that is used when the expected power generation amount is small in the first embodiment. Figure 6(b) is a table showing an example of the relationship between the detected voltage, power generation level, and second hand position when the table shown in Figure 6(a) is used.

When the expected power generation amount is large, as shown in FIG. 5(a), the detection resistors R5, R10, R15, R20, R25, and R30 may be used as the connection target resistors Rt1, Rt2, Rt3, Rt4, Rt5, and Rt6. As shown in FIG. 5(b), the setting unit 42 may set the power generation level corresponding to the 30-second position, which is the upper limit position of the second hand 17, to power generation level 6. The setting unit 42 may set the power generation level corresponding to a position other than the upper limit position based on the power generation level corresponding to the set upper limit position. In the first embodiment, the setting unit 42 sets the power generation levels corresponding to the 0-second position, 5-second position, 10-second position, 15-second position, 20-second position, and 25-second position to power generation levels 0 to 5, respectively.

Then, the connection control unit 43 sequentially switches the connection target switches SWt corresponding to the connection target resistors Rt. For example, the connection control unit 43 first connects the connection target switch SWt1 corresponding to the connection target resistor Rt1 having the largest resistance value among the connection target resistors Rt. Then, the power generation level determination unit 44 determines whether the detection voltage detected in the connection target resistor Rt1 due to the current I flowing is greater than a predetermined threshold value (output voltage value of the comparison voltage 44a).

When the power generation level determination unit 44 detects a detection voltage that is lower than a predetermined threshold value while the connection target switch SWt1 is connected, it determines that the power generation level is 0.

When the power generation level determination unit 44 detects a detection voltage equal to or greater than a predetermined threshold value while the connection target switch SWt1 is connected, the connection control unit 43 disconnects the connection target switch SWt1 and connects the connection target switch SWt2 corresponding to the connection target resistor Rt2, which has a smaller resistance value than the connection target resistor Rt1. The power generation level determination unit 44 then determines whether the detection voltage detected at the connection target resistor Rt2 is smaller than a predetermined threshold value (output voltage value of the comparison voltage 44a).

When the power generation level determination unit 44 detects a detection voltage lower than a predetermined threshold value while the connection target switch SWt2 is connected, the power generation level determination unit 44 determines that the power generation level is 1. When the power generation level determination unit 44 detects a detection voltage equal to or higher than a predetermined threshold value while the connection target switch SWt2 is connected, the connection control unit 43 disconnects the connection target switch SWt2 and connects the connection target switch SWt3 corresponding to the connection target resistor Rt3, which has a smaller resistance value than the connection target resistor Rt2. Then, in the same procedure as when the connection target switches SWt1 and SWt2 are connected as described above, the power generation level determination unit 44 determines whether the detection voltage is higher than a predetermined threshold value (output voltage value of the comparison voltage 44a). If the detection voltage is equal to or higher than the threshold value, the power generation level determination unit 44 repeats the connection with SWt6, and if it is determined that the detection voltage is equal to or higher than the threshold value even when connected with SWt6, the power generation level is determined to be 6 and the determination process ends.

The number of connected resistors Rt should be less than the number of detection resistors R, and should be at least two.

By performing the power generation level determination process using the table shown in Figure 5, each power generation level can be indicated by the second hand 17, as shown in Figure 3.

On the other hand, when the expected power generation amount is small, as shown in FIG. 6(a), the detection resistors R5, R7, R9, R11, R13, and R15 may be used as the connection target resistors Rt1, Rt2, Rt3, Rt4, Rt5, and Rt6. Also, as shown in FIG. 6(b), the setting unit 42 may set the power generation level corresponding to the 30 second position, which is the upper limit position of the second hand 17, to power generation level 3. Also, the setting unit 42 may set the power generation levels corresponding to the 0 second position, 5 second position, 10 second position, 15 second position, 20 second position, and 25 second position to power generation levels 0, 0.5, 1, 1.5, 2, and 2.5, respectively.

Then, the power generation level determination process can be performed by carrying out the same process as described above.

By performing the power generation level determination process using the table shown in FIG. 6, when the same amount of light is incident as when the power generation level is 3 using the table shown in FIG. 5, the second hand 17 will point to the upper limit position, which is 30 seconds.

In the first embodiment, the setting unit 42 may select whether to use the table shown in FIG. 5 or the table shown in FIG. 6. The selection of the table by the setting unit 42 may be performed, for example, when the manufacturer or seller performs the initial settings of the electronic watch 1. Alternatively, the selection may be performed by the user operating the button 12 or the crown 13.

The table selection by the setting unit 42 may be unchangeable from the initial setting, or may be changeable by the user's operation. If unchangeable from the initial setting, the detection resistors R that are not used as the connection target resistors Rt among the detection resistors R are not used in the power generation level determination process, and therefore may be irreversibly electrically disconnected from the power generation level determination unit 44.

In addition, if the table selection by the setting unit 42 is changeable from the initial setting, the storage unit 41 may store multiple tables such as those shown in Figs. 5 and 6. On the other hand, if the table selection by the setting unit 42 is not changeable from the initial setting, the storage unit 41 may store only one pattern of the table shown in Fig. 5 or 6.

In addition, if the table selection by the setting unit 42 can be changed from the initial setting, the device may have a function of displaying which setting is currently set using a pointer other than the pointer (second hand 17 in the first embodiment) that indicates the power generation level. For example, the power generation level corresponding to the current upper limit position may be displayed using the hour hand 15, minute hand 16, auxiliary hand 14b, etc. Specifically, if the power generation level corresponding to the current upper limit position is "3", the minute hand 16 may point to the 3 o'clock position (15 minute position) to allow the user to recognize the power generation level corresponding to the current upper limit position. Alternatively, multiple modes (e.g., modes 1 to 3) may be prepared according to the power generation level corresponding to the upper limit position, and the auxiliary hand 14b, etc. may point to the mode number to allow the user to recognize the power generation level corresponding to the current upper limit position.

Next, the operation flow of the power generation level determination process in the first embodiment will be described with reference to FIG. 7. FIG. 7 is a flowchart showing the operation of the control circuit in the first embodiment.

First, the control circuit 40 reads out a table stored in the memory unit 41 that is selected by the setting unit 42 based on the expected power generation amount (step S1). For example, it is preferable to read out the table shown in either FIG. 5(a) or FIG. 5(b) or FIG. 6(a) or FIG. 6(b).

Next, the connection control unit 43 switches the switch SW to connect the connection target resistor Rt1, which has the largest resistance value (step S2).

Then, the power generation level determination unit 44 compares the detected voltage I×Rt1 with a predetermined threshold Vth (Vth≦IRt1?) (step S3). If the detected voltage I×Rt1 is smaller than the predetermined threshold Vth (NO in step S3), the power generation level determination unit 44 determines that the power generation level is 0 (step S4).

If the detected voltage I×Rt1 is equal to or greater than the predetermined threshold value (YES in step S3), the connection control unit 43 switches the switch SW to connect the connection target resistor Rt2, which has the next smallest resistance value after the connection target resistor Rt1 (step S5).

Then, the power generation level determination unit 44 compares the detected voltage I×Rt2 with a predetermined threshold Vth (Vth≦IRt2?) (step S6). If the detected voltage I×Rt2 is smaller than the predetermined threshold Vth (NO in step S6), the power generation level determination unit 44 determines that the power generation level is 1 (step S7).

If the detected voltage I×Rt2 is equal to or greater than the predetermined threshold value (YES in step S6), the connection control unit 43 switches the switch SW to connect the connection target resistor Rt3, which has the next smallest resistance value after the connection target resistor Rt2 (step S8).

Then, the power generation level determination unit 44 compares the detected voltage I×Rt3 with a predetermined threshold Vth (Vth≦IRt3?) (step S9). If the detected voltage I×Rt3 is smaller than the predetermined threshold Vth (NO in step S9), the power generation level determination unit 44 determines that the power generation level is 2 (step S10).

If the detected voltage I×Rt3 is equal to or greater than the predetermined threshold value (YES in step S9), the connection control unit 43 switches the switch SW to connect the connection target resistor Rt4, which has the next smallest resistance value after the connection target resistor Rt3 (step S11).

Then, the power generation level determination unit 44 compares the detected voltage I×Rt4 with a predetermined threshold Vth (Vth≦IRt4?) (step S12). If the detected voltage I×Rt4 is smaller than the predetermined threshold Vth (NO in step S12), the power generation level determination unit 44 determines that the power generation level is 3 (step S13).

The same process as above can be carried out sequentially for the connected resistors Rt5 to Rt6.

The control circuit 40 may also operate the drive mechanism 70 based on the results of the power generation level determination process to move the second hand 17 to the corresponding second hand position.

The order of the connection target resistors Rt to be connected is not limited to that described in FIG. 7. For example, they may be connected in order from the lowest resistance value, or a connection target resistor Rt with an intermediate resistance value may be connected and judged, and the connection state may be switched so that the resistance value of the connection target resistor Rt is decreased or increased depending on the judgment result. In either case, the power generation level may be judged based on the detection resistor R that is in the connected state when the detection voltage becomes smaller than a predetermined threshold value or becomes equal to or larger than the predetermined threshold value.

As described above, in the first embodiment, regardless of individual differences in the electronic watch 1, the visibility of changes in the power generation level can be improved by increasing the range of movement of the second hand 17. In other words, the visibility of changes in the power generation level can be improved by preventing the range of movement of the second hand 17 from narrowing.

In the first embodiment, the power generation level is 6 when the solar panel 30 is hit by the maximum amount of light expected to be incident on it, and if this is not met, the power generation level corresponding to the upper limit position is set to a value lower than 6. Specifically, an example has been described in which the power generation level corresponding to the upper limit position is set to 3. However, this is not limiting, and in the first embodiment, for example, the power generation level corresponding to the upper limit position may be set to 4, taking into consideration a case in which the solar panel 30 is hit by an amount of light greater than the maximum amount of light expected to be incident on it.

Next, the second embodiment will be described with reference to Figs. 8 to 15. The basic configuration of the electronic watch 1 of the second embodiment is the same as that shown in Fig. 1. Also, in the second embodiment, as in the first embodiment, the movable range of the second hand 17 when displaying the power generation level is a position indicating 0 to 30 seconds. Note that the same reference numerals are used for the same configuration as that described in the first embodiment, and the description thereof will be omitted.

Figure 8 is a block diagram showing an outline of the system configuration of an electronic watch according to the second embodiment. Figures 9 to 11 are circuit diagrams showing a control circuit in the second embodiment. Figure 9 shows a state in which a current is supplied from a solar panel to a secondary battery. Figure 10 shows a state in which a current supplied from a solar panel is charged to a capacitor. Figure 11 shows a state in which an electric charge stored in a capacitor is discharged. Figure 12 is a graph showing the progress of the charge amount of a capacitor in the process of setting a power generation level corresponding to an upper limit position. Figure 13 is a graph showing the progress of the charge amount of a capacitor in the process of setting a power generation level. Figure 14 is a flowchart of the process of setting a power generation level corresponding to an upper limit position in the second embodiment. Figure 15 is a flowchart showing the process of determining a power generation level in the second embodiment.

As shown in FIG. 8, in the second embodiment, the control circuit 140 includes a capacitance circuit 46, a counting unit 47, and a charge amount detection circuit 42a. The capacitance circuit 46 is a circuit including at least a capacitor C. As shown in FIG. 9, the capacitor C included in the capacitance circuit 46 may be externally attached to the control circuit 140. The counting unit 47 counts the charge time and discharge time of the capacitor C. The charge amount detection circuit 42a detects the charge amount of the capacitor C.

9, the capacitance circuit 46 includes a capacitor C, a discharge resistor Rd, and switches SWc1 and SWc2. The control circuit 140 includes switches 29a and 29b. The connection control unit 43 (not shown in FIG. 9) switches the switches SWc1, SWc2, 29a, and 29b between connected and disconnected states.

Figure 9 shows that the secondary battery 60 is being charged by supplying a current I from the solar panel 30 to the secondary battery 60 (see the thick arrow in Figure 9). At this time, the connection control unit 43 sets the switches 29a and 29b to a connected state and the switches SWc1 and SWc2 to a disconnected state.

Figure 10 shows how capacitor C is being charged by current supplied from solar panel 30 (see the thick arrow in Figure 10). At this time, the connection control unit 43 has switches 29a and SWc1 in a connected state, and switches 29b and SWc2 in a disconnected state. By setting each switch to the state shown in Figure 10, current I from the solar panel 30 flows to capacitor C, and charge accumulates in capacitor C.

Figure 11 shows the state in which the charge accumulated in capacitor C is discharged (see the thick arrow in Figure 11). At this time, the connection control unit 43 sets switches SWc1 and SWc2 in a connected state and switches 29a and 29b in a disconnected state. By setting each switch to the state shown in Figure 11, the charge accumulated in capacitor C is discharged through discharge resistor Rd.

In the second embodiment, the counting unit 47 counts the charge time and discharge time of the capacitor C when a predetermined amount of light is irradiated onto the solar panel 30. The setting unit 42 then acquires the count value counted by the counting unit 47, and sets the power generation level corresponding to the upper limit position of the second hand 17 based on the acquired count value.

First, each switch is set to the state shown in FIG. 10, and a predetermined amount of light is irradiated onto the solar panel 30. This causes an electric charge to be stored in the capacitor C. As shown in FIG. 12, the amount of charge in the capacitor C increases during the charging period. The charging period ends when the amount of charge detected by the charge amount detection circuit 42a becomes equal to or greater than a predetermined threshold value Fth1.

The switches are then set to the states shown in FIG. 11. This causes the charge in capacitor C to be discharged. As shown in FIG. 12, the amount of charge in capacitor C decreases during the discharge period. The discharge period ends when the amount of charge detected by charge amount detection circuit 42a becomes equal to or less than a predetermined threshold value Fth2.

The counting unit 47 counts the time from the start of charging the capacitor C to the end of discharging. Figure 12 shows an example in which the time from the start of discharging the capacitor C to the end of discharging is time T. Time T is the time corresponding to the count value.

The setting unit 42 sets the power generation level corresponding to the upper limit position of the second hand 17 based on the count value in the counting unit 47. For example, when the count value is large, the time from when the capacitor C starts charging to when it finishes discharging is long, and the amount of power generation is small. On the other hand, when the count value is small, the time from when the capacitor C starts discharging to when it finishes discharging is short, and the amount of power generation is large.

Therefore, when the count value is large, the setting unit 42 may reduce the power generation level corresponding to the upper limit position of the second hand 17. For example, the setting unit 42 may set the power generation level corresponding to the upper limit position of the second hand 17 to 3. That is, in the power generation level determination process, when the power generation level is 3, the second hand 17 may indicate 30 seconds.

When the count value is small, the setting unit 42 may increase the power generation level corresponding to the upper limit position of the second hand 17. For example, the setting unit 42 may set the power generation level corresponding to the upper limit position of the second hand 17 to 6. That is, in the power generation level determination process, when the power generation level is 6, the second hand 17 may indicate 30 seconds.

The process of setting the power generation level corresponding to the upper limit position may be performed, for example, before the electronic watch 1 is shipped. The electronic watch 1 may then be shipped with the power generation level set to the upper limit position of the second hand 17.

In the second embodiment, the power generation level determination unit 44 determines the power generation level based on the time (count value) from the start of discharge to the end of discharge. FIG. 13 shows an example in which the charge period is a predetermined period, the discharge period starts after the charge period ends, and the discharge period ends when the charge amount detected by the charge amount detection circuit 42a becomes equal to or less than a predetermined threshold value Fth3.

For example, as shown in FIG. 13, when the charge amount becomes equal to or less than a predetermined threshold Fth3 during the discharge period, if the count value is equal to or greater than t6, the power generation level determination unit 44 may determine that the power generation level is 6. If the count value is equal to or greater than t5 and less than t6, the power generation level determination unit 44 may determine that the power generation level is 5. If the count value is equal to or greater than t4 and less than t5, the power generation level determination unit 44 may determine that the power generation level is 4. If the count value is equal to or greater than t3 and less than t4, the power generation level determination unit 44 may determine that the power generation level is 3. If the count value is equal to or greater than t2 and less than t3, the power generation level determination unit 44 may determine that the power generation level is 2. If the count value is equal to or greater than t1 and less than t2, the power generation level determination unit 44 may determine that the power generation level is 1. If the count value is less than t1, the power generation level determination unit 44 may determine that the power generation level is 0.

Figure 14 shows a flowchart of the process for setting the power generation level corresponding to the upper limit position in the second embodiment.

First, the connection control unit 43 switches each switch so that the solar panel 30 and the capacitor C are connected (see FIG. 10) (step S141). Next, the counting unit 47 starts counting (step S142).

After the counting unit 47 starts counting, if the charge amount of the capacitor C becomes equal to or greater than the predetermined threshold value Fth1 (YES in step S143), the connection control unit 43 switches each switch so that the capacitor C and the discharge resistor Rd are connected (see FIG. 11) (step S144).

When the charge amount of the capacitor C becomes equal to or less than the predetermined threshold value Fth2 (YES in step S145), the setting unit 42 acquires the count value in the count unit 47 (step S146). The setting unit 42 sets the power generation level corresponding to the upper limit position based on the acquired count value (step S147).

Figure 15 is a flowchart showing the power generation level determination process in the second embodiment.

First, the connection control unit 43 switches each switch so that the solar panel 30 and the capacitor C are connected (see FIG. 10) (step S151). Next, the counting unit 47 starts counting (step S152).

When the count value by the counting unit 47 becomes equal to or greater than the predetermined value T0 (YES in step S153), the connection control unit 43 switches each switch so that the capacitor C and the discharge resistor Rd are connected (see FIG. 11) (step S154).

When the charge amount of the capacitor C becomes equal to or less than the predetermined threshold value Fth3 (step S155), the power generation level determination unit 44 acquires the count value in the count unit 47 (step S156). The power generation level determination unit 44 determines the power generation level based on the acquired count value (step S157).

In the second embodiment, an example was described in which the counting unit 47 counts the charge time and discharge time of the capacitor C, but this is not limited thereto, and the counting unit 47 may count either the charge time or the discharge time. For example, if the counting unit 47 counts only the charge time of the capacitor C, it is preferable to set the power generation level corresponding to the upper limit position of the second hand 17 based on the count value, which is the charge time.

In the second embodiment, it is possible to reduce the size of the circuit compared to the configuration of the first embodiment, which includes a detection resistor circuit 45 including multiple detection resistors R. In particular, as shown in FIG. 9, by adopting a configuration in which the capacitance circuit 46 is externally attached to the control circuit 140, it is possible to reduce the size of the control circuit 140.

Next, a first modified example of the second embodiment will be described with reference to FIG. 16. FIG. 16 is a circuit diagram showing a control circuit in the first modified example of the second embodiment. Note that the same reference numerals are used for configurations similar to those described in the second embodiment, and descriptions thereof will be omitted.

16, the capacitance circuit 146 includes a capacitor C1, a capacitor C2, a discharge resistor Rd, and switches SWc11, SWc12, SWc13, SWc14, and SWc15. The capacitors C1 and C2 are arranged to be connectable to the discharge resistor Rd by switching the switches SWc11 to SWc15 using a connection control unit 43 (not shown in FIG. 16).

In addition, capacitors C1 and C2 are connected in parallel. Capacitors C1 and C2 have the same functions as capacitor C described in the second embodiment. That is, capacitors C1 and C2 are used in the process of setting the power generation level corresponding to the upper limit position and in the process of determining the power generation level.

In the first modified example of the second embodiment, when performing the process of setting the power generation level corresponding to the upper limit position and the process of determining the power generation level, only one of the capacitors C1 and C2 may be used, or both may be used. By using both the capacitors C1 and C2, the capacity can be increased. In addition, by discharging either the capacitor C1 or the capacitor C2 while charging the other, the processing time for the process of setting the power generation level corresponding to the upper limit position and the process of determining the power generation level can be shortened.

Specifically, when discharging capacitor C2 while charging capacitor C1, switches SWc11, SWc14, and SWc15 should be connected, and switches SWc12 and SWc13 should be disconnected. Also, when discharging capacitor C1 while charging capacitor C2, switches SWc12, SWc13, and SWc15 should be connected, and switches SWc11 and SWc14 should be disconnected.

Next, a second modified example of the second embodiment will be described with reference to FIG. 17. FIG. 17 is a circuit diagram showing a control circuit in the second modified example of the second embodiment. Note that the same reference numerals are used for configurations similar to those described in the second embodiment, and descriptions thereof will be omitted.

17, the capacitance circuit 246 includes a capacitor C21, a capacitor C22, a discharge resistor Rd, and switches SWc21, SWc22, SWc23, SWc24, SWc25, and SWc2. The capacitors C21 and C22 are connected in series or in parallel to each other by switching the switches SWc21, SWc22, SWc23, SWc24, and SWc25 by the connection control unit 43 (not shown in FIG. 17). The capacitors C21 and C22 are also connected to the discharge resistor Rd.

Capacitor C21 and capacitor C22 have the same function as capacitor C described in the second embodiment. That is, capacitor C21 and capacitor C22 are used in the process of setting the power generation level corresponding to the upper limit position and in the process of determining the power generation level.

In the first modified example of the second embodiment, when performing the process of setting the power generation level corresponding to the upper limit position and the process of determining the power generation level, only one of capacitors C21 and C22 may be used, or both may be used. Furthermore, when using both capacitors C21 and C22, they may be connected in either series or parallel. By connecting capacitors C21 and C22 in parallel, the capacitance can be increased. By connecting capacitors C21 and C22 in series, the capacitance can be reduced and the withstand voltage can be improved.

For example, when only capacitor C21 is used, switches SWc21 and SWc22 are connected, and switches SWc23, SWc24, and SWc25 are disconnected.

When only capacitor C22 is used, switches SWc24 and SWc25 should be connected, and switches SWc21, SWc22, and SWc23 should be disconnected.

When using capacitors C21 and C22 in a series connection, switches SWc21, SWc23, and SWc25 should be in a connected state, and switches SWc22 and SWc24 should be in a non-connected state.

When capacitors C21 and C22 are used in parallel connection, switches SWc21, SWc22, SWc24, and SWc25 should be in a connected state, and switch SWc23 should be in a disconnected state.

In the first and second modified examples of the second embodiment, an example in which two capacitors are provided is shown, but this is not limited thereto, and three or more capacitors may be provided.

Next, the third embodiment will be described with reference to FIG. 18. The basic configuration of the electronic watch 1 of the third embodiment is the same as that shown in FIG. 1. Also, in the third embodiment, as in the first embodiment, the movable range of the second hand 17 when displaying the power generation level is a position indicating 0 to 30 seconds. Note that the same reference numerals are used for the same configuration as that described in the first embodiment, and the description thereof will be omitted.

As shown in FIG. 18, the control circuit 340 includes a plurality of discharge resistors Rd1 to Rdn (n is a natural number of 2 or more) and switches SWc31 to SWc3n (n is a natural number of 2 or more) connected to the plurality of discharge resistors Rd1 to Rdn, respectively.

The multiple discharge resistors may have different resistance values. The connection state of the switches SWc31 to SWc3n is switched by the connection control unit 43 (not shown in FIG. 18). For example, when discharging the charge accumulated in the capacitor C to the discharge resistor Rd1, the switch SWc31 may be in a connected state and the switches SWc32 to SWc3n may be in a disconnected state.

In the third embodiment, the discharge period can be made variable by using one or more of a plurality of discharge resistors having different resistance values.
For example, when the amount of power generation is small and the amount of charge is small, it is advisable to use a discharge resistor with a large resistance value to lengthen the discharge period. This allows the level to be determined with high accuracy even when the amount of charge is small. On the other hand, when the amount of power generation is large and the amount of charge is large, it is advisable to use a discharge resistor with a small resistance value to shorten the discharge period. This allows the time required for level determination to be shortened.

The multiple discharge resistors Rd1 to Rdn may include discharge resistors with the same resistance value. In this case, the connection control unit 43 may switch the connection state of the switches SWc32 to SWc3n so that the combined resistances of the multiple discharge resistors Rd1 to Rdn are different from one another.

In each of the above embodiments and modified examples, an example has been described in which the lower limit position of the movable range of the second hand 17 is 0 seconds and the upper limit position is 30 seconds, but this is not limited to this. Furthermore, the pointer that indicates the power generation level is not limited to the second hand 17.

The above describes the embodiments and their modifications according to the present invention, but the specific configurations shown in these embodiments are shown as examples and are not intended to limit the technical scope of the present invention. Those skilled in the art may modify these disclosed embodiments as appropriate, and it should be understood that the technical scope of the invention disclosed in this specification includes such modifications.

1 Electronic watch, 10 Body, 11 Band fixing part, 12 Button, 13 Crown, 14 Dial, 14a Window, 14b Auxiliary hand, 14c Small window, 15 Hour hand, 16 Minute hand, 17 Second hand, 29, 29a, 29b Switch, 30 Solar panel, 40, 140, 340 Control circuit, 41 Memory unit, 42 Setting unit, 42a Charge amount detection circuit, 43 Connection control unit, 44 Power generation level determination unit, 45 Detection resistance circuit, 46, 146, 246 Capacity circuit, 50 Band display, 60 Secondary battery, 70 Drive mechanism, R Detection resistance, Rt Connection target resistance, Rd Discharge resistance, SWc1, SWc2 Switch, SWt Connection target switch.

Claims (8)

A solar panel that generates electricity by absorbing external light,
a power generation level determination unit that determines a power generation level of the solar panel;
Power generation level display,
a pointer that moves to a position on the power generation level display according to the power generation level;
a setting unit that sets a power generation level corresponding to an upper limit position of the pointer indicating the power generation level display within a range from a lower limit position to an upper limit position;
having
The setting unit is
a power generation level corresponding to the upper limit position is set in accordance with an estimated power generation amount selected from a plurality of estimated power generation amounts estimated in accordance with the individual characteristics of the electronic timepiece;
Electronic clock. a storage unit that stores a table in which each of the power generation levels is associated with a position of the pointer;
the storage unit stores a plurality of the tables corresponding to the plurality of estimated power generation amounts,
the setting unit sets a power generation level corresponding to the upper limit position based on the table corresponding to the expected power generation amount selected by a person operating the electronic timepiece.
2. The electronic watch according to claim 1. The estimated power generation amount is an amount of power generation estimated according to the transmittance of the dial.
3. The electronic watch according to claim 1 or 2. The expected power generation amount is an amount of power generation expected according to the characteristics of the solar panel.
3. The electronic watch according to claim 1 or 2. A plurality of sense resistors;
a connection control unit that sequentially switches an electrical connection state between the solar panel and a connection target resistor that is a part of the plurality of detection resistors;
having
the power generation level determination unit determines the power generation level based on a detection voltage detected in a state in which the solar panel is electrically connected to at least one of the connection target resistors.
5. The electronic watch according to claim 1. The number of the plurality of detection resistors is greater than the number of the power generation levels.
6. The electronic watch according to claim 5. The upper limit position is a position indicating 30 seconds.
The electronic watch according to any one of claims 1 to 6 . the setting unit sets the power generation level corresponding to a position other than the upper limit position based on the power generation level corresponding to the upper limit position set by the setting unit.
The electronic watch according to any one of claims 1 to 7 .

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