JP4834172B2 - Electronic watch with solar cell - Google Patents

Description

  The present invention relates to the structure of an electronic timepiece with a solar cell.

Conventionally, in many electronic timepieces with solar cells, the solar cell is arranged on the lower surface of the dial, so that the light energy for power generation passes through the windshield, and further the energy that has passed through the dial is used for power generation of the solar cell. . For this reason, the dial plate is required to have a light transmission characteristic that exceeds a predetermined level. Therefore, it has been impossible to use a conventional metal dial.

As a conventional technique for solving this problem, Japanese Utility Model Publication No. 62-42390 proposes that a solar cell is arranged in a ring shape on the inner wall surface of the outer case of the gap partly sandwiched between the lower surface of the windshield glass of the watch and the dial. Has been. According to this proposal, a solar cell block formed by mounting a solar cell on a flexible printed board is arranged on the inner wall surface of the outer case. In Japanese Utility Model Laid-Open No. 58-26696, a solar cell is formed on a decorative ring arranged on the outer periphery under the windshield glass of a watch.
Looking at the contents of the above two proposals, there are a proposal that a plurality of solar cells are mounted in series every 30 degrees and a proposal that a plurality of amorphous silicon layers are formed.

Japanese Utility Model Publication No. 62-42390 Shokai 58-26696

However, in the above two proposals, since the solar cell is not directly attached to the watch movement and connected to the watch circuit, the power generation performance cannot be confirmed by the watch movement alone, and the dial and the solar cell block are attached to the watch movement. After installation, functional tests such as power generation performance are required. It becomes difficult to prepare a timepiece movement for which performance inspection has been completed and to cope with the conventional timepiece production of various dials.

In addition, when multiple solar cells are arranged on the inner wall surface of the outer case, for example, when four cells are arranged every 90 degrees, when light enters obliquely, the light is blocked by the outer case, and the solar cell that is shaded Obviously, no light is input and it is extremely less than other solar cells. When a plurality of solar cells are connected in series, it is obvious that the smallest current among them is the current value generated at that time of the solar cell block. Therefore, the influence on the generated current increases depending on the incident angle.
The present invention solves the above-mentioned problems, makes it possible to reliably confirm the power generation performance in the completed state of the watch movement, and to support various kinds of dials, and to maintain uniform power generation even when the watch is carried. With the goal.

To achieve the above object, the present invention provides:
A secondary battery as a power source;
A voltage detection circuit for detecting the voltage of the secondary battery;
A solar cell body for charging the secondary battery,
When the voltage detection circuit detects a predetermined voltage or less, it outputs a stop signal,
When it detects more than a predetermined voltage, it outputs a normal status signal,
The solar cell body is composed of a plurality of solar cells,
At the time of outputting the stop signal, the plurality of solar cells are connected in series,
The plurality of solar cells can be switched to a parallel connection when the normal state signal is output .
In addition, an oscillation circuit using the secondary battery as a power source,
The oscillation circuit is stopped by the stop signal, and the plurality of solar cells are connected in series .

As described above, in the present invention,
When stopping, increase the output voltage by connecting multiple solar cells in series, making it easier to start the oscillation circuit,
In a normal state, a plurality of solar cells are switched to a parallel connection so that a large amount of current can be obtained. Therefore, with a simple configuration, the mobility at the time of oscillation and the increase in the amount of generated power at the time of normal use can be paralleled.

It is sectional drawing of the electronic timepiece with solar cell of 1st embodiment of this invention. It is a top view of the solar cell body of a first embodiment. 1 is a system configuration diagram of a solar cell-equipped electronic timepiece according to the present invention. It is a top view of the solar cell body of a second embodiment. It is a top view of the solar cell body of a third embodiment. It is a system diagram of the timepiece using the solar cell body of the third embodiment.

Embodiments of an electronic timepiece with solar cell according to the present invention will be described below. FIG. 1 is a cross-sectional view of an electronic timepiece with a solar cell according to the present embodiment. FIG. 2 is a plan view of the solar cell body 1 of the first embodiment. FIG. 3 is a system configuration diagram of the electronic timepiece with solar cell according to the present embodiment. FIG. 4 is a plan view of the solar cell body 20 of the second embodiment. FIG. 5 is a plan view of the solar cell body 40 of the third embodiment. FIG. 6 is a system diagram of a timepiece using the solar cell body 40 of the third embodiment.
In FIG. 1, 1 is a solar cell body. First, the shape of the solar cell body 1 will be described with reference to FIG. 2. Reference numeral 2 denotes a film substrate serving as a substrate for the solar cell body 1. A thin metal electrode film (not shown) is formed on the upper surface of the film substrate 2. Reference numeral 3 denotes an amorphous silicon solar cell formed on the upper surface of the metal film formed on the film substrate 2 described above. A metal transparent electrode film is formed on the upper surface of the solar cell 3 (not shown). Reference numerals 4A and 4B denote take-out electrodes for externally connecting the metal electrode film and the transparent electrode film formed on the upper and lower surfaces of the solar cell 3, respectively.

Returning to FIG. 1, reference numeral 5 denotes a timepiece movement. The timepiece movement 5 incorporates a driving circuit 11 for driving the timepiece described in FIG. 3, a secondary battery 12, a pointer wheel train 14 for moving the hand, a step-up charging circuit 10, and the like. 5A is a solar support ring portion provided in a ring shape on the outer peripheral portion of the timepiece movement 5. The solar support ring portion 5 </ b> A is one part that constitutes the timepiece movement 5. Further, a solar cell body 1 shown in FIG. 2 is arranged on the inner wall surface of the solar support ring portion 5A as shown.
Reference numeral 6 denotes a connection spring for connecting the driving circuit built in the timepiece movement 5 and the solar cell body 1. The connection spring 6 is in contact with the extraction electrodes 4A and 4B of the solar cell body 1 independently.

  A reference ring 7 is arranged inside the solar cell body 1 so as to cover the solar cell body 1. The dial ring 7 is made of a material having light permeability.

  Reference numeral 8 denotes a dial which is usually used for a timepiece. The dial 8 may be a metal, and the outer diameter is smaller than the planar arrangement of the solar cell body 1 as shown. 9 is a windshield glass of a normal timepiece.

  Next, referring to FIG. 3, a system configuration of the electronic timepiece with solar cell according to the present embodiment will be described. Reference numeral 3 denotes a solar cell 3 in FIG. Reference numeral 10 denotes a boosting charging circuit for boosting and charging the power generation voltage of the solar cell 3. Reference numeral 11 denotes a drive circuit that performs timekeeping of the timepiece and driving of the pointer wheel train 14. Reference numeral 12 denotes a secondary battery that charges the output of the boost charging circuit 10 and serves as a power source for the drive circuit 11. Reference numeral 13 denotes a connection portion showing the extraction electrodes 4A and 4B and the connection spring 6 of the solar cell body 1 described in FIG. Reference numeral 14 denotes a pointer wheel train.

Next, the operation in the present invention will be described.
In FIG. 1, when light as indicated by an arrow A enters, the light transmitted through the windshield 9 is reflected by the surface of the dial plate 8, and part of the light is reflected again by the lower surface of the windshield 9 and enters the turn ring 7. When the light enters the turn ring 7, the light passes through the turn ring 7 and enters the solar cell 3 of the solar cell body 1. The operation of this side is apparent from the drawings.
Next, in FIG. 3, the solar cell 3 generates a current and a voltage corresponding to the amount of input light. Here, the voltage generated by one solar cell 3 is 0.6V to 1.0V. The voltage of the secondary battery 12 used in the timepiece is generally about 1.5V. That is, the watch system is configured with a 1.5V system. Therefore, the power generated by the solar cell 3 is input to the boosting charging circuit 10 to boost the voltage to a voltage effective for charging the secondary battery 12. The output of the step-up charging circuit 10 charges the secondary battery 12. The drive circuit 11 and the pointer wheel train 14 are driven using the secondary battery 12 as a power source. The operation of the entire watch system can be confirmed in a state in which the dial 8 and the dial ring 7 are not assembled, that is, in the state of the watch movement.

  After confirming the operation as a timepiece movement, as shown in FIG. 1, the dial plate 8, the dial ring 7, the hands, etc. can be assembled into the assembled outer case.

  Therefore, the outer diameter of the dial 8 needs to be smaller than the diameter where the solar cell body 1 is arranged. In addition, the turn ring 7 has not only good light transmittance, but the light transmittance is selected so that the color of the solar cell body 1 cannot be seen through the windshield 9 aesthetically.

  As shown in FIG. 1, incident light is from the arrow A and from the arrow B. As for the arrow A, it is clear that light enters the surface of the solar cell 3 on the drawing side and contributes to power generation. However, the arrow B does not enter the surface of the solar cell 3 in the drawing and does not contribute to power generation, and enters the surface of the solar cell 3 on the opposite side not shown in the drawing to contribute to power generation. Therefore, the shape of the single solar cell 1 shown in FIG. 2 is very effective.

  FIG. 4 is a second embodiment of the solar cell body 1 shown in FIG. In the first embodiment shown in FIG. 2, the solar cell body 1 is composed of a single solar cell, but the solar cell body 20 of FIG. 4 is composed of three solar cells 31, 32, and 33. In the solar cell body 20, the solar cells 31, 32 and 33 are connected in series between the extraction electrodes 4A and 4B. Therefore, when the same amount of light is irradiated, a voltage about three times as large is generated, and the amount of current generated is proportional to the area, so that it is 1/3 or less.

  When this solar cell body 20 is used, in the timepiece system described with reference to FIG. 3, the booster circuit function is unnecessary among the functions of the booster charging circuit 10. As shown in FIG. 4, in the solar cell body 20, by arranging the solar cells 31, 32, 33 in a shape in which horizontally long shapes are arranged vertically, either the arrow B or the arrow A is used as described in the first embodiment. Even if light is input from a direction, the solar cells 31, 32, 33 are irradiated with light that is uniform to some extent.

  FIG. 5 is a third embodiment of the solar cell body 40. In the solar cell body 40 of FIG. 5, 35 and 36 are solar cells. Reference numerals 4C, 4D, 4E, and 4F are extraction electrodes for the solar cells 35 and 36, respectively. The solar cell 35 can be connected to an external circuit by the extraction electrodes 4F and 4D, and the solar cell 36 can be connected by the extraction electrodes 4C and 4E. It is a configuration. That is, the solar cell body 40 of the third embodiment has two independent solar cells 35 and 36 arranged therein.

  FIG. 6 is a system diagram of a timepiece using the solar cell body 40 shown in FIG. Reference numeral 40 denotes the solar cell body 40 described in FIG. Accordingly, similarly, reference numeral 35 denotes a first solar cell 35, and 36 denotes a second solar cell 36. 4C and 4E are electrodes of the solar cell 35, and 4D and 4F are electrodes of the solar cell 36. Reference numeral 50 denotes a switching circuit for switching the connection method of the electrodes 4C, 4D, 4E, and 4F of the four solar cell bodies 1. The switching circuit 50 includes a first switch 50A and a second switch 50B that move in the same manner as shown, and a third switch 50C and a fourth switch 50D that move in the opposite direction. The third switch 50C and the fourth switch 50D are configured to close when the entire circuit system is not operating.

  51 is an oscillation circuit that outputs a reference signal, 52 is a timing circuit that counts the reference signal and counts the clock, and 53 is a drive circuit that drives the indicator wheel train 14 described with reference to FIG. is there. Reference numeral 54 denotes a secondary battery, and reference numeral 55 denotes a voltage detection circuit for detecting the voltage of the secondary battery 55. The voltage detection circuit 55 measures the voltage of the secondary battery 54, and detects the stop signal ST when detecting that the voltage is lower than the predetermined voltage, and the normal state signal DR when detecting that the voltage is higher than the predetermined voltage. Output.

  Reference numeral 56 denotes a boosting charging circuit that boosts and outputs the voltage of the input power when the normal state signal DR is input. As a result, the amount of current decreases in inverse proportion. Here, the boosting charging circuit 56 will be described as a circuit configuration that triples the voltage.

  Next, the operation of the third embodiment will be described with reference to FIG. First, in a state where the voltage of the secondary battery 54 is higher than a predetermined voltage, the voltage detection circuit 55 outputs a normal state signal DR. In the switching circuit 50 that receives the normal state signal DR, the first switch 50A and the second switch 50B are closed, and the third switch 50C and the fourth switch 50D are opened. As a result, the first solar cell 35 and the second solar cell 36 of the solar cell body 1 are connected in parallel. In this parallel connection state, the same state as that of the single solar cell 3 described with reference to FIGS. 1 and 2 is obtained. That is, the generated voltage is about 0.6 V, which is the same as the case of one sheet, but the current value is almost the sum of the first solar cell 35 and the second solar cell 36.

At this time, the electric power generated by the solar cell body 40 is input to the step-up charging circuit 56 and 3
The voltage is doubled and boosted to about 1.8 V to charge the secondary battery 54. The oscillation circuit 51, the clock circuit 52, and the drive circuit 53 are driven using the charged voltage of the secondary battery 54 as a power source. The oscillation circuit 51, the timing circuit 52, the drive circuit 53, and the pointer wheel train 14
Is substantially the same as that described in FIG.

  When the watch is placed in a dark place, the voltage of the secondary battery 54 decreases. When the voltage is equal to or lower than the predetermined voltage, the voltage detection circuit 55 stops outputting the normal state signal DR and outputs a stop signal ST. As a result, the first switch 50A and the second switch 50B of the switch circuit 50 are opened, and the third switch 50C and the fourth switch 50D are closed. Further, the oscillation circuit 51 is stopped by the stop signal ST. Thereby, all the operations are stopped.

  At this time, the two solar cells 35 and 36 of the solar cell body 40 are connected in series. In this state, when the solar cell body 40 is irradiated with light, the voltage generated by the solar cell body 40 is about twice as high as 1.2V. This voltage is applied to the oscillation circuit 51 through the fourth switch 50D of the switch circuit 50. The oscillation circuit 51 starts oscillation by the voltage of about 1.2V.

  Further, the boost charging circuit 56 starts the boost charging operation by the output of the oscillation circuit 51. When this state continues, the secondary battery 54 is charged. When the voltage of the secondary battery 54 becomes equal to or higher than a predetermined voltage, the voltage detection circuit 55 starts outputting the normal state signal DR and stops outputting the stop signal ST. As described above, the two solar cells 35 and 36 of the solar cell body 40 are connected in parallel.

  In the third embodiment, the solar cells 35 and 36 are arranged so as to bisect the outer peripheral portion of the timepiece movement and the inner wall surface of the solar support ring portion 5A shown in FIG. 1, but only at the start of oscillation. In a normal state, it is possible to obtain the same incident light as in the above embodiments.

DESCRIPTION OF SYMBOLS 1 Solar cell body 3 Solar cell 5 Watch movement 7 Turn-around ring 8 Dial 10 Boosting charge circuit

Claims (6)

A secondary battery as a power source;
A voltage detection circuit for detecting the voltage of the secondary battery;
A solar cell body for charging the secondary battery,
When the voltage detection circuit detects a predetermined voltage or less, it outputs a stop signal,
When it detects more than a predetermined voltage, it outputs a normal status signal,
The solar cell body is composed of a plurality of solar cells,
At the time of outputting the stop signal, the plurality of solar cells are connected in series,
When outputting the normal state signal, the plurality of solar cells can be switched to parallel connection.
An electronic watch with a solar cell. An oscillation circuit using the secondary battery as a power source;
The oscillation circuit is stopped by the stop signal, and the plurality of solar cells are connected in series.
The electronic timepiece with solar cell according to claim 1. Operates when the normal state signal is output,
A step-up charging circuit for boosting electric power generated by the solar cell body and charging the secondary battery;
The electronic timepiece with a solar cell according to claim 1, wherein the electronic timepiece has a solar cell. The solar cell body is disposed substantially perpendicular to the surface of the dial.
The electronic timepiece with solar cell according to claim 1, wherein the electronic timepiece has a solar cell. A solar support ring that is disposed on the outer periphery of the watch movement and constitutes the watch movement;
By arranging the solar cell body on the inner surface of the solar support ring,
The solar cell body is disposed substantially perpendicular to the surface of the dial.
The electronic timepiece with solar cell according to claim 4. The plurality of solar cells are divided so as to be arranged in the long side direction.
The electronic timepiece with solar cell according to claim 4, wherein the electronic timepiece has a solar cell.

Images