JP2009122126A - Electronic timepiece with solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem with an electronic timepiece having a solar cell having flexibility for arranging it substantially perpendicular to the dial on the outer periphery of the movement of the electronic timepiece to supply electric power to the electronic timepiece, wherein, when the solar cell is divided into a plurality of photovoltaic power generation cells in the long side direction and they are connected in series, and the electronic timepiece is put on an arm, it is partially shaded by clothes, an photovoltaic power generation cell which does not contribute to power generation occurs, and sufficient charge is not obtained. <P>SOLUTION: An photovoltaic power generation cell of the solar cell is equally divided into two parts in the long side direction, one of the two divided photovoltaic power generation cells is arranged in the 12:00 direction, the other is arranged in the 6:00 direction, and both divided photovoltaic power generation cells are interconnected electrically. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention provides a solar cell-equipped electronic device in which a solar cell is disposed in a turning portion of a timepiece having a solar power generation system that generates power using light and a charging system that charges electric power generated by the solar power generation system. The present invention relates to a clock structure of a clock.

Conventionally, there are many electronic watches having a solar cell and using light such as sunlight as an energy source. In many of these electronic watches, the solar cell is disposed on the lower surface of the dial, so that the light used for power generation must pass through the windshield and further pass through the dial to reach the solar cell. For this reason, the dial is required to have optical transparency. Therefore, the design of the dial plate is restricted, and product proposals with abundant variations that become part of the user's fashion could not be made.

In other words, the surface of the solar cell is dark brown, and it is not a beautiful color, so it is necessary to place a dial on the top surface of the solar cell to hide the surface color, but for photovoltaic power generation The dial must be light transmissive. For this reason, the metal plate cannot be used, there are many blurred colors such as frosted glass, and there is a problem regarding the diversity of design that a vividly colored dial cannot be used.

By the way, in recent years, power consumption of a timepiece has been reduced, and the timepiece can be driven even if the area of the solar cell is reduced to some extent. In view of this, an electronic timepiece with a solar cell in which a solar cell is disposed on the outer periphery of the dial substantially perpendicular to the dial has been proposed. As this conventional example, a solar cell formed on a flexible elongated band-shaped film substrate is provided with a ring-shaped bank above the dial surface of the watch movement and along the outer periphery of the watch movement, Some solar cells are arranged on the inner surface of the ring-shaped bank. (For example, see Patent Document 1)

JP 2002-148366 A (page 3-4, FIG. 1-2, FIG. 4-5)

In the first embodiment of Patent Document 1, a single-cell solar cell is used, and the generated voltage from the solar cell is boosted by a combination with a booster circuit provided on the watch circuit board of the watch movement. The voltage for driving the watch movement and charging the secondary battery is secured.

Moreover, in 2nd Embodiment of the said patent document 1, a required voltage is ensured by connecting three rectangular photovoltaic power generation cells elongated in the long side direction of a solar cell in series.

Furthermore, in the third embodiment of Patent Document 1, two independent photovoltaic cells in which extraction electrodes are arranged at both ends of each photovoltaic cell divided into two in the long side direction of the solar cell are used, and a voltage detection circuit is used. The voltage of the secondary battery is detected, and the photovoltaic cells are connected in series or in parallel according to the voltage. At the time of parallel connection, the voltage is boosted by a booster circuit to ensure a required voltage.

However, in the first embodiment of Patent Document 1, a booster circuit is indispensable because the voltage obtained by power generation is low because the solar cell is a single cell, but the solar cell has a loss in the booster circuit. There is a problem that the electric power generated in the above cannot be efficiently used for timepiece driving, and a space for the booster circuit must be secured.

  Therefore, it is conceivable that the booster circuit is unnecessary by dividing the power generation unit of the solar cell into a plurality of (for example, two) photovoltaic cells in the long side direction and connecting them in series.
However, when an electronic timepiece equipped with such a solar cell is worn on the wrist, it is partially shielded from light by clothing, resulting in a photovoltaic cell that does not contribute to power generation, making it impossible to charge well.

SUMMARY OF THE INVENTION An object of the present invention is to provide a timepiece structure that solves the above problems and can efficiently generate stable power even when the timepiece is carried, in an electronic timepiece with a solar cell in which solar cells are arranged substantially perpendicular to the dial. It is.

In order to achieve the above object, the gist of the present invention is an electronic timepiece with a solar cell in which a belt-like solar cell is arranged substantially perpendicular to a dial plate.
The photovoltaic cell of the solar cell is equally divided into two in the long side direction,
One of the two divided photovoltaic cells is arranged at 12 o'clock and the other at 6 o'clock.
Both split photovoltaic cells are electrically connected .

  With this arrangement, even if the watch is hidden behind the sleeve when worn, each photovoltaic cell is exposed to light in an almost equal area, and the difference in the generated voltage between the photovoltaic cells is kept small and efficient. Power generation is possible.

The dividing boundary line of the photovoltaic cell is in the 3 o'clock direction or 9 o'clock direction of the dial,
The solar cell is arranged .

By arranging the dividing boundary line in the 3 o'clock direction or 9 o'clock direction of the dial, the light receiving areas of the divided photovoltaic cells when hidden behind the sleeve can be made substantially equal.

The photovoltaic cell pattern of the solar cell, which is substantially equally divided into two in the long side direction,
It is characterized by being formed in a comb-teeth shape alternately from both sides in the short side direction and in an equal area .

By dividing the photovoltaic cell divided into two in the long side direction into a comb-like shape, the amount of power generation in the short knitting direction can be made uniform, and more efficient charging is possible.

The divided four-stage photovoltaic cells are connected in series .
By dividing into two equal parts in the long side direction, a voltage about four times that of a single photovoltaic cell can be obtained, so that a voltage suitable for charging a secondary battery generally used for clock driving can be secured. .

As described above, by implementing the present invention, even when the arm is worn and hidden behind the sleeve, the split photovoltaic cell can receive light evenly.

It is a top view of the solar cell of 1st Embodiment of this invention. It is sectional drawing of the electronic timepiece with a solar cell which shows one embodiment of this invention. It is the elements on larger scale of FIG. It is a usage example of the electronic timepiece with solar cell of the fourth embodiment of the present invention. It is a top view of the solar cell of 2nd Embodiment of this invention. It is a top view of the solar cell of 3rd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view of a solar cell 1 according to the present invention. An elongated belt-shaped power generation region 20 and extraction electrodes 3a and 3b for taking out the power generated by the solar cell 1 are arranged at both ends of the power generation region 20.

Further, the power generation region 20 has a comb-teeth shape alternately opposed from the short side direction 9 of the solar cell 1, and the area divided right and left by the boundary line 2 e at the center of the long side direction 8 of the solar cell 1 is equal 4 One photovoltaic cell 2 is arranged.

The sectional structure (not shown) of the solar cell 1 is obtained by laminating a transparent electrode layer, an amorphous silicone layer, a metal thin film layer, and a protective printing layer (not shown) on a base substrate 4 made of a thin resin film. The power generation cell 2 is configured, and the transparent electrode layer and the metal thin film layer sandwiching the amorphous silicone layer serve as positive and negative electrodes of each photovoltaic cell.

The solar cell 1 is flexible because it is formed on a thin resin film.

FIG. 3 is an enlarged view of a part of FIG. 1, and each photovoltaic cell 2 is formed in a comb-teeth shape alternately opposed from both sides in the short side direction. In other words, since the teeth 2a of the combs facing each other are arranged so as to be inserted into the space 2b between the teeth of the other comb, the photovoltaic cell 2c arranged mainly at the lower part is equivalent to the teeth of the comb. The area of the upper part of the photovoltaic cell 2d extends to the lower part, whereas the upper part of the photovoltaic cell 2d extends to the lower part. Therefore, the difference in power generation efficiency between the upper and lower photovoltaic cells can be eliminated.

Also, the electrical connection structure between each photovoltaic cell 2 of the solar cell 1 and the extraction electrodes 3a and 3b will be described with reference to FIG. 3. The extraction electrode 3a and the positive electrode (not shown) of the photovoltaic cell 2c Are connected by the carbon wiring 5a, and the negative electrode (not shown) of the photovoltaic cell 2c and the positive electrode of the photovoltaic cell 2d adjacent to the upper part are connected by the carbon wiring 5b. Further, the negative electrode (not shown) of the photovoltaic cell 2d and the positive electrode (not shown) of the photovoltaic cell 2g adjacent in the long side direction 8 are connected by the carbon wiring 5c. Further, similarly to the connection between 2c and 2d, 2c and 3a, connection is also made between photovoltaic cells 2h, 2h and 3b adjacent to 2g and the lower part. With this connection, one extraction electrode 3a is electrically connected in series from all the photovoltaic cells 2 to the other extraction electrode 3b. This connection method is common to the solar cells of all the embodiments.

The solar cell 1 requires a gap between the photovoltaic cells 2, that is, a width of the insulating region 2 f of at least about 400 μm for insulation by the conventional method using laser patterning and a screen. If the space between the photovoltaic cells 2 is complicated, a large area is taken up by the insulating region 2f, the area of the photovoltaic cell 2 itself becomes small, and the amount of power generation cannot be secured. In the invention, since the solar cell 1 is formed using photolithography, the width of the insulating region 2f is about 50 μm, and even if the shape of the insulating region becomes complicated, the necessary area of the power generation region can be secured. it can.

Next, a timepiece structure using the solar cell according to the present invention will be described.

FIG. 2 is a cross-sectional view of an electronic timepiece with a solar cell. In the timepiece movement 10, a timepiece driving wheel train (not shown) for driving the timepiece hands 17a, 17b, and 17c, a circuit board, and a secondary battery for storing generated electric power. Etc. are built-in.

A solar support ring portion 12 is provided in a ring shape on the outer peripheral portion of the timepiece movement 10. The solar support ring portion 12 is one of the parts constituting the timepiece movement 10, and is integrated with the timepiece movement 10 at a portion not shown.

Moreover, the flexible solar cell 1 is arranged in a ring shape on the inner wall surface 12a of the solar support ring portion 12, and the solar cell 1 sticks to the inner wall surface 12a with a force of spreading. It is what.

Reference numeral 15 denotes a connection spring for electrically connecting the driving circuit built in the timepiece movement 10 and the solar cell 1, and two springs are arranged so as to contact with the extraction electrodes 3 a and 3 b of the solar cell 1 independently. ing.

13 is a turn ring disposed inside the solar cell 1 so as to cover the solar cell 1 and is made of a light-transmitting material.

Reference numeral 11 denotes a dial, which does not have to be a light-transmitting dial used in an electronic timepiece with a solar cell having a structure in which a solar cell is arranged below the dial, and an electronic timepiece using a primary battery or a mechanical type. A metal dial used in a watch may be used.

Next, the power generation operation in the timepiece using the solar cell according to the present invention will be described.

In FIG. 2, when light as indicated by an arrow A enters, the light transmitted through the windshield 16 is reflected by the surface 11 a of the dial plate 11, and part of the light is again reflected by the lower surface 16 a of the windshield 16, so that the turn ring 13. to go into. When light enters the turn ring 13, the light passes through the turn ring 13, and light enters the photovoltaic cell 2 of the solar cell 1 to generate a current and a voltage corresponding to the amount of light.

Here, the voltage generated by one photovoltaic cell 2 is about 0.6V. When a secondary battery having a rated voltage of about 1.5V is used, the photovoltaic cell shown in FIG. By using solar cells connected in series, it is possible to secure a voltage that can charge the secondary battery directly without going through the booster circuit.

As a second embodiment, the photovoltaic cell 2 can be used without being divided in the long side direction as shown in FIG. However, since the generated voltage is small, a booster circuit is required to secure a general clock driving voltage.

In addition, as a third embodiment, for example, a watch movement that is multifunctional and consumes a large amount of power may be designed to be driven at 3V. In this case, as shown in FIG. 6, the photovoltaic cell 2 is divided into three equal parts in the long side direction 8 and is connected in six stages in series, so that a predetermined voltage can be secured. Similarly, the booster circuit becomes unnecessary by equally dividing the photovoltaic cell 2 in the long side direction 8 according to the required voltage of the type of the watch movement.

By the way, for example, the photovoltaic cell 2 is divided into three equal parts in the long side direction 8, and the upper and lower three stages are connected in series, and the upper and lower parts are connected in parallel between the extraction electrodes 3a and 3b. In the case of a watch movement using a rechargeable battery with a rated voltage of 1.5 V, a booster circuit is not required. A difference in output occurs, and stable power generation cannot be expected.

Next, as a fourth embodiment, the influence of a sleeve when carrying a watch using a solar cell in which the photovoltaic cell of the present invention is divided into two equal parts in the long side direction will be described with reference to FIG.

First, the relative position of the solar cell 1 with respect to the watch case 14 when the solar cell 1 is assembled into the watch case 14 is such that the boundary line 2e that equally divides the power generation region 20 into two in the long side direction 8 is 3 o'clock of the watch case 14. Alternatively, it is incorporated in the 9 o'clock direction. That is, each photovoltaic cell 2 is arranged in a range from 3 o'clock to 12 o'clock and 9 o'clock, or from 3 o'clock to 6 o'clock and 9 o'clock.

By incorporating the solar cell 1 into the watch case 14 as described above, even if the watch 40 is attached to the arm 50 and partially shielded from light by the clothing 51 as shown in FIG. The light hits almost the same area, and the power generation voltage difference between the photovoltaic cells is kept small, enabling efficient power generation.

DESCRIPTION OF SYMBOLS 1 Solar cell 2 Photovoltaic cell 2e Boundary line 2f Insulation area | region 3a, 3b Extraction electrode 10 Timepiece movement 11 Dial 12 Solar support ring part 13 Turning ring 20 Power generation area 40 Electronic timepiece with solar cell

Claims (4)

In an electronic watch with a solar cell in which a belt-shaped solar cell is arranged substantially perpendicular to the dial,
The photovoltaic cell of the solar cell is equally divided into two in the long side direction,
One of the two divided photovoltaic cells is arranged at 12 o'clock and the other at 6 o'clock.
An electronic timepiece with a solar cell, wherein both split photovoltaic cells are electrically connected . The dividing boundary line of the photovoltaic cell is in the 3 o'clock direction or 9 o'clock direction of the dial,
The solar cell-equipped electronic timepiece according to claim 1, wherein the solar cell is disposed . The photovoltaic cell pattern of the solar cell, which is substantially equally divided into two in the long side direction,
The electronic timepiece with solar cell according to claim 1, wherein the electronic timepiece is provided with a comb-teeth shape alternately from both sides in a short side direction and has an equal area . 4. An electronic timepiece with a solar cell according to claim 3, wherein the divided four-stage photovoltaic cells are connected in series.

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