HK1083371A - Electronic timepiece with solar cell - Google Patents

Description

Electronic watch with solar cell

Technical Field

The present invention relates to a solar power generation system with a solar power generation function and an electronic timepiece with a solar battery having a back cover and a charging system for charging electric power generated by the solar power generation system.

Background

At present, many electronic watches having a solar cell and utilizing light such as sunlight as a power source for power generation have been commercialized. These electronic watches have a translucent dial beneath which a solar cell is disposed, and therefore have limitations on the design of the dial, and as a result, they have not been able to present a product with a large variety in terms of design.

That is, since the surface of the solar cell is dark brown, in order to cover the color of the surface thereof, it is necessary to put the dial on the solar cell. On the other hand, the solar cell generates electricity by receiving light, and thus requires a certain degree of light transmittance of the dial. Therefore, even if the dial is colored white, the dial is colored gray like ground glass, and the clear white cannot be displayed, which imposes a limitation on the design.

However, in recent years, with the reduction in power consumption of watches, watches can be operated even if the area of the solar cell is reduced to some extent. Therefore, an electronic timepiece with a solar cell has been proposed in which a solar cell is disposed on the outer periphery of a dial in a state substantially perpendicular to the dial. As examples of such conventional devices, japanese utility model No. 62-42390 (patent document 1) and japanese patent application laid-open No. 2002-148366 (patent document 2) have been disclosed, and an electronic timepiece with a solar cell in which a solar cell formed on a flexible strip-shaped printed board is wound around a wall surface of a gap portion between a windshield glass and a dial is disclosed.

Fig. 10 is a cross-sectional view of the solar cell module 1 of the first embodiment shown in fig. 1 of patent document 1, which includes a solar cell module 23 in which a plurality of solar cells 20 are bonded to a printed circuit board 21 and housed in a groove 22a of a support ring 22. The solar cell module 23 is disposed under the flange 26 for fixing the windshield glass 24. A cover portion 22d connecting the inner peripheral ring 22b and the outer peripheral ring 22c is formed at the support ring 22. The solar cell 20 has a structure disposed above the dial 25.

Fig. 11 is a cross-sectional view of embodiment 2 shown in fig. 3 of patent document 1, in which a solar cell component 36 is disposed in a gap portion between a windshield glass 33 and a dial 34 in a state of being wound around an inner wall surface of a backing portion 31 of a case band 35. The solar cell member 36 is formed by bonding a solar cell 30 made of amorphous silicon to a stainless steel sheet 32.

Fig. 12 is a cross-sectional view of example 1 in patent document 2. In this watch, an annular stopper 45 is provided above a position where a dial 43 of a watch movement (watch movement)44 is arranged, and a solar cell 40 is arranged on an inner wall surface 46 of the stopper 45. Further, 41 denotes a windshield glass, and 42 denotes a side flange portion.

However, in the structure of fig. 10, the gap between the windshield glass 24 and the dial 25 has not only the height of the solar cell 20 but also the total height of the flange 26, the cover 22d, and the like. Therefore, the gap between the windshield glass 24 and the dial 25 is widened, and as a result, the position of the dial 25 viewed from the windshield glass 24 becomes deeper, which causes a problem of appearance design called "depth feeling gauge". In addition, since the needle position becomes deep or the needle interval becomes wide, the design becomes poor, and the commercial value is lowered.

In the configuration of fig. 11, the gap between the windshield 33 and the dial 34 is narrowed only by eliminating the flange portion. However, in the performance of the solar cell, it is necessary to widen the width of the cell to a certain extent, to increase the height of the cell, and to widen the gap. Further, since the solar cell 30 is exposed to the gap between the windshield glass 33 and the dial 34, the dark brown color peculiar to the solar cell is directly visible from the outside of the watch 35, and particularly in the case of a bright dial, there is a problem in design that the solar cell 30 looks like an eye-catching black circle.

In the structure of fig. 12, the solar cell 40 is disposed below the flange portion 42 for fixing the windshield glass 41, as in the conventional example shown in fig. 10. Therefore, the gap between the windshield glass 41 and the dial 43 is not only the height of the solar cell 40 but also the total height of the flange 42, and the gap between the windshield glass 41 and the dial 43 is widened. As a result, the dial 43 is positioned deep as viewed from the windshield 41, which causes a problem of appearance design called "depth-thickness gauge".

As described above, in the conventional art, in order to obtain sufficient energy required for driving the timepiece, the solar cell needs a certain area, and even in a man-style timepiece having a large outer diameter, that is, a timepiece having a long solar cell length, when the dial is black, the height of the solar cell is required to be larger than the height of the gap between the windshield glass and the dial of the timepiece not using solar power generation. As a result, there is a problem such as "depth feeling table".

Accordingly, an object of the present invention is to provide a watch in which a dial is not conspicuous and a depth of the dial position is not felt, while ensuring a power generation amount necessary for driving the watch in an electronic watch with a solar cell in which the solar cell is disposed substantially perpendicularly to the dial.

Disclosure of the invention

The electronic watch with solar cell of the invention, it is roughly vertical to the code wheel to dispose the solar cell, in addition, have light guide part in the peripheral portion of the said code wheel, meanwhile, dispose the light-admitting bushing ring on the peripheral portion of the above-mentioned code wheel, and dispose a part of the electricity generating region of the above-mentioned solar cell and a part of the bushing ring covering the electricity generating region of the above-mentioned solar cell under the height of the upper end of the above-mentioned code wheel.

By disposing a translucent grommet and a dial inside the solar cell and providing a light guide portion as a light entrance, light for generating electric power necessary for driving the timepiece can be obtained. Further, by disposing a part of the solar cell power generation region and a part of the dummy ring covering the solar cell power generation region below the level of the top end face of the dial, it is possible to introduce the incident light from the dummy ring to the solar cell disposed below the top end face of the dial. Thus, it is not necessary to dispose the entire solar cell on the upper end face of the dial, and the gap between the lower face of the windshield glass and the upper end face of the dial can be reduced, and the gap can be made the same as that of an electronic timepiece using a primary battery in the past, and the problem of the "deep feeling timepiece" can be solved.

In addition, the present invention is configured such that the thickness of the dial inner side is set to be thicker than the thickness of the peripheral portion.

The thickness of the inner side of the dial on which the pointer is arranged is made thicker than the thickness of the peripheral portion of the dial on which the spacer is arranged, thereby ensuring the area of the light incident surface to the spacer for obtaining the power required for driving the timepiece, and narrowing the gap between the lower surface of the windshield glass and the upper end surface of the dial, thereby eliminating the "feeling of depth".

The light guide portion has an inclined surface portion for reducing the thickness of the dial from the inner side to the peripheral side.

Since the thickness of the dial is thicker on the inner side than on the peripheral side, a difference in the thickness of the dial is generated, and the dial can be made less conspicuous in appearance by providing the inclined surface.

The light guide portion has a stepped portion formed by thinning the dial in a peripheral portion.

The outer peripheral portion of the dial is formed with a high-low slope (staggered layer) which can be easily processed by press working, milling working, or the like, or can be formed by bonding 2 circular plates having different outer diameters.

The present invention is configured such that an inclined surface portion is provided at the spacer ring, and the inclined surface portion covers an inclined surface or a high-low slope-breaking portion of the code wheel light guide portion.

By arranging a spacer for covering a slope or a stepped portion (staggered portion) caused by a difference in thickness between the inner side and the peripheral portion of a dial, a light guide portion for obtaining light for securing a required amount of power to be generated for driving a timepiece can be provided, and the dial is flat in appearance, so that an appearance which is not changed from an electronic timepiece using a primary battery in the past can be realized.

The present invention is configured such that, in the case band of the electronic timepiece with solar cell, a flange portion for fixing the windshield glass in the case band is provided outside the annular protrusion portions of the bushing ring, the solar cell, and the watch movement or the center band holding the solar cell, the bushing ring is disposed directly below the windshield glass, and a cover portion is provided on the bushing ring of the windshield glass and/or the solar cell.

Since the spacer ring can be disposed directly below the windshield glass, the gap between the windshield glass and the upper end face of the dial is reduced by the thickness of the flange portion, and the solar cell is not visible from directly above the windshield glass while the gap is equal to that of an electronic watch using a conventional primary battery.

Therefore, by ensuring the light guide portion of the light incident on the spacer ring and making the thickness of the inner side of the dial thicker than the peripheral portion of the dial, the gap between the lower surface of the windshield glass and the upper end surface of the dial can be reduced, and the design of "deep feeling" can be eliminated.

Brief description of the drawings

Fig. 1 is a sectional view of a main part of an electronic timepiece with a solar cell according to example 1 of embodiment 1 of the present invention.

Fig. 2 is a sectional view of a main part of an electronic timepiece with a solar cell according to embodiment 2 of the present invention.

Fig. 3 is a top view of a solar cell of the present invention.

Fig. 4 is a perspective view showing a state in which the solar cell of the present invention is incorporated in a watch.

Fig. 5 is a plan view of a watch movement (watch movement) of the electronic watch with a solar cell according to the present invention.

Fig. 6 is a graph of light receiving efficiency with respect to dial thickness in example 1 of embodiment 1 of the present invention.

Fig. 7 is a sectional view of a main part of an electronic timepiece with a solar cell according to example 2 of embodiment 1 of the present invention, in which a back ring is changed.

Fig. 8 is a sectional view of the main part of an electronic timepiece with a solar cell in which the shape of a dial is changed according to example 3 of embodiment 1 of the present invention.

Fig. 9 is a sectional view of a main part of an electronic timepiece with a solar cell according to embodiment 1 of the present invention, in which a solar cell is disposed in a middle band.

Fig. 10 is a sectional view of a main part of a related art solar cell-equipped electronic timepiece shown in patent document 1.

Fig. 11 is a sectional view of a main part of a related art solar cell-equipped electronic timepiece shown in patent document 1.

Fig. 12 is a sectional view of a main part of a related art solar cell-equipped electronic timepiece shown in patent document 2.

Best Mode for Carrying Out The Invention

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to this embodiment.

(embodiment 1)

Fig. 1 is a sectional view showing a main part of an electronic timepiece with a solar cell according to embodiment 1 of the present invention, fig. 3 is a plan view of the solar cell according to the embodiment of the present invention, and fig. 4 is a perspective view of a state in which the solar cell according to the embodiment of the present invention is incorporated in a timepiece.

First, the structure of the solar cell will be described with reference to fig. 3. The solar cell 1 is a flexible solar cell having a thin, long, thin, band-like shape that can be housed in a watch case, and is formed by forming an amorphous silicon layer or the like on a PET (polyethylene terephthalate) film as a base substrate, having a thickness of about 150 μm, and bending the amorphous silicon layer as shown in fig. 4.

The solar cell 1 of the present embodiment is a single cell, 1a is a photovoltaic region, 1b and 1c are positive and negative electrodes for extracting generated power, and 1d is a projection having a hole portion for positioning when the solar cell is incorporated into a watch movement (watch movement). The photovoltaic region 1a has an edge portion 1e having a width of about 400 μm over the entire outer circumference thereof and not generating power when exposed to light, which is a cutting margin when a plurality of solar cells are cut and separated from a sheet of PET film into individual solar cells. As shown in fig. 4, the photovoltaic region 1a is formed in a ring shape toward the center of the watch during assembly and is incorporated into the watch.

In the present embodiment, the circuit support base 3 is extended in the vertical direction, and the portion extended upward is further extended to the windshield glass 4 side to form the annular protrusion 3 a. The solar cell 1 is flexible as described above, is wound into a circular ring shape, is fitted into the inner wall surface 3b of the annular protrusion 3a of the circuit support base 3, and is bonded to the inner wall surface 3b of the protrusion 3a in the shape shown in fig. 4 by the tensile force developed by the solar cell itself.

A dial 5(dial plate) is placed on the circuit support base 3 on the front center side from the solar cell 1 arranged in a ring shape, and a light-transmitting liner ring 2(lining ring) is arranged on a peripheral portion 5a of the dial 5, that is, a structure in which the liner ring 2 is arranged inside the solar cell 1 is formed. The dial 5 is not of the same thickness, but the dial inner side 5b of the second hand 11 becomes thicker toward the windshield 4 than the dial peripheral portion 5a on which the liner ring 2 is placed. In addition, a slant portion 5d is formed where a dial thickness becomes thinner from the inner side 5b to the peripheral side 5a, at a high/low slope (staggered slope) connecting the dial peripheral portion 5a and the dial inner side 5 b.

The light guide portion 2a is formed by the step slope (staggered layer) and the slope 5d to ensure a certain width of the light entrance to the liner ring 2. Thus, the required amount of power generation can be ensured, and the dial thickness on the dial inner side 5b can be increased, so that the gap between the windshield glass 4 and the dial 5 can be made equal to the depth of an electronic timepiece using a primary battery in the past.

A part of the photovoltaic region 1a of the solar cell 1 (hatched portion of the solar cell 1 in fig. 1) and a part 2b of the liner ring 2 covering the photovoltaic region 1a of the solar cell 1 are disposed below the position of the dial upper end face 5 c. Thus, the gap from the windshield 4 to the upper surface of the dial peripheral portion 5a on which the spacer 2 is disposed can be narrowed. Further, light that has passed along the grommet 2 as the light guide member is emitted from a portion 2b of the grommet 2, and power generation can be performed even in a portion of the solar cell 1 disposed below the position of the dial upper end face 5 c.

There is an air layer 9 between the liner ring 2 and the solar cell 1, and since part of light passing through the liner ring 2 is reflected and scattered at the interface, it is difficult to see the dark brown color of the solar cell 1 from the outside.

The electrode portions 1b and 1c of the solar cell 1 protrude from the rear cover 10 side through the hole 6a of the watch movement 6, two connection springs 8 are disposed on the rear cover 10 side, and the connection springs 8 are fixed to a circuit board (not shown) by a pressing plate with an insulating sheet interposed therebetween. The tip 8a of the connection spring 8 is in contact with the positive and negative electrodes 1b and 1c of the solar cell, and is configured to guide the electric power generated from the solar cell 1 to the circuit board.

Fig. 5 is a plan view of the watch movement 6 shown in fig. 1 viewed from the rear cover side, and is a schematic plan view showing the arrangement relationship between the 2 connecting springs 8 and the solar cell 1. In order to obtain electrical connection between the solar cell 1 and the circuit board, the connection spring 8 is held fixed by a screw 8b or the like.

(example 1)

Next, the difference in power generation performance between the electronic timepiece with solar cell using the dial 5 having the thickened inner side 5b and the electronic timepiece with solar cell using the flat dial will be described with reference to table 1, fig. 1 and fig. 6.

A typical flat dial thickness a is about 400 μm. On the other hand, in the dial 5 shown in FIG. 1, the dimension D of the peripheral portion 5a of the spacer 2 was set to 300 μm, and the thickness B of the thickened inner side 5B having a 45-degree slope from the inner periphery was set to 700 μm and 1000 μm, and the power generation performance was measured, and the results are shown in Table 1. At this time, the lower end of the power generation region 1a of the solar cell 1 is positioned to extend to the same height as the lower end surface 5e of the dial 5.

TABLE 1

Thickness of dial (B) (mum)	Emitting a current lop (μ A)	Light receiving efficiency (%)*1	Wind-proof glass-code disc gap size (C) (mum)
				400(＝A)	12.7	21.1	2150
700	11.9	19.9	1850
				1000	11.3	18.9	1550

Completed watch assembly status

Illuminance is 500 lux; working voltage is 0.45V

Color of code disc is black

n is 5 average value

^*1: proportion of the obtained current to the emission current of 60 μ A of a flat solar cell

Table 1 shows measured values of the light emission current and light reception efficiency of the watch and a clearance C from the dial of the windshield glass, which were completed when the dial thickness B was changed under the conditions of illumination of 500lux, operating voltage of the solar cell of 0.45V, and black color of the dial.

In addition, the light receiving efficiency described above means: the measured value is an average value of n-5, which is the ratio of the value of the current generated when a single solar cell is placed in a flat state and light is received from the vertical direction with respect to the photovoltaic region to the value of the current generated when light having the same illuminance as that of the solar cell is received from the vertical direction (parallel direction with respect to the solar cell) with respect to the dial in the completed table in which the solar cells are assembled. The collar used for the measurement was made of a colorless transparent polycarbonate resin by injection molding, and had a glossy surface.

As shown in Table 1, the light receiving efficiencies of the dials having the dials with a thickness of 700 μm and 1000 μm, which are formed by increasing the inner side of the dial, are 19.9% and 18.9%, respectively, with respect to the light receiving efficiency of the flat dial with a dial thickness of 400 μm, which is 21.1%.

Fig. 6 is a graph showing the light receiving efficiency with respect to the dial thickness for the data in table 1, and as shown in fig. 6, the light receiving efficiency tends to decrease as the dial thickness increases. This result shows that the thicker the thickness (B) of the dial 5 of fig. 1 is, the narrower the light guide portion 2a of the light becomes, and the light is difficult to enter, which is an inevitable result.

Next, a relationship between the table power consumption and the power generation amount of the solar cell will be described. (about power consumption of watch)

The specification of the electronic timepiece with a solar cell used in the description of the present embodiment is a 3-pin analog timepiece with a calendar, and the power consumption of the timepiece is 0.53 μ a. Therefore, the temperature of the molten metal is controlled,

the power consumption required for daily needle movement is shown as x 24hr, 12.7 μ a hr … … (1) (for power generation quantity)

The specifications of the solar cells used in the table for this example are:

the overall dimension of the solar cell is 92.1mm in length and 2.4mm in width

The effective size of the solar cell light receiving part is 91.3mm long and 1.6mm wide

The effective power generation area is 146mm²(peripheral width ═ about 0.4mm)

1 segment of solar energy

The power generation performance of the solar cell described above was such that the generated current was 60 μ a when the solar cell was placed flat at an illuminance of 500lux and an operating voltage of 0.45V.

The electronic timepiece with a solar cell of the present embodiment employs a 1-stage solar cell, the open circuit voltage Voc of the solar cell is 0.6V, and the generated voltage needs to be increased in order to charge the battery for Li2 times at a rated voltage of 1.35V. If the specification of the boosting system is 3 times of boosting multiplying power and 90% of boosting efficiency, the generated energy of the completion table under the daily average light irradiation condition can be calculated according to the following formula:

power generation amount is irradiation time, light emission current, light reception efficiency, boosting rate and boosting effect

Rate … … (2).

Further, assuming that the average daily illuminance is 500lux and the average irradiation time is 4hr, the table can be maintained if the power generation amount of the completion table under the average daily irradiation condition of the formula (2) is larger than the power consumption amount required for the movement of the needle per day of the formula (1), and the minimum light receiving efficiency can be calculated by the following formula: the meter power consumption is less than or equal to 24hr and the irradiation time is less than or equal to 24hr and the light receiving efficiency is less than or equal to 24hr and the boosting rate is less than or equal to 24hr and less than or equal to 24 hr.

Therefore, the first and second electrodes are formed on the substrate,

minimum light receiving efficiency is meter power consumption × 24hr ÷ irradiation time ÷ emitted current × boosting rate ÷ liter

Pressure efficiency

＝0.53μA×24hr÷4hr÷60μA×3÷90％

＝17.7％

Therefore, the table can be maintained if the light receiving efficiency is 17.7% or more.

Compared with the gap C between the windshield glass and the dial of the traditional 3-pin electronic watch with the primary battery, when the thickness B of the dial is 1000 μm as shown in the table 1, the gap C is 1550 μm as the same as the traditional 3-pin electronic watch with the primary battery, and the light receiving efficiency is 18.9 percent. Therefore, a value larger than the calculated minimum light receiving efficiency value of 17.7% is obtained, the amount of power generation which can be used as a watch is obtained, and the size of the gap between the windshield glass and the dial can be the same as that of a 3-pin electronic watch using a primary battery in the past.

(example 2)

FIG. 7 is a sectional view showing the essential parts of an electronic timepiece with a solar cell according to the invention of example 2. In example 2, compared to fig. 1, the following are set: the inclined surface portion 2c of the light guide portion 2a of the collar 2 projects toward the front center side, and an extension line of the inclined surface portion 2c intersects with an extension line of the thick plate upper end surface 5c of the thick plate portion (B) of the dial 5, so that the inclined surface portion 2c covers the inclined surface 5d of the light guide portion of the dial 5. As shown in fig. 7, since the shape of the collar 2 covering the code wheel inclined surface portion 5d is formed, the area of the light guide portion 2a for guiding light toward the solar cell 1 can be secured while no step (dislocation) is formed between the collar 2 and the code wheel inclined surface portion 5d shown in fig. 1.

(example 3)

Fig. 8 is a sectional view of the main part of an electronic timepiece with a solar cell according to the present invention in example 3. In example 3, compared to fig. 1, the following are set: the inclined surface portion 2c of the light guide portion 2a of the collar 2 projects toward the front center side, and an extension line of the inclined surface portion 2c intersects with an extension line of the thick plate upper end surface 5c of the thick plate portion (B) of the dial 5, so that the inclined surface portion 2c covers the inclined surface 5d of the light guide portion of the dial 5. As shown in fig. 8, if the area of the light guide portion 2a for guiding light toward the solar cell 1 is secured, the dial peripheral portion 5a of the dial 5 and the dial inner side 5b may be connected to each other with a step (staggered layer). The step (staggered layer) formed on the outer periphery of the dial can be formed by press working, milling working, or the like, or can be formed by bonding 2 circular plates having different outer diameters, and has an advantage of being more convenient than the working for forming a slope structure.

(example 4)

Fig. 9 is a sectional view of the main part of an electronic timepiece with a solar cell according to the invention in embodiment 4 of the invention. In examples 1 to 3, the description is given of the structure in which the solar cell 1 is disposed on the annular protrusion 3a for positioning the solar cell 1 provided on the circuit support base 3 as a component of the watch movement 6. The configuration of fig. 9 is: an annular protrusion 50a for positioning a solar cell is provided in a middle band 50 as an exterior component used when the watch movement 6 is housed in the watch case 12, and the solar cell 1 is disposed on an inner wall 50b of the protrusion 50 a. Example 4 can be implemented in the table configuration of example 2.

The middle band is an exterior part for accommodating and holding the watch movement in the watch case or absorbing an impact from the outside of the watch when the watch movement is mounted in the watch case.

(example 5)

In fig. 7, a reflective film made of a thin film such as aluminum is applied by vapor deposition to a surface 2d (a surface indicated by a broken line) of the liner ring 2 not facing the light emitting surface of the solar cell, as a light incident surface for obtaining external light. The reflection film prevents light from leaking from the surface 2d to the outside of the backing ring 2, and thus the amount of light incident on the solar cell 1 can be increased, thereby increasing the amount of power generation.

In fig. 1, 2, 8, and 9, a reflective film may be applied to the liner ring to increase the amount of power generation.

Further, the light receiving efficiency is affected by the color of the dial, and if a white or bright dial which easily reflects the light of the dial is used, the light receiving efficiency increases, and the dial becomes smaller when it is black. In the case where the dial color is black or white, the light receiving efficiency of white is doubled or more.

As described above, according to embodiment 1, in the electronic timepiece with a solar cell in which the solar cell is arranged substantially perpendicularly to the dial, the gap between the lower surface of the wind-proof glass and the upper end surface of the dial can be reduced by arranging the translucent collar inside the solar cell and the part of the collar covering the solar cell power generation region below the height of the upper end surface of the dial, or by ensuring the amount of incident light to the solar cell to obtain the power necessary for driving the timepiece and making the thickness of the dial inside the dial thicker than the thickness of the peripheral portion of the dial on which the collar is mounted, and the gap can be made the same as that of the electronic timepiece using the primary battery in the past, thereby eliminating the "deep feeling".

(embodiment 2)

FIG. 2 is a sectional view of a main part showing embodiment 2 of the present invention, in which a watch movement 6 having a translucent packing 2 attached to the outer periphery of a dial 5 as shown in embodiment 1 is used, but the dial 5 is a flat dial 5 having a uniform thickness of 400 μm. The flange portion 13 for holding and fixing the windshield glass 4 is assembled in the case 12 positioned outside and on the upper surface side of the solar cell 1 and the backing ring 2. The solar cell 1 and the grommet 2 are disposed close to and directly below the windshield glass 4, and a ring-shaped print or the like 4a is applied to the lower surface of the windshield glass 4 at the position where the solar cell 1 and the grommet 2 are disposed.

The flange portion 13 for supporting and fixing the windshield glass 4 in the watch structure shown in fig. 2 is positioned outside the solar cell 1 and the backing ring 2, so that the thickness of the flange portion 26 in the example shown in fig. 10 can be omitted. Thus, the clearance between the windshield 4 and the dial 5 can be 1700 μm, as compared with the clearance of 2150 μm when the dial 5 having a thickness of 400 μm is used as described in embodiment 1. The gap is almost equal to that of the conventional 3-pin electronic watch using a primary battery, and the defect of 'deep feeling' in appearance design can be eliminated.

Further, by applying the ring-shaped print or the metal film 4a to the lower surface of the windshield glass directly above the dummy ring 2 and the solar cell 1, the dummy ring 2, and the like can be shielded from the outside of the case 12, and the appearance quality can be improved.

The light receiving efficiency of the power generation amount shown in the table of embodiment 2 is about 21.1% as in embodiment 1 using a flat dial having a thickness of 400 μm, and a power generation amount more sufficient than that of the table of embodiment 1 can be obtained.

Although the present embodiment has been described using a solar cell having a single ribbon cell, a solar cell such as a 2-segment cell obtained by dividing a solar cell having the same size into 2 right and left parts may be used.

As described above, according to embodiment 2, in the electronic timepiece with a solar cell in which the solar cell is arranged substantially perpendicular to the dial, by arranging the translucent collar inside the solar cell and arranging a part of the solar cell power generation region and a part of the collar covering the solar cell power generation region below the height of the upper end face of the dial, the gap between the lower surface of the windshield glass and the upper end face of the dial can be narrowed, and the gap can be made the same as that of the conventional electronic timepiece using a primary battery, and the design of "deep feeling" can be eliminated.

Industrial applicability of the invention

The invention ensures the light guide part of the light incident on the lining ring, and makes the thickness of the inner side of the dial thicker than the peripheral part of the dial, so the clearance between the lower surface of the wind-proof glass and the upper end surface of the dial can be narrowed, and the invention can provide the electronic watch with the solar cell with the appearance design which eliminates the 'deep and thick feeling'.

Claims (6)

1. An electronic timepiece with a solar cell, wherein the solar cell is disposed substantially perpendicularly to a dial, characterized in that a light guide portion is provided at a peripheral portion of the dial, a translucent collar is disposed at the peripheral portion of the dial, and a portion of a solar cell power generation region and a portion of the collar covering the solar cell power generation region are disposed below a height of an upper end face of the dial.

2. The electronic watch with a solar cell as claimed in claim 1, wherein the thickness of the inner side of said dial is set thicker than the thickness of the peripheral portion.

3. The electronic watch with a solar cell according to claim 1 or 2, wherein said light guide portion has an inclined surface portion which reduces the thickness of said dial from an inner side to a peripheral side.

4. The electronic watch with a solar cell according to claim 1 or 2, wherein said light guide portion has a stepped portion formed by thinning a thickness of said dial at a peripheral portion.

5. The electronic watch with a solar cell according to claim 3 or 4, wherein a slope portion is provided at the collar, and the slope portion covers a slope or a high-low slope portion of the code wheel light guide portion.

6. The electronic timepiece with solar cell according to claim 1, wherein a flange portion for fixing a wind-proof glass in the case is provided in the case of the electronic timepiece with solar cell outside the annular protrusion of the bushing ring, the solar cell, and the watch movement or the center band holding the solar cell, the bushing ring is disposed directly below the wind-proof glass, and a cover portion is provided on an upper portion of the bushing ring of the wind-proof glass and/or the solar cell.