Electronic clock

Abstract

To provide an electronic timepiece which can attain an effective power generation, an effective light emission, and downsizing at one time.SOLUTION: An electronic timepiece has a solar battery (70) including: a wire electrode (71) and a lower electrode (73) as a pair of electrodes; and a power generation layer (72) between the pair of electrodes, the power generation layer (72) including a compound semiconductor material which can emit light by applying a voltage to the pair of electrodes. The electronic timepiece has a plurality of solar batteries (70) and the solar batteries may be connected in series. Each of wire electrodes (71) of the pair of electrodes on the side where light enters may have the same contact area with the power generation layer (72).SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This invention relates to an electronic clock.

Background Art

[0002] Some electronic clocks operate on power generated by a solar cell. During the day or when used under indoor lighting, the electronic clock can efficiently generate electricity with this solar cell and charge a secondary battery. On the other hand, in order to improve the visibility of the display during use at night and the like, the electronic clock has a light-emitting part that illuminates the display surface. Patent Document 1 discloses a technique for improving the production yield in an electronic clock provided with a solar panel and a light-emitting part using an EL (Electro-Luminescent) panel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in order to coexist a solar cell that receives light and a light-emitting part that emits light in a narrow range, a mounting space is required, and there is a problem that it is difficult to achieve both effective power generation and light emission and miniaturization.

[0005] An object of this invention is to provide an electronic clock capable of achieving both effective power generation and light emission and miniaturization.

Means for Solving the Problems

[0006] To achieve the above object, this invention provides a pair of electrodes, a power generation layer sandwiched between the pair of electrodes and containing a compound semiconductor material capable of emitting light by applying a voltage to the pair of electrodes, having , including an arc shape equipped with a solar cell 、 Of the pair of electrodes, the first electrode on the side where light is incident is a linear electrode extending along the outer edge of the arc shape is an electronic timepiece.

Advantages of the Invention

[0007] According to the present invention, in an electronic timepiece, there is an effect that effective power generation and light emission can be achieved while achieving miniaturization.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [First Embodiment] FIG. 1 is a front view of an electronic timepiece 1 of the first embodiment.

[0010] The electronic timepiece 1 includes a housing 2, a dial 52, hands 51, a bezel 11, and an operation receiving member that receives external operations such as push button switches P1 to P3 and a crystal oscillator C1. On the dial 52, the hands 51 are positioned to be rotatable, and the content corresponding to the direction indicated by the hands 51 is displayed. The display content by the hands 51 includes time display (which may be a date and time including a date and a day of the week). On the dial 52, a mark (hour mark 53) for indicating the displayed time is positioned. The dial 52 is made of a light-transmissive material.

[0011] On the dial 52, small windows 101 to 104 (dials) that occupy a part thereof are positioned. Some of the hands 51 rotate inside each of these small windows 101 to 104, and can display the day of the week, the alarm setting time, the time of other cities in the world (including UTC), the 24-hour display, and the like.

[0012] Also, the dial 52 has an opening 54 in the 6 o'clock direction. Below (on the back side) of the dial 52, a date disk 55 is positioned. By the rotation of the date disk 55, a mark (date mark) in the shape of a number corresponding to the date is selectively displayed from the opening 54. The date disk 55 is positioned between two concentric circles with different radii, and a numerical-shaped member is supported by support arms extending from the two concentric circles. Therefore, light is transmitted through the part other than the numerical-shaped member.

[0013] The housing 2 has a cylindrical shape with open upper and lower surfaces, and inside, in addition to the above-mentioned pointer 51, date wheel 55, dial plate 52, and hour markers 53, it contains a circuit board including a CPU (control unit, microcomputer) that controls operations such as timekeeping operations and display operations by the pointer 51, a drive unit 44 (stepping motor and gear train, see Fig. 4) that rotates the pointer 51 and date wheel 55 to change the positions they indicate, and a battery B (see Fig. 4), etc. The push button switches P1 to P3 and the capacitor C1 protrude outward from the side surface of the housing 2. The electrical signals related to these operations are transmitted through the housing 2 to the internal circuit board. At the 12 o'clock direction and 6 o'clock direction of the housing 2, the belt attachment portions 2a extend outward of the housing 2 in plan view. The housing 2 may be an insulating member such as resin or ceramic, or a metal member such as titanium. The lower end (rear side) of the housing 2 is sealed by a back cover (not shown).

[0014] Above the dial plate 52 and the pointer 51 (the upper end of the housing 2, the front side), it is covered by a transparent windproof member 8 (see Fig. 2), and the housing 2 is sealed. The periphery of the dial plate 52 is surrounded by a partition plate 6. Some or all of the hour markers 53, etc. may be fixed to the partition plate 6. Below the dial plate 52 and the date wheel 55, along the inner circumference of the partition plate 6, an annular solar panel 7 (outside the broken line in Fig. 1) is located. On the light-receiving surface of the solar panel 7, partially, members with low light transmittance or no light transmission at all (light non-transmitting members) such as the outer frames of the small windows 101 to 104, the hour markers 53, and the date markings of the date wheel 55 are located.

[0015] The bezel 11 is located at the peripheral part of the electronic clock 1. This bezel 11 may have markings indicated by the pointer 51. Also, the bezel 11 is used for decorative purposes. Further, when the electronic clock 1 performs radio wave reception, communication, etc., it may function as an antenna element.

[0016] Next, the solar panel 7 will be described. Figs. 2 and 3 are diagrams for explaining the solar panel 7. As shown in the front view of Fig. 2(a), the solar panel 7 has a plurality of arc-shaped solar cells 70a to 70c (collectively also referred to as solar cells 70). These plurality of solar cells 70 are arranged in a substantially circular shape and are connected in series with each other, so that the solar panel 7 outputs the sum of the electromotive forces of each solar cell 70. Here, the sum of the electromotive forces of the three solar cells 70, that is, a voltage approximately three times the electromotive force of each solar cell 70 can be output. The operating voltage of the electronic clock 1 is higher than the electromotive force of each solar cell 70. By connecting the three solar cells 70 in series, the solar panel 7 can output the charging voltage of the battery of the electronic clock 1 and the current corresponding to this voltage. Both ends of the solar cells 70 connected in series are located at one end of each of the solar cells 70b and 70c here and are connected to the connection electrode 751 in the 6 o'clock direction. Note that the solar panel 7 has an opening 79 at the same position as the opening 54 in plan view. Thereby, the floor 56 is exposed below the sun gear 55 in the position range corresponding to the openings 54 and 79.

[0017] Fig. 2(b) shows a schematic cross-sectional view taken along the section line AA of Fig. 2(a). In this schematic cross-sectional view, the sun gear 55 is omitted for simplicity of explanation. The solar panel 7 is located on the floor 56 located below the dial plate 52. The solar panel 7 is formed by stacking solar cells 70 on a substrate 80. Each solar cell 70 has a plate-like structure in which a power generation layer 72 is sandwiched between a pair of electrodes, namely a wiring electrode 71 (first electrode) and a lower electrode 73. The power generation layer 72 is a diode having a layer containing a compound semiconductor material such as InGaP. The wiring electrode 71 located on the side where light is incident from the outside among the electrodes is a narrow linear one (linear electrode) located along the outer edge of the solar cell 70. The wiring electrodes 71 of each of the solar cells 70a to 70c are located on the same circumference (concentric circles). The wiring electrode 71 is positioned and shaped so as to interfere with the incidence of light on the power generation layer 72 as little as possible. At one end of each of the three solar cells 70a to 70c, a connection conductor 757 is located that connects the wiring electrode 71 located on the upper surface side of the power generation layer 72 and the lower electrode 73 located on the lower surface side of the adjacent solar panel 7 to the solar panel 7 where this wiring electrode 71 is located.

[0018] The substrate 80 is an insulating member that supports the solar cell 70, and the insulating layer 81 and the support film 83 are adhered by the adhesive layer 82 therebetween. The insulating layer 81 is adhered to the solar cell 70. The combination of the insulating layer 81 and the support film 83 can be appropriately determined according to, for example, the combination of the adhesiveness and followability with the solar cell 70 and the support strength, etc.

[0019] The cut-off plate 6 is mirror-like above the power generation layer 72. The wiring electrode 71 may be located along the inner edge of the cut-off plate 6. Thereby, the light emitted from the wiring electrode 71 is likely to be reflected on the surface of the cut-off plate 6, and at the same time, the indirect light is easy to see from the display surface side, and it is easy to illuminate the pointer etc. located on the center side of the display surface.

[0020] One end of three solar cells 70 connected in series is the wiring electrode 71 of the solar cell 70b as shown in Fig. 2(a). Between the wiring electrode 71 and one of the connection electrodes 751, they are connected by a connection line 755 extending along the edge of the solar cell 70b (opening 79). The connection line 755 extends on the insulating surface (insulating layer 81) of the above-mentioned edge and is not included in the length of the wiring electrode 71 extending on the power generation layer 72 described later. The connection electrode 751 is connected by a lead-out electrode 753 inside the annular solar panel 7 and a lead-out wire 752. The lead-out wire 752 and the lead-out electrode 753 may be located on a covering member such as a laminate film that protects the upper surface of the solar cell 70. By laminating the formation surface of the lead-out wire 752 and the lead-out electrode 753 with the solar cell 70, the connection electrode 751 and the lead-out wire 752 are connected.

[0021] Fig. 3(a) is a schematic cross-sectional view of the solar panel 7 taken along the section line BB of Fig. 2(a). The lower electrode 73 forming the other end on the side opposite to the above-mentioned one end across the opening 79 is connected to the connection electrode 751. At the position overlapping the connection electrode 751 in plan view, the power generation layer 72 is removed, and a connection conductor 756 is located at this part instead. The connection conductor 756 electrically connects the lower electrode 73 and the connection electrode 751.

[0022] Between solar cells 70a and 70b and between solar cells 70a and 70c, as shown in Fig. 2(a), they are connected by connection conductors 757 respectively. Fig. 3(b) shows a schematic cross-sectional view taken along the cross-section line CC of Fig. 2(a). On this cross-section line CC, the lower electrode 73 of solar cell 70a and the wiring electrode 71 of solar cell 70c are connected by a connection conductor 757. At the part where the connection conductor 757 connects to the lower electrode 73, there is a gap part where the wiring electrode 71 and the power generation layer 72 are removed. The connection conductor 757 extends over the boundary wall 758 between solar cells 70a and 70c and onto the wiring electrode 71 of solar cell 70c.

[0023] As described above, when located on a part of the solar cell 70, light-non-transmissive members such as the hour numeral 53 and the frames of the small windows 101 to 104 cover the solar cell 70, and the power generation efficiencies of the respective solar cells 70a to 70c are different according to the area covered. The light-non-transmissive members are preferably located at the boundaries of the solar cells 70a to 70c as much as possible to suppress the decrease in power generation efficiency. For example, the hour numeral at 6 o'clock adjacent to the opening 54 in Fig. 1 overlaps with a part of the boundary between the solar cells 70b and 70c. Also, the frame of the small window 101 overlaps with a part of the boundary between the solar cells 70a and 70b. Fig. 3(c) shows an enlarged view of the vicinity of the boundary between the solar cells 70a and 70b with the date wheel 55 superimposed. In the state where the date is displayed statically, this date label 551 and the arm part 552 fixed to the annular frame body 553 that rotates the date label 551 overlap with the gap part between the solar cell 70a and the solar cell 70b.

[0024] However, depending on the shape and size of the members, etc., it is difficult to completely avoid positions where these members obstruct the incidence of light on the solar cell 70. In such a state, the three solar cells 70a to 70c are adjusted in size so that they can each generate the same amount of power when light is uniformly incident on the portions where light can be incident. The solar cell 70 of the present embodiment has different surface areas of the light-receiving surface, that is, angular widths with respect to the center of the solar cells 70 arranged in a ring shape. As shown in FIG. 1, the small windows 101 to 104 are respectively located in the 2 o'clock, 9 o'clock, 8 o'clock, and 4:30 directions on the dial plate 52. Therefore, compared with the solar cell 70a (the first solar cell) in the 12 o'clock direction, the solar cells 70b and 70c (the second solar cells) in the 4 o'clock and 8 o'clock directions are covered by the frames of the small windows 101 to 104 to a larger extent. Accordingly, as shown in FIG. 2(a), the solar cell 70a (at least a part) in the 12 o'clock direction has a smaller angular width than the other solar cells 70b and 70c in the 4 o'clock and 8 o'clock directions.

[0025] Note that regarding the portion corresponding to the opening 54 where the date mark of the date wheel 55 is displayed in the 6 o'clock direction of the display surface of the electronic clock 1, the solar cells 70b and 70c may not be located. For example, this portion may have a background color that makes the date mark easy to view. On the contrary, in portions other than the opening 54, since the solar panel 7 and the date mark have similar colors, it is difficult to view the date mark through the dial plate 52.

[0026] When a voltage (forward voltage) is applied to the diode structure of this solar panel 7, it emits light as an LED (Light Emitting Diode). When the compound semiconductor material is InGaP, red light (center wavelength of 664.5 nm) is emitted. In the electronic clock 1 of the present embodiment, by also using the solar cell 70 as an LED, the volume of providing a separate LED is omitted, and miniaturization and weight reduction are achieved.

[0027] The compounds are not limited to the above. For example, by using AlInGaP, the color becomes slightly closer to orange with a shorter wavelength. Since the wavelength is slightly shorter than the above red light, the color sensitivity of humans increases significantly. Therefore, the luminous efficiency is improved. In addition, a compound semiconductor material that emits light in an appropriate wavelength band may be used as long as sufficient power generation efficiency can be obtained.

[0028] At this time, the emission intensity is distributed depending on the current density at each location of the power generation layer 72. When the thin wiring electrode 71 is located on the power generation layer 72 as described above, the power generation layer 72 has an increasing emission amount (current density) along the wiring electrode 71. On the other hand, near the inner edge of the power generation layer 72, the emission amount is relatively small. That is, the emission of the power generation layer 72 becomes non-uniform.

[0029] The total current flowing through the three solar cells 70 arranged in series is constant. On the other hand, the density of the current crossing the power generation layer 72 vertically in each solar cell 70 depends on the length of the wiring electrode 71 because the cross-sectional area (width and thickness) perpendicular to the circumferential direction of the wiring electrode 71 is constant. As described above, since the angular widths of the respective solar cells 70 are different, if the wiring electrode 71 has a length corresponding to this angular width, the emission intensity becomes relatively large in the solar cell 70 with a narrow angular width.

[0030] In the electronic clock 1, while maintaining the difference in the surface areas of the respective solar cells 70, the lengths of the respective wiring electrodes 71 are made equal. That is, the contact areas of the respective wiring electrodes 71 with the power generation layer 72 are equal to each other. The equality here includes the error range assumed in normal design and manufacturing. For this reason, the solar cell 70a (first solar cell) has a protruding portion 76 that partially extends in the circumferential direction along the outer edge. The solar cells 70b and 70c (second solar cells) have notches 77 that are complementarily positioned with respect to the protruding portion 76 along the outer edge. In other words, at least one end of each solar cell 70 in the circumferential direction has a crank shape. Along with this, the wiring electrode 71 of the solar cell 70a extends up to the protruding portion 76 along the outer edge. On the other hand, the wiring electrodes 71 of the solar cells 70b and 70c that are on the same circumference as the wiring electrode 71 of the solar cell 70a are shorter by the amount of the notch 77 along the outer edge. That is, the length of the wiring electrode 71 of the solar cell 70a becomes longer than the angular width of the solar cell 70a by the amount of the protruding portion 76, and the length of the wiring electrodes 71 of the solar cells 70b and 70c becomes shorter than the angular width of the solar cells 70b and 70c by the amount of the notch 77. By appropriately determining the length of the protruding portion 76, the lengths of the wiring electrodes 71 become equal.

[0031] As described above, since the partition plate 6 is mirror-shaped, the light emitted from the solar panel 7 is reflected by the partition plate 6. By increasing the ratio of the reflected light compared to the directly emitted light, the solar panel 7 provides softer illumination as indirect illumination for illuminating the dial 52, the hands 51, and the like.

[0032] FIG. 4 is a block diagram for explaining the functional configuration of the electronic clock 1. The electronic clock 1 includes a CPU 41 (Central Processing Unit), a storage unit 42, an operation reception unit 43, a drive unit 44, and the like. As a configuration related to power supply, the electronic clock 1 includes, in addition to the solar cell 70 described above, a battery B, a switching unit S1, diodes D1, D2, and the like.

[0033] The CPU 41 is a processor that performs arithmetic processing and comprehensively controls the overall operation of the electronic clock 1. The CPU 41 may be a single processor, or a plurality of processors may operate in parallel or independently according to applications, etc.

[0034] The storage unit 42 includes a RAM which is a volatile memory, a flash memory which is a non-volatile memory, etc. The RAM provides a working memory space for the CPU 41 and stores temporary data. The non-volatile memory stores and holds programs related to operation control, various setting data, etc. The program includes a program related to the switching between the power generation operation and the light emission operation of the solar cell 70.

[0035] The operation reception unit 43 detects input operations such as the above push button switches P1 to P3 and the flow meter C1, etc., and outputs an operation signal corresponding to the detected content to the CPU 41. The drive unit 44 includes a stepping motor that applies a rotational torque to a gear train (gear train mechanism) for rotating the pointer 51, a drive circuit that outputs an operation voltage signal of the stepping motor based on the control of the CPU 41, etc. When the stepping motor rotates by a predetermined angle, each pointer 51 rotates by an angle corresponding to the rotation rate determined by the gear train mechanism.

[0036] The switching unit S1 is located between the solar cell 70 and the battery B. The switching unit S1 selectively switches between a path r1 (first circuit) via the diode D1 and a path r2 (second circuit) via the diode D2. The anode of the diode D1 is connected to the solar cell 70, and the cathode of the diode D2 is connected to the solar cell 70. When the path r1 via the diode D1 is selected and the solar cell 70 generates an electromotive force equal to or higher than the voltage of the battery B, the solar cell 70 outputs a current corresponding to the electromotive force via the diode D1 to charge the battery B. When the electromotive force of the solar cell 70 is insufficient, the voltage of the battery B is blocked by the diode D1 and the current does not flow to the solar cell 70.

[0037] When the path r2 through the diode D2 is selected by the switching unit S1 and the voltage of the battery B is higher than the electromotive force of the solar cell 70, a voltage is applied from the battery B to the solar cell 70 via the diode D2. As a result, the solar cell 70 emits light. When the electromotive force of the solar cell 70 is higher than the voltage of the battery B, the diode D2 blocks the connection between the solar cell 70 and the battery B.

[0038] Normally, the switching unit S1 selects the path r1 through the diode D1 (first mode). During this time, when the electromotive force of the solar cell 70 is higher than the voltage of the battery B, the solar cell 70 operates as a charging unit to charge the battery B. When a predetermined one of the push buttons P1 to P3 is pressed, the CPU 41 outputs a control signal corresponding to the pressing operation to the switching unit S1. The switching unit S1 selects the path r2 through the diode D2 for a set time in response to the control signal (second mode). If the voltage of the battery B is higher than the electromotive force of the solar cell 70 during this time, the solar cell 70 operates as an LED and emits light.

[0039] The switching unit S1 may have a switching element such as an MOSFET, for example. An N-channel MOSFET may be located in the path r2 so that the path r2 through the diode D2 is selected for the positive voltage control signal related to the lighting operation of the solar cell 70. Also, a P-channel MOSFET may be located in the path r1 through the diode D1.

[0040] [Second Embodiment] FIG. 5 is a front view of the electronic clock 1a according to the second embodiment. In this electronic clock 1a, instead of the solar panel 7 located along the inner edge of the index plate 6 in the electronic clock 1 of the first embodiment, a solar panel 7a is located inside the small window 102. Other configurations are the same, and the same components are denoted by the same reference numerals and the description thereof is omitted.

[0041] FIG. 6 is a diagram for explaining the solar panel 7a. The solar panel 7a has three fan-shaped solar cells 70d to 70f. Similar to the electronic clock 1, the sizes of the solar cells 70d to 70f may be different from each other according to the power generation efficiency. The solar cells 70d to 70f are located on a substrate 80a that encloses them in a plan view. The substrate 80a is, although not particularly limited, an insulating member having a regular hexagonal shape in a plan view and may have the same three-layer structure as the substrate 80 of the first embodiment.

[0042] Wiring electrodes 71d to 71f (collectively also referred to as wiring electrode 71a) are respectively located on the upper surfaces of the respective solar cells 70d to 70f. In the electronic clock 1a of this embodiment, the wiring electrode 71a is located along the contours of characters, patterns, line drawings, etc. That is, by strongly emitting light along the wiring electrode 71a, characters, figures, etc. having a contour corresponding to the wiring electrode 71a appear. Note that the wiring electrodes 71d to 71f are preferably kept within a length range that does not adversely affect power generation.

[0043] At this time, by making the lengths of the wiring electrodes 71d to 71f the same, the respective light emission intensities are made uniform and light emission unevenness does not occur. Note that the wiring electrodes 71d to 71f have both ends at the boundaries of the solar cells 70d to 70f, respectively. One end of each of the wiring electrodes 71d to 71f extends along the gap located at the boundary of the solar cells 70d to 70f and is drawn out to the outside of the solar cell 70. The lead electrodes 751a located at both ends of the three series-connected solar cells 70d to 70f are connected to the supply of the battery and the light emission voltage. Thereby, in the electronic clock 1a, the solar panel 7a operates as an LED according to a control signal.

[0044] Such lighting operations of characters and patterns may be executed together with a notification sound and vibration, for example, when an alarm notification operation is executed. Alternatively, it may be executed in response to a pressing operation of a predetermined one of the push button switches P1 to P3.

[0045] By generating electricity and emitting light only within a specific small window 102, other parts of the dial 52 can be designed without considering the incidence of light on the solar panel 7a. Therefore, it becomes possible to easily widen the width of the design of the display surface.

[0046] As described above, the electronic clock 1 of the present embodiment includes a solar cell 70 having a wiring electrode 71 and a lower electrode 73 which are a pair of electrodes, and a power generation layer 72 sandwiched between these pair of electrodes and containing a compound semiconductor material capable of emitting light by applying a voltage to these pair of electrodes. In this way, not only can the electronic clock 1 operate as a power generation unit for charging the solar cell 70, but also by applying a voltage between the electrodes, it can operate as a light emitting unit. This saves the space for mounting both, and miniaturization and weight reduction of the electronic clock 1 are achieved. The operation as a power generation unit where the incident light amount is large and the operation as a light emitting unit where the incident light amount is scarce are almost exclusive. Therefore, the electronic clock 1 is less likely to cause functional problems or inconvenience to the user. Thus, the electronic clock 1 can efficiently achieve both power generation and light emission.

[0047] Also, the electronic clock 1 has a plurality of solar cells 70a to 70c. The plurality of solar cells 70a to 70c are connected in series, and each of the wiring electrodes 71 among the pair of electrodes (wiring electrode 71 and lower electrode 73) has an equal contact area with the power generation layer 72. The light emission in the power generation layer 72 is biased towards the current path from the wiring electrode 71 to the lower electrode 73, so the light emission intensity near the wiring electrode 71 becomes larger than the surroundings. Such uneven light emission is likely to be noticeable in such a portion with a large light emission intensity. If the contact areas are equal, the current density from the wiring electrode 71 to the power generation layer 72 becomes substantially uniform, so the electronic clock 1 can suppress the unevenness of the above-described light emission intensity.

[0048] Further, at least some of the plurality of solar cells 70 may have a different light-receiving surface area from other solar cells 70. It is preferable that the power generation electromotive forces of the plurality of solar cells 70 are about the same. When the arrangement range of the solar cells 70 is limited as in the electronic clock 1 and it is difficult to completely avoid the influence of other members, considering the influence, the surface areas of the solar cells 70 are made different, and the size can be relatively increased by the amount of the influence (shading). Thereby, the electronic clock 1 can efficiently adjust the electromotive force without arranging the solar cells 70 and other members so as to completely avoid other members.

[0049] Further, the plurality of solar cells 70 may each have an arc shape and be arranged in a substantially annular shape as a whole. The wiring electrodes 71 are linear electrodes extending along the outer edges of the arc shapes, respectively. Thereby, the wiring electrodes 71 can hardly prevent the incident light related to the power generation of the solar cells 70.

[0050] Also, like the electronic clock 1a of the second embodiment, the wiring electrode 71a is a linear electrode, and the linear electrode may have the same length for each of the plurality of solar cells 70d to 70f. Contrary to the electronic clock 1 of the first embodiment, specific display may be performed using strong light emission along the wiring electrode 71a. Even in this case, the electronic clock 1a can suppress unevenness in light quantity by making the lengths of the wiring electrodes 71a uniform.

[0051] Further, the solar cell 70a has a protruding portion 76 that partially protrudes from an end portion along the outer edge of a substantially annular shape, and the solar cells 70b and 70c have notches 77 that are complementarily positioned with respect to the protruding portion 76. The wiring electrode 71 is a linear electrode. The wiring electrode 71 of the solar cell 70a and the wiring electrodes 71 of the solar cells 70b and 70c are located on the same arc passing through the protruding portion 76 and the notch 77, and have the same length for each of the plurality of solar cells 70a to 70c. In this way, by partially varying the length along the arc by the protruding portion 76 and the notch 77 along the circumferential direction, the length of the linear wiring electrode 71 can be appropriately adjusted without greatly changing the ratio of the areas of the solar cells 70.

[0052] Further, the electronic timepiece 1 includes a switching unit S1 that switches between a first mode of outputting the electromotive force of the solar cell 70 and a second mode of applying a voltage to the solar cell 70. Therefore, the electronic timepiece 1 can emit light appropriately according to the desired situation of the user or the like, and when the solar cell 70 does not emit light, it can output an electromotive force corresponding to the input light.

[0053] Also, the electronic timepiece 1 includes a path r1 for outputting the electromotive force of the solar cell 70 in the first mode as described above, and a path r2 for supplying the voltage applied to the solar cell 70 in the second mode. Such an individual input / output circuit can suppress a reverse current according to the magnitude of the electromotive force of the solar cell 70 and the voltage of the battery B, and can switch between power generation and light emission by the solar cell 70 with simple wiring.

[0054] Also, the wiring electrode 71a may form a pattern or characters in a plan view. As described above, since the lengths of the wiring electrodes 71a are uniform, unevenness of characters and patterns can be suppressed, and the electronic timepiece 1 can appropriately display patterns and characters.

[0055] Also, at least a part of the boundaries between the plurality of solar cells 70 may be covered by the time character 53, which is a light-non-transmissive member, the frames of the small windows 101 to 104, the date wheel 55 (when stationary), or the like. Since the boundary portion does not emit light at all when the solar cell 70 emits light, by overlapping this with a light-non-transmissive member where light is not directly emitted, the electronic timepieces 1 and 1a can make the gaps in the light emission less conspicuous.

[0056] Note that the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, in the above embodiment, even when the path r2 is selected, if the generated electromotive force of the solar cell 70 is greater than the voltage of the battery B, it may not be necessary to switch from the path r1 to the path r2. Further, the switching unit S1 may have a well-known circuit configuration capable of switching between the paths r1 and r2. Alternatively, even if there are no separate paths r1 and r2, if the switching unit S1 can appropriately switch between power generation and light emission, a common single path may be connected to the solar cell 70.

[0057] Also, in the above embodiment, there were three solar cells 70 each, but it is not limited to this. There may be two or four or more depending on the required total voltage.

[0058] Also, in the above embodiment, it was described that the light emission amounts of the respective solar cells 70 are made uniform, but it is not limited to this. For example, the ratio of the lengths of the wiring electrodes 71 and 71a may be determined so that some of a plurality of characters, symbols, etc. have a weaker or stronger light emission amount than others.

[0059] Also, in the above embodiment, the wiring electrodes 71 and 71a were described as being linear, but the thicknesses of the wiring electrodes 71 and 71a do not have to be uniform. Considering design and the like, the wiring electrodes 71 and 71a may be partially thick or thin.

[0060] Also, the wiring electrode 71 may be a plurality of parallel extending ones. Figure 7 is a modified example of the solar panel 7 of the first embodiment. The wiring electrode 71b may be two parallel extending ones. By having a plurality of such wiring electrodes 71b, even if any one of the wiring electrodes 71b is cut, the electronic clock 1 can continue the power generation operation of the solar cell 70.

[0061] Also, even in the electronic clock 1a of the second embodiment, the wiring electrode 71a is positioned along the inner edge of the frame of the small window 104, and it is not necessary to display characters, figures, etc. Also in this case, the shape of the frame of the small window 104 or the like may be determined so that the emitted light from the solar cell 70 becomes indirect light as much as possible.

[0062] Also, in the above embodiment, the electronic clocks 1 and 1a have been described as performing display by the hands 51, but the present invention is not limited to this. An electronic clock that performs digital display may also be used.

[0063] Also, the structure of the electronic clocks 1 and 1a, for example, the presence or absence of the dial plate 52 and the date wheel 55 and the positional relationship with the solar cell 70 can be appropriately determined according to the design within the range where the solar cell 70 can generate electricity and emit light. In addition, the specific configurations, the contents and procedures of the processing operations shown in the above embodiments can be appropriately changed without departing from the spirit of the present invention. The scope of the present invention includes the scope of the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0064] 1, 1a Electronic clock 2 Housing 2a Mounting portion 6 Partition plate 7, 7a Solar panel 8 Windshield member 11 Bezel 41 CPU 42 Storage unit 43 Operation reception unit 44 Driving unit 51 Hands 52 Dial plate 53 Hour numerals 54 Aperture 55 Date wheel 551 Date marker 552 Wrist portion 553 Frame body 56 Floor 70, 70a~70f Solar cell 71, 71a, 71b, 71d~71f Wiring electrode 72 Power generation layer 73 Lower electrode 751 Connection electrode 751a Lead-out electrode 752 Lead-out wire 753 Lead-out electrode 755 Connection wire 756, 757 Connection conductor 758 Boundary wall 76 Protrusion 77 Notch 79 Opening 80, 80a Substrate 81 Insulating layer 82 Adhesive layer 83 Support film 101 - 104 Small window B Battery D1, D2 Diode P1 - P3 Push-button switch S1 Switching part r1, r2 Path

Claims

1. A pair of electrodes, A power generation layer sandwiched between the pair of electrodes and containing a compound semiconductor material capable of emitting light when a voltage is applied to the pair of electrodes, A solar cell having an arc shape, An electronic clock in which a first electrode on the side where light is incident among the pair of electrodes is a linear electrode extending along the outer edge of the arc shape.

2. A pair of electrodes, A power generation layer sandwiched between the pair of electrodes and containing a compound semiconductor material capable of emitting light when a voltage is applied to the pair of electrodes, A plurality of solar cells having, The plurality of solar cells are connected in series, An electronic clock in which each of the first electrodes, which are linear electrodes on the side where light is incident among the pair of electrodes, has an equal contact area with the power generation layer and is of equal length for each of the plurality of solar cells.

3. A pair of electrodes, A power generation layer sandwiched between the pair of electrodes and containing a compound semiconductor material capable of emitting light when a voltage is applied to the pair of electrodes, A solar cell having, An electronic clock in which a first electrode, which is a linear electrode on the side where light is incident among the pair of electrodes, forms a pattern or characters in plan view.

4. A plurality of the solar cells are provided, The plurality of solar cells are connected in series, Each of the first electrodes has an equal contact area with the power generation layer The electronic clock according to Claim 1.

5. The electronic clock according to Claim 4, wherein at least some of the plurality of solar cells have a different surface area of the light-receiving surface from that of the other solar cells.

6. The plurality of solar cells each have an arc shape and are arranged in a substantially circular shape as a whole, The first electrode is each of the linear electrodes extending along the outer edge of the arc shape, The electronic clock according to Claim 4.

7. The plurality of solar cells include a first solar cell and a second solar cell arranged side by side, The first solar cell has a protruding portion that partially protrudes from an end along the outer edge, The second solar cell has a notch portion that is complementary to the protruding portion, The first electrode of the first solar cell and the first electrode of the second solar cell are located on the same arc passing through the protruding portion and the notch portion and are of equal length for each of the plurality of solar cells, The electronic clock according to Claim 6.

8. An electronic clock according to Claim 1, comprising a switching unit for switching between a first mode of outputting the electromotive force of the solar cell and a second mode of applying a voltage to the solar cell.

9. A first circuit for outputting the electromotive force in the first mode, A second circuit that supplies the voltage applied in the second mode; The electronic timepiece according to claim 8, comprising:

10. The electronic timepiece according to claim 4, wherein at least a part of the boundaries between the plurality of solar cells is covered with a light-non-transmissive member.

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