Watch with display lighting device

Abstract

This invention relates to a watch with a display illumination device, comprising: a display; a watch crystal (6) disposed above the display and having an effective area (9) through which the watch user can see the display; and an illumination device comprising at least one electroluminescent unit (14a) disposed below the watch crystal and formed by at least one light source (particularly an LED or OLED). The at least one electroluminescent unit is powered from a peripheral contact area (30a to 30d) stacked on the edge of the watch crystal via a conductor pad (22g to 22j) made of a transparent conductive material, the conductor pad covering all of the effective area except for gaps (26a to 26d) separating the conductor plates, at least within the effective area. A significant feature is that each gap separates two adjacent conductor areas, and its width (particularly less than 100 μm, preferably less than 50 μm) is such that the gap is imperceptible to the watch user at a distance of approximately 30 cm under normal ambient light.

Description

Technical Field

[0001] This invention relates to the field of watches with analog or digital displays (typically displaying at least the current time) and lighting devices for such displays. More specifically, this invention relates to an active lighting device, in other words, a device comprising at least one light source powered by electrical energy (particularly via a controller). Background Technology

[0002] Various active lighting devices (“active” is the opposite of passive lighting devices, particularly the arrangement of phosphorescent material on the dial and / or pointers) have been proposed for reading analog displays in dark or black environments (i.e., spaces not illuminated by external light sources).

[0003] Specifically, document WO 02 / 23637 describes a watch with an analog display and an electroluminescent diode (also known as an "LED," an abbreviation of "Light Emitting Diode") positioned at the center of the lower surface of the watch crystal. The LED draws power from the periphery of the crystal via two straight lines made of a transparent conductive material, indium tin oxide (a mixture of indium oxide and tin oxide, also known as ITO). The advantage of this lighting device is that the electroluminescent diode can be small enough to be inconspicuous, even almost imperceptible to the user, especially when aligned with the axis of the hands on the analog display. However, the lighting device described in the aforementioned document has two drawbacks. First, the distance between the periphery of the crystal and the center is relatively long. Therefore, the two straight conductive lines are narrow and have high resistance, which limits the current supplied to the LED, thus limiting its luminous output at a given voltage. Second, although the ITO lines are highly transparent, they are still visible when the crystal is slightly darkened. The user can still discern them under certain lighting conditions, which is not only unsightly but may even indicate a manufacturing problem with the crystal. Summary of the Invention

[0004] The object of the present invention is to solve the two problems encountered in the prior art as described above in the background section.

[0005] Therefore, the present invention relates to a watch comprising a display, a crystal, and a lighting device. The crystal is arranged above the display and has an effective area through which the watch user can see the display. The lighting device includes at least one electroluminescent unit arranged below the crystal and above the display. The electroluminescent unit is composed of at least one light source (especially an LED or OLED (an abbreviation for "organic light-emitting diode"). The at least one electroluminescent unit obtains power from a peripheral contact area arranged axially stacked outside the effective area via a conductive pad made of a transparent conductive material. The conductive pad covers... The effective area of ​​the watch crystal includes at least the entire lower portion, except for a gap separating two conductor pads in the case of a single electroluminescent unit with only two power contacts; and except for multiple gaps separating the conductor pads in the case of a single or multiple electroluminescent unit with at least three power contacts. A significant feature is that each gap separates two adjacent conductor pads and has a width such that, under normal ambient light, the gap is almost imperceptible or preferably imperceptible to a watch user with normal vision, and the width of the gap or multiple gaps is less than two hundred micrometers (200 μm).

[0006] In a preferred embodiment involving one or more electroluminescent units having at least three power contacts, each conductor pad, each electrically connected to a single power contact associated with a single light source, is configured such that it has substantially the same resistance between its respective peripheral contact area and the corresponding power contact on the electroluminescent unit or electroluminescent unit.

[0007] In a particular variant, the conductor pad shared by multiple power contacts is configured to have lower resistance compared to individual conductor pads. Attached Figure Description

[0008] The invention will now be described in more detail with reference to the accompanying drawings, which are given by way of non-limiting example, wherein:

[0009] - Figure 1 This is a schematic cross-sectional view of a watch according to a first embodiment of the present invention;

[0010] - Figure 2 This is a top view of a first variation of the first embodiment, showing the portion of the lighting device arranged below the watch face;

[0011] - Figure 3A This is a top view of a second variation of the first embodiment, showing the portion of the lighting device arranged below the watch face;

[0012] - Figure 3BThis is a top view of a third variation of the first embodiment, showing the portion below the watch face where the lighting device is arranged;

[0013] - Figure 4 This is a schematic cross-sectional view of a watch according to a second embodiment of the present invention;

[0014] - Figure 5 This is a top view of a first variation of the second embodiment, showing the portion below the watch face where the lighting device is arranged; and

[0015] - Figure 6 This is a top view of a second variation of the second embodiment, showing the portion of the lighting device arranged below the watch face. Detailed Implementation

[0016] The following will refer to Figures 1 to 3B A first embodiment of the watch according to the present invention is described.

[0017] Overall, the watch 2 includes a case 4, a movement 10, an analog display 12, a crystal 6 positioned above the analog display, and a lighting device. The lighting device includes at least one electroluminescent unit, such as an LED or OLED, positioned below the crystal and above the analog display. The crystal 6 has an effective area 9 that overlaps within an upper opening 9a of the case 4, through which the watch user can see the analog display 12. Specifically, the case 4 consists of a central component 4a, a bezel 4b, and a case back 4c. The analog display 12 includes a set of hands and a dial 11.

[0018] exist Figure 2 In the first variant shown, the electroluminescent unit is an LED 14, which is arranged on a structured conductive material layer 16 deposited on the lower surface 8 of the crystal 6 and almost completely covers the entire effective area 9 of the crystal for the watch user within the watch case. In the variant shown, the conductive layer 16 almost completely covers the lower surface 8 of the crystal. The conductive layer 16 is configured to form conductive pads for powering the LED 14, or, in other variants described below, for powering the LED or OLED. More specifically, the LED 14 receives power from two peripheral contact areas 20a and 20b arranged axially stacked on the outside of the effective area 9 (i.e., along the perimeter 7 of the crystal) via two power contacts 24 arranged on the LED on the same side as the conductive layer 16, via two conductive pads 22a and 22b made of transparent conductive material, which at least cover the entire lower portion of the effective area 9 of the crystal 6, except at the gap 26 separating the only two conductive pads 22a and 22b. These two conductor pads (also referred to as "electrodes") each cover almost half of the effective area 9.

[0019] Currently, there are extremely small electroluminescent light sources on the market, i.e., microlight sources, which are almost invisible to the naked eye. These microlight sources are very small (<500μm). The two main types are well-known: LEDs and OLEDs, the latter of which can be very small and fabricated directly on a transparent substrate. LEDs are typically less than 1 mm in size, and advantageously, their side lengths are all less than 500μm, making them difficult to see when turned off. In one particular variant, a size of 150 × 100μm was chosen. 2 The LEDs are small, meaning their side length is less than 200μm, making them virtually imperceptible to users with normal vision at a distance of about 30cm. The preferred size is approximately equal to or less than 100×100μm. 2 These are tiny LEDs, so small that they are virtually imperceptible to watch users with normal vision at a distance of about 30cm—in other words, invisible to the naked eye. These tiny LEDs can be blue, green, yellow, or red, or even white. To create a white LED, phosphorescent material is deposited on a blue LED to convert the blue light into yellow light. The remaining blue light emitted by the LED mixes with the yellow light produced by the phosphorescent material, resulting in white light perceived by the naked eye.

[0020] Advantageously, the transparent conductor pads 22a and 22b are formed by photolithography or by printing silver nanostructures onto a thin transparent conductor layer 16 made of a transparent conductor oxide. As a common example, the transparent conductor oxide is indium tin oxide (ITO) or indium zinc oxide (IZO, an abbreviation of "Indium Zinc Oxide"). Other techniques for forming transparent conductor pads and other transparent conductor materials will be apparent to those skilled in the art.

[0021] The electrical connection between the power contacts 24 on LED 14 and the transparent conductive pads 22a and 22b can be achieved in several ways. For example, isotropic or anisotropic conductive adhesives or eutectic solders can be used. For isotropic conductive adhesives, especially those based on silver particles, two separate, very small adhesive beads ensure adhesion between the LED and the substrate and ensure conductivity between the surface / contact pads or contact pillars (referred to as power contacts) on the LED and the transparent conductive pads 22a and 22b. For anisotropic conductive adhesives, especially those made with gold microspheres, a single extended adhesive surface beneath LED 14 ensures adhesion between the LED and the substrate and ensures conductivity between the power contacts 24 on the LED and the transparent conductive pads 22a and 22b only along an axis orthogonal to the lower surface 8 of the mirror 6. It should be noted that in the accompanying drawings, the power contacts 24 are schematically drawn as continuous lines so that they are clearly visible and easily identifiable, and since they are located beneath the LED substrate, they are therefore hidden by the substrate when viewed from the bottom in the top views shown in the figures.

[0022] In the case of eutectic bonding (i.e., bonding low-melting-point alloys), the power contacts 24 on the LED are pre-covered with an alloy layer, particularly a gold / tin (Au / Sn) alloy, and the relevant areas on the conductor layer (substrate) are covered with a metal layer, particularly a gold (Au) metal layer. During bonding, the LED contacts rub against the substrate and generate heat, causing the contact surfaces to melt. After cooling, the LED is firmly bonded to the substrate, forming a good low-resistance contact. Compared to conductive adhesive, this process achieves lower contact resistance and higher adhesive strength, but requires more thorough surface pretreatment of the LED contacts and the substrate.

[0023] exist Figure 2 In this design, two peripheral contact areas 20a and 20b extend radially from two conductor pads 22a and 22b. They are made of the same transparent conductive material as the conductor pads through a structuring / construction process of conductor layer 16 and are also separated from each other by gap 26. In fact, these two peripheral contact areas are indistinguishable from the two conductor pads except that the peripheral contact areas are arranged axially stacked outside the effective area 9 of the watch crystal 6, outside the opening 9a of the watch crystal plane, and extend along the perimeter 7 of the watch crystal, making the electrical connector 36 between the power circuit 34 and the peripheral contact areas 20a and 20b invisible to the user of the watch 2.

[0024] It should be noted that although the ITO or IZO conductor pads are transparent, they are slightly tinted and alter the light reflection on the lower surface 8 of the watch crystal 6 (especially the sapphire crystal) relative to the portion without the conductor layer, thus allowing the naked eye to distinguish the areas of the watch crystal 6 with and without the conductor layer. Furthermore, the height at the edge of each conductor pad varies slightly, allowing the watch user to see the fine lines. According to the invention, generally, the width of the gap 26 makes it advantageously almost imperceptible to a watch user with normal vision under normal ambient light, or preferably imperceptible at approximately 30 cm. One advantage of having a larger contact area is that the conductor pads are thinner than in the case of conductor lines (which are inherently narrow), while maintaining good conductivity, even better than such conductor lines. The thinner the conductor layer of the conductor pad, the better the transparency, and the lower the visibility of the upper edge of the conductor pad.

[0025] "Gap" refers to a tiny space or slit between two material regions that separates them. To minimize the contrast between the conductor pad and the substrate (i.e., the mirror 6), the gap 26 (in other words, space / slit) between the two conductor pads is preferably as narrow as possible, while ensuring electrical insulation between these conductor pads. For example, a very narrow gap of about 10 μm can be formed between two conductor pads by using photolithography to construct an ITO layer.

[0026] Generally, the width of the gap is less than 200 micrometers (200 μm). In an advantageous variation, the width is less than 100 micrometers (100 μm). In a preferred variation, the width is less than 50 micrometers (50 μm).

[0027] Transparent conductive pads 22a and 22b are connected to the power supply circuit 34 via at least one connector. Figure 1 In the illustrated variant, a cylindrical, spring-loaded connector 36 is shown, capable of connecting a single transparent conductor pad to the power circuit. In the first variant, two connectors 36 are provided, one for each of the two transparent conductor pads. In another variant, the electrical connection is achieved by an anisotropic elastomer conductor (Zebra®) disposed in one of the two peripheral regions (through which gap 26 extends). To ensure that the electrical connection between the power circuit 34 and the peripheral contact regions 20a and 20b is not visible to the watch user, the connector 36 is disposed behind the flange 38 that constitutes / defines the display space of the watch 2.

[0028] Figure 3A and 3B The second and third variations are shown. In both variations, the electroluminescent unit 14a consists of three LEDs arranged on the same support and sharing a common anode or cathode, while each LED has an independent cathode or anode, resulting in the electroluminescent unit 14a having four power contacts 24. This electroluminescent unit 14a is designed to provide white light via three LEDs (micro-LEDs) that emit red, green, and blue light respectively. In another variation, two LEDs can be used, one emitting blue light and the other yellow light. By supplying power to the three LEDs separately, the lighting color can be adjusted as needed to obtain a specific white light.

[0029] exist Figure 3AIn this design, unit 14a receives power from four peripheral contact areas 20c to 20f located along the edge of the watch crystal 6 via four conductive pads 22c to 22f made of transparent conductive material. These conductive pads cover the entire effective area 9 of the watch crystal, except for four gaps 26b to 26d used to separate pairs of conductive pads. This means that each gap separates two adjacent conductive pads. Similarly, the width of each gap is such that it is almost imperceptible, preferably almost imperceptible to the watch user at a distance of approximately 30cm under normal ambient light. The various preferred width ranges described above also apply to all other variations. In this second variation, each transparent conductive pad extends substantially over one-quarter of the lower surface of the watch crystal. This variation is advantageous if only one LED is activated at a time. Therefore, there are four identical conductive pads 22c to 22f. The peripheral contact areas 20c to 20f used to extend the conductive pads are spaced apart along the periphery of the watch crystal. This introduces certain drawbacks to the electrical connection device of the power supply circuit, as it must be set at an angular distance greater than 180° along the edge of the watch crystal, thus also introducing certain drawbacks to the electrical connectors that are electrically connected to the power supply circuit. Specifically, four cylindrical connectors 36 equipped with springs can be set, spaced apart or arranged in pairs on both sides of the gap along the edge of the watch crystal, or two anisotropic elastomer conductors with opposite diameters can be set, each conductor covering one gap, i.e., gaps 26a and 26c or gaps 26b and 26d.

[0030] Figure 3B The third variant shown overcomes the aforementioned shortcomings of the second variant. The peripheral contact areas 30a to 30d on conductor pads 22g to 22j are arranged side-by-side in the same local connection segment 29, which in this example extends over less than one-eighth of the periphery 7 of the lens, where the peripheral contact areas are arranged in a row. In a general variant, the connection segment extends over less than one-eighth of the periphery 7 of the lens. To achieve uniform luminescence and maximum total power among the LEDs, the structural pattern of conductor pad 16 is designed such that each electrode / conductor pad (each electrode / conductor pad is electrically connected to a single power contact 24 dedicated to a single LED) has substantially the same resistance between the power contact and the corresponding peripheral contact area. Figure 3B In this configuration, the individual conductor pads are labeled 22h to 22j. The common conductor pad 22g (which connects to the power contact 24 on the electroluminescent unit 14a shared by the three LEDs) is configured such that its resistance is lower than that of the individual conductor pads associated with a single LED. In the second variant, as... Figure 3AAs shown, all conductor pads are similar and have the same resistance. It should be noted that in the second variation, the common conductor pad can also have a lower resistance, for example, by constructing conductor layer 16 such that the common conductor pad extends over a larger angular distance (specifically 150°), while the three individual conductor pads extend over the same smaller angular distance (i.e., 70°).

[0031] Although the light source is positioned to emit light towards the dial 11, it also emits some light outwards, which can affect aesthetics and dazzle the watch wearer. In fact, this light emitted directly upwards is often more intense than light reflected from the dial and can interfere with the readability of the display. One solution is to add an opaque, optionally reflective, overlay between the outer crystal and the electroluminescent unit (especially the LED).

[0032] To block light emitted by the electroluminescent unit from the user using a capping layer, various configurations can be considered. Advantageously, the capping layer can be formed on one side of the lower surface 8 of the mirror, directly on that surface, or between the transparent conductor layer 16 and the electroluminescent unit / LED. In the latter case, the capping layer must simultaneously ensure the required optical opacity and the conductivity required to power the electroluminescent unit / LED. The following two implementations are feasible:

[0033] - The cover layer is made of structured black resin, which includes openings filled with conductive material to enable electrical contact between the transparent electrodes and the power contacts on the electroluminescent unit.

[0034] - The cover layer is made of an opaque anisotropic conductive adhesive used to attach and electrically connect the electroluminescent unit. The adhesive contains, for example, conductive metal beads incorporated into a resin, and is optically opaque by adding non-conductive absorbing pigments.

[0035] The following will refer to Figures 4 to 6 The second embodiment is described. Elements and reference numerals similar to those in the first embodiment will not be repeated here. Figure 5 and Figure 6 Top views of a first and second variant of a portion of a lighting device according to a second embodiment of the present invention are shown, the portion of which is arranged below the watch crystal.

[0036] The second embodiment differs from the first embodiment primarily in two specific features. First, a plurality of spaced-apart electroluminescent units 14b are arranged below the watch crystal 6 within an effective area 9 formed by the opening 9a of the bezel 4b on the watch case 4. Second, the electroluminescent units 14b are arranged on a transparent substrate 44, which is separate from the watch crystal and bonded below the watch crystal with a layer of transparent adhesive 50. Advantageously, the electroluminescent units / light sources 14b are manufactured using OLED technology, and each electroluminescent unit / light source 14b has a light-emitting surface at the μm level, which is imperceptible to the naked eye within a range of approximately 30 cm. Preferably, from a top view, the surface area of ​​each OLED 14b is substantially equal to or less than 100 × 100 μm. 2 The transparent substrate 44 can be made of glass, sapphire, PC, PMMA, or other transparent polymers. It should be noted that in another variation, the light source is positioned below the transparent substrate 44 on the side of the analog display 12.

[0037] LEDs are typically fabricated in a preparatory step and then placed and attached to the watch face 6 or another transparent substrate 44 (considering a variation), while OLEDs are fabricated directly on the lower surface 8 (considering a variation) of the watch face 6 or another transparent substrate 44, which covers the entire effective area 9 of the watch face 6. Figure 4 As shown. For OLEDs, the light-emitting surface is obtained by constructing the functional layers (anode, organic layer, cathode) for each OLED. First, transparent conductor pads 22g (common conductor pad) and (independent conductor pads) 22h to 22k in the first variant, or (common conductor pad) 22p and (independent conductor pad) 22n in the second variant, are deposited on a transparent substrate 44. Second, the anode on OLED 14b is formed on the corresponding contact areas of the independent conductor pads 22h to 22k. Third, an organic layer is deposited on the anode; fourth, a cathode is deposited on the organic layer, wherein a portion of each cathode extends beyond the corresponding organic layer and covers the contact areas on the common conductor pad 22g. Finally, the OLED is covered with a protective layer, for example, made of glass, using conventional methods.

[0038] According to the invention, similar to the first embodiment, the electroluminescent unit 14b receives power from peripheral contact areas 30a to 30e in the first variant or from 30a and 30n via conductor pads 22g to 22k or 22p and 22n respectively in the second variant. These conductor pads are made of a transparent conductive material on a transparent substrate 44. The peripheral contact areas 30a to 30e or 30a and 30n are arranged side-by-side, preferably in a row, in the same connecting segment 29 located on the edge of the transparent substrate 44, outside the effective area of ​​the watch face 6 in axial projection, and within a limited angular sector. The conductor pads at least cover the entire lower portion of the effective area 9 of the watch face 6, except for the gaps 28 used to separate these conductor pads. Each gap separates two adjacent conductor pads, and its width is such that the gap 28 is not perceptible to the watch user when viewing the display under normal ambient light. The advantageous and preferred numerical ranges for the gap widths described above also apply to the second embodiment.

[0039] Preferably, in order to achieve uniform luminescence and maximum total illumination power among the light sources (i.e., OLED 14b), the transparent conductive pads in the conductive layer 16 covering the transparent substrate 44 are configured to achieve low resistance between the peripheral contact area and the corresponding power contacts on the OLED 14b, which is substantially equal for each conductive pad. This is because the transparent conductive pads extend over at least the entire surface area formed by the effective region 9 of the watch mirror 6 (excluding the gap 28). Furthermore, as mentioned above, since the gap is very narrow and almost imperceptible, preferably completely imperceptible to the naked eye, this advantageous characteristic allows the presence of the conductive electrodes extending towards the lower surface 8 of the watch mirror to be hidden, at least within the axial projection of the effective region 9. This makes the illumination device according to the invention very inconspicuous. It should be noted that the expression "effective region of the watch mirror" should be understood as the cylindrical space with an axial direction and an outer periphery formed by the opening 9a of the bezel 4b on the watch case 4.

[0040] A common conductor pad 22g or 22p connected to multiple corresponding power contacts on the OLED is configured to have a lower resistance between these power contacts and the peripheral contact area 30a compared to the individual conductor pads 22h to 22k or 22n, because the common conductor pad has a higher current flowing through it (as it collects multiple currents from the individual conductor pads).

[0041] The cathode is preferably made of an opaque material to prevent the OLED from emitting light axially through the mirror 6. Advantageously, the cathode is reflective. Importantly, each cathode covers a very small area on the common conductor pad outside the organic layer to prevent it from being seen. To keep the size of the cathode to a minimum, the contact area on the common conductor pad 22g should be as close as possible to the light-emitting area on the OLED, located at the periphery of the light-emitting organic layer. As in the first embodiment, an opaque and optional reflective capping layer may also be provided above each OLED, for example deposited on the lower surface 8 of the mirror, facing the OLED. When assembling the mirror 6 to the transparent substrate 44 using adhesive 50, care must be taken to align the capping layer with the OLED point by point, or, in another example where LEDs are used instead of OLEDs, align the capping layer with the LEDs point by point.

[0042] Preferably, the electrical connection between the peripheral contact areas arranged in a straight line and the power supply circuit 34 is achieved using a flexible circuit board 48.

[0043] The first variant ( Figure 5 In the second variant, the lighting device includes four light sources 14b (each an electroluminescent unit formed by a single OLED or LED), arranged at regular intervals along the angular direction, with the angular distance between two adjacent light sources equal to 90°. A common conductor pad 22g occupies the central area on the transparent substrate 44 and the connector area from this central area to the peripheral contact area 30a, while individual conductor pads extend around the central area. Figure 6 In this embodiment, the lighting device includes twelve light sources 14b, each positioned above different digits indicating one to twelve hours on the dial. A common conductor pad 22p occupies the peripheral area and the inner area substantially along the diameter direction on the transparent substrate 44, while individual conductor pads 22n radiate outward from the contact area 30n. In this second variant with a relatively larger number of independent light sources 14b, the transparent substrate 44 includes an outer protrusion 45 on which a connecting segment 29 is located.

[0044] The lighting device according to the invention can also be used as a "front light" system for watches with purely reflective digital displays (also known as "electronic displays"), enabling information to be read even in low-light conditions. Such digital / electronic displays in watches, especially high-efficiency LCD displays, offer better contrast and readability during the day than similar digital displays equipped with backlight systems, because in the latter case, the digital display must be transflective to allow backlight to reach the observer, resulting in poorer optical quality during the day. The invention is particularly suitable for digital displays covered with structures (especially decorative structures) forming multiple display areas, with the lighting device comprising multiple LEDs or OLEDs arranged in front of these display areas for localized, simultaneous, or selective illumination of these areas.

Claims

1. A watch (2, 42) comprising: Display (12); watch face (6), the watch face being arranged above the display and having an effective area (9) through which the watch user can see the display; And an illumination device comprising at least one electroluminescent unit (14, 14a, 14b) disposed below the watch face and above the display, the electroluminescent unit being formed by at least one light source, the light source being, in particular, an LED or an OLED; characterized in that the at least one electroluminescent unit obtains power from peripheral contact areas (20a, 20b; 20c to 20f; 22g to 22j; 22g to 22k; 22p, 22n) via conductive pads (22a, 22b; 22c to 22f; 22g to 22j; 22g to 22k; 22p, 22n) made of a transparent conductive material, the peripheral contact areas being stacked axially. The conductive pads are arranged in a manner outside the effective area, with the conductive pads covering at least the entire lower portion of the effective area of ​​the mirror, except at a gap (26) separating the two conductive pads (22a, 22b) in the case of a single electroluminescent unit (14) having only two power contacts, or at multiple gaps (26a to 26d; 28) separating the conductive pads in the case of multiple electroluminescent units (14b) or a single electroluminescent unit (14a) having at least three power contacts; wherein each gap (26; 26a to 26d; 28) separates two adjacent conductive pads and has a width less than or substantially equal to two hundred micrometers.

2. The watch of claim 1, wherein, The width is less than one hundred micrometers.

3. The watch of claim 1, wherein, The width is less than fifty micrometers.

4. The watch according to any one of claims 1 to 3, characterized in that, In the case of a single electroluminescent unit (14) with only two power contacts, the two conductor pads (22a, 22b) each extend over almost half of the effective area (9) of the watch mirror.

5. The watch according to any one of claims 1 to 3, characterized in that, In the case of multiple electroluminescent units (14b) or one electroluminescent unit (14a) having at least three power contacts, the individual conductor pads (22d to 22f; 22h to 22j; 22h to 22k) in the conductor pads are configured such that each of the individual conductor pads has substantially the same resistance between the corresponding peripheral contact area (20d to 20f; 30b to 30d; 30b to 30e; 30n) and the corresponding power contact on the one or multiple electroluminescent units, each of the individual conductor pads being electrically connected to a single power contact associated with a single light source.

6. The watch of claim 5, wherein, A common conductor pad (22c; 22g; 22p) is configured to have a lower resistance than the individual conductor pads, and the common conductor pad is connected to multiple power contacts and / or associated with multiple light sources (14b) connected to the same power contact.

7. The watch according to claim 5 or 6, characterized in that The peripheral contact areas are arranged at intervals along the periphery of the watch face.

8. The watch according to claim 5 or 6, characterized in that The peripheral contact areas are arranged in a single connecting segment (29) that extends over less than a quarter of the perimeter (7), preferably over less than an eighth of the perimeter, wherein the peripheral contact areas are arranged in a row.

9. The watch according to any one of the preceding claims, characterized in that, The conductor pad is formed by a structured conductor layer (16) deposited on the lower surface (8) of the mirror (6); the at least one electroluminescent unit (14, 14a) is attached to the conductor pad.

10. The watch according to any one of claims 1 to 8, characterized in that, The conductor pad is formed by a structured conductor layer (16) deposited on the upper surface of the transparent substrate (44), and the at least one electroluminescent unit (14b) is attached to the conductor pad; the transparent substrate is glued to the lower surface (8) of the mirror (6) and covers the at least one electroluminescent unit.

Images