Liquid crystal device for timepiece

Abstract

The invention relates to a liquid crystal device for a timepiece. The display device comprises a liquid crystal cell formed by two transparent plates, the liquid crystal cell defining a useful area designed to define a visible area of the cell in the timepiece, and the liquid crystal cell, in combination with electrodes, forming a switchable display of at least one item of information and / or at least one decoration in the useful area. A liquid crystal cell (LCD cell) includes a plurality of polarizers in a useful area, the polarizers are respectively arranged in a plurality of separation areas on an outer surface of one of two transparent plates, and the polarizers each partially form the switchable display. At least two polarizers of the plurality of polarizers have at least one different optical property or a different polarization direction therebetween, the timepiece display device is arranged to visually generate a change between at least respective portions of the at least two polarizers and / or respective portions of the switchable display in respective separation zones.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of manufacturing liquid crystal display devices (hereinafter also referred to as "LCD devices") for timepieces, and more generally to the field of manufacturing liquid crystal cells (hereinafter also referred to as "LCD cells") forming such LCD devices. BACKGROUND

[0002] Document EP 1 128 240 describes an electronic display assembly with contrast inversion formed by a liquid crystal display cell having electrodes and counter-electrodes defining switchable information segments and a light valve overlapping the display cell and formed by a liquid crystal cell having electrodes and counter-electrodes covering the entire useful area of the display cell so as to be able to continuously vary the contrast of the entire useful area of the display cell or to define a contrast of at least two electrodes and two corresponding counter-electrodes limiting at least two display areas complementary to the useful area, which can each present simultaneously a positive contrast (dark information on a light background) and a negative contrast (light information on a dark background). The display cell and the light valve comprise a first front polarizer and a second rear polarizer. The term "useful area" of the display cell or of the electronic display assembly is understood to mean the area designed to be seen by the user, in other words the visible area of the display cell or of the electronic display assembly once it has been incorporated into a timepiece.

[0003] Document EP 1 156 360 provides similar teachings as the preceding document, but is more complex in that it provides a display assembly with chromatic contrast inversion designed to be able to invert the color of the information displayed or of the background on which it appears when the electrodes of the display cell are activated (on state). To this end, an intermediate polarizer is also provided between the display cell and the light valve.

[0004] In order to achieve contrast inversion or to distinguish various display areas within the display assembly by varying the color of the respective background, the aforementioned display assemblies are complex and cumbersome. They are formed by two liquid crystal cells stacked on top of each other. However, it should be noted that it is useful to be able to distinguish between display areas by the color of the background (including white and black) and / or the shade of such color (in particular light or dark) and / or by the color of the information displayed to highlight some information or to make it stand out. In particular, this provides a visual contrast between the different display areas. Thus, in addition to the functional aspect, the separation of the various display areas in the LCD display assembly also provides an interesting aesthetic aspect, for example by visually separating the time display area from the date display area or the selected function. SUMMARY

[0005] The main object of the present invention is to provide a liquid crystal display device (LCD device) comprising an LCD cell for switchable display of at least one item of information and / or at least one ornament, and which defines various zones in the useful area of the LCD cell, at least two of said zones can be used for switchable display, and there is a visual change, in particular a colour difference (including white and black), or / and a difference in the shade of at least one colour (lighter or darker), and / or a different optical effect between said at least two zones, and / or a colour difference in the switchable display provided in these at least two zones. The object of the present invention is thus to visually distinguish said at least two zones, and / or the information or ornament that can be switched in these at least two zones, in the useful area of the LCD cell in an LCD display device, and to do so while occupying very little space, in particular without increasing the thickness of a conventional LCD cell forming such an LCD display device and with relatively little complexity.

[0006] To this end, the present invention provides a timepiece display device comprising a liquid crystal cell formed by a transparent first plate and a second plate, and a bead of glue joining the first plate and the second plate and defining with them an enclosed space containing liquid crystals, the liquid crystal cell defining in the bead of glue a useful area intended to define the visible area of the liquid crystal cell in a watch for which the display device is designed, and the liquid crystal cell incorporating electrodes (hereinafter including "electrode" and "counter-electrode") forming a switchable display of at least one item of information and / or at least one ornament in the useful area. The liquid crystal cell comprises in the useful area a plurality of polarizers arranged on the outer surface of the first plate in a plurality of separate zones, and each polarizer partially forming said switchable display. At least two polarizers of the plurality of polarizers then have at least one different optical property or different polarization direction between them, the timepiece display device being arranged to visually generate a change between the corresponding parts of said at least two polarizers and / or between the corresponding parts of said switchable display in the respective separate zones.

[0007] The present invention has the advantage of achieving the main object of the present invention using a single LCD cell, without additional light valves overlapping the LCD cell. In other words, the timepiece display device according to the present invention can comprise only one base assembly formed by two transparent plates joined by a bead of glue and defining between them a space containing liquid crystals. The display thus occupies very little space; in particular, it does not increase the thickness of the LCD display device used in a timepiece, and is relatively uncomplicated.

[0008] In a general embodiment, said at least two polarizers of the plurality of polarizers extend substantially in the same geometric plane.

[0009] In a first variant of the general embodiment, said at least two polarizers of the plurality of polarizers are juxtaposed and have respective profiles in which a portion of one polarizer runs parallel to a portion of the other polarizer.

[0010] In a second variant of the general embodiment, a first polarizer of said at least two polarizers of the plurality of polarizers has an opening in which a second polarizer of said at least two polarizers is located, the second polarizer having an outer profile running along the profile of the opening.

[0011] The general embodiment has the advantage of occupying very little space, since it does not increase the thickness of the conventional LCD cell of the timepiece display device when it is formed. BRIEF DESCRIPTION OF DRAWINGS

[0012] The application will be described in greater detail below with reference to the enclosed drawings given by way of non-limiting example, in which:

[0013] - Figure 1 is a cross-sectional view of the LCD cell along the section line I-I of Figure 2 the timepiece display device according to the first variant of the first main embodiment of the application;

[0014] - Figure 2 is a top view of the timepiece display device shown in Figure 1 ;

[0015] - Figure 3 is a cross-sectional view of the LCD cell forming the second variant of the first main embodiment;

[0016] - Figure 4 is a cross-sectional view of the LCD cell along the section line IV-IV of Figure 5 the timepiece display device according to the third variant of the first main embodiment;

[0017] - Figure 5 is a top view of the timepiece display device shown in Figure 4 ;

[0018] - Figure 6 is a cross-sectional view of the LCD cell similar to Figure 1 that of the first variant of the second main embodiment of the timepiece display device according to the application;

[0019] - Figure 7 is a cross-sectional view of the LCD cell forming the second variant of the second main embodiment;

[0020] - Figure 8 is a cross-sectional view of the LCD cell forming the third variant of the second main embodiment; and

[0021] - Figure 9 is a top view of a particular variant of the timepiece display device according to the application. DETAILED DESCRIPTION

[0022] Reference Figure 1 and Figure 2 An LCD unit 2 forming a first variant of a first main embodiment of a timepiece display device according to the application will be described.

[0023] The timepiece display device generally comprises a liquid crystal unit 2 formed by a first transparent plate 4, a second transparent plate 6 and a bead of glue 8 joining the first and second plates and defining with them an enclosed space containing liquid crystals 10. The liquid crystal unit defines within the bead of glue a useful area 12 intended to define the visible area of the unit in the watch for which the display device is designed, and it incorporates on the inner face of the first transparent plate 4 two sets of electrodes 34 and 36, and on the inner face of the second transparent plate 6 two sets of electrodes 35 and 37 facing and at least partially overlapping the sets of electrodes 34 and 36 respectively, so as to form in the useful area at least one switchable display 30 of an information item and / or of a decoration. It should be noted that "set of electrodes" is generally understood to mean "at least one electrode", and the reference is to the set of electrodes or to one or more electrodes of the set of electrodes. In the illustrated example, each set of electrodes comprises a plurality of electrodes defining segments for the conventional display of the digits "0" to "9" in an LCD timepiece display (each set of electrodes is represented by a continuous line in the various figures to simplify the figures). Figure 2 In the illustrated example, each set of electrodes comprises a plurality of electrodes defining segments for the conventional display of the digits "0" to "9" in an LCD timepiece display (each set of electrodes is represented by a continuous line in the various figures to simplify the figures).

[0024] According to the present application, the liquid crystal cell 2 comprises a plurality of polarizers in the active area 12, more specifically two polarizers 16 and 18 in the example shown in the figures, which are arranged in a plurality of separate areas, i.e. two separate areas 17 and 19 in the example shown, on the outer surface 5 of the first plate 4. Each of the electrodes 34 to 37 overlaps with the polarizers 16, 18 of the plurality of polarizers and with the polarizer 20 arranged on the outer surface 7 of the second transparent plate 6, such that they together form the switchable display 30. Further, in general, at least two polarizers of the plurality of polarizers, i.e. the two polarizers 16, 18 in the shown variants, each overlap with at least one pair of electrodes 34 and 35, respectively 36 and 37, which are arranged to form a part 30A, respectively 30B, of the switchable display 30 in the respective separate area 17, 19 in which the polarizer extends. It should be noted that in the example shown in the figures, each of the two polarizers 16, 18 thus overlaps with at least one pair of electrodes to form a part of the switchable display 30 in the respective separate area of the polarizer. In other words, each polarizer of the plurality of polarizers forms a part of the switchable display 30.

[0025] Then, in general, the at least two polarizers of the plurality of polarizers have at least one different optical property or different polarization direction between them and the LCD cell is arranged so as to visually generate a change in the timepiece display device between the respective parts of the at least two polarizers and / or between the respective parts of the switchable display in the at least two respective separate areas. In the shown example, the two polarizers 16 and 18 have a visual change between them in the display device, more specifically in the LCD cell 2, in combination with the oppositely arranged polarizer 20 on the outer surface of the second plate 6. Further, when the parts 30A and 30B of the switchable display are activated, these parts of the switchable display 30 also visually show a change in the respective separate areas 17 and 19.

[0026] In Figure 1 and Figure 2In the first variant illustrated, polarizers 16 and 18 are preferably rear polarizers arranged under the plate 4 which is a bottom plate, and polarizer 20 is a front polarizer, advantageously the only polarizer arranged on the outer face 7 of the second plate 6 which is an upper plate. Preferably, as illustrated, the single polarizer 20 extends over the entire useful surface 12 of the LCD cell 2, and advantageously slightly around the periphery of this useful surface. It should be noted that in a particular variant, the LCD cell 2 is inverted due to its arrangement in the watch, so that polarizers 16 and 18 are then front polarizers, and polarizer 20 is a rear polarizer. This particular variant is not preferred considering that a single-piece front polarizer extending over the entire useful surface 12 is aesthetically advantageous, since the gap between the rear polarizers is less visible to the user of the watch than the same gap between the front polarizers.

[0027] Then, in particular, the three polarizers 16, 18 and 20 are identical in material and are absorptive transmissive. The LCD display device is arranged over a transparent dial in the watch having a color different from the color of the polarizers, in particular over an analog display which can be at least partially visible through the LCD display device. However, polarizer 16 has a polarization direction in the LCD cell 2 which is orthogonal to the polarization direction of polarizers 18 and 20, which have the same polarization direction. Since the LCD cell is in this case of TN type, the separation zone 17 will have a relatively bright background (depending on the color of the dial), and the portion 30A of the analog display will have a positive contrast, with the overlapping and activated electrode pairs generating relatively dark segments. On the other hand, the separation zone 19 will have a relatively dark background, and the portion 30B of the analog display will have a negative contrast, with the overlapping and activated electrode pairs generating relatively bright segments (depending on the color of the dial). In this way, the zone 17 in the useful zone 12 makes it possible to always see through the LCD display device, in particular the analog display and the dial, what is underneath it, with only the activated segments of the switchable display masking this background. By contrast, the zone 19 in the useful zone 12 only allows seeing this background through the activated segments of the switchable display. It should be noted that, in order to increase the contrast, polarizer 18 is advantageously covered on its rear surface by a reflective film, as in the other variants which will be described below. In another arrangement of the watch, the LCD cell is arranged as a dial of an analog display, i.e. under the hands of this analog display. Although the arrangement of the LCD display device according to the application is advantageously incorporated into a watch with an analog display, the display device according to the application can also be incorporated into an electronic watch without an analog display.

[0028] In a first general variant, said different optical property between two polarizers is a color change.

[0029] In the second general variant, the different optical properties between the two polarizers are variations in hue for a given color; that is, variations in intensity.

[0030] According to a key feature of the main embodiment, at least two of the plurality of polarizers extend in substantially the same geometric plane, preferably in the same geometric plane 40. More generally, all of the plurality of polarizers extend in substantially the same geometric plane, preferably all in the same geometric plane 40.

[0031] According to a specific feature of the invention, a first polarizer of at least two of a plurality of polarizers has an opening, and a second polarizer of at least two of the plurality of polarizers is located in the opening, the second polarizer having an outer contour traveling along the contour of the opening. In the first variant described in this case, polarizer 16 has an opening 14 in which polarizer 18 is located, the size of which corresponds to the size of the opening. Thus, the outer contour of polarizer 18 travels along the contour of opening 14. The term "longer" is understood to have the standard dictionary definition, i.e., "traveling along and close to it, particularly parallel to it". The gap between the two contours that are parallel to each other is intended to be minimal, almost invisible or preferably invisible to the user. In the main embodiment, since the first polarizer and the second polarizer are arranged substantially in the same geometric plane and preferably in the same geometric plane, polarizer 18 is located inside the opening 14 of polarizer 16. To ensure that the gap is minimal and preferably invisible, a specific manufacturing method is required to position polarizer 16 very precisely relative to polarizer 18. For this purpose, target / guide marks can be provided on two transparent plates 4 and 6 (such as Figure 1 At least one of the transparent plates (above and below the adhesive beads 8) outside the useful area 12 is shown. When the polarizer is deposited on the outer surface of the transparent plate on which it is finally arranged, these target / guide marks are able to be precisely aligned with the polarizer and the alignment marks in a fixed and defined relationship.

[0032] exist Figure 1 and Figure 2 In the illustrated embodiment, four decorative annular portions 22, 23, 24, and 25 are also provided and arranged around the periphery of a polarizer 16 on the outer surface 5 of the base plate 4, the polarizer 16 having a circular outer contour. These decorative portions are arranged in the same geometric plane as the polarizers 16 and 18 (it should be noted that these polarizers and decorative annular portions are in...). Figure 2(Seen in a transparent view relative to the elements above them). Each decorative annular portion has an inner radius approximately equal to the radius of the polarizer 16. The inner contour of the decorative portion also extends along the outer contour of the polarizer 16, minimizing the gaps between these elements and preferably making them invisible to the user. These decorative portions can vary. In the first example, these are portions of a colored opaque film. In the second example, these are color filters that allow a certain amount of light to pass through, making it possible to see or distinguish the elements located below. It should be noted that in the first variation, the decorative portions are not polarizers because no switchable display is provided in the corresponding areas of these decorative portions. However, specifically for aesthetic reasons and to prevent the edges of the upper / front polarizer 20 from being visible, the upper / front polarizer also covers the decorative portions 22 to 25, as it extends over the entire useful surface 12 of the LCD unit 2. In the second variation, the decorative portions can be formed by polarizers. However, no electrodes facing these polarizers are provided, making them purely decorative. Conventionally, the polarizers and decorative portions are glued to the corresponding transparent plates.

[0033] Figure 3 A second variant of the first main embodiment is shown. Elements similar to the first variant will not be described again. The liquid crystal cell 42 includes a first transparent plate 4, which is the base plate of the LCD cell 42. Two polarizers 44 and 46 are arranged below this plate 4, with polarizer 46 having an opening 14A and polarizer 44 located within the opening 14A. Similar to the first variant, the outline / edge of polarizer 44 travels along the outline / edge of opening 14A. This second variant differs from the first variant in that the rear surface of polarizer 46 is covered by a reflective film 48. Furthermore, the second variant differs from the first variant in that the assembly formed by polarizer 46 and reflective film 48 has an embossed design that visually generates a periodic or other form of pattern visible to the user of the watch in which the LCD cell 42 is incorporated.

[0034] refer to Figure 4 and Figure 5 A description of the LCD unit 52 will be given here, which forms a third variant of the first main embodiment of the time display device according to the present invention. References already described will not be described here again.

[0035] In the third variant, at least two polarizers are typically provided side by side, with a portion of one polarizer running parallel to a portion of the other polarizer.

[0036] The phrase "two juxtaposed polarizers" is understood to mean that the two polarizers have profiles / edges such that a portion of the profile / edge of the first polarizer runs parallel to a portion of the profile / edge of the other polarizer. "Parallel" indicates that the portion of the profile / edge of one polarizer closely follows the portion of the profile / edge of the other polarizer, preferably substantially parallel. These two corresponding portions of the two profiles / edges may have a gap (small slit) between them, preferably almost imperceptible or imperceptible to the user of the display device according to the invention. In a particular variant, in the useful area 12, the profiles / edges of the juxtaposed polarizers are covered by a narrow masking strip, as will be explained below.

[0037] In a third variant, as shown, the LCD unit 52 includes a front polarizer 20A (particularly an absorber-transmitting polarizer) and three juxtaposed rear polarizers 54, 55, and 56 arranged in the same geometric plane 40. Whenever two or more polarizers are juxtaposed, this is understood to mean that each polarizer is juxtaposed with at least one other polarizer. Thus, in the variant shown, polarizers 54 and 55 are juxtaposed, with the two straight sections of their respective profiles parallel and very close together, or even practically merged (the edges defining these two straight sections may almost touch each other). The same is true for polarizers 55 and 56. Similarly, the front polarizer 20A extends through the useful area 12 and completely covers the rear polarizers 54, 55, and 56 within this useful area. The LCD unit 52 is used to form the dial of a watch with an analog display 66. The LCD unit 52 forms a disc pierced at its center for the axis of the analog display's hands to pass through, and the useful area 12 corresponds to the portion of the dial visible to the user of the watch, incorporating a display device including the LCD unit 52 within the watch. Therefore, the useful surface is an annular region with an outer limit 12A corresponding to the circle defined by the case flange on the LCD cell. The switchable display 50 includes three specific displays 50A, 50B, and 50C, which are formed by three polarizers 54, 55, and 56, respectively, of a plurality of polarizers arranged on the outer surface 5 of the transparent plate 4 and located in the three separation regions 57, 58, and 59 of the useful region 12. In the given example, the switchable display 50A displays the hours and minutes of the time interval measured in stopwatch mode, and the switchable display 50B displays the seconds and hundredths of a second of the measured time. The display 50C shows the date and month.

[0038] The reflective film 60 is disposed below and covers the three polarizers 54 to 56. The reflective film 60 is a single piece and is glued to the three polarizers in a step after the polarizers are glued to the outer surface 5 of the plate 4.

[0039] Advantageously, polarizer 54 has a different color than the two polarizers 55 and 56. In one variant, the back polarizer has various colors. A given color can also have different hues. Generally, each of the multiple polarizers can be formed by a single polarizing film or several polarizing films. In other words, each polarizer is formed by at least one polarizing film. Each polarizer can be combined with a color filter and / or a low-reflectivity and / or opaque film. In one variant, the lower surface of each polarizer is covered by its own reflective film having the same dimensions as the polarizer, and each polarizer is assembled with its own reflective film before being deposited onto the transparent plate 4. It should be noted that color filters can extend above or below the polarizers, individually or together above / below at least two polarizers, and particularly above / below all polarizers in a plurality of polarizers. It should be understood that numerous possible combinations are available to those skilled in the art, and various decorative variations with different color visual effects can be obtained for the background of the LCD unit and also for the elements of the switchable display.

[0040] The third variant also has a special feature, which can also be provided in other variants of the first embodiment, particularly in the first and second variants described above, and also in a variant of the second embodiment described below. This feature lies in masking the edges of the polarizers among a plurality of polarizers in the useful area, particularly when two polarizers are juxtaposed (first case) or when one polarizer is located inside an opening in another polarizer (second case), by covering these edges with an opaque material, and thus masking the contours of these polarizers in such a way that any possible gap between two corresponding portions of the two contours, where one contour is parallel to the other (in the first case), or any possible gap between the two contours, where one contour is parallel to the other (in the second case), is masked for the user of a watch for which a display device is designed. Figure 4 and Figure 5 In the variant shown, opaque material forms two straight masking strips 62A and 62B. In this variant, the transparent plate 4 is the base plate of the LCD unit 52, and the multiple polarizers 54 to 56 arranged on its outer surface are back polarizers (it should be noted that these polarizers and the masking strips are in...). Figure 5 (Seen in a transparent view relative to the element located above). In this case, opaque material is advantageously deposited on the outer surface 5 of plate 4 between plate 4 and the outline of the polarizer, the outline of the polarizer being covered by the opaque material in the useful area 12.

[0041] refer to Figure 6 The following section will describe the LCD unit 72, which forms a first variant of a second main embodiment of the time display device according to the present invention. Elements already described in the first embodiment will not be described in detail here.

[0042] In the useful area 12, as in the first embodiment, the LCD unit 72 includes a first plurality of polarizers 74 and 75 disposed on the outer surface 5 of the first transparent plate 4 and extending in the geometric plane 40. According to the general features of the second embodiment, in the useful area 12, the LCD unit 72 also includes a second plurality of polarizers 76 and 77, which are respectively disposed in a second plurality of separation areas 82 and 84 on the outer surface 7 of the second transparent plate 6. Generally, at least two of the second plurality of polarizers 76 and 77 have at least one different optical property or polarization direction between them. It should be noted that the switchable display area is shown in the first embodiment but is not referenced.

[0043] According to advantageous features, the second plurality of polarizers extend in approximately the same geometric plane, preferably in the same geometric plane 80 as in the example shown.

[0044] The first variant described herein has two specific features. First, the first polarizer 76 of the second plurality of polarizers has an opening 78, in which a second polarizer 77 of the second plurality of polarizers is located, the second polarizer having an outer contour that travels along the contour of the opening. According to the second specific feature, independent of the first specific feature, two polarizers 74, 75 of the first plurality of polarizers overlap with two polarizers 76, 77 of the second plurality of polarizers, respectively, and extend into the same corresponding separation regions 82 and 84 in the useful area 12. Polarizer 74 therefore has an opening having a contour aligned with the contour of the opening 78 of polarizer 76 in a direction orthogonal to the general plane of the LCD cell (parallel to geometric planes 40 and 80). Therefore, region 82 in the useful area 12 of the LCD cell 72 is independent of region 84 in the useful area, both in terms of the background and the switchable display.

[0045] refer to Figure 7 The following will describe a second variant of the second embodiment, which makes it possible to obtain an LCD display device having a plurality of zones that vary visually to the user and together form a relatively complex pattern that makes it possible to define the original decoration.

[0046] LCD unit 92 includes a first plurality of polarizers and a second plurality of polarizers. Each of the first plurality of polarizers, namely polarizers 94 and 95, partially defines a switchable display and is disposed on the outer surface of plate 4. In the illustrated example, plate 4 is a smaller plate. Each of the second plurality of polarizers, namely polarizers 96 and 97, also partially defines a switchable display and is disposed on the outer surface of plate 6. The first plurality of polarizers extend in geometric plane 40, and the second plurality of polarizers extend in geometric plane 80.

[0047] The second variant has two specific features. First, at least two polarizers 96 and 97 of the second plurality of polarizers are juxtaposed, each having a corresponding profile where a portion of one polarizer runs parallel to a portion of the other. Similarly, two polarizers 94 and 95 of the first plurality of polarizers are also juxtaposed. As a second specific feature, at least one first polarizer from the first plurality of polarizers partially overlaps only with at least one second polarizer from the second plurality of polarizers. More specifically, in the illustrated variant, polarizer 94 partially overlaps with polarizer 96 and partially overlaps with polarizer 97, and polarizer 95 partially overlaps with polarizer 96. Therefore, in the useful region, the profiles of the polarizers in the first plurality of polarizers are not aligned with the profiles of the polarizers in the second plurality of polarizers, such that the corresponding separation regions 104 and 105 of polarizers 94 and 95 do not overlap with the corresponding separation regions 106 and 107 of polarizers 96 and 97. Therefore, this configuration means that the separation region in geometric plane 40 relative to the arrangement of the first plurality of polarizers and the separation region in geometric plane 80 relative to the arrangement of the second plurality of polarizers produce a visually varied region than the number of polarizers in the first plurality of polarizers and the number of polarizers in the second plurality of polarizers.

[0048] In the variant shown, the reflective film 102 is arranged only below the polarizer 94, which serves as a back polarizer.

[0049] The LCD unit 92 also includes a decorative film 100 juxtaposed with polarizer 94 in a separation region of the lower geometric plane 40, and two decorative films 98 and 99 juxtaposed with polarizers 96 and 97, respectively, in two corresponding separation regions of the upper geometric plane 80. Alternatively, a single decorative film with an opening is provided in the upper geometric plane 80, in which polarizers 96 and 97 are located and together fill the opening. The decorative film is formed from a color filter, polarizer, or other film, and may be opaque or reflective and flat or raised. These decorative films do not contribute to the switchable display of the LCD unit 92, but they do contribute to the visual appearance of the LCD unit in the useful area 12 and visually distinguish the various areas within the useful area to define the composition of the decorative areas.

[0050] Figure 8A third variant of the second main embodiment of the invention is shown. This third variant differs from the second variant in that, in the useful area, the masking extends to the edges of polarizers 94 and 95 in the lower geometric plane and the decorative film 100, thus masking the outlines of these elements, each of which runs parallel to the other. The LCD unit 112 includes masking strips 114 and 115 formed of opaque material, as in the third variant of the first embodiment. This third variant then differs from the second variant in that, in the useful area, the masking extends to the edges of polarizers 96 and 97 and decorative films 98 and 99 juxtaposed in the upper geometric plane, the outlines of which each run at least partially parallel to the other in the useful area. For this purpose, the LCD unit 112 includes masking strips 116, 117, and 118 formed of opaque material deposited above the edges. Generally, the masking strip is formed of an opaque material that covers the outlines of the polarizers in the second plurality of polarizers, in order to mask any possible gaps between two corresponding portions of the two outlines, where one outline is parallel to the other, or between two outlines where one outline is parallel to the other, for the user designing the display device. In the example shown, considering that in addition to the polarizers in the second plurality of polarizers, there are decorative films arranged in the same upper geometric plane 80, the opaque material also covers the outlines of these decorative films in the usable area.

[0051] Figure 9This is a top view of a dial 120 formed by a display device according to the invention and including a liquid crystal cell 122. The LCD cell 122 is manufactured in a manner similar to that described in the first variant of the first or second embodiment, and additionally, the arrangement of the masking strips 132, 134, and 136 is as described in the third variant of the first or second embodiment. A plurality of polarizers are arranged in respective separation regions 124, 126, 128, and 130. At least one of the polarizers arranged in region 130 has three openings, wherein three polarizers are arranged, each polarizer having at least one optical property or polarization direction different from the polarizer with the three openings. The dial 120 is fitted to a watch having an analog display 66, which displays the current time in hours, minutes, and seconds. The switchable display of the LCD cell 122 is configured such that it can be used for the stopwatch function of the watch. Thus, the seconds, minutes, and hours of the timing intervals are displayed in separate circular regions 124, 126, and 128, respectively. In the separation zone 130, a symbol 138 related to at least one function of the watch (e.g., activation of the "Bluetooth" function or battery level) can be displayed. The letters "S", "M", and "H" can also be part of a switchable display and appear only when the stopwatch function is activated. This configuration is particularly advantageous when the switchable displays in zones 124, 126, and 128 are also intended for other information. In an alternative dedicated solely to the stopwatch function, these letters can be obtained using ink deposited on the dial or possibly in the LCD unit. In the example shown, zone 124 has a visual variation relative to zones 126 and 128; this variation can be a different color or a different shade of a given color (including gray). The switchable display portion in zone 124 is of positive contrast type, while the switchable display portions in zones 126 and 128 are of negative contrast type.

Claims

1. A timepiece display device comprising a liquid crystal unit (2, 42, 52, 72, 92, 112, 122), said liquid crystal unit being formed from a transparent first plate (4) and a second plate (4), and a glue bead (8), said glue bead being connected to and defining therewith an enclosed space containing liquid crystal (10), said liquid crystal unit defining a useful area (12) within said glue bead, which is intended to define a visible area of ​​said unit in a clock in which the display device is designed for use, and said liquid crystal unit in said useful area incorporating electrodes (34, 35, 36, 37; 34A, 35A, 36A, 37A) to form at least one information item and / or at least one decorative switchable display (30); characterized in that, The liquid crystal cell includes multiple polarizers (16, 18; 44, 46; 54, 55, 56; 74, 76; 94, 95) in the useful area (12), which are respectively arranged in multiple separation areas (17, 19) on the outer surface (5) of the first plate. 57, 58, 59; 104, 105), and each of them partially forms the switchable display; and wherein at least two of the plurality of polarizers have at least one different optical property or a different polarization direction between them, the time display is arranged to visually generate a change in the respective separation area at least between the respective portions of the at least two polarizers and / or between the respective portions of the switchable display.

2. The display device according to claim 1, characterized in that, The plurality of polarizers extend in approximately the same geometric plane (40).

3. The display device according to claim 2, characterized in that, At least two of the plurality of polarizers (54, 55, 56; 94, 95) are juxtaposed, and the two polarizers have a corresponding profile in which a portion of one polarizer runs parallel to a portion of the other polarizer.

4. The display device according to claim 2, characterized in that, The first polarizer (16, 48, 74) of the at least two of the plurality of polarizers has an opening (14, 14A), and the second polarizer of the at least two of the plurality of polarizers is located in the opening, the second polarizer having an outer contour that travels along the contour of the opening.

5. The display device according to claim 3 or 4, characterized in that, Opaque material (62A, 62B; 114, 115) covers the polarizer contours of the plurality of polarizers in order to mask any possible gaps between two corresponding portions of the two contours, one of which is parallel to the other, or between two contours, one of which is parallel to the other, for the user of the clock in which the display device is designed.

6. The display device according to claim 5, characterized in that, The first plate (4) is the base plate of the liquid crystal cell, and the polarizer among the plurality of polarizers is the rear polarizer of the liquid crystal cell.

7. The display device according to claim 6, characterized in that, The opaque material is deposited on the outer surface (5) of the plate between the first plate (4) and the edge of the polarizer, and the outline of the polarizer is covered by the opaque material.

8. The display device according to any one of claims 1 to 7, characterized in that, A single polarizer (20, 20A) is arranged on the outer surface (7) of a second plate (6), which is an upper plate, and the single polarizer is the front polarizer of the liquid crystal cell (2, 42, 52).

9. The display device according to claim 8, characterized in that, The single polarizer extends over the entire useful surface (12) of the liquid crystal cell.

10. The display device according to any one of claims 1 to 7, wherein, The plurality of polarizers are a first plurality of polarizers, and the plurality of separation regions are a first plurality of separation regions; characterized in that the liquid crystal cell (72, 92, 112) includes a second plurality of polarizers (76, 77; 96, 97) in the useful region (12), the second plurality of polarizers (76, 77; 96, 97) being respectively arranged in a second plurality of separation regions (82, 84; 106, 107) on the outer surface (7) of the second plate (6); and wherein at least two of the second plurality of polarizers have at least one different optical property or a different polarization direction between them.

11. The display device according to claim 10, characterized in that, The second plurality of polarizers extend in roughly the same geometric plane (80), and at least two of the second plurality of polarizers (96, 97) are juxtaposed, the two polarizers having a corresponding profile in which a portion of one polarizer runs parallel to a portion of the other polarizer.

12. The display device according to claim 10 or 11, characterized in that, The second plurality of polarizers extend in the same geometric plane (80); and the first polarizer (76) of the second plurality of polarizers has an opening (78), and the second polarizer (77) of the second plurality of polarizers is located in the opening (78), the second polarizer having an outer contour that travels along the contour of the opening.

13. The display device according to claim 11 or 12, characterized in that, Opaque material (116, 117, 118) covers the polarizer contours (96, 97) of the second plurality of polarizers in order to mask for the user of the clock in which the display device is designed to be used any possible gap between two corresponding portions of the two contours in which one portion runs parallel to the other portion, or any possible gap between two contours in which one contour runs parallel to the other portion.

14. The display device according to any one of claims 1 to 9, characterized in that, The difference in optical properties between the two polarizers is color change.

15. The display device according to any one of claims 10 to 14, characterized in that, The difference in optical properties between two polarizers in the second plurality of polarizers is color change.

16. The display device according to any one of claims 1 to 9, characterized in that, The difference in optical properties between the two polarizers is a change in hue.

17. The display device according to any one of claims 10 to 14, characterized in that, The different optical properties between two polarizers in the second plurality of polarizers are variations in hue.

18. The display device according to any one of claims 1 to 17, characterized in that, The first plate is the base plate of the liquid crystal cell; and wherein at least one of the plurality of polarizers is covered on its rear surface by a reflective film (60; 48; 102).

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