Abstract:
A timepiece has a faceplate that includes a liquid crystal display panel. The LCD panel has electrodes that may be arranged in sectors. The electrodes are driven so as to produce a dynamically changing sequence of patterns.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention is directed a timepiece, and particularly a watch, having dynamic ornamentation that is aesthetically pleasing and that draws attention to the watch.  
           [0002]    Most watches in use today are wristwatches. Their primary function is, of course, to display the time, either in a digital manner or in an analog manner (that is, using hands). Because they are very visible and are worn at the position of a bracelet, watches frequently also have a secondary function that is aesthetic in nature. There are several known ways to provide a watch with a pleasing, aesthetic quality. Perhaps the most familiar way is to design it as a piece of jewelry, basically equivalent to a bracelet, using precious metal and also possibly gemstones. Other techniques for improving the aesthetic qualities of a watch include designing it to have a rugged, masculine appearance, using colors that harmonize with different flesh tones or different wardrobes, and so forth.  
           [0003]    Digital watches generally employ liquid crystal displays or LCDs. Such displays use groups of image elements to display numbers, with each group having seven elongated segments that can be selectively activated to display a desired digit. Letters and other designations may also be displayed.  
           [0004]    Liquid crystal is an organic fluid which, despite being a fluid, has molecules which spontaneously assume an ordered configuration. This configuration can be altered by applying an electric field, and the resulting change in configuration of the molecules can be used to control light passing through the liquid crystal.  
           [0005]    A class of liquid crystals known as nematic liquid crystals is frequently used for making electrical displays. The liquid crystal is sandwiched between two polarizing plates bearing transparent electrodes made, for example, from metal oxide film (such as iridium tin oxide, or ITO). The polarization axis of light passing through the first polarizing plate is rotated by the liquid crystal if no voltage is applied between the electrodes, and the degree of rotation decreases or disappears entirely when a voltage is applied. As a result, light passing through the first polarizing plate and the liquid crystal may or may not pass through the second polarizing plate depending upon the applied voltage and hence the polarization axis of the light when it reaches the second polarizing plate. This arrangement can be back-lit, or illuminated from behind, or a mirror can be used to provide a reflective display that relies upon the ambient light. Instead of polarizing plates, transparent but non-polarizing plates can be used in conjunction with independent polarization layers.  
           [0006]    Since watches have both the useful function of telling the time and the aesthetic function of looking attractive or drawing attention, it is not surprising that the market for watches is fiercely competitive. Consequently, there is a continuing need for new techniques to improve the appearance of watches and to otherwise heighten their attention-drawing power.  
         SUMMARY OF THE INVENTION  
         [0007]    A primary object of the present invention is to provide a watch having a faceplate that is provided by an LCD panel and that presents a dynamically changing appearance so as to attract attention. The faceplate may be disposed behind the hands of a watch with an analog movement, or a region of the faceplate may be set aside for use as a time display region in a watch with a digital movement.  
           [0008]    Another object is to provide a faceplate using an LCD panel, with the electrodes on at least one side of the panel being divided into groups and with at least one of these groups being symmetrical with respect to at least one other group. All of the groups may be symmetrical. Alternatively, the first set of groups may be symmetrical with one another, the second set of groups may be symmetrical with one another, and so on for any further sets of groups.  
           [0009]    A further object is to provide a faceplate using an LCD panel in which electrodes on at least one side of the panel are grouped into symmetrical sectors, with wiring alleys being provided between the groups.  
           [0010]    Yet another object is to provide a watch having a faceplate using an LCD panel which is driven so as to display a series of display sequences in which image elements form patterns that appear to evolve.  
           [0011]    In accordance with one aspect of the invention, these and other objects which will become apparent from the ensuing detailed description can be attained by providing a watch that includes a watch case with a bezel mounted on it. An LCD panel is disposed below the bezel and has a visible area when viewed through the bezel. This visible area of the LCD panel has a maximum dimension (such as the diameter if the visible area is circular, the major axis if the visible area is elliptical, the length if it is rectangular, and so forth). The LCD panel includes a light-transmitting plate with first and second electrodes on it. The second electrode is electrically connected to the first electrode but is spaced apart from it by a distance that is at least as great as a fourth of the maximum dimension of visible area. Third and fourth electrodes are also disposed on the light-transmitting plate. The third electrode is spaced apart from the first and second electrodes by distances that are at least a fourth as great as the maximum dimension of the visible area. The fourth electrode is electrically connected to the third electrode but is spaced apart from it by a distance that is at least a fourth as great as the maximum dimension of the visible area.  
           [0012]    In accordance with another aspect of the invention, a watch includes an LCD panel with a light-transmitting plate. The LCD panel also includes a set of first electrodes disposed on the plate in a first sector, and a set of second electrodes disposed on the plate in a second sector. Each second electrode is paired with one of the first electrodes, and is electrically connected to it.  
           [0013]    According to yet another aspect of the invention, a watch has a faceplate that includes an LCD panel with a plate that transmits light, a set of first electrodes on the plate, and a set of second electrodes on the plate. The first electrodes are disposed at predetermined positions in a first sector, and have predetermined sizes and shapes. The second electrodes are disposed in a second sector that is symmetrical with the first sector. Each second electrode corresponds to one of the first electrodes, has substantially the same size and shape as the corresponding first electrode, and is located at a position within the second sector at a position that is substantially the same as the position of the corresponding first electrode within the first sector. Each second electrode is electronically connected to its corresponding first electrode.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 illustrates a watch having a faceplate in accordance with a first embodiment of the invention.  
         [0015]    [0015]FIG. 2 schematically illustrates mechanical and electrical features of the watch.  
         [0016]    [0016]FIG. 3 illustrates a top plate of an LCD panel in accordance with a first embodiment of the present invention, the top plate having a plurality of symmetrical sectors, with a predetermined number of electrodes in each.  
         [0017]    [0017]FIG. 4 illustrates the electrodes in one sector on the top plate, identified by different letters which indicate their positions within the sector.  
         [0018]    [0018]FIG. 5 illustrates electrical connections between the electrodes of two sectors of the top plate and a bus.  
         [0019]    [0019]FIG. 6 illustrates two sectors of electrodes on a bottom plate of the LCD panel, and how they are connected to a conductor.  
         [0020]    FIGS.  7 A- 7 F illustrates a short display sequence in which image elements provide a pattern that appears to evolve.  
         [0021]    [0021]FIG. 8 illustrates how FIGS. 8A and 8B fit together along a common dot-dash chain line to form a composite figure; and  
         [0022]    [0022]FIGS. 8A and 8B fit together to form a composite figure showing a light-transmitting plate and electrodes of an LCD panel for a watch in accordance with another embodiment of the invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]    A watch  10  in accordance with the present invention is shown in FIG. 1, and includes a case  12  having flanges  14  for attaching a watchband  16  to the case  12 . A bezel  18  is attached to the case  12 , and carries a transparent plastic window or so-called crystal (not numbered) that protects the hands of the watch. The watch&#39;s hands consist of a minute hand  20 , a second hand  22 , and an hour hand  24 . A watch stem  26  is shown in FIG. 1 in its retracted position. It can be moved outward to a withdrawn position and then rotated to set the hands of the watch, in the usual manner. Below the hands lies a watch face that comprises an LCD panel  28 . In FIG. 1 the panel  28  is shown in its quiescent or un-powered state.  
         [0024]    Turning now to FIG. 2, the watch  10  has a so-called “analog movement”  30  that is powered by a cell  32 . The analog movement  30  includes a motor  34  which is regulated by a motor drive circuit  36 . The motor  34  has a shaft  38  that supplies rotary power to a linkage or transmission mechanism  40 , which rotates the hands. The second hand  22  is rotated by way of a shaft  42  extending from the linkage mechanism  40 . The shaft  40  extends within and is rotatable with respect to a hollow inner cylinder  44 , which carries the minute hand  20  at its outer end. An outer cylinder  46 , surrounding the inner cylinder  44  and rotatable with respect to the cylinder  44 , carries the hour hand  24  at its outer end. The cylinder  46  extends through a hole  48  in the panel  28 . Although not shown, the panel  28  has a sealing agent at the periphery of the hole  48  and at the outer periphery of the panel  28  itself in order to keep the liquid crystal confined and to fix the elements of the panel  28  to one another.  
         [0025]    Analog movements suitable for use as analog movement  30  are commercially available.  
         [0026]    The watch  10  also includes a display controller  50 , which is powered by a battery  51  and which controls the display of the panel  28 . The controller  50  will be described in more detail later.  
         [0027]    In this embodiment, the LCD panel  28  is a reflective TN (twisted nematic) panel. As is known in the art, a reflective TN LCD panel typically has a stack of layers, including a transparent polarizing first plate (or a non-polarizing plate with an independent polarizer) carrying first transparent electrodes, a liquid crystal layer, a second transparent polarizing plate carrying second transparent electrodes, and a reflector. Light entering the panel via the first plate may or may not be reflected out of the panel by the reflector, depending upon whether voltages placed upon the first and second electrodes rotate the plane polarization of the light in such a manner that the light is blocked by the second polarizing plate. In the present embodiment, the electrodes carried by the first plate (which will hereafter be called the “top” plate) are arranged in a manner that will be described in more detail with reference to FIGS. 3 and 4.  
         [0028]    In FIG. 3, the top plate  52  is transparent, and the hole  48  is provided at its center. Electrodes are disposed in eight sectors with eight wiring alleys being provided between the sectors. In FIG. 3, the sectors are identified by reference numbers  54 - 68 . All of the wiring alleys are identified by the same reference number,  70 . The width of the wiring alleys  70  is exaggerated in FIG. 3 for the sake of convenient illustration.  
         [0029]    Each of the sectors has sixteen transparent electrodes (made, for example, from iridium tin oxide) that are generally triangular in configuration (the innermost triangles being truncated). Hereafter, the electrodes in each sector will be individually identified by letters A through P. To specify a particular electrode in a particular sector, the reference number identifying that sector will be used as a prefix, followed by the particular letter designating the electrode.  
         [0030]    The letters A-G will be used to designate the outer seven electrodes of a sector, progressing from A to G in the clockwise direction. One level inward, the next five electrodes are designated by the letters H through L, again in the clockwise direction. The three electrodes in the next level inward are identified by the letters N through  0 , in the clockwise direction. The innermost electrode (that is, the one closest to the hole  48 ) is identified by the letter P. How this system for identifying particular electrodes works is illustrated in FIG. 4 for the sixteen electrodes of sector  54 . It should be noted that the spaces between the electrodes are exaggerated, in FIG. 4 and several other figures, for the sake of convenient illustration.  
         [0031]    How the electrodes on the top plate  52  are connected in this embodiment is illustrated in FIG. 5. A sixteen-conductor bus  72  surrounds the eight sectors of electrodes. The individual conductors of the bus  72  will be identified by reference numbers  72 - 1  to  72 - 16 , from the innermost conductor to the outermost conductor, although only a few of the individual conductors are specifically marked with reference numbers in the drawing. The P electrodes of all eight sectors are connected to the conductor  72 - 1 . The N electrodes of all eight sectors are connected to conductors  72 - 2 . In a similar manner, the electrodes in all of the sectors that are identified by the same letter are connected to the same conductor of the bus  72 . Although FIG. 5 shows these connections using lines which extend into the interior of the electrodes and terminate in dots, this has been done for the sake of facilitating understanding of the invention and an ordinarily skilled person would appreciate that, in reality, the connections are accomplished by narrow films of ITO that extend from the peripheries of the electrodes. The bus  72  is connected to a further bus  74 .  
         [0032]    The LCD panel  28  also has a second or bottom plate  76 , a portion of which is shown in FIG. 6. In each of the eight sectors, the bottom plate  76  carries  16  generally-triangular transparent electrodes, all of which are identified by reference number  78  in FIG. 6. The electrodes  78  in each sector are connected to a conductor  80  which surrounds the eight sectors of the bottom plate  76 . The conductor  80  is, in turn, connected to a conductor  82 . The electrodes  78  carried by the bottom plate are disposed directly below electrodes A-P carried by the top plate  52 .  
         [0033]    Returning, now, to FIG. 2, the display controller  50  includes a sequence controller  84  and an LCD driver circuit  86 , which are preferably fabricated as a single IC. The sequence controller  84  includes a pulse generator  88 , which generates a pulse stream having a predetermined frequency (such as about one pulse per second) and supplies these pulses to a counter  90 . The counter  90  counts pulses up to a predetermined number (such as 1024, or 2 10 ) and then resets itself to 0. The output of counter  90  is a binary number that is provided to a ROM as address signal for the ROM. At each address, the ROM  92  stores a sixteen-bit word that is supplied to the sectors of the LCD panel  28  by way of the bus  74 .  
         [0034]    Referring next to FIGS. 2 and 5 together, it is the sixteen-bit words stored in the ROM  92  that determine which of the electrodes A-B in the 8 sectors are activated so as to make an image element visible. These image elements are the visual manifestations of the electrodes A-P when the electrodes are activated. The bits of the words stored in ROM  92  could be selected randomly, so that sequence controller  84  would essentially be a pseudo-random number generator which supplies a pseudo-random number at the predetermined pulse frequency (e.g., about once per second). However, it is also possible to select the bits of the words stored in ROM  92  so that the image elements displayed during one second are usually related in some way to the image elements displayed during the next second, for sequences ranging from a few seconds to many seconds. In this way, the overall impression imparted by the LCD  28  appears to evolve, during the course of a few-to-many second display sequence. Such an evolving display sequence, coupled with the eight-way symmetry provided by the eight sectors, imparts an impression that is similar to an optical kaleidoscope.  
         [0035]    An example is illustrated in FIGS. 7A through 7F, which show a display sequence having six display intervals (each, for example, about a second long in duration). In FIG. 7A, the P electrodes on the top plate  54  are activated, thereby providing a ring of image elements, as shown, in the first interval of the display sequence. In FIG. 7B, the N electrodes are activated. The relation to what is shown in the prior display interval (FIG. 7A) is that the N electrodes lie adjacent the P electrodes. In addition to the N electrodes, the M and the O electrodes are activated in FIG. 7B.  
         [0036]    In FIG. 7C, the N-O electrodes remain activated, and also the D and J electrodes. FIG. 7D is the same as FIG. 7C, except that the N electrodes have been deactivated. The D and J electrodes remain activated in FIG. 7E, but the M and  0  electrodes have been deactivated. Additionally, the I and K electrodes have been activated in Figure E.  
         [0037]    Finally, in FIG. 7F, the D electrodes remain activated but the I-K electrodes have been deactivated. Additionally, the B and F electrodes, on either side of the D electrodes, have been activated.  
         [0038]    It will be apparent that the display sequence illustrated in FIGS.  7 A- 7 F does not convey an impression of mere randomness. Instead, there appears to be an overall theme in this display sequence, with at least one of the display elements during each display interval being related in some way with at least one display element during the next display interval (as by continued activation of the same electrodes or adjacent electrodes). The overall impression imparted by the display sequence shown in FIGS.  7 A- 7 F might be described as a general outward movement, with the ring shown in FIG. 7A growing larger in FIG. 7B and then evolving into more complex but still ring-based images in FIGS. 7C and 7D. These complex images, which have expanded outward from the simple rings shown in FIGS. 7A and 7B, then morph into outward-moving triangles in FIGS. 7E and 7F.  
         [0039]    Another embodiment of the present invention will now be described with reference to FIGS. 8A and 8B, which fit together to form a composite drawing as shown in FIG. 8. In this second embodiment, an LCD panel includes a light-transmitting plate  94  having a hole  96  for passage of the shaft  42  and cylinders  44  and  46  (see FIG. 2) of the analog movement  30 . Attached to the plate  94  are electrodes that are shaped as circles, ellipses, and hearts. These electrodes have different sizes and orientations. The electrodes are disposed in eight sectors, identified as sectors  98 ,  100 ,  102 ,  104 ,  106 ,  108 ,  110 , and  112 . Serpentine wiring alleys  214  (depicted in the drawing using broad back lines) are provided between the sectors. The twelve electrodes in each sector are connected to a twelve-conductor bus (not shown) corresponding to the bus  72  shown in FIG. 5. The letters A through L have been used in FIGS. 8A and 8B to identify electrodes that are connected to the same conductor of this bus, and thus to each other. For example, the innermost electrodes are labeled “A” (that is, an elliptical electrode in sector  98 , a small circular electrode in sector  100 , a large circular electrode in sector  102 , a medium circular electrode in sector  104 , a medium heart-shaped electrode in sector  106 , a medium circular electrode in sector  108 , an elliptical electrode in sector  110 , and a small heart-shaped electrode in sector  112 ), and are all connected to the same conductor of the bus. Similarly, all of the electrodes identified with the letter B are connected to the same conductor of the bus, and so forth for the remaining electrodes.  
         [0040]    It will be apparent from FIGS. 8A and 8B that some of the electrodes that are connected together via the bus (such as the electrodes labeled L in sectors  98  and  106 , or the electrodes labeled I in these sectors) are separated by considerable distances. Typically, the bezel  18  (see FIG. 1) would overlap the periphery of plate  94 , thus permitting a viewing area of the LCD panel that is somewhat smaller in expanse than the plate  94  itself. In the example shown in FIGS. 8A and 8B, the distances between the L electrodes in sectors  98  and  106  would be a substantial percentage of the diameter of the viewing area through the bezel.  
         [0041]    The LCD panel in this embodiment can be driven by a display controller similar to the display controller  50  shown in FIG. 2. However, the words stored in the ROM  92  would need only 12 bits, instead of 16 as in the first embodiment, in order to specify which of the twelve electrodes in each sector should be activated during each display interval.  
         [0042]    Numerous modifications can be made in the embodiments described above without loss of the amusement value provided by the watch  10 , and such modifications are intended to be included within the scope of the appended claims. Some of these modifications will be mentioned below.  
         [0043]    Although the watch  10  employs an analog movement, it would be possible to use a digital movement instead. With such a modification, a portion of the LCD panel  28  would be configured to display digits. The overall effect would be a window displaying digits representing the current time, with the window being superimposed on or embedded in a decorative region displaying a changing sequence of image elements.  
         [0044]    Another modification would be to use a back-lit LCD panel instead of the reflective LCD panel  28 . A further modification would be to use a filter to color the backlighting, or to use a liquid crystal of a type that inherently imparts color, or to tint the plate  52 .  
         [0045]    If a transmission LCD panel is used instead of a reflective one, it can be located above the hands of an analog watch instead of below the hands.  
         [0046]    The LCD panel  28  need not be a TN panel. Other types of liquid crystal can be used (for example, STN [super-twisted nematic] or HTN [high-performance twisted nematic]).  
         [0047]    Instead of eight sectors, more than eight sectors or fewer than eight sectors may be used. The number of electrodes in each sector is not limited to the sixteen electrodes A-P used in the first embodiment or the twelve electrodes marked A-L used in the second embodiment. A greater number or lesser number may be used.  
         [0048]    In the first embodiment described above, for example, all of the A electrodes are activated simultaneously, all of the B electrodes are activated simultaneously, and so on for the remaining electrodes. With reference to the arrangement shown in FIG. 5, this is achieved by connecting all of the A electrodes to the same conductor in the bus  72 , all of the B electrodes to the same conductor of the bus  72 , and so forth. This provides eight-fold symmetry. However, a more complex arrangement could be achieved by connecting the A electrodes in every other sector to the same conductor and, in the sectors that were skipped over, connecting the B electrodes to this conductor. The remaining A and B electrodes could then be connected to some other conductor of the bus  72 . Similarly, half of the C and D electrodes could be connected to the same conductor of bus  72  and the other half could be connected to another conductor, and so on for the remaining electrodes. Another possibility for modification would be to use inverters to invert the activation signals supplied to the electrodes of every other sector.  
         [0049]    Although FIG. 2 shows only one ROM  92  and FIG. 5 shows only one bus  72 , this arrangement could be modified by connecting the bus  72  to only half of the segments, adding another bus that is connected to the other half, and adding another ROM to store values that are conveyed via the added bus.  
         [0050]    The watch  10  may have switches, not shown in FIGS. 1 and 2, to select the operating speed of the LCD panel (such as either about one frame per second in a slow mode or about five frames per second in a fast mode) or to deactivate the LCD panel.  
         [0051]    The watch  10  need not have a circular face. For example, it can be rectangular or oval. In such a case, some of the sectors may have more electrodes than other sectors, or the sizes of the electrodes and possibly also their shapes may be adjusted so as to accommodate the same number of electrodes in each sector.  
         [0052]    The electrodes of the LCD panel are preferably configured to have decorative shapes. The decorative shapes are not, of course, limited to the specific examples disclosed with respect to the first and second embodiments described herein. Other suitable shapes include rectangles, regular polygons, card suites (spades, hearts, diamonds, and clubs), arrowheads, monetary designations (such as dollar signs, cent signs, yen signs, euro signs, and British pound signs), symbols denoting the zodiac, Xs, astronomical symbols (such as the sun or Sol, stars, ringed or ringless planets, comets, and the moon in a crescent state), silhouettes of clouds, silhouettes of plants such as three or four leaf clovers or flowers, silhouettes of animals such as soaring birds, arcs or rainbows, and smiley-faces. This list is not exhaustive, of course, and other decorative shapes can also be used.