Abstract:
A light source is positioned to direct light downward from the cover of a conentional analog or electro-optical watch, indicator gauge, a meter panel directional gauge or ornamentation display of an image, logo or design or other similar articles. These articles are illuminated by the source for viewing in low light or in the dark by an illumination switch to activate said element. The light source is preferably an LED and it is small enough so that when it is off, it is virtually invisible.

Description:
This application is a continuation of Ser. No. 09/272,913 filed Mar. 19, 1999, now U.S. Pat. No. 6,106,127. 
    
    
     BACKGROUND OF THE INVENTION 
     A. Field of the Invention 
     This invention relates generally to an improvement in illuminated devices such as electronic timepieces equipped for a conventional analog or digital display, indicator gauges, which may comprises a meter panel, directional gauges, ornamentation displays of an image, logo or design, and other similar articles which are illuminated for viewing under poor lighting conditions. 
     B. Description of the Prior Art 
     Historically, watches, gauges and other similar articles were first illuminated by using phosphorescent markings. However, when both the manufacturing methods of phosphorescent materials and the materials themselves proved to be medically and environmentally unacceptable, other illuminating means were developed. Some of these other means include the use of LED, LCD, and fluorescent devices, as well as incandescent bulbs. All of these proved to be unsatisfactory, especially for small devices such as wrist watches. 
     Additionally, these devices could not provide sufficient illumination due to a non-uniformity in brightness across the illuminated display surface. The insufficient illumination was the result of the positioning or shape of the light source itself which was either a point or linear source thereby making these illumination devices limited and unacceptable. 
     Recently, electroluminescent lighting, hereinafter referred to as EL, was introduced, for an analog or digital watches as another known alternative. An EL element is positioned underneath the watch dials, or other surfaces, or alternatively the dials themselves are made of an EL material, as described in U.S. Pat. No. 3,749,977-Sliker, U.S. Pat. No. 4,775,964-Alessio &amp; Olsen, U.S. Pat. No. 4,208,869 Hanaoka, U.S. Pat. No. 5,029,046 Kamede U.S. Pat. No. 5,117,334 Kamede. In all of these references direct illumination is provided upward towards the viewer, restricting any aesthetic aspects such as a full color logo or colored images on the dial. Another disadvantage of EL&#39;s is that they require complicated auxiliary circuitry. Moreover, the lighting colors are determined by phosphorus contents of the EL, and are limited commercially to colors such as blue-green, white and yellow. 
     OBJECTIVES AND SUMMARY OF THE INVENTION 
     It is, accordingly, an objective of the present invention to eliminate the above-mentioned disadvantages encountered in the prior art and provide a system through which sufficient illumination can be provided to both indicia of interest as well as logos and other decorative elements. 
     It is another objective of the present invention to provide an illumination device for an electronic or analog timepiece, indicator gauge, directional gauge or ornamental device or other articles eliminating any EL as the illumination source and its associated circuitry. 
     Another objective of the invention is to provide an improved illumination apparatus for viewing the dial or surface of various objects by positioning an illumination device to direct light in a direction towards the subject to be illuminated which makes viewing easier, more efficient and less stressful to the viewer. 
     A further objective of this invention is to provide in situations such as limited lighting or at night time, the cosmetic illumination of single or multiple color images, logos or items located on or about the surface of a timepiece, indicator or directional gauges or ornamentation devices. 
     The present invention seeks to attain these objectives by disposing a light-emitting element, on or inside a light transmissive surface of the article to be illuminated. This element is positioned in the center, sides or in a random placement and rendered light emissive or is activated by means of an electronic circuit which is installed within or in proximity of said article. An illumination switch controlled by an external control member is provided on the case of the article for selectively activating the light emitting element. 
     More particularly, the light source is disposed either on an inner surface of, or is imbedded within the cover or article itself, in such a manner that is virtually invisible to the viewer. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood by reference to the following description, taken in connection with the appended drawings, in which like reference numerals indicate like parts, and in which: 
     FIG. 1 is a top view of an analog watch, with a light source positioned in the center of the inside surface of the watch cover pointing in a downward direction towards the dial; 
     FIG. 2 is a top view of one or more indicator or directional gauges, with a light source positioned in the center of the inside surface of the gauge&#39;s translucent or transparent cover and pointed in a downward direction towards the meter panel; 
     FIG. 3 is an enlarged top view of an ornamentation device with a light source positioned in the center of the ornamentation devices and pointing in a downward direction towards an image, logo or three dimensional or planar design; 
     FIG. 4 is a top view of a solid-state LED used as a light source for illumination as shown in FIGS. 1-3. 
     FIG. 5 is a cross-sectional view of the solid-state LED of FIG. 4; 
     FIG. 6 is a cross-sectional schematic view of the watch of FIG. 1; 
     FIG. 7 is a cross-sectional schematic view of the ornamentation of FIG. 3; 
     FIG. 8 is a cross-sectional view of the illumination pattern generated in for the watch of FIGS. 1 and 6; 
     FIG. 9 is a top view of the illumination pattern for the watch of FIGS. 1 and 6; 
     FIG. 10 shows a cross-sectioned view of a watch illustrating a second embodiment of the invention; 
     FIG. 11 shows a cross-sectional view of a watch illustrating a third embodiment of the invention; 
     FIG. 12 shows an enlarged view of the embodiment of FIG. 11 
     FIG. 13 shows a cross-sectional view of a watch illustrating a fourth embodiment of the invention: 
     FIG. 14 shows an enlarged view of the embodiment of FIG. 13; and 
     FIG. 15 shows a top view of the circuit board for the embodiment of FIGS.  13  and  14 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 and 6 illustrates a top view and a cross sectional view of an analog timepiece such as a wristwatch  1  with a conventional case  2  and with a minute hand  3  and an hour hand  4  mounted on rotatable stems  13  and driven by a conventional movement, the details of which are not material to the present invention and thereafter have been omitted. A button  5  is employed to set the position of the time hands  3  &amp;  4 . Push button actuators  6  &amp;  7  connected to operate switch contacts (not shown) inside the case of the watch. Actuators  6  and  7  may be used to actuate the subject light source, as well as to provide other optional functions. 
     Below the hands  3 ,  4  there is a dial  8  having time indicating indicia thereon, such as the hour and minute markers  9 , numerals  10  and an image or logo  11 . Importantly, dial  8  and all the indicia thereon are illuminated by one or more light sources  12  such as a light emitting diode, (herein referred to as an LED (described in more detail FIG.  4 ). In FIG. 1, source  12  is positioned at the geometric center of dial  8 . Alternatively, several such sources may be used which are distributed around the dial. Moreover, in the embodiment shown, the source  12  is mounted or secured to a bottom surface of a standard transparent or translucent cover  12 A covering and being coextensively with dial  8 . 
     FIG.  2 . shows a top view of an indicator gauge  100 , with a conventional case  102 , a meter panel  103 , with several indicator hands such as a fuel gauge hand  104  and a temperature gauge hand  105 . Below the hands are  104 ,  105  corresponding dials  106 ,  107  having measurement indicating indicia thereon, representing as the level of the fuel or temperature. The indicator gauge  100  may also be provided with a decorative or source identifying image or logo  108 . The indicator gauge  100  may be used, for example, on the dashboard of an automobile or any other system. 
     The dials  106 ,  107  and logo  108  are illuminated by a light source  109  such as an LED, again positioned in the center of case  102 . Alternatively, sources could be provided at several such as locations  110  and  111 . The source or sources are directed downward from cover  112 A. A push button actuator  112  connected to operate switch contacts (not shown) inside or within proximity of the indicator gauge  100 . 
     FIG. 3 shows a top view of an ornamentation device  201  which could be made from an injection molded transparent thermoplastic acrylic resin having a base  202 , a planar or  3 D image, or a logo or design  203 . The base  202  is covered by a protective cover  205 . Since the device  201  has no moving parts, the cover  205  could envelope the logo or design  203  so that there is no air contained therein. Alternatively, the device  201  maybe have liquid filled body with the logo or design  203  being disposed in the liquid. 
     Imbedded in solid body  205  there is provided a light source  204  such as an LED. Source  204  can be centrally located as shown. Alternatively several sources (not shown) may be provided for illuminating design  203  all pointing downward toward base  202 , and logo  203 . A push button actuator  206  could be connected or within proximity to operate switch contacts (not shown) inside or within proximity of the ornamentation device  201 . 
     Each of the sources of FIGS. 1,  2  and  3  maybe LED constructed and arranged as shown in FIG. 4 and 5. More particularly, each source includes a substrate  34 , a substrate  32  and a substrate  35 . These three substrates cooperate to form a standard light emitting diode. Typically substrate  34  may be about 10×10 mils while substrates  32  and  35  may be about 12×12 mils. The bottom surface (as oriented in FIG. 5) of substrate  35  is covered by a metallic layer  36  which forms the cathode for the diode. A portion of a top surface of substrate  34  is covered by a metallic layer  33  which defines the anode for the diode. Layer  33  may be for instance about 4×4 mils. Preferably layers  33  and  36  are made of gold. It should be understood the sources may be made using other types of technology besides LED&#39;s as well. 
     Two thin wires  37  and  38  are made of gold or aluminum are connected to the layers  33  and  36  respectively either directly or by resistors as shown. 
     Referring again to FIG. 6, source  12  is adhesively attached to the bottom or inner surface of cover  12 A. Stem  13  is a hollow coaxial cylindrical stem which drive the hands  3  and  4 . The wires  37 ,  38  pass through the stem  13  and extend to the source  12 . 
     Disposed below the dial  8  is a circuit board  14 , with an electronic control circuit  15 . Wires  37 ,  38  are connected to circuit  15 . A battery  16  is used to provide power to circuit  15  and source  12 . The circuit  15  (which may be an ASIC-application specific integrated circuit) is connected to an activator such as push-button actuator  6 . When the push-button actuator  6  is pushed, the source  12  is turned on. Alternatively, a timer may be built in to circuit  15  so that the source  12  remains on for a preselected time period. 
     FIG. 7 shows a cross-sectional view of the ornamentation  201 . In this Figure, source  204  is connected to an electronic circuit  311  and battery  312  by wires  37 ,  38 . The circuit  311  and battery  312  are disposed under the design or logo  203 , as shown. 
     FIGS. 8 and 9 show in a somewhat stylized how the source  12  generates light rays in a uniform and even manner to illuminate the entire dial  8 . As can be seen in these Figures, as will as in FIGS. 5 and 6, preferably source  12  does not have a focusing lens. 
     As previously mentioned, LED&#39;s with very high efficiency and various colors are now available and are ideally suited for as the subject light source. For example, a blue LED made of GaN with a SiC substrate can generate a 600 micro watt output at 430 nm peak wavelength. A green L.E.D. operated at 20-30 μ both a forward biasing voltage of 2V can generate 2.5—2.5 mcd. Superbright orange and red emitters are also available which can generate about 10 mcd at 630 nm with a power consumption of 70 mw. 
     In one embodiment of the invention, the sources  12 ,  204 , etc. are attached, for example by an adhesive, to the lower or inner surface of the respective protective covers  12 A,  112 A,  205 . In an alternate embodiment, instead of joining the source to the surface of the respective cover, the source can be imbedded directly into the cover. For example, as shown in FIG. 10, the timepiece  1  of FIGS. 1 and 6 is shown with a source  12 C which in this case is imbedded in cover  12 A. Wires  37 ,  38  can be led downward through the stem of the hands as in FIG. 6, or as indicated by the dashed lines, the wires could be arranged either on the bottom surface of the protective cover  12 A to extend laterally or radially to the case and then passed through the case to the battery  16  and circuit  15 , or they can also be imbedded into cover  12 A together with source  12 C. 
     Another embodiment of the invention is shown in FIGS. 11 and 12. In this embodiment, a watch  400  is provided with a cover  402 , hands  403 ,  404 , dial  405 , stem  406 , case  407 , and an electronic circuit  408 . (A separate battery has been omitted for the sake of simplicity). Importantly, watch  400  is further provided with a T-shaped structure  410  having a leg  411 , and two arms  412 ,  413 , terminating in light sources  414 ,  415 . 
     Structure  410  is cast or molded from a transparent, light but strong material such as a polymer. Imbedded in the structure  410  are wires  416  connecting light sources  414 ,  415  to electronic circuit  408 . Preferably, the structure  410  is positioned so that its leg  411  passes through stem  406  and its arms  412 ,  413  are disposed adjacent to a bottom surface  402 A of cover  402  as shown and supported by the leg  411  and/or stem  406 . If necessary, the arms  412  and  413  may be attached to the surface  402 A by a suitable adhesive. It should be understood that FIG. 11 shows structure  410  with two arms  412 ,  413 , however it can have any number of arms. Moreover, these arms can have the same length or may have unequal lengths. These arms have two functions; they support sources  414 ,  415  and they provide a means of supporting wires  416 . The ends of the arms are strategically positioned to provide proper illumination of the dial  405  by sources  414 ,  415 . 
     FIGS. 13 and 14 are similar to FIGS. 11 and 12 and show an alternate illuminating means. For these Figures, watch  500  is provided with a cover  501 , hands  502 .  503 , a dial  504 , a stem  506 , an electronic circuit  507  and a case  508 . In this embodiment one or more structures  510  are provided. Each structure  510  is L-shaped with a short vertical leg  512  and a long horizontal arm  514  terminating in a source  516 . Imbedded in arm  514  are a pair of wires  518  connecting source  516  to electronic circuit  507 . The wires from leg  512  pass through the dial  504  adjacent to case  508 . 
     Structure  510  is molded from a clear plastic material just like structure  410  and is supported in the position shown in the Figures by leg  510  as it passes through the dial  504 . The watch  500  can be provided with several structures  510 , arranged to position the sources  516  in a predetermined pattern on cover  501 . 
     The arm  514  may be made long enough to extend to stem  506  so that the source  516  is disposed at the center of cover  501 , if desired. The arm  514  is normally cantileveredly supported by leg  512 , but if necessary, it can also be adhesively attached to the inner surface  501  A of cover  501 . The structures  410 ,  510  are sized and shaped so that they are virtually invisible. 
     It should be understood that the light sources can be made into almost any color desirable. 
     Referring now to FIG. 15, circuit board  507  is formed with a central opening  521  and supports various electronic circuits such as  522  and  524  used to drive an analog stepping motor (not shown) operating the hands  502 ,  503  and/or the light sources  516 . The stem  506  passes through the opening  521  and is mechanically coupled to a knob  525  used to position the hands manually when required. 
     The circuit board  507  is also provided with two arcuate slots  526 ,  527 . Disposed within this slots are respective elastomeric members  530 ,  532 . 
     Also mounted on circuit board  507  are a plurality of contact pads  534 , each pad having two terminals  536 ,  537 . In FIG. 15 four pads are shown for a configuration wherein four corresponding structures  510  are provided. The pads  534  are arranged under each leg  512  of a corresponding structure  510 . In this position, each of the wires  518  within the structure  510  comes into electrical contact with one of the terminals  536 ,  537 . At least one of the terminals, such as terminal  536  on pad  534  is connected electrically to one of the corresponding elastomeric members  530 ,  532 . These members  530 ,  532  are arranged so that when they are pushed radially inwardly (for example by external knobs mounted on case  508  in the usual manner), they establish a contact with terminals  540  or  542 , thereby providing a control switch to operate selectively light sources  516  through the circuit  522 . 
     Obviously numerous modifications can be made to the invention without departing from its scope as defined in the appended claims.