Patent Publication Number: US-6987710-B2

Title: Alarm clock with dial illumination

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This patent application is a non-provisional application of prior U.S. provisional patent application Ser. No. 60/387,989, filed on Jun. 12, 2002, and is a continuation-in-part application of U.S. patent applications “Clocks Having Diffusion Reflector Lighting”, Ser. No. 10/304,329, filed on Nov. 26, 2002 and Ser. No. 60/334,428, filed on Nov. 30, 2001, the rights of priority of which are hereby claimed for this patent application. 

   BACKGROUND OF THE INVENTION 
   This invention generally relates to clocks having multiple features including unique lighting and time display features. More particularly, a preferred embodiment of the invention relates to illumination of the dial of the clock, which may be associated with a night light feature that may be activated and deactivated automatically in response to ambient lighting conditions, or that may be activated and deactivated manually by a user-operated switch. 
   Various types of alarm clocks are known to the prior art, including analog alarm clocks with hands to indicate the current time and digital clocks with digits to display the current time. Some analog alarm clocks also include certain illumination features to assist in reading the time under the low level lighting conditions usually encountered during the evening hours. However, such analog alarm clocks with illumination do not provide sufficient illumination to also provide night lighting for the room in which the clock is located. 
   Particularly in a battery-powered alarm clock, the illumination of the clock needs to be efficient since the amount of the current drain on the batteries is inversely related to the life of the batteries. 
   There is therefore a need for an analog alarm clock with an illumination system that efficiently converts light from a light source into illumination for the dial of the alarm clock for easy viewing of the displayed time, and that also provides dispersed lighting into a room to serve as a night light. 
   Also needed is an analog alarm clock that automatically activates the illumination features when the ambient lighting falls below a predetermined threshold and that automatically deactivates the illumination features when the ambient lighting rises above a predetermined threshold. 
   An analog alarm clock with illumination features that may be varied by the user to his/her preferences is also desirable. 
   It is therefore a general object of the present invention to provide an improved alarm clock with an illumination module to efficiently provide illumination of the face of the clock and to provide sufficient light dispersion out of the illumination module for night lighting of the room in which the clock is located. 
   A further object of the present invention is to automatically activate the illumination features when the ambient lighting falls below a predetermined threshold, and to automatically deactivate the illumination when the ambient lighting rises above a predetermined threshold. 
   Yet another object of the present invention is to provide the capability for the user to manually control the illumination features of the alarm clock to his/her desired illumination characteristics. 
   Another object of the present invention is to provide an improved alarm clock with an LED light source that is positioned in an edge of the illumination module. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to various illumination features for an alarm clock of the analog type with hands to display the time. The illumination may be automatically activated in response to low ambient lighting conditions, such as encountered during the evening hours, and may be automatically deactivated when normal ambient lighting conditions return in the morning hours. A light sensor is used to detect the ambient lighting levels. The illumination may alternatively be manually controlled by a user-operated switch. A dimmer control adjusts the amount of illumination provided by the illumination module. 
   A light illumination module, such as a light emitting diode (LED), in combination with a light reflector, is disposed either in front of, or behind, the clock dial to provide uniform lighting of the dial of the clock and to also provide sufficient light dispersion out of the light module for night lighting of the room in which the alarm clock is located. The light illumination module is preferably of ovate shape, with an enlarged end that has one or more recesses defined therein to receive one or more light sources, such as LEDs. This enlarged end of the illumination module, with the recesses and light sources, typically extends beyond the normal viewing area of the dial of the clock, and is hidden from view by the frame or housing of the clock. 
   For best light transmission and dispersion from the light sources to illuminate the dial of the clock and to provide night lighting in the room, the illumination module is preferably transparent, such as of clear acrylic plastic, with the edges of the module having reflective properties, such as provided by reflective coatings or paint. However, the edges of the recesses, in which the light sources are disposed, are clear for receiving illumination from the light sources into the illumination module. 
   The illumination module is typically positioned behind the dial. The dial is clear or translucent except for the time or other indicia on the dial and the back surface of the illumination module may be coated with a generally opaque reflective coating, or have a reflective material disposed behind the illumination module, such as plastic sheet material, foils, or the like. Such sheet material or foils may be embossed, engraved, imprinted by silk screen techniques, or the like, to enhance light dispersion in and out of the illumination module. If the illumination module is disposed in front of the dial, the back surface of the illumination module will be clear to see the indicia on the dial, and the dial will be generally opaque and reflective to reflect and disperse illumination about the dial and out of the illumination module to provide night lighting. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with the further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, in the several figures in which like reference numerals identify like elements, and in which: 
       FIG. 1  is a front elevational view of an AC powered alarm clock with ambient light sensing for automatic activation and deactivation of the lighting functions in accordance with the invention. 
       FIG. 2  is a rear elevational view and partial bottom plan view of the alarm clock illustrated in  FIG. 1 . 
       FIG. 3  is a side elevational view of the alarm clock illustrated in  FIGS. 1 and 2 . 
       FIG. 4  is a cross-sectional view of the alarm clock illustrated in  FIGS. 1–3  taken along the sectional line  4 — 4  of  FIG. 2 . 
       FIG. 5  is a pictorial diagram of an alarm switch for the alarm clocks in  FIGS. 1–4  and  6  illustrating the different positions thereof. 
       FIG. 6  is a cross-sectional view, similar to the cross-sectional view of  FIG. 4 , but for a battery powered alarm clock, with ambient light sensing for automatic activation and deactivation of the lighting functions. 
       FIG. 7  is a front elevational view of an illumination module with a single light source for use in the alarm clocks illustrated in  FIGS. 1–4  and  6 . 
       FIG. 8  is a side elevational view of the illumination module illustrated in  FIG. 7 . 
       FIG. 9  is a cross-sectional view of the illumination module of  FIGS. 7 and 8  taken along the sectional line  9 — 9  of  FIG. 7 . 
       FIG. 10  is a front elevational view of an illumination module with two light sources for use in the alarm clocks illustrated in  FIGS. 1–4  and  6 . 
       FIG. 11  is a front elevational view of an alarm clock with manually controlled activation and deactivation of the illumination functions in accordance with the invention. 
       FIG. 12  is a pictorial diagram of an alarm switch for the alarm clock in  FIG. 11  illustrating the various positions thereof. 
       FIG. 13  is a front elevational view of an illumination module for use in the alarm clock illustrated in  FIG. 11 . 
       FIG. 14  is a side elevational view of the illumination module illustrated in  FIG. 13 . 
       FIG. 15  is a cross-sectional view of the illumination module of  FIGS. 13 and 14  taken along the sectional line  15 — 15  of  FIG. 13 . 
       FIG. 16  is a front elevational view of an illumination module with two light sources for use in the alarm clock illustrated in  FIG. 11 . 
       FIG. 17  is a dot matrix pattern that may be employed in the reflector of the clocks illustrated in  FIGS. 1–4 ,  6  and  11 . 
       FIG. 18  is an alternative dot matrix pattern that may be used in the reflector of the clocks illustrated in  FIGS. 1–4 ,  6  and  11 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to the Figures, and particularly to  FIG. 1 , a clock, generally designated  20 , is constructed in accordance with the invention. Clock  20  is of the analog type with hands, such as an hour hand  22 , a minute hand  23  and a second hand  24 , for indicating the time. Clock  20  also has an alarm time hand  21  for indicating the time of the alarm setting. 
   Clock  20  may be powered from a common AC outlet. An AC plug  25  is suitable for insertion in an AC outlet, and a line cord  26  electrically connects the clock  20  with the plug  25 . As seen in  FIG. 4 , the clock  20  may also be provided with a back-up battery  31  contained within a battery compartment  32  that is accessible by a battery door  33 . Back-up battery  31  supplies operating power to clock  20  during temporary AC power outages, and may be of the alkaline type, such as the commonly available AA size. 
   Clock  20  has a housing including a front housing portion  28  and a rear housing portion  29  ( FIGS. 1–3 ). In addition to the shapes depicted in the drawing figures, housing portions  28  and  29  can be supplied with other ornamental features or be configured into other ornamental shapes, as desired. Wood and/or metal accents could also be utilized. Housing portions  28  and  29  can also be fabricated from different materials. For example, to satisfy the tastes of consumers, housing portions  28  and  29  could be different colors of plastic. As one example, the housing portions  28  and  29  may be formed from a thermoplastic, as by injection molding. The front and rear housing portions  28  and  29  may snap fit together by means of techniques well-known in the plastic molding arts. 
   As seen in  FIG. 4 , a generally transparent lens  27  may engage the front housing portion  28  to enclose and to protect the time indicating hands  21 – 24  from damage, and to keep dust and contaminants from accumulating in the interior of clock  20 . Lens  27  may be formed, for example, from a transparent plastic material. Most of the visible portion of lens  27  may be generally flat as shown in  FIGS. 3 and 4 , or any other suitable or ornamental shape. 
   Clock  20  has a face or dial  35  which has disposed thereon a plurality of time-indicating numerals, such as the numeral “10” at  36 . The “NIGHT VISION” mark and logo shown on the dial  35  are trademarks of Equity Industries Corp. 
   With reference to  FIGS. 1–4 , clock  20  has a generally flat base  37  suitable for standing clock  20  on a desk, night stand, dresser, table, or the like. 
   As seen in  FIG. 4 , clock  20  has a movement  38  adapted to move the time indicating hands  22 – 24 . Movement  38  is preferably of the quartz type for excellent time accuracy. Shafts of the movement  38  extend through apertures, such as an aperture  39  in a reflector  40 . 
   A plurality of knobs is provided on the back side of the clock  20 , as seen in  FIG. 2 , to enable the user to set the clock  20 . A clock set knob  41  can be rotated, as indicated in  FIG. 2 , to initially set the time for clock  20  by moving the hour and minute hands,  22  and  23 , respectively. An alarm set knob  43  can be rotated to move alarm time hand  24  to the desired alarm time. A dimmer knob  43  can be rotated to set the dial illumination to any desired level between low and high positions. 
   An alarm activation switch  45  is disposed near the top of the clock  20 . Alarm switch  45  slides between two positions as illustrated in  FIG. 5 . In the down or retracted position, the alarm function for clock  20  is turned off, as illustrated in depiction  46  of  FIG. 5 . In the up or raised position, as illustrated in depiction  47  of  FIG. 5 , the alarm function is activated. When sliding up or down, switch  45  engages electrical contacts located on an adjacent printed circuit board  48  ( FIG. 4 ). 
   An alarm clock  50  is illustrated in  FIG. 6 . Clock  50  is another embodiment of clock  20 . Clock  50  operates from a pair of batteries  51  within a battery compartment  52  that is accessible through a battery door  53 . For example, batteries  51  may be of the alkaline type in the commonly available C size. Some consumers, such as travelers, prefer a battery-operated clock since it does not need resetting when removed from luggage, or the like. Otherwise, clock  50  is similar to clock  20 . 
   There are, of course, other alternatives to alkaline batteries. Rechargeable batteries could be used in place of the alkaline batteries. The front of clock  50  could also incorporate one or more solar cells to provide operating current for the clock during the daylight hours, with the batteries  51  acting as back-up power during the evening hours. Such solar cells could also use any excess power capacity to recharge the rechargeable batteries during the day. 
   In accordance with one aspect of the present invention, an illumination module illustrated in  FIG. 7 , consisting of a light emitting diode (LED)  55  in combination with a light reflector  40 , provides lighting for the dial  35  of the clock  20  or  50  under dim lighting conditions typically found in homes or offices after sunset. LED  55  and reflector  40  also provide sufficient light dispersion to function as a night light in unlit or dimly lit rooms. 
   Disposed near the top edge of reflector  40  is a light sensor  57 , such as a photoelectric cell, as shown in  FIG. 7 . Light sensor  57  continually senses the light level of the room in which clock  20  or  50  is located. When the ambient light level falls below a predetermined threshold, light sensor  57  causes LED  55  to be electrically energized by a power source to activate illumination from LED  55  for clock  20  or  50 . Similarly, if the ambient light level rises above a predetermined threshold, light sensor  57  causes LED  55  to be electrically disconnected from the power source to deactivate any illumination. The light sensor  57  can be disposed in the aperture  58  defined near the top edge of reflector  40 . 
   Dial  35  is in front of, and generally overlies the reflector  40 . For good light transmission therethrough, dial  35  is generally transparent, except for the generally opaque time-indicating numerals  36  and other indicia, as the trademark Night Vision. 
   The light illumination module including LED  55  and reflector  40  is better seen in  FIGS. 7–9 . With reference to  FIG. 7  first, when the dial  35  is of generally circular configuration, as in the embodiment illustrated in  FIGS. 1–4 , the reflector  40  is preferably of generally ovate shape. That is, a portion of reflector  40  extends below the circular dial  35  for enclosing LED  55  in a recess  56  formed in the reflector  40 . In this example, recess  56  is of generally U-shape in the bottom edge of reflector  40 , and LED  55  is disposed in the U-shaped recess  56 . Recess  56  and LED  55  are out of view when observing the face of the clock. 
   The optical properties of reflector  40  contribute significantly to the efficiency of the light module to illuminate the dial  35  and to provide sufficient illumination from clock  20  or  50  for night light capability. Reflector  40  is ideally transparent and may be formed from a clear acrylic plastic material. As seen in  FIG. 8 , the edge periphery of the reflector  40  is coated with an optically reflective and opaque coating such that light from LED  55  is reflected back into the interior of the reflector from all angles. This optically reflective coating may be, for example, a white paint. The front side of reflector  40  that abuts the dial  35  in  FIG. 4  is uncoated and transparent for light transmission therethrough. However, portions of the front side of reflector  40  that are not visible from the front of the clock, such as those portions designated  59  on either side of LED  55  are also optically coated for maximum light reflectivity from LED  55  into the central area of reflector  40 . 
   The back side of reflector  40  is also preferably coated to provide a light reflective surface. Light dispersion from the reflector  40  through the dial  35  and into the room in which the clock  20  or  50  is located is also desired to provide a night light function. 
   LED  55  is preferably disposed within a recess or notch, such as in the U-shaped recess  56  defined in the periphery of reflector  40 , such that virtually all of the light emitted by LED  55  is gathered and transmitted by the reflector  40 . 
   Clock  20  or  50  may, of course, be provided with more than one LED. Shown in  FIG. 10  is a reflector  60  with two U-shaped recesses  61  and  62  suitable for provision of two LEDs  63  and  64 , with one LED in each recess. LEDs  61  and  62  preferably provide different color light for enhanced lighting effects in clock  20  or  50 . LEDs  61  and  62  may also indicate different clock conditions. For example, LED  61  may be of a yellow color to indicate normal functioning of clock  20  or  50 , and LED  62  may be of a red color to indicate low battery capacity, to indicate that batteries  51  should be replaced. 
   It will be apparent that many alternatives exist to the described structure for clock  20  or  50 . For example, instead of a separate dial  35  with the time indicia  36  disposed in front of the reflector  40  or  60 , these two elements could be combined by printing the time indicia  36  on the back side of reflector  40  or  60  prior to coating the back side of reflector  40  or  60  with the reflective coating. Yet another example is that one enlarged recess could be provided for each LED  63  and  64  in the reflector design of  FIG. 10  instead of the two recesses  61  and  62  for separately containing the two LEDs  63  and  64 . 
   Shown in  FIG. 11  is a third embodiment of a clock, generally designated  70 , constructed in accordance with the invention. In many respects, clock  70  is similar in structure to clocks  20  and  50 . However, it will be noticed that clock  70  does not have a light sensor, such as light sensor  57  for clocks  20  and  50 , disposed near the top of the dial  35 . The dial illumination for clock  70  is manually activated and deactivated by a user-operated switch  71 . As shown in the depictions of  FIG. 12 , switch  71  is movable between three positions. When switch  71  is fully down, as in depiction  72  of  FIG. 12 , both the alarm and illumination functions are off. In the intermediate position illustrated in depiction  73 , the illumination function is on, but the alarm function is off. In the uppermost position of switch  71  illustrated in depiction  74 , both the alarm and illumination functions are on. 
   Clock  70  may be primarily AC powered with battery back-up, as clock  20 , or entirely battery powered, as clock  50 . Of course, manual control of the illumination function, as by switch  71  in clock  70 , can extend battery life by terminating the illumination function when not needed. As with clocks  20  and  50 , dimmer knob  43  may be used to vary the level of illumination to any desired level between maximum and minimum levels. 
   Illustrated in  FIG. 13  is a reflector  80  for the clock  70  which utilizes one LED  81  disposed in a U-shaped recess  82 . Note, however, that reflector  80  does not have an aperture  58  for a light sensor  57 . Thus, LED  81  may alternatively be disposed along a top edge of reflector  80  since there is no aperture  58  or light sensor  57  adjacently disposed to the LED  81  that could interfere with some paths of light transmission from the LED  81 . 
   The structure and operation of the reflector  80 , as shown in  FIGS. 14 and 15 , is similar to the structure and operation of the reflector  40  shown in  FIGS. 8 and 9 , except for the absence of the light sensor  57  disposed in the aperture  58  of reflector  40 . 
   Illustrated in  FIG. 16  is an alternative illumination module, including two LEDs  91  and  92  each disposed in a respective U-shaped recess  93  and  94 . Other than the absence of the light sensor  57 , reflector  90  and its associated LEDs  91  and  92  will operate similarly to the prior description of the dual-LED reflector  60  in  FIG. 10  for clocks  20  and  50 . 
   Other variations may be made to the design of the various reflectors  40 ,  60 ,  80  and  90  shown in  FIGS. 7 ,  10 ,  13  and  16 , respectively. For example, instead of the previously described reflective coating on the back sides of these reflectors, a reflective surface could be disposed along the back side of these reflectors  40 ,  60 ,  80  or  90 , such as metal foil, colored plastic sheet materials, or the like. 
   The back side of reflectors  40 ,  60 ,  80  or  90  could alternatively be engraved to provide multiple raised surfaces, such as points, bumps, protuberances, or the like.  FIGS. 17 and 18  illustrate surfaces,  95  and  96 , respectively, created by dot engraving techniques. Such rough surfaces result in increased dispersion of light from the dial  35  of the clocks  20 ,  50  and  70  to provide more efficient night light capability. Use of engraving techniques can also provide more interesting backgrounds as seen through the dial  35  of the clocks  20 ,  50  and  70 , including textures, decorative designs, decorative patterns, or the like. If a plastic sheet material or a metal foil is used on the back side of reflectors  40 ,  60 ,  80  or  90 , as described above, such sheet materials or foils may also be embossed with textures, designs or patterns. Silk screen techniques may also be employed to imprint patterns, textures or designs on the back sides of reflectors  38 ,  48  or  78 , or upon any sheet materials or foils disposed on or against the back sides of the reflectors. 
   Illumination modules, such as reflectors  38 ,  48  and  78 , also have utility in providing lighting in other applications. For example, these illumination modules may also be used to provide illumination of street numbers for homes, businesses and apartments. Similarly, these illumination modules can provide illumination for mailboxes, light posts and the like. They can also provide background illumination for advertisements, signs, information panels and the like. For example, signs that are typically illuminated include emergency, exit and entrance signs in public buildings. 
   It will be understood that the embodiments of the present invention that have been described are illustrative of some of the applications of the principles of the present invention. Various changes and modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.