Patent Publication Number: US-11644361-B2

Title: Eyewear with detection system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/703,805, filed Dec. 4, 2019, now U.S. Pat. No. 11,326,941, and entitled “EYEWEAR WITH DETECTION SYSTEM,” which is hereby incorporated by reference herein, and which is a continuation of U.S. patent application Ser. No. 16/426,351, filed May 30, 2019, now U.S. Pat. No. 10,539,459, and entitled “EYEWEAR WITH DETECTION SYSTEM,” which is hereby incorporated by reference herein, and which is a continuation of U.S. patent application Ser. No. 16/102,859, filed Aug. 14, 2018, now U.S. Pat. No. 10,359,311, and entitled “EYEWEAR WITH RADIATION DETECTION SYSTEM,” which is hereby incorporated by reference herein, and which is a continuation of U.S. patent application Ser. No. 15/343,472, filed Nov. 4, 2016, now U.S. Pat. No. 10,060,790, and entitled “EYEWEAR WITH RADIATION DETECTION SYSTEM,” which is hereby incorporated by reference herein, and which is a continuation application of U.S. patent application Ser. No. 14/313,989, filed Jun. 24, 2014, now U.S. Pat. No. 9,488,520, entitled “EYEWEAR WITH RADIATION DETECTION SYSTEM,” which is hereby incorporated by reference herein, and which is a continuation application of U.S. patent application Ser. No. 12/322,377, filed Feb. 2, 2009, now U.S. Pat. No. 8,770,742, entitled “EYEWEAR WITH RADIATION DETECTION SYSTEM”, which is hereby incorporated herein by reference, and which is a continuation application of U.S. patent application Ser. No. 11/078,855, filed Mar. 11, 2005, now U.S. Pat. No. 7,500,746, entitled “EYEWEAR WITH RADIATION DETECTION SYSTEM”, which claims priority to: (i) U.S. Provisional Patent Application No. 60/562,798, filed Apr. 15, 2004, entitled “EYEWEAR WITH ULTRAVIOLET DETECTION SYSTEM,” and which is hereby incorporated herein by reference; (ii) U.S. Provisional Patent Application No. 60/583,169, filed Jun. 26, 2004, entitled “ELECTRICAL COMPONENTS FOR USE WITH EYEWEAR, AND METHODS THEREFOR,” and which is hereby incorporated herein by reference; (iii) U.S. Provisional Patent Application No. 60/592,045, filed Jul. 28, 2004, entitled “EYEGLASSES WITH A CLOCK OR OTHER ELECTRICAL COMPONENT,” and which is hereby incorporated herein by reference; (iv) U.S. Provisional Patent Application No. 60/605,191, filed Aug. 28, 2004, entitled “ELECTRICAL COMPONENTS FOR USE WITH EYEWEAR, AND METHODS THEREFOR,” and which is hereby incorporated herein by reference; (v) U.S. Provisional Patent Application No. 60/618,107, filed Oct. 12, 2004, and entitled “TETHERED ELECTRICAL COMPONENTS FOR EYEGLASSES,” which is hereby incorporated herein by reference; (vi) U.S. Provisional Patent Application No. 60/620,238, filed Oct. 18, 2004, entitled “EYEGLASSES WITH HEARING ENHANCED AND OTHER AUDIO SIGNAL-GENERATING CAPABILITIES,” and which is hereby incorporated herein by reference; (vii) U.S. Provisional Patent Application No. 60/647,836, filed Jan. 31, 2005, and entitled “EYEGLASSES WITH HEART RATE MONITOR,” which is hereby incorporated herein by reference; and (viii) U.S. Provisional Patent Application No. 60/647,826, filed Jan. 31, 2005, and entitled “EYEWEAR WITH ELECTRICAL COMPONENTS,” which is hereby incorporated herein by reference. 
     In addition, this application is related to: (i) U.S. patent application Ser. No. 10/822,218, filed Apr. 12, 2004, now U.S. Pat. No. 7,792,552, and entitled “EYEGLASSES FOR WIRELESS COMMUNICATIONS,” which is hereby incorporated herein by reference; (ii) U.S. patent application Ser. No. 10/964,011, filed Oct. 12, 2004, now U.S. Pat. No. 7,192,136, and entitled “TETHERED ELECTRICAL COMPONENTS FOR EYEGLASSES,” which is hereby incorporated herein by reference; (iii) U.S. patent application Ser. No. 11/006,343, filed Dec. 7, 2004, now U.S. Pat. No. 7,116,976, and entitled “ADAPTABLE COMMUNICATION TECHNIQUES FOR ELECTRONIC DEVICES,” which is hereby incorporated herein by reference; and (iv) U.S. patent application Ser. No. 11/078,857, filed Mar. 11, 2005, and entitled “RADIATION MONITORING SYSTEM,” which is hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     It is common for people to be exposed to various types of radiation. Often excessive exposure to radiation can be hazardous to one&#39;s health. One type of radiation that frequently raises a health concern is ultraviolet (UV) radiation. UV radiation is subdivided into three types: UV-A, UV-B, and UV-C. UV-C radiation has wavelengths in the range of 200 to 285 nanometers (nm) and is totally absorbed by the earth&#39;s atmosphere. UV-B, from about 285 to 318 nm, is known to cause skin cancer in humans. UV-A, from about 315 to 400 nm, is mostly responsible for tanning. However, UV-A has also been found to play some role in skin cancer and is the cause of eye cataracts, solar retinitis, and corneal dystrophies. 
     Although several UV radiation measuring and warning instruments have been developed and made commercially available, these instruments are disadvantageous for various reasons. One disadvantage is that the instruments are often a stand alone, special purpose device. As a result, a user must separately wear the special purpose device, which can be intrusive and often inconvenient. Another disadvantage is that those instruments, even if separate but attachable to other devices, hinder or impede the design for the devices. 
     Thus, there is a need for improved approaches to measure and inform persons of UV radiation levels. 
     SUMMARY OF THE INVENTION 
     Eyewear having monitoring capability, such as for radiation or motion, is disclosed. Radiation, such as ultraviolet (UV) radiation, infrared (IR) radiation or light, can be measured by a detector. The measured radiation can then be used in providing radiation-related information to a user of the eyewear. Motion can be measure by a detector, and the measured motion can be used to determine whether the eyewear is being worn. 
     In one embodiment, the invention pertains to eyewear having radiation monitoring capability. Radiation, such as ultraviolet (UV) radiation, infrared (IR) radiation or light, can be measured by a detector. The measured radiation can then be used in providing radiation-related information to a user of the eyewear. Advantageously, the user of the eyewear is able to easily monitor their exposure to radiation. 
     In one embodiment, all components for monitoring radiation can be integrated with the eyewear, such as the frame (e.g., a temple of the frame) of the eyewear. Since any of the components provided can be integrated with the eyewear, the disturbance to design features of the eyewear can be reduced. As an example, the eyewear normally includes a pair of temples, and the components for monitoring radiation can be embedded within one or both of the temples. In one implementation, all components for monitoring radiation are integrated into a temple of the frame of the eyewear. As an example, these components can be formed together on a substrate as a module. 
     In one embodiment, the eyewear includes a detector, electrical circuitry and an output device. The eyewear can also include one or both of a battery and a solar cell to provide power to the electrical circuitry and possibly other components. Further, the eyewear can also include one or more additional sensors. Still further, the eyewear can also include communication capabilities. 
     The invention can be implemented in numerous ways, including as a system, device, apparatus, and method. Several embodiments of the invention are discussed below. 
     As eyewear, one embodiment of the invention can, for example, include at least: a frame including at least a first temple and a second temple; a radiation detector for sensing an amount of radiation; and an electronic circuit operatively connected to the radiation detector. The electronic circuit provides at least radiation information based on at least the amount of radiation sensed by the radiation detector. The radiation detector and the electronic circuit are at least partially internal to the first temple of the frame. 
     As eyewear, another embodiment of the invention can, for example, include at least: a frame including at least a first temple and a second temple; a radiation detector for sensing an amount of radiation; and an electronic circuit operatively connected to the radiation detector. The electronic circuit provides at least radiation information based on at least the amount of radiation sensed by the radiation detector. The radiation detector includes at least an optical filter for reducing passage of predetermined undesired radiation therethrough, and a photodetector for sensing at least a portion of radiation that passes through the optical filter. The photodetector and the electronic circuit are internal to the frame. Further, the frame has an opening adjacent the optical filter to allow at least a portion of the radiation that passes through the optical filter to impinge on the photodetector. 
     As a consumer product for monitoring radiation, one embodiment of the invention can, for example, include at least: a radiation detector for sensing an amount of radiation; and an electronic circuit operatively connected to the radiation detector. The electronic circuit provides at least radiation information based on at least the amount of radiation sensed by the radiation detector. The radiation detector and the electronic circuit are at least partially embedded in the consumer product. The radiation being detected by the radiation detector is principally solar radiation from the sun. The consumer product can also be wearable by a user. 
     Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG.  1    is a perspective view of UV monitoring glasses according to one embodiment of the invention. 
         FIGS.  2 A and  2 B  are diagrams of a circuit board according to one embodiment of the invention. 
         FIG.  3    is a block diagram of a UV monitoring system according to one embodiment of the invention. 
         FIG.  4 A  is a block diagram of a UV monitoring system according to another embodiment of the invention. 
         FIG.  4 B  is a block diagram of a UV monitoring system according to still another embodiment of the invention. 
         FIG.  4 C  is a block diagram of a UV monitoring system according to yet another embodiment of the invention. 
         FIG.  4 D  is a block diagram of a UV monitoring system according to yet another embodiment of the invention. 
         FIG.  5    is a chart that depicts examples of auxiliary sensors that can be utilized as the one or more auxiliary sensors shown in  FIGS.  4 A- 4 D . 
         FIG.  6    is a block diagram of a UV monitoring system according to one embodiment of the invention. 
         FIG.  7 A  is a schematic diagram of a UV monitoring circuit according to one embodiment of the invention. 
         FIG.  7 B  is a schematic diagram of a UV monitoring circuit according to another embodiment of the invention. 
         FIG.  7 C  is a schematic diagram of a UV monitoring circuit according to yet another embodiment of the invention. 
         FIG.  7 D  is a schematic diagram of a UV monitoring circuit according to still yet another embodiment of the invention. 
         FIG.  8    is a flow diagram of a UV monitoring process according to one embodiment of the invention. 
         FIG.  9    is a flow diagram of a UV monitoring process according to another embodiment of the invention. 
         FIG.  10    is a flow diagram of a UV monitoring process according to yet another embodiment of the invention. 
         FIG.  11    is a flow diagram of a UV monitoring process according to still yet another embodiment of the invention. 
         FIG.  12    is a block diagram of electronic circuitry according to one embodiment of the invention. 
         FIG.  13 A  is a schematic diagram of an electronic circuit for a UV detection system according to one embodiment of the invention. 
         FIG.  13 B  is a schematic diagram of a periodic supply voltage circuit according to one embodiment of the invention. 
         FIG.  14 A  is a block diagram of a radiation monitoring system according to one embodiment of the invention. 
         FIG.  14 B  is a block diagram of a radiation monitoring system according to another embodiment of the invention. 
         FIG.  14 C  is a schematic diagram of a radiation-to-frequency converter according to one embodiment of the invention. 
         FIG.  14 D  is a schematic diagram of a latch according to one embodiment of the invention. 
         FIG.  14 E  is a schematic diagram of a LCD driver according to one embodiment of the invention. 
         FIG.  14 F  is a schematic diagram of a power supply according to one embodiment of the invention. 
         FIG.  14 G  is a cross-sectional view of a UV detector arrangement according to one embodiment of the invention. 
         FIG.  14 H  is a cross-sectional view of a UV detector arrangement according to one embodiment of the invention. 
         FIG.  14 I  is a cross-sectional view of a UV detector arrangement according to one embodiment of the invention. 
         FIG.  14 J  is a partial block diagram of a radiation monitoring system according to one embodiment of the invention. 
         FIG.  14 K  is a schematic diagram of a radiation-to-frequency converter and a sensor according to one embodiment of the invention. 
         FIG.  14 L  is a diagram of a representative waveform of a low duty cycle signal V D . 
         FIG.  14 M  is a schematic diagram of a power supply another according to one embodiment of the invention. 
         FIG.  14 N  is a diagram of a binary counter according to one embodiment of the invention. 
         FIG.  14 O  is a block diagram of latch-driver circuitry according to one embodiment of the invention. 
         FIG.  14 P  is a block diagram of driver circuitry according to one embodiment of the invention. 
         FIG.  14 Q  is a block diagram of driver circuitry according to another embodiment of the invention. 
         FIG.  14 R  is a block diagram of a radiation monitoring system according to another embodiment of the invention. 
         FIGS.  15 A- 15 C  are cross-sectional diagrams of a radiation detection systems according to different embodiments of the invention. 
         FIG.  16 A  is a cross-sectional view of an eyewear housing containing a radiation detection system according to one embodiment of the invention. 
         FIG.  16 B  is a cross-sectional view of an eyewear housing containing a radiation detection system according to another embodiment of the invention. 
         FIG.  16 C  is a cross-sectional view of an eyewear housing containing a radiation detection system according to still another embodiment of the invention. 
         FIG.  16 D  is a cross-sectional view of an eyewear housing containing a UV detection system according to yet still embodiment of the invention. 
         FIG.  16 E  is a cross-sectional view of an eyewear housing containing a radiation monitoring system according to one embodiment of the invention. 
         FIG.  17 A  is a cross-sectional view of a module housing according to one embodiment of the invention. 
         FIG.  17 B  is a cross-sectional view of an eyewear housing according to one embodiment of the invention. 
         FIG.  18    is a cross-sectional view of an eyewear housing having a reflective-type filter according to one embodiment of the invention. 
         FIG.  19    is a side view of a temple for an eyeglass frame according to one embodiment of the invention. 
         FIGS.  20 A and  20 B  are top view diagrams of a portion of an eyeglass frame according to one embodiment of the invention. 
         FIG.  21    is a side view of a temple for an eyeglass frame according to one embodiment of the invention. 
         FIG.  22    is a side view of a temple for an eyeglass frame according to another embodiment of the invention. 
         FIGS.  23 A- 23 G  illustrate examples of various end products having radiation monitoring capability. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Eyewear having monitoring capability, such as for radiation or motion, is disclosed. Radiation can be measured by a detector. The measured radiation can then be used in providing radiation-related information to a user of the eyewear. Motion can be measured by a detector, and the measured motion can be used to determine whether the eyewear is being worn. 
     In one embodiment, an electronic circuit having radiation monitoring capability. Radiation, such as ultraviolet (UV) radiation, infrared (IR) radiation or light, can be measured by the electronic circuit. The measured radiation can then be used in providing radiation-related information to a user of the electronic circuit 
     In one embodiment, all components for monitoring radiation can be integrated with eyewear, such as a frame (e.g., a temple of the frame) of the eyewear. Since any of the components provided can be integrated with the eyewear, the disturbance to design features of the eyewear can be reduced. As an example, the eyewear normally includes a pair of temples, and the components for monitoring radiation can be embedded within one or both of the temples. In one implementation, all components for monitoring radiation are integrated into a temple of the frame of the eyewear. As an example, these components can be formed together on a substrate as a module. 
     In one embodiment, the eyewear includes a detector, electrical circuitry and an output device. The eyewear can also include one or both of a battery and a solar cell to provide power to the electrical circuitry and possibly other components. Further, the eyewear can also include one or more additional sensors. Still further, the eyewear can also include communication capabilities. 
     In another embodiment, some or all of the components for monitoring radiation can be partially or completely tethered to the eyewear. In still another embodiment, some or all of one or more auxiliary sensors used therewith could be partially or completely tethered to the eyewear. Tethering components allows for increased design freedom with the eyewear as well as additional area with which to house the components. 
     The eyewear can contain lenses, either vision corrective lenses or non-corrective lenses. Examples of eyewear using corrective lenses include, for example, prescription glasses, bi-focal glasses, reading glasses, driving glasses, and progressive glasses. Examples of eyewear, using corrective or non-corrective lenses, are sunglasses, fit-over glasses, safety glasses, sports glasses, swim masks or goggles and ski goggles. The eyewear can also include wrap-around glasses (with wrap-around lenses), fit-over glasses, or auxiliary frames (which attach to existing frames). Still further, the eyewear can include a strap for glasses, such as a strap to hold glasses on one&#39;s head. The strap can include some or all of the components for monitoring radiation, such components can be attached or at least partially embedded in the strap. 
     Embodiments of the invention are discussed below with reference to  FIGS.  1 - 23 G . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments. Although much of the discussion below pertains to monitoring of UV radiation, it should be understood that the invention is also applicable to other types of radiation (infrared, x-rays, etc.). 
       FIG.  1    is a perspective view of UV monitoring glasses  100  according to one embodiment of the invention. The UV monitoring glasses  100  include a frame and a pair of lenses  102 . The frame has lens holders  104  that hold the lenses  102  in position. The frame also has a bridge  106 . The UV monitoring glasses  100  also include a pair of temples (or arms)  108 . The temples  108  are considered part of the frame. As shown in  FIG.  1   , each of the temples  108  is coupled to the frame by a hinge  109 . In one embodiment, the temples  108  can be removed from the frame. At least one of the temples  108  includes an internal cavity  110 . Within the internal cavity  110  is a circuit board  112 . The circuit board  112  can serve as a substrate. The circuit board  112  can have or couple to a solar cell  114  and UV detector  116  which are also at least primarily provided within the internal cavity  110 . The circuit board  112  could include a battery (not shown) in addition to or alternative to the solar cell  114 . The temple  108  having the cavity region  110  includes an opening  118  for the solar cell  114  (if provided) and an opening  120  for the UV detector  116 . In addition, the circuit board  112  can further include or couple to circuitry  122  and a display device  124 . For example, the display device  124  can be either a liquid-crystal display (LCD) or a Light-Emitting Diode (LED) display having one or more LED components, either of which can be controlled by the circuitry  122 . The solar cell  114  can receive light via the opening  118  so as to provide power to the circuit board  112 . The UV detector  116  can receive light via the opening  120 . The UV detector  116  is used to provide an indication of UV radiation. The indication of UV radiation detected by the UV detector  116  can be processed by the circuitry  122  to produce an output at the display device  124 . 
       FIGS.  2 A and  2 B  are diagrams of the circuit board  112  according to one embodiment of the invention. In one embodiment, the circuit board includes at least one electronic component. 
       FIG.  2 A  shows a first side of the circuit board  112 . Typically, the first side would be positioned adjacent a top side or outer side of the temple  108 . As shown in  FIG.  2 A , the first side of the circuit board  112  has the solar cell  114  and the UV detector  116  attached thereto. The first side of the circuit board  112  should be exposed at least partially to external light (e.g., sunlight). Hence, the openings  118  and/or  120  of the temple  108  shown in  FIG.  1    can provide openings so that light can impinge upon the solar cell  114  and the UV detector  116 . 
       FIG.  2 B  shows a second side of the circuit board  112 . The second side of the circuit board  112  can be a bottom side or inner side of the temple  108 . As shown in  FIG.  2 B , the second side of the circuit board  112  can have the circuitry  122  and the display device  124  attached thereto. As previously noted, the display device  124  can be a LED or LCD display. As depicted in  FIG.  2 B , the display device  124  can be a multi-character display. Alternatively, the display device  124  can be a multi-color display, such as provided by a color LCD or a plurality of different color LEDs (e.g., a red LED, yellow LED and green LED). The display device  124  can also be a multi-symbol display. Although not shown in  FIG.  1   , the UV monitoring glasses  100  can further include an opening or transparent portion at the temple  108  proximate to the display device  124  so that an output from the display device  124  can be visible to a user of the UV monitoring glasses  100 . 
       FIG.  3    is a block diagram of a UV monitoring system  300  according to one embodiment of the invention. The UV monitoring system  300  can be embedded within (i.e., internal to) the housing (i.e., frame) of a pair of glasses. Glasses refer to eyewear. 
     The UV monitoring system  300  includes electrical circuitry  302 . The electrical circuitry  302  can be one or more electrical components, such as integrated circuits, analog components, and/or digital components. One or more solar cells  304  provide power to the electrical circuitry  302 . In other words, when light impinges upon the one or more solar cells  304 , power is produced and supplied to the electrical circuitry  302 . The electrical circuitry  302  receives a UV level indication from a UV detector  306 . In one embodiment, the UV detector  306  includes a photodetector  305  and an optical filter  308 . The optical filter  308  can be integral with or positioned proximate to the photodetector  305  so that the optical filter  308  passes radiation associated with the ultraviolet wavelength range, and such radiation is supplied to the photodetector  305 . As a result, the UV level indication produced by the UV detector  306  is an indication of the UV radiation impinging upon glasses or the user thereof. The electrical circuitry  302  receives the UV level indication from the UV detector  306  and determines whether an output should be signaled by an output device  310 . The output device  310  can take a variety of different forms. For example, the output device  310  can be a display device, such as a LED or LCD display. A display device can produce a visual output. The output device  310  can also be a speaker or a vibration device. The speaker can produce an audio output. For example, the audio output can be a buzzing sound, a beep or a synthesized voice message. 
       FIG.  4 A  is a block diagram of a UV monitoring system  400  according to another embodiment of the invention. The UV monitoring system  400  includes the electrical circuitry  302 , the one or more solar cells  304 , the UV detector  306 , and the output device  310  shown in  FIG.  3   . In addition, the UV monitoring system  400  further includes or makes use of one or more auxiliary sensors  402 . The one or more auxiliary sensors  402  can provide additional sensor information to the electrical circuitry  302 . This additional sensor information can affect the output being provided at the output device  310 . For example, the additional sensor information could be used to provide additional output data or could be used to modify the output data associated with the UV level indication provided by the UV detector  306 . 
       FIG.  4 B  is a block diagram of a UV monitoring system  450  according to still another embodiment of the invention. The UV monitoring system  450  is generally similar to the UV monitoring system  400  shown in  FIG.  4   , but further includes or makes use of a “being worn” detector  452 . The UV monitoring system  450  can be embedded within (i.e., internal to) the housing (i.e., frame) of a pair of glasses. The “being worn” detector  452  would indicate whether the glasses are being worn by its user. For example, the “being worn” detector  452  can be performed using a thermal sensor, a motion detector, a stress sensor or a switch. Although the “being worn” detector  452  is shown separate from the auxiliary sensors  402 , it should be understood that the “being worn” detector  452  can be considered one type of auxiliary sensor. 
       FIG.  4 C  is a block diagram of a UV monitoring system  460  according to yet another embodiment of the invention. The UV monitoring system  460  is generally similar to the UV monitoring system  400  shown in  FIG.  4 A , but further includes a photodetector  462 . Also, in this embodiment, the optical filter  308 ′ blocks UV light and passes other light through to the photodetector  305 ′. As an example, the optical filter  308 ′ can be a thin sheet or coating of polycarbonate. In this embodiment, the photodetector  305 ′ provides an indication of non-UV light, and the photodetector  462  provides an indication of total light. The electrical circuitry  302 ′ receives the indication of non-UV light and the indication of total light. By subtracting the indication of non-UV light from the indication of total light, the electrical circuitry  302 ′ determines an indication of UV light. In one embodiment, the photodetectors  305 ′ and  462  can be Silicon (Si) photodetectors. The electrical circuitry  302 ′ determines whether an output should be signaled by an output device  310  based on the UV level indication. As previously noted, the output device  310  can take a variety of different forms. 
       FIG.  4 D  is a block diagram of a UV monitoring system  470  according to still yet another embodiment of the invention. The UV monitoring system  470  includes the electrical circuitry  302 , the one or more solar cells  304 , the UV detector  306  and the output device  310  shown in  FIG.  3   . In this embodiment, the UV detector  306  measures the UV level indication directly, without the need for an additional optical filter. For example, the UV detector  306  can be a Gallium Nitride (GaN) photodetector since such has a sensitivity to UV radiation. As another example, the UV detector  306  can be a Silicon Carbide (SiC) photodetector since such also has a sensitivity to UV radiation. Silicon Carbide (SiC) detectors may also be suitable for use to detect other types of radiation besides UV. The electrical circuitry  302  receives the UV level indication from the UV detector  306  and determines whether an output should be signaled by the output device  310 . As noted above, the output device  310  can take a variety of different forms. 
     The one or more auxiliary sensors  402  utilized in the UV monitoring system  400  shown in  FIGS.  4 A- 4 D  can vary depending upon application.  FIG.  5    is a chart  500  that depicts examples of auxiliary sensors that can be utilized as the one or more auxiliary sensors  402  shown in  FIGS.  4 A and  4 D . 
     The chart  500  indicates that one type of auxiliary sensor is a “being worn” sensor. The “being worn” sensor would indicate whether the glasses are being worn by its user. The “being worn” sensor can be performed using, for example, a thermal sensor, a motion detector, a stress sensor or a switch. 
     In one embodiment, a motion detector is used as a “being worn” sensor. A threshold can be set, such that if the amount of motion detected exceeds the threshold, the eyewear is assumed to be worn. The motion detector can, for example, be achieved by a mechanical means or an accelerometer. 
     In another embodiment, the “being worn” sensor includes one or more thermal sensors. In the case where two sensors are used, one sensor can be at approximately the middle of a temple, such as in a region that touches the head of the user wearing the glasses, and the other sensor can be positioned at the end of the same temple close to the hinge. If the temperature differential between the two sensors is beyond a certain preset value, the eyewear would be assumed to be worn. 
     In yet another embodiment, the “being worn” sensor includes a stress sensor at the hinge of the temple. The assumption is that when the eyewear is worn, the hinge is typically slightly stretched because typically the width of the head of the user is slightly wider than the width between the temples when the two temples are in the extended positions. If the value of the stress sensor is beyond a certain preset value, the glasses would be assumed to be worn. 
     In still yet another embodiment, the “being worn” sensor can be implemented as a switch. For example, the switch can utilize optical, magnetic or mechanical means. In one embodiment, the switch can be positioned at the temple of the eyewear, such as a forward end of the temple proximate to a corresponding lens holder. Different embodiments of such sensors is also described in U.S. Provisional Patent Application No. 60/583,169, filed Jun. 26, 2004, entitled “ELECTRICAL COMPONENTS FOR USE WITH EYEWEAR, AND METHODS THEREFOR,” which has been incorporated herein by reference, see, e.g., section entitled “EYEGLASSES WITH USER INPUT CAPABILITY.” 
     Another type of auxiliary sensor is an environmental sensor. The environmental sensor can sense environmental conditions, such as one or more of temperature (e.g., ambient temperature), pressure, humidity and toxins (e.g., chemicals, radiation, etc.). 
     Still another type of auxiliary sensor is a physical sensor. The physical sensor can sense physical conditions of the user of the glasses. Examples of physical sensors include sensing one or more of distance traveled, location, speed, calories consumed, temperature, alertness, and vital signs (e.g., heart rate, blood pressure, etc.) associated with the user of the glasses. The distance traveled could represent the horizontal distance traveled or the vertical distance (i.e. elevation) traveled. As one example, a pedometer can provide an estimate of distance traveled The speed can be acquired or determined, such as the rate of movement along the horizontal distance traveled and/or the vertical distance. As another example, calories consumed can be determined (e.g., estimated) based on various physical and/or environmental conditions that can be measured or determined. Still other physical sensors can sense emotions of the user. For example, the physical sensor could sense whether the user is calm, excited, happy, sad, angry, etc. The physical sensor can also more generally sense user activity level. As an example, the user activity level can be used to provide a lifestyle indication. For example, a lifestyle indication might show that the user was active today or, alternatively, lazy today. Such a lifestyle indication can be displayed as a text or graphic symbol to let the user or others aware of the activity level. 
     In one embodiment, one particular type of physical sensor is a heart-beat sensor. The heart-beat sensor measures the heart beat of the wearer of the eyewear. One implementation for the heart-beat sensor utilizes an infrared emitter and an infrared detector as a component. The infrared emitter can be a LED and the infrared detector can be a photodiode with an infrared filter. The component can be located at a temple of the eyewear, with both the emitter and the detector both facing the user when the eyewear is worn. In operation, the infrared emitter shines infrared radiation towards the user, and the detector captures the infrared signals reflected back by the skin of the user. The magnitude of the reflected signals depends on the amount of blood flowing below the skin, which, in turn, depends on the heart beat. The rate of emission by the emitter and reception by the detector can be in a frequency range much higher than the heart beat, such as three thousands cycles per second. And the signals from the detector can be low-pass filtered before they are measured to identify the heart beat of the user. For example, the low-pass filter can be centered at 1 Hz. 
     In should be understood that the sensors might rely on more than one measured criteria. The one or more measured criteria might be used to determine the sensor output. The determination of the sensor output can involve estimation or prediction. 
     The auxiliary sensors can be provided in a redundant or fault-tolerant manner. For example, sensors can be provided in pairs. When one sensor of a pair malfunctions, the other one can replace it. In another embodiment, any of the auxiliary sensor information can be processed in a differential manner to examine changes to the auxiliary sensor information. The auxiliary sensors can by powered by a battery, solar energy, or kinetic energy. For reduced power consumption, the auxiliary sensors can remain in a low-power state unless data is being acquired by the auxiliary sensors. In yet another embodiment, two or more of the auxiliary sensors can communicate with one another (wired or wirelessly) to exchange data or control information. 
     In general, the auxiliary sensors can be fully or partially embedded in the eyewear or a base tethered to the eyewear. Alternatively, one or more of the auxiliary sensors can be separate from the eyewear, or any base tethered thereto, and wirelessly communicate with the eyewear or base. 
       FIG.  6    is a block diagram of a UV monitoring system  600  according to one embodiment of the invention. The UV monitoring system  600  is generally similar to the UV monitoring systems illustrated in  FIGS.  3 - 4 D . However, in the UV monitoring system  600 , a battery  602  provides power to the electrical circuitry  302 . In other words, in this embodiment, the one or more solar cells  304  are optional. The UV monitoring system  600  can operate without the need for any light to impinge upon the one or more solar cells  304 . If the UV monitoring system  600  does include the one or more solar cells  304 , the power produced by the one or more solar cells  304  can be coupled to the battery  602  so as to recharge the battery. The battery  602  also allows the electrical circuitry  302  to maintain data even while no light is present (e.g., if a volatile memory is used to store data). The ability to maintain data (such as in a memory device) can be advantageous. For example, the UV monitoring system  600  may desire to output information over longer durations of time, or may desire to process data in a differential manner. The UV monitoring system  600  can also further include one or more auxiliary sensors. 
       FIG.  7 A  is a schematic diagram of a UV monitoring circuit  700  according to one embodiment of the invention. The UV monitoring circuit  700  includes a phototransistor  702 . Although the phototransistor  702  may itself serve as a UV detector, in some implementations, an optical filter (not shown) would limit the radiation that impinges on the phototransistor  702 , in which case the phototransistor  702  together with the optical filter serves as the UV detector. A collector terminal of the phototransistor  702  is coupled to a power source Vcc. The power source Vcc can be provided by a battery or solar cell(s). An emitter terminal of the phototransistor  702  is coupled to a first end of a resistor  704 , a first end of the capacitor  706  and a gate terminal of a transistor  708 . As an example, the transistor  708  can be an n-channel metal-oxide-semiconductor, enhancement-mode, field-effect transistor (MOSFET). A second end of the resistor  704 , a second end of the capacitor  706  and a source terminal of the transistor  708  are coupled to ground. An output device  710  couples between the power source Vcc and a drain terminal of the transistor  708 . As sufficient radiation, such as UV radiation, impinges on the phototransistor  702 , the phototransistor  702  conducts so that the emitter terminal of the phototransistor  702  outputs the voltage V 1  by coupling to the power source Vcc through the phototransistor  702 . The voltage V 1  is dependent on the amount of UV radiation that impinges on the phototransistor  702 . The capacitor  706  then charges up in accordance with a time constant determined by the capacitance of the capacitor  706  and the resistance of the resistor  704 . When the voltage V 1  exceeds a turn-on voltage for the transistor  708 , the transistor  708  conducts and the output device  710  is activated. For example, the output device  710  can indicate that the UV monitoring circuit has detected exposure to a large amount of UV radiation. The amount of UV radiation exposure being detected can vary depending on the capacitance of the capacitor  706  and the resistance of the resistor  704 . 
       FIG.  7 B  is a schematic diagram of a UV monitoring circuit  750  according to another embodiment of the invention. The UV monitoring circuit  750  includes a phototransistor  752 . Although the phototransistor  752  may itself serve as a UV detector, in some implementations, an optical filter (not shown) would limit the radiation that impinges on the phototransistor  752  in which case the phototransistor  752  together with the optical filter serves as the UV detector. A collector terminal of the phototransistor  752  is coupled to a power source Vcc. The power source Vcc can be a battery or solar cell(s). An emitter terminal of the phototransistor  752  is coupled to a first end of a resistor  754  as well as to an input to an analog-to-digital (A/D) converter  756 . The second end of the resistor  754  couples to ground. The A/D converter  756  converts the voltage level at the emitter terminal of the phototransistor  752  to a digital voltage value having n bits. The digital voltage value represents the UV radiation impinging on the phototransistor  752 . The digital voltage value is supplied to a controller  758 . The controller  758  can, for example, be a microcontroller. In one embodiment, the microcontroller is a microprocessor. An output device  760  couples between the power source Vcc and ground. The output device  760  also couples to an output terminal of the controller  758 . As sufficient radiation, such as UV radiation, impinges on the phototransistor  752 , the phototransistor  752  conducts so that a voltage is supplied to the A/D converter  756  which produces the corresponding digital voltage value. The digital voltage value is dependent on the amount of UV radiation that impinges on the phototransistor  752 . The controller  758  can then determine whether to activate the output device  760 . For example, controller  758  can activate the output device  760  to indicate that the UV monitoring circuit  750  has detected (i) current exposure to a substantial (e.g., large) amount of UV radiation (e.g., amount of UV radiation greater than a threshold amount), and/or (ii) exposure to a substantial (e.g., large) amount of UV radiation accumulated over a time period (e.g., accumulated amount of UV radiation greater than a threshold amount). Although not shown, the controller  758  can also receive sensor information from one or more other auxiliary sensors and signal other types of outputs via the output device  760 . 
       FIG.  7 C  is a schematic diagram of a UV monitoring circuit  770  according to yet another embodiment of the invention. The UV monitoring circuit  770  includes a phototransistor  772 . Although the phototransistor  772  may itself serve as a UV detector, in some implementations, an optical filter (not shown) would limit the radiation that impinges on the phototransistor  772  in which case the phototransistor  772  together with the optical filter serves as the UV detector. A collector terminal of the phototransistor  772  is coupled to a power source Vcc. An emitter terminal of the phototransistor  772  is coupled to a first end of a resistor  774 , a first end of a capacitor  776  and a gate terminal of a transistor  778 . An output device  780  couples between the power source Vcc and a drain terminal of the transistor  778 . A second end of the resistor  774 , a second end of a capacitor  776  and a source terminal of the transistor  778  are coupled to a drain terminal of a transistor  784 . As an example, the transistors  778  and  784  can be n-channel metal-oxide-semiconductor, enhancement-mode, field-effect transistors (MOSFETs). As one example, MOSFETs can be 2N7008 MOSFETs. The source terminal of the transistor  784  is coupled to ground. The gate terminal of the transistor  784  is coupled to a first end of a resistor  786  and a first end of a capacitor  788 . A second end of the resistor  786  and the second end of the capacitor  788  are coupled to ground. The gate terminal of the transistor  784  is also coupled to the power source Vcc through a being-worn switch  782 . A battery  790  can supply power to the UV monitoring circuit  770 . As one example, the battery  790  can be a three (3) Volt lithium battery. The size and configuration of the battery  790  can also vary. In one example, the battery  790  can be a coin battery. In another example, the battery  790  can be a triple-A (AAA) battery. As sufficient radiation, such as UV radiation, impinges on the phototransistor  772 , the phototransistor  772  conducts so that the emitter terminal of the phototransistor  772  outputs the voltage V 1  by coupling to the power source Vcc through the phototransistor  772 . The capacitor  776  then charges up in accordance with a time constant determined by the capacitance of the capacitor  776  and the resistance of the resistor  774 . When the voltage V 1  exceeds a turn-on voltage for the transistor  778 , the transistor  778  conducts. However, in this embodiment, the transistor  784  also must conduct in order for the output device  770  to be activated. The transistor  784  conducts when the “being worn” switch  782  is closed. The “being worn” switch  782  indicates whether the eyewear (including the UV monitoring circuit  770 ) is being worn by its user. The sensitivity of the “being worn” switch  782  can be controlled by the capacitance of the capacitor  788  and the resistance of the resistor  786 . For example, the output device  780  can indicate that the UV monitoring circuit  770  has detected exposure to a large amount of UV radiation while the eyewear is being worn. The amount of UV radiation exposure being detected can vary depending on the capacitance of the capacitor  776  and the resistance of the resistor  774 . 
     The UV monitoring circuits according to the invention can also include switches, such as a “being-worn” switch, skin type, reset switch and/or an on/off switch. A “being-worn” switch was, for example, discussed above with reference to  FIG.  7 C . The on/off switch can also provide a reset capability. A reset switch and an/on switch are further discussed below with reference to  FIG.  7 D . 
       FIG.  7 D  is a schematic diagram of a UV monitoring circuit  770 ′ according to still yet another embodiment of the invention. The UV monitoring circuit  770 ′ is generally similar to the UV monitoring circuit  770  of  FIG.  7 C , except that a reset switch  792 , an on switch  794  and an off switch  796  are provided. Additionally, the resistor  786  shown in  FIG.  7 C  is removed from the UV monitoring circuit  770 ′. The reset switch  792  can be a push button, such that when pressed, causes any charge on the capacitor  776  to be discharged. As a result, assuming the transistor  778  is conducting (i.e., on) when the reset switch is pushed, the transistor  778  stops conducting (i.e., off) because the voltage V 1  is effectively zeroed and thus does not exceed the turn-on voltage for the transistor  778 . Consequently, the output device  780  stops providing any output (e.g., display device cleared or off, audio stopped, etc.). Once the reset switch  792  is released, the capacitor  776  can again begin to accumulate charge representing UV radiation. The on switch  794  and the off switch  796  can also be implemented as push button switches. When the on switch  794  is pressed, the capacitor  788  is charged so that the transistor  784  conducts (i.e., turns-on) and then remains on until the off switch  796  is pressed. In this embodiment, the on switch  794  and the off switch  796  should not both be pressed at the same time. Although the reset switch  792 , the on switch  794  and the off switch  796  are implemented as push button switches in  FIG.  7 D , other types of switches can be used. 
       FIG.  8    is a flow diagram of a UV monitoring process  800  according to one embodiment of the invention. The UV monitoring process  800  is, for example, performed by a UV monitoring system embedded within and/or tethered to a pair of glasses. The UV monitoring system can, for example, represent any of the UV monitoring systems  300 ,  400 ,  450 ,  460 ,  470 ,  600 ,  700 ,  750 ,  770  or  770 ′ discussed above with reference to  FIGS.  3 ,  4 A- 4 D,  6  and  7 A- 7 D . 
     The UV monitoring process  800  begins with a decision  802  that determines whether the glasses are being worn. As noted above, the determination of whether the glasses are being worn can be done in a variety of ways. In any case, when the decision  802  determines that the glasses are not being worn, then the UV monitoring process  800  waits until the glasses are being worn. In other words, when the glasses are not being worn, the UV monitoring process  800  can stop, block (pause or wait) or deactivate until it is determined that the glasses are being worn. 
     On the other hand, when the decision  802  determines that the glasses are being worn, a UV radiation level is acquired  804 . For example, the UV radiation level can be acquired  804  from electronic circuitry which can include a UV detector. Next, UV information is determined  806  based on the UV radiation level (radiation data). For example, the UV information can pertain to normalized or calibrated radiation data, accumulated radiation data, or processed radiation data. Hence, although the UV radiation level (radiation data) could be output to the user, by outputting the UV information to the user of the glasses, more useful information (e.g., easier to comprehend) can be presented to the user. Other examples of UV information are referenced elsewhere, such as the UV radiation information discussed below in  FIG.  9   . 
     Next, the UV information can be output  808  to the output device. The UV information need not always be output  808  to the output device. For example, the UV information could be output  808  to the output device depending upon whether it signals a particular condition to the user. As another example, the UV information could be output to the output device on request by the user. As still another example, the UV information could be output to the output device based on a sensed condition or event. Next, a decision  810  can determine whether the UV monitoring process  800  should continue. When the decision  810  determines that the UV monitoring process  800  should not continue, then the UV monitoring process  800  waits until it is time to be continued. This allows the UV monitoring process  800  to be performed periodically or as needed, which can lead to reduced power consumption and/or more meaningful output information to the user. While the UV monitoring process  800  is waiting, some or all of the UV monitoring system can be in a reduced power consumption state. Nevertheless, when the decision  810  determines that the UV monitoring process  800  should continue, the UV monitoring process  800  returns to repeat the decision  802  and subsequent operations. 
       FIG.  9    is a flow diagram of a UV monitoring process  900  according to another embodiment of the invention. The UV monitoring process  900  is, for example, performed by a UV monitoring system embedded within and/or tethered to a pair of glasses. The UV monitoring system can, for example, represent any of the UV monitoring systems  300 ,  400 ,  450 ,  460 ,  470 ,  600 ,  700 ,  750 ,  770  or  770 ′ discussed above with reference to  FIGS.  3 ,  4 A- 4 D,  6  and  7 A- 7 D . However, the UV monitoring process  900  is particularly suitable for UV monitoring systems having “being worn” detection capability, such as the UV monitoring systems  450  and  770 . 
     The UV monitoring process  900  begins with a decision  902  that determines whether adequate solar energy is present. In this embodiment, solar cells provide adequate solar energy for the UV monitoring process  900  to be performed. In other words, the UV monitoring system (and thus the glasses) operate in the presence of light. When the decision  902  determines that adequate solar energy (e.g., sunlight or artificial light) is not present, then the UV monitoring process  900  awaits adequate solar energy. In one implementation, the UV monitoring system performing the UV monitoring process  900  can automatically turn-off or deactivate when inadequate solar energy is present. Such operation facilitates passive UV monitoring with minimal user participation. 
     On the other hand, when the decision  902  determines that adequate solar energy is present, a decision  904  determines whether the glasses are being worn. When the decision  904  determines that the glasses are not being worn, then the UV monitoring process  900  returns to repeat the decision  902  and subsequent operations. In effect, the UV monitoring process  900  is not performed when the decision  904  determines that the glasses are not being worn by the user. As noted above, the determination of whether the glasses are being worn can be done in a variety of ways. 
     Optionally, a delay can be inserted when the decision  904  determines that the glasses are not being worn so as to save power consumption. Such a delay would allow the UV monitoring process  900  to stop, halt, inactivate or otherwise wait for the period of the delay prior to returning to the decision  902  and subsequent operations. While the UV monitoring process  900  is stopped, halted, inactivated or otherwise waiting, some or all of the UV monitoring system can be in a reduced power consumption state. 
     Alternatively, when the decision  904  determines that the glasses are being worn, a decision  906  can determine whether an interval timer has expired. The interval timer can determine how frequently the UV radiation level is checked and/or how frequently radiation information is output to a display. The interval timer can also thus lead to reduced power consumption (i.e., low-power mode for the electronic circuitry). When the decision  906  determines that the interval timer has not expired, the UV monitoring process  900  waits for the interval timer to expire. During this period of waiting, the UV monitoring process  900  can place some or all of the UV monitoring system in a low-power mode. Alternatively, during this period of waiting, the UV monitoring process  900  can perform processing of other auxiliary sensors that can produce other sensor data which can be processed in conjunction with UV radiation levels. 
     Once the decision  906  determines that the interval timer has expired, a UV radiation level is acquired  908 . Then, UV radiation information is output  910  to the user of the glasses based on the UV radiation level. For example, the UV radiation information can pertain to an instantaneous radiation level, an accumulated radiation level, or some reference radiation indication. An example of a reference radiation indication can be a numerical value, text or a graphic indication. One example of a numerical value implementation is a value representing a percentage of recommended daily dosage. Another example of a numerical value implementation is a value representing UV intensity. One example of a text implementation would be a word (e.g., “ok”, “Burnt”, etc.). One example of a graphic implementation would be a bar-type graph. Another example of a graphic implementation would be a graphic symbol (e.g., a lobster symbol, a fire flames symbol, a picture of a sun, or a smiley face). 
     Next, the interval timer can be reset  912  and the UV monitoring process  900  can thereafter return to repeat the decision  902  and subsequent operations. As a result, the UV monitoring provided by the UV monitoring process  900  can be continuously performed so long as adequate solar energy is present and the glasses are being worn. 
       FIG.  10    is a flow diagram of a UV monitoring process  1000  according to yet another embodiment of the invention. The UV monitoring process  1000  is, for example, performed by a UV monitoring system embedded within and/or tethered to a pair of glasses. The UV monitoring system can, for example, represent any of the UV monitoring systems  300 ,  400 ,  450 ,  460 ,  470 ,  600 ,  700 ,  750 ,  770  or  770 ′ discussed above with reference to  FIGS.  3 ,  4 A- 4 D,  6  and  7 A- 7 D . 
     The UV monitoring process  1000  begins with a decision  1002  that determines whether adequate solar energy (e.g., sunlight or artificial light) is available. When the decision  1002  determines that adequate solar energy is not available, then the UV monitoring process  1000  is deactivated, blocked or effectively not invoked. In this embodiment, solar cells provide adequate solar energy for the UV monitoring process  1000  to be performed. In other words, the glasses operate in the presence of sufficient light. When the decision  1002  determines that adequate solar energy is not present, then the UV monitoring process  1000  awaits adequate solar energy. 
     Once the decision  1002  determines that adequate solar energy is available, then the UV monitoring process  1000  proceeds. Here, the UV monitoring process  1000  can optionally determine whether the glasses are being worn. In any case, as shown in  FIG.  10   , when the decision  1002  determines that adequate solar energy is available, a UV radiation level is acquired  1004 . For example, the UV radiation level can be acquired by a UV detector. 
     Next, the UV radiation level is accumulated  1006  during a time period. Here, the UV radiation levels acquired over a predetermined period of time are accumulated  1006  so that the radiation information is based on an accumulation of radiation that has been acquired over the predetermined period of time. For example, the predetermined period of time can be one hour, four hours, eight hours, twelve hours, twenty-four hours, two days, four days, one week, one month or one year. 
     Thereafter, a decision  1008  determines whether a UV radiation warning is needed. Here, the accumulated UV radiation level can be compared with a threshold to determine whether the accumulated UV radiation is excessive. In one implementation, the threshold can vary with, or be personalized to, different users, such as based on skin type, age, or skin condition. A user of the glasses can input data (e.g., skin type) by way of at least one switch or button. In another implementation, a plurality of threshold levels can be used, e.g., to provide a progression of UV radiation levels (and notifications). Alternatively, the glasses can use predetermined settings and offer several versions (e.g., different glasses for different skin types). 
     When the decision  1008  determines that the UV radiation warning is not needed, then the UV monitoring process  1000  returns to repeat the decision  1002  and subsequent operations so that the UV radiation level can continuously or periodically be monitored. In one embodiment, the UV monitoring process  1000  can reset the accumulated UV radiation after the period of time has been exceeded. In another embodiment, the accumulated UV radiation can be reset after no significant UV radiation is present for a period of time (e.g., 6-12 hours), after no significant solar energy is present for a period of time (e.g., 6-12 hours), or after not being worn for a period of time (e.g., 6-12 hours), whereby each evening, for example, the reset can automatically occur. In another embodiment, the UV monitoring system, and thus the UV monitoring process  1000 , can be automatically turned off (which also resets) after the period of time has been exceeded or after no significant UV radiation is present for a period of time. 
     On the other hand, when the decision  1008  determines that a UV radiation warning is needed, then a UV radiation warning is output  1010  to the user. The warning can be varied or personalized to the user, and/or can vary depending on the user, user preference, UV radiation level, or auxiliary sensor data. In one implementation, the warning can pertain to a recommendation (e.g., SPF recommendation, get out of sun, high exposure warning, etc.). The radiation warning can be output  1010  via the output device. For example, as noted above, the output device can be a display, a speaker or a vibration device. Hence, the warning can be output to the user by displaying text or graphics, audio sounds, or physical actions. Following the output  1010  of the UV radiation warning, the UV monitoring process  1000  can return to repeat the decision  1002  and subsequent operations so that UV monitoring can continue. 
     Although the circuitry in  FIGS.  7 A- 7 D  and the processing in  FIGS.  8 - 10    have been described in the context of monitoring UV radiation, it should be understood that such circuitry and processing are also applicable to monitoring other types of radiation. 
       FIG.  11    is a flow diagram of a monitoring process  1100  according to still yet another embodiment of the invention. The monitoring process  1100  is, for example, performed by a monitoring system embedded within and/or tethered to a pair of glasses. The monitoring system can, for example, represent any of the UV monitoring systems  300 ,  400 ,  450 ,  460 ,  470 ,  600 ,  700 ,  750 ,  770  or  770 ′ discussed above with reference to  FIGS.  3 ,  4 A- 4 D,  6  and  7 A- 7 D . 
     The monitoring process  1100  begins with a decision  1002  that determines whether adequate solar energy (e.g., light) is available. In one implementation, the monitoring system performing the monitoring process  1100  includes at least one solar cell or at least one phototransistor, and the solar cell or phototransistor can be used to determine whether there is adequate solar energy available. Hence, when the decision  1102  determines that adequate solar energy is not available, then the monitoring process  1100  is deactivated, blocked or effectively not invoked. In this embodiment, solar cells can provide adequate solar energy for the monitoring process  1000  to be performed. In another embodiment, a phototransistor can detect whether adequate solar energy is available. In other words, the glasses operate in the presence of sufficient light. When the decision  1102  determines that adequate solar energy is not present, then the monitoring process  1100  awaits adequate solar energy. In this condition, the monitoring system can be in a low power condition (e.g., essentially disabled). 
     Once the decision  1102  determines that adequate solar energy is available, then the monitoring process  1100  proceeds. Here, the monitoring process  1100  can optionally determine whether the glasses are being worn. In any case, as shown in  FIG.  11   , when the decision  1102  determines that adequate solar energy is available, a decision  1104  determines whether the glasses are being worn by a user. When the decision  1104  determines that the glasses are not being worn or when the decision  1102  determines that adequate solar energy is not present, then a radiation level previously acquired through accumulation (described below) can be slowly dispersed  1106 . In one embodiment, the rate of dispersal is substantially slower that the rate of accumulation of the UV radiation level. For example, in a case where the radiation being monitored is UV radiation, the UV radiation level might accumulate to cause a UV radiation warning after 1-2 hours of extensive UV or sunlight exposure, but might take 6-12 hours to disperse the previously accumulated radiation level after the UV radiation is removed. Hence, the accumulation of radiation can gracefully tolerate interruption of radiation, such as when going indoors (e.g., within a building) for a period of time (e.g., 15 minutes, 1 hour, 4 hours, etc.) when UV radiation is being monitored. Following the block  1106 , the monitoring process  1100  returns to repeat the decision  1102  and subsequent blocks. 
     On the other hand, when the decision  1104  determines that the glasses are being worn, a radiation level is acquired  1108 . For example, the radiation level can be acquired by a detector (e.g., UV detector). Next, the radiation level is accumulated  1110 . Here, the radiation levels acquired can be accumulated so that radiation information can be based on an accumulation of radiation that has been acquired while the glasses are being worn. 
     Thereafter, a decision  1112  determines whether a radiation warning is needed. Here, the accumulated radiation level can be compared with a threshold to determine whether the accumulated radiation is excessive. In one implementation, the threshold can vary with, or be personalized to, different users, such as based on skin type, age or skin condition. In another implementation, a plurality of threshold levels can be used, e.g., to provide a progression of radiation levels (and notifications). A user of the glasses can input data (e.g., skin type, preferences) by way of at least one switch or button. Alternatively, the glasses can use predetermined settings and offer several versions (e.g., different glasses for different skin types). 
     When the decision  1112  determines that the radiation warning is not needed, then the monitoring process  1100  deactivates  1114  the radiation warning. Alternatively, when the decision  1112  determines that the radiation warning is needed, then the monitoring process  1100  activates  1116  the radiation warning. The warning can be varied or personalized to the user, and/or can vary depending on the user, user preference, radiation level, or auxiliary sensor data. The radiation warning can be produced at an output device. For example, as noted above, the output device can be a display, a speaker or a vibration device. In one implementation, the warning is a graphical symbol or text that signals the user of the glasses that they have received a significant amount of radiation. Following the deactivation  1114  and the activation  1116 , the monitoring process  1100  can return to repeat the decision  1102  and subsequent operations so that monitoring can continue. 
     The radiation warning can remain active anywhere from a brief period to continuously depending on the type of warning being provided, user preference or manufacturer setting. For example, an audio alert might sound for a few seconds, while a displayed alert might remain on for a longer duration. The radiation warning can be output differently depending on the power situation of the monitoring system. If the monitoring system is being solar powered, then the radiation warning can remain active until deactivated. However, when the monitoring system is being battery powered, the radiation warning might be active for only a brief period. 
       FIG.  12    is a block diagram of electronic circuitry  1200  according to one embodiment of the invention. The electronic circuitry  1200  can, for example, be used for at least a part of the electronic circuitry  302  shown in  FIGS.  3 ,  4 A,  4 B,  4 D and  6   . The electronic circuitry  1200  includes a radiation detector  1202  that outputs a radiation level signal dependent on an amount of radiation impinging on the radiation detector  1202 . For example, in the case where radiation from sunlight is being monitored, the radiation detector  1202  can principally detect ultraviolet or infrared radiation. In another example, in the case where radiation from x-ray machines or nuclear materials is being monitored, the radiation detector can principally detect gamma radiation. A radiation accumulator  1204  receives the radiation signal level and accumulates the radiation signal level to produce an accumulated radiation level. A level comparator  1206  can then compare the accumulated radiation level to a threshold level (TH). The threshold level can be fixed, selected or determined. When the accumulated radiation level exceeds the threshold level, then an output driver  1208  operates to output one or more signals to cause an output device to produce an output. The output can be visual, audio, and/or physical. The threshold can be varied or personalized to the user, and/or can vary depending on the user. The threshold can also depend on or vary in view of one or more of user preferences, position (e.g., closer equator), intensity level of radiation, user characteristics (e.g., skin color or type), or auxiliary sensor data, etc. The level comparator  1206  can also use one or more threshold levels. 
     In one embodiment, the threshold used by the level comparator  1206  can correspond to a recommended daily dosage of such radiation. For example, if the radiation detector  1202  is primarily detecting UV radiation, the recommended daily dosage would pertain to UV radiation. 
       FIG.  13 A  is a schematic diagram of an electronic circuit  1300  for a radiation detection system according to one embodiment of the invention. The electronic circuit  1300  is, for example, suitable for use as the electronic circuitry  1200  shown in  FIG.  12   . 
     The electronic circuit  1300  includes a phototransistor  1302  and a resistor (R 1 )  1304  coupled in series between a supply voltage (Vs) and ground. In this embodiment, the phototransistor  1302  implements a radiation detector. As radiation (of an appropriate frequency range) strikes the phototransistor  1302 , a voltage V 1  appears at a first node connecting the phototransistor  1302  to the resistor (R 1 )  1304 . The voltage V 1  induces a current  11  that passes through a diode  1305  and a resistor (R 2 )  1306 . A voltage V 2  at a second node then begins to rise from ground level to the level of V 1  by the charging of a capacitor (C 1 )  1308  at a rate dependent on the amount of the current  11  and the capacitance of the capacitor (C 1 )  1308  and the resistances of the resistors (R 2  and R 3 )  1306  and  1310 , respectively. A Schmitt trigger inverter  1312  couples to the second node and receives the voltage V 2  at its input. When the voltage V 2  exceeds the turn-on voltage for the inverter  1312 , the output of the inverter  1312  goes low and couples to a third node via a diode  1314 . At this point, the low voltage (V 3 ) at the third node couples to an input of a Schmitt trigger inverter  1316 , which outputs a high voltage (V 4 ) at a fourth node which charges a resistor (R 4 )  1318  and capacitor (C 2 )  1320 . The resistor (R 4 )  1318  couples between the third and fourth nodes. The capacitor (C 2 ) couples between the third node and ground. Once the voltage V 3  has risen sufficiently, the inverter  1316  switches to output a low voltage (V 4 ), thereby discharging the capacitor (C 2 )  1320 . Hence, the inverter  1316 , the resister (R 4 )  1318  and the capacitor (C 2 )  1320  form an oscillator. The outputs for the electronic circuit  1300  are complementary, a positive output from the fourth node and a negative output from an inverter  1322  coupled to the fourth node. These complementary outputs are applicable for driving a LCD type display device. 
     Although not shown in  FIG.  13 A , the electronic circuit  1300  can optionally further include a reset switch. For example, if provided, the reset switch can be coupled between the second node and ground. While the reset switch is normally open, when closed the reset switch discharges the capacitor (C 1 )  1308 . As an example, the reset switch can be implemented by a push button switch. Although the electronic circuit  1300  can automatically reset after no significant UV radiation is present for a period of time (such as noted above), the reset switch permits a user to manually reset the electronic circuit  1300  so as to clear and restart monitoring (e.g., accumulation) of radiation. 
     The electronic circuit  1300  can facilitate low power operation. In one implementation, the resistor (R 1 )  1304  can be made large. In another implementation, power dissipated by resistor (R 1 ) can be conserved by using a radiation detector, such as a phototransistor, that is responsive to the radiation of interest but with very low sensitivity to the radiation of interest. In the case of a phototransistor, sensitivity can be reduced by covering the phototransistor with a layer of aluminized Mylar. Aluminized Mylar can attenuate light passing through it by a factor of approximately one-thousand ( 1000 ). In still another implementation, the supply voltage (Vs) supplied to the phototransistor  1302  can be periodic, so that power consumed by the resister (R 1 ), which, in this case, need not be a high resistance, is substantially reduced, yet the phototransistor  1302  has an extended dynamic range. The sensitivity of the radiation measurement can also be adjusted by changing the duty-cycle of the periodic supply voltage (Vs). These various implementations for low power operation can be used singly or in combination. 
       FIG.  13 B  is a schematic diagram of a periodic supply voltage circuit  1350  according to one embodiment of the invention. The periodic supply voltage circuit  1350  is, for example, suitable for use to provide a supply voltage (Vs) to the electronic circuit  1300  for a radiation detection system. In this embodiment the supply voltage (Vs) is periodic. In this example, the supply voltage (Vs) uses pulse-width modulation. The periodic supply voltage circuit  1350  includes a Schmitt trigger inverter  1352  that is powered by a power supply (Vcc) when the radiation detection system is operating (i.e., turned-on). At this point, the voltage (V 5 ) at an input node is assumed low and couples to an input of the Schmitt trigger inverter  1352 , which outputs a high voltage (V 6 ) at an output node which charges a capacitor (C 3 )  1360  via resistor (R 5 )  1354  and resistor (R 6 )  1358 . A diode  1356  conducts during charging, but blocks during discharging. The resistor (R 5 )  1354  couples between the input and output nodes. The diode  1356  and the resistor (R 6 )  1358  are coupled in series between the input and output nodes. The capacitor (C 3 )  1360  couples between the input node and ground. Once the voltage (V 5 ) at the input node has risen sufficiently, the inverter  1352  switches to output a low voltage (V 6 ) at the output node, thereby discharging the capacitor (C 3 )  1360  via the resistor (R 5 )  1354 . Hence, the periodic supply voltage circuit  1350  forms an oscillator. The output for the periodic supply voltage circuit  1350  at the output node (V 6 ) can be the supply voltage (Vs) for the radiation detection system. Given the diode  1356 , the supply voltage (Vs) is in the high state for a short time and in the low state for a longer period of time. 
     Although the resistance and capacitance values for the electronic circuit  1300  and the periodic supply voltage circuit  1350  can vary widely with implementation and application, some exemplary values are as follows. For example, for the electronic circuit  1300 , the resistor (R 1 )  1304  can be 22 k ohms, the resistor (R 4 )  1318  can be 330 k ohms, and the capacitor (C 2 )  1320  can be 0.1 microfarads (μf). The resistor (R 2 )  1306  and the resistor (R 3 )  1310  can, for example, be in the range of 1-50 M ohms. The capacitor (C 1 )  1308  can, for example, be in the range of 1-100 μf. For example, for the periodic supply voltage circuit  1350 , the resistor (R 5 )  1354  can be 10 M ohms, the resistor (R 6 )  1358  can be 200 k ohms, and the capacitor (C 3 )  1360  can be 0.01 μf. 
       FIG.  14 A  is a block diagram of a radiation monitoring system  1400  according to one embodiment of the invention. The radiation monitoring system  1400  can, for example, be used for the electronic circuitry  302  shown in  FIGS.  3 ,  4 A,  4 B,  4 D and  6   . The radiation monitoring system  1400  includes a radiation detector  1402  that detects impinging radiation, such as ultraviolet radiation, infrared radiation or light, and outputs a radiation indication to a radiation-to-frequency converter  1404 . The radiation indication can represent an amount of radiation impinging on the radiation detector  1402 . The radiation-to-frequency converter  1404  converts the radiation indication into a frequency signal. The frequency signal is supplied to an output manager  1406 . The output manager  1406  coordinates when an output is to be provided for the radiation monitoring system  1400 . In one embodiment, the output manager  1406  determines that an output indication should be provided based on a count or a division with respect to the frequency signal. For example, the greater the amount of radiation being detected by the radiation detector  1402 , the greater the frequency of the frequency signal. Hence, when greater levels of radiation are detected, the output manager  1406  can more quickly provide an output indication (e.g., signaling substantial radiation exposure) as compared to a situation in which the amount of radiation being detected by the radiation detector  1402  is substantially less. 
     In any case, when the output manager  1406  determines that an output indication is to be provided, the output manager  1406  provides an output signal to an output driver  1408 . The output driver  1408  controls an output device so as to produce an output indication. The output indication can be textual (including numerical) and/or graphical. For example, as a numerical output, the output could indicate a percentage of acceptable radiation for a day that has been already detected. As another example, the output could be a graphical output that pertains a symbol or a graph. In one embodiment, the output provided by the output device is a visual output on a display device. However, in general, the output can be visual and/or audio. For example, examples of audio outputs are beeping sounds, synthesized speech, or prerecorded audio messages. 
     The output manager  1406  receives the frequency signal from the radiation-to-frequency converter  1404  and can determines when an output indication should be provided. In one implementation, the output manager  1406  can include a divider that divides down the frequency signal from the radiation-to-frequency converter  1404  such that the output manager  1406  causes the output driver  1408  to produce an output indication based on an amount of radiation that has effectively been detected. As an example, a predetermined amount of radiation to be effectively detected can be controlled by altering the amount of division provided by the divider. Hence, the amount of division utilized by the output manager  1406  can correspond to a radiation threshold amount, such as a recommended daily dosage of ultraviolet radiation. The amount of division provided by the divider can also depend on or vary in view of one or more of user preferences, position (e.g., proximity to equator), intensity level of radiation, user characteristics (e.g., skin color or type), or auxiliary sensor data, etc. Alternatively, the output manager  1406  can include a counter that counts based on the frequency signal from the radiation-to-frequency converter  1404 , wherein the amount of count utilized by the output manager  1406  can also correspond to a radiation threshold amount. 
     In an alternative embodiment, the radiation-to-frequency converter  1404  can instead be a radiation-to-pulse-width converter. The radiation-to-pulse-width converter can convert the radiation indication into a pulse-width signal. The pulse-width signal is supplied to an output manager  1406 . The output manager  1406  arranges when an output is to be provided for the radiation monitoring system  1400 . In one embodiment, the output manager  1406  determines that an output indication should be provided based on the width of the pulse of the pulse-width signal. 
       FIG.  14 B  is a block diagram of a radiation monitoring system  1420  according to another embodiment of the invention. The radiation monitoring system  1420  is, for example, a detailed embodiment of the radiation monitoring system  1400  illustrated in  FIG.  14 A . 
     The radiation monitoring system  1420  includes a sensor  1422 . The sensor  1422  senses radiation, such as ultraviolet radiation or infrared radiation. The sensor  1422  outputs a radiation indication to a radiation-to-frequency converter  1424 . The radiation-to-frequency converter  1424  outputs a frequency signal ϕ 1  to a divider  1426 . The divider  1426  divides the frequency signal ϕ 1  and outputs a divided frequency signal Q N . The divided frequency signal Q N  is supplied to a latch  1428 . As shown in  FIG.  14 B , in one embodiment, the latch  1428  can be a set-reset type of latch. The output of the latch  1428  is an output signal (OUT). The output signal (OUT) is supplied to a LCD driver  1430 . When the output signal (OUT) is high, the LCD driver  1430  causes an output indication to be provided on a LCD display  1432 . 
     Still further, the radiation monitoring system  1420  includes a power supply  1434  that supplies power to various components under the radiation monitoring system  1420 . The power supply  1434  outputs a positive voltage (V+), a ground signal (GND), and a negative voltage (B−). The signals provided by the power supply  1434  are supplied to various components of the radiation monitoring system  1420  as shown in  FIG.  14 B . In addition, the radiation monitoring system  1420  includes a first switch (S 1 ) and a second switch (S 2 ). The first switch (S 1 ) is a reset switch that is coupled to the divider  1426  and the latch  1428 . When the first switch (S 1 ) is closed a reset operation occurs so that the divider  1426  and the latch  1428  are reset. Hence, any accumulated data in these components is cleared. As a result, radiation monitoring can be cleared and restarted by closing and then opening the first switch (S 1 ). The second switch (S 2 ) is coupled to the power supply  1434  and serves as an on-off switch. When the second switch (S 2 ) is closed (i.e., “switched on”), the power supply  1434  outputs various voltage signals. On the other hand, when the second switch (S 2 ) is open (i.e., “switched off”), the power supply  1434  does not output the voltage levels. 
     As noted above, the radiation monitoring system  1420  is an example of a more detailed embodiment of the radiation monitoring system  1400  illustrated in  FIG.  14 A . As such, the divider  1426  and the latch  1428  together can correspond to the output manager  1406  in one embodiment, and the LCD driver  1430  can corresponds to the output driver  1408  in one embodiment. 
       FIG.  14 C  is a schematic diagram of a radiation-to-frequency converter  1440  and a sensor according to one embodiment of the invention. The radiation-to-frequency converter  1440  represents a detailed embodiment for the radiation-to-frequency converter  1424  illustrated in  FIG.  14 B . As shown in  FIG.  14 C , the sensor includes a phototransistor  1442  that serves as a radiation sensor. In particular, the phototransistor  1442  can be sensitive to a particular wavelengths of radiation, such as ultraviolet radiation or infrared radiation. As radiation impinges on the phototransistor  1442 , a voltage dependent upon the amount of radiation impinging on the phototransistor  1442  is produced at a first node  1444 . The first node  1444  is coupled to ground by a capacitor  1446 . A Schmitt trigger inverter  1448  couples between the first mode  1444  and a second node  1450 . The output of the radiation-to-frequency converter  1440  is provided at the second node  1450  and pertains to the frequency signal ϕ 1 . The phototransistor  1442  is also coupled between the first node  1444  and the second node  1450 . In addition, a series combination of a resistor  1452  and a diode  1454  are also coupled between the first node  1444  and the second node  1450 . The frequency signal ϕ 1  being produced at the second node  1450  has a frequency that is dependent upon the resistance of the resistor  1452 , the capacitance of the capacitor  1446 , the sensitivity of the phototransistor  1442 , and the amount of radiation impinging upon the phototransistor  1442 . If the first node  1444  is low, the second node  1452  is high. In such a situation, radiation impinging upon the phototransistor  1442  causes the first node  1444  to transition to a “high” level, which then in turn causes the second node  1450  to transition to a “low” level. Subsequently, from such a state, the first node  1444  is discharged to a “low” state in accordance with a time constant set by the resistor  1452  and the capacitor  1446 . The cycling continues so that the resulting frequency signal ϕ 1  is produced. As an example, the resistance of the resistor  1452  can be 10 k ohms, and the capacitance of the capacitor  1446  can be 0.1 microfarads, and the resulting frequency for the resulting frequency signal ϕ 1  is then about in a range of about 0-400 Hertz. The Schmitt trigger inverter  1448  can be implemented by a CD74HC14 chip, for example. Hence, the radiation-to-frequency converter  1440  can produce a digital output which has a frequency dependent on the amount of impinging radiation. The digital output is also produced in a power-efficient manner. In one embodiment, power-efficiency results because the Schmitt trigger inverter  1448  is power efficient, the capacitor  1446  is rather small, and the resulting frequency signal ϕ 1  is low. Power consumption can be further reduced by only periodically supplying power to some or all of the components of the radiation-to-frequency converter  1440 , or more generally, the radiation monitoring system  1400 . 
       FIG.  14 D  is a schematic diagram of a latch  1450  according to one embodiment of the invention. The latch  1450  represents a detailed embodiment for the latch  1428  shown in  FIG.  14 B . The latch  1450  includes a first NAND gate  1452  and a second NAND gate  1454 . These NAND gates  1452  and  1454  are connected as shown in  FIG.  14 D . 
       FIG.  14 E  is a schematic diagram of a LCD driver  1460  according to one embodiment of the invention. The LCD driver  1460  represents a detailed embodiment for the LCD driver  1430  illustrated in  FIG.  14 B . The LCD driver  1460  includes a diode  1462  having a cathode terminal that receives the enable signal (EN) from the latch  1450 , and an anode terminal that couples to a first node  1464 . The LCD driver  1460  also includes a capacitor  1466  that couples between the first node  1464  and ground. Additionally, the LCD driver  1460  includes a first Schmitt trigger inverter  1468  coupled between the first node  1464  and a second node  1470 , and a second Schmitt trigger inverter  1472  connected to the second node  1470 . In addition, a resistor  1474  couples the first node  1464  and the second node  1470 . The output of the LCD driver  1460  is provided from the second node  1470  and from the output of the second Schmitt trigger inverter  1472 . These outputs are the designed to excite the appropriate one or more LCD elements of the LCD display  1432  so as to produce the desired output indication. As an example, the resistance of the resistor  1474  can be 330 k ohms, and the capacitance of the capacitor  1446  can be 0.1 microfarads, and the resulting frequency for the outputs (when enabled) is then about 200 Hertz. The Schmitt trigger inverters can be implemented by a CD74HC14 chip, for example. It should be noted that LCD driver  1460  is designed to excite a single LCD element or a single group of LCD elements. Hence, in cases in which the output indication is to excite multiple LCD elements at different times, additional circuitry would be required. 
       FIG.  14 F  is a schematic diagram of a power supply  1475  according to one embodiment of the invention. The power supply  1475  represents a detailed embodiment of the power supply  1434  illustrated in  FIG.  14 B . 
     The power supply  1475  includes a battery  1476  that is coupled between a positive voltage terminal (V+) then a negative voltage terminal (B−). The power supply  1475  also includes a transistor  1477 . In one embodiment, the transistor  1477  is an enhancement type n-channel MOSFET. The drain terminal of the transistor  1477  is coupled to the ground terminal of the power supply  1475 , and a source terminal of the transistor  1477  is coupled to the negative voltage terminal (B−). A gate terminal of the transistor  1477  couples to a first node  1478 . The first node  1478  is coupled to the negative voltage terminal (B−) by a capacitor  1479 - 1 , and is coupled to the positive voltage terminal (V+) by a resistor  1479 - 2  and a switch S 2   a . The switch S 2   a  is closed when the power supply  1475  is “on.” The power supply  1475  also includes a switch S 2   b  that is closed when the power supply  1475  is “off.” Hence, only one of the switches S 2   a  and S 2   b  are closed at any one point. When the switch S 2   b  is closed, the first node  1478  is coupled to the negative voltage terminal (B−) so that the transistor  1477  is “off.” On the other hand, when the switch S 2   a  is closed, the first node  1478  is able to hold a positive voltage which activates the transistor  1477 . When the transistor  1477  is activated, the negative voltage provided on the negative voltage terminal (B−) is provided at the ground (GND) terminal. As an example, the resistance of the resistor  1479 - 2  can be 100 k ohms, and the capacitance of the capacitor  1479 - 1  can be 0.01 microfarads, and the battery can provide 3 Volts (e.g., 35 mA-H). The transistor  1477  can be implemented by a 2N708 chip, for example. 
     In one embodiment, a radiation detector can be mounted on a substrate and couple to other circuitry so that radiation monitoring can be performed. The manner in which the radiation detector is mounted to the substrate can vary with implementation. In one implementation, the substrate is a printed circuit board (PCB) that supports not only the radiation detector but also the other circuitry.  FIGS.  14 G- 14 I  illustrate examples of a few possible implementations in the case where the radiation detector is a UV detector; however, other implementations can be utilized. 
       FIG.  14 G  is a cross-sectional view of a UV detector arrangement  1480  according to one embodiment of the invention. The UV detector arrangement  1480  is formed on a printed circuit board  1481  that contains a hole (or opening)  1482 . A phototransistor  1483  is placed in the hole  1482 . A base  1484  for the phototransistor  1483  is used to electrically connect the phototransistor  1483  to the printed circuit board  1481  via solder  1485 . A film of aluminized Mylar  1486  is attached to the top of the printed circuit board  1481  at the hole  1482 . The aluminized Mylar  1486  serves as a sensitivity reducer since it generally attenuates the radiation (e.g., UV or IR radiation) that impinges on the phototransistor  1483 . The aluminized Mylar  1486  can be attached to the printed circuit board  1481  by an adhesive, such as epoxy. Attached to the top of the aluminized Mylar  1486  is an aluminum sheet  1487  with an opening  1488 . The opening  1488  corresponds to, but has a substantially smaller diameter than the hole  1482 . Hence, the aluminum sheet  1487  further restricts radiation (i.e., restricts volume of radiation) impinging on the phototransistor  1483 . An optical filter  1489  is placed over the aluminum sheet  1487  at the vicinity of the hole  1482 . As an example, the optical filter  1489  primarily passes UV radiation. The UV radiation then is limited by the opening  1488  in the aluminum sheet  1487 , attenuated by the aluminized Mylar  1486 , and then the attenuated UV radiation is sensed by the phototransistor  1483 . The aluminum sheet  1487  and the optical filter  1489  can be attached with an adhesive, such as epoxy. 
     Optionally, the back side of the printed circuit board  1481  at the vicinity of the phototransistor  1483  can attenuate or block radiation that might otherwise impinge on and be sensed by the phototransistor  1483 . As shown in  FIG.  14 G , an aluminum sheet  1491  can be attached to the back side of the printed circuit board  1481  behind the phototransistor  1483 . The aluminum sheet  1491  can be attached with an adhesive, such as epoxy. 
     Finally, the top of the UV detector arrangement  1480 , except for the optical filter  1489 , can be encapsulated by a top encapsulant  1490 . For example, the top encapsulant  1490  can be epoxy. The bottom of the UV detector arrangement  1480  can be encapsulated by a bottom encapsulant  1492 . For example, the bottom encapsulant  1492  can be epoxy. The epoxy used for the encapsulant  1490  or  1492  can be opaque (e.g., block epoxy) to further assist in blocking radiation. 
       FIG.  14 H  is a cross-sectional view of a UV detector arrangement  1480 ′ according to one embodiment of the invention. The UV detector arrangement  1480 ′ is formed on a printed circuit board  1481  that contains a hole (or opening)  1482 . A phototransistor  1483  is placed in the hole  1482 . A base  1484  for the phototransistor  1483  is used to electrically connect the phototransistor  1483  to the printed circuit board  1481  via solder  1485 . A film of aluminized Mylar  1486  is attached to the top of the printed circuit board  1481  at the hole  1482 . The aluminized Mylar  1486  serves as a sensitivity reducer since it generally attenuates the radiation that impinges on the phototransistor  1483 . The aluminized Mylar  1486  can be attached to the printed circuit board  1481  by foil tape  1493  (that uses an adhesive). The foil tape  1493  does not cover the region of the aluminized Mylar  1486  above the phototransistor  1483 . The foil tape  1493  further restricts radiation (i.e., restricts volume of radiation) impinging on the phototransistor  1483 . Attached to the top of the foil tape  1493  is an optical filter  1489  at the vicinity of the hole  1482 . Foil tape  1494  (that uses an adhesive) can be used to hold the optical filter  1489  in position. The foil tape  1494  may also serve to restrict radiation impinging on the phototransistor  1483 . As an example, the optical filter  1489  primarily passes UV radiation. The UV radiation can then be limited by the opening in the foil tapes  1493  and  1494  as well as the aluminized Mylar  1486 . A cavity  1497  in the hole  1482  above the phototransistor  1483  can be filled with an epoxy, such as clear epoxy. 
     Optionally, the back side of the printed circuit board  1481  at the vicinity of the phototransistor  1483  can attenuate or block radiation that might otherwise impinge on and be sensed by the phototransistor  1483 . As shown in  FIG.  14 H , a foil tape  1496  can be attached to the back side of the printed circuit board  1481  behind the phototransistor  1483 . A bottom cavity  1498  between the back side of the printed circuit board  1481  and the foil tape  1496  can be filled with an opaque substance, e.g., block epoxy, to further assist in attenuating or blocking radiation. 
       FIG.  14 I  is a cross-sectional view of a UV detector arrangement  1480 ″ according to one embodiment of the invention. The UV detector arrangement  1480 ″ shown in  FIG.  14 I  is generally similar to the UV detector arrangement  1480 ′ shown in  FIG.  14 H , except that the UV detector arrangement  1480 ″ does not use the optical filter  1489  or the foil tape  1494 . In such an embodiment, an optical filter (such as the optical filter  1489 ) is not required because the spectral response of the phototransistor  1483 ′ is appropriate without filtering or because a coating provided on the phototransistor  1483 ′ or its housing (package) effectuates similar filtering and obviates the need for a separate optical filter (such as the optical filter  1489 ). 
     The phototransistor  1483  or  1483 ′ shown in  FIGS.  14 G- 14 I  can be a photodiode as noted elsewhere in this patent application. In addition, the phototransistor  1483  or  1483 ′ (or photodiode) can have a height greater than the thickness of the printed circuit board  1481 . 
       FIG.  14 J  is a partial block diagram of a radiation monitoring system  3000  according to one embodiment of the invention. The radiation monitoring system  3000  represents one implementation of a portion of the radiation monitoring system  1400  illustrated in  FIG.  14 A  or a portion of the radiation monitoring system  1420  illustrated in  FIG.  14 B . In particular, the radiation monitoring system  3000  provides reduced power operation. The reduced power operation can substantially extend battery life. In this embodiment, a radiation-to-frequency converter  3002  receives a low duty cycle signal V D . The low duty cycle signal V D  causes the radiation-to-frequency to periodically operate briefly. The duty cycle and frequency for the low duty cycle signal V D  can vary with implementation. 
       FIG.  14 K  is a schematic diagram of a radiation-to-frequency converter  3010  and a sensor according to one embodiment of the invention. The radiation-to-frequency converter  3010  is generally similar to the radiation-to-frequency converter  1440  illustrated in  FIG.  14 C . However, the radiation-to-frequency converter  3010  uses a photodiode  3012  instead of the phototransistor  1442 . Also, the resistor  1452  and the diode  1454  illustrated in  FIG.  14 C  are typically not needed as the photodiode  3012  is a diode and often includes an internal resistance. One example of such a photodiode is Everlight PD-15-22 (another is Everlight PD-93-21), though various different photodiodes can be used, and an optical filter may be used with the photodiode. Additionally, the radiation-to-frequency converter  3010  also include a transistor  3014 . The transistor  3014  is controlled by the low duty cycle signal V D  such that the low power operation results. Namely, only when the low duty cycle signal V D  is “low” is significant power being consumed by the radiation monitoring system to monitor radiation. As a result, the radiation monitoring system can operate under battery power for extended durations. 
       FIG.  14 L  is a diagram of a representative waveform  3020  of a low duty cycle signal V D . The low duty cycle signal V D  is “low” much less than it is “high.” In this embodiment, radiation monitoring occurs when low duty cycle signal V D  is “low.” Hence, the on time for a periodic low duty cycle signal V D  is denoted t ON  and the off time is denoted t OFF . As an example, the on time t ON  can be 0.5 seconds, while the off time t OFF  can be 128 seconds (which is a duty cycle of 256 to 1. 
       FIG.  14 M  is a schematic diagram of a power supply  3040  according to one embodiment of the invention. The power supply  3040  represents a detailed embodiment for a power supply that could be an alternative design for the power supply  1434  illustrated in  FIG.  14 B . 
     The power supply  3040  includes a battery  3042  that is coupled between a positive voltage terminal (B+) and ground terminal (GND). The power supply  3040  includes an on/off switch S 3 . When the switch S 3  is closed the power supply is turned on. In one implementation, the switch S 3  is a push button switch that is normally open (i.e., not close). The power supply  3040  also includes a resistor  3044  and a transistor  3046 . In one embodiment, the transistor  3046  is an enhancement type p-channel MOSFET. The drain terminal of the transistor  3046  is coupled to the ground terminal (GND) of the power supply  3040  via a resistor  3048 , and a source terminal of the transistor  3046  is coupled to the positive voltage terminal (B+) of the battery  3042 . A gate terminal of the transistor  3046  is coupled to a first node  3049 . The first node  3049  is coupled to the positive voltage terminal (B+) by the resistor  3044 , and can be coupled to the ground terminal (GND) via the switch S 3 . The power supply  3040  also includes a transistor  3050 , having a gate terminal coupled to a second node  3051 , a source terminal connected to the ground terminal (GND), and a drain terminal connected to a third node  3052 . In one embodiment, the transistor  3050  is an enhancement type n-channel MOSFET. Further, the power supply  3040  includes a transistor  3054 , a resistor  3056  and a capacitor  3058 . In one embodiment, the transistor  3054  is an enhancement type p-channel MOSFET. The gate terminal of the transistor  3054  connects to the third node  3052 , the source terminal of the transistor  3054  connects to the positive voltage terminal (B+), and the drain terminal of the transistor  3054  connects to a voltage output terminal (V+). The resistor  3056  and the capacitor  3058  are connected in parallel between the positive voltage terminal (B+) and the third node  3052 . 
     The operation of the power supply  3040  can be briefly explained as follows. When the switch S 3  is press (momentarily), the transistor  3046  pulls the second node  3051  to approximately the positive voltage terminal (B+), which activates the transistor  3050 . When the transistor  3050  is activated, the third node is pulled to approximately ground, which activates the transistor  3054 . When the transistor  3054  is activated, the voltage output terminal (V+) is capable of outputting power for use by other circuitry. Since the switch S 3  is soon released, the transistors  3046  and  3050  deactivate. However, the transistor  3054  remains on for a period of time determined by a time constant determined by the resistor  3056  and the capacitor  3058 . Hence, during the period of time, charge from the capacitor  3058  is slowly discharged. Once substantially discharged, the transistor  3054  deactivates, thus ceasing output of any power to the other circuitry. In effect, the power supply  3040  automatically turns off after the period of time. As an example, the period of time can be 12 hours (e.g., representing daily usage of a radiation monitoring system). The power supply  3040  can also receive a reset signal that serves to restart any “auto-off” timing that may be used. 
     It should be noted that a power supply for a radiation monitoring system can implemented in various ways. The power supply  1475  illustrated in  FIG.  14 F  uses an “on” switch and an “off” switch. The power supply  3040  in  FIG.  14 M  uses a single “on” switch (e.g., push button) and an “auto-off” feature. In still another embodiment, the power supply, and thus the radiation monitoring system, can always be powered on. With CMOS transistor devices, the power consumption is relatively low such that a radiation monitoring system could be battery powered for an extended period of time without the need to recharge or replace the battery (i.e., long battery life). When the radiation monitoring is only briefly performed periodically, such as discussed above with reference to  FIGS.  14 J,  14 K and  14 L , the power consumption is particularly low and the battery life can be particularly long. 
       FIG.  14 N  is a diagram of a binary counter  4000  according to one embodiment of the invention. The binary counter  4000  is, for example, suitable for use as at least a portion of the divider  1426  illustrated in  FIG.  14 B . As an example, the binary counter  4000  can be a 26-bit counter. The inputs to the binary counter  4000  include the frequency signal ϕ 1  from a radiation-to-frequency converter (e.g., radiation-to-frequency converter  1424 ), a reset signal (such as from a switch S 1 ), and an enable signal. The switch S 1  is, for example, a push-button type switch. The binary counter  4000  can have a plurality of output lines (e.g., twenty-six (26) output lines), of which five such lines Q 19  through Q 24  are illustrated. These output are representative outputs that might be utilized by subsequent circuitry to control an output device. However, it should be understood that other output lines could alternatively be used. The enable input to the binary counter  4000  permits the binary counter to count when “high” but stops the binary counter  4000  from counting when “low.” 
       FIG.  14 O  is a block diagram of latch-driver circuitry  4100  according to one embodiment of the invention. In one embodiment, the latch-driver circuitry  4100  can correspond to the latch  1428 , the LCD driver  1430  and the LCD display  1432  as shown in  FIG.  14 B . 
     In this embodiment, the latch-driver circuitry  4100  has the capability to separately drive a plurality of different segments. These segments can be segments of a LCD display and can be combined to form symbols or charts. For example, in one embodiment, the LCD segments can be utilized to form a bar graph output. 
     The latch-driver circuitry  4100  includes a latch  4102  that receives an input associated with output Q 19  from a divider (e.g., the binary counter  4000 ). The output of the latch  4102  is supplied to a LCD driver  4104 . The LCD driver  4104  includes NAND gates  4106  and  4108 . The outputs of the NAND gates  4106  and  4108  are supplied to a LCD segment- 1   4110 . The LCD driver  4104  also includes frequency signals ϕ 2  and/ϕ 2  from an oscillator  4112 . 
     The latch-driver circuitry  4100  further includes a latch  4114 , a LCD driver  4116  and a LCD segment- 2   4418 . The latch  4114  receives an input signal associated with the output Q 20  from the divider (e.g., the binary counter  4000 ). Likewise, for one or more other outputs from the divider (e.g., the binary counter  4000 ), the latch-driver circuitry  4100  can include a latch, a LCD driver and a LCD segment. In this regard, the output Q N  from the divider represents a generic output signal which is supplied to a latch  4120 . The output of the latch  4120  is supplied to a LCD driver  4122 . The output of the display driver  4122  is coupled to a LCD segment-N  4124 . Additionally, each of the latches  4102 ,  4114  and  4120  receives a reset signal from a switch S 1 . 
     Still further, the output Q N  is coupled to an enable terminal of the divider (e.g., the binary counter  4000 ) via an inverter  4126 . When the signal Q N  is high, the LCD segments are fully illuminated; hence, the enable signal output by the inverter  4126  is “low” so that the divider (e.g., the binary counter  4000 ) is disabled, until reset. 
       FIG.  14 P  is a block diagram of driver circuitry  4200  according to one embodiment of the invention. The driver circuitry  4200  is coupled to one or more outputs from a divider (e.g., the binary counter  4000 ). In this illustrated embodiment, the driver circuitry  4200  couples to the outputs Q 20  and Q 21 . 
     The driver circuitry  4200  includes a LCD driver  4202  that receives the outputs Q 20  and Q 21  from the divider (e.g., the binary counter  4000 ). These signals Q 20  and Q 21  are supplied to a NOR gate  4206  whose output is supplied to NAND gates  4208  and  4210 . The outputs of the NAND gates  4208  and  4210  are supplied to a LCD graphic segment- 1   4204 . As shown in  FIG.  14 P , the LCD graphic segment- 1   4204  represents a “happy” smiley face. 
     Additionally, the output Q 20  is supplied to a LCD driver  4212  whose output in turn drives a LCD graphic segment- 2   4214 . Further, the output Q 21  is supplied to a LCD driver  4216  whose output in turn drives a LCD graphic segment- 3   4218 . As shown in  FIG.  14 P , the LCD graphic segment- 2   4214  is a “neutral” smiley face, and the LCD graphic segment- 3   4248  is a “sad” smiley face. It should be understood that various other graphical symbols or images can be used in place of smiley faces. 
     The driver circuitry  4200  also includes an oscillator  4220  that supplies the output frequency signals ϕ 2  and/ϕ 2  to the LCD drivers  4202 ,  4212  and  4216 . The driver circuitry  4200  further includes an inverter  4222  coupled to the output Q 21 . The output of the inverter  4222  is coupled to the enable terminal of the divider (e.g., the binary counter  4000 ) so that the divider (e.g., the binary counter  4000 ) is stopped once the output Q 21  is “high.” 
       FIG.  14 Q  is a block diagram of driver circuitry  4300  according to another embodiment of the invention. In this embodiment, the output is a numerical value. In one embodiment, the driver circuitry  4300  can correspond to the latch  1428 , the LCD driver  1430  and the LCD display  1432  as shown in  FIG.  14 B . 
     In this embodiment, the driver circuitry  4300  has the capability to separately drive a plurality of different segments. These segments are segments of a LCD display and can be combined to form numerical values. For example, in one embodiment, the segments can be utilized to output numerical values from 0-9. In other embodiments, the range of numerical outputs could be more or less than 0 through 9. 
     The driver circuitry  4300  receives a plurality of outputs from a divider (e.g., the binary counter  4000 ), such as outputs Q 19 , Q 20 , Q 21  and Q 22 . These outputs are supplied to a BCD-to-7 segment converter  4302 . The output of the converter  4302  is supplied to a 7-segment LCD driver  4304 . The 7-segment LCD driver  4304  couples to a 7-segment display  4306 . Here, the outputs from the divider (e.g., the binary counter  4000 ) are converted such that a numerical range is output on the 7-segment display  4306 . For example, the 7-segment display  4306  can display a number from 0 to 9 indicating a quantity or intensity of radiation. A NAND gate  4308  is coupled to the output Q 19  and the output Q 22  so as to decode a value of “9” at the outputs and cause the enable signal to go “low”, thereby ceasing operation of the divider (e.g., binary counter  4000 ) when such reaches its maximum value. 
     The radiation monitoring system can also be implemented by primarily digital design.  FIG.  14 R  is a block diagram of a radiation monitoring system  4400  according to another embodiment of the invention. The radiation monitoring system  4400  uses a microcontroller  4402  and can be considered a primarily digital implementation. As an example, the radiation monitoring system  4400  can implement functions similar to the radiation monitoring system  1400  shown in  FIG.  14 A  as well as the radiation monitoring system  1420  shown in  FIG.  14 B , using either radiation-to-frequency techniques or, alternatively, radiation-to-pulse-width techniques. However, the flexibility provided by the digital implementation is not limited to implementing these particular techniques. 
     In addition to the microcontroller  4402 , the radiation monitoring system  4400  includes a battery  4404  and a capacitor  4406 . The battery  4404  provides power to the microcontroller  4402 . The capacitor  4406  together with the sensor  1422  and the microcontroller  4402  can be used to monitor radiation. The microcontroller  4402  also determines whether and what to display on the LCD panel  1432 . In one implementation, the microcontroller  4402  can include a display driver for driving the LCD panel  1432 . One example of a suitable microcontroller for the microcontroller  4402  is the 4-bit microcontroller TM8704 available from Tenx Technology, Inc. 
     In one embodiment, the monitoring of radiation by the radiation monitoring system  4400  is performed using a pulse-width measurement technique. In such an embodiment, periodically, the microcontroller  4402  outputs a HIGH signal (digital “1” signal) on an OUTPUT pin and then monitors an INPUT pin for a HIGH signal. In one implementation, the sensor  1442  is implemented by a photodiode having its anode connected to the INPUT pin and its cathode connected to the OUTPUT pin. When the photodiode detects radiation, the photodiode conducts. Then, the HIGH signal on the OUTPUT pin propagates to the INPUT pin and charges up the capacitor  4406 . The higher the intensity of the radiation, the faster the capacitor  4406  is charged to the HIGH signal. The duration of time between the outputting of the HIGH signal on the OUTPUT pin and the detection of a HIGH signal on the INPUT pin is dependent on the radiation intensity detected by the sensor  1422  and the capacitance of the capacitor  4406 . The microcontroller  4402  measures this duration of time. The radiation intensity measured by the microcontroller  4402  is thus inversely proportional to the period of time. An intensity value can be computed as a value that is proportional to a constant divided by the period of time. This intensity value is then accumulated with the prior accumulated intensity value to determine a current accumulated intensity value. The current accumulated intensity value is then compared to one or more threshold levels to determine an output indication to be displayed on the LCD panel  1432 . As discussed elsewhere in this patent application, the output indication can take many different forms. One exemplary form is a series of increasing bars that are activated as the accumulated current intensity value exceeds a corresponding series of threshold levels. 
     In one embodiment, upon turn-on of the radiation monitoring system  4400 , such as via a switch (SW 1 )  4408 , the current accumulated intensity value maintained by the microcontroller  4402  can be cleared or set to zero. Hence, the turn-on can also act as a reset. In an alternative embodiment, the current accumulated intensity value could be very gradually reduced to provide a slow discharge of the accumulated intensity value as a function of time. In the alternative embodiment, the current accumulated intensity value need not be reset. 
     In one embodiment, to assist in the efficient power utilization of the radiation monitoring system  4400 , the microcontroller  4402  can be placed in a low power state when not acquiring a radiation measurement. This can be achieved by a sleep, halt or stop mode or other approaches to reduce power consumption. Then, periodically the microcontroller would briefly operate in an active or non-low power state to acquire and accumulate the radiation measurement. The periodicity can vary with implementation, such as from fifteen (15) seconds to fifteen (15) minutes. The greater the period the longer battery life, but the less the accuracy. A reasonable solution might use a period on the order of about three (3) minutes. In acquiring the period of time (for the radiation measurement), a maximum time-out can be provided so that power is not wasted. Typically, if the radiation monitoring system is monitoring light or UV radiation in the dark (or for UV, the environment has very low UV, such as at night or inside a car with windows closed), then the time period being measured would time-out. Thereafter, if desired, the periodicity by which re-measurement is performed can be made longer so as to further conserve power. In another embodiment, once the radiation monitoring system  4400  is turned-on, it can remain on for a predetermined period of time and then automatically turn itself off (or enter a very low power mode). For example, after being turned-on with no user input for eight (8) hours, the radiation monitoring system  4400  can automatically turn itself off. 
     The radiation monitoring system  4400  can also include a second switch (SW 2 )  4410  to enable a user&#39;s skin type to be selected. For example, the second switch  4410  can provide different switch positions for different skin types (e.g., light, medium and dark). The switch position can affect the various threshold levels that are used when comparing with the current accumulated intensity value to determine an output indication to be displayed on the LCD panel  1432 . As an example, when the output indication is presented as a series of five segments (S 1 -S 5 ) of increasing bars that are activated as the accumulated current intensity value exceeds a series of threshold levels, Table I provided below provides illustrative threshold levels for various skin types. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                   
                 TABLE I 
               
               
                   
                   
               
               
                   
                 Skin Type 
                 S1 
                 S2 
                 S2 
                 S4 
                 S5 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Light 
                 .25 
                 .5 
                 1 
                 2 
                 4 
               
               
                   
                 Medium 
                 .5 
                 1 
                 2 
                 4 
                 8 
               
               
                   
                 Dark 
                 1 
                 2 
                 4 
                 8 
                 16 
               
               
                   
                   
               
            
           
         
       
     
     The times (durations) provided in Table I are in units of hours and are times for the various segments of the LCD panel to activate in the presence of medium-to-light radiation (e.g., UV index (UVI) of about 3). It should be noted that if the radiation present were greater than medium-to-light, then these times in Table I would be shorter. Likewise, if the radiation present were less than medium-to-light, then these times in Table I would be longer. 
       FIGS.  15 A,  15 B and  15 C  are radiation detection systems according to different embodiments of the invention. These radiation detection systems are described in the context of UV radiation detection (which uses a UV sensor); however, it should be understood that these radiation detection systems can be also be used to detect other types of radiation. This can be accomplished, for example, by replacing the UV sensor in the radiation detection system with another type of sensor, such as an infrared sensor or light sensor. These UV detection systems are compact modular systems. The UV detection systems can be built on a single substrate that is designed to be inserted into an end product. Since the UV detection system is compact and modular, the end product need only have an opening, cavity or container to hold or encompass the UV detection system. As such, the end product can quickly be transformed into an end product capable of providing UV monitoring. Advantageously, in one embodiment, the UV detection system is such that has minimal impact on design of the end product and no tedious wiring is required. For example, in case in which the end product is an eyeglass frame, a temple of the eyeglass frame can have an opening, cavity or container to hold or encompass the UV detection system, whereby no other changes or complications to the eyeglass frames need be imposed. Other such end-products can include: hats, shoes, tee-shirts, swimming-suits, key rings, purses, beverage can holders, and other consumer products. 
       FIG.  15 A  is a cross-sectional diagram of a UV detection system  1500  according to one embodiment of the invention. The UV detection system  1500  is build on a substrate  1502 . The substrate  1502  can be a printed circuit board, a flexible tape or film (e.g., Kapton® polyimide film), ceramic, and the like, as known in the art. The UV detection system  1500  includes a power source  1504 , an UV sensor  1506 , electrical circuitry  1508  and a display device  1510  (e.g., LCD or LED). The display device  1510  is one type of output device, so it should be recognized that other embodiments can utilize other types of output devices. The power source  1504  is, for example, a battery or a solar panel of one or more solar cells. For example, if the power source  1504  is a battery, the battery can be a coin battery, such as often used in electronic watches. In one embodiment, the UV sensor  1506  includes a phototransistor. In one embodiment, the electrical circuitry  1508  includes one or more of analog electrical components (e.g., capacitors, resistors, diodes, transistors) or integrated circuits. Any such integrated circuits can be provided in a variety of packages, but surface mount packages can help maintain a thin profile for the UV detection system  1500 . The various electrical components can be wire bonded onto the substrate  1502 . For example, a SiC or GaN phototransistor (or photodiode) can serve as at least part of a UV sensor and be wire bonded onto the substrate  1502  or other electrical component. The UV detection system  1500  shows components of the system mounted to both sides of the substrate  1502 . 
       FIG.  15 B  is a cross-sectional diagram of a UV detection system  1520  according to another embodiment of the invention. The UV detection system  1520  can utilize the same or similar components as the UV detection system  1500 . However, unlike the UV detection system  1500 , the UV detection system  1520  mounts all components on one side of the substrate  1502 . The effect of the UV detection system  1520  is a thinner module, though the substrate  1502  may be longer, as compared to the UV detection system  1500  shown in  FIG.  15 A . 
       FIG.  15 C  is a cross-sectional diagram of a UV detection system  1540  according to another embodiment of the invention. The UV detection system  1540  can utilize the same or similar components as the UV detection system  1500 . However, unlike the UV detection system  1500 , the UV detection system  1540  mounts the UV sensor  1506  at or near the edge of the substrate  1502 . This has the potential advantage of positioning the UV sensor  1506  in a position so that it is better able to receive incident radiation (e.g., sunlight). The mounting of the UV sensor  1506  with respect to the substrate  1502  can also be flexible so that the UV sensor  1506  can be positioned, such as angularly positioned with respect to the substrate  1502  and/or angularly oriented when assembled into an opening, cavity or container of an end-use product. For example, the UV sensor  1506  could be soldered onto the substrate  1502  tipped at an angle. Alternatively, a small prism could be mounted on top of the UV sensor  1506 , providing an angled direction of sensitivity. For example, the prism could be formed in place by filling a small, angled, box with clear optical adhesive (such as epoxy) that, when set would provide a prism, efficiently-coupled to the UV sensor  1506 . 
     The UV sensor  1506  utilized in the UV detection systems  1500 ,  1520  and  1540  may use an optical filter with an optical sensor. For example, the optical sensor can respond to light, UV and infrared radiations, and the sensitivity of the optical filter causes the optical sensor to capture primarily the target radiation (e.g., UV) wavelengths of light. Hence, the UV sensor  1506  can include such optical filter. For example, the optical filter can be implemented as a coating on the optical filter. Alternatively, the optical filter can also be a separate component that is positioned proximate to the optical sensor when the end product is assembled. In other words, an optical filter can be another component of the UV detection system, or can be a separate component that is inserted when assembled into the end product. In one embodiment, an optical adhesive can be used to secure the optical filter to the optical sensor. 
       FIG.  16 A  is a cross-sectional view of an eyewear housing  1600  containing a UV detection system according to one embodiment of the invention. Here, the eyewear housing  1600  can represent a portion of the temple region of a frame for a pair of glasses. Typically, the portion of the temple region is forward of the user&#39;s ear (i.e., towards the lens holders) when the glasses are being worn. The UV detection system contained within the eyewear housing  1600  is, for example, the UV detection system  1500  shown in  FIG.  15 A . The eyewear housing  1600  has an opening, cavity or container to receive the UV detection system. The eyewear housing  1600  also has a first opening  1602  and a second opening  1604 . The first opening  1602  is aligned with the power supply  1504 , which would in such an embodiment be a solar panel. Hence, the first opening  1602  can allow light to impinge on the solar panel. The second opening  1604  is aligned with the display device  1510  so that information displayed can be seen. The eyewear housing  1600  also includes an optical filter  1606  that is positioned proximate to the UV sensor  1506 . In one embodiment, the optical filter  1606  is a separate component that inserted into an opening in the eyewear housing  1600  that is proximate (e.g., adjacent) to the UV sensor  1506 . In another embodiment, the optical filter  1606  is integral with the UV sensor  1506 . 
       FIG.  16 B  is a cross-sectional view of an eyewear housing  1620  containing a UV detection system according to another embodiment of the invention. The eyewear housing  1620  has an opening, cavity or container to receive the UV detection system, such as the UV detection system  1500  shown in  FIG.  15 A . The eyewear housing  1620  also has a first window  1622  and a second window  1624 . The first window  1622  is aligned with the power supply  1504 , which would in such an embodiment be a solar panel. Hence, the first window  1622  can allow light to impinge on the solar panel. The second window  1624  is aligned with the display device  1510  so that information displayed can be seen. The eyewear housing  1600  also includes a third window  1626 . The third window  1626  is positioned proximate to the UV sensor  1506 . The third window  1626  can, in one embodiment, operate as an optical filter for the UV sensor  1506 . The first and second windows  1622  and  1624  can be clear or colored so long as adequate light passes through. 
       FIG.  16 C  is a cross-sectional view of an eyewear housing  1640  containing a UV detection system according to still another embodiment of the invention. The eyewear housing  1640  is generally similar to the eyewear housing  1620  illustrated in  FIG.  16 B . However,  FIG.  16 C  illustrates one way to secure the UV detection system within the portion of the temple region of the eyewear housing  1640 . In particular, the eyewear housing  1640  include a stand  1642  and an adhesive material  1644 . When assembled, the UV detection system can be placed within the temple region of the eyewear housing  1640  and positioned against the stand  1642 , then the adhesive  1644  can be provided within the temple region to secure the UV detection system in position. The adhesive can vary widely, such as glue, double-stick tape, silicone rubber, epoxy, etc. 
       FIG.  16 D  is a cross-sectional view of an eyewear housing  1660  containing a UV detection system according to yet still embodiment of the invention. The eyewear housing  1660  is generally similar to the eyewear housing  1600  illustrated in  FIG.  16 A , except that the electrical circuitry  1508  may be repositioned on the substrate  1502  and a switch base  1662  and a switch  1664 , such as a button switch, are provided. As shown in  FIG.  16 D , the switch base  1662  can attach to the substrate  1502  and thereby support the switch  1664  that protrudes outside of the eyewear housing  1660  (or is otherwise accessible) so that a user can activate the switch (e.g., press the button). 
       FIG.  16 E  is a cross-sectional view of an eyewear housing  1670  containing a radiation monitoring system according to one embodiment of the invention. The eyewear housing  1670  includes a substrate  1502 , such as a printed circuit board. The UV sensor  1506 , more generally a radiation sensor, can be placed in an opening or indentation of the substrate  1502 , or on the substrate  1502 . The optical filter  1606  is provided proximate to the radiation sensor which is also adjacent to an opening  1672  in the eyewear housing  1670 . As an example, the eyewear housing  1670  can correspond to a temple of a pair of eyeglasses. The electrical circuitry  1508  can also be attached to the substrate  1502 . In this embodiment, the electrical circuitry  1508  includes an integrated circuit chip  1674  that is attached or bonded to a first side of the substrate  1502  (e.g., printed circuit board). As an example, the integrated circuit chip  1674  can be a microcontroller, such as the microcontroller  4402  illustrated in  FIG.  14 R . The display device  1510  can be attached to a second side of the substrate. For example, the display device  1510  can be a LCD panel. Optionally, the opening  1672  can contain an optical element, such as a lens, to focus radiation onto the radiation sensor, thereby broadening sensitivity to the angle of incident radiation. broadening angle sensitivity. The optical element may also service as a radiation attenuator and/or an optical filter. For example, a tinted diffuser dome can act as a lens and an attenuator. Hence, if such an optical element is used, the optical element may obviate the need for the separate optical filter  1606 . More generally, the optical filter  1606  may not be necessary when the sensitivity of the radiation sensor is adequate to limit the measurement to the desired radiation. Although not shown in  FIG.  16 E , the radiation monitoring system could also typically include a power source, such as a battery or solar cell, one or more switches, and additional electrical circuitry  1508  (e.g., capacitor) besides the integrated circuit chip  1674 . 
     In general, the UV detection system according to the invention can make use of zero or more switches. One type of switch is a button switch, such as a push-button switch. As an example, the switch can serve as a reset switch, an on/off switch, or an on (and reset) switch. 
       FIG.  17 A  is a cross-sectional view of a module housing  1700  according to one embodiment of the invention. As shown in  FIG.  17 A , the module housing  1700  can operate as a housing for the UV detection system  1500  shown in  FIG.  15 A . The module housing  1700  includes a first window  1702  and a second window  1704 . The first window  1702  can be proximate to the display device  1510 , and the second window  1704  can be proximate to the power supply  1504 , which would in such an embodiment be a solar panel. The first and second windows  1702  and  1704  can be clear or colored so long as adequate light passes through. In one embodiment, the thickness of the first and second windows  1702  and  1704  is greater than the thickness of the walls of the module housing  1700 . The module housing  1700  can also include an opening  1706  that is positioned proximate to the UV sensor  1506 . Still further, although not illustrated in  FIG.  17 A , the module housing  1700  can further include one or more vents or holes so that air can circulate through the module housing  1700 . Alternatively, the module housing  1700  does not include vents or holes, so as to be water-resistant or water-proof. 
     The module housing  1700  is a housing for a module, such as a UV detection system. The module housing  1700  is then placed into an opening, cavity or container of an eyewear housing, such as a temple region of the eyewear housing. The module housing  1700  protects the module. The module housing  1700  can also be used to regularize or standardize the form factor for the UV detection system, such that the opening, cavity or container of the eyewear housing can be regularized or standardized. 
       FIG.  17 B  is a cross-sectional view of an eyewear housing  1720  according to one embodiment of the invention. The eyewear housing  1720  has an opening, cavity or container  1721  for receiving the module housing  1700 . As shown in  FIG.  17 B , the module housing  1700  is contained by the eyewear housing  1720 . The eyewear housing  1720  includes an opening  1722  that corresponds to the first window  1702  of the module housing  1700 . The eyewear housing  1720  also includes an opening  1724  that corresponds to the second window  1704  of the module housing  1700 . Still further, the eyewear housing  1720  can optionally further include an optical filter  1726  corresponding to the third opening  1706  of the module housing  1700  (and thus proximate to the UV sensor  1506 ). The module housing  1700  can, for example, be held in position with respect to the eyewear housing  1720  by an adhesive or by an interference fit. 
       FIG.  18    is a cross-sectional view of an eyewear housing  1800  having a reflective-type filter according to one embodiment of the invention. Here, the eyewear housing  1800  can represent a temple region of a frame for a pair of glasses. Typically, a large percentage of the temple region is in front of the user&#39;s ear when the glasses are being worn. The eyewear housing  1800  has an internal cavity  1802  where a circuit board  1804  is provided. Electrically coupled to the circuit board  1804  are a UV detector  1806  (e.g., based on a photodetector), electrical circuitry  1808 , a display device (e.g., LED, LCD)  1810 , and solar cell(s)  1812 . As a result, the circuit board  1804  and the UV detector  1806 , the electrical circuitry  1808 , the display device  1810  and the solar cell(s)  1812  are within the internal cavity  1802  and thus embedded within the eyewear housing  1800 . 
     A UV reflector  1814  is mounted on an internal support  1816 . Light impinges on the UV reflector  1814  via an opening  1818  in the eyewear housing  1800 . The opening  1818  allows radiation to pass through to the UV reflector  1814 . In one embodiment, there can be a piece of transparent material at the opening  1818  to prevent dust or dirt from getting through the opening  1818  into the internal cavity  1802 . The opening  1818  can also be considered a transparent region in the eyewear housing  1800 . The UV reflector  1814  selectively reflects primarily the UV portion of the radiation towards the UV detector  1806 . As a result, the reflector  1814  serves as a reflective-type filter, that is, a type of optical filter. For example, the reflector  1814  can be made of a material that substantially reflects UV light but does not reflect non-UV light. An example of one such reflector is known as a UV hot mirror. Also, the eyewear housing  1800  can also include transparent portions  1820  and  1822  which are adjacent to the display device  1810  and the solar cell(s)  1822 , respectively. The transparent portion  1820  allows light from the display device  1810  to be seen from the outside of the eyewear housing  1800 . The transparent portion  1822  allows light from an external light source to impinge on the solar cell(s)  1812 . Alternatively, the display device  1810  could extend to and conform with an outer surface of part of the eyewear housing  1800 , and the solar cell(s)  1812  could extend to and confirm with an outer surface of part of the eyewear housing  1800 . Alternatively, if a battery were used in place of the solar cell(s)  1822 , then the transparent portion  1822  would not be needed. 
     In one embodiment, a number of previously described transparent regions, portions, or sheets of materials, such as the transparent portions  1820  and  1822  in  FIG.  18   , can be translucent (including partially translucent). Still another alternative is that the eyewear housing  1800  could be primarily translucent. 
     The optical sensor or UV sensor can receive impinging light from a variety of different directions (i.e., angle of incidence) depending on implementation. For example, the light can come from an opening in the top of the temple, such as shown in  FIG.  18   , or at a side of the temple, such as shown in  FIGS.  16 A- 16 C and  17 B . As another example, the light can come from an opening at an angle between the top and the side of the temple. Typically, the optical sensor or the UV detector would be aligned with the opening at whatever angle it takes, such alignment tends to maximize sensitivity of the optical sensor or the UV detector. The optimal angle can also be based on the latitude. Thus, at the equator, the UV detector should point upward. And at the north pole, the sensor should point horizontally. In one embodiment, the size of the opening can be larger to increase impinging light, or can be smaller to decrease impinging light. In another embodiment, the opening can be flared outward so as to increase the amount of impinging light. Further, the opening can also support a lens for focusing impinging light. 
     The UV detection system can also have a “being-worn” switch as noted above. In one embodiment, the “being-worn” switch enables the UV monitoring system to automatically determine when to monitor UV radiation and when not to monitor UV radiation. In particular, the UV radiation can be monitored when an eyeglass frame having the UV detection system is “being-worn” and not when the eyeglass frame is not “being-worn.” The “being-worn” switch can be positioned in the temple portion with the other components of the UV detection system. In one embodiment, the UV detection system is provided, as a module as noted above, and which further includes a switch. The switch can, for example, be a “being worn” switch. By having the switch in the module, the manufacture and assembly of the end-product having the UV detection system can be simplified. As examples, the “being-worn” switch can be an optical, magnetic or mechanical switching device. 
     The “being-worn” switch can make use of the situation that the temples are in an open position when the eyeglass frame is being worn, and in a closed position when not being worn. In one embodiment, the “being-worn” switch can be positioned at a temple proximate to a region that couples the temple to its corresponding lens holder. For example, the UV detection system (e.g., module) can be provided within the temple region near the end of the temple so that the “being worn” switch is adjacent the lens portion of the eyeglass frame. 
       FIG.  19    is a side view of a temple  1900  for an eyeglass frame according to one embodiment of the invention. The side view of  FIG.  19    shows an outer side of the temple  1900 , namely, the side of the temple  1900  that faces outward when being worn. The temple  1900  includes therein a UV detection system  1902  internal to the temple  1900 . A window  1904  is provided in the temple  1900  for light (e.g., sunlight) to impinge on a UV sensor of the UV detection system  1902 . The window  1904  can also provide some optical filtering effects, such as noted above. Although not shown in  FIG.  19   , the temple  1900  may also have a window or opening for a solar panel. At a forward end  1906  of the temple  1900  where a hinge is typically provided, a pin  1908  is exposed. The pin  1908  passes through an opening at the forward end  1906  of the temple  1900 . The pin  1908  is coupled to a switch internal to the temple  1900  and part of the UV detection system  1902 . When the pin  1908  is not depressed, as shown in  FIG.  19   , the switch informs the UV detection system  1902  that the eyeglass frame is closed, i.e., not being worn. On the other hand, when the eyeglass frame is opened, i.e., presumably being worn, the pin  1908  is depressed by the forward end  1906  abutting against a portion of its corresponding lens holder, thereby informing the UV detection system  1902  that the eyeglass frame is opened. In one embodiment, the pin  1908  is only depressed when the temple  1900  of the eyeglass frame is fully opened, such that the eyeglass frame would almost necessarily be worn (particularly when there is a bias against the eyeglass frame being fully open). 
       FIGS.  20 A and  20 B  are top view diagrams of a portion of an eyeglass frame  2000  according to one embodiment of the invention. The eyeglass frame  2000  includes a lens holder  2002  and a temple  2004 . The temple  2004  includes a UV detection system therein. The UV detection system includes an opening or window  2006  that corresponds to an optical sensor used by the UV detection system. The optical sensor is used as a “being-worn” switch. When the eyeglass frame  2000  is in the open position as shown in  FIG.  20 A , the optical sensor detects significant light, thereby informing the UV detection system that the eyeglass frame  2000  is presumably being worn. On the other hand, when the eyeglass frame  2000  is in the closed position as shown in  FIG.  20 B , the opening or window  2006  is covered by a flap  2008  provided on the lens holder  2002 . When the flap  2008  covers the opening or window  2006 , no significant light can be detected by the optical sensor. In such case, the UV detection system is informed that the eyeglass frame  2000  is not being worn. 
       FIG.  21    is a side view of a temple  2100  for an eyeglass frame according to one embodiment of the invention. The side view of  FIG.  21    shows an inner side of the temple  2100 , namely, the side of the temple  2100  that faces inward when being worn. The temple  2100  includes therein a UV detection system  2102  internal to the temple  2100 . The temple  2100  may also have a window or opening (not shown) that corresponds to an output device (e.g., display). A window or opening  2104  is provided at a rearward portion of the temple  2100 . The window or opening  2104  corresponds to an optical sensor (internal to the temple  2100 ) provided at the window or opening  2104 . The window or opening  2104  allows light (e.g., sunlight) to impinge on the optical sensor. The optical sensor is coupled to the UV detection system  2102  via one or more electrical wires  2106 . When the temple  2100  of the eyeglass frame is being worn by a user, the optical sensor will be blocked from receiving significant amounts of light, thereby informing the UV detection system  2102  that the eyeglass frame is being worn. For example, the optical sensor can be blocked by the user&#39;s head or hair when the eyeglass frame is being worn. On the other hand, when the temple  2100  of the eyeglass frame is not being worn by a user, the optical sensor will receive significant amounts of light, thereby informing the UV detection system  2102  that the eyeglass frame is not being worn. Of course, at night often little or no light will impinge on the optical sensor. Optionally, in such case the lack of any significant light (e.g., detected by another optical sensor or solar cell) can be used to ensure that the UV detection system does not operate at night, such that the eyeglass frame can be considered not being worn at night (even if being worn at night). 
       FIG.  22    is a side view of a temple  2200  for an eyeglass frame according to another embodiment of the invention. The side view of  FIG.  22    shows an outer side of the temple  2200 , namely, the side of the temple  2200  that faces outward when being worn. The temple  2200  includes therein a UV detection system  2202  internal to the temple  2200 . Although not shown in  FIG.  22   , the temple  2200  may also have windows or openings for a solar panel and/or an optical sensor. At a forward end  2204  of the temple  2200 , a magnetic switch  2206  is provided. The magnetic switch  2206  is internal to the temple  2200  and part of the UV detection system  2202 . The magnetic switch  2206  can use a magnet to provide a switch. The magnetic switch  2206  switches from a first position to a second position when a metallic material is adjacent the forward end  2204  of the temple  2200 . For example, such metallic material can be provided in a portion of a lens holder that abuts the forward end  2204  when the temple  2200  is in the open position. Here, when the switch is in the open position, the metallic material is adjacent the forward end  2204  of the temple  2200 , and the UV detection system  1902  understands that the eyeglass frame is opened, i.e., presumably being worn. In such case, the switch can be considered to be in the second position. On the other hand, when the eyeglass frame is closed, i.e., not being worn, the switch is in the first position because the metallic material is no longer adjacent the forward end  2204  of the temple  2200 . Then, the UV detection system  2202  understands that the eyeglass frame is closed (i.e., not being worn). In one embodiment, the magnetic switch  2206  can be implemented by a Hall effect sensor. Alternatively, it should be understood that the magnetic switch could be provided at a portion of a lens holder that abuts the forward end  2204  when the eyeglass frame has the temple  2200  open, and the metallic material could be at the forward end  2204 . 
     The “being worn” switch can also be used by a user to signal the UV detection system to provide its output at an output device, such as a display device. For example, when the “being worn” switch is initially closed (i.e., being worn), the UV detection system can output its text or graphical output to the display device. Typically, the displayed output would be displayed only for a limited period of time (e.g., 10 seconds). Such an approach is power efficient, yet permits the user to obtain the output information when desired. Alternatively, another switch (e.g., dedicated output switch) could be used to cause the output to be displayed for a limited period of time or while the switch is depressed. 
     The UV detection system can also make use of one or more switches to change operational settings, such as threshold levels, output type, user preferences, user physical characteristics (e.g., skin type), accumulation mode or non-accumulation mode, activation/deactivation of auxiliary sensors. 
     The UV detection system can make use of one or more variable capacitors or resistors within the design of the electronic circuit to facilitate a manufacturer or dispenser to calibrate the UV detection. Such can assist with quality control as well as consistency or uniformity. The UV detection system can also alter another aspect of the electronic circuitry, such as a count or divide amount ( FIG.  14 B ), to calibrate the UV detection. 
     Calibration or customization of the UV detection system can also be performed after manufacturer by a user or dispenser. As one example, the eyewear can be sold or dispensed with one or more stickers available for placement over the radiation detector (e.g., UV sensor). The stickers can attenuate the radiation impinging on the radiation detector. In other words, the stickers can perform sensitivity adjustment on the UV detection system. Different ones of the stickers can offer different degrees of attenuation. A user can thus select an appropriate sticker based on their skin type (or amount of exposure they prefer) and place it over the radiation detector, thereby calibrating or customizing the UV detection system to the user. 
     As previously noted, the optical sensor (e.g., UV sensor) can be implemented by at least one photodetector, such as a phototransistor. Although various different phototransistors can be utilized, one example of a suitable phototransistor is Part No. PT100MCOMP available from Sharp Microelectronics of the Americas. As another example, a suitable phototransistor for the phototransistor is Part No. EL-PT15-21B (1206 phototransistor) available from Everlight Electronics Co., Ltd. As still another example, other suitable phototransistors are GaN or SiC phototransistors. Alternatively, although the discussion above at times refers to phototransistors, the photodetector can also be a photodiode. In the case of a photodiode, similar circuitry to that noted above would be utilized. Although various different photodiodes can be utilized, one example of a suitable photodiode is Part No. PD100MCOMP available from Sharp Microelectronics of the Americas. 
     The radiation sensors or detectors, including phototransistors and photodiodes, used for radiation monitoring are often designed for sensing or detecting certain types of radiation. For example, a UV sensor or UV detector would be an electronic device that is sensitive to UV radiation, namely, the wavelengths of light pertaining to UV spectrum. While such electronic device may be primarily sensitive to such radiation of interest (e.g., UV radiation), they may also be somewhat sensitive to other radiation. Optical filters can be used to assist these sensors or detectors in sensing the desired type of radiation. Nevertheless, radiation monitoring can be achieved even though the radiation sensors or detectors are sensitive to non-desired radiation so long as they are primarily or principally responsive to the desired radiation. 
     When the radiation to be monitored is UV radiation, the optical filter described above is typically implemented by a material that passes radiation in the UV wavelength band and blocks radiation not in the UV wavelength band. Various materials can be used in this regard. In one embodiment, the material providing the optical filtering can be known as a UV cold mirror. However, in another embodiment, the optical filter may have other characteristics, such as a material (e.g., polycarbonate) that passes radiation not in the UV wavelength band and blocks radiation in the UV wavelength band. In another embodiment, the optical filter can utilize a material that passes light primarily associated with the ultraviolet wavelength range while substantially blocking light of other wavelengths. Such a material can, for example, be a filter made from quartz-glass with nickel oxide, such is commonly known as Wood&#39;s glass. The material implementing the optical filter can also be configured in various ways, such as a plug for an opening or a coating on a surface (or on the photodetector itself). In one embodiment, the material implementing the optical filter can either pass or reflect the UV radiation. 
     An output (e.g., notification, such as a warning) to the user can vary in content and type. The type can be visual and/or audio. The content can be numerical, graphical, musical, textual, synthesized text, etc. A progression of warnings can be used to give more substantial warning (such as when prior warnings are ignored). The output can also be predetermined, dynamically determined or configurable. Still further, the output can be dependent on user preferences, user physical characteristics (e.g., skin type), auxiliary sensor information (e.g., location), and degree of health risk. 
     The radiation monitoring system can also include one or more connectors with the eyewear. The connectors can, for example, facilitate electrical or mechanical interconnection with an external electrical device (e.g., computing device, media player, headset, power source). Although the format and size of the connectors can vary, in one embodiment, the connector is a standard audio connector or a peripheral bus connector (e.g., USB connector). 
     The radiation monitoring system can also include one or more switches with the eyewear. The switches can, for example, facilitate user input or control with respect to the radiation monitoring system. For example, the switches can provide one or more of on/off, reset, on, on (and reset), and calibration. One example of a calibration switch is a skin type switch that provides switch positions for different skin types (e.g., light, medium and dark). The radiation monitoring system can also provide a user with an indication of whether the system is currently on or off, such as by a graphical image on a display device or by a LED. 
     A radiation monitoring system can also include a memory. The memory can be volatile or non-volatile. The memory can also be removable or non-removable with respect to the eyewear. If the memory is volatile, the radiation monitoring system could include a battery to provide power to the memory so that stored data (e.g., accumulated radiation, user preferences, etc.) can be retained even when adequate solar energy is not available. As an example, the presence of a memory can allow storage of radiation information for an extended period of time to acquire a historical understanding of radiation information. 
     In one embodiment, an eyeglass frame can include memory that can store acquired radiation information, such stored radiation information can be subsequently uploaded to a computer, in a wired or wireless manner. The radiation information can then be analyzed by the computer. For example, a doctor may require a patient to keep track of his exposure to UV radiation, or other radiations, to assist the doctor to evaluate risks or symptoms. 
     In another embodiment, a user of an eyeglass frame interact with a switch provided on the eyeglass frame to set a calibration level. As an example, in the case of UV radiation, the calibration level can correspond to the user&#39;s skin type. In general, the calibration level causes the amount of acceptable radiation (e.g., threshold levels) to vary. 
     In still another embodiment, a user can go through a calibration procedure when the user purchases the eyeglasses. The calibration procedure can operate to personalizes the UV detection system for the user. For example, the complexion of the user&#39;s skin affects the user&#39;s sensitivity to UV. Based on the skin complexion, a UV monitoring system adjusts the levels of acceptable exposure to UV. The calibration procedure can be performed wired or wirelessly. For example, the calibration can be done by a computer, with the calibration data downloaded to the eyeglasses through a connector integral with the eyeglasses. 
     A radiation monitoring system can also include a communication module. The communication module would allow data transmission to and from the radiation monitoring system (namely, the eyewear) and an external device. The data being transmitted can, for example, be radiation information, configuration data, user preferences, or auxiliary sensor data. The data transmission can be wireless or wireline based. The eyewear can further include a connector operatively connected to the radiation monitoring system. Such a connector can facilitate data transmission with respect to the radiation monitoring system or the eyewear. 
     A temple of a pair of glasses can be removable of the remainder of the frame. Such facilitates replacement of temples. For example, a convention temple could be removed from a frame and replaced with a temple having a least one electrical component at least partially embedded therein. 
     A radiation monitoring system can be partially or fully contained in a temple arrangement associated with a temple of a pair of glasses. In one embodiment, the temple arrangement can be removable from the temple. A temple arrangement can be a temple tip, a temple cover or a temple fit-over. 
     A radiation monitoring system can be partially or fully tethered to a pair of glasses. For example, some of the components for monitoring radiation or one or more auxiliary sensors can be tethered to the eyewear. In one embodiment, the tethered components can be tethered at the neck or upper back region of the user. Tethering components allows for increased design freedom with the eyewear as well as additional area with which to house the components. 
     Still further, a radiation monitoring system could be partially or completely within a device or a base that can be tethered to eyewear. 
     A number of embodiments have been described above for an eyeglass frame, i.e., primary frame. Such embodiments are also applicable to an auxiliary frame. An auxiliary frame can attach to a primary frame through different techniques, such as using clips. Another technique to attach an auxiliary frame to a primary frame is by way of magnets. Examples of using magnets as an attachment technique can be found, for example, in U.S. Pat. No. 6,012,811, entitled, “EYEGLASS FRAMES WITH MAGNETS AT BRIDGES FOR ATTACHMENT.” 
     Although much of the discussion above concentrates on UV monitoring, the invention is generally applicable to radiation monitoring. The radiation can, for example, pertain to one or more of UV, infrared, light and gamma radiation. Light, namely visible light, can be referred to as ambient light. 
     Also, the above discussion concerning UV sensor or UV monitor is generally applicable to radiation sensors or monitors. One embodiment of a radiation sensor or monitor which principally measures light is a light sensor or a light monitor. More particularly, in measuring light, sunlight is a dominant source of light, such that a radiation sensor or monitor which principally measures light can be referred to as a sun sensor or a sun monitor. In such case, radiation monitoring can be considered light monitoring or sunlight monitoring. 
     Visible light is part of everyday life and is generally not considered harmful to persons. In one embodiment, the measurement of light can be used to infer a measurement of harmful radiation (e.g., UV radiation). 
     A number of embodiments have been described where a radiation monitoring system is embedded in a temple of an eyeglass frame. However, in other embodiments, the radiation monitoring system can be in other parts of the eyeglass frame, such as the bridge or lens holder region. Also, for eyewear having shield(s) or wrap-around lenses, the radiation monitoring system can also be in such shield(s) or lenses. 
     Although much of the above discussion pertains to providing radiation (e.g., radiation) monitoring capabilities in eyewear, it should be understood the any of the various embodiment, implementations, features or aspects noted above can also be utilized is other or on end products besides eyewear. Examples of other such end-products can include: hats (e.g., soft hats, hard-hats, helmets), watches or watch bands, bracelets, bracelet accessories, necklaces, necklace accessories, rings, shoes (e.g., sandals, athletic shoes, beach shoes), shoe accessories, clothing (e.g., tee-shirt, swimming-suit, ties, pants, jackets, etc.), belts, belt accessories, zippers, key rings, purses, beach-tags, containers (e.g., cups, bottle, tube—such as a sun tan lotion bottle or tube); container holders (e.g., can holders, coasters, coolers, etc.), and other consumer products. 
       FIGS.  23 A- 23 G  illustrate examples of various end products having radiation monitoring capability.  FIG.  23 A  illustrates a hat  2300  having a radiation monitoring system  2302 . The radiation monitoring system  2302  can be attached to or embedded within the hat  2300 .  FIG.  23 B  illustrates a watch  2304  having a radiation monitoring system  2302 . The watch  2304  can have a base  2306  and a band  2308 . The radiation monitoring system  2302  can be coupled to the band  2308  as illustrated in  FIG.  23 B . Alternatively, the radiation monitoring system  2302  can be coupled to the base  2306 .  FIG.  23 C  illustrates a shirt  2310  having a radiation monitoring system  2302 . As shown in  FIG.  23 C , in one embodiment, the radiation monitoring system  2302  can be placed in the upper, chest, back or shoulder region of the shirt  2310 .  FIG.  23 D  illustrates a shoe  2312  having a radiation monitoring system  2302 . The radiation monitoring system  2302  can, for example, be placed at the top, upper portion of the shoe  2312 .  FIG.  23 E  illustrates a key chain  2314  having a radiation monitoring system  2302 .  FIG.  23 F  illustrates a bracelet or necklace  2316  having a radiation monitoring system  2302 .  FIG.  23 G  illustrates a bottle or tube  2318  having a radiation monitoring system  2302 . 
     If the end product is soft or made of cloth (e.g., clothing, purse, hat, etc.), then the radiation monitoring system (e.g., provided as a module) can be sewn onto the cloth or adhered to the cloth using an adhesive (e.g., adhesive tape). The module, or a case for the module, can have thin flanges about its periphery which can be easily sewn onto the cloth. The case for the radiation monitoring system can be molded into its desired shape (e.g., injection molded, compression molded or vacu-formed). The case can be soft (vinyl, thin polypropylene, soft polyurethane, or PET). Typically, if flanges are utilized for sewing, they would be thin and soft. Alternatively, the case can be hard (e.g., PVC, polypropylene, nylon, polycarbonate, or styrene). If the end product is hard, the case can also be hard. 
     When the end product is a container, such as the bottle or tube  2318  shown in  FIG.  23 G , the radiation monitoring system  2302  can be attached to the bottle or tube  2318  or can be molded into the bottle or tube  2318 . In one embodiment, the bottle or tube  2318  is a plastic container. The radiation monitoring system  2302  is particularly well suited to be attached or integral with a bottle or tube, often plastic, that contains sun tan lotion. Sun tan lotion includes sun tan or sun block lotions, including sun tan or sun block oils. 
     The various embodiments, implementations and features of the invention noted above can be combined in various ways or used separately. Those skilled in the art will understand from the description that the invention can be equally applied to or used in other various different settings with respect to various combinations, embodiments, implementations or features provided in the description herein. 
     The invention can be implemented in software, hardware or a combination of hardware and software. A number of embodiments of the invention can also be embodied as computer readable code on a computer readable medium. The computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, magnetic tape, optical data storage devices, and carrier waves. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. 
     The advantages of the invention are numerous. Different embodiments or implementations may yield one or more of the following advantages. One advantage of the invention is that radiation monitoring can be inconspicuously performed in conjunction with eyewear. Another advantage of the invention is that electrical components for radiation monitoring can be embedded within a frame (e.g., temple) of eyewear. Still another advantage of the invention is that radiation monitoring can be intelligently performed such that it operates only at likely appropriate times to improve accuracy and usefulness. Yet another advantage of the invention is that eyewear may further include one or more auxiliary sensors that can cause additional output to be provided to the user. 
     Numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the invention may be practiced without these specific details. The description and representation herein are the common meanings used by those experienced or skilled in the art to most effectively convey the substance of their work to others skilled in the art. In other instances, well-known methods, procedures, components, and circuitry have not been described in detail to avoid unnecessarily obscuring aspects of the present invention. 
     In the foregoing description, reference to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Further, the order of blocks in process flowcharts or diagrams representing one or more embodiments of the invention do not inherently indicate any particular order nor imply any limitations in the invention. 
     The many features and advantages of the invention are apparent from the written description and, thus, it is intended by the appended claims to cover all such features and advantages of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation as illustrated and described. Hence, all suitable modifications and equivalents may be resorted to as falling within the scope of the invention.