The prior art includes many lighting systems for receptacles such as cases, handbags and other travel bags. The prior art lighting systems are designed to provide light when the receptacle is open and to turn off the light when the receptacle is closed. Some prior art systems are manually operated other systems include some level of automation. Many of these systems suffer various shortcomings individually or in combination thereof. Some of the shortcomings include: high energy usage, resulting in either short battery life or a large heavy battery; creating too much heat, which could damage articles stored in the receptacles; not providing adequate lighting; actuation by a mechanical switch, which either requires manual switching or is prone to breakage; and using light sensors for automatic switching of the light, the light sensors being typically unreliable and do not operate well in some light conditions. Some of the prior art systems are permanently attached to a particular receptacle and therefore a new lighting system needs to be purchased for each receptacle.

There is therefore a need for an energy efficient, low heat, high light intensity lighting system for a receptacle having a reliable automatic light sensitive switching operation.

SUMMARY OF THE INVENTION The present invention is a portable lighting system and method of operation thereof.

According to the teachings of the present invention there is provided, a lighting system, comprising: (a) a housing; (b) an LED mechanically connected to the housing; (c) a light sensor arrangement mechanically connected to the housing, the light sensor arrangement configured for producing an output signal in response to incident light; and (d) a controller mechanically connected to the housing, the controller being electrically connected to the light sensor arrangement and the LED, the controller being configured for: (i) receiving the output signal from the light sensor arrangement; (ii) storing the output signal; (iii) comparing the output signal to at least one previously stored output signal of the light sensor arrangement; and (iv) turning on and off the LED in response to a result of the comparing.

According to a further feature of the present invention, the step of comparing is performed by comparing the output signal to an average of previously stored output signals of the light sensor arrangement.

According to a further feature of the present invention, the step of turning on and off is performed when the output signal differs by more than a predetermined proportion of the at least one previously stored output signal.

According to a further feature of the present invention, the housing includes a battery compartment having two electrical contacts for connection to a battery, the electrical contacts being electrically connected to the controller.

According to a further feature of the present invention, there is also provided an attachment arrangement configured for reversibly attaching the housing to a receptacle.

According to a further feature of the present invention, there is also provided a control switch mechanically connected to the housing, the controller being configured for performing two functions, the functions including a first function and a second function, wherein: (a) the first function includes turning on the LED when the output signal exceeds a value; (b) the second function includes turning on the LED when the output signal falls below a value; and (c) the control switch is configured for selecting one of the functions.

According to a further feature of the present invention, there is also provided an attachment arrangement mechanically connected to the housing, the attachment arrangement being configured for mechanically connecting the housing to another portable lighting device.

According to a further feature of the present invention, the second attachment arrangement includes a line.

According to a further feature of the present invention, the attachment arrangement includes at least one of a strip of hooks and a strip of loops.

According to a further feature of the present invention, the housing is substantially hemispherical.

According to a further feature of the present invention, there is also provided an attachment arrangement mechanically connected to the housing, the attachment arrangement including a magnet configured for reversibly attaching the housing to a receptacle due to a magnetic force between the magnet and a metal element of the receptacle.

According to a further feature of the present invention, there is also provided an attachment arrangement including at least one pin, the housing having at least one opening

therein, the attachment arrangement being configured such that the housing is reversibly attached to a receptacle via pressure fitting a part of the pin into the opening of the housing.

According to a further feature of the present invention, there is also provided a lens mechanically connected to the housing, the lens being configured for focusing incident light on to the light sensor arrangement.

According to a further feature of the present invention, the LED is configured for producing substantially only infrared light.

According to the teachings of the present invention there is also provided a portable lighting system, comprising: (a) a housing including a battery compartment having two electrical contacts for connection to a battery; (b) an LED mechanically connected to the housing; (c) a light sensor arrangement mechanically connected to the housing, the light sensor arrangement configured for producing an output signal in response to light incident on the light sensor arrangement; (d) a controller mechanically connected to the housing, the controller being electrically connected to the light sensor arrangement, the LED and the electrical contacts, the controller being configured for performing two functions, the functions including a first function and a second function, wherein: (i) the first function includes turning on the LED when the output signal exceeds a value; and (ii) the second function includes turning on the LED when the output signal falls below a value; and (e) a control switch mechanically connected to the housing, the control switch being configured for selecting one of the functions.

According to a further feature of the present invention, there is also provided an attachment arrangement configured for reversibly attaching the housing to a receptacle.

According to the teachings of the present invention there is also provided a portable lighting system, comprising two portable lighting devices, each of the portable lighting devices having: (a) a housing including a battery compartment having two electrical contacts for connection to a battery; (b) a first attachment arrangement mechanically connected to the housing, the first attachment arrangement being configured for mechanically connecting the portable lighting devices together; (c) an LED mechanically connected to the housing; (d) a light sensor arrangement mechanically connected to the housing, the light sensor arrangement configured for producing an output signal in response to light incident on the light sensor arrangement; and (e) a controller mechanically connected to the housing, the controller being electrically connected to the light sensor arrangement, the electrical contacts and the LED, the controller being configured for turning on and off the LED in response to the output signal.

According to a further feature of the present invention, there is also provided a second attachment arrangement configured for reversibly attaching the housing of at least one of the portable lighting devices to a receptacle.

According to a further feature of the present invention, the second attachment arrangement includes a line.

According to a further feature of the present invention, the first attachment arrangement includes at least one of a strip of hooks and a strip of loops.

According to a further feature of the present invention, the housing is substantially hemispherical.

According to the teachings of the present invention there is also provided a portable lighting system for a receptacle including a metal element, comprising: (a) a housing including a battery compartment having two electrical contacts for connection to a battery; (b) an attachment arrangement mechanically connected to the housing, the attachment arrangement including a magnet configured for reversibly attaching the housing to the receptacle due to a magnetic force between the magnet and the metal element of the receptacle; (c) an LED mechanically connected to the housing; (d) a light sensor arrangement mechanically connected to the housing, the light sensor arrangement configured for producing an output signal in response to light incident on the light sensor arrangement; and (e) a controller mechanically connected to the housing, the controller being electrically connected to the light sensor arrangement, the electrical contacts and the LED, the controller being configured for turning on and off the LED in response to the output signal.

According to the teachings of the present invention there is also provided a portable lighting system for a receptacle, comprising: (a) a housing having at least one opening therein, the housing including a battery compartment having two electrical contacts for connection to a battery; (b) an attachment arrangement including at least one pin, the attachment arrangement being configured such that the housing is reversibly attached to the receptacle via pressure fitting a part of the pin into the opening of the housing; (c) an LED mechanically connected to the housing; (d) a light sensor arrangement mechanically connected to the housing, the light sensor arrangement configured for producing an output signal in response to light incident on the light sensor arrangement; and (e) a controller mechanically connected to the housing, the controller being electrically connected to the light sensor arrangement, the electrical contacts and the LED, the controller being configured for turning on and off the LED in response to the output signal.

According to the teachings of the present invention there is also provided a lighting system for a receptacle, comprising: (a) a housing; (b) an LED mechanically connected to the housing; (c) a light sensor arrangement mechanically connected to the housing, the light sensor arrangement configured for producing an output signal in response to light incident on the light sensor arrangement; (d) a lens mechanically connected to the housing, the lens being configured for focusing incident light on to the light sensor arrangement; (e) a controller mechanically connected to the housing, the controller being electrically connected to the light sensor arrangement and the LED, the controller being configured for turning on and off the LED in response to the output signal.

According to a further feature of the present invention, the housing includes a battery compartment having two electrical contacts for connection to a battery, the electrical contacts being electrically connected to the controller.

According to a further feature of the present invention, there is also provided an attachment arrangement configured for reversibly attaching the housing to a receptacle.

According to the teachings of the present invention there is also provided an infrared lighting system for a receptacle, comprising: (a) a housing; (b) a light source mechanically connected to the housing, the light source being configured for producing substantially only infrared light; (c) a light sensor arrangement mechanically connected to the housing, the light sensor arrangement configured for producing an output signal in response to light incident on the light sensor arrangement; (d) a controller mechanically connected to the housing, the controller being electrically connected to the light sensor arrangement and the infrared light source, the controller being configured for turning on and off the infrared light source in response to the output signal.

According to a further feature of the present invention, the housing includes a battery compartment having two electrical contacts for connection to a battery, the electrical contacts being electrically connected to the controller.

According to a further feature of the present invention, there is also provided an attachment arrangement configured for reversibly attaching the housing to a receptacle.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein: Fig. 1 is an isometric view of a portable lighting system that is constructed and operable in accordance with a preferred embodiment of the present invention; Fig. 2 is a plan view of the lighting system of Fig. 1 ; Fig. 3 is an isometric view of the lighting system of Fig. 1 having the top cover partially cut-away; Fig. 4 is an isometric view of the lighting system of Fig. 1 with the top cover completely removed; Fig. 5 is a flow chart showing the steps of operation of the controller of the lighting system of Fig. 4; Fig. 6 is an isometric view showing the base of the lighting system of Fig. 1; Fig. 7 is a cross-sectional view of a first alternate attachment arrangement for use with the lighting system of Fig. 1; Fig. 8 is a cross-sectional view of a second alternate attachment arrangement for use with the lighting system of Fig. 1 ; and Fig. 9 is an isometric view of the lighting system of Fig. 1 attached back-to-back to another substantially same lighting system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is a portable lighting system construction and method of operation thereof.

The principles and operation of a portable lighting system according to the present invention may be better understood with reference to the drawings and the accompanying description.

Reference is now made to Figs. 1 to 4. Fig. 1 is an isometric view of a portable lighting system 10 that is constructed and operable in accordance with a preferred embodiment of the present invention. Fig. 2 is a plan view of system 10 of Fig. 1. Fig. 3 is an isometric view of system 10 of Fig. 1 having a top cover 12 partially cut-away. Fig. 4 is an isometric view of system 10 of Fig. 1 with top cover 12 completely removed. System 10 includes a housing 14 having top cover 12 and a base 16. Top cover 12 has a substantially hemispherical form and is formed from a translucent plastic. However, it will be appreciated by those ordinarily skilled in

the art that top cover 12 can also be formed from a clear plastic. Base 16 is substantially flat and is typically formed from an opaque plastic. Base 16 includes three clips 18 disposed around the perimeter of base 16. Clips 18 are configured to engage into three corresponding notches 20 on the outside edge of top cover 12 thereby reversibly mechanically connecting top cover 12 to base 16. Top cover 12 is detached from base 16 when a battery 24 of system 10 needs to be installed or replaced. Housing 14 includes a battery compartment 22 having two electrical contacts 26 for connection to battery 24. Battery 24 is typically a button battery. It will be appreciated by those ordinarily skilled in the art that the voltage of battery 24 will depend on the other components of system 10.

System 10 includes a disk shaped circuit board 28. Circuit board 28 is mechanically connected to base 16 of housing 14. Circuit board 28 includes, disposed thereon, two light sources 30, a light sensor arrangement 32, a controller 34, and a control switch 36. Light sources 30, light sensor arrangement 32, controller 34 and control switch 36 are mechanically connected to base 16 of housing 14 via circuit board 28. Controller 34 is electrically connected to electrical contacts 26 of battery compartment 22, light sources 30, light sensor arrangement 32 and control switch 36. The functions of light sources 30, light sensor arrangement 32, controller 34 and control switch 36 are described below in more detail.

Light sources 30 are typically light emitting diodes (LED's) emitting visible light, preferably SMT technology LED's printed onto circuit board 28. LED's have many advantages of other light sources. In particular, LED's provide a low heat and low energy source of bright light. Suitable LED's for system 10 are widely commercially available, for example, from OSRAM Opto Semiconductors GmbH of Wernerwerkstrasse 2, D-93049, Regensberg, Germany.

In accordance with an alternate embodiment of the present invention, light sources 30 are configured for producing substantially only infrared light. In such a case light sources 30 are typically two infrared LED's. The term"substantially only"is defined herein to include producing a small amount of visible light which is not noticeable by a passerby looking at the receptacle. However, it will be appreciated by those ordinarily skilled in the art that infrared light can be produced using a"white"light LED with a suitable infrared filter, which could be incorporated into top cover 12. The articles in the receptacle are therefore illuminated with infrared light. Therefore, in a dark environment, the viewer needs to wear night vision goggles in order to see the articles in the receptacle. This application is particularly useful when the owner of the receptacle does not want others to see the articles or the light from light sources 30, for example, but not limited to military usage.

Light sensor arrangement 32 is configured for producing an output signal in response to incident light. Light sensors are available which produce either an analogue or digital output signal. More advanced light sensors can predict the lighting level more accurately under certain light conditions, such as ambient lighting conditions using advanced techniques by using multiple digital sensors as part of a single light sensor arrangement. When the light sensor arrangement includes more than one light sensor the output signal typically includes an output signal from each of the various light sensors. Therefore, term"output signal"is defined herein to include a combined output signal (with or without additional processing) formed from a plurality of output signals associated with the output signals of each sensor of a multiple sensor light sensor arrangement. Suitable light sensors are widely commercially available, for example, from OSRAM Opto Semiconductors GmbH mentioned above and Agilent Technologies, Inc. <BR> <BR> <P>Headquarters of 395 Page Mill Rd. , Palo Alto, CA and TAOS Inc of 800 N. Jupiter Rd. , Suite 205, Plano, Texas. Light sensor arrangement 32 typically has an associated light sensor circuit 40 for processing the output signal. Light sources 30 and light sensor arrangement 32 are arranged on circuit board 28 so that light sources 30 and light sensor arrangement 32 face different directions. Typically light sources 30 and light sensor arrangement 32 are arranged so that there is at least 90 degrees, preferably at least 135 degrees, angular displacement between the lines of optimal operation of light sources 30 and light sensor arrangement 32. In use, system 10 is disposed in a receptacle so that light sensor arrangement 32 faces towards the entrance of the receptacle and light sources 30 face down into the receptacle. Light sources 30 face down for two reasons. First, in order to avoid glaring the user of the receptacle. Second, the light is needed to illuminate the articles and not elsewhere. System 10 includes a lens 38 mechanically connected to top cover 12 of housing 14. Lens 38 is typically integrally formed with top cover 12. However, it will be appreciated by those ordinarily skilled in the art that lens 38 could be formed as a separate element and then attached to top cover 12. Lens 38 is configured for focusing incident light onto light sensor arrangement 32. The focal length of lens 38 depends on the size of the sensor (s) of light sensor 32 as well as the distance between lens 38 and light sensor 32. Lens 38 also indicates the position of light sensor arrangement 32 beneath top cover 12 and therefore the user knows how to position system 10 so that light sensor arrangement 32 faces the entrance of the receptacle and light sources 30 faces into the receptacle, as described above.

Controller 34 in general terms is configured for turning on and off light sources 30 in response to the output signal of light sensor arrangement 32. Controller 34 is configured for

performing two alternate functions, a first function and a second function. The first function includes controller 34 turning on light sources 30 when the output signal of light sensor arrangement 32 exceeds a value. Similarly, light sources 30 are turned off when the output signal of light sensor arrangement 32 drops below a value. The second function includes controller 34 turning on light sources 30 when the output signal of light sensor arrangement 32 falls below a value. Similarly, light sources 30 are turned off when the output signal exceeds a value. One of the functions is typically used for standard daytime operation, whereby light sources 30 are turned on when a receptacle is opened in order to illuminate the articles inside the receptacle.

The other function is used for night operation, for example, but not limited to using system 10 as a travel nightlight, which turns on when the surroundings are dark. The assignment of the first and second functions for a particular use (e. g. for day or night use) depends on the configuration of light sensor arrangement 32 and light sensor circuit 40. In particular, the assignment of functions depends on how the output signal of light sensor arrangement 32 varies with incident light and how light sensor circuit 40 processes the output signal of light sensor arrangement 32.

It will also be appreciated by those ordinarily skilled in the art that light sensor circuit 40 can be configured so that the signal sent to controller 34 is preprocessed depending on the selected mode of operation (i. e. day or night mode), so that controller 34 does not need to know whether day or night operation is required. Controller 34 includes a software loading port 42 for loading software onto controller 34. The software provides processing instructions for controller 34 to perform. The software includes an algorithm for deciding when to turn light sources 30 on or off based on the signal received by controller 34. This algorithm is described in more detail with reference to Fig. 5. A suitable controller/processor for controller 34 is the MSP430 processor commercially available from Texas Instruments Inc. of 12501 Research Blvd. , Austin, TX 78714.

Control switch 36 is electrically connected to controller 34 and/or light sensor circuit 40 depending on the chosen configuration of controller 34 and light sensor circuit 40 as described above. Control switch 36 has four settings. Two manual settings and two automatic settings. The manual settings are used to manually turn on and off light sources 30. The two automatic settings are used to select either day or night modes of operation, as described above.

Reference is also made to Fig. 5, which is a flow chart showing the steps of operation of controller 34 of system 10 of Fig. 4. As described above, controller 34 runs software for performing an algorithm to decide whether the output signal of light sensor arrangement 32 is high enough or low enough to switch light sources 30. The use of light sensors for receptacle

lighting is not generally preferred by the prior art, as the light sensors generally turn the lighting on and off based upon predetermined surrounding lighting level. For example, in bright daylight the receptacle lighting may remain on if the receptacle is not closed properly or in poor lighting conditions the receptacle lighting may not activate even when the receptacle is open. Therefore, the present invention includes controller 34 which compares the output signal of light sensor arrangement 32 to an average of previously stored output signals of light sensor arrangement 32 (and not to a predetermined lighting level) as will be described in more detail below.

Controller 34 is configured by the software to perform the following steps. First, controller 34 receives the output signal from light sensor arrangement 32 (block 44). The term"receives the output signal from light sensor arrangement 32"also includes receiving the output signal via light sensor circuit 40 after the output signal of light sensor arrangement 32 has been processed by light sensor circuit 40. Second, the output signal is stored in the temporary memory location of controller 34 (block 46). Third, the output signal is compared to one or more (typically five) previously stored output signals, typically to an average of the five previously stored output signals (block 47). Fourth, if the difference between the output signal and the previously stored output signals is greater than a certain value or proportion of the previously stored output signals, then light sources 30 are turned on or off as appropriate (block 48). In accordance with a most preferred embodiment of the present invention, light sources 30 are turned on or off in response to the output signal differing typically by 20% or more as compared to the previously stored output signals. However, it will be understood that if light sources 30 have already been turned on in response to a 20% or more difference then they will not be turned off if a subsequent reading is also 20% greater. However, light sources 30 will only be turned off if a subsequent reading is 20% lower. Therefore, the decision of whether to turn light sources 30 on or off depends upon the current status of light sources 30 (i. e. either on or off), the mode of operation as set by control switch 36 (e. g.: day or night mode) and the difference between the current output signal and the previously stored output signals. The duration of each sensor reading will typically depend on the sensor used. The inventors have found that a sensor reading duration in the range of 0.2 to 0.8 seconds, preferable 0.3 to 0.5 seconds, gives a good reading. When light sources 30 are already turned on, sensor readings are typically performed every 10 seconds.

When the sensor reading are taken, light sources 30 are turned off automatically in order to prevent false readings due to the light from light sources 30 reaching light sensor arrangement 32. In daylight mode (when light sources 30 are turned on due to a 20% increase in surrounding light), light sources 30 are automatically turned off after 30 seconds to 1 minute in order to save

battery power. If the user still wants light sources 30 to be turned on, the user operates controller 34 to manually turn on light sources 30. When light sources 30 are turned off, sensor readings are performed more often, typically every 0.5 to 1 seconds so that when the receptacle is opened there is only a short delay before light sources 30 are turned on. If light sensor arrangement 32 senses very bright light conditions, for example, but not limited to, greater than 2,700 Lux, then light sources 30 are not turned on, as the surrounding light is enough to illuminate the receptacle.

Reference is now made to Fig. 6 is an isometric view showing base 16 of system 10 of Fig. 1. System 10 includes an attachment arrangement 50 configured for reversibly attaching housing 14 to a receptacle. Attachment arrangement 50 is mechanically connected to base 16.

Attachment arrangement 50 includes a strip of hooks 52 and a strip of loops 54 for attachment to a corresponding strip of hooks and strip of loops connected to the receptacle. Strip of hooks 52 and strip of loops 54 are typically attached to base 16 using adhesive. Strip of hooks 52 and strip of loops 54 are commercially available from Velcro USA Inc. , 406 Brown Avenue Manchester, NH 03103. In this way, system 10 is reversibly attached to the receptacle. It will be appreciated by those ordinarily skilled in the art that attachment arrangement 50 can include only hooks or loops for attachment to loops and hooks of the receptacle, respectively. In accordance with an alternate embodiment of the invention, strip of hooks 52 and strip of loops 54 are replaced by magnets configured for reversibly attaching housing 14 to a metal element of the receptacle by a magnetic force between the magnet and the metal element.

Reference is now made to Fig. 7 is a cross-sectional view of a first alternate attachment arrangement 56 for use with system 10 of Fig. 1. Attachment arrangement 56 is an alternate arrangement for attaching system 10 to a receptacle. Attachment arrangement 56 includes two tapering pins 62. Attachment arrangement 56 also includes a mounting plate 58 having two holes 60 therein. Each hole 60 is configured so that part of one pin 62 fits into hole 60. Base 16 includes two openings 64 therein. Each opening 64 is configured for pressure fitting the narrow end of one pin 62 therein. Therefore, system 10 is reversibly attached to a receptacle by disposing mounting plate 58 on one side 66 of a piece 68 of the receptacle. Housing 14 is disposed on another side 70 of piece 68. Pins 62 are inserted through holes 60 of mounting plate 58. Pins 62 are then inserted into openings 64 of base 16. Pins 62 are attached to openings 64 by a pressure fit, thereby attaching base 16 to mounting plate 58 via piece 68 of the receptacle.

Reference is now made to Fig. 8, which is a cross-sectional view of a second alternate attachment arrangement 76 for use with system 10 of Fig. 1. Attachment arrangement 76 is an alternate arrangement for attaching system 10 to a receptacle. Attachment arrangement 76 is substantially the same as attachment arrangement 56 except that mounting plate 58 is replaced by a clip 78 which is attached to system 10 using pins 62. Clip 78 is typically an inwardly biased plastic or metal clip. Clip 78 is used in order to reversibly attach system 10 to a variety of surfaces, such as a pocket in a receptacle.

Reference is now made to Fig. 9 is an isometric view of system 10 of Fig. 1 attached back-to-back to another substantially same lighting system 72. Both system 10 and lighting system 72 typically include attachment arrangement 50 having strip of hooks 52 and strip of loops 54 of Fig. 6. Therefore, strip of hooks 52 of system 10 attaches to strip of loops 54 of lighting system 72. Similarly, strip of loops 54 of system 10 attaches to strip of hooks 52 of lighting system 72. In this manner, housing 14 of system 10 is reversibly mechanically connected to housing 14 of lighting system 72. Once attached together, system 10 and lighting system 72 can be attached to the receptacle using a line or cord 74. One end of line 74 is typically connected to system 10 by tying. The other end of line 74 is typically connected to the receptacle by a clip or Velcro (not shown). In this manner, it is easy to move system 10 and lighting system 72 from one compartment of the receptacle to another compartment of the receptacle as the need arises.

It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and sub-combinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art which would occur to persons skilled in the art upon reading the foregoing description.