Patent Application
20170299166
The present invention pertains to illumination devices and, more particularly, to hand held illumination devices more commonly referred to as flashlights.
Flashlight have ubiquitous applications for providing transportable illumination, both at night and during the day in spaces subject to little or no lighting. Such venues may include the basement or attic of a home or some form of industrial site such as a factory or underground work site. A wide variety of professionals and workers require use of a flashlight during their regular work day as they move from adequately illuminated settings to darker settings where additional illumination is required. Examples include, among others, professional inspectors such as home inspectors and civil engineers inspecting a work site. Conventional flashlights typically possess a simple on/off switch, which must first be switched on when moving from an adequately illuminated setting to one that is inadequately illuminated, and then must be switched “off” when moving back into an adequately illuminated setting. While it's not absolutely essential to switch the flashlight back off again, battery life suffers if the flashlight is not switched off when additional illumination is no longer required. In a number of instances the flashlight user, such as a professional inspector may inadvertently forget to deactivate their flashlight in the excitement of what they have discovered in the inadequately illuminated inspection site. Sometimes, seemingly frequently, this forgetfulness results in the flashlight being irritatingly inoperative until the batteries are replaced.
Thus, there still exists a need for a flashlight that doesn't have to be turned on and off as a user moves from adequately to inadequately illuminated venues but which still preserves battery life over simply leaving the flashlight on.
Flashlights are also almost invariably the first go-to item during a power failure occurring at night or in venues having little or no natural illumination, such as windowless settings. One problem persists in such settings, finding the flashlight when a venue is reduced to inadequate illumination or total darkness due to the power failure. Emergency devices do exist to address this problem, but such flashlights require connection to the existing power grid in order to monitor the status of the power grid and activate the flashlight in the event of a power failure. This connection requirement limits the available placement of the flashlight to locations capable of providing this connection. One such device, for example, must be plugged into an electrical wall socket. Thus, there still exists a need for a flashlight that can be found when a venue is suddenly plunged into darkness during a power failure but which does not also require connection to the power grid or a wall socket.
The present invention provides a flashlight overcoming the above mentioned deficiencies by providing hands free automatic activation and deactivation based upon ambient light conditions. The present invention allows users to move from adequately illuminated to inadequately illuminated settings and back again without having to manually activate the flashlight, thereby saving battery power and avoiding annoyance in many work settings. The flashlight of the present invention will also self-activate when in an ambient light sensing mode if the venue in which the flashlight resides is suddenly plunged into inadequate illumination or effectively total darkness. In one embodiment the flashlight of the present invention further includes a low-powered secondary light source that is activated when the present invention is in an ambient light sensing mode. This secondary source provides an easy means of determining when the flashlight of the present invention is operating in an ambient light sensing mode and further facilitates users finding this inventive flashlight in dark or pitch black setting resulting from a power failure.
To attain these goals and advantages the present invention generally comprises a flashlight including a flashlight body, a light source directing a light output from one end of the flashlight body, a power source, an ambient light sensor responsive to ambient light conditions and a control circuit electrically connected to the ambient light sensor and the light source that is configured to enable control of the output of the light source in response to ambient light conditions.
In one preferred embodiment the control circuit enables the ambient light sensor to regulate the light output of the light source in proportion to the amount of ambient light, wherein the light source provides proportionally more light output as ambient light decreases. In another embodiment the flashlight body defines a rim at a forward light bearing end of the flashlight and the ambient light sensor is mounted on this rim. In yet another embodiment the rim of the flashlight body forms at least one depression and the ambient light sensor is mounted in this depression. In a further embodiment of the present invention the flashlight of the present invention includes an off/on switch and the control circuit is configured to be responsive to operation of said switch to energize the light source and enable control of its output in response to ambient light conditions in a first mode and deactivate the light source in a second mode. In still another embodiment of the present invention the control circuit includes a third mode of operation, responsive to the operation of said switch, in which the light source is activated at a constant output nonresponsive to ambient light conditions. Yet a further embodiment of the present invention includes a secondary light source mounted on the flashlight to indicate when the control circuit is operating in the first mode.
The foregoing, and further advantages, features and principles of the present invention will become more readily apparent from the following detailed description of several preferred embodiments of the present invention that follows below with reference to the accompanying drawings.
Referring to the figures, and more particularly
In one preferred embodiment the flashlight body 10 has a first diameter portion 24 having a diameter configured to comfortably fit within most user's hands and a second diameter portion 25 having a second diameter designed to accommodate a reflector 68 (see
In accordance with one aspect of the present invention, an ambient light sensor 29 is mounted on the body of the flashlight body 10. In one preferred embodiment this ambient light sensor 29 is mounted in one of the depressions 18 in the rim 15 of the flashlight. While it is within the spirit and scope of the present invention to mount the ambient light sensor 29 at other locations on the flashlight body 10, such as for example the end cap assembly 23, the inventors have determined the most effective location for placement of the ambient light sensor 29 is on the forward rim 15 of the flashlight body 10. By configuring the depressions 18 as described above, communicating with an edge of the flashlight body 10 generally perpendicular to the rim 15, and by mounting the ambient light sensor 29 within the depression 18 the ambient light sensor is able to respond to ambient light levels about the flashlight even when the flashlight body 10 is placed with the rim 15 face down on a flat surface, such as a desk or table, and in direct contact therewith.
In one embodiment of the present invention a control circuit 30 (see
When the flashlight body 10 is placed in a first ambient light sensing mode and located in an ambient light environment having sufficient illumination the ambient light sensor 29 will sense this level of illumination and the light source 33 will not activate. If, however, while in this mode of operation the flashlight is moved to another location having inadequate lighting, then the ambient light sensor 29 will sense the reduction in ambient light and the light source 33 will activate without requiring further user input. Further, if the flashlight is removed from the location having inadequate ambient lighting into one having adequate illumination, then the ambient light sensor 29 will again sense the increase in illumination and the light source 33 will be deactivate without user input. Thus, in this mode of operation users of the present inventive flashlight may move from adequately illuminated settings to inadequately illuminated settings and back again with the flashlight effectively activating and deactivating the light source 33 without user input. Normally the light source 33 is the most power consumptive element of the flashlight, thus in accordance with the present invention power consumption may be regulated without user input, but instead based upon ambient lighting conditions as detected by the ambient light sensor 28.
Alternative to moving the flashlight from adequately illuminated to inadequately illuminated settings, if the flashlight body 10 is in an ambient light environment having sufficient illumination such that the light source 33 is not active and if the ambient light environment becomes less illuminated, resulting for example from a power failure, then the ambient light sensor 29 will again detect this decrease in illumination and again the light source 33 will be activated without user input. This mode of operation facilitates the flashlight automatically providing illumination during a power failure without user input, and a capability of doing so without requiring the flashlight to be plugged into or otherwise electrically connected to a wall socket or the power grid.
In one preferred embodiment the switch 20 is provided with a secondary light source 36 (see
Of course, it is with the spirit and scope of the present invention to include additional modes of operation for the flashlight of the present invention. For example, in one embodiment of the present invention the control circuit 30 may be configured to count the number of times a user depresses the switch 20 within a predetermined period of time to afford additional modes of operation. One such mode of operation may be a “high” beam output from light source 33 which is “always on” that is, not responsive to the level of illumination detected by the ambient light sensor 29. A further mode of operation, also activated by an additional depression of the switch 20, may be a “low” beam output from light source 33 which is also “always on” irrespective of the level of ambient illumination detected by the ambient light sensor 29. This “low” beam output, while providing reduced lighting compared to the “high” beam output, also consumes less power and thus prolongs battery life compared to the “high” beam rate of consumption.
In accordance with yet another preferred embodiment of the flashlight of the present invention may further be provided with an additional light source 38 in the end cap assembly 23 as shown in
As shown in
As is also known in the flashlight art, user operated switch 20 and the secondary light source 36 may comprise a unitary structure configured to fit within the counter-sunk bore 22 in the flashlight body 10. This unitary structure, including secondary light source 36, may be mounted on a frame 76 configured to fit within the flashlight body 10. A flexible and translucent cover 78 may also be provided to cover the unitary structure including the switch 20 and secondary light source 36 so as to afford a water resistant seal over this unitary structure. This cover 78 may be either pressed or biased against an inner surface of the flashlight body 10 by the frame 76 or, alternatively, bonded to the flashlight body 10.
A control circuit for controlling operation of the flashlight of the current invention in one preferred embodiment is shown if
As also illustrated in
A separate electrical path for light source 33 is afforded through a solid state tri-state switch 126. This tri-state switch 126 has a source 128 connected to the light source 33 and a drain 130 connected to ground. This configuration affords a current path from the power input 80 through the light source 33 to ground through switch 126 that is separate from the current path through switch 110. The gate 133 of tri-state switch 126 is connected via resistor 136 to a further output 138 of the control chip 86. A resistor 140 further bridges the drain 130 and gate 133 of tri-state switch 126 in series with resistor 136 as is generally well known in the electronics arts.
In operation, the control chip 86 regulates operation of the light source 33 in response to the number of times a user activates switch 20. The control chip 86 may activate either switch 110 or, alternatively, activate tri-state switch 126 to provide a completed conductive path from the power input 80 to ground through the light source 33. High and low output beams for the flashlight of the present invention are provided by control chip 86 deactivating switch 110 and activating tri-state switch 126 in either of a first or second conductive state. Tri-state switches are also well known in the electronics arts.
When the flashlight of the present invention is to operate in a light sensing mode, tri-state switch 126 is deactivated and switch 110 is activated. In one preferred embodiment of the present invention, activation of switch 110 is achieved by control chip 86 providing a “high” or positive voltage signal to gate 118 of solid state switch 110. In this embodiment the flashlight of the present invention is then responsive to ambient light conditions by ambient light sensor 29 becoming more conductive in response to increasing levels of ambient illumination, thus grounding the gate 118 of the solid switch 110 and rendering the switch 110 non-conductive. As mentioned above the conductance of switch 110 may be made to vary in relation to the ratio of charge applied between the drain 116 and gate 118 of switch 110. By employing a photoresistor as the ambient light sensor 29, the conductivity of switch 110 may then be efficaciously made to vary proportionally with the magnitude of illumination detected by the photoresistor-type ambient light sensor 29. In this configuration as the resistance of the photoresistor-type ambient light sensor varies, so to does the voltage ratio between the gage 118 and drain 116 of the switch 110 proportionally vary. As a consequence thereof the light source 33 can be made to provide proportionally more output as the magnitude of ambient light decreases and to provide proportionally less light output as the magnitude of ambient light increases until the photoresistor-type ambient light sensor 29 effectively grounds gate 118 of switch 110, rendering switch 110 non-conductive and effectively turning the flashlight of the present invention “off” without further user input.
Having described and illustrated the present invention in various preferred embodiments, it should be readily apparent to those skilled in the relevant arts that the present invention can be modified in arrangement and detail to provide numerous other embodiments that do not depart from the spirit and scope of this invention. For example, the tri-state switch 126 could be replaced with two separate bi-state switches connected in parallel to light source 33 without departing from the scope of the present invention. Alternatively, the flashlight of the present invention could simply be provided with a single output mode nonresponsive to ambient light conditions, in which instance tri-state switch could be replaced with a simple bi-state type solid state switch. Accordingly, all equivalent relationships to those illustrated in the drawings and described in the specification above are intended to be encompassed within the scope of the present invention, s set forth in the claims below and equivalents thereof.
It is to be further understood that the phraseology and terminology employed herein are for the purposes of description only and should not be regarded as limiting the scope of the present invention. Therefore, the foregoing description of the present invention is to be considered as illustrative only of the principles of the present invention. Further, since numerous modifications, changes and alternative embodiments will occur to those skilled in the art, the present invention is not to be limited to the structures, elements, construction and operation shown and described above, but solely by the claims set forth below and equivalents thereof.
