Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V23/00—Arrangement of electric circuit elements in or on lighting devices
  • F21V23/04—Arrangement of electric circuit elements in or on lighting devices the elements being switches
  • F21V23/0414—Arrangement of electric circuit elements in or on lighting devices the elements being switches specially adapted to be used with portable lighting devices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21L—LIGHTING DEVICES OR SYSTEMS THEREOF, BEING PORTABLE OR SPECIALLY ADAPTED FOR TRANSPORTATION
  • F21L4/00—Electric lighting devices with self-contained electric batteries or cells
  • F21L4/02—Electric lighting devices with self-contained electric batteries or cells characterised by the provision of two or more light sources
  • F21L4/022—Pocket lamps
  • F21L4/027—Pocket lamps the light sources being a LED
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V5/00—Refractors for light sources
  • F21V5/006—Refractors for light sources applied to portable lighting devices
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B3/00—Simple or compound lenses
  • G02B3/10—Bifocal lenses; Multifocal lenses

Definitions

• the present disclosure relates to dual-focus portable lighting devices, such a flashlights that emit beams having different focal distances and/or beam widths.
• Flashlights have been produced that allow adjustment of the light beam in a continuous range of beam widths and/or focal distances ranging from a flood beam to a narrow beam, and vice versa.
• such systems typically compromise either the light output of the flood beam or the narrow focus (e.g., beam distance) of the spot beam.
• the brightness of the flood light may be compromised in order to achieve a long beam distance with the spot beam, or the beam distance of the spot beam may be compromised in order to achieve more light output in the flood mode, or both.
• Figure 1 illustrates a front perspective view of a dual-focus flashlight, wherein the flashlight has a single lens having two separate focusing elements disposed therein, each focusing element offset a short distance from the center of the lens;
• Figure 2 illustrates a partial cutaway view of the dual-focus flashlight of Figure 1 , showing a partial cross sectional view through each of the two focusing elements, and showing two LED light sources having two different intensities, wherein one of the two LEDs is positioned behind each focusing element, and wherein each LED is mounted a different distance from its respective focusing element;
• Figures 3A and 3B show a perspective view (Figure 3A) and a cross-sectional view (Figure 3B) of the lens of the dual-focus flashlight of Figure 1 , illustrating the two focusing elements, each of which is spaced slightly away from the center of the lens;
• Figures 4A and 4B an exploded view ( Figure 4A) and a perspective view ( Figure 4B) of the lens and base member of the dual-focus flashlight of
• Figure 1 illustrating the two focusing elements and a base member with two LED light sources mounted thereto;
• Figure 5A and 5B are two cross sectional views of the lens, base member, and LEDs of Figure 4, showing the light distribution from the flood focusing element/LED (Figure 5A) and the spot focusing element/LED ( Figure 5B); and
• FIGS. 6A and 6B are perspective views of a flashlight having a lens with three focusing elements, and a lens with four focusing elements, all in accordance with various embodiments.
• Coupled may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other.
• a phrase in the form "A/B” or in the form “A and/or B” means (A), (B), or (A and B).
• a phrase in the form "at least one of A, B, and C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).
• a phrase in the form "(A)B” means (B) or (AB) that is, A is an optional element.
• Embodiments herein provide an optical system that allows for a portable lighting device, such as a flashlight, that optimizes the light output and beam focus of both a flood beam and a spot beam.
• a portable lighting device such as a flashlight
• these lighting systems have various limitations. Some flashlights seek to optimize light output (e.g., lumens) of the flood beam at the expense of beam distance in the spot beam configuration.
• Other flashlights seek to optimize beam distance in the spot position, but sacrifice light output in the flood position. Still others compromise both beam distance and light output in an effort to split the difference between producing an optimal flood light and an optimal spot light.
• various embodiments of the lighting systems disclosed herein include a single lens having two separate focusing elements disposed therein, one for a flood beam and one for a spot beam.
• each of the two focusing elements is spaced a small distance from the center of the lens, and each is positioned in front of one of two light sources, such as LEDs.
• the flood beam focusing element and the spot beam focusing element are each designed to perform a single function (e.g., either spot or flood beam focusing).
• the flood beam focusing element may be optimized to shape the light beam into a wide, consistent flood beam, which, in various embodiments, may provide bright illumination over a wide area.
• the spot beam focusing element may be optimized to focus the light beam into a narrow, bright beam, which, in various embodiments, may travel a great distance.
• the size of each light source also may be optimized to perform optimally under the selected condition (e.g., flood beam or spot beam).
• the LED that pairs with the flood beam focusing element e.g., the flood beam LED
• the flood beam LED may have a larger size "die" or light- emitting surface compared to the spot beam LED, and in some embodiments it may have a wider viewing angle of light output and/or may emit more lumens than the spot beam LED.
• using an LED with a larger die helps produce a wider, brighter light that is more easily dispersed into a wide, bright beam.
• the LED that pairs with the spot beam focusing element may have a smaller size "die” or light-emitting surface (compared to the flood beam LED), and it may have a narrower viewing angle of light output and/or may emit fewer lumens than the flood beam LED.
• using an LED with a smaller viewing angle for the spot beam may be helpful because the light leaves the LED in a tighter beam, thereby making it easier to shape into an even tighter beam as it passes through the focusing element.
• a smaller “spot beam” LED may emit less light than a larger “flood beam” LED, but the tighter viewing angle means the light will be more intense and “packed” into a smaller beam.
• a "tight" spot beam may travel further than a large, spread-out flood beam from the brighter and larger "flood beam” LED.
• each LED may be disposed on a base member that, when installed in the flashlight, positions the larger "flood beam” LED a short distance from the "flood beam” focusing element, and the smaller “spot beam” LED a greater distance from the "spot beam” focusing element.
• positioning the "spot beam” LED farther back from the focusing element may allow the "spot beam” focusing element to shape the spot beam into a tight beam.
• positioning the "flood beam” LED a smaller distance from the focusing element may allow the "flood beam” focusing element to disperse the flood beam over a larger area.
• a dual-focus flashlight that overcomes the shortcomings of prior art devices.
• one LED In a conventional single- LED focusing flashlight, one LED must serve as the light source for both the spot beam and the flood beam.
• the resulting spot beam In a flashlight having an LED with a small die, a tight viewing angle, and a lower total light output, the resulting spot beam would be bright, tight, and travel a long distance, but the width and total light output of the flood beam would be sacrificed.
• the flood beam would large and the total lumen rating would be high, but the spot beam would travel a shorter distance, would be wider in size, and would not be as suitable for long distance use.
• the dual-focus flashlights disclosed herein overcome these issues, and may produce both an optimal spot beam and an optimal flood beam.
• the dual-focus flashlights described herein do not include any focus adjustment mechanisms, as the distance between each light source and its focusing element is fixed. Accordingly, in various embodiments, the disclosed flashlights may have few or no moving parts, and as a result, they may be lighter and/or more durable than existing focusing flashlights. Additionally, in various embodiments, a user may toggle between the flood setting, the spot setting, and/or a dual setting wherein both LEDs are lit with the push of a single button or switch, for instance which may be located in any convenient position on the housing, such as the end or a side of the flashlight.
• a user may turn the flashlight on and cycle between “spot” and “flood” modes (or “spot,” “flood,” and “dual source” modes) with repeated activations of a single push button.
• buttons or other control elements may be provided for "power,” “spot,” “flood,” and, optionally, “dual source” (e.g., both spot and flood LEDs powered on
• FIG. 1 illustrates a front perspective view of a dual-focus flashlight, wherein the flashlight has a single lens having two separate focusing elements disposed therein, each focusing element offset a short distance from the center of the lens, in accordance with various embodiments.
• the flashlight 100 may have a traditional or conventional elongated housing 102 with a single lens 104 at one end.
• lens 104 may include two separate focusing elements, 106a, 106b, for shaping a light beam into a spot beam with a spot beam focusing element 106a, or for shaping a light beam into a flood beam with a flood beam focusing element 106b.
• lens 104 is illustrated as round, one of skill in the art will appreciate that it may take other forms, such as a quadrilateral, oval, or crescent.
• both of the spot focusing element 106a and the flood focusing element 106b may be spaced slightly away from the center point of lens 104.
• the illustrated embodiment shows the two focusing elements 106a, 106b as being spaced slightly different distances from the geometric center point of lens 104, in other embodiments they may be spaced approximately the same distance from the geometric center point of lens 104.
• the two focusing elements 106a, 106b are illustrated as being different sizes, in other embodiments they may have substantially similar diameters.
• Figure 2 illustrates a partial cutaway view of the dual-focus flashlight of Figure 1 , in accordance with various embodiments.
• a partial cross sectional view can be seen through each of the two focusing elements 106a, 106b, and two LED light sources 110a, 1 10b each having a different intensity, are positioned directly behind the lens 104.
• the spot beam LED 110a may be centered behind the spot beam focusing element 106a
• the flood beam LED 110b may be centered behind the flood beam focusing element 106b.
• the spot beam LED 110a may have a smaller die and a narrower viewing angle compared to the flood beam LED 110b, which may have a correspondingly larger die and a wider viewing angle.
• these differences in size, viewing angle, and brightness may work in concert with the different focusing elements 106a, 106b to produce a tight spot beam with a long beam distance and a bright and wide flood beam.
• the two LEDs 110a, 1 10b may be mounted to a base member 108, which may include two pedestals 112a, 1 12b configured to position each of the two LEDs 110a, 110b the optimal focusing distance behind each focusing element 106a, 106b to create an optimal spot beam and an optimal flood beam.
• the distance between the spot beam focusing element 106a and the spot beam LED 110a is greater than the distance between the flood beam focusing element 106b and the flood beam LED 110b.
• this difference in spacing may be due, at least in part, to the different optics of the spot beam focusing element 106a and the flood beam focusing element 106b.
• Figures 3A and 3B show a perspective view (Figure 3A) and a cross-sectional view ( Figure 3B) of the lens of the dual-focus flashlight of Figure 1 , illustrating the two focusing elements, each of which is spaced slightly away from the center of the lens, in accordance with various embodiments.
• lens 104 includes two focusing elements 106a, 106b, and in various embodiments, the flood beam focusing element 106b may include a plano-convex, bi-convex, convex-concave, or meniscus lens adapted to disperse the light in a wide beam.
• the flood beam focusing element 106b is illustrated as being generally round, in some embodiments, the flood beam focusing element 106b may have an oval or elongated shape.
• the light beam may be advantageous to shape the light beam to extend out to the sides of a user's peripheral vision, rather than waste light by sending it upwards, where illumination is not needed.
• an oval beam may be closer in shape to a human being's natural field of vision than a conventional round beam.
• the spot beam focusing element 106a may be a more complex lens having a central focusing element 1 14 and an annular ring portion 116 that work in concert to focus the light into a narrow, tight beam.
• the central focusing element 114 may be a plano-convex, bi-convex, convex-concave, or meniscus lens.
• either or both of the spot beam focusing element 106a and the flood beam focusing element 106b may include a rear void 118a, 118b, which may be adapted for receiving at least a portion of the LED and/or pedestal.
• the spot beam may use internal reflection to "collect" light and reflect it forward. For example, light rays may pass through the central focusing element, and then may be reflected forward in a narrow, focused beam by the internal or external sidewalls of the annular portion of the lens. This feature is best illustrated in Figure 5B, which is discussed in greater detail below.
• Figures 4A and 4B show an exploded view ( Figure 4A) and a perspective view ( Figure 4B) of the lens of the dual-focus flashlight of Figure 1 , illustrating the two focusing elements, and a base member with two LED light sources mounted thereto, in accordance with various embodiments.
• the lens 104 may include rear voids 118a, 118b, which may be adapted for receiving at least a portion of the LEDs 110a, 110b and/or pedestals 112a, 112b.
• Figure 5A and 5B are two cross sectional views of the lens, base member, and LEDs of Figure 4, showing the light distribution from the flood focusing element/LED (Figure 5A) and the spot focusing element/LED ( Figure 5B), in accordance with various embodiments.
• Figure 5A as light passes from the flood beam LED 110b through the flood beam focusing element 106b of lens 104, the flood beam focusing element 106b directs the light into a wide, bright flood beam 120b.
• the central focusing element 114 and the annular ring portion 116 of the spot beam focusing element 106a work in concert to direct the light into a tight, narrow spot beam 120a.
• the annular ring portion may reflect light in a forward direction from the inner side wall 116a of the annular ring portion 116, whereas in other embodiments, the annular ring portion may reflect light in a forward direction from the outer side wall 116b, or both.
• both the spot beam LED and the flood beam LED may be illuminated simultaneously.
• the lens 104 may include three ( Figure 6A) or four ( Figure 6B) separate focusing elements, 106a, 106b, 106c, and 106d, for shaping a light beam into a spot beam with a spot beam focusing element 106a, for shaping a light beam into a flood beam with a flood beam focusing element 106b, and additional focusing elements for shaping a light beam from third (and optionally fourth or more) light sources.
• focusing elements 106c and 106d are illustrated as flood beam focusing elements, one of skill in the art will appreciate that additional spot beam focusing elements, or even simple reflectors, may be substituted.
• the additional light sources may be colored LEDS, such as red, blue, green, or UV LEDs, or they may be infrared LEDs.
• an infrared LED may be used in conjunction with night vision goggles.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Arrangement Of Elements, Cooling, Sealing, Or The Like Of Lighting Devices (AREA)
• Non-Portable Lighting Devices Or Systems Thereof (AREA)

Priority Applications (6)

Applications Claiming Priority (4)

Publications (1)

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Family Applications (1)

Country Status (8)

Cited By (3)

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Citations (5)

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• 2015
  • 2015-07-30 CN CN201580053316.XA patent/CN106796021A/zh active Pending
  • 2015-07-30 DE DE202015009650.6U patent/DE202015009650U1/de not_active Expired - Lifetime
  • 2015-07-30 DK DK15827633.7T patent/DK3175172T3/en active
  • 2015-07-30 WO PCT/US2015/042946 patent/WO2016019162A1/en not_active Ceased
  • 2015-07-30 JP JP2017505543A patent/JP6676616B2/ja active Active
  • 2015-07-30 ES ES15827633T patent/ES2704913T3/es active Active
  • 2015-07-30 AU AU2015296238A patent/AU2015296238A1/en not_active Abandoned
  • 2015-07-30 EP EP15827633.7A patent/EP3175172B1/en active Active

Patent Citations (5)

Non-Patent Citations (1)

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