Effective date : Year of fee payment : 4. Year of fee payment : 8. A single combination task lamp and flashlight, providing separate flood and spot light beams, independently controlled in a three-state sequence by simple push button switches.
The two kinds of light beams are produced by separate arrays of compact light emitting devices. The module is enclosed within a slim, rugged housing and easily field replaceable with minimal tools.
Field of the Invention. The present invention generally relates portable lighting apparatus and, more particularly, to optical, mechanical, and electrical features for the design, utility, and performance of portable task lighting and flash light apparatus using very small light emitting devices.
Lighting devices can be grouped into two basic applications: illumination devices and signaling devices. Illumination devices enable one to see into darkened areas. Signaling devices are designed to be seen, to convey information, in both darkened and well-lit areas.
Architectural lighting design
Widely available varieties of portable lighting apparatus, which may combine both the illumination type and the signaling type, employ a variety of lighting technologies in products such as task lamps and flashlights. Each new development in technology is followed by products that attempt to take advantage of the technology to improve performance or provide a lower cost product.
Other types of incandescent bulbs such as halogen lamps have become standard in a number of ordinary applications. High intensity discharge HID and other arc lighting technologies are finding ready markets in automotive and high brightness flood lighting, spot lighting, and signaling applications. More recently, solid state or semiconductor devices such as light emitting diodes are finding use as compact and efficient light sources in a wide variety of applications.
These applications include high intensity personal lighting, traffic and other types of signal lighting, automotive tail lamps, bicycle lighting, task lighting, flashlights, etc.
This technology is relatively new, however, and conventional products heretofore have suffered from a number of deficiencies.
For example, current products utilizing light emitting diodes as light sources tend to be highly specialized and suited to only a single use, thus limiting their versatility as lighting devices or instruments for more ordinary uses. Further, such specialized devices tend to be expensive because of the relatively low production volumes associated with specialized applications.
Moreover, there exist certain lighting applications for which conventional light sources are unsatisfactory because of limitations in brightness, operating life, durability, power requirements, excessive physical size, poor energy efficiency, and the like.
Newer light sources such as semiconductor light emitting diodes are very small, very durable, use relatively little power, have long lifetimes, and emit very bright light relative to the electrical power input. While some presently available products employ these semiconductor light sources, their full potential is frequently not realized.
This may occur because of deficiencies in optical components and drive circuits, or interface components having particular combinations of structure and function are not available.
Another factor may be that improvements in the design and configuration of multiple, small, high intensity light sources for maximum illumination efficiency and convenience of use have not been forthcoming.
An advance in the state of the art could be realized if such small, high intensity and high efficiency light emitting devices could be adapted to more general and more versatile lighting applications such as flood lighting or spot lighting.
Such advances could occur if improvements in the components, circuits, and product architecture are developed and provided. For example, in the field of lighting devices used by security personnel, there is a need for high intensity illumination in a battery powered, hand-held instrument that is very rugged, efficient in the use of power, and that provides a beam of light designed to illuminate dark regions of or indistinct objects within an area being patrolled or investigated.
Many circumstances require a bright, well-shaped flood light beam for illuminating relatively large areas. Other situations require a more directed beam of light, to spotlight particular areas or objects. Ideally, both modes of illumination would be combined in a single instrument.
In another aspect of the invention, there is provided a lens for a light emitting device LED comprising a combination of an aspherical reflecting surface and a spherical refracting surface.
The aspherical reflecting surface has a focal point and a central axis of symmetry—i. The spherical refracting surface is disposed in the path of the reflected light rays, centered on and normal to the central axis, concave in the forward direction of the reflected light rays and joins the aspherical reflecting surface at a boundary equidistant from the optical axis.
The spherical refracting surface includes a plurality of N concentric annular surfaces, each annular surface having a cross section convex in the forward direction and disposed substantially at uniform radial intervals between the optical axis and the junction with the aspherical reflecting surface.
US20070159816A1 - Combination task lamp and flash light - Google Patents
In another aspect of the invention, there is provided a light emitting module comprising a frame configured as a heat sink having first and second opposite sides and a forward axis normal to the first side thereof.
Each one of an array of a plurality N of light emitting assemblies LEAs connected to a source of current is mounted on the first side of the frame configured as a heat sink such that the central axis of light emission of each LEA is disposed at a non-zero first predetermined angle relative to the forward axis. The frame may include a printed circuit embodying an electric circuit coupled to the array of light emitting assemblies.
In yet another aspect of the present invention, there is provided an electric circuit comprising an electric circuit having an output and a single pole, single throw SPST switch having normally open NO first and second contacts and a latching mechanism operable by an actuating member. The switch is connected in the electric circuit for activating at least a conducting path in the electric circuit wherein the switch is sequentially operable in first, second, and third states corresponding respectively to latched engagement, momentary disengagement, and latched disengagement of the first and second contacts in the switch.
Compact fluorescent lamp working principle with circuit pdf merge
The first state provides activation of the electric circuit in an OFF condition, the second state provides momentary activation of the electric circuit in an ON condition, and the third state provides latched activation of the electric circuit in an ON condition.
In yet another aspect of the present invention, there is provided a method of operating a single pole, single throw SPST switch in three distinct states in an electric circuit.
A repeated exertion of the second force upon the actuating member of the SPST switch causes engagement of the first and second contacts, causing in turn the electric circuit to enter the OFF condition. The foregoing aspects and other objects of the invention disclosed herein will be understood from the following detailed description read with reference to the accompanying drawings of one embodiment of the invention.
Structures appearing in more than one figure and bearing the same reference number are to be construed as the same structure.
Referring to FIG. The PLD 10 includes an elongated tubular housing 12 defined along a longitudinal axis 14 , having a first section 16 at a first end for containing a plurality of light emitting assemblies or light sources 22 , and further having a second section 18 at a second end for containing a power supply See FIG.
Visible through a clear side lens 24 in FIG. The side lens 24 is an internal component of the housing 12 as will be further described with FIG. The row of four light sources 22 may be denoted as a first directed array of light sources Any number of individual light sources 22 may be arranged in a variety of configurations to form a directed array.
In the present illustrative embodiment, the configuration of four light sources 22 disposed in a row is selected to illustrate the principles of the invention in a specific product application. In general, each of the light sources 22 may be a combination of a light emitting device LED and a lens assembly.
An LED may be a semiconductor light emitting diode or it may be a light emitting device employing a different technology to produce light. A lens assembly may be a single, solid body of optical material having one or more predetermined optically responsive surface configurations or it may be constructed as a combination of separate, predetermined optical elements assembled into a single unit.
In the illustrated embodiment, the lens is a solid body element having a plurality of predetermined surface configurations that is designed for use with certain types of light emitting diodes.
Continuing with FIG.
Although the clear top lens 28 indicates that a single light source is shown in the illustrative embodiment, it is possible that several individual light sources may be used to construct the second directed light array The second directed light array 26 visible through the clear top lens 28 may be configured as a spot light beam or as a flood light beam.
Typically, with a PLD 10 having a first directed light array 22 configured to provide a flood light beam, the second directed light array 26 may be advantageously configured as a spot light beam. As will become apparent, when using very small or compact light sources, the type of light beam provided is largely dependent upon the lens assembly provided for the light source. Generally, the light source for the second directed light array 26 may be aligned such that its optical axis is coincident with or aligned parallel with the longitudinal axis In other applications, the alignment of the second directed array 26 may be disposed at an angle fixed or adjustable relative to the longitudinal axis.
In such cases, the optical axis of the second directed light array 26 would be aligned at a non-zero angle with respect to the longitudinal axis.
WORKING OF CFL
At the end of the first section 16 of the elongated housing 12 a lens frame 30 disposed over the second directed light array of lens 26 is provided to protect the clear top lens The lens frame 30 may be formed as part of the elongated housing 12 or implemented as a separate component.
It will be observed that the lens frame 30 has a three-sided, tubular shape, i.
This triangular shape mimics the shape of the cross section of the elongated housing 12 in the first section In the illustrated embodiment, the triangular cross section of the first section 16 may be configured to merge with a substantially round or oval cross section of the second section The triangular shape is provided so that when the PLD 10 is placed on a horizontal surface, the PLD 10 naturally assumes an orientation so that the flood light beam from the first directed light array is projected upward at an angle from the horizontal.
This is a useful feature when both hands must be free to work. At the opposite end of the elongated housing 12 , the second section 18 may be configured to contain a power supply such as a battery pack. The external portions of the second section 18 may be formed as a handle or with other features to provide a comfortable or a non-slippery gripping surface.
A removable end cap 32 may be provided for access to the interior of the second section 18 of the elongated housing 12 such as to replace a battery. In other applications the cap 32 may include a connector for a line cord not shown in FIG. As will be described further with FIGS. In FIG.
BACKGROUND OF THE INVENTION
The light emitting assembly including the light emitter and the lens assembly share the same optical axis. In the example illustrated in FIG. Each of the light emitters E 1 , E 2 , E 3 , and E 4 are shown mounted on the plane surface 48 in the interior of the elongated housing The light sources 22 , associated with each of the light emitters are not fully illustrated so that the relationship of the light emitters E 1 , E 2 , E 3 , and E 4 and the elongated housing 12 may be more clearly illustrated.
In the illustrated embodiment, a light emitter may be a light emitting diode having an active element See also FIG. The base 42 may be attached to a substrate 44 , such as a printed circuit board.
The substrate 44 may be a laminated structure that includes a bottom layer not shown of thermally conductive material such as aluminum. The aluminum layer provides an integral heat sink for the light source emitter assembly for low power applications and a suitable conductive bonding surface for higher power applications where more heat must be dissipated via an external heat sink in contact with the substrate In the illustrated example, the plane surface 48 is preferably configured as such external heat sink for conducting heat away from the light emitting assembly and dissipating it into the surroundings.
A thermal compound of the type well known in the art may be placed in the interface between the substrate 44 and the plane surface As described previously, an optical axis is defined for each of the light sources Further, the individual planes containing the reference line and the optical axis of each light emitting assembly are disposed at substantially equal angles from each other, in the manner of spokes of a wheel when viewed from a point on the forward axis looking back toward the origin of the forward axis.
This arrangement of the optical axes of the individual light emitting assemblies is shown in FIG. The relationship may be stated as the ratio of the divergence angle to the beam width angle.
Thus, for a given beam width from a light emitting assembly having a substantially point source light emitter and a lens assembly configured to produce the given beam width, the optimum amount of divergence between two such light emitting assemblies or pairs of such light emitting assemblies turns out to be one quarter of the beam width of the individual light emitting assemblies.
This index is very useful in devising arrays of light emitting assemblies to provide a particular composite beam of light or illumination pattern from the array, as will become more apparent in the detailed description which follows. Continuing with the description of FIG. In the illustrated embodiment, the light sources are disposed in a row because of the space limitations of the elongated tubular housing However, in an embodiment that allowed the four light sources to be clustered close together on a flat plane surface in a rectangular array, for example at the four corners of a square, the normal lines may be closer together and, in fact, a single normal line placed at the center of the array could serve as the reference for all four of the light sources.
Further, each of the four light sources would also be divergent in a direction that is at right angles from the direction of divergence of each of its neighboring light source. The same aiming arrangement is provided in the illustrated embodiment of FIG.
That is, the optical axes of the light sources 22 diverge in the compass directions N, W, S, and E, when viewed from the position of the longitudinal axis 14 , even though the light sources 22 are arranged in a single row and are somewhat more widely spaced.