Led flashlight with lens

[0002] The present invention relates generally to illumination devices. It finds particular application in conjunction with illumination devices employing multiple light emitting diodes (“LEDs”) and will be described with particular reference thereto. It will be appreciated, however, that the invention is also amenable to other like applications.

[0003] In the field of illumination devices, there has long been a trade-off between brightness and power conservation. It is known that the use of light emitting diodes (LEDs) consume substantially less power than incandescent light bulbs. However, typically, the radiant power of LEDs has been limited so that they have been used for primarily short-range applications such as panel indicators or indoor signs. LEDs have proven useful when their size has not been a significant factor because they are viewed from small distances. Unfortunately, use of LEDs in applications such as flashlights has been limited due to inefficient means for directing available light to desired target areas. Even with the advent of high-powered LEDs, large clusters of LEDs are required to achieve adequate target-size definition. Unfortunately, these clusters are relatively expensive and consume a considerable amount of power.

[0004] The present invention provides a new and improved apparatus and method which overcomes the above-referenced problems and others.

[0005] A light emitting device includes a light emitting diode, an individual reflector well in which the light emitting diode is seated, and an individual lens over an opening of the reflector. Light produced by the light emitting diode is reflected by the reflector and focussed by the lens toward a target area.

[0006] In accordance with one aspect of the invention, the reflector is coupled to the lens.

[0007] In accordance with a more limited aspect of the invention, the light emitting device is mounted on a printed circuit board.

[0008] In accordance with another aspect of the invention, the lens provides direct light refraction to the light emitting diode.

[0009] In accordance with another aspect of the invention, the lens is one of a multiple refractive and a refractive/diffractive hybrid lens.

[0010] In accordance with another aspect of the invention, a second light emitting diode is seated in a second individual reflector well. A second individual lens is over an opening of the second reflector. Light produced by the second light emitting diode is reflected by the second reflector and focussed by the second lens toward the target area.

[0011] In accordance with a more limited aspect of the invention, the lenses are matrixed.

[0012] One advantage of the present invention is that it efficiently directs light from a semiconductor light source to a target area.

[0013] Another advantage of the present invention is that it creates a uniform, bright beam pattern for an illumination device utilizing a semiconductor light source.

[0014] Still further advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiments.

[0015] The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating a preferred embodiment and are not to be construed as limiting the invention.

[0016] FIG. 1 illustrates a cross-sectional view of an LED flashlight according to the present invention; and

[0017] FIG. 2 illustrates a top view of the light source assembly shown in FIG. 1.

[0018] With reference to FIGS. 1 and 2, an illumination device 10, or light emitting device (e.g., a flashlight), includes a housing 12 and a light source assembly 14. The housing 12 includes an open end 16 and a closed end 18. The light source assembly 14 is mechanically secured to the housing 12. Preferably, mating threads engage the light source assembly 14 to the housing 12. However, other means (e.g., a snap fit) for securing the light source assembly 14 to the housing 12 are also contemplated.

[0019] An electrical power source 24 is included in the housing. Preferably, the power source 20 includes batteries arranged along a coaxial axis. However, other power sources (e.g., a.c. power) are also contemplated. A switch means 24 controls power from the power source 20 to the light source assembly 14.

[0020] The light source assembly 14 includes at least one (1) semiconductor light source (e.g., a light emitting diode (“LED”)) 26, which is electrically connected to the power source 20 via a printed circuit board (“pcb”) 28 mounted substantially at the open end 16 of the housing 12. More specifically, the at least one (1) light source 26 electrically communicates with circuitry on the pcb 28 which electrically communicates with the power source 20. The pcb circuitry regulates electrical power supplied by the power source 20 to the at least one semiconductor light source 26.

[0021] In the preferred embodiment, the light source assembly 14 includes three (3) semiconductor light sources 26a, 26b, 26c. The semiconductor light sources 26a, 26b, 26care seated and secured in respective individual reflector wells 30a, 30b, 30c. Respective individual lenses 34a, 34b, 34care secured to open ends of the wells 30a, 30b, 30c, respectively. More specifically, the lenses 34 are coupled substantially directly over the wells 30. In this manner, maximum efficiency of the lenses 34 is achieved. Each of the wells 30 is shaped and oriented to direct light produced by the respective semiconductor light source 26 to a predefined direction (e.g., toward a target area 36). More specifically, the wells 30 are designed such that the semiconductor light sources 26a, 26b, 26care surrounded by the wells 30a, 30b, 30c, respectively. The wells 30 encompass and rise above the light sources 26a, 26b, 26cto collect solid angles of light that are not filled within the optic designated for the light sources 26a, 26b, 26c. Furthermore, the lenses 34 act to direct the light toward the target area 36.

[0022] In the preferred embodiment, the lenses 34 are either multiple refractive, refractive/diffractive hybrid lenses, or fresnel lenses. Furthermore, the lenses 34 provide direct light refraction to the respective semiconductor light sources 26 such that the semiconductor light source 26 is imaged between the die (bottom face) and the top of the semiconductor light source assembly 14. In this manner, the light is directed and focussed toward the target area 36.

[0023] Preferably, the lenses 34, reflector wells 30, and semiconductor light sources 26 of the light source assembly 14 are matrixed to form a “honeycomb” array pattern.

[0024] The matrixed form is designed so as to optimize illumination efficiency and package size for minimum volume. However, other designs for the light source assembly 14 are also contemplated.

[0025] The design of the present invention maps the reflector wells 30 and lenses 34 to multiple semiconductor light sources 26 to create uniform, bright beam pattern at the target area 36.

[0026] The invention has been described with reference to the preferred embodiment. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.