EP1438533B1

EP1438533B1 - Device for illuminating a generally flat surface

Info

Publication number: EP1438533B1
Application number: EP02786519A
Authority: EP
Inventors: James F. Bennett, Jr.
Original assignee: LightWedge LLC
Current assignee: LightWedge LLC
Priority date: 2001-10-26
Filing date: 2002-10-25
Publication date: 2010-01-06
Anticipated expiration: 2022-10-25
Also published as: JP2005507144A; EP1438533A4; EP1438533A1; WO2003036164A1

Description

The present invention relates to a device for illuminating a generally flat surface according to the introductory part of claim 1.
Portable illuminating devices are wll known and have various and sundry configurations and potential uses. One type of such device is commonly referred to as a book light and essentially comprises a small light weight portable light-generating lamp adapted to be attached or otherwise supported in close proximity to a book, magazine or the like being read, so as to illuminate the pages thereof. Representative examples of such book lights are disclosed in U.S. Patent Nos. 4,443,042 ; 4,598,340 ; 4,680,681 ; 5,280,416 ; 5,442,528 ; 5,695,271 ; 5,921,664 ; Des. 414,574 ; 6,022,119 ; and 6,213,618 . Typically, such devices are intended to direct a targeted beam of light only at the reading material so as to minimize or avoid altogether inconveniencing or bothering others. Thus, one use promoted for such book lights is for reading in bed without the necessity of utilizing a table lamp so as to avoid interfering with a partner's ability to sleep.
While such book lights are generally effective for such purpose, the known devices are still inconvenient in that the light, although of lesser lumens than table lamps, still is emitted in an undiffused manner and may still bother others in the vicinity. Attaching the devices to books or magazines is also sometimes inconvenient and unwieldy despite the small size and light weight of such devices.
GB-A 1 232 977 discloses a device for illuminating a generally flat surface according to the introductory part of claim 1. The light source in the form of lamps surrounded by reflectors is spaced from the enlarged end of the tapered illuminating body.
US-A 5 499 165 discloses a linear light source which is mounted in an arcuate groove provided in the enlarged end of a tapering illuminating body.
From US-A 5 639 156 it is known to secure illuminating sources about the perimeter of a sheet assembly which serves as an illuminating body. The illuminating sources are spaced to the edges of the illuminating body.
US-A 2 358 203 discloses an electric lamp arranged in a spaced relationship to an end of a transparent sheet service as illuminating body.
US-A 4 751 615 discloses a tapering illuminating body having an opening at its enlarged end which is open to the enlarged end as well as to the upper side and the lower side.
It is an object of the present invention having an enhanced internal deflection of light within the illuminating body.
This object is solved by the features of claims 1.
According to the present invention the light source is one or more light bulbs, e.g. LEDs which transmit the light three-dimensionally into and through the illuminating body. It is further preferred that the light bulbs have a frosted globe, and that the edge of the illuminating body into which the bulb is received also be textured, for assisting in diffusing the light from the bulbs.

Fig. 1: is a perspective view of an illuminating device not in accordance with the present invention, shown in use overlying a page of a book being read so as to illuminate the page;
Fig. 2: is a front elevational view of the illuminating device of Fig. 1, with the housing thereof partially in cross-section;
Fig. 3: is a side elevational view of the illuminating device of Fig. 1 and 2, and
Fig. 4: is a perspective view of an illuminating device in accordance with a preferred embodiment of the present invention, shown with the housing thereof partially broken away.

Referring now to the accompanying drawings and initially to Figure 1, an illuminating device not in accordance with the present invention adapted particularly for use as a book light is indicated in its totality at 10. The illumination device 10 basically comprises a housing 12 which supports an illuminating body 14 extending outwardly from the housing 12, and also contains an arrangement suitable for generating a source of light, indicated overall at 16.
The illuminating body 14 fundamentally is contemplated to comprise a transparent body formed of a material capable of conducting light and dimensioned and configured to overlie the item intended to be illuminated, e.g., in a rectangular shape in front elevation corresponding to a typical page of a published book. As is known, certain thermoplastic resins, such as various acrylic and polycarbonate resins, have the inherent capability of conducing light throughout the material and, hence, it is contemplated and preferred that the illuminating body 14 be fabricated of such material, although the present invention is not intended to be limited to these materials but can potentially utilize any illuminating body made of any other transparent material capable of conducting light Advantageously, the illuminating body is further configured to deflect a substantial portion of the conducted light within the illuminating body 14 onto the underlying book page or other surface to be illuminated. For this purpose, the illuminating body 14 is preferably formed in a wedge shape tapering from an enlarged end 14A narrowingly to an edge 14B of a substantially reduced cross-sectional thickness at the opposite end of the illuminating body 14.
The housing 12 preferably is substantially hollow in order to receive and secure the enlarged end 14A of the illuminating body 14, e.g., by screws and other fastening means (not shown), and also to contain the light source arrangement 16 in immediate adjacency to the enlarged end 14A. The housing 12 preferably is configured as compactly as possible to occupy a minimal portion of the front elevational surface area of the illuminating device 10, but in the accompanying drawing the housing 12 is illustrated more schematically and on a more enlarged scale for better clarity and understanding of the individual components of the illuminating device 10.
The light source arrangement 16 may comprise any suitable combination of components capable of generating visible light and applying such light to the enlarged end 14A of the illuminating body 14 contained within the housing 12 so as to conduct the light into and through the illuminating body 14. By way of example, but without limitation, the light source arrangement 16 may comprise a common miniature light bulb 18 supported centrally within the housing 12 immediately adjacent the enlarged end 14A of the illuminating body 14 and connected in series with a storage battery 20 and a manual on-off switch 22 by a simple DC-form of electrical wiring circuit, indicated generally at 24, for selective energization and deenergization of the light bulb 18.
The operation of the illuminating device 10 may thus be readily understood. Upon manual actuation of the switch 22 to close the electrical circuit 24, the battery 20 supplies electrical power to the light bulb 18, thereby energizing the light bulb 18 to emit visible light. Because the housing 12 is enclosed and preferably fashioned of an opaque material, the emitted light is contained within the housing and, due to the immediate proximity of the light bulb 18 to the enlarged end 14A of the illuminating body 14, the light is substantially conducted into and through the illuminating body 14 toward the opposite narrowed end edge 14B. However, because of the tapering wedge shape of the illuminating body 14, a substantial amount of the conducted light is deflected downwardly and emitted from the underside of the illuminating body 14. Thus, with the illuminating device 10 placed in overlying relation to a generally flat surface, such as a page of a book, as depicted in Figure 1, the light conducted within the illuminating body 14 is substantially applied directly and primarily to the underlying surface, thus readily facilitating illuminated viewing of the surface through the transparent body 14.
With reference now to Figure 4, a contemplated embodiment of an illuminating device according to the present invention is shown in a perspective view and indicated in its totality at 110. As with the embodiment of Figures 1-3, the illumination device 110 basically comprises a housing 112 which supports a rectangularly wedge-shaped illuminating body 114 formed of a suitable light-conductive thermoplastic resin. In Figure 4, the housing 112 of the illumination device 110 is partially broken away to reveal the operative internally-supported light generating arrangement 116. Basically, the light generating arrangement 116 comprises a miniature circuit board which supports a pair of miniature LED-type light bulbs 118 in laterally spaced arrangement, a pair of ordinary dry cell batteries 120, and a manual on-off switch 122. In this embodiment, the light bulbs 118 project directly and snugly into correspondingly spaced and configured bores 125 formed in the immediately adjacent enlarged end 114A of the illuminating body 114. Advantageously, in this manner, the light bulbs 118 are completely surrounded by the resinous material of the illuminating body 114 whereby the light transmitted by the bulbs is effectively conducted into the body 114 three-dimensionally, i.e., longitudinally in the lengthwise direction of the body, laterally in the widthwise direction of the body, and transversely in the direction of the body's thickness. In tum, the internal deflection of the conducted light within the illuminating body 114 is enhanced over that accomplished by a light bulb merely being oriented adjacent, so as to be shown at, the enlarged end 114A of the illuminating body 114. It is further contemplated in this embodiment that the outer globe 118A of each light bulb 118 should have a frosted or otherwise textured surface effect so as to diffuse the transmitted light and prevent any tendency of the light to conduct in noticeable streaks or beams. In conjunction therewith, the edge of the enlarged end 114A, the interior surfaces of the bulb - receiving bores 125, as well as a portion of the front and rear faces, of the illuminating body 114, are textured, as indicated at 129, to further enhance diffusion of the emitted light from the bulbs.
According to another feature of the illuminating device 110 in the embodiment of Figure 4, the housing 112 includes lateral arms 112A which enclose and project partially along the apposite lateral side edges 114C of the illuminating body 114 adjacent its enlarged end 114A. In conjunction therewith, the side edges 114C of the illuminating body 114 are formed with laterally projecting ears 115, which are received snugly in recessed receptacles 113 formed in the arms 112A of the housing 112. The mating engagement of the ears 115 of the illuminating body 114 in the receptacle recesses 113 of the housing 112 effectively enhances the securement of the housing 112 with the illuminating body 114. Additionally, the projecting arms 112A of the housing 112 are configured with lengthwise channels 117 along the front and back sides of the arms 112A to matingly receive in removable fashion opposing legs 127A of abutment devices 127. When thusly secured in place on the arms 112A, the abutment devices 127 form forwardly and rearwardly projecting flanges along the side edges 114C of the illuminating body 114 which can function as rests to engage against a book or other item to be illuminated so as to hold the illuminating device in overlying relation thereto.
Persons skilled in the relevant art will readily recognize and understand that the present invention is susceptible to numerous embodiments, uses and modifications beyond the specific form of book light disclosed and illustrated herein. Fundamentally, the illuminating device 10 of the present invention may be embodied in various sizes and configurations as suitable for use in illuminating virtually any generally flat surface in virtually any application wherein it is desirable to avoid emitting any significant quantity of the conducted light beyond the underlying surface to be illuminated and viewed. For example, alternative embodiments for military and/or industrial applications and uses are contemplated to be possible. Similarly, it is contemplated that the housing 12 may be equipped or configured with a clip-like or similar device capable of engaging over a book so as to facilitate hands-free retention of the device in place overlying a page of a book. These and other embodiments, applications and modifications of the present invention are contemplated to be within the scope and substance of the invention.
The advantages of the present invention over known forms of book lights and other illuminating devices will be readily apparent. The device is simple and easy to use and effectively focuses the majority of the emitted light directly on the surface to be illustrated with minimal emission of light beyond the surface so as to avoid interfering with or bothering other persons in the vicinity. Because the present invention does not suffer the disadvantage of diffusion of the emitted light away from the illuminated surface, the present invention may potentially illuminate as effectively as or better than conventional devices while utilizing a smaller and lower wattage bulb than conventional lights, thereby realizing an increased battery life in contrast to known devices.
It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the scope of the present invention as defined in the appended claims. Accordingly, while the present invention has been described herein in detail in relation to its referred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent managements, the present invention being limited only by the claims appended hereto and the equivalents thereof.

Claims

A device (110) for illuminating a generally flat surface essentially without emitting significant light beyond the surface, comprising
a light source (118) comprising at least one light bulb and
an illuminating body (114) for generally overlying the surface being illuminated, the body comprising a transparent light conductive material configured to receive and deflect light from the light source onto the surface to be illuminated and having a generally tapering wedge-shape, further comprising
a housing (112) containing the light source and supporting the illuminating body and the light source in assembly with one another, characterized in that the illuminating body (114) defines at least one recess bore (125) extending from an enlarged end (114 A) of the body in the direction of the taper of the body which recess bore is configured compatibly with the light bulb (118) for closely receiving and essentially surrounding the light bulb for transmitting the light from the light bulb threedimensionally into the body.
An illuminating device according to claim 1, wherein the housing (112) and the illuminating body (114) have mating projections (115) and receptacles (113) for securing the housing (112) and the illuminating body (114) together.
An illuminating device according to claim 1 or 2, further comprising a battery (120) for selectively energizing the light source (118).
An illuminating device according to claim 1, 2 or 3 wherein the illuminating body (114) is dimensioned and configured to overlie and illuminate a page of a book for reading in the absence of other light.
An illuminating device according to claim 4, further comprising an abutment attachable to the illuminating body (114) for engagement against the book for resting the illuminating device on overlying relation to the page.
An illuminating device according to anyone of claims 1 to 5, wherein the illuminating body (114) comprises a magnifying area.
An illuminating device according to anyone of claims 1 to 6, wherein the at least one light bulb (118), the light bulb having a frosted globe for diffusing the light from the light source.
An illuminating device according to anyone of claims 1 to 7, wherein the illuminating body (114) includes a textured portion adjacent the light source (118) for diffusing the light therefrom.