US3724346A

US3724346A - Reflector extension for lamp unit

Info

Publication number: US3724346A
Application number: US00182625A
Authority: US
Inventors: D Armstrong
Original assignee: GTE Sylvania Inc
Current assignee: GTE Sylvania Inc
Priority date: 1971-09-22
Filing date: 1971-09-22
Publication date: 1973-04-03
Anticipated expiration: 1990-04-03
Also published as: JPS4873141A

Abstract

A disposable reflector extension for a flashcube comprising a sheet of reflective material having an arcuate portion adapted for forming a funnel-shaped reflector and a strip portion adapted for shaping a mounting hook to hold the funnel-shaped reflector onto the face of a flashcube.

Description

United States Patent [1 1 Armstrong 11] 3,724,346 1 1 Apr. 3, 1973 154] REFLECTOR EXTENSION FOR LAMP UNIT [75] Inventor: Donald E. Armstrong, Williamsport,

[73] Assignee: GTE Sylvania Incorporated, Danvers.Mass.

[22] Filed: Sept. 22, 1971 [21] App1.N0.: 182,625

[52] 11.8. C1. ..95/1l L, 240/1.3, 240/103 R [51] Int. Cl. ..G03b 15/02, F21v 7/18 [58] Field of Search.,...95/1l L; 240/13, 2 C, 103 R,

[56] References Cited UNITED STATES PATENTS Daymon ..240/103 R 2,785,290 3/1957 Terry ..240/104 X 2,768,284 10/1956 Woolley ..240/1.3 X 2,757,317 7/1956 Harlan 1 ..240/1.3 2,096,856 10/1937 Nuchterlein... ..240/2 C 2,976,511 3/1961 Lipsitz ..240/1.3 X

Primary Examiner-Robert P. Greiner Attorney-Norman .l. OMalley et a1.

57 ABSTRACT A disposable reflector extension for a flashcube comprising a sheet of reflective material having an arcuate portion adapted for forming a funnel-shaped reflector and a strip portion adapted for shaping a mounting hook to hold the funne1-shaped reflector onto the face of a flashcube.

2 Claims, 3 Drawing Figures REFLECTOR EXTENSION FOR LAMP UNIT BACKGROUND OF THE INVENTION This invention relates to lamp units and reflectors therefor, and more particularly to reflector extensions for photographic lamp units, such as a flashcube.

Over the years the advances made in photographic equipment and photographic light sources have been many and significant, not the least of which has been miniaturization. Cameras have become more and more compact, and photoflash lamps have become smaller and smaller. Of major importance during the past few years in subminiaturizing lamp types and simplifying and automating both amateur and professional photography has been the development of the small photographic flashlamp units referred to as flashcubes. As described in US Pat. Nos. 3,244,087 and 3,358,131, a flashcube comprises: a container having a plurality of closed transparent sides; a plurality of reflectors disposed in the container, one along each side thereof; and a photoflash lamp disposed in operative relationship with respect to each of the reflectors. In units intended for battery operatedflash systems, each lamp includes a filament-type electrical ignition system. In the case of non-electrical flash systems, percussive-type lamps, such as described in US. Pat. No. 3,535,063, are employed in multi-lamp cubical units having respective pre-energized striker springs for each lamp, as described in US. Pat. No. 3,597,604.

Although the miniature lamp and reflector arrangement of the flashcube provides quite adequate lighting for most photographic applications, situations do arise where more light is required to extend the range of acceptable flash exposure distance. Such is the case, for example, when greater than normal distances are required to properly encompass the subject for indoor exposures. Occasions for requiring additional light output can arise more often when taking outdoor night pictures, as the acceptable exposure distance is narrowed due to the absence of reflectance that is obtained from the walls and ceiling in indoor flash exposures.

SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide means for obtaining more usable light from a reflector-backed lamp unit.

A principal object of the invention is to provide means for extending the useful distance range of photographic lamp units, and in particular the flashcube.

Another object is to provide an inexpensive and easy to use means for obtaining more usable light from a flashcube for situations that require more light for acceptable exposure.

These and other objects, advantages and features are attained, in accordance with the principles of this invention, by providing an inexpensive reflector extension that can be mounted quickly and easily on a lamp unit, such as a flashcube, for significantly increasing its usable light output. Briefly, the extension device comprises a sheet of reflective material which is either preformed or adapted to be formed into a funnelshaped reflector, and a strip of sheet material connected to this reflector and preshaped or adapted to be shaped as a mounting means for holding the reflector in a desired position on the lamp unit. Preferably, the

reflector extension is initially supplied as a single flat sheet of disposable reflective material which is adapted for easy assembly into its operative configuration.

BRIEF DESCRIPTION OF THE DRAWINGS This invention will be more fully described hereinafter in conjunction with the accompanying drawings, in which:

FIG. 1 is a plan view of a blank adapted to be assembled into a reflector in accordance with the invention;

FIG. 2 is a side view of an assembled reflector extension mounted on a flashcube (shown in phantom) according to the invention; and

FIG. 3 is a front elevation of a camera having a flashcube upon which is mounted a reflector extension according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT A fixed reflector extension attached to or separate from the camera could be a combersome and somewhat bulky addition. On the other hand, if the extension were relatively simple, inexpensive and disposable, it would appear to provide an item more desirable to the photographer, since it is generally needed only in special photographic situations. The present invention provides a reflector extension of the later type.

In a preferred embodiment shown in FIG. 1, the reflector extension is initially supplied as an unassembled blank comprising a single flat sheet 10 of disposable reflective material. For example, the blank may comprise a flat die-cut piece of polished aluminum foil, metalized paper, or possibly metalized plastic sheet. Sheet 10 has an arcuate-shaped portion 12 having a tab 14 at one end and a slot 16 at the other end. Tab 14 has a transverse fold line 18 at its juncture with the arcuate portion 12, and slot 16 is adapted to receive the tab 14.

Sheet 10 also includes a strip portion 20 which extends radially inward from the arcuate portion 12. A first transverse fold line 22 is provided at the juncture of the strip and arcuate portions, and a second transverse fold line 24 is provided at a predetermined distance A from the free end of strip 20.

The disposable reflector extension sheet 10 may then be readily assembled for use, as illustrated in FIGS. 2 and 3, whereby arcuate portion 12 is formed into a funnel-shaped reflector 12' and strip 20 is formed into a hook to hold the reflector 12 on a lamp unit, such as the flashcube 26 shown in phantom in FIG. 2. More specifically, the funnel-shaped reflector is evolved by inserting tab 14 into slot 16 and bending over the tab 14 on the underside. Then by folding strip 20 at

lines

22 and 24, a hook 20 may be formed to hold the funnelshaped reflector 12' and the tab 28 formed by the fold at line 24. The reflector may then be used as needed and then disposed of or unfolded for later use.

With respect to dimensions, a suitable reflector extension for a flashcube having a face approximately 1 inch square can be provided by a funnel-shaped configuration (see FIG. 2) having a depth B of about 1 inch and a maximum diameter C of about 2 inches. The minimum diameter of the funnel, of course, is about 1 inch. Referring to dimension A in FIG. 1, a one-quarter inch tab 28 on hook 20 has been found satisfactory for mounting purposes.

FIG. 3 shows a front view of the reflector funnel 12' as mounted on a flashcube 26, which is operatively connected to a camera 30. The reflector extension is positioned on the flashcube with the small circular end 32 of the funnel 12' resting against the face of the flashcube in general alignment with the quasi-circular periphery of the reflector within the flashcube.

Photometric evaluation of several concepts of disposable extension reflector designs has indicated the above described configuration as the most efficient. This embodiment revealed a surprising 70 percent increase in usable light and a 75 percent increase in total light, while simple barn door designs of both flat and curved arrangements revealed only a to percent increase in light output. This additional light, which is equivalent to almost one f-stop, permits a 25-30 percent increase in the maximum recommended distance for simple cameras, provided needed light for acceptable exposure which is lost due to poor reflectivity of room surroundings in the normal picture range, or adds the necessary light for equivalent outdoor exposures.

Although the invention has been described with respect to a certain embodiment, it will be appreciated that modifications and changes may be made by those skilled in the art without departing from the true spirit and scope of the invention. For example, the strip portion need not be of reflective material, and it may comprise a separate piece which is hingedly attached to the arcuate portion 12 by means other than vertical fold line 22. The arcuate portion 12 may be secured in a funnel configuration by means other than tab 14 and slot 16, for example, some type, of adhesive may be employed. Further, the reflector extension may be initially provided in a completely assembled state, and it may be a non-disposable, non-collapsible device, with the funnel-reflector and mounting hook pre-formed of a thin sheet metal material. Also, the reflector extension is not limited to use with a flashcube but may be employed on any of a wide variety of lamp unit types for increasing light output. For example, a reflector extension according to the invention could be mounted on the substantially box-shaped housing of the movie light described in U.S. Patent (allowed, Ser. No. 698,045, filed Dec. 19, 1967).

What I claim is:

l. A reflector extension for increasing the light output from a flashcube comprising, a single flat sheet of reflective material having an arcurate portion for forming a funnel-shaped reflector and a strip portion extending radially inward from said arcuate portion, said arcuate portion including means for securing the funnel-shaped configuration thereof, and said strip portion having a first transverse fold line at the juncture of said strip and arcuate portions, whereby said strip is hingedly connected to said arcuate portion, and a second transverse fold line at a predetermined distance from the free end of said strip portion, whereby said strip is adapted for forming a mounting tab for holding said' reflector onto the face of said flashcube, said arcuate portion being adapted when funnel-shaped to substantially increase the light output from said flashcube.

2. A reflector extension according to claim 1 wherein said means for securing is a tab at one end of said arcuate portion and a slot at the opposite end, said slot being adapted to receive said tab upon the forming of said reflector to thereby secure the funnel-shaped configuration thereof.

Claims

1. A reflector extension for increasing the light output from a flashcube comprising, a single flat sheet of reflective material having an arcurate portion for forming a funnel-shaped reflector and a strip portion extending radially inward from said arcuate portion, said arcuate portion including means for securing the funnel-shaped configuration thereof, and said strip portion having a first transverse fold line at the juncture of said strip and arcuate portions, whereby said strip is hingedly connected to said arcuate portion, and a second transverse fold line at a predetermined distance from the free end of said strip portion, whereby said strip is adapted for forming a mounting tab for holding said reflector onto the face of said flashcube, said arcuate portion being adapted when funnel-shaped to substantially increase the light output from said flashcube.