DE29706117U1 - Contour spotlight for pictures - Google Patents

Description

-2- Contour straightener for images

Spotlights are used to illuminate pictures, which illuminate the exact format of the picture without also illuminating the surrounding area. Their use is limited to representative purposes only, as their purchase costs are high. The effect is extraordinarily great and not comparable with conventional picture lighting. It would therefore be very desirable if there were simple, inexpensive contour spotlights for all pictures in everyday life, even in private areas, in order to bring these pictures to their full advantage.

The radiators proposed here contain components that are known in detail. It is the combination and interaction of all these parts that surprisingly meet all requirements: low overall costs with high functionality and performance. Given the multitude of conceivable possibilities and unsuccessful attempts to date, this result was not to be expected.

It was found (Fig. 1) that all the necessary parts, such as lamp (2), diaphragm (3) and lens (4), can be easily and inexpensively installed in a tubular housing (1). The tube (1) can be made of standardized commercial materials such as iron, aluminum and plastic. A circular cross-section is very suitable. The installed parts are hardly visible and the spotlight can be installed anywhere in the room. The simple shape of the housing is unobtrusive, so that only the effect of the image stands out.

You can also only put the optics, i.e. the aperture and lens, in the tubular housing (Fig. 2) and use this part alone as an attachment for existing lamps. There are a number of suitable spotlights on the market, especially halogen lamps, which are very inexpensive. The optical attachments can be easily attached to the spacer and protective rings (8), e.g. with 3-4 metal brackets (9) that engage in the ring. This allows the attachment to be held in place and also rotated freely in order to optimally align the contour aperture to the image perspective.

The optical part of the contour spotlight can also be housed in a tubular housing with a conical taper and can serve as an attachment and lampshade at the same time (Fig. 3). The shade (1) is placed on the spacer rings (8) of the commercially available halogen lamps and at the same time shields the scattered light from the sides. With standard lampshade paper, no overheating occurred even after a long period of use and the light shining through is pleasant. The shade is given sufficient stability by the round lens (4) inserted at the front and by resting on the round spacer ring (8). If the shade can be made easy to remove, the lamp and optical part can be easily maintained.

High demands are placed on the contour aperture. Not only do the images have different formats, but the four boundaries appear in all shapes of random squares when viewed from the spotlight (Fig. 4). The technical effort required for such contour apertures has therefore been very high. In conjunction with the tubular housing, a simple solution was found at the same time. If you make four slots (7) around the circumference into which you insert four variably adjustable apertures (3), you can mask out all the different squares.

The plug-in panels can be made self-locking, which makes handling easier and reduces production costs. A spring force on the panels in the slot has proven to be very effective (Fig. 5). If the panel material is folded over at one end (10) and inserted into the slot, a clamping effect is created in the slot that is effective in any position. The plug-in panels are given additional stability by their circular overlap on the inside of the panel cutout (11). This multiple self-locking allows individual panels to be adjusted without interference.

Experiences and tips

Further useful experiences and tips are given below. The housing in Fig. 1 consists of a piece of pipe 210 mm long, 0 60 mm, wall thickness 2 mm, made of aluminum.

The halogen lamp (2) with socket (6) is supported by a web made of aluminum flat strip (5), which is set into grooves in the wall at the beginning of the tube (clamp connection). The aperture is 100 mm later and the lens with a 100 mm focal length is about 103 mm after the aperture. To set up and align the spotlight in the direction of the image, the tube can have two fixed, low feet attached to it at the front and a single, height-adjustable foot made of flexible soft iron strip attached to it at the back. However, other simple brackets can also be attached to the tube.

Since the housings are open at the back and are higher than the front part with the lens, the heat can easily escape.

Fig. 3 shows a conical housing with only a cover and lens, which also functions as a lampshade. Commercially available paper has proven to be a very good material for the cover. The heat is dissipated particularly easily through the large opening at the back. The cover is placed on the spacer rings of the halogen lamps, 30 mm after this there are the notches for four plug-in covers and after a further 103 mm there is the lens with a 50 mm diameter.

The aperture slots in the tubes have a width of 1.5-2 mm and the slot length should be as large as possible in order to be able to illuminate large images with sharp contours using wide apertures if necessary.

-A-

The plug-in panels can also be made of different materials, e.g. aluminum sheet or cardboard. The outer end is folded over to ensure self-locking and cut off at the corners to prevent mutual obstructions when the panels are tilted. Subsequent corrections or straightening of the contour edge are possible at any time with scissors when using the thin material.

The required aperture width BW, the distance between two opposite aperture edges, is in a simple relationship to the other sizes, e.g. image size BG=45 cm, image distance BA=300 cm and lens focal length LB=10 cm.

„».,, BG-LB ,45-10 _, _r ·
^BW ~ BA " 300 " ¹ ' ^5cm

Compared to normal 220V light bulbs, 12V halogen lamps emit more light and less heat with the same power consumption, and with cold light reflection with 8-12° narrow beams, the light is used particularly well. Their service life is 2000-3000 hours and the electricity costs of a 20 watt lamp, for example, are only « 0.4 Pf./hour. 35 watt lamps are only required in brighter rooms, with very large pictures or with large picture distances. The radiation field emanating from the reflectors should be evenly bright and must not have a dark shadow in the middle. The lamp diameter depends on the maximum desired aperture width BW. In general, small lamps with 0 31 mm are sufficient, but 0 51 mm can also be easily accommodated in the 0 60 mm housing.

For the optics, simple bi-convex lenses with a focal length of 100 mm (10 diopters) and 0 50 mm are sufficient. In general, a fixed installation is sufficient for focusing at medium image distance. Slight blurring of the contours at other image distances is not a problem.

Installation and connections

To avoid reflections from glass panels and sometimes glare, the spotlights should be mounted slightly higher than the pictures. For many pictures and spotlights, e.g. in exhibitions, stands with an upper support plate on which a ring transformer for e.g. 10-15 spotlights can be placed are suitable. With a dimmer, the brightness of the pictures can be optimally adjusted in relation to the general brightness of the room.

Prices

The material costs and assembly costs are low, so that the unit price is only a fraction of the devices known to date.

Claims (4)

■i « V * -1- Setcnmsprüche 1. Contour radiator, whose optical parts are housed in a tubular housing. 2. Contour spotlight according to claim 1, which only has a cover and lens and serves as an attachment for existing lamps. · 3. Contour spotlight according to claim 1 and 2, the housing of which is conically reduced and simultaneously serves as a lampshade, 4. Contour radiator according to claims 1-3, on whose tubular circumference four slots with four adjustable plug-in panels are mounted.