DE1183035B - Luminaire with one or more tubular lamps and a clear cover made of plastic glass with a prismatic surface - Google Patents

Description

Luminaire with one or more tubular lamps and one clear cover made of plastic glass.-with prismatic surface It is known Luminaires with tubular lamps, in particular fluorescent lamps, with covers made of clear plastic glass, which on one surface in the longitudinal direction, d. i. the lamp direction, have running prism strips. Usually have these longitudinal prismatic strips have the cross-section of an isosceles triangle. A preferred distribution of the luminous flux is achieved through the prismatic strips across the lamp axis and in a downward angular range. One can in this way direct the light emanating from the lamps in preferred directions and shield other directions.

As a 'modification of the continuous, lengthways Prism strips are known as step-like prism strips, which are also run through in profile. The light distribution of these prism strips is similar to the aforementioned. However, there is each one of the continuous prismatic strips Kind of disadvantage that a relatively clear view of the interior of the luminaire is given, so that the built-in parts of the lamp are undesirably visible will.

It is already known to achieve prismatic surfaces except the continuous longitudinal prismatic strips of also running in the transverse direction Provide triangular cross-section, such that pyramidal prismatic Elevations with a square base are created. Instead of the transverse grooves you can also be provided in the same form of horizontal stripes, with the same pyramids Form with a qua * atisgier base area, but as prismatic depressions. aside from that it is known, individual pilaster-shaped or arched prismatic elevations or Arrange wells with a circular or elliptical outline. With all of them The mentioned cases of single prisms is essentially the insight into the interior of the luminaire prevented. The desired preferred distribution of light across the lamp axis as well as in angular ranges downwards (deep-wide radiation) is known with these However, single prisms are not achieved.

The aim of the present invention is to design the prismatic surface of the clear plastic covers in a luminaire with tubular fluorescent lamps, in particular in the form of rods, so that on the one hand the required deep-wide radiation is achieved, but on the other hand it is prevented from looking into the interior of the luminaire. The invention is based on a lamp with one or more leading # riigeri- tampen, 'ins- special leuclite lamps "And - a clear cover made of plastic glass which = on, a top = area in the longitudinal direction, d .. 'iparällel zur'Lampen = direction 'running prismatic tires' which through transverse prismatic grooves or prismatic stripes are crossed. The I mark of the finding is that the 'distance in the transverse direction running prism # illän or prisms - stripes from each other 'derärt-g # he is chosen äls the distance between the longitudinal prism strips from each other that individual piisffaiiscfie elevations or depressions ofchteekigeni G'rundriß 'with an aspect ratio 'Nron'el'zugWeise 1: 2 to 1: 4 arise. After @ einf =, preferably pn out Leading form 'of the invention' should be the prismatic Surveys or deepening ti "e@tt.va die: Form of a Have hip roofs; whose 'f first, parallel to the Lamp direction runs: In principle 'with di @ -' the present invention from the well-known stripes of lagerism went. The course of the - ##. Angular prism stripes is through the transverse prism grooves or Although the prismatic strip should be interrupted, it is done the interruption in wesenet; h'larger. Spacing as it is known so far; in such a way that Rectangles in the specified aspect ratio correspond to stand. It has been shown to be outstanding; that in contrast to the Auroh ehenderi -Trisms- glimpse into the luminaire housing far is avoided and that nevertheless essentially the same deep-wide radiation is achieved over the continuous prism strip. This is based on the fact that the measures according to the invention increase the prism surfaces radiating transversely with respect to the lamp length, whereas the surfaces radiating towards the end faces of the lamp are reduced overall.

This relation can be increased still further by using the transversely radiating prism surfaces flatter, the front radiating surfaces however, forms steeper.

The invention is referred to in various exemplary embodiments explained in more detail on the drawings.

A b b. 1 shows a plan view and sections of the invention individual prismatic elevations; A b b. 2 shows prismatic depressions of FIG same shape and arrangement as A b b. 1; A b b. 3 shows a prismatic elevation in the form of a pyramid with a rectangular base; A b b. 4 and 5 are modifications the prismatic elevations according to A b b. 1 or the depressions according to A b b. 2; A b b. 6 to 9 show sawtooth-like longitudinal prism strips.

In the embodiment according to A b b. 1, with 1 the longitudinal prism strips designated with their flat surfaces 2. 3 are transverse to triangular grooves with surfaces 4. The distances and angles of the grooves 3 are chosen so that occur on rectangular Grundrißflächen prismatic elevations on the shape of a hipped whose ridge, denoted by 6, runs in the longitudinal direction. Alpha is the apex angle of the grooves 3. It can be less than the apex angle beta of the longitudinal strips 1 .

In the embodiment according to A b b. 2, the longitudinal prism strips 10 with the surfaces 11 on both sides are crossed by the transverse prism strips 12 with the surfaces 13. This arrangement creates prismatic depressions of the same shape as according to A b b. 1.

With the same shape and dimensions, the optical effect is more prismatic Elevations and prismatic depressions are the same. However, increases are in the More advantageous in terms of cleaning. In addition, the question is answered, whether one chooses elevations or depressions, of seldom tool manufacture.

The in A b b. 3 illustrated prismatic elevation is a pyramid with a rectangular base.

The prismatic elevations according to A b b. 4 and A b b. 5 have essentially the roof shape with ridge, however, the surfaces 15 and 16 are the light to the end faces the lamp radiate out, either concave or convex.

In the case of the statements according to A b b. 6 to 9 are those to one side facing surfaces of the longitudinal prismatic strips are flatter than those after the other side facing surfaces. This creates a sawtooth-like cross-section Shape. With this design, the surfaces radiating to a transverse side become larger than the surfaces radiating to the other transverse side. These will be on shortest for vertical execution according to A b b. 6 and 7. According to A b b. 6 and 8 takes the width of the longitudinal, running prism strips from right to left, so that the right-facing surfaces of the prism strips become increasingly flatter. This measure is used to concentrate the light in certain right angle areas. ,.

When designing lamp covers with a prismatic surface, efforts are made to use technical means to achieve what is known as the brilliance effect. This is understood to be the effect on the eye of a large number of surfaces with different luminance. In the known pyramid prisms with a square base, the brilliance effect is often absent, since the four pyramid surfaces of the same size are each too small to be resolved by the eye with regard to their light effect, ie their brightness can be precisely detected. The eye often only perceives the sum of the primes with a uniform brightness. When using the roof shape according to the invention one creates significantly more favorable conditions with regard to the brilliance effect, since in the transition from the pyramid shape to the roof shape while maintaining the height, the areas radiating in the transverse direction to the length of the luminaire are significantly larger. You can enlarge the areas causing the brilliance by choosing a suitable angle by the areas, z. B. 4, the transverse grooves as possible with pointed and the surfaces, z. B. 2, the longitudinal prismatic strips can butt against each other as possible at an obtuse angle.

If the luminaire cover is roof-shaped single prisms, namely as Should have elevations, you can make the necessary indentations in the tool that you need in the production, generate with the help of a conical milling cutter. You leave the milling cutter to create a recess in the tool surface penetrate and move it by the length that the roof should have. In the tool this creates roof-shaped depressions with a substantially rectangular base area with larger flat side surfaces, but the smaller front surfaces are the roofs not flat, but curved in a conical shape. Those made with such tools Covers then have prismatic elevations of the same shape.

Claims (7)

Claims: 1. Lamp with one or more tubular Lamps, especially L, fluorescent lamps, and a clear cover made of plastic glass, which run on a surface in the longitudinal direction (parallel to the lamp direction) Has prism strips, which by transverse prism grooves or strips are crossed through, characterized in that the distance between the transverse direction Prism grooves or strips from one another is selected to be greater than the distance the longitudinal prism strips from each other, that individual prismatic elevations or recesses of rectangular plan with an aspect ratio of preferably 1: 2 to 1: 4 arise. 2. Lamp according to claim 1, characterized in that the prismatic elevations or depressions roughly the shape of a Have hipped roofs, the ridge of which runs parallel to the direction of the lamp. 3rd lamp according to claim 1, characterized in that the prismatic elevations or depressions have flat surfaces. 4. Light according to claim 1, characterized in that the surfaces radiating in the longitudinal direction are concave or convex. 5. Light according to claim 2, characterized in that the surfaces (11) of the longitudinal Prism strips form an angle in the range of 110 ° to 160 ° with one another. 6th Luminaire according to Claim 2, characterized in that the Surfaces are steeper than the surfaces radiating in the transverse direction. 7. Light after Claim 1, characterized in that the one side (main radiation direction) facing surfaces of the longitudinal prismatic strips are flatter than the to the other side facing surfaces, so that a sawtooth-like cross-sectional shape arises. B. lamp according to claim 7, characterized in that the rise angle of the flatter surfaces change steadily in the transverse direction.