EP1001210A1 - Imaging system for a projector with alterable focal length for use in stage or studio lighting - Google Patents

Abstract

A picture system (30) comprises a first lens member (31) and a second lens member (32) which can be slid relative to one another. There is a combination of an iris aperture (33), an aperture slider set (35) and a gobo- slide-in compartment located between a condenser system and the second lens member in the radiation path. The second lens member has a refractive power that is greater than, or equal to, twice, yet smaller than, or equal to, three times the refractive power of the first lens member.

Description

The invention relates to an imaging system changeable focal length for a headlight Stage / studio technology comprehensively a first, one Illuminated lens member facing and the Illumination location turned away, a light-generating Element facing second lens member, the first and the second lens member displaceable against each other are, as well as one between a condenser system and the second lens element in the beam path arranged combination of an iris, one Panel slider set and a gobo slot (Operating part).

Such imaging systems are for example in the Publication by J. Altmann: Presentation of various Headlight systems, published in the German magazine "Bühnentechnische Rundschau" Issue 3/1979, pages 20 to 23.

Using the aperture slide set different profile contours in the beam path generated and mapped by the imaging system become. The gobo slot serves for insertion of effect diaphragms in the beam path. It can be out there is a slide for receiving the gobo (s), one or more presets for recording from Gobos, which can be optionally in the Beam path of the headlight by moving the Slider can be brought.

Headlights are used for lighting, whose light cone depends on the setting at the lighting location have a different size can. The so-called scattering angle, as in DIN 5037 sheet 1, 2.3.1 is defined in one the largest possible area to be changeable. To do this achieve is with known imaging systems provided that the two lens members relative are displaceable to each other.

Furthermore, there is a refractive power distribution in known systems of the two lens members provided in such a way that the second lens member has a larger one Has refractive power as the first lens member.

Since practically only with known imaging systems Refractive power ratios are used that are smaller than two is the most feasible in practice Scattering angle variation range in known headlights limited.

In addition, known imaging systems exist Lens and aberration, for example spherical and / or chromatic aberrations. In addition, disturbing in the illuminating light cone Effects, for example in the form of uneven Illuminance distributions occur. this leads to that several different headlights for a very wide range of scattering angles can be used have to.

From DE 196 43 220 C1 and EP 0 828 111 A1 goes an imaging system with a variable focal length for a spotlight of the stage / studio technology of the Generic type, in which the second Lens member has a refractive power that is larger or equal to twice and less than or equal to that Is three times the refractive power of the first lens member and in which the iris diaphragm is the first to be imaged Element of the operating part closely adjacent to the second lens element is arranged. One with one such imaging system provided headlights the Stage / studio technology can be large Scattering angle range can be used. Problematic is, however, that due to the condenser system light rays emerging slightly converging complete illumination of the first to be imaged Element of the operating part closely adjacent to the second lens element arranged iris diaphragm, in particular an illumination of their edge areas, is not always guaranteed.

The invention is therefore based on the object Imaging system with variable focal length for a spotlight of the stage / studio technology of the Generic type in such a way that on the one hand as large a variation of the Scattering angle range, on the other hand a complete Illumination of the iris as well as the Effect panels and the gobos at optimal Mapping performance is made possible.

• das zweite Linsenglied eine Brechkraft aufweist, die größer oder gleich dem Zweifachen und kleiner oder gleich dem Dreifachen der Brechkraft der ersten Linse ist,
• die Irisblende ist nicht als erstes abzubildendes Element des Bedienungsteils dicht benachbart zu dem zweiten Linsenglied angeordnet.

This object is achieved according to the invention in an imaging system with a variable focal length for a spotlight of the stage / studio technology of the type described in the introduction by the features

• the second lens element has a refractive power which is greater than or equal to twice and less than or equal to three times the refractive power of the first lens,
• the iris diaphragm is not arranged as the first element of the operating part to be imaged closely adjacent to the second lens element.

Due to extensive tests and calculations showed that a refractive power distribution of the two Lens members such that the second lens member a Has refractive power that is greater than or equal to that Twice or less or equal to three times the Refractive power of the first lens member is for one as large as possible, in stage and studio lighting technology scattering angle range used at a optimal imaging performance particularly advantageous is. In addition, such Imaging system the lens / imaging errors described above minimized.

As for the arrangement of the iris to change the Light circle diameter compared to the others Elements of the control section are concerned based on extensive trials showed that they did not as the first element of the operating part to be displayed arranged closely adjacent to the second lens member should be. Other than that, however, are pure in principle the most varied of arrangements conceivable. An advantageous embodiment sees following arrangement behind the condenser system: Gobo slide-in compartment, iris diaphragm, aperture slide set. This arrangement not only has the advantage that in particular the peripheral areas of the iris completely be illuminated. It is particularly advantageous also that the slightly converting Light rays penetrate the shutter set in such a way that the free light passage opening in Aperture slide set can be kept smaller. As a result, the outer dimensions of the shutter set - calculated from aperture slide handle to aperture slide handle when the shutter is open - smaller become. This has in particular the constructive Advantage that the shutter slide in the wound Condition and with hanging and down inclined headlamp not on the headlamp bracket bump and thus the headlight bracket in his Width can be smaller, which makes the headlights makes it more manageable and easier to use.

Another advantageous embodiment sees following arrangement of iris diaphragm, gobo slot, Aperture slide set in the beam path behind the condenser system in front: iris diaphragm, diaphragm slide set, Gobo slot. This has the particular advantage that, for example, with a reduced power consumption of the light generating element e.g. a photosensitive Inserted paper into the gobo slot can be and thereby through the arranged in the beam path in front of the gobo slot Contour generated elements using the light sensitive Fix paper and then on a sheet can be transmitted, which as a fixed aperture when in use the headlight, e.g. during the theatrical performance is inserted into the gobo slot.

Another advantageous embodiment provides that on the shutter slide set another compartment is provided, in which a replaceable iris diaphragm or a gobo holder with a gobo or one Decorative perforated panel can be inserted. Here is of it assumed that the shutter set either in Interaction with focusing on one Iris diaphragm or a gobo projection come. Because of the close proximity of the shutter slides there is an iris or gobo good sharpness of the projected subject and the pushed off Contour. It is particularly advantageous that the iris diaphragm exposed to high temperatures if damaged can be replaced without the control part must be dismantled.

In principle, the most varied Refractive power ratios come into consideration.

However, the power ratio is preferred depending on the shape and luminance of the light-generating element of the headlight selected.

größer 2,15 und kleiner 2,45, insbesondere 2,3

größer 2,35 und kleiner 2,65, insbesondere 2,5

größer 2,65 und kleiner 2,95, insbesondere 2,8.

The magnitude of the refractive power ratio varies depending on the shape and the luminance of the light-generating element, which can be, for example, an incandescent filament of a halogen incandescent lamp or an arc of a xenon short-arc lamp or a daylight gas discharge lamp (metal halogen lamp), preferably within one of the following intervals:

greater than 2.15 and less than 2.45, in particular 2.3

greater than 2.35 and less than 2.65, in particular 2.5

greater than 2.65 and less than 2.95, in particular 2.8.

With regard to the design of the two lens elements, the most varied of embodiments are conceivable.
For example, both lens elements can comprise one or more lenses with spherical surfaces.

Another advantageous embodiment provides that the first and / or the second lens member a or comprise several lenses with aspherical surfaces.

In a further advantageous embodiment provided that the first and / or the second lens member Combinations of one or more lenses with include spherical and aspherical surfaces.

In another advantageous embodiment the first and / or the second lens member one of Center point changing towards the edge, for example decreasing or increasing Refractive index curve on.

Through this choice of lens elements, the through Lens / imaging errors arise disturbing Effects particularly effectively minimized.

This way it is possible to put the lenses on one Adjust headlight tube, which is usually rectangular or square. This is a consequence of that the light sources in most cases either an elongated arc or one have square or rectangular filament. The light source shape appears in a blurred form in the Area of the first lens element in the headlight tube as an image, with certain marginal areas one circular lens is only a small one Have luminance. Now that the cross section of the Headlight tube should be kept as small as possible, it is advantageous to e.g. a square or inscribe a rectangular lens element.

It is particularly advantageous that the two Lens elements are displaceable against each other in such a way that they are very tight in the maximum shifted state, are arranged adjacent to each other. This will a very large one with an optimal imaging performance Scatter angle variation range, which is defined as the ratio of maximum spread angle to minimum Scattering angle, possible. Such a scattering angle variation range could especially with the above described, known from the prior art Imaging systems have not yet been achieved. By are the imaging system according to the invention Scatter angle variation ranges from 1: 3 and more achieve while maintaining relatively good imaging properties of the imaging system. Here imaging errors are minimized.

With multi-lens systems, the lenses can different technical or optical glasses exhibit.

The lens links can be on the most varied Way, for example manually, against each other be moved. An advantageous embodiment the invention provides that the two lens members from one controlled by a control circuit Motor can be moved against each other.

The iris diaphragm is advantageously also one open and open motor controlled by a control circuit closable.

Further advantages and advantageous exemplary embodiments the invention are the subject of the following Description and the graphic representation some embodiments.

Fig. 1

eine schematische Darstellung eines ersten, von der Erfindung Gebrauch machenden Ausführungsbeispiels eines, in einem Scheinwerfer der Bühnen-/Studiotechnik verwendeten Abbildungssystems;

Fig. 2

eine schematische Darstellung eines zweiten, von der Erfindung Gebrauch machenden Ausführungsbeispiels eines, in einem Scheinwerfer der Bühnen-/Studiotechnik verwendeten Abbildungssystems und

Fig. 3

eine schematische Darstellung eines dritten, von der Erfindung Gebrauch machenden Ausführungsbeispiels eines, in einem Scheinwerfer der Bühnen-/Studiotechnik verwendeten Abbildungssystems.

The drawing shows:

Fig. 1

is a schematic representation of a first, from the invention use embodiment of an imaging system used in a spotlight of the stage / studio technology;

Fig. 2

a schematic representation of a second embodiment of the invention making use of an imaging system used in a spotlight of stage / studio technology and

Fig. 3

is a schematic representation of a third embodiment of the invention making use of an imaging system used in a spotlight of stage / studio technology.

As is apparent from the figures, includes a Spotlights for stage / studio technology e.g. Daylight gas discharge lamp 10, for example one Xenon short-arc lamp, or a halogen incandescent lamp, with a concave mirror 11 for focusing light, a condenser with two condenser lenses 21, 22 and an imaging system 30 with a first, the Lens member 31 facing illumination location, one second, facing away from the lighting location and the lamp 10 facing second lens member 32, the first and the second lens member 31, 32 so displaceable are that their distance can be changed, an iris diaphragm 33, a gobo slot 34, which the insertion different effects screens, and one Aperture slide set 35.

The light rays emerging from the condenser system 20 are slightly convergent. Illumination the iris diaphragm 33 and a strong decrease in illuminance Avoiding to the bezel edge is like in 1, provided that the iris diaphragm 33rd between the gobo slot 34 and the shutter set 35 is arranged.

In addition, the iris diaphragm 33 - as in FIG. 2 shown - also directly behind the condenser system 20 are arranged. This is followed by the Aperture slide set 35 and the gobo slot 34.

Finally, the iris diaphragm 33 can also be adjacent in FIG a designated storage compartment of the shutter set 35 may be arranged (Fig. 3), which but also the gobo holder 34 instead of the iris diaphragm 33 record with a gobo or with a decorative aperture can.

Above in the beam path of the imaging system 30 moreover, in most cases, a known one manually or controllable by motor Darkening device 40 is provided especially with gas discharge lamps, their brightness cannot be varied arbitrarily, one enables continuous darkening. Instead of this Darkening device 40 can be used Brightness control at the front end of the tube - in front the first lens element 31 in the tube - a fixed one known manually or controllable motor operable blind 50 with movable slats to be ordered. Through this blind a by introducing the darkening device 40 caused within the imaging beam path Reduction of the max. Headlight scattering angle avoided.

To be as large as possible with the imaging system 30 Variation of the scattering angle range with optimal Achieving imaging performance shows the second Lens member 32 has a refractive power that is larger or equal to twice and less than or equal to that Three times the refractive power of the first lens member 31 is.

The refractive power ratio depends on the luminance and the shape of the light-generating element, e.g. the arc of a gas discharge lamp or Filament of a light bulb, from. When used, for example a halogen incandescent lamp with 1.2 kW Power is the power ratio, which e.g. a scattering angle variation range of 3: 1 allows at 2.3. With a halogen light bulb with 2.5 kW, which is a filament with larger Has luminance, is the refractive power ratio 2.5: 1 and with a halogen incandescent lamp of 5 kW the refractive power ratio is approx. 2.8: 1. The lenses of the two lens elements have one free diameter from approx. 150 mm up to approx. 250 mm on.

Around the largest possible spread angle variation range area, i.e. the largest possible ratio of maximum scattering angle to minimum scattering angle, too achieve, it is therefore provided that the lens members 31, 32 displaceable relative to one another in this way are that both lens members are shifted to the maximum Condition as close to each other as possible are arranged. When using halogen light bulbs can the two lens members up to about 2 to Approximate 5 mm.

Since - as already mentioned above - at Gas discharge lamps not full brightness can be controlled is between the two lens members in the tube of the imaging system on one the blackout device 40, e.g. in the form of mechanical screens, such as. B. Iris diaphragms or other types of diaphragms, arranged. Through this in the tube of the Imaging system arranged darkening device 40 becomes the minimum approximation of the two lens elements limited. An approximation of the two lens elements In this case, 31, 32 is only up to approx. 30 mm possible.

Due to the large displacement path of the two lens elements 31, 32 is in connection with the refractive power distribution a special of the two lens members 31, 32 large range of scattering angles with optimal image quality enables.

The two lens elements 31, 32 can for example one or more lenses with spherical surfaces or Lenses with aspherical surfaces or also Combinations of these have.

In addition, the second lens member 32 can advantageously also one from the center to the edge the lens / lenses changing, for example have decreasing refractive power curve.

To adapt the lens elements to certain headlight tubes can the lenses of the lens limbs be rectangular or square. This Training of the headlight tube and the lenses of the Lentils takes into account the fact that the Light sources in most cases either one elongated arc or a square or have rectangular filament. Because the light source shape in the blurred area of the first lens element appears in the headlight tube as a picture and certain edge areas of a circular lens would only have a low luminance, on the other hand, the cross section of the Headlight tube should be kept as small as possible it is advantageous to use the headlight tube square or rectangular lens element to inscribe.

The two lens members 31, 32 can on the one hand manually moved against each other. But it is also possible that they shifted against each other by motor be, the motors from a control circuit can be controlled (not shown).

Claims (11)

Imaging system (30) with a variable focal length for a spotlight of stage / studio technology, comprising a first lens element (31) facing a lighting location and a second lens element (32) facing away from the lighting location and facing a light-generating element, the first and second lens elements facing each other are displaceable, as well as a combination of an iris diaphragm (33), a diaphragm slide set (35) and a gobo slide-in compartment (34) arranged in the beam path between a condenser system (20) and the second lens element (32), characterized by the features: the second lens element (32) has a refractive power that is greater than or equal to twice and less than or equal to three times the refractive power of the first lens element (31), the iris diaphragm is not arranged as the first element of the operating part to be imaged closely adjacent to the second lens element. Imaging system according to claim 1, characterized characterized in that the iris diaphragm (33) Gobo slot (34) and the Aperture slide set (35) behind the Condenser system (20) in the beam path following Arrangement: gobo slide-in compartment (34), Iris diaphragm (33), diaphragm slide set (35). Imaging system according to claim 1, characterized characterized in that the iris diaphragm (33), the Gobo slot (34) and the Aperture slide set (35) in the beam path behind the condenser system (20) following arrangement have: iris diaphragm (33), diaphragm slide set (35), gobo slot (34). Imaging system according to claim 1, characterized characterized in that on the shutter slide set (35) another storage compartment is provided in which has a replaceable iris diaphragm (33) or a gobo slide-in compartment (34) can be inserted. Imaging system according to one of Claims 1 to 4, characterized in that the magnitude of the refractive power ratio varies within one of the following intervals: greater than 2.15 and less than 2.45, in particular 2.3, greater than 2.35 and less than 2.65, in particular 2.5, greater than 2.65 and less than 2.95, in particular 2.8. Imaging system according to one of claims 1 to 5, characterized in that the first and / or the second lens element with lenses spherical surfaces. Imaging system according to one of claims 1 to 5, characterized in that the first and / or the second lens element (31, 32) lenses covered with aspherical surfaces. Imaging system according to one of the preceding Claims, characterized in that the first and / or the second lens member (32) one of the Center point changing towards the edge Has refractive index history. Imaging system according to one of the preceding Claims, characterized in that the two lens members so against each other are displaceable that the two lens members (31, 32) in the maximally shifted state very much are arranged closely adjacent to each other. Imaging system according to one of the preceding Claims, characterized in that the two lens members (31, 32) of one of a control circuit driven motor are mutually displaceable. Imaging system according to one of the preceding Claims, characterized in that the Iris from one of a control circuit controlled motor can be opened and closed.

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