DE102005035321B4 - Electronic flash unit with a zoom reflector - Google Patents

Abstract

Electron flash device with a flash tube (1) and an ellipsoidal zoom reflector containing a reflector shell (19), which is made by increasing the opening angle of its transverse mirror surfaces (5) and by reducing the distance of the flash tube (1) from its apex line from a first position for wide-angle shots ( Wide-angle position) can be brought into a second position for telephoto (tele-position), characterized in that, when changing from the wide-angle to the tele-position, the opening angle of the longitudinal mirror surfaces (18) of the reflector shell (19) also increases, so that the reflector shell (19 ) is provided with two slots (17) and the longitudinal mirror surfaces (18) between the slots (17) are made of resilient material and can be adjusted by mechanical coupling in conjunction with the transverse mirror surfaces (5) and the flash tube (1), the mechanical drive being between the Slots (17) lying on the longitudinal mirror surfaces (18) are connected to the pivotably mounted, transverse mirror surfaces (5) and the pivoting movement of the mirror surfaces (5) via a linkage (22) around a fixed pivot point (20) into a vertical movement of a slide (21 ) is convertible, which controls with its side parts (23) the opening angle of the longitudinal mirror surfaces (18) lying between the slots (17) and at the same time shifts the flash tube (1) resting on a support.

Description

The invention relates to an electronic flash device comprising a flash tube and an ellipsoidal zoom reflector incorporating a reflector cup, by increasing the aperture angle of its transverse mirror surfaces and reducing the distance of the flash tube from its apex line from a first wide-angle position to a second telephoto position (Telestellung) is brought.

From the publication DE 196 38 095 A1 is a generic electronic flash device (see 1a and 1b with description) with a flash tube (Ki) and a reflector pan-containing ellipsoidal zoom reflector obtained by increasing the aperture angle of its transverse mirror faces (HA) and reducing the distance of the flash tube from its apex line from a first wide-angle position to a second position can be brought for telephoto.

Other, beyond the generic term features are not known from this document.

From the publication US 4,821,053 A (see the 1 and 2 with description) is an electronic flash unit with zoom reflector ( 12 ), in which, at the transition from the wide-angle to the telephoto position, the opening angle of the longitudinal mirror surfaces ( 12 ). For changing the opening angle (see 3 and 4 with description) is the reflector ( 12 ) with piezoelectric material ( 26 . 28 ) by applying a voltage from a generator ( 44 ) via lines ( 34 . 36 ) to electrodes ( 30 . 32 ) the curvature of the reflector is changed. In addition, the transverse surfaces of the reflector and the distance of the flash tube from the reflector shell remain unchanged, so that this known reflector deviates greatly from the generic term.

The invention has for its object to further reduce the dimensions of an electronic flash device of the type mentioned at the same or even higher performance and to improve the optical efficiency.

This object is achieved with the features specified in claim 1.

Further advantageous embodiments of the invention are specified in the subclaims.

The advantages achieved by the invention are, in particular, that the dimensions of the electronic flash units are greatly reduced with the same power or that at the same dimensions, the power is greatly increased and the efficiency is improved.

The basic optical concept is an ellipsoidal reflector, which has the best efficiency of all reflector types, because the direct and the reflected light rays leave the reflector in the exact same angular range.

• • Vergrößern des Öffnungswinkels der längsseitigen Spiegelflächen durch Aufklappen des Reflektors an der optischen Achse, wodurch eine Verbesserung des Wirkungsgrades bei Teleausleuchtungen erreicht wird, da ein größerer Öffnungswinkel zu einer Einschnürung der vertikalen Ausleuchtung und somit zu einer Leitzahlsteigerung führt;
• • Vergrößern des Öffnungswinkels durch Aufklappen der querseitigen Spiegelflächen des Reflektors, wodurch die horizontale Lichtverteilung den entsprechenden Zoomstellungen angepasst werden kann;
• • Verschieben der Blitzröhre vor und hinter die Brennlinie des Ellipsoids, wodurch in Verbindung mit den vier veränderbaren längs- und querseitigen Spiegelflächen eine weitere Ausleuchtungs- bzw. Leistungsverbesserung erzielt werden kann;
• • Verändern des Profils einer vor der Reflektoröffnung angeordneten Fresnellinse, wodurch eine weitere Optimierung erzielt werden kann, wenn die von den Lichtstrahlen der Blitzröhre getroffenen, von der jeweiligen Zoomstellung abhängigen unterschiedlichen Bereiche der Fresnellinse den jeweiligen Erfordernissen partiell optimal angepasst sind.

The zoom effect is achieved in the present invention by simultaneously, mutually coupled changing all optical adjustment options, so that the efficiency-increasing influence of the ellipsoidal reflector can be fully utilized. Specifically, the zoom effect is achieved by changing the following optical actuators:

• Increasing the opening angle of the longitudinal mirror surfaces by unfolding the reflector on the optical axis, whereby an improvement in the efficiency is achieved in Teleausleuchtungen, as a larger opening angle leads to a constriction of the vertical illumination and thus to a Leitzahlsteigerung;
• • Increase the opening angle by unfolding the reflector's transverse mirror surfaces, which allows the horizontal light distribution to be adjusted to the corresponding zoom positions;
• • Moving the flash tube in front of and behind the focal line of the ellipsoid, which can be achieved in conjunction with the four variable longitudinal and transverse mirror surfaces, a further illumination or performance improvement;
• Changing the profile of a Fresnel lens arranged in front of the reflector opening, whereby further optimization can be achieved if the different areas of the Fresnel lens which are affected by the light beams of the flash tube are partially optimally adapted to the respective requirements.

A truly visible optical improvement occurs in particular when all the above-mentioned optical actuators can be changed simultaneously by mechanical coupling.

An embodiment of the invention is illustrated in the drawing and will be described in more detail below. Show it

1 two views or partial sections of an ellipsoidal zoom reflector with the flash tube in the wide-angle position and

2 this zoom reflector and the flash tube in the telephoto position.

The 1 shows a zoom reflector in the wide angle position. The largest possible angle range is illuminated. As end faces are two transversely extending, pivotally mounted mirror surfaces 5 arranged inwardly folded and facing each other in parallel to optimize the horizontal illumination. The flash tube 1 is shifted forward toward the reflector opening, and that from the longitudinal mirror surfaces 18 formed reflector has the smallest possible opening angle.

In 2 the telephoto position of the zoom reflector is shown. Through the rear, close to the apex line of the reflector shell lying flash tube 1 , by the enlarged opening angle of the longitudinal mirror surfaces 18 and through the outwardly pivoted transverse mirror surfaces 5 the optimal constriction of the illumination is achieved both in the horizontal and in the vertical direction.

The basis of this zoom reflector is the variability of the reflector curve by means of a flexible longitudinal reflector plate. To enable this effect is the reflector shell 19 with two slots 17 provided so that the between the slots 17 lying mirror surfaces 18 can spring.

The mechanics is a coupled system in which all necessary optical components can be adjusted with a single mechanical drive. These are here the pivotally mounted, transverse mirror surfaces 5 , the flash tube 1 and those between the slots 17 lying longitudinal mirror surfaces 18 ,

The mechanical drive is with the pivotally mounted, transverse mirror surfaces 5 connected. About a linkage 22 becomes the pivotal movement of these mirror surfaces 5 around a fixed pivot 20 in a vertical movement of a slider 21 converted the flash tube 1 moved in the vertical direction and its side parts 23 with its vertical movement, the opening angle between the slots 17 lying, longitudinal mirror surfaces 18 Taxes.

LIST OF REFERENCE NUMBERS

1

flash tube

5

transverse mirror surface

17

slot

18

longitudinal mirror surface

19

reflector cup

20

pivot point

21

pusher

22

linkage

23

side panel

Claims (3)

Electronic flash device with a flash tube ( 1 ) and a reflector shell ( 19 ellipsoidal zoom reflector obtained by increasing the opening angle of its transverse mirror surfaces ( 5 ) and by reducing the distance of the flash tube ( 1 ) can be brought from its apex line from a first position for wide-angle shots to a second position for telephoto shots, characterized in that, at the transition from the wide-angle to the telephoto position, the opening angle of the long-side mirror surfaces (FIG. 18 ) of the reflector shell ( 19 ) increases that the reflector shell ( 19 ) with two slots ( 17 ) and between the slots ( 17 ) lying longitudinal mirror surfaces ( 18 ) consist of resilient material and by mechanical coupling in conjunction with the transverse mirror surfaces ( 5 ) and the flash tube ( 1 ) are adjustable, the mechanical drive between the slots ( 17 ) lying longitudinal mirror surfaces ( 18 ) with the pivotally mounted, transverse mirror surfaces ( 5 ) and the pivoting movement of the mirror surfaces ( 5 ) via a linkage ( 22 ) around a fixed pivot point ( 20 ) in a vertical movement of a slider ( 21 ) is convertible, with its side parts ( 23 ) the opening angle between the slots ( 17 ), longitudinal mirror surfaces ( 18 ) and at the same time the flash tube ( 1 ) shifts. Electronic flash device according to claim 1, characterized in that before the opening of the reflector shell ( 2 . 19 ) a Fresnel lens is arranged, whereby the light rays of the flash tube ( 1 ), depending on the respective zoom position different areas of the Fresnel lens are partially optimally adapted to the respective requirements. Electronic flash device according to claim 2, characterized in that the optimum adjustment of the Fresnel lens by changing the partial Fresnel structure and / or by additional prism structures on the back of the Fresnel lens.

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