FR2562680A1 - Combined lens cap and sun shield - Google Patents

Abstract

The invention relates to photographic accessories of the lens cap and sun shield type which protect the lens system against any damage from outside and against unwanted illumination when taking photographs. The device consists of a ring 1 which fits on to the front of the lens. Spindles 2 are attached to the ring and carry thin hinged plates 3. The plates cover the ring completely when they are closed and are opened instantaneously by resilient return means 4, the opening being limited by a control system 5. Depending on the focal length used, the device is held in a closed position by one or more catches 6. The invention is particularly applicable to movie cameras.

Description

 The present invention relates to a lens cover system combined with variable inclination, for a camera more particularly.

 Currently, there are several kinds of lens covers, essentially differing from each other by their method of attachment to the shooting lens.

 These front plugs can sometimes appear on certain sun visors, the two elements however remaining clearly dissociated. However, such an addition is not possible with metal sun visors.

Likewise, there are at present many models of sun visors different by their construction structure, as well as by their opening angle, in general two (normal and wide-angle), sometimes more.

For practical and economic reasons, it seems difficult to widen the range of openings offered beyond two or even three models for a given lens diameter. This explains why for certain focal lengths of lenses of given brands, it is practically impossible to find the corresponding lens hood. The problem most often posed by current lens hoods is that in many cases they cannot receive a lens cover. I1 results in a number of tedious maneuvers, which consist, when one wants to cover the lens, to remove beforehand the sun visor.

 The system according to the invention overcomes these drawbacks by coupling the role of plug to that of sun visor. In addition, the system is equipped with a device for adjusting the opening angle of the sun visor. In fact, the system can be presented in two aspects: in the closed position it then appears according to its lens cover cap shape, or in the open position where it has become a sun visor.

 The device according to the invention consists of a series of lamellae independent of each other, fixed on axes arranged around a fixed or movable screwed or clipped ring, adaptable to the diameter of the objective.

 The opening of the sun visor is instantaneous due to the presence of elastic return means. Once folded, the slats are held in position by a closing device comprising one or more tabs.

 According to a preferred embodiment, the system for adjusting the opening angle of the slats consists of a set of rotary polyhedral stops placed on the periphery of the ring. According to a variant, the means for adjusting the opening is a set of two symmetrical stop screws.

 The invention will be better understood with the aid of the following description of the appended drawings, given by way of exemplary embodiments.

 Figure I shows the device according to the invention open face.

 FIG. 2 shows the device according to the invention from the closed side.

 Figure 3 shows the same device in section according to its preferred embodiment.

 Figure 4 shows in detail the ratio of a stop with the strip in the open position.

 In Figure 1, the blades (3) are fixed to the ring (1). Elastic return means (4) exert on them a centrifugal force.

 The two upper strips come to bear on adjustable stops (5). The tabs (6) are fixed on the same strips and allow the system to be kept in the closed position.

 In Figure 2, the strips (3) are folded and held in position thanks to the presence of the tabs (6).

The adjustable stops (5) are fixed on the support ring (1). The system is thus presented in the closed position
In FIG. 3, the lamellae (3) have pivoted about their axis (2), in the lens cover position. The stops (5) fixed on the support ring (1) are free.

 When the cleats (6) are moved, the slats (3), under the impulse of the elastic return means, pivot around their axis (2) and come to bear on. the adjustable stops (5), fixed on the support ring (1).

 In Figure 4, the strip (3) having pivoted on its axis (2), comes to bear on the adjustable stop (5).

 The device which is the subject of the invention can be used both as a lens cover, as a protector for the optical lens, as well as as a sunshade which protects the photographic impression against unwanted radiation, regardless of the focal length of the lens.

 It can be used in the photographic, cinematographic video field, as well as any optical system claiming the aforementioned protections.

Claims (6)

 1. Accessory for camera, intended to constitute both lens cover and sun visor, characterized in that it is composed; a fixed or movable screwing or clipped ring adaptable to the diameter of the objective, on which are provided fastening systems for axes around which lamellas pivot.  Said strips in the closed position cover an area equal to that of the ring and constitute a sun visor, from the instantaneous opening of the system, which is ensured by elastic return means arranged at the axes.  2. Accessory according to claim I characterized in that it comprises means making it possible to adapt the angle of opening of the strips to the angle of optical coverage of the objective.  3. Accessory according to claim 2 characterized in that said means consist of a system of adjustable stops.  4. Accessory according to claim 3 characterized in that the adjustable stops are poly axes.  5. Accessory according to claim 3 characterized in that the adjustable stops are screws.  6. Accessory according to claim I characterized in that it comprises one or more cleats making it possible to maintain the system in the closed position.