Abstract:
A device with a camera unit, and an operational procedure for the device, where the device has a lens for taking pictures of the area outside of a motor vehicle and a cover unit that can change by means of a drive from a closed position to an open position and vice versa, where the cover unit covers the lens of the camera unit in the closed position and uncovers the lens in the open position making it possible to take a picture, and where the cover unit has a lens cover that is movable on one side by means of a bearing shaft on the device.

Description:
TECHNICAL FIELD 
     The disclosure concerns a device with a camera unit that has a lens for taking pictures of the area outside of a motor vehicle and a cover unit that can change by means of a drive from a closed position I to an open position II and vice versa, where the cover unit covers the lens of the camera unit in the closed position I and uncovers the lens in the open position II making it possible to take a picture, and where the cover unit has a lens cover that is movable on one side by means of a bearing shaft on the device. 
     BACKGROUND 
     Such types of devices serve for the retention and protection of the camera unit so that it is protected from environmental influences outside the motor vehicle. Numerous embodiment variants exist in which the camera unit is arranged in the device, e.g. even swiveling, and the cover can change additionally or by the camera unit from its closed position to its open position. 
     In the following we will not distinguish between the objective and the lens of a camera unit. Rather, the two concepts should be understood as synonymous even if clear technical differences exist. 
     As an example, document DE 699 18 032 T2 is known from the prior art, in which a closing mechanism is able to close the lens of the camera unit by a turning and swiveling motion. For this purpose the lens cover is connected on the left and right with a turn plate that has an eccentric shaft. Consequently, the lens cover is driven to the left and right side by the corresponding closing mechanism. This closing mechanism has a complex construction for which there must be appropriate space. 
     From another document, DE 60 2004 003 255 T2, a rear-view device for a motor vehicle is known, wherein the lens of the camera is likewise closed by a lens cover. This is pulled over the lens of the objective in the form of an arch. The lens cover is operated for this purpose by only a jointed arm. This device has the disadvantage, however, that the objective or the lens of the objective can be easily scratched by the inside of the lens cover if dirt gets between these two parts. This operating mechanism also has a complex construction. 
     BRIEF SUMMARY 
     The disclosure provides a device of the above-mentioned type that has a simple and solid construction. Also to the disclosure treats the lens carefully when changing from a closed position to an open position and vice versa. 
     The disclosure provides that the lens cover is mounted so as to shift longitudinally and to rotate. Since the lens cover and the bearing shaft together form the cover unit, the lens cover is mounted so as to shift longitudinally and rotate through the bearing shaft itself. For this it is advantageous if the lens cover is constructed in one piece and/or as a material unit with the bearing shaft. In order to treat the lens securely and lightly as much as possible, the lens cover is first shifted laterally a minimum distance a from the lens and is then turned away at a predefined angle α, in order to clear the shooting area of the camera. The lateral shifting of the lens cover from its closed position I to an intermediate position III takes place essentially in the direction of the shooting of the camera. As the lens cover in this intermediate position III still looms in the shooting area of the camera unit, it must be turned out of this shooting area in order to enable picture taking outside of the motor vehicle. Optionally it is conceivable for the lens cover to be pulled opposite the direction of shooting on the device in order to enable the largest possible wide-angled shooting area for the camera unit. 
     As was already mentioned above, it can be provided that the lens cover is arranged rigidly on the bearing shaft. In this case it is conceivable for the lens cover to be connected tightly to the bearing shaft by means of a notch or screw connection. Thus, the lens cover can be arranged in essence orthogonally at a front end of the bearing shaft. The intention is that a fictively spread out surface of the lens cover is aligned in essence orthogonally to the axis of rotation of the bearing shaft. The cover unit then has an essentially L-shaped form wherein the vertical part of the “L” is formed by the bearing shaft and the horizontal part of the “L” is formed by the lens cover. Consequently, the cover unit itself is designed to be simple in construction. The whole cover unit can be in one piece and/or materially unified, however it is also conceivable for the bearing shaft to be made of a different material from the lens cover. Preferably, at least the lens cover is constructed from a corrosion resistant material, such as stainless steel, aluminum or plastic. 
     It is also conceivable for the lens cover to be movable from the closed position I first essentially in the shooting direction of the camera unit and then turned away. For this purpose the bearing shaft can first be made to shift axially in a guide sleeve, which is arranged on the device itself, and then the bearing shaft can be made to turn about a predefined angle α. As a result of this, the lens cover is first lifted or spaced at a minimum distance a from the objective or lens of the camera unit. By this process the lens cover can be removed safely from the objective without affecting or scratching the lens. The lens cover itself can have an opening for the objective or lens so that the lens cover does not touch the lens itself even in the closed position I. It is also conceivable for a cloth or cleaning element to be provided on an inner surface of the lens cover, which is directed toward the lens, so that it comes into contact lightly and with a cleaning function with the lens when the lens cover is securely in the closed position I. Basically at least one seal should be provided between the camera unit and cover unit, so that the lens cover in the closed position protects the lens even from sprayed water and the like. It is also conceivable for the seal between the lens cover and the camera unit to be fashioned as a labyrinth seal. Since the lens cover is shifted laterally at a parallel minimum distance a from the lens, the lens cover can then be turned at an angle α, so the lens cover itself does not loom in the shooting area of the camera unit. Further, it is conceivable for the lens cover to then be drawn in the opposite direction from the shooting direction, toward the camera unit, thereby reducing the previously resulting minimum distance a. It can thereby be ensured that the lens cover will not interfere with picture taking even with a very wide-angled shooting area. Additionally, the lens cover can stop at an opened position where it is situated in a secured position in which it is protected from mechanical influences as much as possible. For this purpose the device can provide a receiver or opening for the lens cover in its opened position II. 
     In order to enable the above-described movement of the lens cover, a slide guide can be provided on the back end of the bearing shaft opposite the lens cover, by which a defined change (as described above) can be executed from the closed position I to the opened position II and vice versa. This slide guide thus serves on one hand for the lateral shifting of the lens cover and on the other hand for the subsequent turning and the optional reverse lateral shifting of the lens cover. Of course, it is also conceivable for an adjusting mechanism that operates the lens cover in the desired manner to be provided in place of the slide guide. The slide guide, however, has an advantage over the adjusting mechanism since it has a simple construction and is reliable. 
     The above-mentioned slide guide can have at least one slide block on the bearing shaft as well as a first slide track on the guide sleeve, by which the slide block acts together with the first slide track in a form-fit manner. The slide block can be fashioned on the one hand as a cylindrical peg that is arranged in a hole, particularly in the form of a blind hole on the back end of the bearing shaft. This construction enables a simple assembly of the device of the invention, particularly the lens cover, since the cylindrical peg can be installed just after the pre-assembly of the cover unit on the device. Preferably, the cylindrical peg is clamped in the hole of the bearing shaft by a tight fit. On the other hand, it is conceivable for the slide block to be formed by a cylindrical cam that is arranged directly on the bearing shaft. Since the slide block is required for the operation of the cover unit, this must be tightly connected to the bearing shaft, wherein the slide block can be sprayed or cast on, for example. 
     At the back end of the bearing shaft a carrier, particularly in form of a lever, can attach, by which the cover unit itself can be driven in order to enable the desired sequence of motions. This carrier serves as a mechanical connecting piece between the drive and the cover unit. The drive may be an actuator, for example, particularly a linear actuator or a rotary actuator which engages directly or indirectly with the carrier via a bar, a Bowden cable, a gear wheel or a mechanical system. Since the carrier itself need only be swiveled or turned in a circle, a simple construction is likewise possible. If a bar or Bowden cable is used as the connector between the drive and the carrier, it is conceivable to fashion the drive detached as an additional part for the device of the invention. The options for deployment within a limited space can thereby be expanded. It is also conceivable to fall back on drives already existing in the motor vehicle, which could then serve additionally as a drive for the device or cover unit as well. 
     In the carrier a further, second slide track can be arranged, which also cooperates in a form-fit manner with the above-mentioned slide block on the bearing shaft, wherein, in particular, the carrier with a cylindrical section comprises the back end of the bearing shaft and the guide sleeve with the first slide track. Thus, the slide guide mentioned is formed by the slide block on the bearing shaft and the first slide track on the guide sleeve and the second slide track on the carrier. By this interaction of the parts of the slide guide the desired sequence of motions for the lens cover can be easily and securely realized. In this case, no other parts, e.g. spring elements or gear wheels, notches of the like, are required. To enable the carrier to activate the cover unit, it is provided that the carrier is arranged to be rotatable and axially immovable along the longitudinal axis of the bearing shaft on a rear section of the guide sleeve. For this purpose the carrier can be axially secured by a securing element, e.g. a snap ring or a retaining ring, on the rear section of the bearing shaft. Consequently, although the carrier is flexible in turning to the guide sleeve it is not laterally shiftable. Instead, a turning motion of the carrier is converted by the slide guide into a lateral shifting or turning motion of the lens cover or cover unit itself. The rear section of the guide sleeve can have a smaller outer diameter than the remaining outer diameter of the guide sleeve. The carrier itself can also have a cylindrical section with which it is set on the rear section of the guide sleeve. On the cylindrical section of the carrier a lever-shaped extension can be attached, on which the drive for the lens cover can engage. 
     In what follows, the principle of the slide guide will be described in greater detail. The cover unit is rotatable and laterally shiftable in the guide sleeve, for which purpose the guide sleeve has a continuous inside diameter that is somewhat larger than the outer diameter of the bearing shaft so that there is some play and smoothness in its placement in the guide sleeve. In order to provide the concrete sequence of motions for the cover unit, the first slide track is provided in the rear section of the guide sleeve. In the present case this made in the shape of a “U”, by which it is clear that the lens cover is first shifted laterally without turning and is then turned without a lateral shift and then shifted toward the device without turning. In this, the vertical sides of the “U” serve to shift the lens cover laterally and the horizontal side of the “U”-shaped first slide track is used exclusively to turn the lens cover of the cover unit. Of course, a corresponding sequence of motions for the lens cover can be realized by another shape of the first slide guide. The cover unit itself is guided in the first slide track in a form-fit connection by means of the slide block. Thus, the first slide track does not allow any other sequence of motions for the lens cover. For an actual movement of the lens cover or cover unit to take place, the slide block looms out of the first slide track into the second slide track in the carrier. As a result, the second slide track in the carrier serves to guide the cover unit through the first slide track with the slide block. For this purpose, the second slide track can be made essentially V-shaped and has wedge-shaped or triangle-shaped sections to enable a raising of the slide block in the U-shaped first slide track, particularly in the vertical sections or flanks. The corresponding slide block is guided through the first slide track from the second slide track by an inner as well as an outer opening edge. It is also conceivable in another variant of the invention for the cover unit to be spring loaded axially in the guide sleeve, wherein the available spring force pushes the cover unit in the shooting direction of the camera. In this variant an inner, particularly V-shaped, opening edge can be dispensed with, as the spring force pushes the cover unit permanently in the shooting direction of the camera. Consequently, the outer opening edge acts against the spring force and pushes the cover unit back toward the device. 
     It can further be provided in the device of the invention that the camera unit is held immovable on or in the device and the cover unit is held movably beside the camera unit. Thus, only the cover unit or lens cover changes its position with the change from closed position I to opened position II. Since the device itself is arranged in an opening in the outer wall of the motor vehicle, especially on a part of the body, the device should close this opening, especially making it water-tight. For this purpose the device has a partition that separates the outside of the motor vehicle from the inside, wherein the camera unit and the cover unit extend through the partition so that both the camera unit and the cover unit are in direct contact with the outside of the motor vehicle. The entire device can be protected from further influences by an additional housing in the inner area or on the inside of the partition. The camera unit itself can be held on the partition by means of a mechanical receiver, wherein the receiver and/or guide sleeve, in particular, can be made in one piece and/or materially uniform with the partition. On the partition itself notches or retainers can be provided for fastening it in the opening of the motor vehicle. It is also conceivable for the drive to comprise an activating unit for opening and/or closing a lid on the motor vehicle, wherein the activating unit has at least one manually operable activating element. This activating element can be, for example, a mechanical or electric sensor, switch or lever. The activating element itself can also be arranged to be pushed through the partition so that it is operable from the outer area of the motor vehicle. 
     The camera unit itself can be held form-fit in the receiver by an additional holding means, such as a clip or a clamp. It is also conceivable for the guide sleeve to be connected to the partition by threading, so that a two or more part version of these parts is feasibly realized. 
     It is also a problem of the device of the disclosure to provide a corresponding activating method for a device with a camera unit in accordance with the overriding concept of claim  13 , which will enable a secure and reliable operation of the lens cover in a simple manner. 
     To solve this problem, a method having the features of claim  13 , especially from the characterizing portion, is proposed. 
     The invention thus provides that the method carries out the following steps in order to transfer the lens cover from the closed position I to the opened position II:
         a) the lens cover is shifted laterally in the shooting direction at a minimum distance   b) then the lens cover is turned away at a predefined angle α in order to clear the lens.   We would note for step a) that the lens cover is moved in essence parallel to the lens by the lateral shift in order to avoid damaging the objective or lens by the movement of the lens cover. It is also conceivable for step b) to be executed simultaneously after the start of step a), wherein step a) must first lift the lens cover safely from the lens. With this combined simultaneous motion of step a) and b) a shorter amount of time for the change between the closed position and the opened position can be achieved.       

     Further advantageous embodiments of the method of activation for a device with a camera unit are presented in the dependent method claims. 
     For instance, it is conceivable for the following step to be carried out after step b):
         c) the lens cover is shifted laterally or drawn against the shooting direction toward the device.       

     In this manner, the shooting area of the lens can be enlarged since the lens cover is more tightly arranged on the device in its opened position. It is also conceivable for the lens cover to be immovable in relation to the bearing shaft and exclusively operated by it during the change from the closed position I to the opened position II and vice versa. As a result, the lens cover has no relative movement to the bearing shaft so that the lens cover and the bearing shaft can form the cover unit themselves. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages, features and details of the invention emerge from the following specifications in which two exemplary embodiments of the invention are described in detail with reference to the drawings. The technical features mentioned in the claims and the specification can give the essence of the invention either separately or in any combination. The drawings are: 
         FIG. 1  three-dimensional view of the device of the invention in a closed position I, 
         FIG. 2  section of the device of the invention from  FIG. 1 , wherein a cover unit is shifted laterally in an intermediate position III, 
         FIG. 3  comparable section from  FIG. 2 , wherein the cover unit is now turned at an angle, 
         FIG. 4  comparable section from  FIG. 3 , wherein the cover unit is now pulled toward the shooting direction on the device, 
         FIG. 5  three-dimensional blow-up of the device of the invention, 
         FIG. 6   a  three-dimensional view of the mechanical interaction of the cover unit with the guide sleeve and a carrier in the closed position I, 
         FIG. 6   b  comparable to  FIG. 6   a  but with the cover unit in an intermediate position III and 
         FIG. 6   c  comparable to  FIGS. 6   a  and  b , wherein the cover unit is in the opened position II. 
     
    
    
     DETAILED DESCRIPTION 
     In  FIG. 1  a first embodiment of the device  10  of the invention is represented in a three-dimensional view. Herein the device  10  is shown mainly from the point of view of the outside of a vehicle, which can be a motor vehicle. The device  10  itself comprises a camera unit  12  that is fixed in a receiver  17  by a clip-like holding means  17 . 1  on the device  10  in a form-fit manner. From the camera unit  11  an electrical cable extends (in the present case upward to the left) over a connector  11 . 3 . In  FIG. 1  the lens  11 . 1  of the camera unit  11  is not visible as it is hidden by a cover unit  12 , particularly a lens cover  12 . 1 , which is in the closed position I. The cover unit  12  itself is arranged next to the camera unit  11  (here to the left). The cover unit  12  is mounted or received in the device  10  so as to be rotatable or laterally shiftable by means of a guide sleeve  13 . In the present case, the guide sleeve  13  is fashioned in one piece with the partition  10 . 1  of the device  10  exactly like receiver  17 . Preferably, this kind of partition  10 . 1  is made of injection-molded plastic. The whole device  10  is placed on a motor vehicle in an opening, particularly in a part of the body, and closes this opening. For this purpose a sealing groove  10 . 5  is provided on the inside  10 . 3  of the partition  10 . 1  in which a seal  10 . 7  can be placed. The opening in the vehicle is closed by this seal  10 . 7  against outside environmental influences, i.e. protected from water and dirt. The camera unit  11  and the cover unit  12  extend through the partition  10  in such a way that the lens  11 . 1  and the lens cover  12 . 1  are arranged in the outer area of the device  10 , whereas the camera body  11 . 2  and the remaining part of the cover unit  12 , which also includes the bearing shaft  12 . 2 , are located in the inner area of the device  10 . On the outside  10 . 2  of the partition  10 . 1 —in the present case—there is an activating unit  18  (right) beside the camera unit  11 . The activating unit  18  itself has a meshing hollow that is formed in the partition  10 . 1  in order to access a manually operable activation element of the activating unit  18  from the outside. The whole device  10  can be locked and held in the opening in the vehicle via notch means  10 . 4  that are arranged on the inside  10 . 3  of the device  10 . 
     The device  10  can be sealed off on the inside  10 . 3  of the partition  10 . 1  with an optional housing  10 . 6 . In  FIG. 1  this housing  10 . 6  is represented by a hatched in extension. 
     So that the camera unit  11  can be used to take pictures, the cover unit  12  or the lens cover  12 . 1  must be transferred from its closed position I to an opened position II, particularly via an intermediate position III. For this purpose a carrier  15  is arranged on the rear end  12 . 3  of the cover unit  12 , which ensures the operation of the lens cover  12 . 1 . The change of the lens cover  12 . 1  from its closed position I to its opened position II is represented and described in more detail in  FIGS. 2 to 4 . 
     A section from  FIG. 1  is shown in  FIG. 2 , wherein in this case the cover unit  12  essential to the invention is visible. In contrast to  FIG. 1  the carrier  15  is turned clockwise about the longitudinal axis  12 . 2 ′ of the bearing shaft  12 . 2 . This results in a lateral movement  19  of the whole cover unit  12  in the shooting direction  11 . 5  of the camera unit  11 . By this lateral movement  19  the lens cover  12 . 1  is lifted at a parallel minimum distance a from the lens  11 . 1 . The required movement for this is produced by a slide guide  14 . Thus, the turning motion of the carrier  15  is converted into a lifting motion or lateral shifting of the cover unit  12 . For this purpose, a second slide track  15 . 1  is arranged in a cylindrical section  15 . 2  in the carrier  15 . In this second slide track  15 . 1  a slide block  12 . 6  looms, which is fastened tightly with the bearing shaft  12 . 2 , particularly on a rear end  12 . 3  of the bearing shaft  12 . 2 . The slide block  12 . 6 , in the present case, comprises a cylindrical peg  12 . 6  that is arranged in a radial hole  12 . 5  in the bearing shaft  12 . 2 . The hole  12 . 5 , in the present case, comprises a blind hole that does not fully radially pass through the bearing shaft  12 . 2 . Thus, the peg  12 . 5  extends only on one side radially out of the bearing shaft  12 . 2  in order to interact in a form-fitting fashion with a first slide track  13 . 1  in the guide sleeve  13  and a second slide track  15 . 1  in the carrier  15 . The first slide track  13 . 1  is not represented in  FIGS. 1 to 4  since this is more or less completely covered by the carrier  15 , particularly the cylindrical section  15 . 2 . The carrier  15  sits with its cylindrical section  15 . 2  rotatable on a back section  13 . 2  of the guide sleeve  13 , however the carrier  15  itself is axially secured on the guide sleeve  13 . In the present case, the back section  13 . 2  of the guide sleeve  13  is tapered for this reason in order thus to accommodate the carrier  15 . The carrier  15  has a lever-shaped attachment  15 . 3  beside its cylindrical section  15 . 2 , by which it interacts mechanically, directly or indirectly, with a drive  16 , which is schematically represented in  FIG. 5 . The carrier  15  is turned on the back section  13 . 2  of the guide sleeve  13  by this lever-shaped attachment  15 . 3 . This turning motion is converted to the sequence of motions of the cover unit  12  by the slide guide  14 . 
     In  FIG. 3 , which corresponds essentially to  FIG. 2 , the lens cover  12 . 1  is additionally turned about an angle α. Thus, the objective  11 . 1  or lens  11 . 1  of the camera unit  11  is now also visible. The carrier  15  has been turned further clockwise for this purpose in order to turn the lens cover  12 . 1  in its pulled out position about the angle α  21 . The actual sequence of motions for the cover unit  12  is provided by the first slide track  13 . 1 , which is represented in more detail in  FIGS. 6   a  to  6   c . This first slide track is made in the form of a “U” so that the cover unit  12  is first laterally shifted, then enables a turn about the predefined angle α  21  and is finally pulled back, i.e. opposite the shooting direction  11 . 5 , in order to reach the desired opened position II. In  FIG. 3 , however, the lens cover  12 . 1  is still represented in an intermediate position III. So that the slide block  12 . 6  of the provided first slide track  13 . 1  can follow, this is shifted through the second slide track  15 . 1  in the carrier  15 . This serves to allow an inner edge  15 . 1 ′ of the second slide track  15 . 1  to lift or shift laterally the cover unit  12  in the shooting direction  11 . 5 , while an outer edge  15 . 1 ″ of the second slide track  15 . 1  serves to allow the turning  20  of the cover unit  12  and the lowering of the cover unit  12  in the direction opposite the shooting direction  11 . 5 . Both the inner and outer edges  15 . 1 ′,  15 . 1 ″ are made essentially to be in the shape of a “V”. This configuration of the second slide track  15 . 1  makes it possible to dispense with a spring element for the lateral shifting of the lens cover  12 . 1  or cover unit  12 . In  FIGS. 6   a  to  6   c  the second slide track  15 . 1  is formed differently since a corresponding spring element is used. 
     In  FIG. 4  the comparable section from  FIGS. 2 and 3  is shown again, however here the lens cover  12 . 1  has reached its closed position II. In this closed position II the lens cover  12 . 1  is drawn toward the device  10  and thus in the opposite direction to the shooting direction  11 . 5  and so the minimum distance a, previously produced by the lateral lift of the cover unit  12 , is again reduced. It is also conceivable for the lens cover  12 . 1  to be arranged in a receiver inside the device  10  in a park position. In the opened position  2  represented here, a large or wide-angle shooting area  11 . 4  is possible for the camera unit  11 . The carrier  15  has reached a maximum displacement in the opened position II so that the slide block  12 . 6  is now arranged on the edge of the lever-shaped attachment  15 . 3  in the second slide track  15 . 1 . In order to move the lens cover  12 . 1  out of its opened position II into its closed position I, the slide block  12 . 6  on the inner edge  15 . 1 ′ of the slide track  15 . 1  is pushed high in the vertical section or side of the U-shaped first slide track  13 . 1 . Finally the reverse sequence of motions, as already described above, takes place until the lens cover  12 . 1  reaches its closed position I again. 
     In  FIG. 5  the device  10  of the invention is represented in a three-dimensional blow-up. As is apparent, the camera unit  11  as an independent part is not yet fixed in the receiver  17  provided on the device  10 . Likewise, the cover unit  12  is not yet placed in the guide sleeve  13  and connected with the carrier  15 . As is clear from  FIG. 5 , the cover unit  12  has an L-shaped formation. The vertical section of the “L” is formed by the bearing shaft  12 . 2 , to which the lens cover  12 . 1  is connected as the horizontal section of the “L” on the front end  12 . 4 . The bearing shaft  12 . 2  can be made in one piece with the lens cover  12 . 1 . It is also conceivable for the bearing shaft  12 . 2  to be, for example, screwed into the lens cover  12 . 1  as a separate part. On the rear end  12 . 3  of the bearing shaft  12 . 2  the slide block  12 . 6  is arranged in a radial protrusion. This slide block  12 . 6 , in the present case, comprises a peg  12 . 6  that is embedded in a hole  12 . 5  in the bearing shaft  12 . 2 . The hole  12 . 5  itself need not penetrate the bearing shaft  12 . 2  completely. The peg  12 . 6  is fixed in the hole  12 . 5  so as to be as captive as possible, e.g. by a driving fit or by a glue or screw connection. Preferably the peg  12 . 6  is installed in the guide sleeve  13  only after a premounting of the cover unit  12 . Then the carrier  15  with its cylindrical section  15 . 2  can also be premounted ahead of time across the back section  13 . 2  of the guide sleeve  13 . 
     In  FIGS. 6   a  to  6   c  the mechanical interaction of the slide block  12 . 6  with the first slide track  13 . 1  and the second slide track  15 . 1 , which together form the slide guide  14 , is represented. In  FIG. 6   a  the opened position I of the cover unit  12  is represented. In the embodiment variant from  FIGS. 6   a  to  6   c  the cover unit  12  is axially spring-loaded. Thus the spring element, which is not pictured, pushes the bearing shaft  12 . 2  axially out of the device  10  into the shooting direction  11 . 5 . Consequently the slide block  12 . 6  is steadily engaged to go as far as possible in the shooting direction  11 . 5 , i.e. downwards in the present case. In  FIG. 6   a  first the slide block  12 . 6  lies above in the left vertical section of the U-shaped first slide track  13 . 1 . In this, the slide block  12 . 6  can touch the upper end of the first slide track  13 . 1 , since this is pushed by the second slide track  15 . 1  against the spring action. If the carrier  15  is now turned clockwise by its lever-shaped attachment  15 . 3 , then the slide block  12 . 6  follows the outer edge  15 . 1 ″ of the second slide track  15 . 1  because of the present spring action. Thus the slide block  12 . 6  also passes through the left vertical section of the U-shaped first slide track  13 . 1 , resulting in a lateral shift  19  of the cover unit  12 . In spite of the turning of the carrier  15 , however, the lens cover  12 . 1  is not yet turned since the slide block  12 . 6  first must reach the horizontal section of the “U” of the first slide track  13 . 1 . 
     In  FIG. 6   b  the intermediate position III of the lens cover  12 . 1  or cover unit  12  is represented. In this intermediate position III the lens cover  12 . 1  has already been turned nearly half of the angle α  21 , which means that the slide block  12 . 6  has passed through half of the horizontal section of the U-shaped first slide track  13 . 1 . So that the cover unit  12  can be turned the full angle α, the left flank of the V-shaped outer edge  15 . 1 ″ of the second slide track  15 . 1  now pushes the slide block  12 . 6  to the right in the horizontal section of the U-shaped slide track  13 . 1 . As soon as the slide block  12 . 6  hits the right edge of the U-shaped slide track  13 . 1 , further turning of the cover unit  12  is no longer possible. In this position the lens cover  12 . 1  can only still be pulled opposite the shooting direction  11 . 5  toward the device  10 . In this case as well, the left outer edge  15 . 1 ″ of the V-shaped second slide track  15 . 1  serves to guide the slide block  12 . 6  inside the right vertical U-shaped section of the first slide track  13 . 1 . 
     In  FIG. 6   c  the lens cover  12 . 1  is represented in its opened position II. In this case the lens cover  12 . 1  has been guided toward the device  10  opposite the shooting direction  11 . 5  by the right vertical guide flank of the U-shaped first slide track  13 . 1 . So that the slide block  12 . 6  will pass through the right vertical guide flank against the spring action, it is pushed by the second slide track  15 . 1 . The left V-shaped section of the outer edge  15 . 1 ″ then ensures the corresponding movement of the slide block  12 . 6 . 
     At this point it should be mentioned that the upper end of the U-shaped first slide track  13 . 1  must not end at the same height, whereby an axial distance of the lens cover  12 . 1  is present from its closed position I to the opened position II. In  FIG. 6   b  the inner edge  15 . 1 ′ for the second slide track  15 . 1  is also indicated by hatch marks and serves to push the slide block  12 . 6  in the shooting direction  11 . 5 , if no spring element is provided for this purpose. It is also conceivable to design a combination for an embodiment and provide the spring element as well as the inner edge  15 . 1 ′ of the second slide track  15 . 1  for the lateral shift  19  of the bearing shaft  12 . 2  or the cover unit  12 . In addition, other combinations of the above-described features can be designed as long as these are not mutually exclusive.