Camera with movable optical albada viewfinder

The photographic camera has an optical direct viewfinder based on the inverse Galilean optical principle. The direct viewfinder is vertically extendible out of the camera body relative to the optical axis of the camera and is retractable back into the body. The direct viewfinder is designed as a one-piece U-shaped component enclosing the camera body and guided therein, with integrated front lens and integrated eyepiece lens. The extension movement is preferably effected by a compression spring exerting a corresponding force on the direct viewfinder.

FIELD OF THE INVENTION 
The invention relates to a photographic camera having an optical direct 
viewfinder, based on the inverse Galilean optical principle, that is 
extendible out of the camera body vertically to the optical axis of the 
camera and is retractable back into the body. 
BACKGROUND OF THE INVENTION 
Rigid or folding albada viewfinders are known mainly in underwater cameras, 
however these viewfinders are provided only as a frame and without optical 
elements. In addition, there are design examples in which the viewfinder 
is movably accommodated in one part of the camera. This is achieved with 
considerable technical effort, but without achieving the requirements of 
an albada viewfinder. The viewfinders are usually inadequately 
dimensioned. When the viewfinders are made large in size, they then cannot 
be integrated into the required camera design in a space-saving manner. 
Cameras are known from the prior art in which the viewfinder is 
accommodated inside the body when the camera is not in use. 
German Patent 1 170 240 describes a photographic camera having a direct 
viewfinder based on the inverse Galilean optical principle. The viewfinder 
is mounted on the upper narrow side of the camera. The viewfinder front 
lens frame is provided with a slide that penetrates into the camera when 
the viewfinder is folded in. The viewfinder folding mechanism has a lens 
fitted in the frame on the front of the camera that is guided on the 
inside and is connected to a slide that effects covering of the camera 
lens when the viewfinder is pushed together. The front lens frame is 
rigidly connected to a cover whose rear end is connected to the eye lens 
mounting by hinged struts. The eye lens mounting is pivotably mounted on 
the top of the camera by a hinge and folds down flat thereon. The cover is 
flush with the body when folded together. 
German utility model 7 625 869 discloses a viewfinder camera with a movable 
viewfinder. The camera is equipped with a covering cap which is movable 
transversely to the optical axis of the camera and includes a viewfinder 
lens and a viewfinder eyepiece. In the extended position, the viewfinder 
(lens and eyepiece) are each free to be looked through. In the retracted 
position of the cap, the viewfinder lens projects from the front of the 
camera while the viewfinder eyepiece finds space between the cover and the 
camera side. 
German patent 2 362 429 discloses a photographic camera of flat design 
having a body section extendible and retractable in the longitudinal 
direction of the camera body and equipped with a cover matched to the 
cross-section of the camera body, and in which the body section releases 
an optical direct viewfinder in the extended state and in the retracted 
state is flush with the camera body and inside the latter. 
SUMMARY OF THE INVENTION 
The object underlying the present invention is to create a camera having a 
movable optical albada viewfinder that is adequately dimensioned and that 
can be accommodated inside the camera in a space-saving manner. In 
addition, the camera should be of simple design and inexpensive 
manufacture. 
This is achieved in accordance with the invention in that the direct 
viewfinder is designed as a one-piece U-shaped component enclosing the 
camera body and guided therein, with integrated front lens and integrated 
eyepiece lens. 
The advantage of the device in accordance with the invention is that the 
direct viewfinder of the camera is made in one piece, and that in the 
retracted position the direct viewfinder is flush with the outer contour 
of the camera. The handling or extension of the direct viewfinder is 
simple and is achieved by operating the film transport lever. This pulls 
back a retaining nose provided on the film transport lever and engaging in 
a recess provided on the direct viewfinder in the retracted state. The 
direct viewfinder is designed U-shaped, with the sides of the "U" being 
spaced such that the direct viewfinder encloses the camera body and is 
therefore movable back and forth, vertically to the optical axis, from a 
retracted position to an extended one. The movement for extending the 
viewfinder is initiated by a compression spring surrounding a guide rod 
connected to the direct viewfinder. 
Further advantageous embodiments of the invention are shown in the 
sub-claims.

DETAILS OF THE INVENTION 
The camera comprises a camera body 3 enclosed by a from shell 1 (see FIG. 
1) and a rear wall 2 (see FIG. 3). On the camera body 3 is a direct 
viewfinder 4 having a U-shaped design such that it extends around the 
camera body 3 (shown in a dotted line). The camera body 3 has an upper 
recess 3a adjacent to a front recess 3d. The recesses 3a and 3d receive 
the direct viewfinder 4 in the retracted position such that it is flush 
with the outer contour of the camera formed from the front shell 1 and the 
rear wall 2. The direct viewfinder 4 comprises a transparent and clear 
material, preferably plastic. A front lens 8 and an eyepiece lens 9 are 
integral in one piece with the direct view finder 4. Similarly, a flash 
window 12 is provided in the front shell 1. A circuit such as is commonly 
known (shown by thick line) is provided inside the camera body 3 and 
behind the flash window 12 in order to supply the necessary energy for the 
flash. 
FIG. 2 shows the direct viewfinder 4 in the extended position and the 
mechanism used to extend the direct viewfinder. The direct viewfinder 4 is 
mounted inside the camera body 3 by means of a guide pin 5. The attachment 
of the guide pin 5 to the direct viewfinder 4 is in a side wall 4a. The 
guide pin 5 is guided inside the lower mount 3c and an upper mount 3b. An 
elastic means 7 surrounds the guide pin 5 and is provided at that end 
facing the upper mount 3c with a lock washer 6 which is also firmly 
connected to the guide pin 5. The elastic means 7 is preferably a 
compression spring. The movement of the direct viewfinder 4 upwards out of 
the camera body, vertically to the optical axis, is limited by the upper 
mount 3b against which the lock washer 6 rests when the direct viewfinder 
4 is extended. As FIG. 2 shows, the direct viewfinder 4 projects above the 
camera body 3. Since the direct viewfinder 4 is made from a transparent, 
clear material, its interior is lined with a card 13, colored black to 
prevent reflection and also to mask the lenses (front lens 8 and eyepiece 
lens 9). 
The rear view of the camera body 3 is shown in FIG. 3. In the retracted 
position (bold line) of the direct viewfinder 4, the top edge 3a of the 
camera body 3 passes horizontally through the direct viewfinder 4. The 
retracted direct viewfinder 4 is flush with the contour of the camera 
formed by the front shell 1 and the rear wall 2. A recess, in which a 
retaining nose 10a engages, is provided in a wall 4b opposite the side 
wall 4a of the direct view finder 4. The retaining nose 10a is provided on 
a film transport lever 10. Operation of the film transport lever 10 in the 
direction A pulls the retaining nose 10a back out of the area of the 
recess in the wall 4b and releases the direct viewfinder 4. The direct 
viewfinder 4 is moved to its operating position (shown as dashed line in 
FIG. 3) by the elastic means 7. A slot 2a is provided on the rear wall 2 
of the camera body 3 in which the transport lever 10 is moved to convey 
the film further in direction A in order to bring a section of film to the 
position necessary for exposure. 
As FIG. 4 shows, the dimension of the direct viewfinder in the direction of 
the optical axis is slightly larger than the thickness of the camera, 
which is dictated by the dimensions of the front shell 1 and the rear wall 
2. The part of the direct viewfinder 4 with the front lens 8 projects past 
the front shell 1, and the part with the eyepiece lens 9 past the rear 
wall 2 of the camera. On the left, according to the conventions shown and 
next to the direct viewfinder 4, the flash window 12 with the associated 
switching arrangement 11 is provided (both shown by dashed lines). The 
card 13 lining the direct viewfinder 4 can have camera information printed 
on outside 13a. 
When the direct viewfinder is in the extended position, the user looks 
through it onto the object to be photographed (not shown). To do so, he 
holds the camera to one of his eyes such that the eyepiece lens 9 of the 
direct viewfinder 4 is at a distance X from the eye (see FIG. 5). The 
direct viewfinder 4 encloses with its dimensions the camera body 3. The 
part of the direct viewfinder 4 supporting the front lens 8 is guided in 
the recess 3d of the camera body. The direct viewfinder 4 is shown in FIG. 
6 in the retracted position, also in a side view. The direct viewfinder 4a 
is pushed in far enough to be flush with the contour of the rear wall 2. 
The part of the direct viewfinder 4 supporting the front lens 8 completely 
covers the recess 3d of the camera body 3. Similarly, the wall 4a of the 
direct viewfinder 4 is in contact with the upper mount 3b of the guide rod 
5. The guide rod 5 has at its end facing the upper mount 3b a pin 5a 
fastened in the wall 4a of the direct viewfinder 4. The upper mount 3b and 
the lower mount 3c are integral with the camera body 3. The elastic means 
7 is in contact with the lower mount 3c and is held in the pushed-together 
position by the lock washer 6. 
The object in accordance with the invention has been described in respect 
of a single-use camera, comprising essentially the camera body 3 with 
enclosing front shell 1 and rear wall 2. It is of course possible to 
arrange the direct viewfinder 4 in other cameras as well. Similar 
variations can easily be imagined as regarding the camera body. Variation 
can be carried out without departing from the scope of the claims.