Electrophotographic copying device

An electrophotographic copier for forming an image on the exposing device of the copier which includes a camera lens adapted to form an image of outside objects like a camera.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention refers to the presentation of images to an 
electrophotographic copying device. 
2. Description of the Prior Art 
Such a copying device has become known by a current prospectus of the firm 
Canon referring to a colour copying device "COLOR LASER COPIER-1". From 
this publication it is also known to place a dia-projector on the copier, 
the projector including a projection objective or lens to form an image on 
the entrance window of the copier. By this, electrophotographic copies can 
be made from diapositives. By this, it is possible to obtain more rapidly 
and simply paperprints from diapositives in comparison with chemographic 
reproduction. 
The known device, however, is restricted to the reproduction of 
diapositives. 
SUMMARY OF THE INVENTION 
It is the object of the present invention to provide a device of the kind 
mentioned above by which arbitrary objects can be copied in an 
electrophotographic way. 
According to the invention, an electrographic copier is provided with a 
camera objective or lens by which external objects can be formed to an 
image on the exposing device of the copier for the purpose of 
electrographic reproduction. By this, for the first time it is enabled to 
apply an electrographic copier as a kind of camera to copy arbitrary 
objects. For example, arbitrary relatively large images can be copied 
which normally is not possible with conventional copiers which usually are 
restricted to certain sizes of the image. 
Preferably, the objective includes means for varying the sharp focusing of 
the objective, thus making it possible to sharply reproduce objects having 
an essentially arbitrary distance. 
In the preferred embodiments, the objective includes means for varying the 
diaphragm of the objective, which makes it possible to influence the depth 
of the focal field which above all is of importance in connection with the 
reproduction of three-dimensional objects. 
Further, means for illuminating the object are preferably provided so that 
a high illumination of the object necessary for the projection can be 
secured under consideration of light losses. 
And preferably, the space between the objective and an image entrance 
window of the copier is light-tight enclosed so that disturbing light can 
be excluded from the electrophotographic copying process. 
According to another embodiment of the invention, the optical device can 
include a fibre optical device. By this, it is for example possible to 
copy interior body areas by means of an entroscope and to have the copies 
immediately available without a photochemic developing process. By the 
way, the invention enables the deflection of images from an X-ray screen 
onto the exposing device of the copier and to obtain a paperprint of the 
X-ray image. 
Some copiers include converting means so that it makes no difference how 
the image in the copier to be scanned is oriented. In case such converting 
means are not inherent in the copier, it is appropriate to provide a 
mirror arrangement by which the images of the object is turned about 
180.degree. so that in the copier a correctly oriented copying of the 
object takes place. 
If the illumination of the object is too weak, it can be appropriate to 
provide a low-light amplifier (multiplier) associated with the copier or 
the objective. 
In the drawings, two examples of the invention are diagrammatically 
illustrated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 shows a copier 1 which can be used as office copier and includes an 
entrance window 2 usually covered by a glass plate and normally serving as 
image carrier during the normal copying process. The usually provided, 
however not shown, cover covering the entrance window 2 is removed or 
turned away, respectively. 
With the invention, the copier 1 is to be used for the reproduction of a 
remotely placed object 3. This for example can be defined as an image 
plate whereon drawings or the like having a large format could be 
attached. 
The copier 1 is equipped with an objective 4 which is mounted on the top 
surface of the copier 1 by an arm 5. The objective 4 is of suitable 
structure and also of the kind which for example is used for large format 
cameras. 
In the embodiment shown, the axis of the objective 4 extends parallel to 
the surface of the entrance window 2 for leaving an access to the location 
where the object 3 is positioned. Therefore, a deflection mirror 6 is 
provided for the copier 1 including an angle of 45.degree. relative to the 
entrance window 2 or the axis of the objective 4, respectively, through 
which the objective 4 forms an image of the object 3 on the entrance 
window 2 as shown by the dashed lines. 
The objective 4 can be provided with a fixed focusing means. However, it is 
advantageous to provide a means for a variable focusing which in the 
embodiment shown is formed as a focusing rotary ring 7 at the objective 4. 
By this, different distances from the object 3 can by considered to 
achieve an exact range focus control. 
It is furthermore advantageous to provide means for a lens aperture setting 
in the form of a diaphragm ring 8 rotatably supported by the objective 4. 
By this, the focusing can be influenced above all with the reproduction of 
three-dimensional objects or to adjust a correct exposing with a 
predetermined constant illumination. 
As an alternative to the focusing rotary ring 7 for the variation of the 
focal depth, longitudinal adjustment means could be provided, for example 
including a threaded shaft by which the objective 4 can be displaced along 
its axis, e.g. relative to arm 5 or in conjunction with the arm 5 relative 
to the copier 1. 
In FIG. 1, further lamps 9 are shown, e.g. conventional photo lamps by 
which the object 3 can be illuminated in a suitable manner. 
If the environment is not bright, the space between the objective 4, the 
deflection mirror 6 and the entrance window 2 can be left free. However, 
if disturbing light is entering the entrance window 2, it can be 
advantageous to seal this space against light. To this purpose a cover 
sheet or enclosure 10 is provided which is attached to the objective 4 by 
a ring 11, the cover sheet 10 being attached to the edges of the mirror 6 
and to the housing of the copier 1 in a suitable manner. 
The objective 4 which is only provided for the purposes of the invention, 
can be releasably mounted in order to allow the application of the copier 
1 as normal office copier. The objective 4 for example can be removed in 
conjunction with arm 5. The deflection mirror 6 can be also releasably 
mounted, and the arm 5 in connection with the objective 4 and the mirror 6 
can be offered in the trade as retro-fit equipment. 
Instead of the shown objective 4 which merely includes a focus adjustment 
and a diaphragm adjustment, also a so-called zoom can be provided which 
includes an additional adjustment of the depth of the focus field. By 
this, also the reduction scale can be changed. It is clear that for such 
adjustment purposes also the exposing device of the copier 1 can be used 
which normally includes an objective having a diaphragm adjustment and in 
the most cases also adjustment means for the depth of the focus field. 
Finally, automatic foxusing means can also be provided. 
The copier according to the invention as well as the cited known copying 
device mentioned above, includes a plate- or sheet-like Fresnel lens as a 
part of its exposing device onto which the objective 4 forms an image, the 
Fresnel lens being placed on the entrance window 2 of the copier and 
serving for a uniformly directed illumination of the formate. This effect 
necessitates diffusing screen-like grounding of the back surface of the 
Fresnel lens. 
FIG. 2 diagrammatically shows a copier 1a which above its entrance window 
2a includes a deflection mirror 6a like mirror 6 of FIG. 1. The arm 5a 
releasably mounted on the top surface of the copier 1a retains a light 
fibre conductor 20 which at the front end has an objective 21 or lens in a 
manner as known per se. The light conductor 20 can for instance serve for 
medical entroscopying. The other end of the light conductor 20 is 
connected to an optical device 22 which for example may include a light 
amplifier from which the optical beam is transmitted to the deflection 
mirror 6a. 
It has to be noticed with respect to FIG. 1 that a further deflection 
mirror 12 (in dash-dotted lines) can be provided in order to form an image 
of an object on an image surface 13 by the objective 4. By this, the 
object is copied in the copier 1 in the correct position if the copier 1 
does not include converting means by which the images can be turned about 
180.degree..